Nerve cuff for disordered breathing therapy

Abstract

Examples of the disclosure include a nerve cuff configured to electrically couple to an implantable pulse generator. The nerve cuff includes a tubular cuff body configured to encircle a nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the nerve into the tubular cuff body, a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

Description

[0001] NERVE CUFF FOR DISORDERED BREATHING THERAPY

[0002] BACKGROUND

[0003] Nerve cuffs may be used to stimulate nerves in a patient’s body. A nerve cuff may be implanted so as to encircle a target nerve to deliver electrical stimulation to that target nerve. The nerve cuff includes electrodes configured to deliver the electrical stimulation. Furthermore, the nerve cuff is configured to electrically couple with an electrical stimulation energy generator, such as an external or internal stimulation pulse generator.

[0004] A nerve cuff may provide stimulation to a nerve that enervates at least one muscle responsible for functions of the respiratory system. Thus, such stimulation may be part of disordered breathing therapy, for example, for patients affected by sleep apnea.

[0005] SUMMARY

[0006] Examples of the methods and systems discussed herein are not limited in application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The methods and systems may be capable of implementation in other embodiments and of being practiced or of being carried out in various ways. Examples of specific implementations are provided herein for illustrative purposes and are not intended to be limiting. Acts, components, elements, and features discussed in connection with one or more examples may be configured to operate and / or be implemented in a similar role in other examples.

[0007] The phraseology and terminology used herein is for the purpose of description. References to examples, embodiments, components, elements, or acts of the systems and methods herein referred to in the singular may also embrace embodiments including a plurality. Similarly, references in plural to embodiments, components, elements, or acts may be implemented as a singularity. References in the singular or plural form may therefore not be intended to limit the presently disclosed systems or methods, their components, acts, or elements. The use herein of “including,” “comprising,” “having,” “containing,” “involving,” and variations so forth, may encompass the items listed thereafter and equivalents thereof as well as additional items. References to “or” may be construed as inclusive so that terms described using “or” may indicate a single, more than one, and all of the described terms. For example, the phrase “at least one of A or B” may refer A and / or B — that is, A only, B only, or A and B together. In addition, in the event of inconsistent usages of terms between this document and documents incorporated herein by reference, the term usage in the incorporated documents is supplementary to this document. For irreconcilable differences, the term usage in this document controls.

[0008] According to at least one aspect of the present disclosure

[0009] An implantable nerve cuff for electrically stimulating a nerve of a patient includes a tubular cuff body characterized by a longitudinal axis and having a proximal end at a first location along the longitudinal axis and a distal end at a second location along the longitudinal axis, the tubular cuff body configured to encircle a nerve approximately along the longitudinal axis of the tubular cuff body, the tubular cuff body including: an inner surface at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the nerve and the inner radial distance being approximately constant along the longitudinal axis, a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the nerve and characterized by a first arc length that is less than a circumference of the tubular cuff body, a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the first and second outer radial distances are approximately constant along the longitudinal axis, and a split extending from the inner surface to the first outer surface along the tubular cuff body parallel to the longitudinal axis, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the first outer surface, wherein the closure flap a) is configured to be fixedly coupled to the first section of the tubular cuff body and configured to be releasably coupled to the second section of the tubular cuff body in a closed flap position, b) has a flap thickness approximately equal to a difference between the first outer radial distance and the second outer radial distance such that the nerve cuff has an approximately constant cuff radius equal to the second outer radial distance with the closure flap in the closed flap position; and c) has an inner flap length approximately equal to the first arc length; and a plurality of electrodes disposed on the inner surface of the tubular cuff body and configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve.

[0010] In at least one example, the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to the proximal end relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to the distal end relative to the longitudinal axis than the pair of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

[0011] In at least one example, the pair of proximal electrode contacts includes a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts includes a first distal electrode contact and a second distal electrode contact, wherein the pair of middle electrode contacts includes a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

[0012] In at least one example, the first arrangement of electrode contacts is arranged in mirrorsymmetry with the second arrangement of electrode contacts across the longitudinal axis. In at least one example, the first proximal electrode contact and the second proximal electrode contact are arranged in mirror- symmetry across the longitudinal axis, wherein the first middle electrode contact and the second middle electrode contact are arranged in mirror- symmetry across the longitudinal axis, and wherein the first distal electrode contact and the second distal electrode contact are arranged in mirror symmetry across the longitudinal axis.

[0013] In at least one example, the first proximal electrode contact spans a first range of degrees along a circumference of the inner surface of the tubular cuff body; the first distal electrode contact spans a second range of degrees along the circumference of the inner surface of the tubular cuff body; the second proximal electrode contact spans a third range of degrees along the circumference of the inner surface of the tubular cuff body; the second distal electrode contact spans a fourth range of degrees along the circumference of the inner surface of the tubular cuff body; the first middle electrode contact spans a fifth range of degrees along the circumference of the inner surface of the tubular cuff body; and the second middle electrode contact spans a sixth range of degrees along the circumference of the inner surface of the tubular cuff body, and wherein the first range of degrees and the second range of degrees each overlap the fifth range of degrees and without overlapping each other, and the third range of degrees and the fourth range of degrees each overlap the sixth range of degrees and without overlapping each other.

[0014] In at least one example, the first range of degrees is contiguous with the second range of degrees, and the third range of degrees is contiguous with the fourth range of degrees. In at least one example, the first proximal electrode contact is longitudinally separated from the first middle electrode contact by a first spacing, the first distal electrode contact is longitudinally separated from the first middle electrode contact by a second spacing, the second proximal electrode contact is longitudinally separated from the second middle electrode contact by a third spacing, and the second distal electrode contact is longitudinally separated from the second middle electrode contact by a fourth spacing, and wherein the first spacing, the second spacing, the third spacing, and the fourth spacing are approximately equal to one another such that the first arrangement of electrode contacts is evenly spaced along the longitudinal axis and the second arrangement of electrode contacts is evenly spaced along the longitudinal axis.

[0015] In at least one example, the first proximal electrode contact and the second proximal electrode contact are located equidistant from and on opposite sides of the split, the first middle electrode contact and the second middle electrode contact are located equidistant from and on opposite sides of the split, and the first distal electrode contact and the second distal electrode contact are located equidistant from and on opposite sides of the split. In at least one example, a length-to-width aspect ratio of the proximal and distal pairs of electrode contacts is approximately 3:1, and a length-to-width aspect ratio of the pair of middle electrode contacts is approximately 2:1. In at least one example, each electrode contact of the pair of proximal electrode contacts, the pair of middle electrode contacts, and the pair of distal electrode contacts is shaped as quadrilateral including a rounded-corner rectangle. In at least one example, a length of each electrode contact of the proximal and distal pairs of electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, a length of each electrode contact of the proximal and distal pairs of electrode contacts is between approximately 2 - 3 mm, and a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm.

[0016] In at least one example, the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode.

[0017] In at least one example, the tubular cuff body includes a plurality of conductor-access pathways in a conductor- access section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and the nerve cuff further includes a plurality of conductors each disposed at a respective pathway of the plurality of conductor-access pathways and electrically coupled a respective electrode of the plurality of electrodes. In at least one example, the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another via a second pair of conductors of the plurality of conductors.

[0018] In at least one example, the plurality of conductors is configured to create six selectable anode-cathode pairs of electrodes to selectively steer the stimulation current. In at least one example, the six selectable anode-cathode pairs of electrodes are the proximal electrode and the first middle electrode, the proximal electrode and the second middle electrode, the distal electrode and the first middle electrode, the distal electrode and the second middle electrode, the proximal electrode and the distal electrode, and the first middle electrode and the second middle electrode. In at least one example, the plurality of conductors is configured to electrically couple to an implantable pulse generator (IPG) configured to control an anode-cathode pair selection. In at least one example, each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof.

[0019] In at least one example, the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and an arc length of the conductor-access section along the second outer surface is equal to the second arc length. In at least one example, a length of the tubular cuff body is approximately 12.4 mm. In at least one example, the inner radial distance is approximately 1 mm and wherein the second outer radial distance is approximately 2 mm. In at least one example, a length of the tubular cuff body is in a range of 5-15 mm. In at least one example, the inner radial distance is in a range of 0.5-1.5 mm. In at least one example, the second outer radial distance is in a range of 1.5-2.5 mm. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap and the second outer surface of the tubular cuff body have an approximately constant radius relative to the longitudinal axis such that the nerve cuff is free of any radial protrusions from the outer surface of the closure flap and the second outer surface.

[0020] In at least one example, the outer surface of the closure flap has a third arc length and a circumference of the nerve cuff is approximately equal to a sum of the third arc length and the second arc length. In at least one example, the closure flap extends along an entire length of the nerve cuff from the proximal end of the tubular cuff body to the distal end of the tubular cuff body. In at least one example, at least one of the closure flap or the first outer surface of the first section of the tubular cuff body includes or is coupled to a bonding material such that the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material. In at least one example, the closure flap is configured to be in physical contact with the first outer surface of the second section of the tubular cuff body when the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

[0021] In at least one example, the nerve cuff includes at least one flexion zone. In at least one example, the at least one flexion zone includes a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body. In at least one example, the at least one flexion zone includes a groove in a wall of the tubular cuff body. In at least one example, the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards the second outer surface to form a flexion zone wall bounded by the second outer surface. In at least one example, the at least one flexion zone includes a plurality of perforations, each perforation including a respective opening through the tubular cuff body.

[0022] In at least one example, the at least one flexion zone is positioned radially opposite the split. In at least one example, the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split. In at least one example, the opening defined by the split in the tubular cuff body is characterized by a first width from the first outer surface of the first section to the first outer surface of the second section, and a second width from the inner surface of the first section to the inner surface of the second section, and the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone. In at least one example, the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width. In at least one example, the nerve includes a cervical phrenic nerve. In at least one example, the nerve cuff includes one or more sensor electrodes. In at least one example, the one or more sensor electrodes include at least one of an electromyography sensor, an accelerometer, or an acoustic sensor.

[0023] Examples of the disclosure include a treatment system for treating disordered breathing in a patient, the system including: an implantable pulse generator (IPG); and a nerve cuff electrically coupled to the IPG, the nerve cuff including a tubular cuff body configured to encircle a nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the nerve into the tubular cuff body, a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve; and a plurality of conductors coupled to the IPG and to the plurality of electrodes.

[0024] In at least one example, the tubular cuff body is characterized by the longitudinal axis and has a proximal end at a first location along the longitudinal axis and a distal end at a second location along the longitudinal axis, wherein the inner surface is at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body including: a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the nerve and characterized by a first arc length along a first range of degrees, the first arc length being less than a circumference of the tubular cuff body, a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the first and second outer radial distances are approximately constant along the longitudinal axis, and the split extending from the inner surface to the first outer surface along the tubular cuff body parallel to the longitudinal axis, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section, and wherein the closure flap is configured to be fixedly coupled to the first section of the tubular cuff body and configured to be releasably coupled to the second section of the tubular cuff body in a closed flap position, has a flap thickness approximately equal to a difference between the first outer radial distance and the second outer radial distance such that the nerve cuff has an approximately constant cuff radius equal to the second outer radial distance with the closure flap in the closed flap position; has an inner flap length approximately equal to the first arc length; and is configured to wrap around the first outer surface.

[0025] In at least one example, the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pair of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

[0026] In at least one example, the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode. In at least one example, the tubular cuff body includes a plurality of conductor-access pathways in a conductoraccess section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and each conductor of the plurality of conductors is disposed at a respective pathway of the plurality of conductor- access pathways and electrically coupled a respective electrode of the plurality of electrodes.

[0027] In at least one example, the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to via a second pair of conductors of the plurality of conductors. In at least one example, the plurality of conductors is configured to create six selectable anode-cathode pairs of electrodes to selectively steer the stimulation current. In at least one example, the six selectable anode-cathode pairs of electrodes are the proximal electrode and the first middle electrode, the proximal electrode and the second middle electrode, the distal electrode and the first middle electrode, the distal electrode and the second middle electrode, the proximal electrode and the distal electrode, the first middle electrode and the second middle electrode.

[0028] In at least one example, the IPG is configured to control an anode-cathode pair selection. In at least one example, the IPG is configured to control the anode-cathode pair selection based on a user-selected anode-cathode pair selection. In at least one example, the IPG is configured to control the anode-cathode pair selection based on sensory feedback information indicative of a sensory response by the patient to the stimulation current. In at least one example, the sensory feedback information includes heart-rate information. In at least one example, the sensory feedback information includes skin-conductivity information. In at least one example, the sensory feedback information includes breathing-rate information. In at least one example, the sensory feedback information includes user-feedback information. In at least one example, the IPG is configured to apply approximately 3 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate approximately 3 mA of current. In at least one example, the IPG is configured to apply a range of 0-16 V across an anodc-cathodc pair selected from the six selectable anode-cathode pairs and generate a range of 0-10 mA of current. In at least one example, the pair of proximal electrode contacts includes a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts includes a first distal electrode contact and a second distal electrode contact, wherein the pair of middle electrode contacts includes a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

[0029] In at least one example, the first arrangement of electrode contacts is arranged in mirrorsymmetry with the second arrangement of electrode contacts across the longitudinal axis. In at least one example, the first proximal electrode contact and the second proximal electrode contact are arranged in mirror- symmetry across the longitudinal axis, wherein the first middle electrode contact and the second middle electrode contact are arranged in mirror- symmetry across the longitudinal axis, and wherein the first distal electrode contact and the second distal electrode contact are arranged in mirror symmetry across the longitudinal axis.

[0030] In at least one example, the first proximal electrode contact spans a first range of degrees along a circumference of the inner surface of the tubular cuff body; the first distal electrode contact spans a second range of degrees along the circumference of the inner surface of the tubular cuff body; the second proximal electrode contact spans a third range of degrees along the circumference of the inner surface of the tubular cuff body; the second distal electrode contact spans a fourth range of degrees along the circumference of the inner surface of the tubular cuff body; the first middle electrode contact spans a fifth range of degrees along the circumference of the inner surface of the tubular’ cuff body; and the second middle electrode contact spans a sixth range of degrees along the circumference of the inner surface of the tubular cuff body, and wherein: the first range of degrees and the second range of degrees each overlap the fifth range of degrees and without overlapping each other, and the third range of degrees and the fourth range of degrees each overlap the sixth range of degrees and without overlapping each other. In at least one example, the first range of degrees is contiguous with the second range of degrees, and the third range of degrees is contiguous with the fourth range of degrees. In at least one example, the first proximal electrode contact is longitudinally separated from the first middle electrode contact by a first spacing, the first distal electrode contact is longitudinally separated from the first middle electrode contact by a second spacing, the second proximal electrode contact is longitudinally separated from the second middle electrode contact by a third spacing, and the second distal electrode contact is longitudinally separated from the second middle electrode contact by a fourth spacing, and wherein the first spacing, the second spacing, the third spacing, and the fourth spacing are approximately equal to one another such that the first arrangement of electrode contacts is evenly spaced along the longitudinal axis and the second arrangement of electrode contacts is evenly spaced along the longitudinal axis.

[0031] In at least one example, the first proximal electrode contact and the second proximal electrode contact are located equidistant from and on opposite sides of the split, wherein the first middle electrode contact and the second middle electrode contact are located equidistant from and on opposite sides of the split, and wherein the first distal electrode contact and the second distal electrode contact are located equidistant from and on opposite sides of the split. In at least one example, a length-to-width aspect ratio of the proximal and distal pairs of electrode contacts is approximately 3:1, and wherein a length-to-width aspect ratio of the pair of middle electrode contacts is approximately 2:1. In at least one example, each electrode contact of the pair of proximal electrode contacts, the pair of middle electrode contacts, and the pair of distal electrode contacts is shaped as quadrilateral including a rounded-comer rectangle.

[0032] In at least one example, a length of each electrode contact of the proximal and distal pairs of electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is between approximately 2 - 3 mm, and wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm. In at least one example, each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof. In at least one example, the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and an outer surface of the tubular cuff body, and wherein an arc length of the conductor-access section along the second outer surface is equal to an arc length of the outer surface.

[0033] In at least one example, a length of the tubular cuff body is approximately 12.4 mm. In at least one example, the inner radial distance is approximately 1 mm and wherein the second outer radial distance is approximately 2 mm. In at least one example, a length of the tubular cuff body is in a range of 5-15 mm. In at least one example, the inner radial distance is in a range of 0.5-1.5 mm. In at least one example, the second outer radial distance is in a range of 1.5-2.5 mm. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap and the second outer surface of the tubular cuff body have an approximately constant radius relative to the longitudinal axis such that the nerve cuff is free of any radial protrusions from the outer surface of the closure flap and the second outer surface.

[0034] In at least one example, the outer surface of the closure flap has a third arc length and a circumference of the nerve cuff is approximately equal to a sum of the third arc length and the second arc length. In at least one example, the closure flap extends along an entire length of the nerve cuff from the proximal end of the tubular cuff body to the distal end of the tubular cuff body. In at least one example, at least one of the closure flap or the first outer surface of the first section of the tubular cuff body includes or is coupled to a bonding material such that the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material. In at least one example, the closure flap is configured to be in physical contact with the first outer surface of the second section of the tubular cuff body when the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

[0035] In at least one example, the treatment system includes at least one flexion zone. In at least one example, the at least one flexion zone includes a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body. In at least one example, the at least one flexion zone includes a groove in a wall of the tubular cuff body. In at least one example, the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards the second outer surface to form a flexion zone wall bounded by the second outer surface. In at least one example, the at least one flexion zone includes a plurality of perforations, each perforation including a respective opening through the tubular cuff body. In at least one example, the at least one flexion zone is positioned radially opposite the split. In at least one example, the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split.

[0036] In at least one example, the opening defined by the split in the tubular cuff body is characterized by a first width from the first outer surface of the first section to the first outer surface of the second section, and a second width from the inner surface of the first section to the inner surface of the second section. In at least one example, the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width. In at least one example, the nerve includes a cervical phrenic nerve. In at least one example, the IPG is configured to control an anode-cathode pair selection from the plurality of electrodes to selectively steer the stimulation current towards the motor fibers of the nerve and away from the sensory fibers of the nerve.

[0037] In at least one example, the IPG is configured to control the anode-cathode pair selection from the plurality of electrodes based on a user-selected anode-cathode pair selection. In at least one example, the IPG is configured to control the anode-cathode pair selection based on sensory feedback information indicative of a sensory response by the patient to the stimulation current. In at least one example, the sensory feedback information includes heart-rate information. In at least one example, the sensory feedback information includes skin-conductivity information. In at least one example, the sensory feedback information includes breathing-rate information. In at least one example, the sensory feedback information includes user-feedback information.

[0038] Examples of the disclosure include a nerve cuff for treating disordered breathing in a patient, the nerve cuff comprising: a tubular cuff body configured to encircle a phrenic nerve positioned approximately along a longitudinal axis of the tubular- cuff body, a split configured to enable insertion of the phrenic nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the phrenic nerve and away from sensory fibers of the phrenic nerve; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

[0039] In at least one example, the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pairs of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

[0040] In at least one example, the pair of proximal electrode contacts comprises a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts comprises a first distal electrode contact and a second distal electrode contact, wherein the pair of middle electrode contacts comprises a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

[0041] In at least one example, the first arrangement of electrode contacts is arranged in mirrorsymmetry with the second arrangement of electrode contacts across the longitudinal axis. In at least one example, a length of each electrode contact of the pairs of proximal and distal electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the pairs of proximal and distal electrode contacts is between approximately 2 - 3 mm, wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm, and wherein a length to width ratio of each electrode contact of the pairs of proximal, middle, and distal electrodes is approximately 2:1, 3:1, or 4:1.

[0042] In at least one example, the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein: a) the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, b) the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and c) the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode.

[0043] In at least one example, the tubular cuff body comprises a plurality of conductor- access pathways in a conductor- access section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor-access pathways and electrically coupled a respective electrode of the plurality of electrodes.

[0044] In at least one example, the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another via a second pair of conductors of the plurality of conductors. In at least one example, the plurality of conductors is configured to create six selectable anodecathode pairs of electrodes to selectively steer the stimulation current. In at least one example, the IPG is configured to control an anode-cathode pair selection from the plurality of electrodes to selectively steer the stimulation current towards the motor fibers of the phrenic nerve and away from the sensory fibers of the phrenic nerve.

[0045] In at least one example, the IPG is configured to control the anode-cathode pair selection via the plurality of conductors. In at least one example, the IPG is configured to apply approximately 3 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate approximately 3 mA of current. In at least one example, the IPG is configured to apply a range of 0-16 V across an anode-cathode pair selected from the six selectable anodecathode pairs and generate a range of 0-10 mA of current. In at least one example, each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular' cuff body, or a combination thereof.

[0046] In at least one example, the inner surface is at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the phrenic nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body further comprising: a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the phrenic nerve and characterized by a first arc length that is less than a circumference of the tubular- cuff body, and a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the phrenic nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and wherein an arc length of the conductor-access section along the second outer surface is equal to the second arc length.

[0047] In at least one example, the inner radial distance is approximately 1 mm and wherein the second outer radial distance is approximately 2 mm. In at least one example, the inner radial distance is in a range of 0.5- 1.5 mm. In at least one example, the second outer radial distance is in a range of 1-2.5 mm. In at least one example, a length of the tubular cuff body is in a range of 5-15 mm. In at least one example, the length of the tubular cuff body is approximately 12.4 mm. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap is free of any radial protrusions. In at least one example, the closure flap extends along an entire length of the nerve cuff from a proximal end of the tubular cuff body to a distal end of the tubular- cuff body.

[0048] In at least one example, the closure flap extends along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to a flexion zone. In at least one example, the arc length corresponds to an angular range that terminates prior to a midline of the flexion zone. In at least one example, the cuff includes at least one flexion zone. In at least one example, the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body. In at least one example, the at least one flexion zone comprises a groove in a wall of the tubular cuff body. In at least one example, the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards an outer surface of the tubular cuff body to form a flexion zone wall bounded by the outer surface.

[0049] In at least one example, the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body. In at least one example, the at least one flexion zone is positioned radially opposite the split. In at least one example, the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split. In at least one example, the opening defined by the split in the tubular cuff body is characterized by a first width from an outer surface of the first section to an outer surface of the second section, and a second width from an inner surface of the first section to an inner surface of the second section, and wherein the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone. In at least one example, the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width. In at least one example, the phrenic nerve comprises a cervical phrenic nerve.

[0050] Examples of the disclosure include a nerve cuff for treating disordered breathing in a patient, the nerve cuff comprising: a tubular cuff body configured to encircle an ansa cervicalis positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the ansa cervicalis into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

[0051] In at least one example, the plurality of electrodes is physically arranged as a proximal electrode contact, a middle electrode contact, and a distal electrode contact, wherein the proximal electrode contact is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the middle or distal electrode contact, wherein the distal electrode contact is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the proximal or middle electrode contacts, and wherein the middle electrode contact is located between the proximal electrode contact and the distal electrode contact relative to the longitudinal axis.

[0052] In at least one example, the proximal electrode contact, the middle electrode contact, and the distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body without any electrodes in the second section of the tubular cuff body. In at least one example, a length of each electrode contact of the proximal and distal electrode contacts is less than a length of the middle electrode contact. In at least one example, a length of each electrode contact of the proximal and distal electrode contacts is between approximately 1.5 - 2.0 mm. In at least one example, a length of the middle electrode contact is between approximately 2.5 - 3.0 mm. In at least one example, a length to width ratio of each electrode contact of the pairs of proximal, middle, and distal electrodes is approximately 2:1 or 3:1. In at least one example, the nerve cuff is configured to provide non- selective stimulation without current steering.

[0053] In at least one example, two of the proximal, middle, and distal electrode contacts are electrically coupled and one of the proximal, middle, and distal electrode contacts is electrically isolated from the two electrically coupled electrode contacts. In at least one example, a) the proximal electrode contact is electrically coupled to the distal electrode contact, and b) the middle electrode contact is electrically isolated from the proximal electrode contact and the distal electrode contact. In at least one example, a) the middle electrode contact is electrically coupled to one of the distal electrode contact or the proximal electrode contact, and b) the other of the distal electrode contact or the proximal electrode contact is electrically isolated from the electrically coupled electrode contacts.

[0054] In at least one example, the nerve cuff is configured to provide selective stimulation through current steering. In at least one example, each of the proximal, middle, and distal electrode contacts is electrically isolated from others of the proximal, middle, and distal electrode contacts. In at least one example, the tubular cuff body comprises a plurality of conductor-access pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from a proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor-access pathways and electrically coupled a respective electrode of the plurality of electrodes.

[0055] In at least one example, the conductor-access section protrudes from a surface of the tubular cuff body. In at least one example, the protruding conductor-access section extends along the tubular cuff body parallel to the longitudinal axis. In at least one example, the IPG is configured to generate approximately 0.3 - 1 mA of stimulation current. In at least one example, the IPG is configured to apply a range of 0-16 V across anode-cathode pairs and generate a range of 0-10 mA of current. In at least one example, an inner radial distance is approximately 0.5 mm and a second outer radial distance is approximately 1.3 mm.

[0056] In at least one example, a length of the tubular cuff body is in a range of 5-15 mm. In at least one example, an inner radial distance is in a range of 0.5- 1.5 mm. In at least one example, a length of the tubular cuff body is approximately 10 mm. In at least one example, a second outer radial distance is in a range of 0.9- 1.7. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap is free of any radial protrusions from an outer surface of the closure flap. In at least one example, the closure flap extends along an entire length of the nerve cuff from a proximal end of the tubular cuff body to a distal end of the tubular cuff body.

[0057] In at least one example, the closure flap extends along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to a flexion zone. In at least one example, the arc length corresponds to an angular range that terminates prior to a midline of the flexion zone. In at least one example, the cuff includes at least one flexion zone. In at least one example, the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body. In at least one example, the at least one flexion zone comprises a groove in a wall of the tubular cuff body. In at least one example, the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards an outer surface of the tubular cuff body to form a flexion zone wall bounded by the outer surface.

[0058] In at least one example, the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body. In at least one example, the at least one flexion zone is positioned radially opposite the split. In at least one example, the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split. In at least one example, the opening defined by the split in the tubular cuff body is characterized by a first width from an outer surface of the first section to an outer surface of the second section, and a second width from an inner surface of the first section to an inner surface of the second section, and wherein the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone. In at least one example, the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width. Examples of the disclosure include a treatment system for treating sleep disordered breathing in a patient, the system comprising: an implantable pulse generator (IPG); and a nerve cuff configured to electrically couple to the IPG, the nerve cuff comprising: a tubular cuff body configured to encircle a phrenic nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the phrenic nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the phrenic nerve and away from sensory fibers of the phrenic nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

[0059] Examples of the disclosure include a treatment system for treating sleep disordered breathing in a patient, the system comprising: an implantable pulse generator (IPG); and a nerve cuff configured to electrically couple to the IPG, the nerve cuff comprising: a tubular cuff body configured to encircle an ansa cervicalis positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the ansa cervicalis into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

[0060] Examples of the disclosure include a method of implanting a nerve cuff for treating sleep disordered breathing in a patient, the method comprising: making a first incision at a first implant location on the patient; placing the nerve cuff around a target nerve in the first implant location, the nerve cuff comprising a plurality of electrodes; subcutaneously tunneling at least one electrical lead extending from the nerve cuff to a second implant location for an implantable pulse generator (IPG); and electrically testing the plurality of electrodes with an external pulse generator.

[0061] In at least one example, the method includes making a second incision at a second implant location on the patient; placing the IPG subcutaneously at the second implant location; and connecting the nerve cuff to the implantable pulse generator. In at least one example, the method includes closing the second incision. In at least one example, the method includes closing the first incision. In at least one example, placing the nerve cuff around the target nerve comprising placing the nerve cuff around a phrenic nerve. In at least one example, the phrenic nerve comprises a cervical phrenic nerve.

[0062] In at least one example, the nerve cuff comprises: a tubular cuff body configured to encircle the phrenic nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body; a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the phrenic nerve and away from sensory fibers of the phrenic nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes. In at least one example, placing the nerve cuff around the target nerve comprising placing the nerve cuff around an ansa cervicalis.

[0063] In at least one example, the nerve cuff comprises: a tubular cuff body configured to encircle the ansa cervicalis positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the ansa cervicalis into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body; a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

[0064] In at least one example, placing the nerve cuff around the target nerve comprises: grasping the nerve cuff with a first surgical instrument; positioning the nerve cuff on a first side of the target nerve; reaching under the target nerve from a second side of the target nerve with a second surgical instrument to open the nerve cuff; drawing the nerve cuff under the target nerve; locating a flexion zone of the nerve cuff below the target nerve; and releasing the nerve cuff from the first and second surgical instruments to allow the nerve cuff to encircle the target nerve.

[0065] In at least one example, the first side of the target nerve is a medial side and the second side is a lateral side, and the method includes drawing the nerve cuff under the target nerve from the medial side to the lateral side. In at least one example, the first side of the target nerve is a lateral side and the second side is a medial side, and the method includes drawing the nerve cuff under the target nerve from the lateral side to the medial side. In at least one example, grasping the nerve cuff with the first surgical instrument comprising grasping a nerve cuff closure flap or at least one nerve cuff suture.

[0066] In at least one example, grasping the nerve cuff with the second surgical instrument comprising grasping a nerve cuff closure flap or at least one nerve cuff suture. In at least one example, the method includes testing nerve activation from the nerve cuff. In at least one example, the method includes adjusting a position of the nerve cuff along or around the target nerve based on the nerve activation testing. In at least one example, the method includes anchoring the at least one electrical lead to surrounding tissues.

[0067] Examples of the disclosure include a nerve cuff for treating disordered breathing in a patient, the nerve cuff comprising: a tubular cuff body configured to encircle a hypoglossal nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the hypoglossal nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

[0068] In at least one example, the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pairs of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

[0069] In at least one example, the tubular cuff body comprises a plurality of conductor- access pathways in a conductor- access section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from a proximal end of the tubular- cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of con ductor- access pathways and electrically coupled a respective electrode of the plurality of electrodes.

[0070] In at least one example, each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof. In at least one example, the inner surface is at an inner radial distance from the longitudinal axis and configured to face towards the hypoglossal nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body further comprising; a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the hypoglossal nerve and characterized by a first arc length that is less than a circumference of the tubular cuff body, and a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the hypoglossal nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and wherein an arc length of the conductor-access section along the second outer surface is equal to the second arc length.

[0071] In at least one example, the inner radial distance is approximately 1.0 mm and wherein the second outer radial distance is approximately 2 mm. In at least one example, the inner radial distance is in a range of 0.5- 1.5 mm. In at least one example, the second outer radial distance is in a range of 1-2.5 mm. In at least one example, a length of the tubular cuff body is in a range of 5-15 mm. In at least one example, a length of the tubular cuff body is approximately 12.4 mm. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap is free of any radial protrusions. In at least one example, the closure flap extends along an entire length of the nerve cuff from a proximal end of the tubular cuff body to a distal end of the tubular cuff body.

[0072] In at least one example, the closure flap extends along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to a flexion zone. In at least one example, the arc length corresponds to an angular range that terminates prior to a mid- line of the flexion zone. In at least one example, the flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards an outer surface of the tubular cuff body to form a flexion zone wall bounded by the outer surface. In at least one example, the flexion zone is positioned radially opposite the split. In at least one example, the tubular cuff body is configured to rotate about the flexion zone to expand a width of the split. In at least one example, the plurality of electrodes are configured to selectively steer stimulation of the hypoglossal nerve. In at least one example, the plurality of electrodes are configured for non-selective stimulation of the hypoglossal nerve.

[0073] Examples of the disclosure include an implantable nerve cuff for electrically stimulating a nerve of a patient comprising: a tubular cuff body characterized by a longitudinal axis and having a proximal end at a first location along the longitudinal axis and a distal end at a second location along the longitudinal axis, the tubular cuff body configured to encircle a nerve approximately along the longitudinal axis of the tubular cuff body, the tubular cuff body comprising: an inner surface at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the nerve and the inner radial distance being approximately constant along the longitudinal axis, a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the nerve and characterized by a first arc length that is less than a circumference of the tubular cuff body, a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the first and second outer radial distances are approximately constant along the longitudinal axis, and a split extending from the inner surface to the first outer surface along the tubular cuff body parallel to the longitudinal axis, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the first outer surface, wherein the closure flap a) is configured to be fixedly coupled to the first section of the tubular cuff body and configured to be releasably coupled to the second section of the tubular cuff body in a closed flap position, b) has a flap thickness approximately equal to a difference between the first outer radial distance and the second outer radial distance such that the nerve cuff has an approximately constant cuff radius equal to the second outer radial distance with the closure flap in the closed flap position; and c) has an inner flap length greater than or approximately equal to the first arc length and less than the circumference of the tubular cuff body; and a plurality of electrodes disposed on the inner surface of the tubular cuff body and configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve.

[0074] In at least one example, the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to the proximal end relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to the distal end relative to the longitudinal axis than the pair of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

[0075] In at least one example, the pair of proximal electrode contacts comprises a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts comprises a first distal electrode contact and a second distal electrode contact, wherein the pair of middle electrode contacts comprises a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

[0076] In at least one example, the first arrangement of electrode contacts is arranged in mirrorsymmetry with the second arrangement of electrode contacts across the longitudinal axis. In at least one example, the first proximal electrode contact and the second proximal electrode contact are arranged in mirror- symmetry across the longitudinal axis, wherein the first middle electrode contact and the second middle electrode contact are arranged in mirror- symmetry across the longitudinal axis, and wherein the first distal electrode contact and the second distal electrode contact are arranged in mirror symmetry across the longitudinal axis. In at least one example, the first proximal electrode contact spans a first range of degrees along a circumference of the inner surface of the tubular cuff body; the first distal electrode contact spans a second range of degrees along the circumference of the inner surface of the tubular cuff body; the second proximal electrode contact spans a third range of degrees along the circumference of the inner surface of the tubular cuff body; the second distal electrode contact spans a fourth range of degrees along the circumference of the inner surface of the tubular cuff body; the first middle electrode contact spans a fifth range of degrees along the circumference of the inner surface of the tubular' cuff body; and the second middle electrode contact spans a sixth range of degrees along the circumference of the inner surface of the tubular cuff body, and wherein: the first range of degrees and the second range of degrees each overlap the fifth range of degrees and without overlapping each other, and the third range of degrees and the fourth range of degrees each overlap the sixth range of degrees and without overlapping each other.

[0077] In at least one example, the first range of degrees is contiguous with the second range of degrees, and the third range of degrees is contiguous with the fourth range of degrees. In at least one example, the first proximal electrode contact is longitudinally separated from the first middle electrode contact by a first spacing, the first distal electrode contact is longitudinally separated from the first middle electrode contact by a second spacing, the second proximal electrode contact is longitudinally separated from the second middle electrode contact by a third spacing, and the second distal electrode contact is longitudinally separated from the second middle electrode contact by a fourth spacing, and wherein the first spacing, the second spacing, the third spacing, and the fourth spacing are approximately equal to one another such that the first arrangement of electrode contacts is evenly spaced along the longitudinal axis and the second arrangement of electrode contacts is evenly spaced along the longitudinal axis.

[0078] In at least one example, the first proximal electrode contact and the second proximal electrode contact are located equidistant from and on opposite sides of the split, wherein the first middle electrode contact and the second middle electrode contact are located equidistant from and on opposite sides of the split, and wherein the first distal electrode contact and the second distal electrode contact are located equidistant from and on opposite sides of the split. In at least one example, a length-to-width aspect ratio of the proximal and distal pairs of electrode contacts is approximately 3:1, and wherein a length-to-width aspect ratio of the pair of middle electrode contacts is approximately 2:1. In at least one example, each electrode contact of the pair of proximal electrode contacts, the pair of middle electrode contacts, and the pair of distal electrode contacts is shaped as quadrilateral comprising a rounded-corner rectangle. In at least one example, a length of each electrode contact of the proximal and distal pairs of electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is between approximately 2 - 3 mm, and wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm.

[0079] In at least one example, the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein: a) the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, b) the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and c) the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode.

[0080] In at least one example, the tubular cuff body comprises a plurality of conductor- access pathways in a conductor- access section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from the proximal end of the tubular- cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor-access pathways and electrically coupled a respective electrode of the plurality of electrodes.

[0081] In at least one example, the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and wherein the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another via a second pair of conductors of the plurality of conductors. In at least one example, the plurality of conductors is configured to create six selectable anodecathode pairs of electrodes to selectively steer the stimulation current. In at least one example, the six selectable anode-cathode pairs of electrodes are a) the proximal electrode and the first middle electrode, b) the proximal electrode and the second middle electrode, c) the distal electrode and the first middle electrode, d) the distal electrode and the second middle electrode, e) the proximal electrode and the distal electrode, and f) the first middle electrode and the second middle electrode.

[0082] In at least one example, the plurality of conductors is configured to electrically couple to an implantable pulse generator (IPG) configured to control an anode-cathode pair selection. In at least one example, each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof. In at least one example, the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and wherein an arc length of the conductor-access section along the second outer surface is equal to the second arc length.

[0083] In at least one example, a length of the tubular cuff body is in a range of 5-15 mm. In at least one example, a length of the tubular cuff body is approximately 12.4 mm. In at least one example, the inner radial distance is approximately 1 mm and wherein the second outer radial distance is approximately 2 mm. In at least one example, the inner radial distance is in a range of 0.5- 1.5 mm. In at least one example, the second outer radial distance is in a range of 1.5-2.5 mm. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap and the second outer surface of the tubular cuff body have an approximately constant radius relative to the longitudinal axis such that the nerve cuff is free of any radial protrusions from the outer surface of the closure flap and the second outer surface.

[0084] In at least one example, the outer surface of the closure flap has a third arc length and a circumference of the nerve cuff is approximately equal to a sum of the third arc length and the second arc length. In at least one example, the closure flap extends along an entire length of the nerve cuff from the proximal end of the tubular cuff body to the distal end of the tubular cuff body. In at least one example, at least one of the closure flap or the first outer surface of the first section of the tubular cuff body comprises or is coupled to a bonding material such that the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material. In at least one example, the closure flap is configured to be in physical contact with the first outer surface of the second section of the tubular cuff body when the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

[0085] In at least one example, the cuff includes at least one flexion zone. In at least one example, the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body. In at least one example, the at least one flexion zone comprises a groove in a wall of the tubular cuff body. In at least one example, the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards the second outer surface to form a flexion zone wall bounded by the second outer surface. In at least one example, the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body.

[0086] In at least one example, the at least one flexion zone is positioned radially opposite the split. In at least one example, the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split. In at least one example, the opening defined by the split in the tubular cuff body is characterized by a first width from the first outer surface of the first section to the first outer surface of the second section, and a second width from the inner surface of the first section to the inner surface of the second section, and wherein the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone.

[0087] In at least one example, the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width. In at least one example, the nerve comprises a cervical phrenic nerve. In at least one example, the cuff includes one or more sensor electrodes. In at least one example, the one or more sensor electrodes comprise at least one of an electromyography sensor, an accelerometer, or an acoustic sensor.

[0088] Examples of the disclosure include a treatment system for treating disordered breathing in a patient, the system comprising: an implantable pulse generator (IPG); and a nerve cuff configured to electrically couple to the IPG, the nerve cuff comprising: a tubular cuff body configured to encircle a nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the nerve into the tubular cuff body, a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes. In at least one example, the tubular cuff body is characterized by the longitudinal axis and has a proximal end at a first location along the longitudinal axis and a distal end at a second location along the longitudinal axis, wherein the inner surface is at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body comprising: a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the nerve and characterized by a first arc length along a first range of degrees, the first arc length being less than a circumference of the tubular cuff body, a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the first and second outer radial distances are approximately constant along the longitudinal axis, and the split extending from the inner surface to the first outer surface along the tubular cuff body parallel to the longitudinal axis, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section, and wherein the closure flap a) is configured to be fixedly coupled to the first section of the tubular cuff body and configured to be releasably coupled to the second section of the tubular cuff body in a closed flap position, b) has a flap thickness approximately equal to a difference between the first outer radial distance and the second outer radial distance such that the nerve cuff has an approximately constant cuff radius equal to the second outer radial distance with the closure flap in the closed flap position; c) has an inner flap length approximately equal to the first arc length; and d) is configured to wrap around the first outer surface.

[0089] In at least one example, the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pair of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

[0090] In at least one example, the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein: a) the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, b) the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and c) the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode. In at least one example, the tubular cuff body comprises a plurality of conductoraccess pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductor-access pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein each conductor of the plurality of conductors is disposed at a respective pathway of the plurality of conductor-access pathways and electrically coupled a respective electrode of the plurality of electrodes.

[0091] In at least one example, the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and wherein the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to via a second pair of conductors of the plurality of conductors. In at least one example, the plurality of conductors is configured to create six selectable anode-cathode pairs of electrodes to selectively steer the stimulation current. In at least one example, the six selectable anode-cathode pairs of electrodes are a) the proximal electrode and the first middle electrode, b) the proximal electrode and the second middle electrode, c) the distal electrode and the first middle electrode, d) the distal electrode and the second middle electrode, e) the proximal electrode and the distal electrode, f) the first middle electrode and the second middle electrode.

[0092] In at least one example, the IPG is configured to control an anode-cathode pair selection. In at least one example, the IPG is configured to control the anode-cathode pair selection based on a user-selected anode-cathode pair selection. In at least one example, the IPG is configured to control the anode-cathode pair selection based on sensory feedback information indicative of a sensory response by the patient to the stimulation current. In at least one example, the sensory feedback information includes one or more of heart-rate information, skin-conductivity information, breathing-rate information, user-feedback information. In at least one example, the IPG is configured to apply approximately 3 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate approximately 3 mA of current.

[0093] In at least one example, the IPG is configured to apply a range of 0-16 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate a range of 0-10 mA of current. In at least one example, the pair of proximal electrode contacts comprises a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts comprises a first distal electrode contact and a second distal electrode contact, wherein the pair of middle electrode contacts comprises a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

[0094] In at least one example, the first arrangement of electrode contacts is arranged in mirrorsymmetry with the second arrangement of electrode contacts across the longitudinal axis. In at least one example, the first proximal electrode contact and the second proximal electrode contact are arranged in mirror- symmetry across the longitudinal axis, wherein the first middle electrode contact and the second middle electrode contact are arranged in mirror- symmetry across the longitudinal axis, and wherein the first distal electrode contact and the second distal electrode contact are arranged in mirror symmetry across the longitudinal axis.

[0095] In at least one example, the first proximal electrode contact spans a first range of degrees along a circumference of the inner surface of the tubular cuff body; the first distal electrode contact spans a second range of degrees along the circumference of the inner surface of the tubular' cuff body; the second proximal electrode contact spans a third range of degrees along the circumference of the inner surface of the tubular- cuff body; the second distal electrode contact spans a fourth range of degrees along the circumference of the inner surface of the tubular cuff body; the first middle electrode contact spans a fifth range of degrees along the circumference of the inner surface of the tubular cuff body; and the second middle electrode contact spans a sixth range of degrees along the circumference of the inner surface of the tubular cuff body, and wherein: the first range of degrees and the second range of degrees each overlap the fifth range of degrees and without overlapping each other, and the third range of degrees and the fourth range of degrees each overlap the sixth range of degrees and without overlapping each other.

[0096] In at least one example, the first range of degrees is contiguous with the second range of degrees, and the third range of degrees is contiguous with the fourth range of degrees. In at least one example, the first proximal electrode contact is longitudinally separated from the first middle electrode contact by a first spacing, the first distal electrode contact is longitudinally separated from the first middle electrode contact by a second spacing, the second proximal electrode contact is longitudinally separated from the second middle electrode contact by a third spacing, and the second distal electrode contact is longitudinally separated from the second middle electrode contact by a fourth spacing, and wherein the first spacing, the second spacing, the third spacing, and the fourth spacing are approximately equal to one another such that the first arrangement of electrode contacts is evenly spaced along the longitudinal axis and the second arrangement of electrode contacts is evenly spaced along the longitudinal axis.

[0097] In at least one example, the first proximal electrode contact and the second proximal electrode contact are located equidistant from and on opposite sides of the split, wherein the first middle electrode contact and the second middle electrode contact are located equidistant from and on opposite sides of the split, and wherein the first distal electrode contact and the second distal electrode contact are located equidistant from and on opposite sides of the split.

[0098] In at least one example, a length-to-width aspect ratio of the proximal and distal pairs of electrode contacts is approximately 3:1, and wherein a length-to-width aspect ratio of the pair of middle electrode contacts is approximately 2:1. In at least one example, each electrode contact of the pair of proximal electrode contacts, the pair of middle electrode contacts, and the pair of distal electrode contacts is shaped as quadrilateral comprising a rounded-corner rectangle. In at least one example, a length of each electrode contact of the proximal and distal pairs of electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is between approximately 2 - 3 mm, and wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm. In at least one example, each pathway of the plurality of conductor- access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof. In at least one example, the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and an outer surface of the tubular cuff body, and wherein an arc length of the conductor-access section along the second outer surface is equal to an arc length of the outer surface. In at least one example, a length of the tubular cuff body is approximately 14 mm.

[0099] In at least one example, the inner radial distance is approximately 0.5 mm and wherein the second outer radial distance is approximately 1 mm. In at least one example, a length of the tubular cuff body is in a range of 5- 15 mm. In at least one example, the inner radial distance is in a range of 0.5- 1.5 mm. In at least one example, the second outer radial distance is in a range of 1- 2.5 mm. In at least one example, the closure flap has an outer surface, and wherein the outer surface of the closure flap and the second outer surface of the tubular cuff body have an approximately constant radius relative to the longitudinal axis such that the nerve cuff is free of any radial protrusions from the outer surface of the closure flap and the second outer surface.

[0100] In at least one example, the outer surface of the closure flap has a third arc length and a circumference of the nerve cuff is approximately equal to a sum of the third arc length and the second arc length. In at least one example, the closure flap extends along an entire length of the nerve cuff from the proximal end of the tubular cuff body to the distal end of the tubular cuff body. In at least one example, at least one of the closure flap or the first outer surface of the first section of the tubular cuff body comprises or is coupled to a bonding material such that the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material. In at least one example, the closure flap is configured to be in physical contact with the first outer surface of the second section of the tubular cuff body when the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

[0101] In at least one example, the system includes at least one flexion zone. In at least one example, the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body. In at least one example, the at least one flexion zone comprises a groove in a wall of the tubular cuff body. In at least one example, the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards the second outer surface to form a flexion zone wall bounded by the second outer surface. Tn at least one example, the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body. In at least one example, the at least one flexion zone is positioned radially opposite the split.

[0102] In at least one example, the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split. In at least one example, the opening defined by the split in the tubular cuff body is characterized by a first width from the first outer surface of the first section to the first outer surface of the second section, and a second width from the inner surface of the first section to the inner surface of the second section. In at least one example, the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width. In at least one example, the nerve comprises a cervical phrenic nerve. In at least one example, the IPG is configured to control an anodecathode pair selection from the plurality of electrodes to selectively steer the stimulation current towards the motor fibers of the nerve and away from the sensory fibers of the nerve.

[0103] In at least one example, the IPG is configured to control the anode-cathode pair selection from the plurality of electrodes based on a user-selected anode-cathode pair selection. In at least one example, the IPG is configured to control the anode-cathode pair selection based on sensory feedback information indicative of a sensory response by the patient to the stimulation current. In at least one example, the sensory feedback information includes one or more of heart-rate information, skin-conductivity information, breathing-rate information, user-feedback information.

[0104] BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Various aspects of at least one embodiment are discussed below with reference to the accompanying figures, which may not be drawn to scale. The figures are included to provide an illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification, but are not intended as a definition of the limits of a particular embodiment. The drawings, together with the remainder of the specification, serve to explain principles and operations of the described and claimed aspects and embodiments. In the figures, each identical or substantially similar component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every figure. In the figures: FIG. 1 illustrates a block diagram of a disordered breathing therapy system according to an example;

[0106] FIG. 2 illustrates a block diagram of a medical device and computing device system according to an example;

[0107] FIG. 3 illustrates a side view of a lead according to an example;

[0108] FIG. 4 illustrates a block diagram of a nerve cuff according to an example;

[0109] FIG. 5 illustrates a perspective view of a nerve cuff according to one example;

[0110] FIGS. 6A, 6B, 6C, and 6D each illustrate a cross-section view of the nerve cuff of FIG. 5, with substantially similar views of the nerve cuff but different annotations for illustrative clarity, according to an example;

[0111] FIG. 6E illustrates a cross-section view of a nerve cuff according to another example;

[0112] FIGS. 6F and 6G illustrate cross-section views of a nerve cuff having an extended flap;

[0113] FIG. 7A illustrates a cross-section view of a nerve cuff according to another example;

[0114] FIG. 7B-1 illustrates a cross-section view of a nerve cuff according to another example;

[0115] FIG. 7B-2 illustrates a cross-section view of a nerve cuff according to another example;

[0116] FIG. 7C illustrates a cross-section view of a nerve cuff according to another example;

[0117] FIG. 7D illustrates a cross-section view of a nerve cuff according to another example;

[0118] FIG. 7E illustrates a cross-section view of a nerve cuff according to another example;

[0119] FIG. 7F illustrates a cross-section view of a nerve cuff according to another example;

[0120] FIG. 7G illustrates a cross-section view of a nerve cuff according to another example;

[0121] FIG. 7H illustrates a cross-section view of a nerve cuff according to another example;

[0122] FIG. 71 illustrates a cross-section view of a nerve cuff according to another example;

[0123] FIG. 8A illustrates a top view of a cuff body in an unrolled position according to an example;

[0124] FIG. 8B illustrates a top view of a cuff body with three electrode contacts in an unrolled position according to another example;

[0125] FIG. 9 illustrates a top view of a cuff body in an unrolled position with surgical sutures according to an example;

[0126] FIG. 10A illustrates a top view of a cuff body in an unrolled position according to another example; FIG. 10B illustrates a top view of a cuff body in an unrolled position according to another example;

[0127] FIG. IOC illustrates a top view of a cuff body in an unrolled position according to another example;

[0128] FIG. 10D illustrates a top view of a cuff body with three electrode contacts in an unrolled position according to another example;

[0129] FIG. HA illustrates a truncated top portion of a cuff body according to an example;

[0130] FIG. 1 IB illustrates a truncated top portion of a cuff body according to another example;

[0131] FIG. 11C illustrates a truncated top portion of a cuff body according to another example; FIG. 1 ID illustrates a truncated top portion of a cuff body according to another example; FIG. 1 IE illustrates a truncated bottom portion of a cuff body according to an example;

[0132] FIG. 1 IF illustrates a truncated bottom portion of a cuff body according to another example;

[0133] FIG. 11G illustrates a truncated bottom portion of a cuff body according to another example;

[0134] FIG. 11H illustrates a truncated bottom portion of a cuff body according to another example;

[0135] FIG. 12 illustrates a top-down view of a lead according to an example; and

[0136] FIGS. 13 and 14 illustrate a method of implant for a nerve cuff according to an example.

[0137] DETAILED DESCRIPTION

[0138] Sleep apnea is a type of disordered breathing that presents as a breathing-related sleep disorder. Sleep apnea exists in several forms, including central sleep apnea (CSA), obstructive sleep apnea (OSA), and other types of breathing disorders. CSA includes apnea events characterized by an ineffective, or decreased, respiratory effort. The decreased respiratory effort or drive may include an absent respiratory effort or drive. OSA includes apnea events characterized by an obstruction of airflow. An obstruction of airflow may result from a partial or complete obstruction of the airway resulting in a reduction in airflow relative to airflow without an obstruction.

[0139] In order to treat disordered breathing, a disordered-breathing-treatment system may provide electrical stimulation of various nerves. For example, electrical stimulation of the phrenic nerve, which stimulates diaphragm contraction, may improve respiration for patients exhibiting CSA. As another example, electrical stimulation of the hypoglossal nerve and / or the ansa ccrvicalis nerve, which stimulate muscular movement affecting airway patency may improve respiration for patients exhibiting OSA.

[0140] Electrical stimulation of various nerves may also treat conditions other than disordered breathing due to sleep apneas. The example devices described herein are not limited to treatment of disordered breathing due to sleep apneas as other implementations are contemplated. For example, these other implementations may include nerve stimulation to treat loss of diaphragm control due to paralysis or a neurodegenerative disease (for example, stimulation of the phrenic nerve), and nerve stimulation to wean patients from a ventilator (for example, stimulation of the phrenic nerve), to name a few examples not limiting of the disclosure.

[0141] Electrical stimulation may be delivered to a target nerve through devices such as a nerve cuff implanted around a target nerve. The nerve cuff includes electrodes and is surgically implanted so that the electrodes are in direct physical contact with the target nerve when the nerve cuff is positioned around the target nerve. The electrodes on the nerve cuff receive an electrical stimulation signal from a pulse generator. The nerve cuff may also be coupled to an electrical lead. The pulse generator may be implanted and physically coupled to the electrodes via the electrical leads. Alternatively or additionally, the pulse generator may be external and may wirelessly provide the generated stimulation pulse to the electrodes (for example, via one or more antennas, a magnetic field, and so forth) of the nerve cuff.

[0142] Examples of the disclosure include nerve cuffs. The nerve cuff places the electrodes in direct contact with the nerve and provides energy efficient stimulation, as the electrodes sit close to the nerve fibers. Proximity to the nerve may also result in increased battery life, as the desired therapy by electrical stimulation may be achieved at lower energy levels. Further, as discussed in more detail below, the positioning of the nerve cuff electrodes with respect to particular fibers in the nerve may enhance benefits of current steering.

[0143] Nerve cuffs discussed herein may be used in connection with various target nerves. For purposes of explanation, examples of the disclosure may be provided with respect to a phrenic nerve in the cervical region of a patient. However, in various examples, the principles of the disclosure are applicable to the phrenic nerve in the thoracic region and to nerves other than the phrenic nerve, such as a hypoglossal nerve, an ansa cervicalis nerve, a C12 group nerve, a CIO group nerve, a vagus nerve, and / or other nerves. Each of these target nerves may be characterized by a particular nerve diameter, a particular arrangement of nerve fibers, a threshold nerve activation energy, a compression tolerance, and / or other nerve characteristics. The cuff dimensions, geometry, compression characteristics, electrical characteristics, etc., may be designed specifically for use on a particular nerve in order for the cuff to function effectively on the nerve at the particular location on the nerve. Thus, the mere designation of an electrode arrangement as a “nerve cuff’ does not necessarily render nerve cuffs interchangeable.

[0144] The characteristics of any nerve may vary depending on the particular location in the body. For example, the phrenic nerve traverses the cervical and thoracic regions of the human body. The arrangement of nerve fibers in the phrenic nerve changes along this traversal. The motor fibers enable motor control signals from the brain to reach the muscle. The sensory nerve fibers enable pain or discomfort signals to reach the brain. Accordingly, it may be advantageous to preferentially stimulate the motor fibers and to reduce, minimize, or avoid stimulation of the sensory fibers.

[0145] In the thoracic region, the arrangement of motor nerve fibers and sensory nerve fibers of the phrenic nerve varies over the cross-section of the nerve; motor and sensory fibers are dispersed and intermixed across the nerve cross section. In contrast, in the cervical region, the motor nerve fibers and sensory nerve fibers of the phrenic nerve are arranged in groups along the length of the nerve. That is, motor nerve fibers are clustered together in one or more groups and sensory nerve fibers may be clustered together in one or more separate groups. These fibers are not dispersed and intermixed across the cross section, and the arrangement of fibers is not as highly variable along the length of the phrenic nerve in the cervical region as the arrangement of fibers is in the thoracic region. Thus, a nerve cuff as described herein may be advantageous in phrenic nerve applications because the circumferential position of electrodes applied to the phrenic nerve in the cervical region may effect preferential stimulation of motor nerve fibers in the cervical region of the phrenic nerve. For example, for a nerve cuff with electrodes arranged circumferentially, current traveling from one electrode to another across the nerve cross-section may preferentially stimulate motor nerve fibers based on the cross-sectional arrangement of the groups of motor nerve fibers and sensory nerve fibers.

[0146] Based on this nerve fiber arrangement, in some examples, current steering may be used to target the motor nerve fibers. For example, some nerve cuffs may include multiple electrodes. Because electrodes are positioned at different locations, a stimulation current passing between different anode-cathode pairs causes different areas of the nerve to he stimulated. Current may thus be steered to different electrodes to target different areas of the phrenic nerve. For example, current may be steered to different electrodes to target motor fibers while avoiding sensory fibers. Current steering therefore enables the nerve cuff to direct more, most, or all of a stimulation current to the motor nerve fibers instead of the sensory nerve fibers. Higher stimulation currents may therefore be used without causing a patient unnecessary pain or discomfort, because less (or no) stimulation is provided to the sensory nerve fibers.

[0147] After recovery from the surgical implant procedure, the various current steering patterns available can be tested with the patient fully awake and the physician may select the steering pattern that reduces, minimizes, or eliminates patient pain or discomfort. Thus, managing pain or discomfort with the nerve cuff electrode that enables steering requires adjustment of the programming of the pulse generator, but this pain or discomfort management does not require a change in the physical position of the electrodes. This may provide the benefit of an implant procedure with the patient fully sedated.

[0148] Because nerve cuffs are designed to hug a nerve in order to maintain positioning and for efficiency of stimulation delivery, they cannot be assumed to be interchangeable between nerves given the typical differences in nerve dimensions. Additionally, the ansa cervicalis may be a more robust nerve and able to tolerate higher compression forces without nerve damage than the phrenic nerve.

[0149] As additional considerations, the nerve cuffs described herein offer the advantage of having a relatively small physical size. The relatively small physical size is not merely a formfactor decision based on nerve geometry. Rather, in order to successfully reduce the size and scale of a nerve cuff and still retain optimized nerve compatibility and stimulation delivery characteristics, manufacturing methods such as molding, cutting, bonding, welding, lithography, coating, embedding, etc., require redevelopment. The smaller physical geometry may reduce the surgical opening required for implantation and reduces the extent of physical contact between the nerve cuff and the nerve. Physical contact with the nerve causes the nerve to be susceptible to trauma and thus minimal physical contact is advantageous. However, reducing the area of physical contact also reduces the surface area of the electrodes and thus must also be balanced with a need for biostability and sufficient current delivery. As discussed above, stimulating a phrenic nerve or upper airway nerve may cause muscular contractions. Such stimulation is a functional stimulation. This functional stimulation differs from non-functional stimulations that stimulate a nerve to affect a systemic bodily system. For example, non-functional stimulations of the vagus nerve may act on the parasympathetic nervous system to neurologically regulate conditions such as Parkinson’s disease, high blood pressure, or tremors without causing a functional change in a particular muscle.

[0150] As an additional consideration, in some cases, preferential stimulation of the sensory nerve fibers (that is, afferent axons) may be used in some patients in order to block or disrupt pain or discomfort signals as a way to reduce the pain or discomfort sensation of the patient. However, these stimulations are generally at a higher frequency and follow a different stimulus protocol from functional stimulations of the motor nerve fibers. Thus, stimulation of afferent axons to block or disrupt pain or discomfort signals is not equivalent to, nor interchangeable with, functional stimulation of efferent axons with selective steering to avoid the afferent axons.

[0151] FIG. 1 illustrates a block diagram of a disordered breathing therapy system 100 according to an example. A quantity of each component in FIG. 1 is an example only and other quantities of each component could be used. The disordered breathing therapy system 100 may be implemented in connection with a patient to treat disordered breathing that occurs while the patient is sleeping, such as one or more forms of sleep apnea. For example, the disordered breathing therapy system 100 may be implemented in connection with a patient experiencing CSA events, OSA events, other types of disordered breathing events and / or a combination of such events.

[0152] The disordered breathing therapy system 100 includes an implanted treatment system 10 and an external computing device 210, which is discussed in greater detail below with respect to FIG. 2. The implanted treatment system 10 includes an implantable device 12 (for example, an implantable pulse generator 12, or IPG 12), one or more stimulation leads 14, one or more controllers 16, and memory and / or storage 18 (or memory 18). Although the IPG 12 is illustrated as separate from the controller 16 for purposes of explanation, in some examples the controller 16 may be a component of the IPG 12. Furthermore, although shown as part of an implanted treatment system, the pulse generator 12, controller 16, and memory 18 may be components of an external system configured to wirelessly transmit electrical stimulation energy to the implanted nerve cuff. The TPG 12 is electrically coupled to the leads 14, and is communicatively and / or electrically coupled to the one or more controllers 16 (or may include the controllers 16). Each of the leads 14 may include or be coupled to one or more nerve cuffs having one or more electrodes in order to deliver electrical stimulation to the target nerve. The IPG 12 may generate an electrical stimulation signal (for example, based on control signals provided by the controllers 16) and deliver the electrical stimulation energy to the leads 14 to provide electrical stimulation to the target nerve via the nerve cuff electrodes. In some examples, the implanted treatment system 10 may include additional components (for example, sensors, additional leads, and so forth) which are omitted for brevity and explanation. In an implementation, the one or more stimulation leads 14 may include one or more transvenous leads.

[0153] The treatment system 10 is configured to be communicatively coupled to the computing system 210 via a wireless communication connection. For example, the controllers 16 may be communicatively coupled to the computing system 210. In various implementations, wireless communications may be exchanged pursuant to a short-range wireless communication protocol such as, for example, the Bluetooth® wireless communication protocol, or inductive telemetry, or another telemetry method. Examples of the computing system 210 are provided in more detail below.

[0154] As discussed in greater detail below, the controller 16 may control the IPG 12 to deliver electrical stimulation to the target nerve. For example, stimulation of the phrenic nerve (for example, stimulation of the right phrenic nerve and / or the left phrenic nerve) to produce rhythmic contractions of one hemidiaphragm innervated by the stimulated nerve. The consequent rhythmic lung inflations may synchronize the patient’s respiratory drive with the stimulation.

[0155] In various examples, the controllers 16 are configured to process information and control operation of the treatment system 10, such as by delivering and modifying the treatment (for example, a current pulse train). The controllers 16 may include one or more processors to execute instructions stored on one or more non-transitory computer-readable media. Accordingly, when the treatment system 10 is described as determining information or parameters, executing operations such as comparing values to thresholds, modifying parameters for electrical stimulation, sensing or obtaining parameters or information, and so forth, the controllers 16 may be performing these operations. Various controllers, such as the controller 16, may execute various operations discussed herein. The controller 16 may also execute one or more instructions stored on one or more non- transitory computer-readable media, which the controller 16 may include and / or be coupled to, which may result in manipulated data. The non-transitory computer-readable media may include memory and / or storage. In some examples, the controller 16 may include one or more processors or other types of controllers. In one example, the controller 16 is or includes at least one processor. In another example, the controller 16 performs at least a portion of the operations discussed above using an application- specific integrated circuit tailored to perform particular operations in addition to, or in lieu of, a processor. As illustrated by these examples, examples in accordance with the present disclosure may perform the operations described herein using many specific combinations of hardware and software and the disclosure is not limited to a particular combination of hardware and software components. Examples of the disclosure may include a computer-program product configured to execute methods, processes, and / or operations discussed above. The computer-program product may be, or include, one or more controllers and / or processors configured to execute instructions to perform methods, processes, and / or operations discussed herein.

[0156] In operation, an electrical stimulation signal (for example, an energy pulse train) generated by the IPG 12 travels along the lead 14 to a nerve cuff. The nerve cuff includes electrodes configured to deliver electrical stimulation to a target nerve. In some examples, the nerve cuff also includes one or more electrodes configured as sensors, such as an electromyography (EMG) sensor, an accelerometer, an acoustic sensor, and so forth. These sensors may sense, and generate signals indicative of, a physiological or physical parameter of the patient, such as a respiratory parameter. For example, the EMG sensor may sense and generate signals indicative of a muscular response to the electrical stimulation, the accelerometer may sense and generate signals indicative of motion and / or a position of one or more parts of a patient’s body, the acoustic sensor may sense and generate signals indicative of vibrational occurrences such as snoring, and so forth.

[0157] An energy pulse train provided for a period of time on an electrode results in an electric charge. The electrode(s) provides this electric charge to the nerve or other target tissue. Various parameters of the energy pulse train determine the total electric charge or stimulation energy applied to the target tissue. The pulse train may include a plurality of individual pulses with each pulse train envelope. The IPG 12 may modulate these parameters to control the stimulation energy provided to the nerve. These parameters may include one or more of a minimum treatment energy, a maximum treatment energy, a number of individual pulses within a pulse train, a frequency of individual pulses, a width of the individual pulses, an individual pulse amplitude, a maximum individual pulse amplitude, a stimulation current, a stimulation voltage, a stimulation polarity (for example, monophasic or biphasic), stimulation energy ramps, and so forth. Although examples herein may refer to stimulation current for simplicity, control of the stimulation energy by the IPG 12 is not limited to stimulation current control and may include one or more parameters of the energy pulse train. The electric charge activates the fibers (that is, generates an action potential) causing a functional response by the nerve. More energy (for example, higher stimulation current) means more fibers are activated, resulting in a larger functional response. Less energy (for example, lower stimulation current) means fewer fibers are activated, resulting in a smaller functional response.

[0158] For a particular functional response, such as the inducement of the contraction of a muscle (for example, the diaphragm), a minimum threshold charge may be required. The strength of the functional response (for example, the strength and / or extent of a muscular contraction needed to achieve a desired effect on respiration) determines the minimum threshold charge. In order to provide a range of functional responses (for example, a range of strengths and / or extents of muscular contractions to create a range of effects on respiration), a device, such as the IPG 12, may be configured to provide current and / or current pulse trains to satisfy various thresholds. For example, there may be weak, medium, and strong thresholds to describe a range of functional responses.

[0159] When combined with a nerve cuff that enables current steering, as described herein, the IPG 12 may select particular electrodes as anode-cathode pairs and apply a potential difference across the selected pair to generate and selectively steer a stimulation current or stimulation field. One or more first electrode contacts may serve as cathodic contacts and one or more second electrode contacts may serve as anodic contacts. Thus, the anode-cathode pair may include two or more electrode contacts. In some examples, the IPG 12 may select the electrode contacts by controlling potential differences and / or one or more switching devices associated with the various electrode contacts. The IPG 12 may select different anode-cathode pairs to selectively steer the stimulation current to the nerve encircled by the nerve cuff. Each anode-cathode pair may correspond to a different path for stimulation current. The path of the stimulation current between each anodc-cathodc pair may be referred to as a current vector. The IPG 12 may select a desired current vector by providing electrical signals to a corresponding anode-cathode pair.

[0160] The IPG 12 may include electrical circuitry components and a battery. The IPG 12 receives programmable operating parameters via software and / or firmware downloaded to the IPG 12 via wired or wireless communications. In an implementation, the external computing device 210 may generate the programmable operating parameters, for example, based at least in part on user input to the external computing device 210. These programmable operating parameters may include steering parameters for the nerve cuff. For an implanted IPG, the electrical circuitry components and battery may be enclosed in a hermetically sealed casing to protect these components from the body environment.

[0161] The implanted IPG may further include a header disposed on the casing. The header may be a structural component of the implanted IPG that provides one or more receptacles, or connector ports, configured to receive respective connector assemblies for leads connected to the nerve cuff. Each lead may couple with one or more connector ports. The header thus provides paths to electrically and mechanically couple the leads and the nerve cuff electrodes to the enclosed components of the implanted IPG 12 without compromising the hermetic seal. The connector ports may be configured and / or re-configured as sensor ports, stimulation ports, sensor-and-stimulation ports, and so forth according to programmed configuration settings provided to the IPG 12 through the firmware and / or software. The firmware and / or software may configure the connector ports to control and / or designate various electrodes as anodes, cathodes, and / or anode-cathode pairs.

[0162] FIG. 3 illustrates a side view of a lead 300 according to an example. The lead 300 may be an example of one of the leads 14. The lead 300 includes a nerve cuff 302, distal bifurcated conductors 304, a distal bifurcation 306, a middle conductor 308, a proximal bifurcation 310, and proximal bifurcated conductors 312. The conductors 304, 308, and 312 may be coiled conductors (for example, co-axial or co-radial). The lead 300 may have a total length L. In some examples, L may be approximately 45 cm. In some examples, L may be between approximately 20-70 cm or 30-60 cm or less than or equal to 30, 35, 40, 45, 50, 55, or 60 cm. The elements 304, 306, 310, and 312 are described herein as “bifurcated” or “bifurcations” as examples only and in various implementations of the lead 300 one or more of these elements may be singular, bifurcated, trifurcated, quadrifurcated, and so forth depending on the specifics of a particular lead implementation .

[0163] For purposes of discussion, the portions of the lead 300 may include a proximal portion 314, a middle portion 316, and a distal portion 318. The lead 300 is bound by the proximal end 320 and the distal end 322 and extends between these two points. The proximal portion 314 extends from the proximal end 320 of the lead 300 — which may be the point on the proximal bifurcated conductors 312 which couples to the IPG 12 (and is thus closest, or most proximal to, the IPG 12) to the connection between the proximal bifurcation 310 and the middle conductor 308. The proximal portion 314 therefore includes the proximal bifurcation 310, the proximal bifurcated conductors 312, and the proximal end 320. The middle portion 316 extends from the distal bifurcation 306 to the proximal bifurcation 310 and may include the middle conductor 308.

[0164] The distal portion 318 extends from the connection between the distal bifurcation 306 and the middle conductor 308 to the distal end 322 of the lead 300. The distal end 322 of the lead 300 may be a point on the nerve cuff 302 which is farthest along the lead 300 from the proximal end 320. The distal portion 318 therefore includes the distal bifurcation 306, the distal bifurcated conductors 304, the nerve cuff 302, and the distal end 322. The distal portion 318 of the lead 300 therefore includes all components of the nerve cuff 302, such as the electrodes of the nerve cuff 302.

[0165] The distal bifurcated conductors 304 may include two groups of conductors, each group including one or more conductors depending on the number of electrodes such that each conductor is electrically coupled to a respective electrode contact of the nerve cuff 302.

[0166] In some examples, each of the conductors may be configured to electrically and / or physically couple to the IPG 12 to transmit electrical signals between the IPG 12 and the nerve cuff 302. In some examples, one or more of the conductors may bidirectionally transmit electrical signals between the IPG 12 and the nerve cuff 302.

[0167] Accordingly, the lead 300 conducts electrical signals between the IPG 12 and the nerve cuff 302. The nerve cuff 302 is configured to be physically coupled to a target nerve. For example, the nerve cuff 302 may be implanted by an implanter (for example, a surgeon, an electrophysiologist, a cardiac specialist, an ear / nose / throat specialist, a different medical practitioner, a combination thereof, and so forth) around the target nerve. As noted above, the proximal bifurcated conductors 312 are configured to be electrically coupled to a pulse generator, such as the IPG 12. Stimulation signals generated by the IPG 12 may be provided to the nerve cuff 302 to capture the target nerve (for example, to stimulate the target nerve to produce a desired functional response, such as stimulating the phrenic nerve to cause the diaphragm to contract).

[0168] As noted above, in various examples, stimulation signals destined for the nerve cuff 302 are received from the IPG 12 at the proximal bifurcated conductors 312. Each of the bifurcated conductors 312 couples with terminal pins that electrically couple to the IPG 12. The stimulation signals are provided to the proximal bifurcation 310, which joins the two proximal bifurcated conductors 312 into a single housing of the middle conductor 308. Whereas the proximal bifurcated conductors 312 may be thicker and more durable conductors, the middle conductor 308 may be a thin and flexible conductor which is easily maneuvered by surgeons during implantation. When the middle conductor 308 reaches the distal bifurcation 306, the middle conductor 308 is again bifurcated into the two distal bifurcated conductors 304. The distal bifurcated conductors 304 are coupled to the nerve cuff 302. Accordingly, a current pulse train provided by the IPG 12 is provided first to the proximal bifurcated conductors 312, and travels through the proximal bifurcation 310, the middle conductor 308, the distal bifurcation 306, and the distal bifurcated conductors 304 before reaching the nerve cuff 302.

[0169] As discussed in greater detail below, the distal bifurcated conductors 304 may be electrically coupled to electrodes in the nerve cuff 302. In various examples, a current pulse train provided by the IPG 12 to the nerve cuff 302 may specifically be provided to one or more of the electrodes of the nerve cuff 302. Different electrodes may be activated by providing a current pulse train to desired electrodes. As discussed in greater detail below, this approach of directing a current pulse train to desired electrodes may be referred to as current steering. Implementing current steering enables the nerve cuff 302 to stimulate different regions of a target nerve by adjusting the current vector between electrodes. The ability to stimulate different regions of a target nerve enables the treatment system 10 to deliver more of the electrical stimulation to motor nerve fibers (for example, to maximize diaphragm modulation) and less of the electrical stimulation to sensory nerve fibers (for example, to minimize or eliminate pain or discomfort).

[0170] In some implementations, the lead 300 (and / or the lead 1200 as shown in FIG. 12) may optionally include one or more additional leads 399. The additional leads 399 may branch off at the bifurcation 306 (or along the lead 1200 at one or more of the wrappings or exterior casings 1206). The additional leads 399 may include sensor electrodes 398, such as, for example, but not limited to, electromyography sensors, acceleration or motion sensors, acoustic sensors, pressure sensors, impedance sensors, etc.

[0171] FIG. 4 illustrates a block diagram of a nerve cuff 400 according to an example. The nerve cuff 302 may be an example embodiment of the nerve cuff 400. The nerve cuff 400 includes one or more electrode contacts 402, one or more closure flaps 404, and a cuff body 406. In some examples, the cuff body 406 may be a tubular cuff body. The cuff body 406 includes at least one split 410.

[0172] Optionally, the cuff body 406 includes at least one flexion zone 408. Although the examples herein illustrate one flexion zone 408, the nerve cuffs may include two or more flexion zones 408. Multiple flexion zones may enable the nerve cuff to unfold in a flatter profile than only one flexion zone which may be advantageous for enabling wrapping of the cuff around the nerve during the implant procedure. Additionally, including multiple flexion zones may reduce the radial force on the nerve thereby reducing the risk of nerve trauma as compared with a single flexion zone or no flexion zone. The location of one or more flexion zones may also vary relative to the electrodes. In an example, the flexion zone 408 may be a thinner walled area of the cuff 400 that can flex more readily than surrounding thicker walled areas. Additionally or alternatively, the flexion zone 408 may include holes or perforations that increase flexibility and reduce resistance to bending. The at least one flexion zone 408 may extend longitudinally along an entire length of the tubular cuff body 406 and may extend radially outward from the inner surface of the tubular cuff body 406 towards an outer surface of the tubular cuff body 406 to form a flexion zone wall bounded by the outer surface.

[0173] The electrode contacts 402 may be electrically and / or physically coupled to the IPG 12 via conductors 412. The conductors 412 may pass between the IPG 12 and the nerve cuff 400 via lead cabling, such as within the conductors 304, 308, 312. The IPG 12 may provide an electrical stimulation signal to the electrode contacts 402 via the conductors 412 to stimulate a target nerve after the nerve cuff 400 is implanted. For the nerve cuff examples described herein, the electrode contacts 402 may be configured to selectively steer stimulation of the target nerve or may be configured for non-selective stimulation of the target nerve. In various embodiments, the target nerve may be a phrenic nerve, a hypoglossal nerve, or the ansa cervicalis. The arrangement of the conductors and the electrode contacts 402 with regard to electrical coupling and electrical isolation may determine whether a particular nerve cuff provides selective or non-selective stimulation.

[0174] An implanter may surgically implant the nerve cuff 400. To aid in explanation of the surgical attachment of the nerve cuff 400 to a target nerve, FIG. 5 illustrates a perspective view of a nerve cuff 500 according to one example. The nerve cuff 500 illustrated in FIG. 5 may be one example implementation of the nerve cuff 400. Accordingly, components of the nerve cuff 500 representing example implementations of components of the nerve cuff 400 are labeled accordingly. However, it is understood that the nerve cuff 400, and example components of the nerve cuff 400, may be implemented differently than what is shown in the non-limiting examples depicting the nerve cuff 500.

[0175] In FIG. 5, the nerve cuff 500 is in a normal equilibrium position and depicts a portion of one of the electrode contacts 402, the closure flap 404, the cuff body 406, the flexion zone 408, and the split 410. The nerve cuff 500 includes a proximal end 504 (which may, for example, be coupled to the distal bifurcated conductors 304) and a distal end 506 (which may, for example, be the same point or location as the distal end 322 of the lead 300). The nerve cuff 500 extends along a longitudinal axis 508, which extends from the proximal end 504 to the distal end 506. Accordingly, the proximal end 504 may be located at a first location along the longitudinal axis 508 and the distal end 506 may be located at a second location along the longitudinal axis 508. The flap 404 extends along the entire length of the cuff 500 from the proximal end 504 to the distal end 506. In an implementation, the flap 404 may have a lower durometer measurement, or hardness, than the cuff body 406. For example, the flap durometer measurement, or hardness, may be 10-30% lower than the cuff durometer measurement, or hardness.

[0176] As illustrated in FIG. 5, the nerve cuff 500, and examples thereof, may be a three- electrode-contact cuff 598 or a six-electrode-contact cuff 599. As described herein, the number of electrode contacts may vary according to a target nerve based on a size and / or geometry of the nerve and / or the electrostimulation properties of the nerve. For example, the three-electrode- contact cuff 598 may be a smaller inner diameter cuff (e.g., approximately 1 mm) for use on the ansa cervicalis. As another example, the six-electrode-contact cuff 599 may be larger inner diameter cuff (e.g., approximately 2 mm) for use on a phrenic nerve or a hypoglossal nerve. Certain aspects of the nerve cuff 500 may be omitted from FIG. 5 for clarity of illustration. For example, as discussed below with respect to FIG. 6A, the cuff body 406 may include conductor access pathways which are omitted from FIG. 5 for purposes of clarity.

[0177] To implant the nerve cuff 500, a patient may first be sedated. An implanter may then form a small surgical opening in a desired area. Although the procedures provided herein refer to the phrenic nerve as an example, a same or similar procedure may be used to implant the nerve cuff 500 on a different target nerve. For example, if a target nerve is the phrenic nerve in the cervical area of the patient’s neck, the implanter may make a small incision in the cervical area. In some examples, the surgical opening may be small, such as on the order of 2 - 4 cm to accommodate the relatively small cuff size as described herein. The cuff size is not merely a matter of form factor but rather depends on one or more of the implantation site, the type of stimulation (for example, nerve stimulation or cell stimulation), and the electrode size with regard to balancing biostability and a desired stimulation response based on factors including but not limited to amount of charge delivered per pulse, pulse rate, pulse shape, and so forth. As an example, a cuff used on the carotid artery to stimulate the carotid body for treatment of refractory hypertension may require a 4 - 6 mm diameter as opposed to the smaller diameter nerve cuffs described herein.

[0178] The surgeon may then select a location along the target nerve to couple the nerve cuff 500. For the phrenic nerve, the implanter may select a location that yields higher degrees of diaphragm modulation when the phrenic nerve is stimulated. For example, the implanter may use a small probe to apply a stimulation signal along the phrenic nerve. As the implanter applies the stimulation signal, the implanter may monitor diaphragm response to the stimulation. The surgeon may attempt to identify an area along the length of the phrenic nerve and / or around the circumference of the phrenic nerve (for example, based on the translative and rotative adjustments of the nerve cuff) that, when stimulated, leads to higher levels of diaphragm modulation. Once the implanter has identified the location along the phrenic nerve to couple the nerve cuff 500, the implanter begins to attach the nerve cuff 500 to the phrenic nerve.

[0179] To attach the nerve cuff 500 to the target nerve, the implanter may first pull aside the closure flap 404. As illustrated in FIG. 5, the closure flap 404 covers the split 410. Pulling the flap 404 away therefore exposes the split 410. The split 410 defines an opening in the cuff body 406 to allow a nerve to pass into the cuff body 406. In various examples, as discussed below, the split 410 may be a slit or a notch and may exhibit various shapes and geometries. The split 410 may extend along the cuff body 406 along a split axis 510, which is parallel to the longitudinal axis 508. Although the flap 404 may obscure at least part of the split 410, in some examples the split 410 extends from the proximal end 504 of the cuff body 406 to the distal end 506 of the cuff body 406 along the split axis 510. Once the closure flap 404 is pulled aside to reveal the split 410, the implanter may place the nerve cuff 500 over the target nerve by passing the target nerve through the split 410. The opening defined by the split 410 may be characterized by a first width from an outer surface of a first section of the cuff body 406 (as discussed below with respect to the non-limiting example of the first section 604) to an outer surface of a second section of the cuff body 406 (as discussed below with respect to the non-limiting example of the second section 606), and a second width from an inner surface of the first section to an inner surface of the second section.

[0180] To aid in passing the target nerve through the split 410, the implanter may rotate the nerve cuff 500 about the longitudinal axis 508. The nerve cuff 500 may have a clamshell-like configuration such that the split 410 is expanded by rotating the nerve cuff 500 about the flexion zone 408. In an example, the flexion zone may extend along the cuff body 406 parallel to the longitudinal axis 508 of the nerve cuff 500. As discussed below, the flexion zone 408 may improve or enhance the flexibility of the cuff body 406 by providing a thinner wall thickness according to various geometries. The flexion zone 408 may improve or enhance the flexibility of the cuff body 406 while still enabling the cuff body 406 to close around the nerve and remain in position without sliding or reopening, for example, while maintaining sufficient contact with the nerve to allow efficacious nerve stimulation but without causing nerve trauma due to over compression. By expanding the split 410, the phrenic nerve can be passed through the expanded split 410 more easily. The cuff body 406 may exert a restoring force to return the nerve cuff 500 to its normal, equilibrium position (for example, illustrated in FIG. 5) once the implanter stops holding the nerve cuff 500 open.

[0181] Once the target nerve is passed through the expanded split 410 (or the nerve cuff 500 is passed over the target nerve) and sits within the nerve cuff 500, the implanter may stop holding the nerve cuff 500 in its expanded, rotated-out position. When the implanter releases the force holding the nerve cuff 500 open, the nerve cuff 500 may return to its normal equilibrium position (for example, illustrated in FIG. 5), at which point the nerve cuff 500 encircles the nerve. That is, the cuff body 406 may exert a restoring force to return the nerve cuff 500 to its normal equilibrium position in which the split 410 is contracted relative to the expanded position.

[0182] Because the split 410 is contracted back to its original position, a chance of the target nerve accidentally slipping out of the now-smaller or closed split 410 may be reduced. The implanter may then restore the closure flap 404 to its original position overlaying the split 410, thereby covering the split 410. This original position of the closure flap 404, in which the flap 404 overlays and covers the split 410 as illustrated in FIG. 5, may be referred to as a closed flap position of the flap 404.

[0183] Accordingly, the nerve cuff 500 may be implanted in a patient by affixing the nerve cuff 500 to a desired location of a target nerve. Medical personnel (for example, the patient’s doctor[s]) may then wait until the patient’s surgical opening has healed (for example, over the course of approximately 4 - 6 weeks). Once the patient’s surgical opening and / or other attendant physical damage has healed, medical personnel may utilize the external computing device 210 to calibrate and / or program the IPG 12 to deliver electrical stimulation via the implanted nerve cuff 500. For example, firmware and / or software downloaded to the IPG 12 before or after implant may program the IPG 12. The IPG 12 may include at least one processor, at least one memory, and at least one communications interface collectively configured to receive, store, and execute the firmware and / or software to implement configuration settings for hardware and / or electrical stimulation parameters.

[0184] As noted above, the IPG 12 may deliver electrical stimulation signals to the nerve cuff 500 via the conductors 412. The conductors 412 may include the conductors discussed above as being housed by the conductors 304, 308, 312. In various examples, a one-to-one relationship may exist between the electrode contacts 402 and the conductors 412. For example, if the electrode contacts 402 include six electrode contacts, the conductors 412 may include six conductors each coupled between a respective electrode contact and the IPG 12.

[0185] As discussed above, two or more electrode contacts of the electrode contacts 402 may be electrically coupled to one another. For example, each of the two or more electrode contacts may be coupled to a respective conductor of the conductors 412. The two or more conductors may be electrically coupled to one another upstream of the nerve cuff 500, such as within the distal bifurcation 306. That is, the distal bifurcation 306 may house a single conductor that branches into two separate (but electrically coupled) conductors, each of which is routed to a respective electrode contact.

[0186] In such a situation, because the two electrode contacts are electrically coupled to one another in a short-circuit configuration, the two electrode contacts may be considered to be electrically configured as a single electrode. In various examples, therefore, the two electrode contacts may be considered to be physically configured or arranged as a pair of electrode contacts (that is, the pair of electrode contacts are physically separated from one another) and electrically configured as a single electrode (that is, the pair of electrode contacts are electrically coupled to one another in a short-circuit configuration). In some examples, at least one single electrode contact of the electrode contacts 402 is not electrically coupled to another electrode contact in a short-circuit configuration. Thus, nerve cuff 500 may include at least one electrode that includes a single one of the physical electrode contacts 402, and / or at least one electrode that includes two or more of the physical electrode contacts 402.

[0187] In various examples, therefore, the IPG 12 may deliver electrical stimulation to a target nerve by providing a stimulation signal (for example, a current pulse train) to the electrode contacts 402 via the conductors 412. Delivery of the stimulation signal to at least one of the electrode contacts 402 may cause a current to pass from at least one of the electrode contacts 402 (for example, a cathodic contact) to at least one other contact of the electrode contacts 402 (for example, an anodic contact). This current may stimulate a target nerve, such as by stimulating motor nerve fibers of a phrenic nerve of a patient to modulate the patient’s diaphragm. Different electrode contacts of the electrode contacts 402 may be activated to selectively steer current to a desired path. Such a desired path may include, for example, a path that maximizes diaphragm functional response while minimizing pain or discomfort sensations.

[0188] Example embodiments of the nerve cuff 400, and similarly the nerve cuff 500, and particularly aspects of the closure flap 404 and cuff body 406, will now be discussed with respect to FIGS. 6A-6G. Various other implementations of the nerve cuff 400 are within the scope of the disclosure.

[0189] FIGS. 6A-6D each illustrate a cross-section view of the nerve cuff 400. FIG. 6E illustrates an example of the nerve cuff 400 having three electrode contacts (e.g., the nerve cuff 598). FIG. 6F provides a nerve cuff 600 which is an example of the nerve cuff 400 with six electrode contacts (e.g., the nerve cuff 599) and a variation in a length of the closure flap 404. FIG. 6G provides a nerve cuff 621 which is an example of the nerve cuff 400 with three electrode contacts (c.g., the nerve cuff 598) and a variation in a length of the closure flap 404. FIGS. 6A-6D are substantially similar, with different annotations and separate figures provided simply for the illustrative clarity of the relevant reference numbers, lead lines, and so forth. As illustrated in FIGS. 6A-6G, the nerve cuff 400 may include various examples of the electrode contacts 402, the closure Hap 404, the cuff body 406, the flexion zone 408, and / or the split 410.

[0190] FIG. 6A, with further reference to FIG. 5, illustrates an imaginary line 602 bisecting the nerve cuff 400. The imaginary line 602 is perpendicular to the longitudinal axis 508, which extends into the page. The longitudinal axis 508 extends along the length of the tubular cuff body 406 down the center of the tubular cuff body 406. In various examples, FIGS. 6A-6G are illustrated from a perspective in which the proximal end 504 of the nerve cuff 500 is “behind” the perspective of the cross-sectional view, looking “towards” the distal end 506 of the nerve cuff 400.

[0191] The imaginary line 602 bisects the cuff body 406 along the flexion zone 408 and the split 410, and evenly bisects the flap 404 about the center of the flap 404. As discussed in greater detail below, the imaginary line 602 bisects the flexion zone 408 at a flexion zone wall 640.

[0192] The tubular cuff body 406 includes a first section 604 on a left-hand side of the imaginary line 602, and a second section 606 on a right-hand side of the imaginary line 602. Because the imaginary line 602 bisects the split 410, the split 410 may define an opening that divides the tubular cuff body 406 into the first section 604 and the second section 606. The cuff body 406 includes a conductor-access section 608, which includes a plurality of conductor- access pathways, or channels, 610 to receive respective conductors. The plurality of channels may be within the cuff body or along a surface of the cuff body and may include grooves along the cuff body surface, or combinations thereof. The conductor-access pathways may extend along the length of the cuff body and / or may wrap around all or a portion of a perimeter of the cuff body. The conductor-access section 608 may refer to a sector of the tubular cuff body 406 that is bound by an inner surface 614 and a second outer surface 618, discussed in greater detail below, and that extends along the second range of degrees 634.

[0193] In some examples, the plurality of channels 610 include a first group of channels in the first section 604 of the cuff body 406, and a second group of channels in the second section 606 of the cuff body 406. For example, the first and second groups may include the same number of channels (for example, three channels each) arranged in mirror-symmetry about the imaginary line 602. In other examples, the plurality of channels 610 may or may not be arranged in mirrorsymmetry, and / or may include an unequal number of channels in the two sections 604, 606, and / or may include channels in only one of the sections 604, 606. The examples of FIGS. 6A-6D are non-limiting and other examples are discussed with respect to FIGS. 7F-7I.

[0194] As illustrated at least in FIG. 6B, the tubular cuff body 406 includes an inner surface 614, a first outer surface 616, and a second outer surface 618. The flap 404 includes an inner surface 620 and an outer surface 622. The inner surface 614 of the cuff body 406 is located at an inner radial distance 624 from the longitudinal axis 508. In some examples, the inner radial distance 624 may be approximately constant along the longitudinal axis 508 (for example, the inner surface 614 may be smooth). The first outer surface 616 of the cuff body 406 is located at a first outer radial distance 626 from the longitudinal axis 508. The first outer radial distance 626 may be approximately constant along the longitudinal axis 508 (for example, the first outer surface 616 may be smooth). The second outer surface 618 of the cuff body 406 is located at a second outer radial distance 628 from the longitudinal axis 508, with the second outer radial distance 628 being greater than the first outer radial distance 626. The second outer radial distance 628 may be approximately constant along the longitudinal axis 508 (for example, the second outer surface 618 may be smooth). The inner surface 620 of the flap 404 is located at the first outer radial distance 626 from the longitudinal axis 508. The outer surface 622 of the flap 404 is located at the second outer radial distance 628 from the longitudinal axis.

[0195] A flap thickness 630 of the flap 404 may therefore be equal to a difference between the first outer radial distance 626 and the second outer radial distance 628. The cuff body 406 may not have a uniform thickness, because the two outer surfaces 616, 618 of the cuff body 406 are located at different radial distances 626, 628 from the inner surface 614. In particular, the first outer surface 616 of the cuff body 406 is characterized by a first arc length along a first range of degrees 632 about the longitudinal axis 508. The first arc length may be the length of the arc traversed by the first outer surface 616. For example, the first arc length may be equal to the first range of degrees 632 in radians multiplied by the first outer radial distance 626.

[0196] The flap 404 may also be characterized by a flap arc length along the first range of degrees 632. In some examples, the flap arc length may be equal to the first range of degrees 632 measured in radians multiplied by the second outer radial distance 628 (that is, an arc length of the outer surface 622 of the flap 404). In some examples, and as shown in FIGS. 6F and 6G, the flap 404 may also be characterized by a flap arc length along a range of degrees 693 where this range is inclusive of an extension into the area of the cuff 600 characterized by the second outer radial distance 628. In various implementations the range of degrees 693 may be between 180 and 360 degrees. In some examples, the range of degrees 693 may be between 220 and 320 degrees, may be less than 360 degrees, may be greater than 180 but less than 360 degrees, may be approximately 250, 275, 300, or 325 degrees, and so forth. A flap that extends beyond 180 degrees may provide a grab area 699 for use during surgical implant to pull the cuff 600 around the nerve with surgical tools. For example, the flap may extend 30-90 degrees beyond 180 degrees. However, a longer flap extension may increase the compressive force on the nerve and therefore a flap extension of less than 360 degrees may be desirable to balance the need for a grab area with a reduction in compressive force as the total length decreases. Further, the flap may include a tapered end 697 that has a radial cross-sectional width less than the flap thickness 630.

[0197] In various examples, the flap arc length may be equal to the first range of degrees 632 or 693 measured in radians multiplied by the first outer radial distance 626 (that is, an arc length of the inner surface 620 of the flap 404). In at least one example, the flap arc length may be measured based on a difference radial distance of the flap 404, such as from the center of the flap 404.

[0198] The flap arc length of the flap 404 may also be referred to as a flap length. For example, the flap arc length of the flap 404 that is determined by multiplying the first range of degrees 632 measured in radians by the first outer radial distance 626 may be referred to as an inner flap length. The flap arc length of the flap 404 that is determined by multiplying the first range of degrees 632 measured in radians by the second outer radial distance 628 may be referred to as an outer flap length.

[0199] The second outer surface 618 of the cuff body 406 is characterized by a second arc length along a second range of degrees 634 about the longitudinal axis 508. The second arc length may be the length of the arc traversed by the second outer surface 618. The second arc length may be calculated by multiplying the second range of degrees 634 by the second outer radial distance 628. The second arc length may be less than the first arc length. In various examples, both of the arc lengths are less than a circumference of the cuff body 406. For purposes of determining a circumference of the cuff body 406, a cuff radius 636 of the cuff body 406 (and of the nerve cuff 400) extends from the longitudinal axis 508 to the second outer surface 618 of the cuff body 406, and may therefore be equal to the second outer radial distance 628 in various examples.

[0200] Various values of the radial distances 624-628, 636 are within the scope of the disclosure. In some examples, the inner radial distance 624 is in the range of 0.3 - 2 mm. In some examples, the inner radial distance 624 may have an approximate value between 0.5 - 1.5 mm or approximately 0.5 mm, 1.0 mm, or 1.5 mm. In some examples, the first outer radial distance 626 is approximately 1-2 mm or approximately 1 mm, 1.5 mm, or 2 mm. In some examples, the second outer radial distance 628 is approximately 1.0 - 2.5 mm or 1.25 mm or 1.5 mm or 1.75 mm or 2.0 mm or 2.25 mm or 2.5 mm. A difference between the inner radial distance 624 and the second outer radial distance 628 defines a wall thickness of the nerve cuff 500. In various implementations, the wall thickness may stay constant around the nerve cuff 500 or may vary.

[0201] In one example, a cuff configured for use on the cervical phrenic nerve may have an inner radial distance 624 of approximately 0.7 - 1.5 mm or approximately 0.9 - 1.1 mm or approximately 1.0 mm. For example, the first outer radial distance 626 may be approximately 1.2 -2 mm or approximately 1.4 - 1.6 mm or approximately 1.5 mm. For example, the second outer radial distance 628 may be approximately 1.5-2.5 mm or 1.7-2.2 mm or approximately 2 mm. For example, the cuff for use on the cervical phrenic nerve may have an overall outer radial distance 636 of approximately 1.5-2.5 mm or approximately 1.7-2.2 mm or approximately 2 mm. The phrenic nerve typically presents with a cross-sectional radius of about 0.7- 1.3 mm. This radius has not been observed to vary significantly between the cervical and thoracic regions of this nerve.

[0202] In another example, a cuff configured for use on the ansa cervicalis may have an inner radial distance 624 of approximately 0.3-0.7 mm or approximately 0.4-0.6 mm or approximately 0.5 mm. As another example, the first outer radial distance 626 may be approximately 0.7- 1.3 mm or approximately 1 mm. For example, the second outer radial distance 628 may be approximately 0.9- 1.7 mm or 1.1 -1.5 mm or approximately 1.3 mm. For example, the cuff for use on the ansa cervicalis may have an overall outer radial distance 636 of approximately 0.9 - 1.7 mm or 1.1-1.5 mm or approximately 1.3 mm. The cuff may have a closure-flap thickness of approximately 0.2-0.3 mm. The ansa cervicalis has been observed to present with a cross- sectional radius of 0.3 - 0.7 mm. In one example, a cuff configured for use on the hypoglossal nerve may have an inner radial distance 624 of approximately 0.7-1.5 mm or approximately 0.9-1.1 mm or approximately 1.0 mm. For example, the first outer radial distance 626 may be approximately 1.2 -2 mm or approximately 1.4- 1.6 mm or approximately 1.5 mm. For example, the second outer radial distance 628 may be approximately 1.5-2.5 mm or 1.7-2.2 mm or approximately 2 mm. For example, the cuff for use on the hypoglossal nerve may have an overall outer radial distance 636 of approximately 1.5-2.5 mm or approximately 1.7-2.2 mm or approximately 2 mm. The hypoglossal nerve has been observed to present with approximately a 0.7-1.3 mm cross-sectional radius.

[0203] As discussed above, the flap thickness 630 may be equal to a difference between the second outer radial distance 628 and the first outer radial distance 626. The cuff radius 636 may be equal to a sum of the inner radial distance 624, a difference between the first outer radial distance 626 and the inner radial distance 624, and a difference between the second outer radial distance 628 and the first outer radial distance 626 (this difference being equal to the flap thickness 630).

[0204] An outer surface of the nerve cuff closure flap may be free of any radial protrusions from the outer surface thus providing an approximately constant outer diameter of the nerve cuff. For example, the outer surface 622 of the flap 404 may be at approximately the same radial distance from the longitudinal axis 508 as the second outer surface 618 (that is, the outer surface 622 of the flap 404 and the second outer surface 618 have an approximately constant radius relative to the longitudinal axis 508). Thus, the nerve cuff 400 is free of any radial protrusions (that is, protrusions off of the nerve cuff 400 away from the longitudinal axis 508) from the second outer surface 618 of the cuff body 406 and from the flap 404. Stated differently, the cuff radius 636 may be approximately constant and equal to the second outer radial distance 628 when the flap 404 is in the closed flap position. As a further example, the nerve cuff closure flap may wrap around the tubular cuff body and terminate in a tapered end (for example, the tapered end 697) along the tubular cuff body so as to provide an approximately constant outer radius or diameter (e.g., as discussed below with regard to FIGS. 6F and 6G). For example, the outer surface 622 may define the overall cuff radius 636 of the nerve cuff.

[0205] This approximately constant outer diameter (e.g., as illustrated in FIG. 6D by the a second circumferential trace 658 and a third circumferential trace 660, discussed in greater detail below)with an absence of radial protrusions may have several advantages. Radial protrusions may protrude into and irritate surrounding tissue. Moreover, such protrusion may limit the positioning of the cuff around the circumference of the nerve due to limitations imposed by surrounding tissues (for example, other nerves, bones, blood vessels, muscles, and so forth). Because the cuff 400 has a relatively smooth radial exterior, an implanter may rotate the nerve cuff 400 to a desired position around the circumference of the nerve without being limited by surrounding tissues that would be impinged upon by a substantial protrusion. Such impingement can lead to inflammation or imitation that may cause pain or discomfort and / or lead to undesired contact by the tissue on the target nerve that may interfere with treatment.

[0206] As illustrated in FIGS. 6A-6G, and as discussed further with regard to FIGS. 7A, 7C, 7D, and 7E, the flexion zone 408 may include a flexion zone wall 640 with a reduced thickness as compared to the rest of the cuff body 406. In this example, the flexion zone 408 may provide a hinging function by enabling rotation of the remainder of the cuff body 406 about the flexion zone wall 640. The flexion zone 408 may extend into the section of the cuff body 406 that sits within the second range of degrees 634, between the inner surface 614 and the second outer surface 618. The flexion zone 408 may extend longitudinally down the entire length of the cuff body 406. Although shown in FIGS. 6A-6G as a groove with a “V” shape, this is an example only and other shapes and geometries for the flexion zone are discussed below and are within the scope of the disclosure.

[0207] In the example of FIGS. 6A-6G, the flexion zone 408 is shown for example as a groove defined by the flexion zone wall 640 at the bottom of the groove, and by an opening on the inner surface 614 of the cuff body 406 at the top of the groove with a groove depth 642. The flexion zone 408 extends radially outward (that is, away from the longitudinal axis 508) from the inner surface 614 to the flexion zone wall 640. The flexion zone wall 640 extends radially outward (that is, away from the longitudinal axis 508) to the second outer surface 618 with a flexion zone-wall thickness 644. As discussed below, the flexion zone wall 640 may include perforations (not illustrated in FIGS. 6A-6G, but illustrated in FIG. 8 A) along the length of the flexion zone wall 640. The perforations may be slits, or openings, extending through the flexion zone wall 640. In other examples, such as the example of FIG. 8B, the flexion zone wall 640 may not include perforations. The perforations may further enhance or improve the flexibility of the nerve cuff. In some examples, the cuff body 406 may include one or more longitudinal sets of perforations at various locations. In the example of FIG. 8 A, a longitudinal set of perforations 914 is shown in the flexion zone wall 640. However, in some examples, the cuff body 406 may include perforations at a different and / or one or more additional locations in the cuff body 406.

[0208] As illustrated in FIG. 6B, the first outer surface 616 of the cuff body 406 is interrupted by an opening defined by the split 410, which is bisected by the imaginary line 602. In some examples, the opening defined by the split 410 is a “V”- or keystone-shaped opening characterized by a first width 646 at the top (that is, farther from the longitudinal axis 508) of the split 410 and a second width 648 at the bottom (that is, closer to the longitudinal axis 508) of the split 410. Although the first width 646 is illustrated as greater than the second width 648, this is an example only and in various implementations the first width 646 may be greater than, less than, or equal to the second width 648. The split 410 may have various geometries as discussed below with regard at least to one example discussed in FIG. 7A and the “V” or keystone-shaped opening is an example only and is not limiting of the disclosure. The first width 646 of the split 410 extends from the part of the first outer surface 616 that is in the first section 604 of the cuff body 406 to the part of the first outer surface 616 that is in the second section 606 of the cuff body 406. The second width 648 (or bottom width, or narrower width) of the split 410 extends from the part of the inner surface 614 that is in the first section 604 of the cuff body 406 to the part of the inner surface 614 that is in the second section 606 of the cuff body 406. As discussed in greater detail below, the split 410 may have a different shape and / or dimensions, or may be omitted entirely, in other examples. In various other examples, the first width 646 may be narrower than the second width 648, or the first width 646 may be equal to the second width 648, or the widths 646, 648 may be approximately zero such that the two sections 604, 606 are touching, and so forth. Additional examples of the split 410 are discussed below with respect to FIGS. 7A-7B-2.

[0209] The flexion zone 408 may be positioned radially opposite the split 410 about the longitudinal axis 508. Accordingly, the imaginary line 602 bisects both the flexion zone 408 and the split 410. Rotating or flexing the cuff body 406 about the flexion zone wall 640 with an axis- of-rotation parallel to the longitudinal axis 508 causes the split 410 to expand. In particular, flexing the nerve cuff 400 about the flexion zone wall 640 causes both the first width 646 and the second width 648 to expand, or widen. Widening the split 410 creates a larger gap for an implanter to pass a nerve through the split 410. An implanter may therefore flex the cuff body 406 about the flexion zone wall 640 during implantation of the nerve cuff 400 such that the cuff body 406 can be positioned around the nerve to encircle the nerve.

[0210] The inner surface 614 faces inwards towards the longitudinal axis 508 of the cuff body 406. When a nerve is inserted into the cuff body 406, the nerve sits along the longitudinal axis 508, encircled by the cuff body 406 such that the inner surface 614 faces towards the nerve. The first outer surface 616 and the second outer surface 618 of the cuff body 406 are each approximately concentric with each other and with the inner surface 614 of the cuff body 406, and face away from the nerve.

[0211] The first section 604 of the cuff body 406 is coupled to the flap 404 along a first contact area 650. In particular, the first outer surface 616 in the first section 604 may contact the inner surface 620 of the flap 404 (either directly or via a bonding material) along the first contact area 650. As discussed in greater detail below, the first contact area 650 may include or be coupled to a bonding material coupled to the first section 604 and the flap 404. For example, the bonding material may be molded directly onto or bonded to the inner surface 620 of the flap 404, or may be molded directly onto or bonded to the first outer surface 616 of the cuff body 406, or may be molded directly onto or bonded to both of the surfaces 616, 620. The bonding material bonds the first section 604 to the flap 404. The flap 404 may therefore be configured to be fixedly coupled to the first section 604 of the cuff body 406, for example, via the bonding material.

[0212] The second section 606 of the cuff body 406 is coupled to the flap 404 along a second contact area 652. In particular, the first outer surface 616 in the second section 606 may contact the inner surface 620 of the flap 404 along the second contact area 652. Whereas the first contact area 650 may include or be coupled to a bonding material, the second contact area 652 may not include or be coupled to a bonding material. The first outer surface 616 in the second section 606 may physically contact the inner surface 620 of the flap 404, but may move freely against the inner surface 620 of the flap 404. In this sense, the closure flap 404 may be considered to be physically and releasably coupled to the second section 606 of the tubular' cuff body 406 when the cuff body 406 is in the closed flap position.

[0213] The fixed coupling about the first contact area 650 and the releasable coupling about the second contact area 652 enables the nerve cuff 400 to expand and contract to accommodate nerve diameter changes, such as changes due to inflammation. As discussed herein, an excessive pressure on a nerve from a nerve cuff (for example a pressure greater than about 20 mmHg) may cause nerve trauma. However, insufficient pressure on the nerve reduces the efficacy of the stimulation, reduces the accuracy of the current steering, and / or may cause the nerve cuff to slip along the nerve to an undesired or less desirable position in terms of nerve stimulation. Thus, this ability of the nerve cuff to expand and contract in response to changes in the nerve is advantageous.

[0214] For example, consider a nerve encircled within the cuff body 406 along the longitudinal axis 508. The inner surface 614 of the cuff body 406 may be in physical contact with the nerve. If the nerve expands (for example, due to inflammation of the nerve), the nerve may apply an outward radial force on the inner surface 614. This outward radial force causes the cuff body 406 to expand radially, rotating about the flexion zone wall 640. Because the flap 404 is fixedly coupled to the first section 604 of the cuff body 406 at the first contact area 650, the flap 404 stays coupled to the cuff body 406 as the cuff body 406 expands. However, because the flap 404 is releasably coupled to the second section 606 of the cuff body 406 at the second contact area 652, the flap 404 simply slides along the cuff body 406 as the cuff body 406 expands. The cuff body 406 can therefore expand without the flap 404 becoming dislodged from the cuff body 406 (for example, because of the fixed coupling at the first contact area 650) and without the flap 404 holding the cuff body 406 closed (for example, because of the releasable coupling at the second contact area 652).

[0215] Examples of the nerve cuff 400 may be defined by various perimeters, circumferences, and arc lengths. FIG. 6C illustrates a perimeter trace 662 of the cuff body 406. FIG. 6D illustrates a first outer surface of the cuff body having a first arc length corresponding to a first circumferential trace 656. FIG. 6D further illustrates a second outer surface of the cuff body 406 having a second arc length corresponding to a second circumferential trace 658. The first circumferential trace 656 sweeps the first range of degrees 632 along the first outer radial distance 626. The second circumferential trace 658 sweeps the second range of degrees 634 along the second outer radial distance 628. An inner flap length of the closure flap(s) 404 corresponds approximately to the first circumferential trace 656. Further, the closure flap(s) 404 have a flap thickness approximately equal to a difference between the first outer radial distance 626 and the second outer radial distance 628 (as illustrated in FIG. 6B). An outer perimeter of the closure flap(s) 404 has a third arc length corresponding to a third circumferential trace 660. With the closure flap(s) 404 in a closed position, the outer perimeter of the closure flap(s) 404 is at the second outer radial distance 628 which is approximately equal to the cuff radius 636 (as illustrated in FIG. 6B). Therefore, a perimeter and circumference of the overall cuff 400 may be defined cumulatively by the third circumferential trace 660 and the second circumferential trace 658. As illustrated, the nerve cuff 400 may have an approximately constant cuff radius defining the perimeter and circumference corresponding to the third circumferential trace 660 and the second circumferential trace 658 cumulatively.

[0216] As discussed above, the nerve cuff 500 provides one example implementation of the nerve cuff 400. Aspects of the nerve cuff 400 may be implemented differently in other examples, including an example nerve cuff 601 in FIG. 6E, the example nerve cuff 600 in FIG. 6F, and the example nerve cuff 621 in FIG. 6G.

[0217] FIG. 6E illustrates a cross-section of a nerve cuff 601 according to another example. The nerve cuff 601 may include a protruding conductor-access section 609. The protruding conductor- access section 609 may limit the rotational positioning options for the nerve cuff 601. However, the protruding conductor- access section 609 may enable conductor access for a smaller diameter cuff, for example a cuff for a smaller target nerve such as the ansa cervicalis. For example, the smaller diameter cuff may be an example of the three-electrode-contact cuff 598 and may be approximately 1 mm in inner diameter. As another example, the larger diameter cuff may be an example of the six-electrode-contact cuff 599 and may be approximately 2 mm in inner diameter. The reduced diameter cuff may lack the necessary available real estate to accommodate the conductors without a protrusion. The nerve cuff 601 may also only have electrode contacts 402 on one side of the longitudinal axis (e.g., as shown for example in FIG. 8B), and therefore require fewer conductor channels 610. Although the flexion zone 408 and the split 410 are shown in a particular circumferential location relative to the electrodes 402 and to each other, this is an example only and not limiting of the disclosure. Various circumferential locations of the flexion zone 408 and the split 410 relative to the electrodes 402 and / or relative to one another are within the scope of the disclosure.

[0218] FIG. 6F illustrates a cross-section of a nerve cuff 600 according to another example. In some examples, the flap 404 may have an approximately constant thickness. For example, as discussed in connection with FIG. 6B, the nerve cuff 500 may be characterized by the approximately constant flap thickness 630. As discussed above, the flap thickness 630 may be determined based on a difference between the second outer radial distance 628 and the first outer radial distance 626, each of which is approximately constant.

[0219] In other examples, such as the example of FIG. 6F, the flap 404 may have a variable thickness. For example, while the second outer radial distance 628 may remain approximately constant, the first outer radial distance 626 (that is, the distance between the axis of the cuff 600 and the inner surface of the flap 404) may vary. The flap thickness may thus vary based on the varying difference between the radial distance 626, 628. In particular, while the flap thickness may remain approximately constant over the range of degrees 693, the flap thickness may decrease while moving counterclockwise around a second range of degrees 694. Accordingly, the flap 404 includes the tapered end 697 which tapers across the second range of degrees 694.

[0220] In various examples, the flap 404 may extend around the entire circumference of the cuff 600, and the ranges of degrees 693, 694 may collectively add to 360 degrees (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 also touches the “beginning” of the flap 404 at the “0, 360 degrees” label). In other examples, the flap 404 may extend around only a portion of the entire circumference of the cuff 600, and the ranges of degrees 693, 694 may collectively add up to less than 360 degrees. For example, FIG. 6G may provide an example in which the flap 404 extends around only a portion of the entire circumference of a cuff despite having a tapered end. In at least one example, the flap 404 may at least partially overlap itself, and the ranges of degrees 693, 94 may collectively add up to more than 360 degrees.

[0221] In at least one example, the range of degrees 693 may be greater than 180 degrees and less than 360 degrees, and the second range of degrees 694 may be less than 180 degrees. In various examples, the ranges of degrees 693, 694 may add up to less than 360 degrees and the tapered end 697 may end before covering at least a portion of the conductor access region 608 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 falls clockwise of the entire conductor access region 608), or may end before covering the entirety of one or more conductor access regions 608 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 falls clockwise of at least a portion of at least one conductor access region 608), or may end before covering at least a portion of the flexion zone 408 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 falls clockwise of the entirety of the flexion zone 408), or may end before covering all of the flexion zone 408 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 falls clockwise of at least a portion of the flexion zone 408), or may end proximate the flexion zone 408 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 at least partially intersects the flexion zone 408), or may end after covering all of the split 410 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 falls counterclockwise of the entirety of the split 410, including examples in which at least a portion of, and in which none of, the tapered end 697 at least partially overlaps the split 410), or may end before, after, or proximate the midpoint of the flexion zone 408 (for example, such that an imaginary line drawn from the axis of the cuff 600 to the end of the tapered end 697 falls clockwise of, counterclockwise of, or on, respectively, the midpoint of the flexion zone 408) or combinations of the foregoing, and so forth. Accordingly, in various examples the closure flap 404 may extend along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to, prior to, or after, a mid- line of the flexion zone 408.

[0222] In at least some examples, the range of degrees 693 may be greater than 180 degrees. In at least some examples, the range of degrees 693 may be less than or equal to 270 degrees. In at least some examples, the range of degrees 693 may be approximately (for example + / - 0.001 degrees, 0.01 degrees, 0.1 degrees, 1 degree, 1.5 degrees, 3 degrees, and so forth) 270 degrees or another approximate degree, such as an approximate degree between 180 and 360 degrees. Similarly, in at least some examples, the second range of degrees 694 may be less than 180 degrees. In at least some examples, the second range of degrees 694 may be greater than or equal to 90 degrees. In at least some examples, the second range of degrees 694 may be approximately (for example + / - 0.001 degrees, 0.01 degrees, 0.1 degrees, 1 degree, 1.5 degrees, 3 degrees, and so forth) 90 degrees or another approximate degree, such as an approximate degree between 0 degrees and 180 degrees.

[0223] In some examples, the tapered end 697 may taper at a constant rate over the second range of degrees 694. In other examples, the tapered end 697 may taper at a variable rate over the second range of degrees 694. For example, the tapered end 697 may taper gradually (that is, the thickness may decrease more slowly) while initially moving counterclockwise around the second range of degrees 694, but may taper more quickly (that is, the thickness may decrease more quickly) at the end of the tapered end 697. Tn other examples, the tapered end 697 may taper more quickly while initially moving counterclockwise around the second range of degrees 694, and may taper more slowly at the end of the tapered end 697.

[0224] In some examples, the cuff 600 includes electrode contacts 402 disposed on both sides of the flexion zone 408 and split 410. For example, the cuff 600 may be an example of the six- electrode-contact cuff 599.

[0225] FIG. 6G illustrates a cross-section of a nerve cuff 601 according to another example. Similar to the nerve cuff 600, the nerve cuff 601 may include a flap 404 having a variable thickness with a tapered end 697. Similar to the nerve cuff 600, the nerve cuff 601 may include the flap 404 having a constant thickness over the range of degrees 693, and a variable thickness over a second range of degrees 695, similar to the second range of degrees 694. Accordingly, a description of the variable-thickness flap 404 is not repeated for purposes of brevity.

[0226] Furthermore, the nerve cuff 601 includes a protruding conductor- access section 609, similar to the protruding conductor-access section 609 discussed above with respect to FIG. 6E. In at least one example, a sum of the ranges of degrees 693, 695 may be less than 360 degrees. A remaining circumference of the cuff 601 may span a third range of degrees 696. The ranges of degrees 693, 695, 696 may collectively add to 360 degrees. The third range of degrees 696 may provide a region in which the conductor-access section 609 can be implemented. As discussed above, the protruding conductor-access section 609 may enable conductor access for a smaller diameter cuff. For example, the cuff 601 may include electrode contacts 402 disposed on only one side (for example, either side) of the flexion zone 408 and the split 410. For example, the cuff 600 may be an example of the three-electrode-contact cuff 598.

[0227] In various examples, the tapered end 697 of the cuff 601 may end at one or more of the locations identified above with respect to the tapered end 697 of the cuff 600, provided that the tapered end 697 of the cuff 601 does not end at or after the beginning of the flap 404 (that is, provided that the sum of the range of degrees 693 and the second range of degrees 695 is not 360 degrees or more). In some examples, the conductor-access section 609 may occupy the entirety of the third range of degrees 696 (that is, the conductor-access section 609 may be contiguous with the non-tapered beginning of the flap 404 and the tapered end 697 of the flap 404), or may occupy only a portion of the third range of degrees (for example, the conductor- access section 609 may not be contiguous with either or both of the non-tapered beginning of the flap 404 and the tapered end 697 of the flap 404).

[0228] FIGS. 7A-7I illustrate various different implementations of the nerve cuff 400. FIGS. 7A- 71 illustrate examples of the nerve cuff 400 for purposes of explanation. Other implementations of the nerve cuff 400 are within the scope of the disclosure. For example, while certain example arrangements and numbers of the electrode contacts 402 are provided in FIGS. 7A-7I for purposes of example, the disclosure (including, for example, the number and arrangement of the electrode contacts 402) is not limited to the examples illustrated in FIGS. 7A-7I. Similarly, while example sizes, positions, and / or shapes of the closure flap 404, the flexion zone 408, and the split 410 are provided in FIGS. 7A-7I for purposes of example, the disclosure (including, for example, the length of the closure flap 404) is not limited to the examples illustrated in FIGS. 7A-7I.

[0229] FIG. 7A illustrates a cross-section view of a nerve cuff 700 according to another example. The nerve cuff 700 may be an example of the nerve cuff 400. The nerve cuff 700 includes several features that differ from those of the nerve cuff 500. For example, the nerve cuff 700 includes at least three modifications to the non-limiting example of the nerve cuff 500, including at least a split 702, a solid section 708, and the variable placement of the electrodes 402 as indicated by a trace 710. As discussed below, these differing features are all described with respect to FIG. 7A for ease of explanation and do not need to be implemented together. For example, the nerve cuff 500 may be modified to include a split similar to the split 702, but may not include the solid section 708. Accordingly, it is to be appreciated that any features of the nerve cuff 700 may be implemented together or separately.

[0230] The nerve cuff 700 may omit certain features for clarity of explanation. For example, the nerve cuff 700 may not explicitly illustrate conductor-access sections or channels for ease of explanation, but it is appreciated that the nerve cuff 700 may include conductor-access sections or channels in various implementations.

[0231] The nerve cuff 700 includes a split 702. The split 702 may be a different implementation of the split 410 as compared to the split of FIGS. 6A-6G. In FIGS. 6A-6G, the split is shown for example as a “V”- or keystone-shaped opening characterized by the wider width 646 and the narrower width 648 when the nerve cuff 500 is in a normal, equilibrium position, such that the two sections 604, 606 of the cuff body 406 do not physically contact one another around the split. Conversely, in the example of the nerve cuff 700, the split 702 may not include any substantial opening in a normal, equilibrium position of the nerve cuff 700. The nerve cuff 700 includes a first section 704 and a second section 706 separated by the split 702, similar to the first section 606 and the second section 606, respectively. In the normal, equilibrium position of the nerve cuff 700, the two sections 704, 706 of the cuff body 406 may physically contact or approximately physically contact one another at the split 702, whereas a gap exists between the sections 606, 608. In an implementation, the two section 704, 706 of the cuff body may approximately physically contact one another by being in close proximity to one another in the normal, equilibrium configuration. The nerve cuff 700 may be capable of being rotated out or flexed in a clamshell-like design to open the split 702 during insertion and / or removal of a nerve. Once the nerve cuff 700 is restored to its normal, equilibrium position, the split 702 may revert to being in a substantially closed position such that the two sections 704, 706 again contact one another or are within close proximity to one another.

[0232] As discussed above, the flexion zone 408 is an optional feature. The nerve cuff 700 may not include a flexion zone. Rather, the nerve cuff 700 may include a solid section 708 of substantially uniform thickness with the remainder of the cuff body 406 where the nerve cuff 500 might otherwise include the flexion zone 408.

[0233] As discussed above and in greater detail below, the nerve cuff 400 includes the electrodes 402. FIGS. 6A-6G illustrate the electrodes 402 being positioned at example locations along the inner surface 614 of the cuff body 406. In other examples, the electrodes 402 may be positioned at different locations along an inner surface of the cuff body 406. FIG. 7A illustrates a trace 710 indicating that the electrodes 402 may be positioned at any position and / or orientation around a circumference of an inner surface 712 of the cuff body 406. Furthermore, the electrodes 402 may be positioned at any position and / or orientation along a longitudinal axis of the nerve cuff 700.

[0234] Accordingly, the nerve cuff 500 illustrates one example of the nerve cuff 400. One or more features of the nerve cuff 400 may be omitted or modified, such as in the example of the nerve cuff 700. The nerve cuff 700 includes several modifications relative to the nerve cuff 500, and one or more of these modifications may be implemented together or separately. For instance, in a first example, an implementation of the nerve cuff 400 may be similar to the nerve cuff 500, except that the electrodes 402 arc shifted circumferentially around an inner surface of the nerve cuff 400 as indicated by the trace 710. In a second example, an implementation of the nerve cuff 400 may be similar to the nerve cuff 500, except that the implementation of the split 410 may be similar to the split 702. In a third example, an implementation of the nerve cuff 400 may be similar to the nerve cuff 500, except that the optional flexion zone 408 may be omitted and the nerve cuff 400 may instead include a solid section similar to the solid section 708.

[0235] FIGS. 7B-1 and 7B-2 illustrate additional examples of the split 410 according to respective examples. As discussed above with respect to the nerve cuff 500, the split 410 may be “V”- or keystone-shaped in some examples, with the wider width 646 at the top, or outer surface, of the cuff body 406, and the narrower width 648 at the bottom, or inner surface, of the cuff body 406. In other examples, the split 410 may have a size and / or shape different than the example of the nerve cuff 500.

[0236] FIG. 7B-1 illustrates a cross-section view of an example of a nerve cuff 712 having a rectangle-shaped split 714 according to an example. The split 714 may be an example of the split 410. The split 714 includes a top width 716 and a bottom width 718. The top width 716 may be approximately equal to the bottom width 718, that is, the split 714 may have a constant width.

[0237] FIG. 7B-2 illustrates a cross-section view of an example of a nerve cuff 720 having an inverted-“V”- or -key stone- shaped split 722 according to an example. The split 722 may be an example of the split 410. The split 722 includes a top width 724 and a bottom width 726. The top width 724 may be narrower than the bottom width 726. The split 722 is thus similar to the split 410 of the nerve cuff 500, except that in the case of the split 722, the wider opening of the split 722 is at the bottom width 726 and opens into the inside of the nerve cuff 720.

[0238] In various implementations of the nerve cuff 400, the split 410 may thus have any of several sizes and / or shapes, including those illustrated in the examples of FIGS. 5, 7A, 7B-1, and 7B-2. In other examples, other configurations of the split 410 may be implemented, including irregular and / or curved walls. Furthermore, while the sides of the split 410 may be symmetrical in some examples, in other examples the sides of the split 410 may not be symmetrical.

[0239] As discussed above, the cuff body 406 may include an optional flexion zone 408. FIG. 7C illustrates a cross-section of an example of a nerve cuff 725 having a flexion zone 739 with a gradual gradation in wall thickness for the cuff 729. The flexion zone 739 may cover a range 726 of degrees and may have a wall thickness that gradually varies across the range 726 from a thickness 727 characterizing the nerve cuff outside of the flexion zone 739 to a thickness 728 characterizing the thinnest portion of the flexion zone 739. As discussed above, the optional flexion zone 408 may include a groove having a “V” shape in some examples. In other examples, the flexion zone 408 may include a groove having a shape other than a “V” shape. For example, FIGS. 7D and 7E illustrate different examples of the flexion zone 408 with different groove shapes.

[0240] FIG. 7D illustrates a cross-section view of an example of a nerve cuff 728 having a rectangle-shaped groove 730 in a cuff body 732 of the nerve cuff 728 according to an example. The groove 730 extends partially into the cuff body 732 from an inner surface 734 of the cuff body 732 towards an outer surface 736 of the cuff body 732, defining a flexion zone wall 738 between the groove 730 and the outer surface 736. The flexion zone wall 738 has a wall thickness 740. In various examples, the size of the wall thickness 740 may vary to define a deeper or shallower groove. Similarly, a groove width 742 of the groove 730 may vary to define a narrower or wider groove.

[0241] FIG. 7E illustrates a cross-section view of an example of a nerve cuff 744 having a keystone-shaped groove 746 in a cuff body 748 of the nerve cuff 744 according to an example. The groove 746 extends partially into the cuff body 748 from an inner surface 750 of the cuff body 748 towards an outer surface 752 of the cuff body 748, defining a flexion zone wall 754 between the groove 746 and the outer surface 752. The flexion zone wall 754 has a wall thickness 756. In various examples, the size of the wall thickness 756 may vary to define a deeper or shallower groove.

[0242] The groove 746 is defined by a top width 758 which defines an opening into the inner surface 750 of the cuff body 748. The groove 746 narrows towards a bottom width 760 at the flexion zone wall 754. The bottom width 760 may be narrow such that the groove 746 forms a “V” shape with a vertex at the flexion zone wall 640 (e.g., as shown for example in FIGS. 6A and 6B). Alternatively, the groove 746 has a keystone shape with a flat section at the bottom width 760. Dimensions of the wall thickness 756, the top width 758, and the bottom width 760 may be varied to define a desired size and / or shape of the groove 746 in various examples.

[0243] As discussed above, the examples of FIGS. 7A-7E may be simplified at least inasmuch as the illustrated nerve cuffs do not explicitly illustrate conductor-access pathways. In various examples, the nerve cuffs of FIGS. 7A-7E may implement conductor-access pathways which are not explicitly illustrated for illustrative clarity. In some examples, a nerve cuff may include conductor- access pathways in any of several configurations. For example, as discussed above, the cuff body 406 includes a plurality of conductor access pathways, or channels, 610. The number of channels may depend on the number of electrodes in the nerve cuff and / or the number of electrical contacts needed for the IPG 12 to control the electrodes. In some examples, the channels 610 may include three channels in the first section 604 of the cuff body 406, and three channels in the second section 606 of the cuff body 406. Each of the sections 604, 606 may include a number and arrangement of conductoraccess channels in mirror-symmetry about the imaginary line 602 in some examples. As discussed in greater detail below, in other examples the channels 610 may include a different number and / or arrangement of conductor-access channels.

[0244] Each of the channels 610 may lead to a respective electrode contact of the electrode contacts 402. In examples in which the electrode contacts 402 include six electrode contacts, the channels 610 may include six channels. In other examples in which the electrode contacts 402 include a different number of electrode contacts, the channels 610 may include a different, corresponding number of channels. In an example, each conductor (for example, each of the conductors 412) may travel through a respective channel to a corresponding electrode. In this manner, a stimulation signal may be provided through a conductor to a corresponding electrode by traveling through the cuff body 406 via a respective channel.

[0245] For example, FIG. 7F illustrates a cross-section view of a nerve cuff 762 according to an example. The nerve cuff 762 may be substantially similar to the nerve cuff 700 of FIG. 7A, but explicitly illustrates an example of a conductor-access section 764 having a plurality of conductor- access channels 765. Accordingly, although the nerve cuff 762 may not include a flexion zone (and instead includes a solid section, as discussed above with respect to the solid section 708), the nerve cuff 762 may still include a conductor-access section 764.

[0246] The channels 765 define respective openings to receive respective conductors. In the illustrated example, the conductor-access section 764 includes six channels 765 for purposes of example. In other examples, a different number of channels may be implemented. The channels 765 of the conductor- access section 764 may be arranged in mirror- symmetry with each other about an imaginary line 766 bisecting the nerve cuff 762. In other examples, the channels 765 of the conductor-access section 764 may not be arranged in mirror-symmetry with each other.

[0247] FIG. 7G illustrates a cross-section view of a nerve cuff 768 according to another example. The nerve cuff 768 may be substantially similar to the nerve cuff 728 of FIG. 7D, but explicitly illustrates an example of a first conductor-access section 770 and a second conductoraccess section 772 each having a plurality of conductor-access channels. For example, the first conductor- access section 770 includes a first group of channels 771, and the second conductoraccess section 772 includes a second group of channels 773. Accordingly, although the nerve cuff 768 includes a flexion zone (as discussed above with respect to FIG. 7D), the nerve cuff 768 may still include conductor-access sections 770, 772.

[0248] Each of the groups of channels 771, 773 includes several channels defining respective openings to receive respective conductors. In the illustrated example, each of the groups of channels 771, 773 includes three channels for purposes of example. In other examples, a different number of channels may be implemented. The channels 771, 773 may be arranged in mirror- symmetry with each other about an imaginary line 774 bisecting the nerve cuff 768.

[0249] In other examples, the channels 771, 773 may not be arranged in mirror- symmetry with each other. In some examples, the channels 771, 773 may not include the same number of conductor- access channels.

[0250] For example, FIG. 7H illustrates a cross-section view of a nerve cuff 776 according to another example. The nerve cuff 776 is similar to the nerve cuff 768 of FIG. 7G, but includes a conductor- access section 778 on only one side of an imaginary line 780 bisecting the nerve cuff 776. The conductor- access section 778 includes a plurality of channels 779. Whereas the nerve cuff 768 includes two conductor-access sections 770, 772 arranged in mirror- symmetry about the imaginary line 774, the channels 779 in the nerve cuff 776 are not arranged in mirror-symmetry. Accordingly, in some examples, conductor-access channels may not be arranged in mirrorsymmetry.

[0251] FIG. 71 illustrates a cross-section view of a nerve cuff 782 according to another example. The nerve cuff 782 is similar to the nerve cuff 768 of FIG. 7G, but includes a first conductoraccess section 784 which is asymmetrical with a second conductor-access section 786 about an imaginary line 788. As illustrated in FIG. 71, the first conductor- access section 784 includes two conductor- access channels 785 and the second conductor-access section 786 includes four conductor-access channels 787. Accordingly, in some examples, conductor-access sections on either side of the imaginary line 788 may include different numbers of conductor- access channels. In light of FIGS. 7A-7I, various different implementations of the nerve cuff 400 are within the scope of the disclosure. For case of explanation, additional examples discussed below with respect to FIGS. 8A-8B are provided with respect to the example of the nerve cuff 500. However, the principles discussed below may be applicable to different implementations of the nerve cuff 400, including one or more of the examples of FIGS. 7A-7I.

[0252] FIG. 8A illustrates a top view of a cuff body 900 in an unrolled position according to an example. The cuff body 900 of FIG. 8 A may illustrate an example of the cuff body 406 pursuant to the example of the nerve cuff 500. As discussed above, the cuff body 406 may be a tubular cuff body with a cylindrical shape. FIG. 8 A illustrates the tubular cuff body 406 if the cuff body 406 were “unrolled” from the tubular, cylindrical shape into a flat, planar shape, which is not necessarily illustrated to scale. In various examples, the cuff body 406 may be constituted by a less flexible material and may not actually be capable of feasibly being unrolled into a flat planar shape. Accordingly, FIG. 8A may illustrate a hypothetical view of the unrolled cuff body 406 for purposes of example rather than an actual state of the cuff body 406.

[0253] As illustrated in FIG. 8A, the electrode contacts 402 include a first proximal electrode contact 800a, a first middle electrode contact 802a, and a first distal electrode contact 804a. As illustrated in FIG. 8A, the electrode contacts 402 further include a second proximal electrode contact 800b, a second middle electrode contact 802b, and a second distal electrode contact 804b. In various examples, the first electrode contacts 800a-804a are in mirror-symmetry about the longitudinal axis 508 with the second electrode contacts 800b-804b, respectively.

[0254] The electrode contacts 800a-804a, 800b-804b are distributed along the longitudinal axis 508, as shown in FIG. 5, and face inwards towards the center of the cuff. Accordingly, the electrode contacts 800a-804a, 800b-804b may face towards (and may be in physical contact with) a nerve encircled by the cuff body 406 and lying along the longitudinal axis 508. Applying an electric potential to one or more of the contacts 800a-804a, 800b-804b may cause one or more of the electrode contacts 800a-804a, 800b-804b to act as a cathodic contact, and at least one other as an anodic contact, such that an electrical stimulation current travels between the cathodic contact(s) and the anodic contact(s) through the nerve, thereby stimulating the nerve.

[0255] In various examples discussed below, current steering may be implemented to steer the electrical stimulation towards efferent nerve fibers (that is, motor nerve fibers) and away from afferent nerve fibers (that is, sensory nerve fibers). In some examples, each of the electrode contacts 800a-804a, 800b-804b may be capable of acting as a cathodic contact, and each of the electrode contacts 800a-804a, 800b-804b may be capable of acting as an anodic contact. Furthermore, each of the electrode contacts 800a-804a, 800b-804b may act as an anodic contact at one point in time, but may act as a cathodic contact at another point in time. As discussed below, the IPG 12 may select a desired anode-cathode pair to steer a stimulation current in a desired path (for example, towards efferent nerve fibers and away from afferent nerve fibers).

[0256] Each of the electrode contacts 800a-804a, 800b-804b is shown, for example, as implemented with a rounded-rectangle shape. However, in other examples, one or more of the electrode contacts 800a-804a may be implemented, for example, as a circle, an oval, a triangle, a square, a rectangle, or some other quadrilateral or parallelogram. Comers on shapes such as a triangle, square, rectangle, or some other quadrilateral or parallelogram may be rounded in some examples. The electrode contacts 800a-804a, 800b-804b may all have a same shape as shown herein by example, or may differ in shape in other examples.

[0257] The first proximal electrode contact 800a is characterized by a first proximal length 806. The first middle electrode contact 802a is characterized by a first middle length 808. The first distal electrode contact 804a is characterized by a first distal length 810. A total length of the cuff 500, from the proximal end 504 to the distal end 506, may be characterized by a total cuff length 812. The second proximal electrode contact 800b is characterized by a second proximal length 814. The second middle electrode contact 802b is characterized by a second middle length 816. The second distal electrode contact 804b is characterized by a second distal length 818.

[0258] The first proximal electrode contact 800a is spaced apart from the first middle electrode contact 802a by a first spacing 820. The first middle electrode contact 802a is spaced apart from the first distal electrode contact 804a by a second spacing 822. The second proximal electrode contact 800b is spaced apart from the second middle electrode contact 802b by a third spacing 824. The second middle electrode contact 802b is spaced apart from the second distal electrode contact 804b by a fourth spacing 826.

[0259] As discussed above, in various examples the first electrode contacts 800a-804a (which may be referred to as a first arrangement of electrode contacts on the inner surface 614) may be in mirror-symmetry with the second electrode contacts 800b-804b (which may be referred to as a second arrangement of electrode contacts on the inner surface 614) about the longitudinal axis 508. Accordingly, the first proximal electrode contact 800a may have the same size and shape as the second proximal electrode contact 800b, and may be located at a mirror-symmetrical position on the inner surface 614 of the first section 604 as the second proximal electrode contact 800b on the inner surface 614 of the second section 606. Accordingly, the first proximal electrode contact 800a and the second proximal electrode contact 800b may be located equidistant from, and on opposite sides of, the split 410. Similar principles may apply to the other electrode contacts 802a, 802b, 804a, 804b. The mirror-symmetry arrangement of the electrode contacts provides the advantage of enabling the implanter to adjust the position of the nerve cuff circumferentially around the nerve (that is, to rotate the cuff around the enclosed nerve). In contrast, asymmetric electrode contact positions may require a particular circumferential positioning.

[0260] Accordingly, in various examples, the first proximal length 806 may be approximately equal to the second proximal length 814; the first middle length 808 may be approximately equal to the second middle length 816; the first distal length 810 may be equal to the second distal length 818; the first spacing 820 may be equal to the third spacing 824; and the second spacing 822 may be equal to the fourth spacing 826. Furthermore, in some examples, all of the spacings 820-826 may be approximately equal to one another such that both the first arrangement of electrode contacts 800a-804a and the second arrangement of electrode contacts 800b-804b are evenly spaced along the longitudinal axis 508.

[0261] FIG. 8A illustrates the electrode contacts 800a-804a, 800b-804b with corresponding lengths 806-810, 814-818, respectively. Each of the electrode contacts 800a-804a, 800b-804b also has a corresponding width. In an actual implementation, the electrode contacts 800a-804a, 800b-804b may be curved into arcs along the inner surface 614 because the cuff body 406 may be a tubular cuff body 406. The width of each of the electrode contacts 800a-804a, 800b-804b may therefore be expressed as an arc length, which is equal to the inner radius 624 multiplied by a range of degrees (expressed in radians) that the respective contact spans along the inner surface 614 of the tubular cuff body 406. In view of this relationship, a width of each of the electrode contacts 800a-804a, 800b-804b may be referred to with reference to a range of degrees that the contact spans within the cuff body 406.

[0262] For example, the first proximal electrode contact 800a spans a first range of degrees 902 along the circumference of the inner surface 614 of the tubular cuff body 406. The first distal electrode contact 804a spans a second range of degrees 904 along the circumference of the inner surface 614 of the tubular cuff body 406. The second proximal electrode contact 800b spans a third range of degrees 906 along the circumference of the inner surface 614 of the tubular cuff body 406. The second distal electrode contact 804b spans a fourth range of degrees 908 along the circumference of the inner surface 614 of the tubular cuff body 406. The first middle electrode contact 802a spans a fifth range of degrees 910 along the circumference of the inner surface 614 of the tubular cuff body 406. The second middle electrode contact 802b spans a sixth range of degrees 912 along the circumference of the inner surface 614 of the tubular cuff body 406.

[0263] In various examples, the first range of degrees 902 and the second range of degrees 904 each overlap the fifth range of degrees 910. For example, the first range of degrees 902 and the second range of degrees 904 may be contiguous with one another, but may not overlap each other; that is, the first range of degrees 902 may end just as the second range of degrees 904 begins. In other examples, the ranges of degrees 902, 904 may at least partially overlap one another, and may each fall entirely within the fifth range of degrees 910.

[0264] Similarly, the third range of degrees 906 and the fourth range of degrees 908 may each overlap the sixth range of degrees 912. For example, the third range of degrees 906 and the fourth range of degrees 908 may be contiguous with one another, but may not overlap each other. In other examples, the ranges of degrees 906, 908 may at least partially overlap one another, and may each fall entirely within the sixth range of degrees 912.

[0265] In at least one example, the ranges of degrees 902, 904 partially overlap one another, and may each fall entirely within the fifth range of degrees 910. For example, from the perspective of FIG. 8A, the right-hand edge of the first proximal electrode contact 800a may be aligned longitudinally with the right-hand edge of the first middle electrode contact 802a, and the lefthand edge of the first distal electrode contact 804a may be aligned longitudinally with the lefthand edge of the first middle electrode contact 802a.

[0266] In an example in which the first proximal electrode contact 800a and the first distal electrode contact 804a each have a width of 1 mm, and the middle electrode contact 802a has a width of 1.75 mm, the widths of the electrode contacts 800a, 804a may “overlap” longitudinally for a shared width of approximately 0.25 mm, which corresponds to a common range of degrees that depends on the length of the inner radius 624.

[0267] Accordingly, in various examples the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be the same size as one another. Similarly, the middle electrode contacts 802a, 802b may each have the same size as one another. In various examples, a length-to-width aspect ratio of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be approximately 3:1, and a length-to- width aspect ratio of each of the middle electrode contacts 802a, 802b may be approximately 2:1.

[0268] In various examples, a length of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be between approximately 2 - 3 mm. In various examples, a width of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be approximately 1 mm.

[0269] In various examples, a length and / or width of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be another value. In some examples, a length and / or width of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be another value, provided that the length-to-width aspect ratio is approximately a certain ratio, such as approximately 2:1, 3:1, 4:1 or other ratio that enables a maximum surface area within the available space of the cuff.

[0270] In at least one example, a respective length of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be less than a respective length of each of the middle electrode contacts 802a, 802b. For example, a respective length of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be approximately 10 - 20% less than a respective length of each of the middle electrode contacts 802a, 802b.

[0271] In other examples, a respective length of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be greater than a respective length of each of the middle electrode contacts 802a, 802b. In other examples, a respective length of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be approximately equal to a respective length of each of the middle electrode contacts 802a, 802b.

[0272] In some examples, a respective length of one or more of the proximal electrode contacts 800a, 800b may be greater than or less than a respective length of one or more of the distal electrode contacts 804a, 804b. In various examples, each of the electrode contacts 800a-804a, 800b-804b may have different lengths.

[0273] In some examples, a length and / or width of each of the proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be another value, provided that a surface area of each of the electrode contacts 800a, 800b, 804a, 804b is at least a threshold value (and in some examples, provided that the length-to-width aspect ratio is approximately a certain ratio). For example, the threshold surface area may be a minimum surface area for an electrode contact to not dissolve, such as due to ionic transfer during stimulation.

[0274] In various examples, a length of each of the middle electrode contacts 802a, 802b may be between approximately 2 - 4 mm. In various examples, a width of each of the middle electrode contacts 802a, 802b may be approximately 1.5-2 mm.

[0275] In various examples, a length and / or width of each of the middle electrode contacts 802a, 802b may be another value. In some examples, a length and / or width of each of the middle electrode contacts 802a, 802b may be another value, provided that the length-to-width aspect ratio is approximately a certain ratio, such as approximately 2:1, 3:1, 4:1 or other ratio that enables a maximum surface area within the available space of the cuff.

[0276] In some examples, a length and / or width of each of the middle electrode contacts 802a, 802b may have various values, provided that a surface area of each of the middle electrode contacts 802a, 802b is at least a threshold value (and in some examples, provided that the length- to-width aspect ratio is approximately a certain ratio). For example, the threshold surface area may be a minimum surface area for an electrode contact to not dissolve, such as due to ionic transfer during stimulation.

[0277] In some examples, the total cuff length 812 may be approximately 11 - 14 mm, 10-14 mm, 12-13 mm, or, in some examples, approximately 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, approximately 12.5 mm, or approximately 12.4 mm.

[0278] In some examples, the flexion zone wall 640 includes perforations 914 (three of which are labeled with a reference number, and the remainder of which are unlabeled for illustrative clarity) through the cuff body 406. Each of the perforations 914 may include a respective opening through the flexion zone wall 640. As discussed above, the flexion zone 408 may enable the cuff body 406 to be opened in a clamshell-like configuration in response to an external force, such as an implanter prying the cuff body 406 open to rotate about the flexion zone wall 640. The flexion zone 408 may act as a torque hinge and may not rotate about the flexion zone wall 640 absent an external force. The perforations 914 may weaken the torque force of the flexion zone 408 such that the cuff body 406 is easier to rotate about the flexion zone wall 640. Accordingly, the perforations 914 may be used to facilitate the task of opening the cuff body 406 during implantation. As discussed below, the perforations 914 may also be designed to yield a desired response to nerve inflammation (for example, to yield a desired maximum pressure).

[0279] Various different sizes, shapes, and numbers of perforations 914 may be implemented. In some examples, the perforations 914 extend longitudinally down the entire length of the flexion zone wall 640. The perforations 914 may be positioned at regular intervals along the flexion zone wall 640. In other examples, the perforations 914 may be positioned at irregular intervals and / or may be isolated to a specific section of the flexion zone wall 640.

[0280] Furthermore, in some examples, the perforations 914 may be omitted entirely. For example, FIG. 8B illustrates a top view of a cuff body 950 in an unrolled position according to another example. Although the example in FIG. 8A includes six electrodes and the example in FIG. 8B includes three electrodes, examples of the cuff body 406 for either one of the six electrode or three electrode cuffs may or may not include perforations in various examples.

[0281] In an implementation, a nerve cuff may have fewer electrode contacts than the examples shown above. For example as shown in FIG. 8B, a nerve cuff may have three electrodes and lack a symmetrical arrangement of electrodes on either side of the longitudinal axis 508. For example, a nerve cuff with smaller dimensions, for example targeting an ansa cervicalis implementation as opposed to a phrenic nerve implementation may only accommodate three electrodes. Additionally, a nerve cuff for use on the ansa cervicalis may provide selective stimulation (e.g., steering stimulation current) or non-selective stimulation (e.g., no steering of stimulation current). For example, the ansa cervicalis may have little to no afferent fibers, thus there may not be a need to steer current on the ansa cervicalis to avoid afferent fiber stimulation.

[0282] The cuff of FIG. 8B includes a proximal electrode contact 990, a middle electrode contact 992, and a distal electrode contact 994. The distal electrode contact 994 is defined by a distal width 954 and a distal length 972. The middle electrode contact 992 is defined by a middle width 956 and a middle length 974. The proximal electrode contact 990 is defined by a proximal width 958 and a proximal length 976. The electrode contacts 990, 992, 994 may be substantially similar to the electrode contacts 800a, 802a, 804a, and a complete description thereof is not repeated for brevity.

[0283] In some examples, however, the dimensions of the electrode contacts 990-994 may differ from the electrode contacts 800a-804a. For example, the lengths 976, 972 of each of the proximal and distal electrode contacts 990, 994 in various examples may be approximately 1.25 - 2.25 mm or approximately 1 .5 - 2.5 mm or approximately 1 .5-2.0 mm. In some examples, the middle length 974 of the middle electrode contact 992 may be approximately 2.5-3.5 mm or 2.5

[0284] - 3 mm, or approximately 2.5 - 3.25 mm. In some examples, a length-to-width ratio of each of the electrode contacts 990, 992, 994 may be approximately 2:1 or 3:1.

[0285] The distal electrode contact 994 is separated from the middle electrode contact 992 by a first spacing 982, similar to the second spacing 822. The proximal electrode contact 990 is separated from the middle electrode contact 992 by a second spacing 984, similar to the first spacing 820. In various examples, the spacings 820-826, 982, and / or 984 may each be approximately 0.5 - 2 mm, or approximately 1 mm, or another value. In at least one example, the cuff body 950 is characterized by a cuff length 962. In some examples, the cuff length 962 may be in a range of 5-15 mm. In at least one example, the cuff length 962 may be approximately 10 mm.

[0286] FIG 9 illustrates a top view of a cuff body 901 in an unrolled position with surgical sutures according to an example. The cuff body 901 is an example of a six-electrode-contact cuff, and includes a first proximal electrode contact 946a, a second proximal electrode contact 946b, a first middle electrode contact 946c, a second middle electrode contact 946d, a first distal electrode contact 946e, and a second distal electrode contact 946f. However, the principles discussed in connection with the cuff body 901, including the implementation of surgical sutures, may also be applicable to three-electrode-contact cuffs, such as the cuff body 950 of FIG. 8B. No limitation is implied by the illustration of a six-electrode-contact example.

[0287] The cuff body 901 includes a grab area 940. The grab area 940 is a section of the cuff body 901 that a surgeon may grab during an implantation procedure. For example, the surgeon may grab the grab area 940 (for example, using a surgical instrument) to pull the cuff body 901 open (for example, by pulling a flap open), to manipulate the cuff for positioning around the target nerve, etc. FIGS. 13 and 14 describe the implantation procedure in greater detail.

[0288] The cuff body 901 may further optionally include, or may optionally be coupled to, a first optional suture or ligature 942a, a second optional suture or ligature 942b, and / or a third optional suture or ligature 942c. The optional sutures 942a, 942b may be coupled to the grab area 940 of the cuff body 901. The third optional suture 942c may be coupled to an opposite side of the cuff body 901. Each of the optional sutures 942a- 942c provides a structure for a surgeon to grab (for example, with a surgical instrument) and pull during implantation to open the cuff body 901. FIGS. 13 and 14 describe the implantation procedure in greater detail. The number of sutures and the presence of sutures on both sides of the cuff as shown in FIG. 9 arc examples only and not limiting of the disclosure. In various examples, the cuffs described herein may have no sutures or one or more sutures on one or both sides of the cuff.

[0289] The cuff body 901 may include, or be configured to be coupled to, one or more leads 944 (for example, one of the leads 300, 1200). The leads 944 may be coupled to the cuff body 901 before, during, or after implantation, as discussed in greater detail below with respect to FIGS. 13 and 14.

[0290] In various examples, the corners of the cuff body 901, including the corners of the closure flap of the cuff body 901, may have various shapes and / or profiles, such as by having square comers, rounded corners, or otherwise tapered corners.

[0291] As discussed above, the cuff body 406 may include the plurality of channels 610, each of which is configured to receive a corresponding one of the conductors 412. Examples of wiring configurations of the conductors 412 are discussed with respect to FIGS. 10A-10C.

[0292] FIG. 10A illustrates a top view of a cuff body 1000 in an unrolled position according to an example. The cuff body 1000 may illustrate another aspect of the nerve cuff 500 and includes examples of the conductors 412. The conductors 412 include a first conductor 1002a, a second conductor 1004a, a third conductor 1006a, a fourth conductor 1002b, a fifth conductor 1004b, and a sixth conductor 1006b. Each of the conductors 1002a- 1006b may be electrically coupled to a respective one of the electrode contacts 800a-804b. As discussed in detail below, in some examples, at least two of the conductors 1002a- 1006b may also be electrically coupled to one another.

[0293] For example, a first conductor 1002a may be electrically coupled to the first proximal electrode contact 800a. The first conductor 1002a may also extend to, and be electrically coupled to, the IPG 12 to deliver stimulation signals to the first proximal electrode contact 800a via the first conductor 1002a. In some examples, as discussed below, the first conductor 1002a may be directly electrically coupled to the fourth conductor 1002b. In some examples, the conductors 1002a, 1002b may be electrically coupled together at the distal bifurcation 306.

[0294] A second conductor 1004a may extend to the first middle electrode contact 802a. Accordingly, the second conductor 1004a may be electrically coupled to the first middle electrode contact 802a. The second conductor 1004a may also extend to, and be electrically coupled to, the IPG 12 to deliver stimulation signals to the first middle electrode contact 802a via the second conductor 1004a.

[0295] A third conductor 1006a may extend to the first distal electrode contact 804a. Accordingly, the third conductor 1006a may be electrically coupled to the first distal electrode contact 804a. The third conductor 1006a may also extend to, and be electrically coupled to, the IPG 12 to deliver stimulation signals to the first distal electrode contact 804a via the third conductor 1006a.

[0296] A fourth conductor 1002b may extend to the second proximal electrode contact 800b. Accordingly, the fourth conductor 1002b may be electrically coupled to the second proximal electrode contact 800b. The fourth conductor 1002b may also extend to, and be electrically coupled to, the IPG 12 to deliver stimulation signals to the second proximal electrode contact 800b via the fourth conductor 1002b. As discussed above, the fourth conductor 1002b may be electrically coupled to the first conductor 1002a such that the first proximal electrode contact 800a is electrically coupled to the second proximal electrode contact 800b.

[0297] A fifth conductor 1004b may extend to the second middle electrode contact 802b. Accordingly, the fifth conductor 1004b may be electrically coupled to the second middle electrode contact 802b. The fifth conductor 1004b may also extend to, and be electrically coupled to, the IPG 12 to deliver stimulation signals to the second middle electrode contact 802b via the fifth conductor 1004b.

[0298] A sixth conductor 1006b may extend to the second distal electrode contact 804b. Accordingly, the sixth conductor 1006b may be electrically coupled to the second distal electrode contact 804b. The sixth conductor 1006b may also extend to, and be electrically coupled to, the IPG 12 to deliver stimulation signals to the second distal electrode contact 804b via the sixth conductor 1006b.

[0299] As discussed above, in some examples, at least two of the conductors 1002a-1006b may be directly electrically coupled to each other such that the corresponding electrode contacts are electrically coupled to each other. These coupled conductors may be electrically coupled to one another upstream of the nerve cuff 500. For example, the coupled conductors may be electrically coupled to one another at the distal bifurcation 306. In such an example, a single conductor that enters the distal bifurcation 306 from the IPG 12 may split into two (or more) separate conductors. The junction of this single conductor in the distal bifurcation 306 may have a “Y” shape, in which the single conductor branches into two physically separate, but electrically coupled, conductors.

[0300] For example, a single conductor that enters the distal bifurcation 306 from the IPG 12 may split into the first conductor 1002a, which is coupled to the first proximal electrode contact 800a, and the fourth conductor 1002b, which is coupled to the second proximal electrode contact 800b. FIG. 10A illustrates this electrical coupling with a single conductor 1008 which is bifurcated into the first conductor 1002a and the fourth conductor 1002b. The single conductor 1008 may thus be referred to as the bifurcated single conductor 1008 in some examples. In this configuration, an electrical stimulation provided by the IPG 12 to the single conductor 1008 may be provided, via the bifurcation of the single conductor 1008, to both of the proximal electrode contacts 800a, 800b via the conductors 1002a, 1002b, respectively. Because the two proximal electrode contacts 800a, 800b are electrically coupled to one another in this example, the two proximal electrode contacts 800a, 800b may be considered to be electrically configured as a single proximal electrode.

[0301] Accordingly, in various examples, any one or more of the electrode contacts 800a-804b may be electrically coupled to any one or more of the other electrode contacts 800a-804b. Each set of two or more electrode contacts electrically coupled together in this manner may collectively be electrically configured as, and referred to as, an electrode. Furthermore, a single electrode contact which is not electrically coupled together in a short circuit configuration with any other electrode contact may also be considered to be electrically configured as, and referred to as, an electrode. Thus, an electrode may include one or more electrode contacts.

[0302] In some examples, two or more conductors may be hardwired together in a short-circuit configuration. In various examples, the conductors 1002a, 1002b may be hardwired together in the distal bifurcation 306 to electrically couple the proximal electrode contacts 800a, 800b to one another, forming a proximal electrode. In at least one example, the conductors 1006a, 1006b may also be hardwired together in the distal bifurcation 306 to electrically couple the distal electrode contacts 804a, 804b to one another, forming a distal electrode. In other examples, such as the example illustrated in FIG. 10A, the conductors 1006a, 1006b may not be hardwired together and thus the distal electrode contacts 804a, 804b may not be electrically coupled to one another.

[0303] Accordingly, in the example of FIG. 10A, at least the conductors 1002a, 1002b may be electrically coupled in a short-circuit configuration upstream of the electrode contacts 800a, 800b. In other examples, electrode contacts may be electrically coupled in a short-circuit configuration at a different location and / or through a different electrical-coupling structure.

[0304] For example, FIG. 10B illustrates a top view of a cuff body 1010 in an unrolled position according to an example. The cuff body 1010 is substantially similar to the cuff body 1000. However, whereas in the example of FIG. 10A the conductors 1002a, 1002b are electrically coupled to one another upstream of the cuff body 1000 at the bifurcated single conductor 1008, in FIG. 10B the conductors 1002a, 1002b are not electrically coupled to one another upstream of the cuff body 1010. Instead, the cuff body 1010 includes a conductor 1012 (e.g., a flexible ribbon or wire) within the cuff body 1010 and electrically coupling the first proximal electrode contact 800a to the second proximal electrode contact 800b. The proximal electrode contacts 800a, 800b may therefore be electrically coupled to one another within the cuff body 1010 and may be electrically configured as a single proximal electrode. In some examples, the conductor 1012 may sit within a channel in the cuff body 1010 and / or may be disposed along the inner surface of the cuff body to electrically couple the proximal electrode contacts 800a, 800b.

[0305] In some examples, ribbon conductors may be implemented in different configurations. For example, FIG. 10C illustrates a top view of a cuff body 1014 in an unrolled position according to an example. The cuff body 1014 is substantially similar to the cuff body 1010. However, whereas in the example of FIG. 10B the proximal electrode contacts 800a, 800b are electrically coupled together, in FIG. 10C the proximal electrode contacts 800a, 800b are not electrically coupled together.

[0306] Furthermore, the cuff body 1014 includes a ribbon conductor 1016 electrically coupled to the sixth conductor 1006b and the second distal electrode 804b. The cuff body 1014 may include a first section 1018 including the electrode contacts 800a- 804a, and a second section 1020 including the electrode contacts 800b-804b, where the longitudinal axis 508 bisects the cuff body 1014 into the two sections 1018, 1020. In various examples, the sixth conductor 1006b may enter the cuff body 1014 at the first section 1018, and the conductor 1016 (e.g., a flexible ribbon or wire) may extend from the sixth conductor 1006b in the first section 1018 to the second distal electrode contact 804b in the second section 1020. The conductor 1016 may sit within a channel in the cuff body 1014 or may be disposed along an inner surface of the cuff body.

[0307] In various examples, the lead 300 may include at least one switching device to dynamically switch which conductors, if any, are electrically coupled together. For example, the distal bifurcation 306 may house at least one switching device, such as a multiplexer, to dynamically switch connections between conductors (and thus electrode contacts). Accordingly, two of the electrode contacts 800a-804b may be electrically coupled together at one point in time, but may later be switched to be decoupled from one another at another point in time. In various examples, a controller such as the controller 16 may control the at least one switching device to switch to a desired switching state. The controller 16 may therefore control the at least one switching device to form any combination of electrodes from a set of electrode contacts.

[0308] As discussed above, in at least one example, the conductors 1002a, 1002b may be electrically coupled (for example, hardwired together) at the distal bifurcation 306 such that the proximal electrode contacts 800a, 800b are electrically coupled and are electrically configured as a proximal electrode. In some examples, the conductors 1006a, 1006b may also be electrically coupled (for example, hardwired together) at the distal bifurcation 306 such that the distal electrode contacts 804a, 804b are electrically coupled and are electrically configured as a distal electrode. The middle electrode contacts 802a, 802b may not be electrically coupled (that is, the conductors 1004a, 1004b may not be electrically coupled together, and the middle electrode contacts 802a, 802b are thus electrically isolated from one another), and thus the first middle electrode contact 802a may act as a first electrode, and the second middle electrode contact 802b may act as a second electrode.

[0309] In this example, therefore, there may be six total electrodes including a proximal electrode, a distal electrode, and two middle electrodes. In some examples, each of the six electrodes may act as an anode, a cathode, or both (that is, an anode at one point in time and a cathode at another point in time). These six anode-cathode pairs of electrodes may therefore include the proximal electrode 800a, 800b and the first middle electrode 802a; the proximal electrode 800a, 800b and the second middle electrode 802b; the distal electrode 804a, 804b and the first middle electrode 802a; the distal electrode 804a, 804b and the second middle electrode 802b; the proximal electrode 800a, 800b and the distal electrode 804a, 804b; and the first middle electrode 802a and the second middle electrode 802b. In these pairs, either electrode may act as an anode and either may act as an cathode.

[0310] Different anode-cathode pairs may be selected and stimulated to selectively steer the stimulation current. For example, the IPG 12 may control an anode-cathode -pair selection, that is, may control which electrode(s) acts as a cathode, and which electrode(s) acts as an anode. The IPG 12 may control which electrode(s) acts as a cathode by selectively providing a stimulation signal to the clcctrodc(s) to act as a cathodc(s). In some examples, the IPG 12 may control which electrode(s) acts as an anode by controlling at least one switching device to couple any desired anode(s) to the IPG 12, that is, to create a complete circuit between the stimulated cathode and a desired anode. In other examples, the IPG 12 may select which electrode(s) acts as an anode by simply not stimulating that electrode(s) while stimulating other electrodes to act as cathodes.

[0311] The IPG 12 may select different anode-cathode pairs to selectively steer the stimulation current to the nerve encircled by the cuff 400. Each anode-cathode pair may correspond to a different path for stimulation current. The path of the stimulation current between each anodecathode pair may be referred to as a current vector. The IPG 12 may select a desired current vector by providing electrical stimulation signals to a corresponding anode-cathode pair. In an example, the IPG 12 may deliver the electrical stimulation signal to the cathodic electrode of an anode-cathode pair where the anodic electrode provides the current return path. Alternatively, the IPG 12 may implement an anodal stimulation with delivery of the electrical stimulation signal to the anodic electrode of the anode-cathode pair where the cathodic electrode provides the current return path.

[0312] As discussed above, a cervical phrenic nerve may include bunches of motor nerve fibers (that is, efferent nerve fibers) and bunches of sensory nerve fibers (that is, afferent nerve fibers). It may be advantageous to steer the stimulation current to the motor nerve fibers while avoiding the sensory nerve fibers, for example, to select the current vector that predominantly stimulates (for example, passes through) motor nerve fibers. Accordingly, the IPG 12 may steer the stimulation current to the anode-cathode pair(s) that steer the stimulation current to the motor nerve fibers while avoiding the sensory nerve fibers.

[0313] An electrical stimulation applied by the IPG 12 across an anode-cathode pair depend on impedance and may be in the range of 0 - 16 V, with a current that may be in the range of 0 - 10 mA. A target may be approximately 3 V with a current of approximately 3 mA (assuming an impedance of approximately 1000 ohms).

[0314] In one example, after an implanter implants the cuff 400 over a nerve, medical personnel wait several weeks (for example, 4-6 weeks) for the patient to heal from the surgery. The cuff 400 may then be calibrated to deliver desired electrical stimulation. For example, medical personnel (including, for example, physicians, nurses, programmers of the IPG 12, a combination thereof, and so forth) may select parameters of the stimulation signal such as pulse rate, frequency, current, voltage, pulse width, and so forth. Medical personnel may also select a desired current vector.

[0315] As discussed above, each current vector may correspond to a respective anode-cathode pairing. Each anode-cathode pairing may yield a different current vector, and therefore a different response from the patient depending on the patient’s particular sensory and motor nerve fiber arrangement in the path of the current vector.

[0316] In an open-loop implementation of the IPG 12 and the nerve cuff, the current steering may be controlled via programmed instructions to the IPG 12. For example, during calibration, medical personnel may test one or more anode-cathode pairings and select a pairing based on the patient’s response. For example, the patient may give feedback as to whether and to what degree the stimulation elicits a sensory response (for example, pain or discomfort). A pairing that yields the lowest sensory response (for example, the least pain or discomfort) may be selected for the IPG 12 to deliver stimulation along the corresponding current vector.

[0317] For example, the external computing device 210 may provide a stimulation menu that may include icons or other controls that enable selection of stimulation parameters including electrode-selection parameters. Once a practitioner selects stimulation parameters from this menu, the stimulation parameters including the electrode selection parameters, the external computing device 210 communicates this selection back to the IPG 12 to effectively program the IPG 12 to implement the selected parameters via firmware and / or software downloaded to the IPG 12 before or after implantation. In an implementation, the external computing device 210 may automatically cycle through available parameters and based on feedback from a practitioner, patient, and / or a physiologic sensor, select a set of stimulation parameters including electrode selection parameters. In some instances, the external computing device 210 may provide a confirmation control and / or an editing control that allows a practitioner to confirm and / or edit automatically selected stimulation parameters.

[0318] In some examples, the patient may return for regular check-ins. At each of these checkins, a determination may be made as to whether to switch to a different anode-cathode pairing. For example, if a certain anode-cathode pairing previously produced no sensory response in the patient, but now produces a pain or discomfort response, a different anode-cathode pairing may be selected to minimize or eliminate the pain or discomfort response. In some examples, medical personnel may oversee the check-ins and decide which anode-cathode pairing to implement.

[0319] In a closed-loop implementation of the IPG 12 and the nerve cuff, the IPG 12 may automatically select and / or update the anode-cathode pairing without programmed instructions from the external computing device 210 based on input from a caregiver. For example, the IPG 12 may sense physiologic information indicative of whether and to what degree the stimulation current is eliciting a pain or discomfort response in the patient, and may automatically change the anode-cathode pairing responsive to determining the degree of pain or discomfort response. This physiologic information may include sensed information that correlates with pain or discomfort, such as heart rate, breathing rate, skin conductivity (for example, indicating sweating), and so forth. Additionally or alternatively, the IPG 12 may operate in a closed loop to select and / or adjust the anode-cathode pairing based on user feedback information indicative of the patient’s subjective perception of pain or discomfort in response to the stimulation current. Changes in one or more of the physiologic information or user feedback information in correlation with the applied stimulation current may cause the IPG 12 to update the anode-cathode pairing until the pain or discomfort response subsides.

[0320] In various examples, therefore, the electrode contacts 402 may include several electrode contacts, such as six electrode contacts, more than six electrode contacts, or fewer than six electrode contacts. An electrode may be formed from one or more electrode contacts. Thus, of the electrode contacts 402, several electrodes may be formed, including a number of electrodes that is equal to or less than the number of electrode contacts. The number and composition of electrodes may change over time if, for example, the electrode contacts arc switchably coupled and decoupled together (for example, via at least one switching device in the distal bifurcation 306 and / or the IPG 12) to be electrically configured and unconfigured as an electrode. Of each of these several electrodes, any may be controlled as an anode and any may be controlled as a cathode by the IPG 12 applying an appropriate stimulation current. Consequently, pairs of anodes and cathodes may be formed from any two electrodes. Coupling of electrodes may provide the advantages of increasing surface areas which in turn affects current densities and / or enabling a guarded cathode configuration and operation.

[0321] In some examples, each one of the six conductors 1002a, 1004a, 1006a, 1002b, 1004b, and 1006b may electrically be independent of each of the other six conductors 1002a, 1004a, 1006a, 1002b, 1004b, and 1006b. In this arrangement, each of the respective electrode contacts may be electrically independent from each of the other respective electrode contacts.

[0322] In the case of the three-electrode nerve cuff shown in FIG. 8B, the conductor arrangement may differ from that of the six-electrode nerve cuff shown, for example, in FIG. 8A. The electrode contacts in the three-electrode cuff may be electrically independent and / or the conductors may be electrically independent. In other examples, the electrode contacts and / or conductors in the three-electrode cuff may not be electrically independent.

[0323] For example, FIG. 10D illustrates the cuff body 950 including the electrode contacts 990- 994. In the illustrated example, the cuff body 950 includes a first conductor 1052 electrically coupled to the proximal electrode contact 990, a second conductor 1054 electrically coupled to the middle electrode contact 992, and a third conductor 1056 electrically coupled to the distal electrode contact 994. In some examples, the conductors 1052-1056 may be individually wired and electrically independent of one another to enable current steering. In other examples, one or more of the conductors 1052-1056 may be electrically wired together, for example, to support a non-selective, guarded-cathode arrangement.

[0324] For example, the conductors 1054, 1056 may be electrically wired together (or the electrode contacts 992, 994 may be directly electrically coupled), or the conductors 1052, 1056 may be electrically wired together (or the electrode contacts 990, 994 may be directly electrically coupled), or the conductors 1052, 1054 may be electrically wired together (or the electrode contacts 990, 992 may be directly electrically coupled). Accordingly, various examples are within the scope of the disclosure in which, for both three- and six-electrode-contact cuffs, contacts are wired independently or together. Contacts wired together may be electrically coupled together directly, and / or may be electrically coupled together via conductors which are electrically coupled together.

[0325] In some examples, the IPG 12 may be configured to generate approximately 0.3-1 mA of stimulation current with voltage across an anode-cathode pair adjusted according to impedance. In this example, there may be three total electrodes including a proximal electrode, a distal electrode, and a middle electrode. In some examples, each of the three electrodes may act as an anode, a cathode, or both (that is, an anode at one point in time and a cathode at another point in time). The selected anode-cathode pairs of electrodes may depend on whether the IPG provides stimulation current in a steering, or selective, configuration or in a non-steering, or non-selective, configuration.

[0326] In the selective configuration, the anode-cathode pairs may be the proximal electrode 990 and the distal electrode 994, the proximal electrode 990 and the middle electrode 992, or the middle electrode 992 and the distal electrode 994. In these pairs, either electrode may act as an anode and either may act as an cathode. In a non-selective configuration, also referred to as a guarded cathode configuration, the selected anode-cathode pairs may be the pair formed by a) the proximal electrode 990 and distal electrode 994 with b) the middle electrode 992, or the pair formed by a) the proximal electrode 990 and middle electrode 992 with b) the distal electrode 994, or the pair formed by a) the middle electrode 992 and distal electrode 994 with b) the proximal electrode 990. In these combinations, either of a pair of electrodes and the remaining single electrode, may act as an anode and either may act as an cathode.

[0327] The IPG 12 may control an anode-cathode-pair selection, that is, may control which electrode(s) acts as a cathode, and which electrode(s) acts as an anode. The IPG 12 may control which electrode(s) acts as a cathode by selectively providing a stimulation signal to the electrode(s) to act as a cathode(s). In some examples, the IPG 12 may control which electrode(s) acts as an anode by controlling at least one switching device to couple any desired anode(s) to the IPG 12, that is, to create a complete circuit between the stimulated cathode and a desired anode. In other examples, the IPG 12 may select which electrode(s) acts as an anode by simply not stimulating that electrode(s) while stimulating other electrodes to act as cathodes.

[0328] Various different arrangements of electrode contacts may be implemented. FIGS. 11A- 11H illustrate various configurations of electrode contacts. FIGS. 11A-11D illustrate various configurations of distal electrode contacts. FIGS. 11E-11H illustrate various configurations of proximal electrode contacts. Any of the examples of FIGS. 11A-11D may be combined with any of the examples of FIGS. I IE-11H. Although FIGS. 11 A-l 1H show examples for six-electrode- contact cuffs, the variations of sizes and arrangements may apply to the three-electrode-contact cuff shown in FIG. 8B.

[0329] FIG. 11 A illustrates a truncated top portion of a cuff body 1100 according to a first example. The cuff body 1100 includes a first section 1102 and a second section 1104 bisected by the longitudinal axis 508. The first section 1102 includes the first distal electrode contact 804a and the first middle electrode contact 802a. The second section 1104 includes the second distal electrode contact 804b and the second middle electrode contact 802b. In the example of FIG. 11 A, both of the distal electrode contacts 804a, 804b may be positioned on a left-hand side of the sections 1102, 1104, respectively.

[0330] FIG. 1 IB illustrates a truncated top portion of a cuff body 1106 according to a second example. The cuff body 1106 includes a first section 1108 and a second section 1110 bisected by the longitudinal axis 508. The first section 1108 includes the first distal electrode contact 804a and the first middle electrode contact 802a. The second section 1110 includes the second distal electrode contact 804b and the second middle electrode contact 802b. In the example of FIG. 1 IB, the first distal electrode contact 804a may be positioned on a left-hand side of the first section 1108, and the second distal electrode contact 804b may be positioned on a right-hand side of the second section 1110.

[0331] FIG. 11C illustrates a truncated top portion of a cuff body 1112 according to a third example. The cuff body 1112 includes a first section 1114 and a second section 1116 bisected by the longitudinal axis 508. The first section 1114 includes the first distal electrode contact 804a and the first middle electrode contact 802a. The second section 1116 includes the second distal electrode contact 804b and the second middle electrode contact 802b. In the example of FIG. 11C, both of the distal electrode contacts 804a, 804b may be positioned on a right-hand side of the sections 1114, 1116, respectively.

[0332] FIG. 1 ID illustrates a truncated top portion of a cuff body 1118 according to a fourth example. The cuff body 1118 includes a first section 1120 and a second section 1122 bisected by the longitudinal axis 508. The first section 1120 includes the first distal electrode contact 804a and the first middle electrode contact 802a. The second section 1122 includes the second distal electrode contact 804b and the second middle electrode contact 802b. In the example of FIG. 1 ID, the first distal electrode contact 804a may be positioned on a right-hand side of the first section 1120, and the second distal electrode contact 804b may be positioned on a left-hand side of the second section 1122. FIG. 1 IE illustrates a truncated bottom portion of a cuff body 1124 according to a fifth example. The cuff body 1124 includes a first section 1126 and a second section 1128 bisected by the longitudinal axis 508. The first section 1126 includes the first proximal electrode contact 800a and the first middle electrode contact 802a. The second section 1128 includes the second proximal electrode contact 800b and the second middle electrode contact 802b. In the example of FIG. 1 IE, the first proximal electrode contact 800a may be positioned on a right-hand side of the first section 1126, and the second proximal electrode contact 800b may be positioned on a left-hand side of the second section 1128.

[0333] FIG. 1 IF illustrates a truncated bottom portion of a cuff body 1130 according to a sixth example. The cuff body 1130 includes a first section 1132 and a second section 1134 bisected by the longitudinal axis 508. The first section 1132 includes the first proximal electrode contact 800a and the first middle electrode contact 802a. The second section 1134 includes the second proximal electrode contact 800b and the second middle electrode contact 802b. In the example of FIG. 1 IF, both of the proximal electrode contacts 800a, 800b may be positioned on a left-hand side of the sections 1132, 1134, respectively.

[0334] FIG. 11G illustrates a truncated bottom portion of a cuff body 1136 according to a seventh example. The cuff body 1136 includes a first section 1138 and a second section 1140 bisected by the longitudinal axis 508. The first section 1138 includes the first proximal electrode contact 800a and the first middle electrode contact 802a. The second section 1140 includes the second proximal electrode contact 800b and the second middle electrode contact 802b. In the example of FIG. 11G, the first proximal electrode contact 800a may be positioned on a left-hand side of the first section 1138, and the second proximal electrode contact 800b may be positioned on a right-hand side of the second section 1140.

[0335] FIG. 11H illustrates a truncated bottom portion of a cuff body 1142 according to an eighth example. The cuff body 1142 includes a first section 1144 and a second section 1146 bisected by the longitudinal axis 508. The first section 1144 includes the first proximal electrode contact 800a and the first middle electrode contact 802a. The second section 1146 includes the second proximal electrode contact 800b and the second middle electrode contact 802b. In the example of FIG. 11H, both of the proximal electrode contacts 800a, 800b may be positioned on a right-hand side of the sections 1144, 1146, respectively.

[0336] Some examples of the electrode contacts 402 discussed above may be considered to be implemented in a bipolar stimulation configuration. In a bipolar stimulation configuration, at least two electrode contacts in the nerve cuff may be implemented to act as an anode and a cathode. A stimulation current passes between the anodic and cathodic contacts of the nerve cuff. In contrast, in a unipolar stimulation configuration, current steering is achieved via a first electrode, that provides the cathodic contact and another structure, such as the housing of the IPG 12, that provides the anodic contact for current return. In this configuration, stimulation current passes from the single electrode contact to the other structure. However, in a unipolar arrangement, the current steering is less precise than current steering achieved by a bipolar nerve cuff.

[0337] In some examples, the cuff 500 may implement a guarded-cathode configuration. A guarded-cathode configuration may include a configuration in which a cathode is flanked on opposite sides by respective anodes. When a stimulation current travels between the cathode and the anodes, the stimulation current may be approximately evenly distributed between the flanking anodes. Because the anodes are positioned on opposite sides of the cathode, the stimulation current is largely captured by the anodes. In an arrangement in which a cathode and anode are implemented side-by-side, some stray current from the cathode may be lost from the cathode on the side of the cathode opposite the anode. Thus, guarded cathodes may be more energy-efficient than configurations without guarded cathodes.

[0338] The implementation of the guarded-cathode configuration may require physical changes to the wiring of the lead 300 that connects the IPG 12 to the nerve cuff 302 and the wiring connections to the nerve cuff 302. In an implementation, the guarded-cathode configuration may be a dynamically available configuration based on re-programming of the IPG 12. As an example, in order to implement a guarded-cathode configuration in the nerve cuff 500, the middle electrode contacts 802a, 802b may be electrically configured as individual electrodes and may be operated by the IPG 12 to act as cathodes. The proximal electrode contacts 800a, 800b and the distal electrode contacts 804a, 804b may be wired together to be electrically configured as an anode. Accordingly, the middle electrode contacts 802a, 802b are flanked on either side (along the longitudinal axis 508) by anodes and are therefore implemented in a guarded-cathode configuration. However, an implementation of the nerve cuff 500 as described herein as a guarded cathode would not allow current steering because all of the electrodes are utilized to achieve the guarded-cathode effect. The guarded-cathode arrangement enables focusing of current and minimization of leakage but does not allow the current steering achieved by selection of various electrode pairs.

[0339] As discussed above, the cuff body 406 opens at about the split 410. during implantation to implant the cuff body 406 around the target nerve. In some examples, the cuff body 406 may also open at the split 410 subsequent to the implant procedure responsive to nerve inflammation. Because the cuff body 406 encircles the nerve, if the diameter of the nerve expands (for example, due to inflammation), the nerve may apply a force on the inner surface 614 of the cuff body 406. This force may cause the cuff body 406 to open at the split 410. For example, the inner radial distance 624 may increase by up to 25-60% in some examples. The split 410 enables the nerve cuff 500 to accommodate changes in nerve diameter during ordinary use in electrical stimulation therapy and thus enhances the efficacy of the nerve cuff 500 in providing this therapy by helping to avoid or reduce trauma due to over-compression. For example, nerve swelling may occur and increase a nerve diameter. The flexion zone 408 may further improve the flexibility of the nerve cuff 500 and the ability of the nerve cuff 500 to respond to changes in nerve diameter.

[0340] Because the cuff body 406 expands with the nerve, an amount of pressure applied to the nerve may be less than if the cuff body 406 did not expand. The cuff body 406 may be configured to limit an amount of pressure on the nerve to below a threshold pressure. The threshold pressure may correspond to an amount of pressure that might damage a nerve. For example, the threshold pressure may be approximately 20 mmHg for a cervical phrenic nerve.

[0341] In various examples, parameters of the split 410, the flexion zone 408, and / or the perforations 914 (such as the size, shape, number, and position) may be selected to control an amount of pressure applied to the nerve. As discussed above, the perforations 914 may decrease the restoring force applied by the cuff body 406 to the nerve, and thus may decrease the pressure applied to the nerve. Accordingly, properties of the perforations 914 may be selected to maintain the pressure below the threshold pressure.

[0342] In some examples, parameters of the flexion zone 408 may also be selected to control the amount of pressure applied to the nerve. For example, in the example of a “V”-shaped groove with an opening on the inner surface 614 of the cuff body 406, an angle or other dimension of the groove opening may be selected to control the amount of pressure applied to the nerve. For example, a wider angle may reduce the restoring force applied by the cuff body 406. A narrower angle may increase the restoring force applied by the cuff body 406. The thickness of material in the flexion zone 408 may also affect restoring force. In some examples, the angle may be selected to be between approximately 40-50° or between approximately 46-48” or between approximately 15-25° or between 25-45° or between 15-20° or between 33-38° to achieve a desired pressure below a threshold pressure. The optimum angle may depend on the diameter of the cuff. In other examples, other parameters of the cuff body 406 may be selected to achieve a desired maximum pressure applied to the nerve, such as the material of the cuff body 406, the values of the radial distances 624-628, and so forth.

[0343] As discussed above, in some examples the IPG 12 may couple to the leads 14 via a pair of contact pins, such as the proximal bifurcated conductors 312 as shown in FIG. 3. In other examples, the IPG 12 may couple to embodiments of the leads 14 via a single contact pin. For example, FIG. 12 illustrates a single-contact-pin lead 1200. The single-contact-pin lead 1200 includes a single terminal pin 1202, which includes a plurality of ring contacts 1204. Three of the contacts 1204 are labeled in FIG. 12 for illustrative clarity, but the contacts 1204 may include additional contacts (for example, six contacts) each capable of conducting a respective stimulation current.

[0344] FIGS. 13 and 14 illustrate a method of implant for a nerve cuff according to an example. FIG. 13 illustrates a process 1300 of implanting a nerve cuff and an IPG according to an example. FIG. 14 illustrates a process 1400 of placing a nerve cuff around a target nerve, which may be a subprocess of the process 1300, according to an example.

[0345] At act 1310, a surgeon makes incisions in the patient’s body for implantation of the nerve cuff and of the IPG. For a patient under anesthesia, the surgeon, generally a neurophysiologist, may make incisions at sites near the nerve cuff implant location and the IPG implant location. Act 1310 may include making a first incision at a first implant location (for example, an implant location for the nerve cuff) and a second incision at a second implant location (for example, an implant location for the IPG). For example, the first incision for the nerve cuff may be in a cervical region of the patient’s body proximate to the phrenic nerve, the hypoglossal nerve, or the ansa cervicalis. The second incision for the IPG may be in the chest in an infraclavicular location.

[0346] At act 1320, the surgeon places and implant the nerve cuff around the target nerve. Upon exposure of the target nerve (e.g., phrenic nerve, hypoglossal nerve, or ansa cervicalis) via incisions in overlying tissues, the surgeon may place the nerve cuff around the target nerve at a desired location, for example, following the process discussed below with respect to FIG. 14.

[0347] At act 1330, the surgeon places and implants the IPG within a second implant location, such as a subcutaneous pocket formed via the incision. The surgeon may place the IPG in the pocket and then secures the IPG with suture anchors. At act 1340, the surgeon tunnels the lead from the nerve cuff to the IPG. The surgeon may create a subcutaneous tunnel from the nerve cuff incision area to the IPG incision location and draw the lead from the nerve cuff to the IPG.

[0348] At act 1350, the surgeon connects the lead to the IPG and conducts electrical testing. The surgeon may anchor the lead in the IPG pocket using sutures. Subsequently, the surgeon may perform electrical testing on the nerve cuff and lead using an external stimulation device and then connect the stimulation lead to the IPG upon successful completion of the electrical testing. For example, the external stimulation device may include an external pulse generator.

[0349] At act 1360, the surgeon closes the incisions to complete the implant procedure. For example, the surgeon may close the first and second incisions.

[0350] As discussed above, FIG. 14 illustrates a process 1400 of placing a nerve cuff around a target nerve. For example, the target nerve may be a phrenic nerve, a hypoglossal nerve, and / or the ansa cervicalis. The process 1400 may be an example of act 1320.

[0351] At act 1410, the surgeon may grasp one of a grab area of a cuff flap or a flap suture with a first surgical instrument. For example, the surgeon may grasp the grab area 940 or a similar grab area, and / or may grasp one or more of the optional sutures or ligatures 942a-942c or similar structures.

[0352] At act 1420, while grasping the cuff with the first surgical instrument as discussed in act 1410, the surgeon may position the cuff on the medial side of the nerve.

[0353] At act 1430, the surgeon may reach under the nerve from the lateral side of the nerve to the medial side of the nerve and may grab the other of the grab area of the cuff flap or the flap suture with a second instrument to open the cuff to accept the nerve. For example, if the surgeon grasped the third optional suture or ligature 942c with the first instrument, the surgeon may grasp the grab area 940 or one of the optional sutures or ligatures 942a, 942b with the second instrument. The surgeon may then pull the nerve cuff open using one or both instruments.

[0354] At act 1440, after opening the nerve cuff, the surgeon may draw the cuff under the nerve and position the flexion zone underneath the nerve.

[0355] At act 1450, the surgeon may stop holding the nerve cuff open by relaxing a hold on the grab area 940 and / or optional sutures or ligatures 942a-942c to encircle the nerve. Relaxing the hold on the cuff enables the cuff to restore its original shape (for example, a cylindrical shape) around the nerve. At act 1460, the surgeon tests the nerve activation and adjusts the cuff position if necessary. For example, the surgeon may perform electrical testing on the nerve cuff using an external stimulation device to determine whether the position of the nerve cuff is producing a desired nerve-activation response. The surgeon may adjust the position of the nerve cuff (for example, by rotating the nerve cuff radially around the nerve or moving the nerve cuff axially along the nerve) until the electrical testing yields the results desired by the surgeon.

[0356] At act 1470, the surgeon anchors the lead to the surrounding tissue. For example, because the electrical testing performed at act 1460 yielded a desired nerve-activation response, the surgeon may wish to anchor the lead at that location.

[0357] After act 1470, the process 1400 may end. Because the process 1400 may be an example of act 1320, act 1330 may follow act 1470. As discussed above, act 1330 may include tunneling the lead from the nerve cuff, which has been placed through execution of the process 1400, to the IPG, and so forth.

[0358] As discussed above, some electrode contacts of the electrode contacts 402 may be electrically configured as a single electrode. For example, a pair of electrode contacts may be considered to be electrically configured as a single electrode when the electrode contacts are electrically coupled together in a short circuit configuration by a conductor of the nerve cuff 500 (for example, by the conductors 412). The conductor may be bifurcated at the distal bifurcation 306, for example, from which two separate but conductively linked conductors connect to respective electrode contacts of the pair of electrode contacts. In various examples, therefore, a pair of electrode contacts may be considered electrically configured as a single electrode if the electrode contacts are coupled by a conductor of the nerve cuff 500 in a short circuit configuration.

[0359] FIG. 2 illustrates a block diagram of a medical device and computing device system 200. The system 200 includes the computing device 210 according to an example. While in some examples the computing device 210 is a tablet type of computer or a mobile phone such as a smartphone, the computing device 210 can include other types of computers and is therefore described in the context of a general computing device. In its most basic configuration, the computing device 210 includes at least a processing unit 102 and a memory 104. Depending on the exact configuration and type of computing device, the memory 104 may be volatile (such as RAM), non-volatile (such as ROM, flash memory, and so forth) or some combination of the two. This most basic configuration is illustrated in FIG. 2 within box 106.

[0360] Additionally, the computing device 210 may also have additional features and / or functionality. For example, the computing device 210 may also include additional storage (removable and / or non-removable) including, but not limited to, magnetic or optical disks or tapes, USB flash drives, memory cards, and so forth. Such additional storage is illustrated in FIG. 2 by a removable storage 108 and a non-removable storage 110. Computer- storage media may include volatile and / or nonvolatile media, removable and / or non-removable media, and so forth, implemented in any method or technology for storage of information such as computer- readable instructions, data structures, program modules or other data. The memory 104, the removable storage 108, and the non-removable storage 110 are all examples of computer-storage media, also referred to as non-transitory computer-readable media. Computer- storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CDROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and which can be accessed by the computing device 210. Any such computer- storage media may be part of computing device 210.

[0361] System memory 104 may include operating system 130, one or more programming modules or applications 132, and program data 134. Operating system 130, for example, may be suitable for controlling the operation of the computing device 210. As stated above, a number of programming modules or applications 132 and program data files 134 may be stored in system memory 104, including operating system 130. While executing on processing unit 102, programming modules or applications 132 may perform processes including, for example, one or more methods described herein, using one or more of the GUI screens or windows shown and described herein.

[0362] Program modules or applications may include routines, programs, components, data structures, and other types of structures that may perform particular tasks or that may implement particular abstract data types. Moreover, disclosed examples may be practiced with other computer- system configurations, including multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. Disclosed examples may also be practiced in distributed computing environments where tasks are performed by remote processing devices linked through a communications network. Tn a distributed computing environment, program modules may be located in both local and remote memory storage devices.

[0363] Furthermore, some disclosed examples may be practiced in an electrical circuit including discrete electronic elements, packaged or integrated electronic chips containing logic gates, a circuit utilizing a microprocessor, or on a single chip containing electronic elements or microprocessors. Some disclosed examples may also be practiced using other technologies capable of performing logical operations such as, for example, AND, OR, and NOT, including but not limited to mechanical, optical, fluidic, and quantum technologies.

[0364] The computing device 210 may also contain at least one communications interface 112 that allow the device to communicate with other devices. The at least one communications interface 112 can include, for example, wired media connections such as a wired network or direct- wired connection, and wireless media connections such as acoustic, RF, infrared, and other wireless media connections. In some examples, the at least one communications interface 112 is configured to provide communication (for example, wireless communication) between the computing device 210 and the IPG 12 of treatment system 10. For example, such communications may include processor instructions provided by a programmer of the IPG 12 to select particular anode-cathode pairs corresponding to a desired current vector (that is, to implement current steering). Thus, in some examples, the at least one communications interface 112 includes circuitry configured to provide communication connection as a wireless communication connection as described above.

[0365] In still other examples, such as in which the computing device 210 is coupled with or replaced by remote or cloud-based computing device(s) 38 for some or all of the processing functions described herein, the at least one communications interface 112 can communicate through an internet connection or other network 34, to the computing device(s) 38. In still other examples, the processing functions described herein are performed without the use of an external computing device 210, and are instead incorporated into the treatment system 10 and / or the computing device(s) 38. In some examples, the treatment system 10 performs at least a portion of the processing functions described herein, and a remaining portion, if any, of the processing functions may be performed by the computing device 210 and / or one or more alternative or additional computing devices, such as the remote or cloud-based computing devices 38. The description herein is provided in the context of processing functions being provided at least partially by computing device 210, but those of skill in the art will understand that such functions can be implemented outside of computing device 210.

[0366] In some examples the computing device 210 has, or can be coupled to, a touch screen display device 116 which provides a touch-based GUI. The computing device 210 may also have, or be coupled to, one or more input devices 114, such as a keyboard, mouse, pen, voice input device, and so forth, for providing other input (for example, user feedback) to the computing device 210. The computing device 210 may be coupled to one or more other output devices 118 such as speakers, a printer, a vibration generator, and so forth. Further, display device 116, input devices 114 and output devices 118 can all be considered to be separate from, or alternatively part of, the computing device 210. The computing device 210 can be provided with a portable or non-portable power source 120, such as a battery pack, a transformer, a power supply, or the like. The power source 120 provides power for computations, communications and so forth by the computing device 210.

[0367] Having thus described several aspects of at least one embodiment, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of, and within the spirit and scope of, this disclosure. Accordingly, the foregoing description and drawings are by way of example only.

[0368] What is claimed is:

Claims

CLAIMS1. A nerve cuff for treating disordered breathing in a patient, the nerve cuff comprising: a tubular cuff body configured to encircle a phrenic nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the phrenic nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the phrenic nerve and away from sensory fibers of the phrenic nerve; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

2. The nerve cuff of claim 1, wherein the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pairs of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

3. The nerve cuff of claim 2, wherein the pair of proximal electrode contacts comprises a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts comprises a first distal electrode contact and a second distal electrode contact,wherein the pair of middle electrode contacts comprises a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

4. The nerve cuff of claim 3, wherein the first arrangement of electrode contacts is arranged in mirror-symmetry with the second arrangement of electrode contacts across the longitudinal axis.

5. The nerve cuff of claim 2, wherein a length of each electrode contact of the pairs of proximal and distal electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the pairs of proximal and distal electrode contacts is between approximately 2 - 3 mm, wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm, and wherein a length to width ratio of each electrode contact of the pairs of proximal, middle, and distal electrodes is approximately 2:1, 3:1, or 4:1.

6. The nerve cuff of claim 2, wherein the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein: a) the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, b) the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and c) the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode.

7. The nerve cuff of claim 6,wherein the tubular cuff body comprises a plurality of conductor-access pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductoraccess pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor- access pathways and electrically coupled a respective electrode of the plurality of electrodes.

8. The nerve cuff of claim 7, wherein the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and wherein the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another via a second pair of conductors of the plurality of conductors.

9. The nerve cuff of claim 7, wherein the plurality of conductors is configured to create six selectable anode-cathode pairs of electrodes to selectively steer the stimulation current.

10. The nerve cuff of claim 9, wherein the IPG is configured to control an anode-cathode pair selection from the plurality of electrodes to selectively steer the stimulation current towards the motor fibers of the phrenic nerve and away from the sensory fibers of the phrenic nerve.

11. The nerve cuff of claim 9, wherein the IPG is configured to control the anode-cathode pair selection via the plurality of conductors.

12. The nerve cuff of claim 9, wherein the IPG is configured to apply approximately 3 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate approximately 3 mA of current.

13. The nerve cuff of claim 9, wherein the IPG is configured to apply a range of 0-16 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate a range of 0-10 mA of current.

14. The nerve cuff of claim 7, wherein each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof.

15. The nerve cuff of claim 7, wherein the inner surface is at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the phrenic nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body further comprising: a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the phrenic nerve and characterized by a first arc length that is less than a circumference of the tubular cuff body, and a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the phrenic nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and wherein an arc length of the conductor-access section along the second outer surface is equal to the second arc length.

16. The nerve cuff of claim 15, wherein the inner radial distance is approximately 1 mm and wherein the second outer radial distance is approximately 2 mm.

17. The nerve cuff of claim 15, wherein the inner radial distance is in a range of 0.5- 1.5 mm.

18. The nerve cuff of claim 17, wherein the second outer radial distance is in a range of 1.5 - 2.5 mm.

19. The nerve cuff of claim 1, wherein a length of the tubular cuff body is in a range of 5-15 mm.

20. The nerve cuff of claim 19, wherein the length of the tubular cuff body is approximately 12.4 mm.

21. The nerve cuff of claim 1, wherein the closure flap has an outer surface, and wherein the outer surface of the closure flap is free of any radial protrusions.

22. The nerve cuff of claim 1, wherein the closure flap extends along an entire length of the nerve cuff from a proximal end of the tubular cuff body to a distal end of the tubular cuff body.

23. The nerve cuff of claim 22, wherein the closure flap extends along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to a flexion zone.

24. The nerve cuff of claim 23, wherein the arc length corresponds to an angular range that terminates prior to a mid-line of the flexion zone.

25. The nerve cuff of claim 1, further comprising at least one flexion zone.

26. The nerve cuff of claim 25, wherein the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body.

27. The nerve cuff of claim 25, wherein the at least one flexion zone comprises a groove in a wall of the tubular cuff body.

28. The nerve cuff of claim 25, wherein the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards an outer surface of the tubular cuff body to form a flexion zone wall bounded by the outer surface.

29. The nerve cuff of claim 25, wherein the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body.

30. The nerve cuff of claim 25, wherein the at least one flexion zone is positioned radially opposite the split.

31. The nerve cuff of claim 25, wherein the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split.

32. The nerve cuff of claim 25, wherein the opening defined by the split in the tubular cuff body is characterized by a first width from an outer surface of the first section to an outer surface of the second section, and a second width from an inner surface of the first section to an inner surface of the second section, and wherein the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone.

33. The nerve cuff of claim 32, wherein the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width.

34. The nerve cuff of claim 1 , wherein the phrenic nerve comprises a cervical phrenic nerve.

35. A nerve cuff for treating disordered breathing in a patient, the nerve cuff comprising: a tubular cuff body configured to encircle an ansa cervicalis positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the ansa cervicalis into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

36. The nerve cuff of claim 35, wherein the plurality of electrodes is physically arranged as a proximal electrode contact, a middle electrode contact, and a distal electrode contact, wherein the proximal electrode contact is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the middle or distal electrode contact, wherein the distal electrode contact is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the proximal or middle electrode contacts, and wherein the middle electrode contact is located between the proximal electrode contact and the distal electrode contact relative to the longitudinal axis.

37. The nerve cuff of claim 36, wherein the proximal electrode contact, the middle electrode contact, and the distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body without any electrodes in the second section of the tubular cuff body.

38. The nerve cuff of claim 36, wherein a length of each electrode contact of the proximal and distal electrode contacts is less than a length of the middle electrode contact, wherein a length of each electrode contact of the proximal and distal electrode contacts is between approximately 1.5-2. O mm,wherein a length of the middle electrode contact is between approximately 2.5 - 3.0 mm, and wherein a length to width ratio of each electrode contact of the proximal, middle, and distal electrodes is approximately 2:1 or 3:1.

39. The nerve cuff of claim 36, wherein the nerve cuff is configured to provide non-selective stimulation without current steering.

40. The nerve cuff of claim 39, wherein two of the proximal, middle, and distal electrode contacts are electrically coupled and one of the proximal, middle, and distal electrode contacts is electrically isolated from the two electrically coupled electrode contacts.

41. The nerve cuff of claim 40, wherein a) the proximal electrode contact is electrically coupled to the distal electrode contact, and b) the middle electrode contact is electrically isolated from the proximal electrode contact and the distal electrode contact.

42. The nerve cuff of claim 40, wherein a) the middle electrode contact is electrically coupled to one of the distal electrode contact or the proximal electrode contact, and b) the other of the distal electrode contact or the proximal electrode contact is electrically isolated from the electrically coupled electrode contacts.

43. The nerve cuff of claim 36, wherein the nerve cuff is configured to provide selective stimulation through current steering.

44. The nerve cuff of claim 43, wherein each of the proximal, middle, and distal electrode contacts is electrically isolated from others of the proximal, middle, and distal electrode contacts.

45. The nerve cuff of claim 35, wherein the tubular cuff body comprises a plurality of conductor-access pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductoraccess pathways leading from a proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, andwherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor- access pathways and electrically coupled a respective electrode of the plurality of electrodes.

46. The nerve cuff of claim 45, wherein the conductor-access section protrudes from a surface of the tubular cuff body.

47. The nerve cuff of claim 46, wherein the protruding conductor-access section extends along the tubular cuff body parallel to the longitudinal axis.

48. The nerve cuff of claim 35, wherein the IPG is configured to generate approximately 0.3- 1 mA of stimulation current.

49. The nerve cuff of claim 35, wherein the IPG is configured to apply a range of 0-16 V across anode-cathode pairs and generate a range of 0-10 mA of current.

50. The nerve cuff of claim 35, wherein an inner radial distance is approximately 0.5 mm and a second outer radial distance is approximately 1.3 mm.

51. The nerve cuff of claim 35, wherein a length of the tubular cuff body is in a range of 5-15 mm.

52. The nerve cuff of claim 51, wherein the length of the tubular cuff body is approximately 10 mm.

53. The nerve cuff of claim 35, wherein an inner radial distance is in a range of 0.5-1.5 mm.

54. The nerve cuff of claim 53, wherein a second outer radial distance is in a range of 0.9- 1.7 mm.

55. The nerve cuff of claim 35, wherein the closure flap has an outer surface, and wherein the outer surface of the closure flap is free of any radial protrusions from an outer surface of the closure flap.

56. The nerve cuff of claim 35, wherein the closure flap extends along an entire length of the nerve cuff from a proximal end of the tubular cuff body to a distal end of the tubular cuff body.

57. The nerve cuff of claim 56, wherein the closure flap extends along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to a flexion zone.

58. The nerve cuff of claim 57, wherein the arc length corresponds to an angular range that terminates prior to a mid-line of the flexion zone.

59. The nerve cuff of claim 35, further comprising at least one flexion zone.

60. The nerve cuff of claim 59, wherein the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body.

61. The nerve cuff of claim 59, wherein the at least one flexion zone comprises a groove in a wall of the tubular cuff body.

62. The nerve cuff of claim 59, wherein the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards an outer surface of the tubular cuff body to form a flexion zone wall bounded by the outer surface.

63. The nerve cuff of claim 59, wherein the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body.

64. The nerve cuff of claim 59, wherein the at least one flexion zone is positioned radially opposite the split.

65. The nerve cuff of claim 59, wherein the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split.

66. The nerve cuff of claim 59, wherein the opening defined by the split in the tubular cuff body is characterized by a first width from an outer surface of the first section to an outer surface of the second section, and a second width from an inner surface of the first section to an inner surface of the second section, and wherein the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone.

67. The nerve cuff of claim 66, wherein the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width.

68. A treatment system for treating sleep disordered breathing in a patient, the system comprising: an implantable pulse generator (IPG); and a nerve cuff configured to electrically couple to the IPG, the nerve cuff comprising: a tubular cuff body configured to encircle a phrenic nerve positioned approximately along a longitudinal axis of the tubular cuff body,a split configured to enable insertion of the phrenic nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the phrenic nerve and away from sensory fibers of the phrenic nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

69. A treatment system for treating sleep disordered breathing in a patient, the system comprising: an implantable pulse generator (IPG); and a nerve cuff configured to electrically couple to the IPG, the nerve cuff comprising: a tubular cuff body configured to encircle an ansa cervicalis positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the ansa cervicalis into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

70. A method of implanting a nerve cuff for treating sleep disordered breathing in a patient, the method comprising: making a first incision at a first implant location on the patient; placing the nerve cuff around a target nerve in the first implant location, the nerve cuff comprising a plurality of electrodes; subcutaneously tunneling at least one electrical lead extending from the nerve cuff to a second implant location for an implantable pulse generator (IPG); and electrically testing the plurality of electrodes with an external pulse generator.

71. The method of claim 70, comprising:making a second incision at a second implant location on the patient; placing the IPG subcutaneously at the second implant location; and connecting the nerve cuff to the implantable pulse generator.

72. The method of claim 71, comprising closing the second incision.

73. The method of claim 70, comprising closing the first incision.

74. The method of claim 70, wherein placing the nerve cuff around the target nerve comprising placing the nerve cuff around a phrenic nerve.

75. The method of claim 74, wherein the phrenic nerve comprises a cervical phrenic nerve.

76. The method of claim 74, wherein the nerve cuff comprises: a tubular cuff body configured to encircle the phrenic nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body; a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the phrenic nerve and away from sensory fibers of the phrenic nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

77. The method of claim 70, wherein placing the nerve cuff around the target nerve comprising placing the nerve cuff around an ansa cervicalis.

78. The method of claim 77, wherein the nerve cuff comprises: a tubular cuff body configured to encircle the ansa cervicalis positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the ansa cervicalis into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body; a plurality of electrodes disposed on an inner surface of the tubular cuff body; anda plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

79. The method of claim 70, wherein placing the nerve cuff around the target nerve comprises: grasping the nerve cuff with a first surgical instrument; positioning the nerve cuff on a first side of the target nerve; reaching under the target nerve from a second side of the target nerve with a second surgical instrument to open the nerve cuff; drawing the nerve cuff under the target nerve; locating a flexion zone of the nerve cuff below the target nerve; and releasing the nerve cuff from the first and second surgical instruments to allow the nerve cuff to encircle the target nerve.

80. The method of claim 79, wherein the first side of the target nerve is a medial side and the second side is a lateral side, and comprising drawing the nerve cuff under the target nerve from the medial side to the lateral side.

81. The method of claim 79, wherein the first side of the target nerve is a lateral side and the second side is a medial side, and comprising drawing the nerve cuff under the target nerve from the lateral side to the medial side.

82. The method of claim 79, wherein grasping the nerve cuff with the first surgical instrument comprising grasping a nerve cuff closure flap or at least one nerve cuff suture.

83. The method of claim 79, wherein grasping the nerve cuff with the second surgical instrument comprising grasping a nerve cuff closure flap or at least one nerve cuff suture.

84. The method of claim 79, comprising testing nerve activation from the nerve cuff.

85. The method of claim 84, comprising adjusting a position of the nerve cuff along or around the target nerve based on the nerve activation testing.

86. The method of claim 79, comprising anchoring the at least one electrical lead to surrounding tissues.

87. A nerve cuff for treating disordered breathing in a patient, the nerve cuff comprising: a tubular cuff body configured to encircle a hypoglossal nerve positioned approximately along a longitudinal axis of the tubular cuff body,a split configured to enable insertion of the hypoglossal nerve into the tubular cuff body, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body; and a plurality of conductors configured to electrically couple an implantable pulse generator (IPG) to the plurality of electrodes.

88. The nerve cuff of claim 87, wherein the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pairs of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

89. The nerve cuff of claim 87, wherein the tubular cuff body comprises a plurality of conductor-access pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductoraccess pathways leading from a proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor- access pathways and electrically coupled a respective electrode of the plurality of electrodes.

90. The nerve cuff of claim 89, wherein each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof.

91. The nerve cuff of claim 89,wherein the inner surface is at an inner radial distance from the longitudinal axis and configured to face towards the hypoglossal nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body further comprising: a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the hypoglossal nerve and characterized by a first arc length that is less than a circumference of the tubular' cuff body, and a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the hypoglossal nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and wherein an arc length of the conductor-access section along the second outer surface is equal to the second arc length.

92. The nerve cuff of claim 91, wherein the inner radial distance is approximately 1.0 mm and wherein the second outer radial distance is approximately 2 mm.

93. The nerve cuff of claim 91, wherein the inner radial distance is in a range of 0.5-1.5 mm.

94. The nerve cuff of claim 93, wherein the second outer radial distance is in a range of 1-2.5 mm.

95. The nerve cuff of claim 87, wherein a length of the tubular cuff body is in a range of 5-15 mm.

96. The nerve cuff of claim 95, wherein a length of the tubular cuff body is approximately 12.4 mm.

97. The nerve cuff of claim 87, wherein the closure flap has an outer surface, and wherein the outer surface of the closure flap is free of any radial protrusions.

98. The nerve cuff of claim 87, wherein the closure flap extends along an entire length of the nerve cuff from a proximal end of the tubular cuff body to a distal end of the tubular cuff body.

99. The nerve cuff of claim 98, wherein the closure flap extends along an arc length corresponding to an angular range that is greater than 180 degrees and terminates proximate to a flexion zone.

100. The nerve cuff of claim 99, wherein the arc length corresponds to an angular range that terminates prior to a mid-line of the flexion zone.

101. The nerve cuff of claim 99, wherein the flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards an outer surface of the tubular cuff body to form a flexion zone wall bounded by the outer surface.

102. The nerve cuff of claim 99, wherein the flexion zone is positioned radially opposite the split.

103. The nerve cuff of claim 99, wherein the tubular cuff body is configured to rotate about the flexion zone to expand a width of the split.

104. The nerve cuff of claim 87, wherein the plurality of electrodes are configured to selectively steer stimulation of the hypoglossal nerve.

105. The nerve cuff of claim 87, wherein the plurality of electrodes are configured for non- selective stimulation of the hypoglossal nerve.

106. An implantable nerve cuff for electrically stimulating a nerve of a patient comprising: a tubular cuff body characterized by a longitudinal axis and having a proximal end at a first location along the longitudinal axis and a distal end at a second location along the longitudinal axis, the tubular cuff body configured to encircle a nerve approximately along the longitudinal axis of the tubular cuff body, the tubular cuff body comprising: an inner surface at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the nerve and the inner radial distance being approximately constant along the longitudinal axis, a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to face away from the nerve and characterized by a first arc length that is less than a circumference of the tubular cuff body,a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the first and second outer radial distances are approximately constant along the longitudinal axis, and a split extending from the inner surface to the first outer surface along the tubular' cuff body parallel to the longitudinal axis, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section; a closure flap configured to wrap around the first outer surface, wherein the closure flap. a) is configured to be fixedly coupled to the first section of the tubular cuff body and configured to be releasably coupled to the second section of the tubular cuff body in a closed flap position, b) has a flap thickness approximately equal to a difference between the first outer radial distance and the second outer radial distance such that the nerve cuff has an approximately constant cuff radius equal to the second outer radial distance with the closure flap in the closed flap position; and c) has an inner flap length greater than or approximately equal to the first arc length and less than the circumference of the tubular cuff body; and a plurality of electrodes disposed on the inner surface of the tubular cuff body and configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve.

107. The nerve cuff of claim 106, wherein the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to the proximal end relative to the longitudinal axis than the pairs of middle or distal electrode contacts, wherein the pair of distal electrode contacts is located closer to the distal end relative to the longitudinal axis than the pair of proximal or middle electrode contacts, andwherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

108. The nerve cuff of claim 107, wherein the pair of proximal electrode contacts comprises a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts comprises a first distal electrode contact and a second distal electrode contact, wherein the pair of middle electrode contacts comprises a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact arc arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

109. The nerve cuff of claim 108, wherein the first arrangement of electrode contacts is arranged in mirror-symmetry with the second arrangement of electrode contacts across the longitudinal axis.

110. The nerve cuff of claim 109, wherein the first proximal electrode contact and the second proximal electrode contact are arranged in mirror- symmetry across the longitudinal axis, wherein the first middle electrode contact and the second middle electrode contact are arranged in mirror-symmetry across the longitudinal axis, and wherein the first distal electrode contact and the second distal electrode contact are arranged in mirror symmetry across the longitudinal axis.

111. The nerve cuff of claim 109, wherein; the first proximal electrode contact spans a first range of degrees along a circumference of the inner surface of the tubular cuff body; the first distal electrode contact spans a second range of degrees along the circumference of the inner surface of the tubular cuff body;the second proximal electrode contact spans a third range of degrees along the circumference of the inner surface of the tubular cuff body; the second distal electrode contact spans a fourth range of degrees along the circumference of the inner surface of the tubular cuff body; the first middle electrode contact spans a fifth range of degrees along the circumference of the inner surface of the tubular cuff body; and the second middle electrode contact spans a sixth range of degrees along the circumference of the inner surface of the tubular cuff body, and wherein: the first range of degrees and the second range of degrees each overlap the fifth range of degrees and without overlapping each other, and the third range of degrees and the fourth range of degrees each overlap the sixth range of degrees and without overlapping each other.

112. The nerve cuff of claim 111, wherein the first range of degrees is contiguous with the second range of degrees, and the third range of degrees is contiguous with the fourth range of degrees.

113. The nerve cuff of claim 111, wherein: the first proximal electrode contact is longitudinally separated from the first middle electrode contact by a first spacing, the first distal electrode contact is longitudinally separated from the first middle electrode contact by a second spacing, the second proximal electrode contact is longitudinally separated from the second middle electrode contact by a third spacing, and the second distal electrode contact is longitudinally separated from the second middle electrode contact by a fourth spacing, and wherein the first spacing, the second spacing, the third spacing, and the fourth spacing are approximately equal to one another such that the first arrangement of electrode contacts is evenly spaced along the longitudinal axis and the second arrangement of electrode contacts is evenly spaced along the longitudinal axis.

114. The nerve cuff of claim 111,wherein the first proximal electrode contact and the second proximal electrode contact arc located equidistant from and on opposite sides of the split, wherein the first middle electrode contact and the second middle electrode contact are located equidistant from and on opposite sides of the split, and wherein the first distal electrode contact and the second distal electrode contact are located equidistant from and on opposite sides of the split.

115. The nerve cuff of claim 107, wherein a length-to-width aspect ratio of the proximal and distal pairs of electrode contacts is approximately 3:1, and wherein a length-to-width aspect ratio of the pair of middle electrode contacts is approximately 2:1.

116. The nerve cuff of claim 115, wherein each electrode contact of the pair of proximal electrode contacts, the pair of middle electrode contacts, and the pair of distal electrode contacts is shaped as quadrilateral comprising a rounded-corner rectangle.

117. The nerve cuff of claim 107, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is between approximately 2 - 3 mm, and wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm.

118. The nerve cuff of claim 107, wherein the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein: a) the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, b) the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and c) the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode.

119. The nerve cuff of claim 1 18, wherein the tubular cuff body comprises a plurality of conductor-access pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductoraccess pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein the nerve cuff further comprises a plurality of conductors each disposed at a respective pathway of the plurality of conductor- access pathways and electrically coupled a respective electrode of the plurality of electrodes.

120. The nerve cuff of claim 119, wherein the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and wherein the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another via a second pair of conductors of the plurality of conductors.

121. The nerve cuff of claim 119, wherein the plurality of conductors is configured to create six selectable anode-cathode pairs of electrodes to selectively steer the stimulation current.

122. The nerve cuff of claim 121, wherein the six selectable anode-cathode pairs of electrodes are a) the proximal electrode and the first middle electrode, b) the proximal electrode and the second middle electrode, c) the distal electrode and the first middle electrode, d) the distal electrode and the second middle electrode, e) the proximal electrode and the distal electrode, and f) the first middle electrode and the second middle electrode.

123. The nerve cuff of claim 119, wherein the plurality of conductors is configured to electrically couple to an implantable pulse generator (IPG) configured to control an anodecathode pair selection.

124. The nerve cuff of claim 119,wherein each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof.

125. The nerve cuff of claim 119, wherein the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and the second outer surface, and wherein an arc length of the conductor-access section along the second outer surface is equal to the second arc length.

126. The nerve cuff of claim 106, wherein a length of the tubular cuff body is in a range of 5- 15 mm.

127. The nerve cuff of claim 126, wherein a length of the tubular cuff body is approximately 12.4 mm.

128. The nerve cuff of claim 106, wherein the inner radial distance is approximately 1 mm and wherein the second outer radial distance is approximately 2 mm.

129. The nerve cuff of claim 106, wherein the inner radial distance is in a range of 0.5- 1.5 mm.

130. The nerve cuff of claim 106, wherein the second outer radial distance is in a range of 1.5- 2.5 mm.

131. The nerve cuff of claim 106, wherein the closure flap has an outer surface, and wherein the outer surface of the closure flap and the second outer surface of the tubular cuff body have an approximately constant radius relative to the longitudinal axis such that the nerve cuff is free of any radial protrusions from the outer surface of the closure flap and the second outer surface.

132. The nerve cuff of claim 131, wherein the outer surface of the closure flap has a third arc length and a circumference of the nerve cuff is approximately equal to a sum of the third arc length and the second arc length.

133. The nerve cuff of claim 106, wherein the closure flap extends along an entire length of the nerve cuff from the proximal end of the tubular cuff body to the distal end of the tubular cuff body.

134. The nerve cuff of claim 106, wherein at least one of the closure flap or the first outer surface of the first section of the tubular cuff body comprises or is coupled to a bonding materialsuch that the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

135. The nerve cuff of claim 134, wherein the closure flap is configured to be in physical contact with the first outer surface of the second section of the tubular cuff body when the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

136. The nerve cuff of claim 106, further comprising at least one flexion zone.

137. The nerve cuff of claim 136, wherein the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body.

138. The nerve cuff of claim 137, wherein the at least one flexion zone comprises a groove in a wall of the tubular cuff body.

139. The nerve cuff of claim 136, wherein the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward from the inner surface towards the second outer surface to form a flexion zone wall bounded by the second outer surface.

140. The nerve cuff of claim 136, wherein the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body.

141. The nerve cuff of claim 136, wherein the at least one flexion zone is positioned radially opposite the split.

142. The nerve cuff of claim 136, wherein the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split.

143. The nerve cuff of claim 136, wherein the opening defined by the split in the tubular cuff body is characterized by a first width from the first outer surface of the first section to the first outer surface of the second section, and a second width from the inner surface of the first section to the inner surface of the second section, and wherein the first width and the second width expand responsive to a rotation of the nerve cuff about the at least one flexion zone.

144. The nerve cuff of claim 143, wherein the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width.

145. The nerve cuff of claim 106, wherein the nerve comprises a cervical phrenic nerve.

146. The nerve cuff of claim 106, further comprising one or more sensor electrodes.

147. The nerve cuff of claim 146, wherein the one or more sensor electrodes comprise at least one of an electromyography sensor, an accelerometer, or an acoustic sensor.

148. A treatment system for treating disordered breathing in a patient, the system comprising: an implantable pulse generator (IPG); and a nerve cuff configured to electrically couple to the IPG, the nerve cuff comprising: a tubular cuff body configured to encircle a nerve positioned approximately along a longitudinal axis of the tubular cuff body, a split configured to enable insertion of the nerve into the tubular cuff body, a closure flap configured to wrap around the tubular cuff body, a plurality of electrodes disposed on an inner surface of the tubular cuff body configured to selectively steer stimulation current towards motor fibers of the nerve and away from sensory fibers of the nerve; and a plurality of conductors configured to electrically couple the IPG to the plurality of electrodes.

149. The treatment system of claim 148, wherein the tubular cuff body is characterized by the longitudinal axis and has a proximal end at a first location along the longitudinal axis and a distal end at a second location along the longitudinal axis, wherein the inner surface is at an inner radial distance from the longitudinal axis, the inner surface configured to face towards the nerve and the inner radial distance being approximately constant along the longitudinal axis, the tubular cuff body comprising: a first outer surface approximately concentric with the inner surface and at a first outer radial distance from the longitudinal axis, the first outer surface configured to faceaway from the nerve and characterized by a first arc length along a first range of degrees, the first arc length being less than a circumference of the tubular cuff body, a second outer surface approximately concentric with the inner surface and at a second outer radial distance from the longitudinal axis that is greater than the first outer radial distance, the second outer surface configured to face away from the nerve and characterized by a second arc length that is less than the first arc length and less than the circumference of the tubular cuff body, wherein the first and second outer radial distances are approximately constant along the longitudinal axis, and the split extending from the inner surface to the first outer surface along the tubular cuff body parallel to the longitudinal axis, the split defining an opening in the tubular cuff body that divides the tubular cuff body into a first section and a second section, and wherein the closure flap a) is configured to be fixedly coupled to the first section of the tubular cuff body and configured to be releasably coupled to the second section of the tubular cuff body in a closed flap position, b) has a flap thickness approximately equal to a difference between the first outer radial distance and the second outer radial distance such that the nerve cuff has an approximately constant cuff radius equal to the second outer radial distance with the closure flap in the closed flap position; c) has an inner flap length approximately equal to the first arc length; and d) is configured to wrap around the first outer surface.

150. The treatment system of claim 148, wherein the plurality of electrodes is physically arranged as a pair of proximal electrode contacts, a pair of middle electrode contacts, and a pair of distal electrode contacts, wherein the pair of proximal electrode contacts is located closer to a proximal end of the tubular cuff body relative to the longitudinal axis than the pairs of middle or distal electrode contacts,wherein the pair of distal electrode contacts is located closer to a distal end of the tubular cuff body relative to the longitudinal axis than the pair of proximal or middle electrode contacts, and wherein the pair of middle electrode contacts is located between the pair of proximal electrode contacts and the pair of distal electrode contacts relative to the longitudinal axis.

151. The treatment system of claim 150, wherein the plurality of electrodes is electrically configured as a proximal electrode, a first middle electrode, a second middle electrode, and a distal electrode, and wherein: a) the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another to provide the proximal electrode, b) the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to provide the distal electrode, and c) the middle electrode contacts of the pair of middle electrode contacts are electrically isolated from one another to provide the first middle electrode and the second middle electrode.

152. The treatment system of claim 151, wherein the tubular cuff body comprises a plurality of conductor-access pathways in a conductor-access section of the tubular cuff body, each pathway of the plurality of conductoraccess pathways leading from the proximal end of the tubular cuff body to a respective electrode of the plurality of electrodes, and wherein each conductor of the plurality of conductors is disposed at a respective pathway of the plurality of conductor-access pathways and electrically coupled a respective electrode of the plurality of electrodes.

153. The treatment system of claim 152, wherein the proximal electrode contacts of the pair of proximal electrode contacts are electrically coupled to one another via a first pair of conductors of the plurality of conductors, and wherein the distal electrode contacts of the pair of distal electrode contacts are electrically coupled to one another to via a second pair of conductors of the plurality of conductors.

154. The treatment system of claim 152,wherein the plurality of conductors is configured to create six selectable anode-cathode pairs of electrodes to selectively steer the stimulation current.

155. The treatment system of claim 154, wherein the six selectable anode-cathode pairs of electrodes are a) the proximal electrode and the first middle electrode, b) the proximal electrode and the second middle electrode, c) the distal electrode and the first middle electrode, d) the distal electrode and the second middle electrode, e) the proximal electrode and the distal electrode, f) the first middle electrode and the second middle electrode.

156. The treatment system of claim 154, wherein the IPG is configured to control an anodecathode pair selection.

157. The treatment system of claim 156, wherein the IPG is configured to control the anodecathode pair selection based on a user-selected anode-cathode pair selection.

158. The treatment system of claim 156, wherein the IPG is configured to control the anodecathode pair selection based on sensory feedback information indicative of a sensory response by the patient to the stimulation current.

159. The treatment system of claim 158, wherein the sensory feedback information includes one or more of heart-rate information, skin-conductivity information, breathing-rate information, user-feedback information.

160. The treatment system of claim 154, wherein the IPG is configured to apply approximately 3 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate approximately 3 mA of current.

161. The treatment system of claim 154, wherein the IPG is configured to apply a range of 0-16 V across an anode-cathode pair selected from the six selectable anode-cathode pairs and generate a range of 0-10 mA of current.

162. The treatment system of claim 150, wherein the pair of proximal electrode contacts comprises a first proximal electrode contact and a second proximal electrode contact, wherein the pair of distal electrode contacts comprises a first distal electrode contact and a second distal electrode contact,wherein the pair of middle electrode contacts comprises a first middle electrode contact and a second middle electrode contact, wherein the first proximal electrode contact, the first middle electrode contact, and the first distal electrode contact are arranged in a first arrangement of electrode contacts on the inner surface in the first section of the tubular cuff body, and wherein the second proximal electrode contact, the second middle electrode contact, and the second distal electrode contact are arranged in a second arrangement of electrode contacts on the inner surface in the second section of the tubular cuff body.

163. The treatment system of claim 162, wherein the first arrangement of electrode contacts is arranged in mirror-symmetry with the second arrangement of electrode contacts across the longitudinal axis.

164. The treatment system of claim 163, wherein the first proximal electrode contact and the second proximal electrode contact are arranged in mirror- symmetry across the longitudinal axis, wherein the first middle electrode contact and the second middle electrode contact are arranged in mirror-symmetry across the longitudinal axis, and wherein the first distal electrode contact and the second distal electrode contact are arranged in mirror symmetry across the longitudinal axis.

165. The treatment system of claim 164, wherein: the first proximal electrode contact spans a first range of degrees along a circumference of the inner surface of the tubular cuff body; the first distal electrode contact spans a second range of degrees along the circumference of the inner surface of the tubular cuff body; the second proximal electrode contact spans a third range of degrees along the circumference of the inner surface of the tubular cuff body; the second distal electrode contact spans a fourth range of degrees along the circumference of the inner surface of the tubular cuff body; the first middle electrode contact spans a fifth range of degrees along the circumference of the inner surface of the tubular cuff body; andthe second middle electrode contact spans a sixth range of degrees along the circumference of the inner surface of the tubular cuff body, and wherein: the first range of degrees and the second range of degrees each overlap the fifth range of degrees and without overlapping each other, and the third range of degrees and the fourth range of degrees each overlap the sixth range of degrees and without overlapping each other.

166. The treatment system of claim 165, wherein the first range of degrees is contiguous with the second range of degrees, and the third range of degrees is contiguous with the fourth range of degrees.

167. The treatment system of claim 165, wherein: the first proximal electrode contact is longitudinally separated from the first middle electrode contact by a first spacing, the first distal electrode contact is longitudinally separated from the first middle electrode contact by a second spacing, the second proximal electrode contact is longitudinally separated from the second middle electrode contact by a third spacing, and the second distal electrode contact is longitudinally separated from the second middle electrode contact by a fourth spacing, and wherein the first spacing, the second spacing, the third spacing, and the fourth spacing are approximately equal to one another such that the first arrangement of electrode contacts is evenly spaced along the longitudinal axis and the second arrangement of electrode contacts is evenly spaced along the longitudinal axis.

168. The treatment system of claim 165, wherein the first proximal electrode contact and the second proximal electrode contact are located equidistant from and on opposite sides of the split, wherein the first middle electrode contact and the second middle electrode contact are located equidistant from and on opposite sides of the split, and wherein the first distal electrode contact and the second distal electrode contact are located equidistant from and on opposite sides of the split.

169. The treatment system of claim 150, wherein a length-to-width aspect ratio of the proximal and distal pairs of electrode contacts is approximately 3:1, and wherein a length-to-width aspect ratio of the pair of middle electrode contacts is approximately 2:1.

170. The treatment system of claim 169, wherein each electrode contact of the pair of proximal electrode contacts, the pair of middle electrode contacts, and the pair of distal electrode contacts is shaped as quadrilateral comprising a rounded-corner rectangle.

171. The treatment system of claim 150, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is less than a length of each electrode contact of the pair of middle electrode contacts, wherein a length of each electrode contact of the proximal and distal pairs of electrode contacts is between approximately 2 - 3 mm, and wherein a length of each electrode contact of the pair of middle electrode contacts is between approximately 2.5 - 3.5 mm.

172. The treatment system of claim 152, wherein each pathway of the plurality of conductor-access pathways includes at least a first section that extends parallel to the longitudinal axis and is disposed within the tubular cuff body, along a surface of the tubular cuff body, or a combination thereof.

173. The treatment system of claim 172, wherein the conductor-access section occupies a sector of the tubular cuff body bound by the inner surface and an outer surface of the tubular cuff body, and wherein an arc length of the conductor-access section along the second outer surface is equal to an arc length of the outer surface.

174. The treatment system of claim 149, wherein the inner radial distance is approximately 0.5 mm and wherein the second outer radial distance is approximately 1 mm.

175. The treatment system of claim 149, wherein a length of the tubular’ cuff body is in a range of 5-15 mm.

176. The treatment system of claim 175, wherein a length of the tubular cuff body is approximately 14 mm.

177. The treatment system of claim 149, wherein the inner radial distance is in a range of 0.5- 1.5 mm.

178. The treatment system of claim 149, wherein the second outer radial distance is in a range of 1.5 - 2.5 mm.

179. The treatment system of claim 149, wherein the closure flap has an outer surface, and wherein the outer surface of the closure flap and the second outer surface of the tubular cuff body have an approximately constant radius relative to the longitudinal axis such that the nerve cuff is free of any radial protrusions from the outer surface of the closure flap and the second outer surface.

180. The treatment system of claim 179, wherein the outer surface of the closure flap has a third arc length and a circumference of the nerve cuff is approximately equal to a sum of the third arc length and the second arc length.

181. The treatment system of claim 149, wherein the closure flap extends along an entire length of the nerve cuff from the proximal end of the tubular cuff body to the distal end of the tubular cuff body.

182. The treatment system of claim 149, wherein at least one of the closure flap or the first outer surface of the first section of the tubular cuff body comprises or is coupled to a bonding material such that the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

183. The treatment system of claim 182, wherein the closure flap is configured to be in physical contact with the first outer surface of the second section of the tubular cuff body when the closure flap is fixedly coupled to the first outer surface of the first section by the bonding material.

184. The treatment system of claim 149, further comprising at least one flexion zone.

185. The treatment system of claim 184, wherein the at least one flexion zone comprises a thinner walled area of the tubular cuff body relative to a remainder of the tubular cuff body.

186. The treatment system of claim 185, wherein the at least one flexion zone comprises a groove in a wall of the tubular cuff body.

187. The treatment system of claim 184, wherein the at least one flexion zone extends longitudinally along an entire length of the tubular cuff body and extends radially outward fromthe inner surface towards the second outer surface to form a flexion zone wall bounded by the second outer surface.

188. The treatment system of claim 184, wherein the at least one flexion zone comprises a plurality of perforations, each perforation comprising a respective opening through the tubular cuff body.

189. The treatment system of claim 184, wherein the at least one flexion zone is positioned radially opposite the split.

190. The treatment system of claim 184, wherein the tubular cuff body is configured to rotate about the at least one flexion zone to expand a width of the split.

191. The treatment system of claim 149, wherein the opening defined by the split in the tubular cuff body is characterized by a first width from the first outer surface of the first section to the first outer surface of the second section, and a second width from the inner surface of the first section to the inner surface of the second section.

192. The treatment system of claim 191, wherein the first width and the second width are approximately equal or the first width exceeds the second width or the second width exceeds the first width.

193. The treatment system of claim 149, wherein the nerve comprises a cervical phrenic nerve.

194. The treatment system of claim 148, wherein the IPG is configured to control an anodecathode pair selection from the plurality of electrodes to selectively steer the stimulation current towards the motor fibers of the nerve and away from the sensory fibers of the nerve.

195. The treatment system of claim 194, wherein the IPG is configured to control the anodecathode pair selection from the plurality of electrodes based on a user- selected anode-cathode pair selection.

196. The treatment system of claim 194, wherein the IPG is configured to control the anodecathode pair selection based on sensory feedback information indicative of a sensory response by the patient to the stimulation current.

197. The treatment system of claim 196, wherein the sensory feedback information includes one or more of heart-rate information, skin-conductivity information, breathing-rate information, user-feedback information.

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