Configurations for endovascular therapy device

Abstract

An endovascular medical device system includes an expandable structure including a plurality of connected struts defining a tubular body. In some examples, the tubular body extends between a proximal end and a distal end. The endovascular medical devices system includes a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut. The endovascular medical devices system includes an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element. In some examples, the array of electrodes generally faces in a radial direction outward from the expandable structure. In some examples, the expandable structure includes a radiopaque distal extension extending distally of the tubular body and is generally circumferentially aligned with the array of electrodes. In some examples, the radiopaque distal extension is configured to indicate the radial direction of the electrodes.

Description

CONFIGURATIONS FOR ENDOVASCULAR THERAPY DEVICE

[0001] This application claims priority to, and the benefit of, U.S. Provisional Application No. 63 / 676,127, filed July 26, 2024, and entitled “CONFIGURATIONS FOR ENDOVASCULAR THERAPY DEVICE,” the entire contents of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates to electrical stimulation therapy.BACKGROUND

[0003] Medical devices, such as electrical stimulation devices, may be used in different therapeutic applications, such as vagus nerve stimulation (VNS) and / or deep brain stimulation (DBS). A medical device may be used to deliver therapy to a patient to treat a variety of symptoms or patient conditions. In some therapy systems, an external or an implantable electrical stimulator delivers electrical stimulation therapy to a target tissue site within a patient with the aid of one or more electrodes and / or senses one or more patient parameters with the aid of the one or more electrodes.SUMMARY

[0004] This disclosure describes example endovascular medical devices and systems configured to endovascularly deliver electrical stimulation therapy to a patient (e.g., to one or more nerves or brain targets) and / or sense one or more patient parameters (e.g., nerve signals, brain signals, and / or other physiological parameters), and related methods. In particular, this disclosure describes configurations for structures of medical devices and systems that facilitate delivery of electrical stimulation therapy and / or sensing patient parameters from an endovascular location.

[0005] In the examples described herein, an endovascular therapy system includes one or more electrodes and / or other sensing elements that are carried by an expandable structure at a distal portion of an elongated body (e.g., a medical lead). The expandable structure (e.g., a stent, or stent-like structure that can include a plurality of struts) is configured to transform between a delivery (e.g., compressed or relatively low-profile) configuration and a deployed (e.g., expanded) configuration. One or more electrodes and / or sensing elements are mechanically coupled to, disposed on, or otherwise carried by the expandable structure. Each electrode and / or sensing element is electrically connected to a medical device via conductor wires. The medicaldevice is configured to deliver therapy (e.g., electrical stimulation therapy) and / or received sensed signals via the electrodes or sensing elements by way of the conductor wires. The conductor wires can extend from the medical device, along the elongated body, and distal of the elongated body to electrically connect to each electrode or sensing element.

[0006] In some examples herein, the expandable structure includes structural features that facilitate visualization of the expandable structure via a suitable medical imaging modality (e.g., angiography), which can be configured to indicate a radial direction faced by the electrodes and / or sensing elements carried by the expandable structure. For example, in some examples, the expandable structure includes a radiopaque distal extension that is mechanically coupled to the expandable structure and / or extends distally of a main body portion of the expandable structure. The radiopaque distal extension can be circumferentially aligned (e.g., circumferentially aligned with respect to the expandable structure) with one or more of the electrodes and / or sensing elements, such that the radiopaque distal extension can indicate a radial direction (e.g., a radial direction outwards from a central longitudinal axis of the expandable structure) faced by one or more of the electrodes and / or sensing elements. In some examples, the radiopaque distal extension indicates a general radial direction faced by an array of electrodes and / or sensing elements that is collectively formed from multiple electrodes and / or sensing elements.

[0007] In some examples, the radiopaque distal extension of the expandable structure is configured to indicate a radial direction faced by the array of electrodes and / or sensing elements even when expandable structure is partially or completely within a delivery catheter. For example, in some examples, the radiopaque distal extension is mechanically coupled to and / or extends sufficiently distally of the expandable structure such as to enable visualization of the radial direction faced by the array of electrodes, even when the expandable structure is fully or partly within a delivery catheter, during which the expandable structure can be in a delivery (e.g., compressed) configuration. As the radial direction faced by the electrodes can otherwise be relatively more difficult to determine when the expandable structure is in the delivery (e.g., compressed) configuration, such as when a majority of the expandable structure is within (e.g., surrounded by) the delivery catheter, having the radiopaque distal extension extend sufficiently distally of the expandable structure (e.g., extend sufficiently distally of the main body portion of the expandable structure) can enable a user (e.g., a clinician) to more accurately assess the radial direction faced by electrodes before deploying the expandable structure and / or while deploying the expandable structure. Such assessment can enable a user to rotate the delivery catheter and / or the expandable structure such that electrodes face in a desired (e.g., targeted direction), such as to face one or more nerves outside of a blood vessel, before deploying expandable structure to the deployed configuration. Being able to assess the radial direction faced by an array of electrodescan also reduce instances in which a user (e.g., a clinician) must re-sheath and / or rotate the expandable structure to achieve desired placement of the array of electrodes within a bloodvessel. Additionally or alternatively, having the radiopaque distal extension extend sufficiently distally of the expandable structure (e.g., extend sufficiently distally of the main body portion of the expandable structure) can enable a user (e.g., a clinician) to more accurately assess the approximate radial direction faced by the electrodes during initial deployment (e.g., expansion) of the expandable structure, such as while the expandable structure is initially advanced distally out of the delivery catheter. For example, as the expandable structure can be configured to rapidly expand to appose a wall of the blood vessel when advanced distally of the delivery catheter, the radiopaque distal extension can extend sufficiently distally of the main body portion of the expandable structure such that a user (e.g., a clinician) can visualize and / or adjust the radial direction faced by the array of the electrodes in the early stages of deployment of the expandable structure. Such visualization and adjustment during initial deployment of the expandable structure can reduce subsequent instances of re-sheathing and re-deployment of the expandable structure, such as in cases where the radial direction faced by the array of electrodes is less than ideal during and / or after an initial deployment of the expandable structure.

[0008] In some examples herein, the expandable structure includes one or more portions (e.g., sections) configured to help anchor the expandable structure within vasculature of a patient. For example, in some examples, at least a proximal portion of the expandable structure is configured to anchor the expandable structure within the blood vessel of the patient by exerting a sufficient force (e.g., a radial force outward from a central longitudinal axis of the expandable structure) on an inner wall of a blood vessel to limit or prevent axial movement and / or rotation of the expandable structure relative to the blood vessel. In some examples, in the deployed configuration of the expandable structure, at least a proximal portion of the expandable structure defines a larger maximum outer dimension (e.g., an outer diameter) as compared to another portion of the expandable structure (e.g., a distal, electrode-carrying portion of the expandable structure), wherein the proximal portion with the larger maximum outer dimension helps anchor the expandable structure within the blood vessel of the patient. The portion of the expandable structure with the larger maximum outer dimension (e.g., the proximal portion of the expandable structure) can be configured to exert a relatively greater outward radial force (e.g., as compared to another electrode-carrying distal portion of the expandable structure), such that the relatively greater outward radial force helps to anchor the expandable structure within the blood vessel of the patient. By having a proximal portion of the expandable structure provide the majority of the anchoring force needed to anchor the expandable structure within a blood vessel, a user (e.g., a clinician) can more easily rotate the expandable structure (e.g., about a central longitudinal axis)within a blood vessel when the expandable structure is only partially deployed from a delivery catheter. For example, where only a distal portion of the expandable structure is advanced distally of the delivery catheter and permitted to expand (e.g., such that the proximal portion is still within the delivery catheter, and not expanded against a blood vessel wall), a clinician can rotate the expandable structure (e.g., about the longitudinal axis) to orient an array of electrode mechanically coupled to the expandable structure such that the array of electrodes faces a target radial direction (e.g., a target radial direction outwards from the longitudinal axis of the expandable structure).

[0009] In some examples herein, portions of the expandable structure include structural features that facilitate mechanical coupling of one or more electrodes and / or sensing elements in way that limits or prevents electrical shorting via unwanted physical contact between the one or more electrodes / sensing elements and the main body of the expandable structure. For example, in some examples, the expandable structure includes a plurality of electrode attachments (e.g., that can be connected to and / or formed by one or more struts of the expandable structure) that are sized, shaped, and / or otherwise configured to facilitate coupling of electrodes to the expandable structure in a way that limits or prevents electrical shorting between the electrodes and the body of the expandable structure (e.g., as both the electrodes and the expandable structure can include an electrically conductive material). In some examples, each respective electrode attachment element includes a projection that is configured to mechanically couple to a respective electrode, and also maintain physical separation between the respective electrode and other portions of the expandable structure (e.g., such as one or more struts of the expandable structure). Limiting and / or preventing physical contact between each respective electrode and the body of the expandable structure (e.g., including physical contact between each respective electrode and struts of the expandable structure) can prevent electrical shorting between each respective electrode and the expandable structure (e.g., such that the electrode and the expandable structure remain electrically isolated). As unwanted electrical communication between the electrode and the expandable structure can lead to less energy delivered via respective electrodes to target tissue of a patient, limiting or preventing physical contact between the electrodes and the expandable structure can ensure that little or no electrical energy delivered via the electrode is lost due to contact with the expandable structure.

[0010] In some examples herein, the endovascular therapy system includes features and / or components configurated to electrically insulate the electrodes from the expandable structure (e.g., including the electrode attachment elements). For example, the expandable structure and / or the electrode attachment elements can include one or more electrically insulative components and / or electrically insulative coatings that include electrically insulative materials that canelectrically insulate the electrodes from the expandable structure. As portions of the expandable structure can include an electrically conductive material, including one or more electrically insulative components to electrically insulate electrodes from the expandable structure can reduce or prevent energy loss due to electrical shorting between the electrodes and the expandable structure (e.g., that would otherwise be energy delivered to target tissue of a patient).

[0011] In some examples herein, the expandable structure is sized, shaped, and / or otherwise configured to limit or prevent different sections of the expandable structure from rotating with respect to other sections (e.g., wherein each section includes a portion of the expandable structure located at a particular axial location and extends around a central longitudinal axis of the expandable structure). In some examples, the expandable structure includes a plurality of struts, wherein the struts form a plurality of different sections. The sections can be connected by a plurality of connection elements. In some examples, the connection elements are sized, shaped, and otherwise configured to enable the expandable structure to be relatively flexible (e.g., able to reversibly deform in different ways without causing irreversible damage to the expandable structure). In some examples, where connection elements mechanically connect sections of the expandable structure to which one or more electrodes are attached, the connection elements are configured to limit or prevent rotation of such sections relative to each other. In some examples, each connection is rotationally symmetric and / or reflectionally symmetric, which can enable the expandable structure to expand in such a way that facilitates uniform expansion and / or extension of the expandable structure (e.g., and limits and / or prevents rotations of respective sections of the expandable structure relative to each other). In some examples, each of the connection elements are rotationally and / or reflectionally symmetric, which can limit or prevent rotation of sections of the expandable structure relative to other sections. By limiting or preventing such relative movement (e.g., rotation) between sections of the expandable structure (e.g., where each of the different sections can include electrodes), a clinician may be able to more easily align electrodes attached to the expandable structure with target tissue, even when the expandable structure is under a force (e.g., a tension force) that would otherwise cause the electrodes attached to the expandable structure to move (e.g., rotate) relative to each other.

[0012] In some examples herein, the expandable structure is sized, shaped, and / or otherwise configured to be relatively flexible without physically interfering with electrodes and / or without preventing electrodes to be attached to the expandable structure. In some examples, where electrodes are attached to the expandable structure via electrode attachment elements, portions of the expandable structure located adjacent to the electrode attachment elements are sized, shaped, and / or otherwise configured to avoid physical interference with the electrodes when the electrodes are attached to the expandable structure. For example, where the expandable structureincludes a plurality of different sections to which electrodes are attached, connection elements between such sections of the expandable structure can be sized, shaped, and / or otherwise configured to avoid physically contacting the electrodes (e.g., when the electrodes are being attached to the expandable structure and / or when the electrodes are delivering therapy and / or when the electrodes are receiving sensed signals from an endovascular location). In some examples, each of connection elements defines an s-shape, wherein a trough of the s-shape is positioned relative to a respective electrode attachment element such as to limit or prevent the connection element from physically interfering with a respective electrode mechanically coupled to the respective electrode attachment element.

[0013] In some examples herein, the expandable structure is configured to have different and / or varying levels of flexibility by at least having different ratios of connected crowns between particular adjacent sections of the expandable structure. In some examples, each section the expandable structure defines respective proximal and distal crowns that are mechanically connected to respective crowns of other sections, and the fraction of connected crowns to total crowns (e.g., where the number of total crowns equals the number of connected crowns plus the number of unconnected crowns) corresponds to a flexibility of the expandable structure (e.g., such that some sections are more flexible than others). In some examples, all respective crowns between adjacent sections are connected (e.g., otherwise referred to herein as a “closed-cell” configuration). In some examples, less than all respective crowns between adjacent sections are connected (e.g., otherwise referred to herein as a “open-cell” configuration). In some examples, for some adjacent sections (e.g., otherwise referred to herein as a pair of adjacent sections), all respective crowns between the adjacent sections connected, while for other adjacent sections, less than all respective crowns between the adjacent sections connected (e.g., otherwise referred to herein as an “hybrid-cell” configuration). Such hybrid-cell configurations of the expandable structure can enable at least some sections of the expandable structure (e.g., a distal portion) to be re-sheathed because all respective crowns of adjacent sections are connected, while other sections are relatively more flexible because less than all respective crowns between adjacent sections are connected.

[0014] In some examples, an endovascular medical device includes an expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements, the array of electrodes generally facing in a radial directionoutward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, and wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expandable structure is expanded in a blood vessel.

[0015] In some examples, a method of using a medical device system includes introducing a medical device into vasculature of a patient, the medical device including: an expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements, the array of electrodes generally facing in a radial direction outward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, and wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expandable structure is expanded in a blood vessel; and advancing the medical device until the array of electrodes are at or near a target location in the vasculature of the patient.

[0016] In some examples, an endovascular medical device includes an expandable structure configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed configuration within a blood vessel, the expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements such that when the expandable structure is in the deployed configuration, adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm, the array of electrodes generally facing in a radial direction outward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body by about 2.0 mm to about 10.0 mm, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expandable structure isexpanded in the blood vessel, and wherein when the expandable structure is in the deployed configuration, at least a proximal portion of the expandable structure is configured to anchor the expandable structure within the blood vessel.

[0017] In some examples, an endovascular medical device includes an expandable structure including a plurality of struts, the expandable structure defining a plurality of electrode attachment sections and a plurality of connection sections, each of the plurality of connection sections axially interspersed between at least two of the plurality of electrode attachment sections, wherein: each of the plurality of electrode attachment sections includes one or more electrode attachment elements configured to receive one or more electrodes, each of the plurality of connection sections includes one or more connection elements such that each of the one or more connection elements extends between and connects at least two electrode attachment sections of the plurality of electrode attachment sections, and each respective connection element of the one or more connection elements is rotationally symmetric or reflectionally symmetric about an axial midpoint of the respective connection element.

[0018] In some examples, a method of using a medical device system includes introducing a medical device into vasculature of a patient, the medical device including: an expandable structure including a plurality of struts, the expandable structure defining a plurality of electrode attachment sections and a plurality of connection sections, each of the plurality of connection sections axially interspersed between at least two of the plurality of electrode attachment sections, wherein: each of the plurality of electrode attachment sections includes one or more electrode attachment elements configured to receive one or more electrodes, each of the plurality of connection sections includes one or more connection elements such that each of the one or more connection elements extends between and connects at least two electrode attachment sections of the plurality of electrode attachment sections, and each respective connection element of the one or more connection elements is rotationally symmetric or reflectionally symmetric about an axial midpoint of the respective connection element; and advancing the medical device until the expandable structure is at or near a target location in the vasculature of the patient.

[0019] In some examples, an endovascular medical device includes an expandable structure including a plurality of struts, the expandable structure defining a plurality of electrode attachment sections and a plurality of connection sections, each of the plurality of connection sections axially interspersed between at least two of the plurality of electrode attachment sections, wherein: each of the plurality of electrode attachment sections includes one or more electrode attachment elements configured to receive one or more electrodes, each of the plurality of electrode attachment section defines a respective plurality of distal crowns and a respective plurality of proximal crowns, each of the plurality of connection sections includes one or moreconnection elements such that each of the one or more connection elements extends between and connects at least a subset of crowns of the respective plurality of distal crowns of a first respective electrode attachment section to at least a subset of crowns of the respective plurality of proximal crowns of a second respective electrode attachment of the plurality of electrode attachment sections, each respective connection element of the one or more connection elements defines and s-shape is rotationally symmetric or reflectionally symmetric about an axial midpoint of the respective connection element, and each of the one or more connection elements is configured to straighten in response to an axial force applied to the expandable structure, and the expandable structure is configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed within a blood vessel.

[0020] In some examples, an endovascular medical device includes an expandable structure including a plurality of struts and defining a longitudinal axis, wherein the expandable structure forms a plurality of sections axially disposed along the longitudinal axis including at least a first pair of axially adjacent sections and a second pair of axially adjacent sections, each section of the plurality of sections including a respective subset of struts of the plurality of struts extending around the longitudinal axis and forming a respective plurality of proximal crowns and a respective plurality of distal crowns, wherein the first pair of axially adjacent sections includes a first section and a second section, wherein at least some of the respective plurality of proximal crowns of the first section are connected to at least some of the respective plurality of distal crowns of the second section according to a first fraction of connected proximal crowns to total proximal crowns of the first section, wherein the second pair of axially adjacent sections includes a third section and a fourth section, wherein at least some of the respective plurality of proximal crowns of the third section are connected to at least some of the respective plurality of distal crowns of the fourth section according to a second fraction of connected proximal crowns to total proximal crowns of the third section, and wherein the first fraction of connected proximal crowns to total proximal crowns is greater than the second fraction of connected proximal crowns to total proximal crowns.

[0021] In some examples, a method of using a medical device system includes introducing a medical device into vasculature of a patient, the medical device including: an expandable structure including a plurality of struts and defining a longitudinal axis, wherein the expandable structure forms a plurality of sections axially disposed along the longitudinal axis including at least a first pair of axially adjacent sections and a second pair of axially adjacent sections, each section of the plurality of sections including a respective subset of struts of the plurality of struts extending around the longitudinal axis and forming a respective plurality of proximal crowns and a respective plurality of distal crowns, wherein the first pair of axially adjacent sections includesa first section and a second section, wherein at least some of the respective plurality of proximal crowns of the first section are connected to at least some of the respective plurality of distal crowns of the second section according to a first fraction of connected proximal crowns to total proximal crowns of the first section, wherein the second pair of axially adjacent sections includes a third section and a fourth section, wherein at least some of the respective plurality of proximal crowns of the third section are connected to at least some of the respective plurality of distal crowns of the fourth section according to a second fraction of connected proximal crowns to total proximal crowns of the third section, and wherein the first fraction of connected proximal crowns to total proximal crowns is greater than the second fraction of connected proximal crowns to total proximal crowns; and advancing the medical device until the expandable structure is at or near a target location in the vasculature of the patient.

[0022] In some examples, an endovascular medical device includes an expandable structure including a plurality of struts and defining a longitudinal axis, wherein the expandable structure forms a plurality of sections axially disposed along the longitudinal axis including at least a first pair of axially adjacent sections and a second pair of axially adjacent sections, each section of the plurality of sections including a respective subset of struts of the plurality of struts extending around the longitudinal axis and forming a respective plurality of proximal crowns and a respective plurality of distal crowns, wherein the first pair of axially adjacent sections includes a first section and a second section, wherein at least some of the respective plurality of proximal crowns of the first section are connected to at least some of the respective plurality of distal crowns of the second section according to a first fraction of connected proximal crowns to total proximal crowns of the first section, wherein the second pair of axially adjacent sections includes a third section and a fourth section, wherein at least some of the respective plurality of proximal crowns of the third section are connected to at least some of the respective plurality of distal crowns of the fourth section according to a second fraction of connected proximal crowns to total proximal crowns of the third section, wherein the first fraction of connected proximal crowns to total proximal crowns is greater than the second fraction of connected proximal crowns to total proximal crowns, wherein the first fraction is greater than or equal to one-half, wherein the first pair of sections including the first section and the second section are distal to all other sections of the plurality of sections, wherein for the second pair of axially adjacent sections, respective pairs of connected proximal crowns and distal crowns are evenly distributed around the expandable structure, and wherein the expandable structure is configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed configuration within a blood vessel.

[0023] The examples described herein may be combined in any permutation or combination.

[0024] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. l is a conceptual diagram illustrating an example therapy system including an endovascular device configured to deliver electrical stimulation therapy to a target tissue site of a patient and / or sense a patient parameter from an endovascular location.

[0026] FIG. 2 is a functional block diagram illustrating components of an example medical device of the therapy system of FIG. 1.

[0027] FIG. 3 A illustrates a distal portion of an example endovascular therapy system including an expandable structure and electrodes carried by the expandable structure.

[0028] FIG. 3B illustrates a distal portion of an example endovascular therapy system including an expandable structure and electrodes carried by the expandable structure being advanced distally of a delivery catheter.

[0029] FIG. 4A and FIG. 4B illustrate an example expandable structure.

[0030] FIG. 5 A illustrates an example expandable structure.

[0031] FIG. 5B illustrates an example expandable structure.

[0032] FIG. 6A and FIG. 6B illustrate an example electrode attachment element.

[0033] FIG. 7 illustrates an example electrode attachment element.

[0034] FIG. 8 illustrates an example expandable structure.

[0035] FIG. 9 illustrates an example expandable structure.

[0036] FIG. 10 illustrates an example expandable structure.

[0037] FIG. 11 illustrates an example connection element of an expandable structure.

[0038] FIG. 12 illustrates an example connection element of an expandable structure.

[0039] FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D, FIG. 13E, FIG. 13F, FIG. 13G, and FIG.13H illustrate example electrode layout configurations.

[0040] FIG. 14 illustrates an example expandable structure.

[0041] FIG. 15 is a flow diagram illustrating an example technique for introducing and advancing an endovascular device according to this disclosure.

[0042] Like reference characters denote like elements throughout the description and figures.DETAILED DESCRIPTION

[0043] This disclosure describes devices, systems, and methods relating to delivery of electrical stimulation therapy, such as vagus nerve stimulation (VNS) or deep brain stimulation (DBS), and / or sensing of one or more patient parameters (e.g., nerve activity from one more nerves, cardiac signals, muscle activation signals, brain signals and / or other physiological parameters, such as impedance, electroencephalogram (EEG), evoked potentials, local field potentials, etc.) from an endovascular location. Example endovascular locations that can be used for electrical stimulation therapy (e.g., VNS therapy) and / or sensing using the devices described herein include an internal jugular vein (IJV). Example endovascular locations that can be used to access the brain sites for electrical stimulation therapy (e.g., DBS) and / or sensing using the devices described herein include any suitable cranial blood vessel (also referred to herein as a cerebral blood vessel or neurovasculature, which can include a vein or an cranial artery), such as, but not limited to, the thalamostriate vein, the internal cerebral vein, the basal vein of Rosenthal, the inferior sagittal sinus, the superior sagittal sinus, or the anterior choroidal artery.

[0044] VNS has been proposed for use to manage one or more patient conditions, such as to control an inflammatory response in patients. Stimulating the vagus nerve may dampen the inflammatory response and associated cytokine response. In some examples, inflammatory cytokines are modulated up or down via stimulation. In addition, VNS may assist in stroke rehabilitation and limit ischemia reperfusion injury. After a myocardial infarct or stroke, reperfusion therapies (surgery or drugs) are given to restore blood flow. However, due to the restoration of blood, flow induced local damage occurs, including ischemia reperfusion injury. This injury may induce local accumulations of chemical mediators such as reactive oxygen species (ROS) production, inflammatory cytokines, bradykinin, etc., which can further affect inflammation. Such inflammatory compounds may trigger sensory signaling, which can lead to a reduced organ vagus activity and sympathetic overdrive. Vagus nerve stimulation may treat reperfusion damage as the inflammatory state may be lowered by increasing parasympathetic drive.

[0045] DBS has been proposed for use to manage one or more patient conditions. For example, DBS can be used to alleviate, and in some cases eliminate, symptoms associated with movement disorders, other neurodegenerative impairment, seizure disorders, psychiatric disorders (e.g., mood disorders), or the like. Movement disorders may be found in patients with Parkinson’s disease, multiple sclerosis, and cerebral palsy, among other conditions, and can be associated with disease or trauma. DBS can be delivered to one or more target sites in a brain of a patient to help a patient with muscle control and minimize movement problems, such as rigidity,bradykinesia (i.e., slow physical movement), rhythmic hyperkinesia (e.g., tremor), nonrhythmic hyperkinesia (e.g., tics) or akinesia (i.e., a loss of physical movement).

[0046] In the case of seizure disorders, DBS can be delivered to one or more target sites in a brain of a patient to reduce the frequency or severity of seizures, or even help prevent the occurrence of seizures. In the case of psychiatric disorders, DBS can be delivered to help minimize or even eliminate symptoms associated with major depressive disorder (MDD), bipolar disorder, anxiety disorders, post-traumatic stress disorder, dysthymic disorder, or obsessive- compulsive disorder (OCD). DBS can also reduce the symptoms of Parkinson’s disease, dystonia, or cerebellar outflow tremor.

[0047] While this disclosure is primarily directed to examples of VNS and / or sensing via applicable endovascular locations (e.g., the internal jugular vein), it should be understood that the devices, systems, and techniques may be adapted for DBS, other kinds of brain stimulation, peripheral nerve stimulation, or electrical stimulation and / or sensing of any nerve tissue that can be done via an endovascular location.

[0048] In the examples described herein, an endovascular therapy system includes one or more electrodes and / or other sensing elements that are carried by an expandable structure at a distal portion of an elongated body (e.g., a medical lead). The expandable structure (e.g., a stent, or stent-like structure) is configured to transform between a delivery (e.g., compressed or relatively low-profile) configuration and a deployed (e.g., expanded) configuration. One or more electrodes and / or sensing elements are mechanically coupled to, disposed on, or otherwise carried by the expandable structure. Each electrode and / or sensing element is electrically connected to a medical device via conductor wires. The medical device is configured to deliver therapy (e.g., electrical stimulation therapy) and / or received sensed signals via the electrodes by way of the conductor wires. The conductor wires may extend along, be a part of, incorporated into, and / or integrally formed as part of the elongated body (e.g., the medical lead). In some examples, conductor wires extend along (e.g., within) the elongated body (e.g., such as from a proximal portion of the elongated body to a location distal of the elongated body) to electrically connect each electrode or sensing element to the medical device.

[0049] In some examples herein, the expandable structure includes structural features that facilitate visualization of the expandable structure via a suitable medical imaging modality (e.g., angiography), which can be configured to indicate a radial direction faced by the electrodes and / or sensing elements carried by the expandable structure. For example, in some examples, the expandable structure includes a radiopaque distal extension that is mechanically coupled to the expandable structure and / or extends distally of a main body portion of the expandable structure. The radiopaque distal extension can be circumferentially aligned (e.g., circumferentially alignedwith respect to the expandable structure) with one or more of the electrodes and / or sensing elements, such that the radiopaque distal extension can indicate a radial direction (e.g., a radial direction outwards from a central longitudinal axis of the expandable structure) faced by one or more of the electrodes and / or sensing elements. In some examples, the radiopaque distal extension indicates a general radial direction faced by an array of electrodes and / or sensing elements that is collectively formed from multiple electrodes and / or sensing elements.

[0050] In some examples, the radiopaque distal extension of the expandable structure is configured to indicate a radial direction faced by the array of electrodes and / or sensing elements even when expandable structure is partially or completely within a delivery catheter. For example, in some examples, the radiopaque distal extension is mechanically coupled to and / or extends sufficiently distally of the expandable structure such as to enable visualization of the radial direction faced by the array of electrodes, even when the expandable structure is fully or partly within a delivery catheter, during which the expandable structure can be in a delivery (e.g., compressed) configuration. As the radial direction faced by the electrodes can otherwise be relatively more difficult to determine when the expandable structure is in the delivery (e.g., compressed) configuration, such as when a majority of the expandable structure is within (e.g., surrounded by) the delivery catheter, having the radiopaque distal extension extend sufficiently distally of the expandable structure (e.g., extend sufficiently distally of the main body portion of the expandable structure) can enable a user (e.g., a clinician) to more accurately assess the radial direction faced by electrodes before deploying the expandable structure and / or while deploying the expandable structure. Such assessment can enable a user to rotate the delivery catheter and / or the expandable structure such that electrodes face in a desired (e.g., targeted direction), such as to face one or more nerves outside of a blood vessel, before deploying expandable structure to the deployed configuration. Being able to assess the radial direction faced by an array of electrodes can also reduce instances in which a user (e.g., a clinician) must re-sheath and / or rotate the expandable structure to achieve desired placement of the array of electrodes within a bloodvessel. Additionally or alternatively, having the radiopaque distal extension extend sufficiently distally of the expandable structure (e.g., extend sufficiently distally of the main body portion of the expandable structure) can enable a user (e.g., a clinician) to more accurately assess the approximate radial direction faced by the electrodes during initial deployment (e.g., expansion) of the expandable structure, such as while the expandable structure is initially advanced distally out of the delivery catheter. For example, as the expandable structure can be configured to rapidly expand to appose a wall of the blood vessel when advanced distally of the delivery catheter, the radiopaque distal extension can extend sufficiently distally of the main body portion of the expandable structure such that a user (e.g., a clinician) can visualize and / or adjust theradial direction faced by the array of the electrodes in the early stages of deployment of the expandable structure. Such visualization and adjustment during initial deployment of the expandable structure can reduce subsequent instances of re-sheathing and re-deployment of the expandable structure, such as in cases where the radial direction faced by the array of electrodes is less than ideal during and / or after an initial deployment of the expandable structure.

[0051] In some examples herein, the expandable structure includes one or more portions (e.g., sections) configured to help anchor the expandable structure within vasculature of a patient. For example, in some examples, at least a proximal portion of the expandable structure is configured to anchor the expandable structure within the blood vessel of the patient by exerting a sufficient force (e.g., a radial force outward from a central longitudinal axis of the expandable structure) on an inner wall of a blood vessel to limit or prevent axial movement and / or rotation of the expandable structure relative to the blood vessel. In some examples, in the deployed configuration of the expandable structure, at least a proximal portion of the expandable structure defines a larger maximum outer dimension (e.g., an outer diameter) as compared to another portion of the expandable structure (e.g., a distal, electrode-carrying portion of the expandable structure), wherein the proximal portion with the larger maximum outer dimension helps anchor the expandable structure within the blood vessel of the patient. The portion of the expandable structure with the larger maximum outer dimension (e.g., the proximal portion of the expandable structure) can be configured to exert a relatively greater outward radial force (e.g., as compared to another electrode-carrying distal portion of the expandable structure), such that the relatively greater outward radial force helps to anchor the expandable structure within the blood vessel of the patient. By having a proximal portion of the expandable structure provide the majority of the anchoring force needed to anchor the expandable structure within a blood vessel, a user (e.g., a clinician) can more easily rotate the expandable structure (e.g., about a central longitudinal axis) within a blood vessel when the expandable structure is only partially deployed from a delivery catheter. For example, where only a distal portion of the expandable structure is advanced distally of the delivery catheter and permitted to expand (e.g., such that the proximal portion is still within the delivery catheter, and not expanded against a blood vessel wall), a clinician can rotate the expandable structure (e.g., about the longitudinal axis) to orient an array of electrode mechanically coupled to the expandable structure such that the array of electrodes faces a target radial direction (e.g., a target radial direction outwards from the longitudinal axis of the expandable structure).

[0052] In some examples herein, portions of the expandable structure include structural features that facilitate mechanical coupling of one or more electrodes and / or sensing elements in way that limits or prevents electrical shorting via unwanted physical contact between the one ormore electrodes / sensing elements and the main body of the expandable structure. For example, in some examples, the expandable structure includes a plurality of electrode attachments (e.g., that can be connected to and / or formed by one or more struts of the expandable structure) that are sized, shaped, and / or otherwise configured to facilitate coupling of electrodes to the expandable structure in a way that limits or prevents electrical shorting between the electrodes and the body of the expandable structure (e.g., as both the electrodes and the expandable structure can include an electrically conductive material). In some examples, each respective electrode attachment element includes a projection that is configured to mechanically couple to a respective electrode, and also maintain physical separation between the respective electrode and other portions of the expandable structure (e.g., such as one or more struts of the expandable structure). Limiting and / or preventing physical contact between each respective electrode and the body of the expandable structure (e.g., including physical contact between each respective electrode and struts of the expandable structure) can prevent electrical shorting between each respective electrode and the expandable structure (e.g., such that the electrode and the expandable structure remain electrically isolated). As unwanted electrical communication between the electrode and the expandable structure can lead to less energy delivered via respective electrodes to target tissue of a patient, limiting or preventing physical contact between the electrodes and the expandable structure can ensure that little or no electrical energy delivered via the electrode is lost due to contact with the expandable structure.

[0053] In some examples herein, the endovascular therapy system includes features and / or components configurated to electrically insulate the electrodes from the expandable structure (e.g., including the electrode attachment elements). For example, the expandable structure and / or the electrode attachment elements can include one or more electrically insulative components and / or electrically insulative coatings that include electrically insulative materials that can electrically insulate the electrodes from the expandable structure. As portions of the expandable structure can include an electrically conductive material, including one or more electrically insulative components to electrically insulate electrodes from the expandable structure can reduce or prevent energy loss due to electrical shorting between the electrodes and the expandable structure (e.g., that would otherwise be energy delivered to target tissue of a patient).

[0054] In some examples herein, the expandable structure is sized, shaped, and / or otherwise configured to limit or prevent different sections of the expandable structure from rotating with respect to other sections (e.g., wherein each section includes a portion of the expandable structure located at a particular axial location and extends around a central longitudinal axis of the expandable structure). In some examples, the expandable structure includes a plurality of struts, wherein the struts form a plurality of different sections. The sections can be connected by aplurality of connection elements. In some examples, the connection elements are sized, shaped, and otherwise configured to enable the expandable structure to be relatively flexible (e.g., able to reversibly deform in different ways without causing irreversible damage to the expandable structure). In some examples, where connection elements mechanically connect sections of the expandable structure to which one or more electrodes are attached, the connection elements are configured to limit or prevent rotation of such sections relative to each other. In some examples, each connection is rotationally symmetric and / or reflectionally symmetric, which can enable the expandable structure to expand in such a way that facilitates uniform expansion and / or extension of the expandable structure (e.g., and limits and / or prevents rotations of respective sections of the expandable structure relative to each other). In some examples, each of the connection elements are rotationally and / or reflectionally symmetric, which can limit or prevent rotation of sections of the expandable structure relative to other sections. By limiting or preventing such relative movement (e.g., rotation) between sections of the expandable structure (e.g., where each of the different sections can include electrodes), a clinician may be able to more easily align electrodes attached to the expandable structure with target tissue, even when the expandable structure is under a force (e.g., a tension force) that would otherwise cause the electrodes attached to the expandable structure to move (e.g., rotate) relative to each other.

[0055] In some examples herein, the expandable structure is sized, shaped, and / or otherwise configured to be relatively flexible without physically interfering with electrodes and / or without preventing electrodes to be attached to the expandable structure. In some examples, where electrodes are attached to the expandable structure via electrode attachment elements, portions of the expandable structure located adjacent to the electrode attachment elements are sized, shaped, and / or otherwise configured to avoid physical interference with the electrodes when the electrodes are attached to the expandable structure. For example, where the expandable structure includes a plurality of different sections to which electrodes are attached, connection elements between such sections of the expandable structure can be sized, shaped, and / or otherwise configured to avoid physically contacting the electrodes (e.g., when the electrodes are being attached to the expandable structure and / or when the electrodes are delivering therapy and / or when the electrodes are receiving sensed signals from an endovascular location). In some examples, each of connection elements defines an s-shape, wherein a trough of the s-shape is positioned relative to a respective electrode attachment element such as to limit or prevent the connection element from physically interfering with a respective electrode mechanically coupled to the respective electrode attachment element.

[0056] In some examples herein, the expandable structure is configured to have different and / or varying levels of flexibility by at least having different ratios of connected crownsbetween particular adjacent sections of the expandable structure. In some examples, each section the expandable structure defines respective proximal and distal crowns that are mechanically connected to respective crowns of other sections, and the fraction of connected crowns to total crowns (e.g., where the number of total crowns equals the number of connected crowns plus the number of unconnected crowns) corresponds to a flexibility of the expandable structure (e.g., such that some sections are more flexible than others). In some examples, all respective crowns between adjacent sections are connected (e.g., otherwise referred to herein as a “closed-cell” configuration). In some examples, less than all respective crowns between adjacent sections are connected (e.g., otherwise referred to herein as a “open-cell” configuration). In some examples, for some adjacent sections (e.g., otherwise referred to herein as a pair of adjacent sections), all respective crowns between the adjacent sections connected, while for other adjacent sections, less than all respective crowns between the adjacent sections connected (e.g., otherwise referred to herein as an “hybrid-cell” configuration). Such hybrid-cell configurations of the expandable structure can enable at least some sections of the expandable structure (e.g., a distal portion) to be re-sheathed because all respective crowns of adjacent sections are connected, while other sections are relatively more flexible because less than all respective crowns between adjacent sections are connected.

[0057] In some examples, a medical device is configured to generate electrical stimulation and / or sense a patient parameter via the electrodes of the endovascular device. The electrodes may be carried by or otherwise disposed on an expandable structure, which may be configured to orient the electrodes and / or anchor the electrodes at a particular location in the vasculature of the patient.

[0058] FIG. 1 is a conceptual diagram illustrating an example therapy system 10 configured to deliver electrical stimulation therapy to a target tissue site of a patient 12 or sense a patient parameter from an endovascular location. Patient 12 ordinarily will be a human patient. In some cases, however, therapy system 10 is applied to other mammalian or non-mammalian non-human patients. Therapy system 10 includes a medical device 14 and an endovascular device 16. In the example shown in FIG. 1, medical device 14 is configured to deliver electrical stimulation therapy (e.g., VNS) to a vagus nerve 21 of patient 12 and / or sense bioelectric signals via electrodes 17. However, in other examples, therapy system 10 and / or medical device 14 is configured to deliver electrical stimulation therapy (e.g., DBS) to brain 18 of patient 12 and / or sense bioelectrical brain signals in brain 18 via electrodes 17.

[0059] In the example of FIG. 1, endovascular device 16 is positioned in a jugular vein 13 of patient 12 such that one or more electrodes 17 are located proximate to a target tissue site. In particular, electrodes 17 are positioned to deliver electrical stimulation therapy to and / or sensesignals from nerves surrounding jugular vein 13, including (but not limited to) vagus nerve 21. Endovascular device 16 includes an expandable structure 19 at a distal portion 15 of endovascular device 16 which may help hold electrodes 17 in apposition with a vessel wall (e.g., of jugular vein 13). In some examples, as discussed in relation to later examples, expandable structure 19 is mechanically coupled (e.g., directly mechanically coupled) to a portion of endovascular device 16 via a suitable mechanical connection (e.g., welding, crimped connection, or the like). Medical device 14 can provide electrical stimulation to one or more regions surrounding jugular vein 13 in order to manage a condition of patient 12, such as to mitigate the severity or duration of the patient condition.

[0060] Endovascular device 16 includes any suitable medical device configured to deliver electrical stimulation signals to tissue proximate electrodes 17. For example, endovascular device16 can be a medical lead, a catheter, a guidewire, or another elongated body carrying electrodes17 and configured to be electrically coupled to medical device 14 via an electrically conductive pathway (e.g., via one or more conductor wires) that runs between medical device 14 and electrodes 17. Endovascular device 16 has any suitable length that enables connection to medical device 14 either directly or indirectly, e.g., a length of 150 centimeters (cm) to 250 cm, such as 200 cm. Further, endovascular device 16 has a suitable length (e.g., as measured along a longitudinal axis of endovascular device 16) for accessing a target tissue site within the patient from a vascular access point. In examples in which endovascular device 16 accesses the jugular vein 13 and / or vasculature in a brain 18 of patient 12 from a femoral artery access point at the groin of the patient, endovascular device 16 has a length of about 100 cm to about 200 cm, although other lengths may be used. However, other access points may be used to introduce endovascular device 16 into vasculature of a patient, such as, but not limited to, a radial artery.

[0061] As used herein, “about” can indicate the exact value or nearly the exact value to the extent permitted by manufacturing tolerances. “About” can also refer to a certain percentage of the recited value (e.g., within about 1%, 5%, or 10%).

[0062] Endovascular device 16 is configured to be introduced in the vasculature of patient 12, such as to access jugular vein 13 and / or relatively more distal locations in a patient, such as the middle cerebral artery (MCA) in a brain of a patient. Endovascular device 16 may include an elongated body that is structurally configured to be relatively flexible, pushable, and relatively kink- and buckle-resistant, so that it may resist buckling when a pushing force is applied to a relatively proximal portion to advance endovascular device 16 distally through vasculature, and so that it may resist kinking when traversing around a tight turn in the vasculature. Kinking and / or buckling of may hinder a clinician’s efforts to push the elongated body distally, e.g., past aturn. In some examples, endovascular device 16 includes one or more radiopaque components (e.g., platinum bands) proximate electrodes 17 and / or expandable structure 19.

[0063] Instead of or in addition to the elongated body of endovascular device 16 being configured for intravascular navigation to a cerebral blood vessel to deliver electrical stimulation therapy or sense a patient parameter, endovascular device 16 can be navigated through vasculature (e.g., to jugular vein 13, brain 18, or other target tissue sites) with the aid of a guide member. The guide member can include an outer catheter, an inner catheter, a guide extension catheter, a guidewire, or the like or combination thereof.

[0064] In some examples, more than one of endovascular device 16 is introduced into, positioned in, and / or implanted within patient 12 to provide stimulation to and / or sense multiple anatomical regions, including one or more of both the left and right jugular veins, as well as in locations of brain 18. For example, two or more of endovascular device 16, which may be paired with one or more of medical device 14, may be configured of bilateral stimulation and / or sensing (e.g., of the left jugular vein and a right jugular vein). Endovascular device 16, including electrodes 17 and / or expandable structure 19, can be positioned in and / or implanted within a blood vessel for chronic therapy delivery and / or chronic sensing (e.g., on the order of months or even years) or for more temporary therapy delivery and / or sensing (e.g., on the order of days, such as less than a month or less than 6 months). Temporary therapy delivery may include one or more trial periods, such as to determine, evaluate, or confirm an efficacy of stimulation and / or sensing, and / or to select electrical stimulation parameters for chronic therapy delivery.

[0065] The electrical stimulation therapy described herein (e.g., VNS, DBS, or the like) may be used to treat various patient conditions, such as, a variety of illnesses including, but not limited to: reperfusion damage, cardiac ischemia, brain ischemia, stroke, traumatic brain injury, surgical or non-surgical acute kidney injury, inability of the intestine (bowel) to contract normally and move waste out of the body, postoperative ileus, postoperative cognitive decline or postoperative delirium, asthma, sepsis, bleeding control, myocardial infarction reduction, dysmotility, obesity, movement disorders, other neurodegenerative impairment, seizure disorders, psychiatric disorders (e.g., mood disorders). Treating any of these diseases may improve patient outcomes by shortening length of hospital stays and reducing medical costs.

[0066] The vasculature into which endovascular device 16 may be inserted and / or guided includes, but is not limited to, veins or arteries. For example, endovascular device 16 can be navigated from a vasculature access site (e.g., in the femoral artery, the radial artery, or another suitable access site) to one or more of a jugular vein (e.g., internal jugular vein and / or external jugular vein), a carotid artery (e.g., internal carotid artery, external carotid artery, and / or common carotid artery), as well as brain targets including the thalamostriate vein, the internal cerebralvein, the basal vein of Rosenthal, the inferior / superior sagittal sinus, the anterior choroidal artery, or any related combinations thereof.

[0067] A clinician can also select a particular blood vessel to position electrodes 17 within, such as to avoid certain regions to minimize or even eliminate adverse effects. For example, electrodes 17 can be oriented or positioned relative to vagus nerve 21 to avoid inadvertently providing electrical stimulation to anatomical regions (e.g., undesired anatomical regions) near the targeted anatomical region.

[0068] In some examples, endovascular device 16 is configured to be delivered to one or more target sites in vasculature of patient 12. Thus, rather than introducing endovascular device 16 into tissue in close proximity with vagus nerve 21 through an incision in the neck or chest area of patient 12, endovascular device 16 is configured to be navigated proximate to a target electrical stimulation site and / or sensing site via vasculature of patient 12. The endovascular delivery of endovascular device 16 to target sites can help minimize the invasiveness of therapy system 10.

[0069] In some examples, one or more electrodes 17 are positioned on (e.g., mechanically coupled to, defined by, or otherwise carried by) expandable structure 19 of endovascular device16, which is configured to expand radially outwards from a relatively low-profile (e.g., radially compressed) delivery configuration to a deployed configuration. This may enable electrodes 17 to be held in apposition with a blood vessel wall, promote tissue ingrowth around electrodes 17 along the vessel wall (while still leaving a patent lumen to enable blood flow through the blood vessel, through expandable structure 19, despite implantation of endovascular device 16), which can reduce the overall power needed to deliver efficacious electrical stimulation therapy to a target tissue site, and help secure electrodes 17 in place in the blood vessel for chronic therapy delivery.

[0070] Medical device 14 can be an external medical device or an implantable medical device that includes electrical stimulation circuitry configured to generate and deliver electrical stimulation therapy to patient 12 and / or sensing circuitry configured to sense a patient parameter (e.g., a physiological signal) via one or more electrodes 17 of endovascular device 16. Electrodes17, when activated by medical device 14, can be configured to deliver electrical stimulation and / or sense a patient parameter from an endovascular location. In the example shown in FIG. 1, endovascular device 16 is directly or indirectly mechanically and electrically coupled to medical device 14 via a header 11 of medical device 14, which defines a plurality of electrical contacts in one or more feedthrough portions (e.g., that are configured to electrically couple electrodes 17 to electrical stimulation generation circuitry and / or sensing circuitry within medical device 14).

[0071] In some examples, therapy system 10 includes one or more conductor wires (not shown in FIG. 1) extending between medical device 14 and electrodes 17, the one or more conductor configured to carry electrical signals between medical device and electrodes 17 or vice versa. The conductor wires may extend along, be a part of, incorporated into, and / or integrally formed as part of endovascular device 16. In some examples, header 11 includes multiple feedthrough portions, which may be respectively configured for receiving one of multiple portions of endovascular device 16. Header 11 may also be referred to as a connector block or connector of medical device 14. Endovascular device 16 may be mechanically coupled and / or electrically coupled to header 11 with the aid of a lead extension. However, in some examples, a lead extension is not used between header 11 and endovascular device 16, and endovascular device is directly mechanically and / or electrically connected to medical device 14 via header 11.

[0072] In some examples, medical device 14 is configured to be positioned in (e.g., implanted in) patient 12 in any suitable location, such as a location in a pectoral region. In other examples, medical device 14 is configured to be external to patient 12. Endovascular device 16 may be, for example, implanted within a vein (e.g., jugular vein 13) and one or more proximal wires / leads can remain within the venous system until they exit the venous system, such as through the subclavian vein in the chest or the internal jugular vein in the neck for implant in the pectoral region. In yet other examples, some or all of medical device 14 is configured to be implanted in the vasculature, e.g., as part of endovascular device 16.

[0073] As shown in FIG. 1, system 10 may also include a programmer 20, which may be a handheld device, portable computer, or workstation that provides a user interface to a user, for example a clinician or other user, such as a patient. The user may interact with the user interface to program electrical stimulation parameters for medical device 14.

[0074] With the aid of programmer 20 or another computing device, a clinician may select values for therapy parameters for controlling therapy delivery by therapy system 10. The values for the therapy parameters may be organized into a group of parameter values referred to as a “therapy program” or “therapy parameter set.” “Therapy program” and “therapy parameter set” are used interchangeably herein. In the case of electrical stimulation, the therapy parameters may include a combination of activated electrodes 17 (also referred to herein as an electrode combination), a power, and an amplitude, which may be a current or voltage amplitude, and, if medical device 14 delivers electrical pulses, a pulse width, and a pulse rate for stimulation signals to be delivered to the patient. Other example therapy parameters include a slew rate, duty cycle, and phase of the electrical stimulation signal.

[0075] An electrode combination may include a selected subset of one or more electrodes 17 located on one or more of endovascular devices 16 mechanically coupled and / or electricallycoupled to medical device 14. The electrode combination may also refer to the polarities of the electrodes in the selected subset. By selecting particular electrode combinations (e.g., of activated ones of electrodes 17), a user may target particular tissue sites (e.g., anatomic structures) within patient 12. In addition, by selecting values for slew rate, duty cycle, phase amplitude, pulse width, and / or pulse rate, the user can attempt to generate an efficacious therapy for patient 12 that is delivered via the selected electrode subset.

[0076] Whether programmer 20 is configured for clinician or patient use, programmer 20 may be configured to communicate with medical device 14 or any other computing device via wireless or a wired communication. Programmer 20, for example, may communicate via wireless communication with medical device 14 using radio frequency (RF) telemetry techniques. Programmer 20 may also communicate with another programmer or computing device via a wired or wireless connection using any of a variety of local wireless communication techniques, such as RF communication according to the 802.11 or Bluetooth specification sets, infrared communication according to the Infrared Data Association (IRDA) specification set, or other standard or proprietary telemetry protocols. Programmer 20 may also communicate with another programming or computing device via a wired or wireless communication technique.

[0077] In some examples, in addition to or instead of delivering electrical stimulation to a target location (e.g., vagus nerve 21), medical device 14 or another device is configured to sense one or more patient parameters, such as bioelectric signals, either using electrodes 17 or other types of sensing elements that are carried by endovascular device 16. Bioelectric signals (also referred to herein as bioelectrical signals) can be sensed, and indications of sensed signals can be used by clinicians to make clinically relevant decision. In other examples, sensed bioelectric signals are used as part of continuous feedback system in which medical device 14 adjusts one or more therapy parameter values based on sensed bioelectrical signals. Example bioelectric signals are described in further detail below with reference to FIG. 2.

[0078] In some examples, medical device 14 is configured to generate and deliver a suitable electrical stimulation signal, which can be a continuous time signal (e.g., a sinusoidal waveform or the like) or a plurality of pulses. In some examples, the electrical stimulation waveform generated by medical device 14 and delivered by one or more of electrodes 17 is a charge balanced, biphasic waveform. In some examples, such an electrical stimulation waveform consists of periodic pulses or otherwise include periodic pulses, or can include a continuous time waveform.

[0079] As noted above, in some examples, one or more electrodes 17 are positioned on expandable structure 19. In some examples, one or more sensing elements that are different from electrodes 17 are positioned on the same expandable structure (e.g., expandable structure 19) asone or more electrodes 17 or on a different expandable structure (e.g., a structure similar to or different from expandable structure 19) of endovascular device 16. Expandable structure 19 can have any suitable configuration that enables endovascular device 16 to assume a relatively low- profile configuration (also referred to herein as a “delivery” or “compressed” configuration in some examples) to facilitate delivery through vasculature to a target tissue site and expand radially outwards (relative to a central longitudinal axis of endovascular device 16) to position the one or more electrodes 17 closer to target tissue.

[0080] In some examples, expandable structure 19 is configured to expand radially outwards with sufficient force and to a cross-sectional dimension (e.g., a diameter) sufficient to position the one or more electrodes 17 in apposition with a blood vessel wall. Positioning one or more electrodes 17 in apposition with a blood vessel wall may help promote tissue ingrowth around electrodes 17, which can reduce the impedance and the overall power needed to deliver efficacious electrical stimulation therapy to a target tissue site, and help secure electrodes 17 in place in the blood vessel for chronic (e.g., on the order of months or even years) therapy delivery. Fixing endovascular device 16 in place within the blood vessel via the tissue ingrowth or, in some examples, using another fixation structures / anchoring mechanisms, such as tines, coils, barbs, or the like, can also help reduce the possibility of thrombosis.

[0081] Expandable structure 19 can be configured to expand radially outwards using any suitable technique and configuration. In some examples, expandable structure 19 includes a shape memory (e.g., nitinol) material that enables expandable structure 19 to assume a predetermined shape in the absence of a force (e.g., a compressive or tensile force) holding expandable structure 19 in a relatively low-profile delivery configuration. For example, expandable structure 19 can be configured to expand (e.g., self-expand) radially outwards upon deployment from an outer sheath (e.g., an outer catheter), or upon the proximal withdrawal of a straightening element (e.g., a guidewire or a mandrel) positioned in an inner lumen of the endovascular device 16. In some examples, expandable structure 19 is configured to expand radially outwards in response to proximal movement of a pull member attached to a distal portion of the endovascular device 16, in response to a distal movement of an elongated control member attached to the expandable structure, or with the aid of a balloon or the like.

[0082] Expandable structure 19 can have any suitable configuration in its deployed (e.g., expanded) configuration. In some examples herein, expandable structure 19 includes a plurality of connected struts to form a structure (e.g., a tubular structure with a tubular body) configured to expand radially outward (e.g., from a central longitudinal axis of expandable structure 19). For example, expandable structure 19 can include a tubular member, a basket, include one or more splines or arms configured to expand radially outwards, define one or more loops, define ahelical or spiral element, or the like or combinations thereof, when in the deployed configuration. One or more expandable structures 19 may be disposed at various positions along endovascular device 16 (e.g., at one or more longitudinal positions along endovascular device 16). Expandable structure 19 can be formed from a plurality of structural elements (e.g., braided or mechanically coupled together) or can be a unitary structure (e.g., a laser cut nitinol tube). In some examples, expandable structure 19 is referred to herein as having a stent-like structure.

[0083] Expandable structure 19 can be mechanically coupled to a portion of endovascular device 16 (e.g., distal portion 15 of endovascular device 16). In some examples, expandable structure 19 is mechanically coupled to endovascular device 16 via a welded connection, a crimped connection, a bonded connection (e.g., via an adhesive and / or another suitable bonding agent), or another suitable mechanical connection. In some examples herein, the mechanical connection between expandable structure 19 endovascular device 16 can facilitate a reduced mechanical load on and / or reduced mechanical fatigue of various components of therapy system 10. For example, the mechanical connection between expandable structure 19 endovascular device 16 can facilitate a reduced mechanical load on and / or reduced mechanical fatigue of one or more conductor wires (not shown in FIG. 1) extending between electrodes 17 and medical device 14.

[0084] In addition to, or instead of, chronic therapy delivery and / or chronic sensing, example devices, systems, and methods described herein can be used for more temporary applications. In some examples, a first endovascular device (e.g., configured like endovascular device 16 or having another configuration) is configured to be operated in an acute (e.g., temporary) trial mode for a trial period to determine, evaluate, or confirm an efficacy of stimulation and / or sensing. For example, endovascular device 16 (as well as electrodes 17, medical device 14, processing circuitry, etc.) may be configured to operate in the trial mode to determine the efficacy of one or more stimulation parameter values and / or one or more sensing parameters. After the acute trial period, the first endovascular device may be removed, and a second endovascular device (e.g., configured like endovascular device 16 or having another configuration) configured to operate in a chronic mode may be implanted for a chronic period for chronic (e.g., long term, or permanent) stimulation therapy or sensing. In some examples, a first endovascular device (e.g., for use in the acute trial mode) is configured to be implanted and subsequently removed after the trial period.

[0085] A trial period has a shorter intended duration as compared to a chronic period, though the ultimate length of the chronic period may be less than an intended duration due to one or more factors, such as a patient response that requires shortening the chronic period relative to the intended duration of the chronic period. In some examples, the trial period includes a trial periodlength on the order of minutes (e.g., 1 minute, 2 minutes, 3 minutes, 5 minutes, 30 minutes, 45 minutes, etc.), on the order of hours (e.g., 1 hour, 2 hours, 5 hours, 12 hours, etc.), on the order of days (e.g., 1 day, 2 days, 3 days, etc.), on the order of weeks (e.g., 1 week, 2 weeks, 3 weeks, etc.) on the order of months (e.g., 1 month, 2 months, 3 months, etc.), or longer. In some examples, one or more of endovascular devices may be used for multiple trial periods (e.g., successive trial periods) for determining an efficacy of one or more stimulation parameters and / or one or more sensing parameters.

[0086] Therapy system 10 may have any suitable configuration for delivering electrical stimulation to a target tissue site in patient 12 or sensing a patient parameter from an endovascular location (e.g., jugular vein 13). In some examples, therapy system 10 includes a first subset of electrodes of electrodes 17 configured for delivering electrical stimulation therapy and a second subset of electrodes of electrodes 17 configured to for sensing one or more patient parameters. In some examples, some or all electrodes of electrodes 17 are configured for both electrical stimulation therapy and for sensing one or more patient parameters. Therapy system 10 can include any suitable number of electrodes 17 and / or combination of different kinds of electrodes. In some examples, electrodes 17 include electrodes formed via one or more manufacturing processes. For example, electrodes 17 can include a first electrode type (e.g., an electrode configured for delivery of electrical stimulation therapy), a second electrode type (e.g., an electrode configured to sensing a signal), or any suitable combination thereof.

[0087] FIG. 2 is a functional block diagram illustrating components of an example medical device 14, which is configured to generate and deliver electrical stimulation therapy to patient 12 and, in some examples, sense one or more patient parameters, such as bioelectrical signals or other physiological parameter of patient 12. Medical device 14 includes processing circuitry 30, memory 32, therapy generation circuitry 34, sensing circuitry 36, telemetry circuitry 38, and power source 40.

[0088] Therapy generation circuitry 34 includes any suitable configuration (e.g., hardware) configured to generate and deliver electrical stimulation signals to target tissue (e.g., vagus nerve 21) in patient 12. Processing circuitry 30 is configured to control therapy generation circuitry 34 to generate and deliver electrical stimulation therapy via electrodes 17 of endovascular device 16. The therapy parameter values may be selected based on the patient condition being addressed, as well as the target tissue site in patient 12 for the electrical stimulation therapy. The electrical stimulation therapy can be provided via stimulation signals of any suitable form, such of stimulation pulses or continuous-time signals (e.g., sine waves).

[0089] Sensing circuitry 36 is configured to sense a physiological parameter of a patient. Sensing circuitry 36 may include any sensing hardware configured to sense a physiologicalparameter of a patient, such as, but not limited to, one or more electrodes, optical receivers, pressure sensors, or the like. The one or more sensing electrodes can be the same or different from electrodes 17 configured to deliver electrical stimulation therapy. In some examples, processing circuitry 30 stores the sensed physiological parameters in memory 32 or transmits the sensed parameters to another device via telemetry circuitry 38. In addition, in some examples, processing circuitry 30 can use the sensed physiological signals to control therapy delivery by therapy generation circuitry 34, e.g., the timing of the therapy delivery or one or more characteristics (e.g., parameters values) of the electrical simulation signal generated by therapy generation circuitry 34.

[0090] In some examples, sensing circuitry 36 is configured to sense a bioelectrical signal, which otherwise may be referred to as a patient parameter, via one or more electrodes 17 (e.g., all or a subset of electrodes 17). Thus, electrodes 17 can be configured to receive or transmit energy (e.g., current). In some examples, such as those in which electrodes 17 are placed proximate vagus nerve 21 (FIG. 1), example bioelectrical signals include muscle activation signals (e.g., laryngeal muscle activation), electrocardiogram (ECG), intracardiac electrogram (EGM), electromyogram (EMG). In other examples, such as those in which electrodes 17 are placed in or otherwise proximate brain 18, example bioelectrical signals include brain signals such as an EEG signal, an electrocorticogram (ECoG) signal, a signal generated from measured field potentials within one or more regions of brain 18, action potentials from single cells within brain 18 (referred to as “spikes”), or evoked potentials. Determining action potentials of single cells within brain 18 may require resolution of bioelectrical signals to the cellular level and provides fidelity for fine movements, i.e., a bioelectrical signal indicative of fine movements (e.g., slight movement of a finger).

[0091] In examples in which endovascular device 16 is configured to sense an evoked potential, endovascular device 16 may also be configured to generate a stimulus (e.g., via therapy generation circuitry 34, alone or in combination with processing circuitry 30) to elicit the evoked potential. For example, endovascular device 16 can generate and deliver electrical stimulation to tissue in brain 18 and sense an evoked compound action potential (ECAP). An ECAP is synchronous firing of a population of neurons which occurs in response to the application of a stimulus including, in some cases, an electrical stimulus by endovascular device 16. The ECAP may be detectable as being a separate event from the stimulus itself, and the ECAP may reveal characteristics of the effect of the stimulus on the tissue.

[0092] In some examples, sensing circuitry 36 and / or processing circuitry 30 includes signal processing circuitry configured to perform any suitable analog conditioning of the sensed physiological signals. For example, sensing circuitry 36 may communicate to processingcircuitry 30 an unaltered (e.g., raw) signal. Processing circuitry 30 may be configured to modify a raw signal to a usable signal by, for example, filtering (e.g., low pass, high pass, band pass, notch, or any other suitable filtering), amplifying, performing an operation on the received signal (e.g., taking a derivative, averaging), performing any other suitable signal conditioning (e.g., converting a current signal to a voltage signal), or any combination thereof. In some examples, the conditioned analog signals are processed by an analog-to-digital converter of processing circuitry 30 or other component to convert the conditioned analog signals into digital signals. In some examples, processing circuitry 30 operates on the analog or digital form of the signals to separate out different components of the signals. In some examples, sensing circuitry 36 and / or processing circuitry 30 performs any suitable digital conditioning of the converted digital signals, such as low pass, high pass, band pass, notch, averaging, or any other suitable filtering, amplifying, performing an operation on the signal, performing any other suitable digital conditioning, or any combination thereof. Additionally or alternatively, sensing circuitry 36 may include signal processing circuitry to modify one or more raw signals and communicate to processing circuitry 30 one or more modified signals.

[0093] In some examples, processing circuitry 30, alone or in combination with therapy generation circuitry 34 and / or sensing circuitry 36, is configured to operate medical device 14 (including electrodes 17, endovascular device 16, etc.) in a trial mode for a trial period to determine an efficacy of electrical stimulation or sensing. As described above, a trial mode can include a trial period of stimulation and / or sensing to determine, evaluate, or confirm an efficacy of stimulation and / or sensing. In some examples, processing circuitry 30, alone or in combination with therapy generation circuitry 34 and / or sensing circuitry 36, is configured to deliver electrical stimulation therapy and / or sense a patient parameter during the trial period. In some examples, processing circuitry 30 is configured to determine, evaluate, or confirm an efficacy of stimulation and / or sensing. For example, processing circuitry 30 may determine one or more therapy parameters for chronic stimulation and / or sensing based on the trial period.

[0094] Although shown as part of medical device 14 in FIG. 2, in other examples, sensing circuitry 36 is part of a device separate from medical device 14. For example, sensing circuitry 36 can be part of an implantable sensing device implanted in patient 12.

[0095] Processing circuitry 30, as well as other processors, processing circuitry, controllers, control circuitry, and the like, described herein, may include any combination of integrated circuitry, discrete logic circuity, analog circuitry, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or field-programmable gate arrays (FPGAs). In some examples, processing circuitry 30 includes multiple components, such as any combination of one or more microprocessors, one or more DSPs, one or moreASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry, and / or analog circuitry.

[0096] Memory 32 is configured to store program instructions, such as software, which may include one or more program modules, which are executable by processing circuitry 30. When executed by processing circuitry 30, such program instructions may cause processing circuitry 30 to provide the functionality ascribed to processing circuitry 30 herein. The program instructions may be embodied in software and / or firmware. Memory 32 may include any volatile, nonvolatile, magnetic, optical, or electrical media, such as a random access memory (RAM), readonly memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media.

[0097] Processing circuitry 30 is configured to control telemetry circuitry 38 to send and receive information. Telemetry circuitry 38, as well as telemetry modules in other devices described herein, such as programmer 20 (FIG. 1), may accomplish communication by any suitable communication techniques, such as RF communication techniques. In addition, telemetry circuitry 38 may communicate with external medical device programmer 20 via proximal inductive interaction of medical device 14 with programmer 20. Accordingly, telemetry circuitry 38 may send information to external programmer 20 on a continuous basis, at periodic intervals, or upon request from medical device 14 or programmer 20.

[0098] Power source 40 is configured to deliver operating power to various components of medical device 14. Power source 40 may include a small rechargeable or non-rechargeable battery and a power generation circuit to produce the operating power. Recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within medical device 14. In some examples, power requirements may be small enough to allow medical device 14 to utilize patient motion and implement a kinetic energy-scavenging device to trickle charge a rechargeable battery. In other examples, traditional batteries may be used for a limited period of time.

[0099] In some examples, endovascular device 16 is configured to be a standalone electrical stimulation device and can include one or more elements of medical device 14 shown in FIG. 2.

[0100] FIG. 3 A and FIG. 3B illustrate an example endovascular therapy system 100, which is an example of therapy system 10 of FIG. 1. FIG. 3 A illustrates a side view of endovascular therapy system 100, and FIG. 3B illustrates a perspective view of therapy system 100 positioned in a blood vessel 130. Endovascular therapy system 100 includes a medical lead 160 and an expandable structure 190 at a distal portion 150 of medical lead 160. As shown in FIG. 3 A, endovascular therapy system 100 includes at least electrode 170A, electrode 170B, electrode 170C, and electrode 170D, collectively referred to and shown as electrodes 170. Medical lead160, expandable structure 190, distal portion 150, and electrodes 170 are examples of endovascular device 16, expandable structure 19, distal portion 15, and electrodes 17 of FIG. 1, respectively. Blood vessel 130, shown in connection with FIG. 3B, is an example of jugular vein 13 of FIG. 1.

[0101] Medical lead 160 can have any suitable configuration, and may be configured according to the description of endovascular device 16 of FIG. 1. In some examples, medical lead 160 includes an elongated body (e.g., a tubular body defining a lumen) extending between an elongated body proximal end (not show in the examples of FIG. 3 A and FIG. 3B) and an elongated body distal end 164.

[0102] In some examples, medical lead 160 includes a suitable biocompatible polymer material. For example, medical lead 160 can include a thermoplastic material, such as Polycarbonate Urethane (PCU). In some examples, medical lead additionally or alternatively includes one or more of Polyurethane (PUR or PU), Polyethylene (PE), Polypropylene (PP), Poly etheretherketone (PEEK), Polyphenyl sulfone (PPSU or PPSF), Polypropylene (PP), Nylon, Polyester, Polyethlene Terephthalate (PET), Polymethyl Methacrylate (PMMA), Polysulfone (PSU), and / or another suitable material.

[0103] In some examples, medical lead 160 is configured to be at least partially introduced into, positioned in, and / or implanted within vasculature (e.g., blood vessel) of patient 12. In some examples, medical lead 160 includes an electrically insulative material covering at least some portions of medical lead 160 (e.g., one of the materials listed above). The electrically insulative material covering at least some portions of medical lead 160 can electrically insulate elements disposed within medical lead medical lead 160 (e.g., electrically insulate electrically conductive components, such as conductor wires 166, from blood or other tissue, such as when medical lead 160 is positioned in or advanced through a blood vessel of patient 12).

[0104] In the example of FIG. 3 A and FIG. 3B, therapy system 100 includes a plurality of conductor wires 166, wherein each conductor wire is configured to electrically connect one or more of electrodes 170 to a medical device (e.g., medical device 14 of FIG. 1). Each of conductor wires 166 can extend along (e.g., within) at least a portion of medical lead 160. In some examples, some or all of conductor wires 166 are part of medical lead 160, while in other examples, some or all of conductor wires 166 are separate components from medical lead 160.

[0105] In some examples, at least a portion of each of conductor wires 166 are housed by the insulative material of medical lead 160. For example, each of conductor wires 166 can extend within a lumen of medical lead 160. In some examples, insulative material of medical lead 160 is configured to electrically insulate portions of conductor wires 166 that run along the length of medical lead 160. As shown in the example of FIG. 3 A, each of conductor wires 166 can extenddistally of medical lead 160, such as to branch out to mechanically connect and / or electrically connect to one or more of electrodes 170. In some examples, each of conductor wires 166 extends along at least a portion of expandable structure 190.

[0106] In some examples, some or all of conductor wires 166 include a material or combination of materials configured to facilitate relatively high flexibility, high axial extensibility, and / or high fatigue resistance. For example, one or more wires of conductor wires 166 includes a beta-titanium alloy. In some examples, the beta-titanium alloy comprises a Ti- 15Mo alloy. Certain beta-titanium alloys, including Ti-15Mo alloy and similar titanium alloys enable higher wire count coils (e.g., twelve wire or greater, including equal to or greater than sixteen wire coils), such as for situations in which a relatively high number of individually controlled electrodes are needed in a small space including nerve stimulation and / or sensing from endovascular locations. In some examples, one or more of conductor wires 166 includes a core material (e.g., a core at a radial center of each wire). The core material can be configured to enhance mechanical robustness. In some examples, the core material includes tantalum.

[0107] In some examples, each of conductor wires 166 can individually and / or collectively be configured to maintain mechanical robustness (e.g., avoid fatigue), even during navigation of endovascular therapy system 100 through a vascular of a patient (e.g., patient 12), deployment of expandable structure 190, and / or long-term or short-term implantation in the presence of blood in vasculature of patient 12. For example, in some examples, at least a portion of conductor wires 166 form a multi -wire coil. By forming a multi -wire coil, individual conductor wires 166 may be relatively less prone to mechanical fatigue during bending, axial extension, axial compression, and / or other forces applied to conductor wires 166.

[0108] In some examples, conductor wires 166 include one or more coatings. In some examples, a coating applied to conductor wires 166 includes one or more of an antithrombotic (also referred to as antithrombogenic) coating (e.g., to prevent or eliminate the incidence of thrombosis), an electrically insulative coating, a slip coat (e.g., hydrophilic coating), or a suitable combination thereof.

[0109] In some examples, each of conductor wires 166 are electrically connected to respective electrode electrodes 170A-170D. In some examples, each of electrodes 170A-170D is configured to receive and / or otherwise mechanically couple to one or more conductor wires of conductor wires 166 (e.g., to facilitate the electrical connection between each of conductor wires 166 and one or more of electrodes 170). For example, each of electrodes 170A-170D can define one or more conductor holes configured to receive one or more conductor wires 166, such as for electrically coupling respective electrodes to a medical device (e.g., medical device 14 of FIG. 1). The holes in each of electrodes 170 (e.g., that are configured for receiving and / or electricallyconnecting to one or more conductor wires 166) can extend partially or entirely though each of electrodes 170. Electrodes 170 can include an electrical contact portion configured to facilitate electrical connection to conductor wires 166.

[0110] In some examples, more than one of electrodes 170 are electrically connected to a common conductor wire of conductor wires 166 (e.g., some of electrodes 170 can be “shorted” together). For example, one of conductor wires 166 can be configured to connect to a least a first electrode and a second electrode of electrodes 170 (e.g., such that a medical device 14 can simultaneously control each of the first electrode and the second electrode of electrodes 170 together). Shorting of at least some of electrodes 170 can facilitate control of multiple electrodes at the same time (e.g., for delivery of electrical stimulation therapy and / or sensing).

[0111] Expandable structure 190 as shown in FIG. 3 A and FIG. 3B is an example of expandable structure 19 as discussed in connection with FIG. 1, and can include any suitable shape and materials. In some examples, expandable structure 190 is mechanically coupled to medical lead 160 (e.g., at a distal portion of medical lead 160). Expandable structure 190 can have any suitable configuration for positioning electrodes 170 for delivering stimulation therapy and / or sensing one or more patient parameters of patient 12 from an endovascular location. In some examples, as shown in FIG. 3 A, expandable structure 190 includes a tubular body portion extending between a tubular body proximal end 190A and tubular body distal end 190B. In some examples, as shown in the FIG. 3 A and FIG. 3B, expandable structure 190 includes a plurality of connected struts 192 (shown individually as strut 192A, strut 192B, strut 192C, . . ., strut 192N, but collectively referred to herein as struts 192). In some examples, expandable structure 190 defines a lumen. In some examples, struts 192 are connected to form the tubular (e.g., stent-like) structure.

[0112] In some examples, electrodes 170 are carried by expandable structure 190, and expandable structure 190 is configured to position and / or orient electrodes 170 within vasculature of a patient (e.g., patient 12 of FIG. 1). In some examples, at least some of electrodes 170 are carried by and / or mechanically connected to struts 192 of expandable structure 190. In some examples, electrodes 170 are carried by and / or disposed on expandable structure 190, and expandable structure 190 is configured to transform from a relatively low-profile delivery configuration to a deployed (e.g., expanded) configuration in a blood vessel of a patient (e.g., within jugular vein 13 of patient 12 as discussed in relation to FIG. 1 and / or within a cranial blood vessel of patient 12). In the deployed configuration, expandable structure 190 can be configured to position the electrodes 170 to deliver electrical stimulation to tissue or sense a patient parameter from a location within a blood vessel (e.g., blood vessel 130 in the example of FIG. 3B).

[0113] In some examples, expandable structure 190 is configured to expand (e.g., selfexpand and / or via an expansion mechanism such as a balloon) radially outward. In some examples, expandable structure 190 defines a central longitudinal axis 111 (e.g., such that central longitudinal axis 111 extends through a radial center of expandable structure 190). In some examples, expandable structure 190 is configured to expand radially outward relative to central longitudinal axis 111 to a deployed configuration, such as to position electrodes 170 into apposition with a blood vessel wall (e.g., for delivering electrical stimulation therapy to tissue of patient 12 proximate the blood vessel and / or sensing a patient parameter from a location within the blood vessel). For example, expandable structure 190 can include one or more of a selfexpanding structure, including one or more of a self-expanding stent, a self-expanding coil, or another suitable expandable structure that includes one or more struts as described herein. In some examples, expandable structure 190 is at least partially self-expanding (e.g., expandable structure 190 can be partially self-expanding at least to a first maximum outer dimension, and subsequently expanded to second, larger maximum outer dimension via a balloon or another suitable expansion mechanism).

[0114] Expandable structure 190 can each include suitable configurations for mechanically coupling to and / or carrying one or more electrodes of electrodes 170. In some examples, expandable structure 190 includes structural features configured to facilitate mechanical coupling of electrodes 170 to expandable structure 190, as well as orient electrodes 170 with respect to expandable structure 190. In some examples, one or more of struts 192 are configured to mechanically couple one or more electrodes 170. In addition to or instead of struts 192, in some examples, expandable structure 190 includes other structures (e.g., weld pads, projections, apertures, and / or other structural features) configured to receive, mechanically couple to, or otherwise carry one or more of electrodes 170.

[0115] In the example of FIG. 3 A, expandable structure 190 includes structural features to facilitate mechanical coupling of electrodes 170 to expandable structure 190 as well as orient electrode 170 with respect to expandable structure 190. As shown in FIG. 3 A, expandable structure 190 includes electrode attachment element 194A, electrode attachment element 194B, electrode attachment element 194C, electrode attachment element 194D, and electrode attachment element 194E, collectively referred to herein as electrode attachment elements 194. Each electrode attachment element 194A-194E is configured to mechanically couple to one or more of electrode 170 and orient one or more of orient electrodes 170 with respect to expandable structure 190. For example, each electrode attachment element 194A-194E may be configured to mechanically couple to one or more of electrodes 170 and orient electrodes 170 such that an electrically conductive portion of each of electrode 170 faces (e.g., points) radially outward fromexpandable structure 190 (e.g., away from central longitudinal axis 111). In examples in which electrodes 170 include an electrically insulative portion, each electrode attachment element 194A-194E may be configured to orient electrodes 170 such that the electrically insulative portion faces radially inward from expandable structure 190 (e.g., towards central longitudinal axis 111).

[0116] In some examples, each electrode attachment element 194A-194E is configured to minimize rotation (e.g., reduce or even eliminate rotation) of a given electrode of electrodes 170 around one or more of struts 192 (e.g., by fixing an orientation of a given one of electrodes 170 with respect to one or more of struts 192). For example, electrode attachment elements 194 can be configured to prevent an electrically conductive portion of electrodes 170 from facing radially inward relative to expandable structure 190 (e.g., towards central longitudinal axis 111) and away from a blood vessel wall (e.g., away from a wall of jugular vein 13 as discussed with respect to FIG. 1).

[0117] Expandable structure 190 includes any suitable number of electrode attachment elements 194 that can be configured to mechanically couple electrodes 170 to expandable structure 190. As shown in the example of FIG. 3 A, expandable structure 190 includes five electrode attachment elements 194. However, expandable structure 190 can include any suitable number of electrode attachment elements 194 (e.g., one, two, three, four, five, six, seven, eight, nine, ten, twelve, fifteen, twenty, thirty, etc.). In some examples, expandable structure 190 includes more electrode attachment elements than electrodes 170 that are eventually affixed to expandable structure 190, such that expandable structure 190 can be pre-fabricated, and a suitable number, configuration, and pattern of electrodes 170 can subsequently be attached to expandable structure 190 (e.g., depending on the end use of endovascular therapy system 100). In some of these examples, not all the electrode attachment elements 194 of a given expandable structure 190 will be used to mechanically couple electrodes 170 to expandable structure 190, but some electrode attachment elements 194 will remain unattached to electrodes 170 after all of the desired number of electrodes 170 are coupled to expandable structure 190.

[0118] Expandable structure 190 can include electrode attachment elements 194 at multiple circumferential positions around expandable structure 190 (e.g., around central longitudinal axis 111) and / or multiple axial positions along expandable structure 190 (e.g., spaced apart along central longitudinal axis 111). Although referred to as circumferential positions, in some examples, expandable structure 190 is not circular in cross-section (the cross-section being taken in a direction orthogonal to central longitudinal axis 111). In such examples, the circumferential positions may still refer to the rotational position about central longitudinal axis 111).

[0119] Longitudinal spacing and / or circumferential spacing between electrode attachment elements 194 can correspond to desired longitudinal spacing and / or circumferential spacing between electrodes 170 for therapeutically effective endovascular stimulation and / or sensing once expandable structure 190 is in a deployed configuration.

[0120] Electrode attachment elements 194 can each include suitable configurations for being received by and / or otherwise mechanically coupling to one or more electrodes of electrodes 170. Similarly, electrodes 170 can include a suitable configuration for mechanically receiving and / or otherwise mechanically coupling to electrode attachment elements 194. In some examples, as shown in the example of FIG. 3 A with respect to electrode attachment element 194E, each electrode attachment element 194A-194E includes at least one projection 196 configured to be received by one of electrodes 170 and / or an intermediate component that is mechanically coupled to one of electrodes 170. As shown in the example of FIG. 3 A, projection 196 for electrode attachment element 194E branches off of strut 192A. In some examples, projection 196 is configured to mechanically couple to mating portions of one or more of electrodes 170. In some examples, each respective electrode 170 defines one or more structural features (e.g., blind holes, through holes, lumens, weld pads, and / or the like) configured to facilitate mechanical coupling to a respective projection 196 of a given electrode attachment element 194A-194E. For example, in some examples, electrode attachment element 194A-194E includes projection 196, which can be configured to be inserted into a structural feature (e.g., a lumen, hole, and / or the like) defined by each respective one of electrodes 170. As shown in the example of FIG. 3 A, each of electrodes 170A-170D is disposed on a respective projection 196 of electrode attachment elements 194A- 194D.

[0121] As shown in the example of FIG. 3 A, each of electrode attachment elements 194A- 194E is connected to a respective strut of struts 192. In some examples, each respective projection 196 of electrode attachment elements 194A-194E is formed (e.g., integrally formed) as part of a unitary structure of expandable structure 190 along with connected struts 192. In some examples, expandable structure 190, including connected struts 192 and electrode attachment elements 194, is a single, continuous structure. For example, expandable structure 190, including connected struts 192 and / or electrode attachment elements 194, can be laser-cut from a single piece of material (e.g., nitinol, or another metallic material).

[0122] In other examples, electrode attachment elements 194 (e.g., which each can include the at least one projection 196) are formed separately from expandable structure 190, and subsequently attached to expandable structure 190. For example, electrode attachment elements 194 can be separately formed and attached to respective struts of struts 192 (e.g., electrode attachment element 194E including project 196 is formed separately from expandable structure190 and subsequently attached to strut 192A of expandable structure 190). When formed separately from expandable structure 190, electrode attachment elements 194 can include a different material as expandable structure 190 (e.g., of struts 192), and / or different dimensions (e.g., cross-sectional dimensions) as struts 192.

[0123] While the example of FIG. 3 A shows each electrode attachment elements 194 having one projection 196, electrode attachment elements 194 can include more than one projection 196 (e.g., two projections, three projections, four projections, five projections), such as to couple to respective mating portions of one or more of electrodes 170. Multiple of projection 196 can facilitate mechanical connection of one or more electrodes 170 to expandable structure 190 as described in this disclosure. In some examples, electrode attachment elements 194 include a corresponding number of projections 196 as respective mating structural features (e.g., holes and / or other structural features) on a respective one of electrodes 170 and / or an intermediate component that is mechanically coupled to one of electrodes 170. In some examples, each of the multiple projections 196 of a given one of electrode attachment elements 194 facilitate mechanical coupling of multiple electrodes 170 to the given one of electrode attachment elements 194.

[0124] Projection 196 of each electrode attachment elements 194A-194E can include any suitable configuration to facilitate mechanical coupling of electrodes 170 to expandable structure 190. In the example of FIG. 3 A, electrode attachment elements 194A-194E are longitudinally spaced apart long expandable structure 190 (e.g., along central longitudinal axis 111) such that the respective projection 196 of each of electrode attachment elements 194A-194E branches off of different struts of struts 192A-192N. That is, projection 196 of each of electrode attachment elements 194 branch off of different struts of struts 192A-192N.

[0125] Expandable structure 190 can also be configured to orient electrodes 170 to face radially outward from central longitudinal axis 111 (e.g., when expandable structure 190 is in the deployed configuration). In some examples, expandable structure 190 is configured to position electrodes 170 in apposition with a blood vessel wall (e.g., after therapy system 100 including expandable structure 190 is advanced proximate to a target location in the vasculature of a patient, such as patient 12 of FIG. 1 and deployed). For example, electrodes 170 may face radially outward at an orientation that is sufficient to deliver or sense electrical signals (e.g., deliver electrical signals to or sense electrical signals from nerves surrounding a blood vessel).

[0126] Endovascular therapy system 100, including expandable structure 190, may be configured to have a relatively low-profile configuration to facilitate delivery and / or placement into relatively narrow and / or tortuous vessels. Once proximate a target location, expandable structure 190 can be configured to transform to the deployed configuration (e.g., to position theone or more of electrodes 170 to deliver electrical stimulation to tissue of patient 12 or sense a patient parameter from a location within the blood vessel). In some examples, when expandable structure 190 is in a deployed configuration, electrodes 170 are flush or nearly flush with an outer surface of expandable structure 190. In some examples, expandable structure 190 is configured to position electrodes 170 such that at least one surface of each of electrodes 170 is flush or nearly flush with the outer surface of expandable structure 190 (e.g., when expandable structure 190 is in the deployed configuration).

[0127] In some examples, as shown in the example of FIG. 3B, endovascular therapy system 100 includes a delivery catheter 142, which can be configured for delivering expandable structure 190 and electrodes 170 to a target location with blood vessel 130 of a patient. For example, delivery catheter 142 can define a lumen 143 configured to receive one or more of medical lead 160 and / or expandable structure 190 with electrodes 170 therethrough. In some examples, delivery catheter 142 is configured to constrain expandable structure 190 in the delivery (e.g., compressed) configuration, such that expandable structure with electrodes 170 can be introduced into vasculature of a patient (e.g., patient 12 of FIG. 1) and navigated to a target location within the vasculature of patient 12 (e.g., blood vessel 130, which can be an example of jugular vein 13 of FIG. 1). In some examples, lumen 143 extends to a distal end 144 of delivery catheter 142, such that at least expandable structure 190 with electrodes 170 can be delivered distally of distal end 144 of delivery catheter 142.

[0128] Endovascular therapy system 100 can include any suitable number of electrodes 170 for delivery of stimulation therapy (e.g., electrical stimulation therapy) and / or sensing from an endovascular location. While the example of FIG. 3 A and FIG. 3B illustrate endovascular therapy system as including four of electrodes 170, endovascular therapy system 100 can include any suitable number of electrodes 170 (e.g., one electrode, two electrodes, three electrodes, four electrodes, five electrodes, six electrodes, seven electrodes, eight electrodes, nine electrodes, ten electrodes, twelve electrodes, fifteen electrodes, twenty electrodes, thirty electrodes, etc.). Each of electrodes 170 can be disposed at respective spaced-apart locations along and / or around expandable structure 190.

[0129] Expandable structure 190 can include electrodes 170 at multiple circumferential positions around expandable structure 190 and / or multiple longitudinal positions along expandable structure 190 (e.g., spaced apart along central longitudinal axis 111). Longitudinal spacing and / or circumferential spacing between electrodes 170 can correspond to desired longitudinal spacing and / or circumferential spacing between electrode 170 for therapeutically effective endovascular stimulation and / or sensing.

[0130] In some examples, each of electrodes 170 together collectively form an array of electrodes 170. In some examples, each of electrodes 170 in the electrode array generally face outward in a common radial direction (e.g., in a common radial direction outward from central longitudinal axis 111 of expandable structure 190). For example, as shown in the example of FIG. 3B, array of electrodes 170 faces in radial direction 133 (e.g., where radial direction 133 faces radially outward from central longitudinal axis 111 of expandable structure 190 toward a wall of blood vessel 130). Although array of electrodes 170 can subtend an arc 131 around the circumference of expandable structure 190, as shown in the example of FIG. 3B, the general radial direction faced by electrodes 170 is radial direction 133 (e.g., which may be a radial direction faced by a circumferential center of array of electrodes 170 relative to expandable structure 190).

[0131] At least some of electrodes 170 that form array of electrodes 170 can be spaced apart by suitable distances (e.g., axial distances in a direction along expandable structure 190 as well as circumferential distances in a direction around expandable structure 190), such as to effectuate nerve stimulation and / or sensing from an endovascular location. In some examples, at least some axially adjacent electrodes 170 are spaced apart by about 5.0 mm to about 7.0 mm (e.g., between respective axial centers of the respective axially adjacent electrodes 170), such as about 6.0 mm. For example, in the example of FIG. 3A, electrode 170A and electrode 170B are axially adjacent electrodes, and can spaced apart by about 5.0 mm to about 7.0 mm, such as about 6.0 mm (e.g., as measured in an axial and / or longitudinal direction along expandable structure 190, such as in a direction parallel to central longitudinal axis 111). In some examples, at least some circumferentially adjacent electrodes 170 are spaced apart by about 5.0 mm to about 7.0 mm (e.g., between respective circumferential centers of the respective axially adjacent electrodes 170 with respect to expandable structure 190), such as about 6.0 mm. For example, electrode 170A and electrode 170C are circumferentially adjacent electrodes, and can be spaced apart by about 5.0 mm to about 7.0 mm, such as about 6.0 mm (e.g., as measured in a circumferential direction around expandable structure 190, such as in a direction transverse to central longitudinal axis 111). Such axial and circumferential spacing described herein can be sufficient as to effectively stimulate and / or sense a nerve surrounding blood vessel 130, even though expandable structure 190 is disposed with blood vessel 130. Such stimulation and / or sensing from an endovascular location may require relatively more energy and / or sensitivity of electrodes (e.g., as compared to instances of nerve stimulation and / or sensing from a non-endovascular location).

[0132] In some examples herein, array of electrodes 170 include different groups of electrodes 170, wherein different groups of electrodes 170 are axially spaced apart and / or circumferentially spaced apart, such as to effectuate nerve stimulation and / or sensing from anendovascular location. For example, array of electrodes 170 can include multiple groups electrodes 170 (e.g., wherein each group includes two or more of electrodes 170). In some examples, groups of electrodes 170 are disposed at respective axial locations, wherein the electrodes of the respective groups are not axially spaced apart. In some examples, groups of electrodes 170 are disposed at respective circumferential locations, wherein the electrodes of the respective groups are not circumferentially spaced apart. The total number of groups of electrodes 170 and number of electrodes 170 within each group of electrodes 170 can correspond to a number of channels of an existing medical device used for stimulation and / or sensing to which electrodes 170 are electrically connected. For example, some eight-channel medical devices may enable use of eight electrodes, and such that a suitable configuration of electrodes 170 can include four groups of axially spaced apart electrodes 170 and two groups of circumferentially spaced apart electrodes 170 (e.g., where each group includes at least two electrodes 170, but a given group can be associated with both axially and circumferentially spaced apart groups).

[0133] Any suitable number of groups of electrodes 170, and any suitable number of electrodes within a given group of electrodes 170, can be used (e.g., one or more electrodes per group). In some examples, array of electrodes 170 includes at least two groups of electrodes 170 axially spaced apart along expandable structure 190 (e.g., such as two, three, four, five, ten, or another suitable number of groups of electrodes 170 axially spaced apart along expandable structure 190). In some examples, array of electrodes 170 includes at least two groups of electrodes 170 circumferentially spaced apart along expandable structure 190 (e.g., such as two, three, four, five, ten, or another suitable number of groups of electrodes 170 circumferentially spaced apart along expandable structure 190). In some examples, axially adjacent groups of electrodes 170 are spaced apart by a suitable distance (e.g., such as spaced apart by about 5.0 mm to about 7.0 mm, such as about 6.0 mm). In some examples, circumferentially adjacent groups of electrodes 170 are spaced apart by a suitable distance (e.g., such as spaced apart by about 5.0 mm to about 7.0 mm, such as about 6.0 mm).

[0134] In some examples, expandable structure 190 is configured to be rotated (e.g., by a clinician, within the vasculature of patient 12 as described with respect to FIG. 1) to position the electrode array (e.g., including electrodes 170) to face toward a target location and / or anatomical structure (e.g., toward vagus nerve 21 in the example of FIG. 1).

[0135] Electrodes 170 can be fabricated using any suitable method. In some examples, electrodes 170 are formed from a suitable machining (milling, turning, grinding, or electrical discharge machining) and / or stamping process. Electrodes 170 can be formed separately from, and subsequently mechanically coupled to, expandable structure 190. In such examples,electrodes 170 may be manufactured using relatively inexpensive or high precision techniques that do not require accommodating other structures, such as expandable structure 190. In other examples, electrodes 170 are integrally formed with expandable structure 190.

[0136] In some examples, one or more elements of therapy system 100 are configured to facilitate positioning of electrodes 170 at the target site (e.g., via radiographic and / or radiopaque portions that indicate a positioning of electrodes 170). For example, therapy system 100 can include a radiographic or radiopaque marker to indicate an axial position and / or circumferential position of one or more of electrodes 170 along and / or around longitudinal axis 111. In some examples, at least a portion of therapy system 100 is aligned with one or more of electrodes 170 (and / or circumferentially aligned an array of electrodes formed from a group of electrodes 170) to indicate a direction (e.g., a radial direction) faced by electrodes 170. In some examples, therapy system 100 (e.g., one or more components of therapy system 100) includes a radiographic marker that is circumferentially aligned with one or more of electrodes 170 and / or an array of electrodes 170. For example, one or more of medical lead 160 and / or expandable structure 190 (or sub-components thereof) includes a radiographic or radiopaque material circumferentially aligned with electrodes 170 and configured to indicate a radial direction (e.g., a radial direction outwards from central longitudinal axis 111) faced by electrodes 170 (e.g., when expandable structure 190 is in the deployed configuration).

[0137] In some examples, expandable structure 190 includes a radiopaque distal extension 198 extending distally from tubular body distal end 190B of the tubular body of expandable structure 190. In some examples, radiopaque distal extension 198 is generally circumferentially aligned with one or more of electrode attachment elements 194A-194E around expandable structure 190 (e.g., such that radiopaque distal extension 198 is positioned circumferentially around expandable structure 190 at a similar circumferential location as one or more or one or more of electrode attachment elements 194A-194E). In some examples, as shown in the examples of FIG. 3 A and FIG. 3B, radiopaque distal extension 198 is generally circumferentially aligned with array of electrodes 170 (e.g., when array of electrodes 170 is mechanically coupled to expandable structure 190 via electrode attachment elements 194). In some examples, at least a portion of radiopaque distal extension 198 includes a radiopaque or radiographic material that is visible via a suitable medical imaging modality (e.g., fluoroscopy). In some examples, at least a distal-most portion of radiopaque distal extension 198 includes the radiopaque or radiographic material.

[0138] In some examples, radiopaque distal extension 198 is configured to indicate a radial direction of (e.g., faced by) electrodes 170 (e.g., radial direction 133 as shown in the example of FIG. 3B). For example, as shown in the example of FIG. 3B, when expandable structure 190 is atleast partially expanded in blood vessel 130, radiopaque distal extension 198 is circumferentially aligned with array of electrodes 170 such as to indicate radial direction 133 faced by array of electrodes 170. Although array of electrodes 170 can subtend arc 131 around the circumference of expandable structure 190, as shown in the example of FIG. 3B, the general radial direction faced by electrodes 170 is radial direction 133 (e.g., which may be a radial direction faced by a circumferential center of array of electrodes 170 relative to expandable structure 190).

[0139] In some examples, radiopaque distal extension 198 is configured to indicate radial direction 133 faced by array of electrodes 170 even when expandable structure is partially or completely within delivery catheter 142. For example, radiopaque distal extension 198 is mechanically coupled to and / or extends sufficiently distally of expandable structure 190 such as to enable visualization of a radial direction faced by array of electrodes 170, even when expandable structure 190 is fully or partly within delivery catheter 142, during which expandable structure 190 can be in a delivery (e.g., compressed) configuration. As the radial direction faced by array of electrodes 170 can be relatively more difficult to determine when expandable structure 190 is in the delivery (e.g., compressed) configuration, such as when a majority of expandable structure 190 is within (e.g., surrounded by) delivery catheter 142, having radiopaque distal extension 198 extend sufficiently distally of expandable structure 190 (e.g., extend sufficiently distally of the main body portion of expandable structure 190) can enable a user (e.g., a clinician) to more accurately assess the radial direction faced by electrodes 170 before deploying expandable structure 190 and / or while deploying expandable structure 190. Such assessment can enable a user to rotate delivery catheter 142 and / or expandable structure 190 such that electrodes face in a desired (e.g., targeted direction), such as facing one or more nerves outside of blood vessel 130, before deploying expandable structure 190 to the deployed configuration. Being able to assess the radial direction faced by array of electrodes 170 can also reduce instances in which a user (e.g., a clinician) must re-sheath and / or rotate expandable structure 190 to achieve desired placement of array of electrodes 170 within blood-vessel 130 (e.g., to achieve a desired circumferential alignment of electrodes 170 such that electrodes 170 face in a desired radial direction). Additionally or alternatively, having radiopaque distal extension 198 extend sufficiently distally of expandable structure 190 (e.g., extend sufficiently distally of the main body portion of expandable structure 190) can enable a user to more accurately assess the approximate radial direction faced by electrodes 170 during initial deployment (e.g., expansion) of expandable structure 190, such as when expandable structure is initially advanced distally of distal end 144 of delivery catheter 142. For example, as expandable structure 190 can be configured to rapidly expand to appose a wall of blood vessel 130 when advanced distally of distal end 144 of delivery catheter 142, radiopaque distal extension 198 canextend sufficiently distally of the main body portion of expandable structure 190 (e.g., distally of tubular body distal end 190B) such that a user (e.g., a clinician) can visualize and / or adjust the radial direction faced by array of electrodes 170 in the early stages of deployment of expandable structure 190. Such visualization and adjustment during initial deployment of expandable structure 190 can reduce subsequent instances of re-sheathing and re-deployment of expandable structure 190, such as in cases where the radial direction faced by array of electrodes 170 is less than ideal after an initial deployment of expandable structure 190.

[0140] Radiopaque distal extension 198 can be configured to extend distally from the main body portion of expandable structure 190 (e.g., distally of tubular body distal end 190B) such as to facilitate visualization when expandable structure 190 is the delivery (e.g., compressed) configuration and / or in the early stages of deployment (e.g., expansion) of expandable structure 190. In some examples, radiopaque distal extension 198 extends at least 2 millimeters (mm) distally of tubular body distal end 190B of the tubular body of expandable structure 190. In some examples, radiopaque distal extension 198 extends from about 2.0 mm to about 10.0 mm distally of tubular body distal end 190B of the tubular body of expandable structure 190. In some examples, radiopaque distal extension 198 extends distally of tubular body distal end 190B of the tubular body of expandable structure 190 by at least 4 mm, such as at least about 5 mm or at least 5 mm. Such extension of radiopaque distal extension 198 distally of tubular body distal end 190B can enable a user (e.g., a clinician) to visualize radial direction 133 faced by array of electrodes 170, even when expandable structure 190 is in the delivery configuration (e.g., compressed within delivery catheter 142, such that electrodes 170 are compressed down relatively close to central longitudinal axis 111 of expandable structure 190), and / or even when even when expandable structure 190 is only partially deployed within blood vessel 130 (e.g., where expandable structure 190 is only partially advanced distally of distal end 144 of delivery catheter 142). In some examples, the length of radiopaque distal extension 198 corresponds to an overall length of expandable structure 190, the target vessel into which expandable structure 190 is introduced, and / or the size difference between a delivery instrument (e.g., a delivery catheter) and the target vessel.

[0141] Radiopaque distal extension 198 can define any suitable shape and / or form factor (e.g., which can enable radiopaque distal extension 198 to indicate a radial direction faced by electrodes 170 outwards from expandable structure 190). In some examples, radiopaque distal extension 198 includes a flared portion (e.g., flared outward in the positive and negative y-axis directions according to the orthogonal x-y-z axes in FIG. 3 A). Such a flared portion can define unique shape, such as to differentiate radiopaque distal extension 198 from other radiopaque structures (e.g., such as to differentiate radiopaque distal extension 198 from one or more ofelectrodes 170, which may also be radiopaque). For example, as shown in the example of FIG. 3A and FIG. 3B, radiopaque distal extension 198 includes a circular shaped (e.g., ring shaped and / or donut shaped) flared portion (e.g., shown as the distal-most portion of radiopaque distal extension 198 in the example of FIG. 3 A and FIG. 3B). In some examples, the circular shape of a portion radiopaque distal extension 198 can help to indicate a relative orientation of radiopaque distal extension 198 under a suitable medical imaging modality (e.g., fluoroscopy), which may in turn help indicate the relative radial direction faced by electrodes 170 (e.g., because the circular portion of radiopaque distal extension 198 faces in the same direction as electrodes 170). In some examples, a portion of radiopaque distal extension 198 (e.g., the flared and / or circular portion) includes a relatively flat surface (e.g., relatively flat so as to not extend substantially in the positive and negative z-axis directions according to the orthogonal x-y-z axes in FIG. 3 A). The relatively flat surface of radiopaque distal extension 198 can help additionally or alternatively indicate the relative orientation of radiopaque distal extension 198 under a suitable medical imaging modality (e.g., fluoroscopy), which may in turn help indicate the relative radial direction faced by electrodes 170 (e.g., because the flat surface of radiopaque distal extension 198 faces in the same direction as electrodes 170). In some examples, only the surface of radiopaque distal extension 198 that faces in the same radial direction as electrodes 170 includes a radiopaque material (e.g., only the surface of radiopaque distal extension 198 facing in the positive z-axis direction, or out of the page, in the example of FIG. 3 A). In some examples, radiopaque distal extension 198 includes a linear (e.g., substantially straight) portion that is mechanically coupled to tubular body distal end 190B of expandable structure 190 (e.g., which can serve to connect expandable structure 190 and the flared and / or flat portion of radiopaque distal extension 198).

[0142] Although FIG. 3 A and FIG. 3B is described with respect to electrodes 170 that are configured to deliver electrical stimulation therapy and / or sense electrical signals, endovascular therapy system 100 can additionally or alternatively include other types of therapy delivery elements and / or sensing elements, such as therapy delivery and / or sensing elements for which a directionality for delivery of therapy or sensing of signals may be particularly important. In some examples, endovascular therapy system 100 includes one or more ultrasound transducers or chemical delivery elements (e.g., fluid delivery elements and / or drug elution elements) which can be configured to be attached to expandable structure 190 using a similar method of attachment as electrodes 170. In some examples, endovascular therapy system 100 additionally or alternatively includes one or more temperature sensors, pressure sensors, optical sensors, impedance sensors, chemical sensors, and / or other suitable types of sensing elements, which can be configured to be attached to expandable structure 190 using a similar method of attachment as electrodes 170. Forexample, radiopaque distal extension 198 can be configured to indicate a radial direction faced by the one or more other sensing elements.

[0143] FIG. 4A illustrates an example expandable structure 490, which is an example of expandable structure 19 of FIG. 1 and / or expandable structure 190 of FIG. 3A and FIG. 3B. FIG. 4B illustrates a detailed view of a portion of expandable structure 490, the portion including the portion of expandable structure 490 enclosed by dashed lines labeled as “A” in the example of FIG. 4 A. The examples of FIG. 4 A and FIG. 4B illustrate expandable structure 490 in a two- dimensional view (e.g., as though the tubular body of expandable structure 490 were cut and laid flat in a two-dimensional plane).

[0144] Expandable structure 490 of FIG. 4A and FIG. 4B can be configured similarly to expandable structure 190 of FIG. 3A and FIG. 3B. In some examples, a tubular body portion of expandable structure 490 extends between a tubular body proximal end 490A and a tubular body distal end 490B. In some examples, as shown in the example of FIG. 4A, expandable structure 490 includes a plurality of struts 492 (which may be an example of struts 192 in the example of FIG. 3 A). In some examples, as shown in the example of FIG. 4A, expandable structure 490 includes a plurality of connection elements 464 between (e.g., located axially between) at least some of struts 492. Connection elements 464 may be integrally formed with struts 492 (e.g., include the same material as struts 492), but may be configured to move (e.g., expand, elongated, or the like) different than struts 492, as described herein. Connection elements 464 can be sized, shaped, and otherwise configured to enable expandable structure 490 to be relatively flexible (e.g., able to reversibly deform in different ways without causing irreversible damage to expandable structure 490).

[0145] In the example of FIG. 4A and FIG. 4B, expandable structure 490 also includes a plurality of electrode attachment elements 494 (shown individually as electrode attachment element 494A, electrode attachment element 494B, electrode attachment element 494C, electrode attachment element 494D, electrode attachment element 494E, electrode attachment element 494F, electrode attachment element 494G, and electrode attachment element 494H, collectively referred to herein as electrode attachment elements 494) which may be examples of electrode attachment elements 194 of FIG. 3 A, or any of the other electrode attachment elements described in this disclosure. In the example of FIG. 4A, each of electrode attachment elements 494 is connected to and branches off of one of struts 492. Each of electrode attachment elements 494 can be configured to receive at least one electrode (e.g., such as one or more of electrodes 170 of FIG. 3 A, or any of the other electrodes described in this disclosure), such as to facilitate mechanical coupling of one or more electrodes to expandable structure 490. For example, each ofattachment elements 494 can include a projection configured to be received by (e.g., inserted into) a lumen of one or more electrodes (e.g., as discussed in connection with FIG. 3 A).

[0146] In the example of FIG. 4 A, expandable structure 490 defines a plurality of sections, wherein each section is represented as a column extending in the positive and negative y-axis directions according to the orthogonal x-y-z axes in the example of FIG. 4 A. In other words, each section of expandable structure 490 includes a portion of expandable structure 490 located at a particular axial location and / or spanning an axial distance (e.g., along the x-axis) and extending around a central longitudinal axis 411 of expandable structure 490. In some examples, expandable structure 490 defines central longitudinal axis 411 (e.g., such that central longitudinal axis 411 extends through a radial center of expandable structure 490), and each section extends around longitudinal axis 411 (e.g., in a circumferential direction around longitudinal axis 411). For example, expandable structure 490 defines a plurality of electrode attachment sections 452 (shown individually as electrode attachment section 452A, electrode attachment section 452B, electrode attachment section 452C, and electrode attachment section 452D, but collectively referred to herein as electrode attachment sections 452). Each of electrode attachment sections 452 can include one or more electrode attachment elements 494 (e.g., each of which may be configured to receive one or more electrodes). In the example of FIG. 4A, each of electrode attachment section 452A, electrode attachment section 452B, electrode attachment section 452C, and electrode attachment section 452D includes at least two electrode attachment elements 494 (e.g., electrode attachment section 452 A includes electrode attachment element 494 A and electrode attachment element 494B, electrode attachment section 452B includes electrode attachment element 494C and electrode attachment element 494D, electrode attachment section 452C includes electrode attachment element 494E and electrode attachment element 494F, and electrode attachment section 452D includes electrode attachment element 494G and electrode attachment element 494H). However, each of electrode attachment sections 452 can include any suitable number of electrode attachment elements 494 (e.g., one, two, three, four, five, six, ten, or more, or any suitable number therebetween). Further, while the example of FIG. 4A shows expandable structure 490 with four of electrode attachment sections 452, expandable structure 490, or any of the other expandable structures described in this disclosure, can have any suitable number of electrode attachment sections 452 (e.g., one, two, three, four, five, six, seven, eight, nine, ten, or more electrode attachment sections 452).

[0147] In some examples, each of electrode attachment elements 494 is mechanically coupled to at least one electrode, such that a number of electrodes attached to expandable structure 490 correspond to the number of electrode attachment elements. However, in other examples, less than all of electrode attachment elements 494 are mechanically coupled to anelectrode. This may enable different patterns and / or configurations of electrodes that are eventually attached to expandable structure 490, as may be desired for different therapeutic applications and / or different vascular locations and / or different patient anatomies, such that expandable structure 490 may function as a customizable template for different spatial arrangements of electrodes and / or other therapy delivery elements and / or sensing elements. Further, expandable structure 490 can accommodate more or less electrodes depending on the type and / or configuration of medical device that the electrodes are electrically coupled to (e.g., wherein a medical device, such as medical device 14 of FIG. 1 and FIG. 2 can have any suitable number of channels for electrically connecting to one or more electrodes, such as four channels, eight channels, sixteen channels, or another suitable number of channels).

[0148] In some examples, when electrodes are attached to expandable structure 490 via electrode attachment elements 494, electrodes of a given one of electrode attachment sections 452 are disposed at a common axial location along expandable structure (e.g., a common axial location along the x-axis direction according to the orthogonal x-y-x axes in FIG. 4A). In some examples, when electrodes are attached to expandable structure 490 via electrode attachment elements 494, electrodes of different electrode attachment sections 452 are disposed at common or different circumferential positions around expandable structure 490. For example, as shown in FIG. 4A, electrode attachment element 494A, electrode attachment element 494C, electrode attachment element 494E, and electrode attachment element 494G can be considered to be disposed at a first common circumferential position around expandable structure 490 (e.g., such that when electrodes are attached to each of electrode attachment element 494A, electrode attachment element 494C, electrode attachment element 494E, and electrode attachment element 494G, the electrodes are substantially aligned along the x-axis direction). Similarly, electrode attachment element 494B, electrode attachment element 494D, electrode attachment element 494F, and electrode attachment element 494H can be considered to be disposed at a second common circumferential position around expandable structure 490 (e.g., such that when electrodes are attached to each of electrode attachment element 494B, electrode attachment element 494D, electrode attachment element 494F, and electrode attachment element 494H, the electrodes are substantially aligned along the x-axis direction). In this way, expandable structure 490 can be configured to have multiple different groups of axially and / or circumferentially spaced apart electrodes (e.g., electrode groups as discussed in relation to FIG. 3 A and FIG. 3B).

[0149] In some examples, expandable structure 490 defines one or more additional sections (e.g., other than electrode attachment sections 452). In some examples, expandable structure 490 defines a proximal-most section 456 (e.g., which is located proximal to all electrode attachment sections 452). In some examples, when expandable structure 490 is in a deployed (e.g., expandedconfiguration), proximal-most section 456 is configured to have a larger outer maximum dimension (e.g., diameter, in the case of a circular cross section) as compared to at least some of electrode attachment sections 452. In some examples, as described in connection with FIG. 5A and FIG. 5B, this larger outer maximum dimension (e.g., diameter) can help anchor expandable structure 490 within a blood vessel of a patient (e.g., blood vessel 130, as shown in the example of FIG. 3B). In some examples, as shown in the example of FIG. 4A, proximal-most section 456 includes a subset of struts 492 having crowns directly connected (e.g., without any intervening connection elements 464).

[0150] In some examples, expandable structure 490 defines at least one intermediate section 458. In some examples, intermediate section 458 does not include any electrode attachment elements 494 and is positioned between proximal-most section 456 and a proximal-most one of electrode attachment sections 452 (e.g., electrode attachment section 452D in the example of FIG. 4A). In some examples, expandable structure 490 includes more than one or intermediate section 458 (e.g., that are interspersed between two or more of electrode attachment sections 452). In some examples, as shown in the example of FIG. 4A, each of proximal-most section 456 and intermediate section 458 do not include any electrode attachment elements.

[0151] In some examples, as shown in the example of FIG. 4 A, each of electrode attachment sections 452, proximal-most section 456, and intermediate section 458 includes a subset of struts 492 that define (e.g., form) a respective plurality of proximal crowns 493 and a plurality of distal crowns 495 (only a subset of proximal crowns 493 and plurality of distal crowns 495 labeled in FIG. 4A). Each of proximal crowns 493 and distal crowns 495 of each of electrode attachment sections 452, proximal-most section 456, and intermediate section 458 can include a vertex where two or more of struts 492 intersect to form a respective proximal apex (e.g., otherwise referred to herein as a proximal crown 493) or distal apex (e.g., otherwise referred to herein as a distal crown 495). As shown in the example of FIG. 4A, each of electrode attachment sections 452, proximal-most section 456, and intermediate section 458 includes ten distal crowns 495 and ten proximal crowns 495. However, in other examples, each of electrode attachment sections 452, proximal-most section 456, and / or intermediate section 458 has more or less than ten distal crowns 495 and / or ten proximal crowns 495. In some examples, the number and spacing of crowns corresponds to the spacing of electrode attachment elements 494 when expandable structure 490 is in the deployed (e.g., expanded) configuration, and each of each of electrode attachment sections 452, proximal-most section 456, and / or intermediate section 458 has a suitable number of crowns to facilitate desired axial and / or circumferential spacing between electrode attachment elements 494. In some examples, each of electrode attachment sections 452, proximal-most section 456, and intermediate section 458 include a suitable number of crowns,such as 8 proximal crowns 493 to 16 proximal crowns 493 and 8 distal crowns 495 to 16 distal crowns 495. As shown in the example of FIG. 4A, each of electrode attachment sections 452, proximal-most section 456, and intermediate section 458 include the same number of proximal crowns 493 and distal crowns 495.

[0152] As shown in the example of FIG. 4 A, expandable structure 490 defines a plurality of connection sections 462 (e.g., shown individually as connection section 462 A, connection section 462B, connection section 462C, connection section 462D, and connection section 462E, collectively referred to herein as connection sections 462). In some examples, each of connection sections 462 are axially interspersed between at least two of electrode attachment sections 452, intermediate section 458, and / or proximal-most section 456 such that connection elements 464 of each of connection sections 462 are configured to mechanically couple axially adjacent ones of electrode attachment sections 452, intermediate section 458, and / or proximal-most section 456. As shown in the example of FIG. 4 A, connection sections 462 do not have any electrodes attached to any of connection sections 462.

[0153] In some examples, for at least some directly adjacent electrode attachment sections 452 (e.g., including at least a pair of electrode attachment sections 452 including at least a proximal one of electrode attachment sections 452 and a distal one of electrode attachment sections 452), at least a subset of respective distal crowns 495 of the proximal one of electrode attachment sections 452 are coupled to at least a subset of the respective proximal crowns 493 of the distal one of electrode attachment sections 452 (e.g., via respective ones of connection sections 462 between the two electrode attachment sections 452). In some examples, for at least some pairs of two adjacent electrode attachment sections 452, all of respective distal crowns 495 of the proximal one of electrode attachment sections 452 are mechanically coupled to respective proximal crowns 493 of the distal one of electrode attachment sections 452. As shown in the example of FIG. 4A, for adjacent ones of electrode attachment sections 452, all respective distal crowns 495 of one of electrode attachment sections 452 are connected to corresponding proximal crowns 493 of another one of electrode attachment sections 452. Said another way, for all pairs of electrode attachment sections 452 including at least a proximal one of electrode attachment sections 452 and a distal one of electrode attachment sections 452, all distal crowns 495 of the proximal one of electrode attachment sections 452 are mechanically coupled to the corresponding proximal crowns 493 of the distal one of electrode attachment sections 452, such that all distal crowns 495 and all corresponding proximal crowns 493 are mechanically connected for adjacent pairs of electrode attachment sections 452 (e.g., except for the distal-most electrode attachment section 452A, for which distal crowns 495 are not connected to other corresponding crowns). Similarly, all proximal crowns 493 (e.g., except for those proximal crowns 493 of proximal -mostsection 456) are mechanically connected to corresponding distal crowns 495 of adjacent ones of electrode attachment sections 452.

[0154] Having all distal crowns 495 and proximal crowns 493 connected to each other (e.g., at least for all corresponding adjacent ones of electrode attachment sections 452) can facilitate and / or enable expandable structure to be more easily re-sheathed (e.g., re-sheathed into a delivery catheter, such as subsequent to having been advanced to distally of the delivery catheter). For example, by having at least some of proximal crowns 493 not connected to adjacent distal crowns 495, the unconnected proximal crowns 493 may catch and / or snag on a distal end of a delivery catheter (e.g., distal end 144 of delivery catheter 142 of FIG. 3B), such as to prevent expandable structure 490 from being able to be re-sheathed in the delivery catheter. By being configured to be re-sheathed, expandable structure 490 can be repeatedly transformed between the relatively low-profile delivery (e.g., compressed) configuration and the deployed (e.g., expanded) configuration (e.g., by advancing distally advancing relative to and / or being retracted proximally relative to a delivery catheter distal end). Such ability to be repeatedly transformed between the relatively low-profile delivery (e.g., compressed) configuration and the deployed (e.g., expanded) configuration can enable a user (e.g., a clinician) to try multiple deployments of expandable structure 490 within vasculature of a patient, such as to achieve improved therapeutic effectiveness of therapy and / sensing via electrodes on expandable structure 490 by better placement of expandable structure 490 within the vasculature.

[0155] In other examples, as described later in this disclosure, less than all of respective distal crowns 495 of the proximal electrode one of electrode attachment sections 452 are coupled to respective ones of proximal crowns 493 of the distal one of electrode attachment sections 452.

[0156] In some examples, each of connection sections 462 includes one or more connection elements 464 configured to mechanically connect adjacent ones of electrode attachment sections 452, intermediate section 458, and / or proximal-most section 456. For example, in some examples, each of connection elements 464 are configured to connect distal crowns 495 and proximal crowns 493 of adjacent ones of electrode attachment sections 452. As shown in the example of FIG. 4 A, each of connection elements 464 extends between and mechanically connects at least two electrode attachment sections 452 by connecting respective proximal crowns 495 to adjacent proximal crowns 493 of adjacent electrode attachment sections 452.

[0157] In some examples, one or more of connection elements 464 are configured to deform (e.g., reversibly deform) to accommodate axial extension and / or circumferential expansion of expandable structure 490. In some examples, one or more of connection elements 464 are configured to straighten (e.g., axially elongate and become straight, such as in the x-axis direction according to the orthogonal x-y-z axes in FIG. 4A and FIG. 4B) in response to an axialforce applied to expandable structure 490 (e.g., in the x-axis direction). For example, expandable structure 490 may be deployed in a portion of vasculature that includes a bend or other structure that creates extension (e.g., straightening of connection element 464) or compression (e.g., bending of connection element 464). In some examples, one or more of connection elements 464 defines one or more curved portions that are configured to straighten in response to an axial force applied to expandable structure 490. In some examples, one or more of connection elements 464 defines multiple curved portions, where each of the multiple curved portions are configured to straighten in response to an axial force applied to expandable structure 490. In some examples, one or more of connection elements 464 defines a s-shape (e.g., a shape with two curved portions that extend in opposite directions, such as to form a trough and a peak). In some examples, the ability of one or more of connection elements 464 to reversibly deform (e.g., straighten) enhances the flexibility of expandable structure 490.

[0158] FIG. 4B illustrates a detail view of a portion of expandable structure 490 of FIG. 4 A, the detail view including the portion expandable structure 490 enclosed by dashed lines labeled as “A” in the example of FIG. 4 A. In particular, FIG. 4B illustrates axially adjacent electrode attachment sections 452B and 452C, which are separated by and connected via connection section 462B. Electrode attachment section 452C includes electrode attachment element 494E branching off of strut 492A and electrode attachment element 494F branching off of strut 492B, where each of strut 492 A and strut 492B are one of struts 492 of the example of FIG. 4 A. Strut 492A extends distally to form distal crown 495A and strut 492B extends distally to form distal crown 495B, where each of distal crown 495A and distal crown 495B are examples of distal crowns 495 discussed in connection with FIG. 4A. Strut 492C extends proximally to form proximal crown 493 A and strut 492D extends proximally to form proximal crown 493B, where each of proximal crown 493 A and proximal crown 493B are examples of proximal crowns 493 discussed in connection with FIG. 4A.

[0159] In the example of FIG. 4B, each of a connection element 464A and a connection element 464B are configured to mechanically connect portions of electrode attachment section 452C to respective portions of electrode attachment section 452B. In particular, connection element 464A mechanically connects distal crown 495A of electrode attachment section 452C to proximal crown 493 A of electrode attachment section 452B and connection element 464B mechanically connects distal crown 495B of electrode attachment section 452C to proximal crown 493B of electrode attachment section 452B. Each of connection element 464 A and connection element 464B can be examples of connection elements 464 discussed in connection with FIG. 4A.

[0160] As shown in FIG. 4B, connection element 464A is rotationally symmetric and / or reflectionally symmetric about an axial midpoint 467 of connection element 464A. Axial midpoint 467 is a midpoint of connection element 464A in a longitudinal direction (e.g., along a longitudinal axis 413, which is shown as extending in the x-axis direction according to the orthogonal x-y-z axes in the example of FIG. 4B). For example, the portion of connection element 464A between distal crown 495A and midpoint 467 can be rotated around midpoint 467 to define the portion of connection element 464A between midpoint 467 and proximal crown 493 A, and is thus rotationally symmetric about midpoint 467. Additionally or alternatively, the portion of connection element 464A between distal crown 495 A and midpoint 467 can be reflected across midpoint 467 (e.g., in a plane formed by the x-axis and y-axis according to the orthogonal x-y-x axes in FIG. 4B) to define the portion of connection element 464A between midpoint 467 and proximal crown 493 A, and is thus reflectionally symmetric about axial midpoint 467. With reference to FIG. 4A, where each of connection elements 464 is rotationally symmetric and / or reflectionally symmetric about an axial midpoint of the respective axial midpoint 467, expandable structure 490 may expand in such a way that facilitates uniform expansion and / or extension of expandable structure 490. For example, when a force (e.g., a tension force) is applied to expandable structure 490 (e.g., in a longitudinal and / or axial direction along expandable structure 490), each of connection elements 464 being rotationally and / or reflectionally symmetric about respective axial midpoints 467 of each of connection elements 464 can limit or prevent rotation of electrode attachment sections 452 relative to each other (e.g., when expandable structure 490 is axially extended and / or radially expanded). For example, rotationally and / or reflectionally symmetry of connection elements 464 can prevent movement of electrode attachment section 452C relative to electrode attachment section 452B in the y-axis direction. By limiting or preventing such relative movement (e.g., rotation) between electrode attachment sections 452, a clinician may be able to more easily align electrodes attached to electrode attachment elements 494 with target tissue, even when expandable structure 490 is under a force (e.g., a tension force) that would otherwise cause electrodes attached to expandable structure 490 to move (e.g., rotate) relative to each other.

[0161] In other examples, as discussed in relation to other examples of this disclosure, one or more of connection elements 464 define other shapes and / or form factors (e.g., form factors that are reflectionally symmetric about a circumferential plane, such as a circumferential plane 415 of FIG. 4B). In some examples, one or more of connection elements 464 are substantially straight (e.g., such that one or more of connection elements 464 generally extend axially along expandable structure 490 in the x-axis direction without substantially deviating in the y-axis direction).

[0162] In some examples, as shown in the example of FIG. 4 A and FIG. 4B, all connection elements 464 of a given one of connection sections 462 defines the same shape and / or same form factor. By defining the same shape and / or form factor, connection elements 464 can enable and / or facilitate uniform expansion and / or extension of expandable structure 490. For example, when a tension force is applied to expandable structure 490 in a longitudinal (e.g., axial) direction along expandable structure 490, connection elements 464 being the same shape can limit or prevent rotation of electrode attachment sections 452 relative to each other. By limiting or preventing such relative movement (e.g., rotation) between electrode attachment sections 452, a clinician may be able to more easily align electrodes attached to electrode attachment elements 494 with target tissue.

[0163] In some examples, connection elements 464 are sized, shaped, and / or otherwise configured to limit interference (e.g., physical interference) with electrode attachment elements 494. For example, as shown in the example of FIG. 4B, connection element 464A, which may be an example of any or all of connection elements 464 of expandable structure 490 of FIG. 4 A, defines a shape and / or form factor that enables and / or allows for one or more electrodes to be affixed to and / or disposed on electrode attachment elements 494E, which is positioned proximal to connection element 464 A. In some examples, as shown in the example of FIG. 4B, connection element 464A defines an s-shape such that a trough 465 of the s-shape is positioned next to and extends away from electrode attachment element 494E (e.g., such as to reduce or eliminate potential physical interference with one or more electrodes that is mechanically coupled to electrode attachment element 494E). In some examples, a proximal portion of connection element 464 A defines trough 465. The s-shape of connection element 464 A including trough 465 as shown in FIG. 4B can enable connection element 464A to maintain rotational and / or reflectional symmetry about axial midpoint 467 while also avoiding physical interference with one or more electrodes mechanically coupled to electrode attachment element 494E.

[0164] In some examples, connection element 464A, which is positioned directly adjacent and distal to electrode attachment element 494E, defines longitudinal axis 413. As shown in the example of FIG. 4B, longitudinal axis 413 extends at least between a proximal and a distal end of the connection element 464A and intersects axial midpoint 467 of connection element 464A. In the example of FIG. 4B, longitudinal axis 413 extends in the longitudinal direction of expandable structure 490 (e.g., in the positive and negative x-axis direction according to the orthogonal x-y-z axes of FIG. 4B). In some examples, trough 465 is on a first side of longitudinal axis 413 (e.g., a side of longitudinal axis in the negative y-axis direction). In the example of FIG. 4B, electrode attachment element 494E is positioned on a second side of longitudinal axis 413 (e.g., a side of longitudinal axis in the positive y-axis direction) opposite the first side. In this way, connectionelement 464A defines an s-shape such that trough 465 of the s-shape is positioned relative to electrode attachment element 494E such as to limit or prevent connection element 464A from physically interfering with a respective electrode mechanically coupled to electrode attachment element 494E.

[0165] Struts 492 can be sized, shape, oriented, and / or otherwise configured to facilitate the ability of expandable structure 490 to be crimped down (e.g., into a compressed, delivery configuration) and subsequently transformed to a deployed (e.g., expanded) configuration, such as to maintain suitable electrode spacing when expandable structure 490 is the in the deployed configuration. For example, adjacent and connecting struts 492 of a given section (e.g., each of electrode attachment sections 452) can be configured to maintain a relative angle of less than about 90 degrees, such as less than about 80 degrees when expandable structure 490 is in the deployed (e.g., expanded configuration). As an illustrative example, in example of FIG. 4B, strut 492A and an adjacent strut 492E (e.g., that together form distal crown 495A) are disposed at an angle Rl. When transformed to the fully deployed (e.g., expanded) configuration, such that expandable structure 490 is fully apposed to a vessel wall, angle Rl is less than about 90 degrees, such as less than 80 degrees and / or less than 80 degrees, but greater than about 50 degrees. In some examples, when transformed to the fully deployed (e.g., expanded) configuration, such that expandable structure 490 is fully apposed to a vessel wall, angle Rl is 50 degrees to 90 degrees, or any suitable subrange thereof. By keeping angle Rl less than or equal to 90 degrees, such as when expandable structure 490 is in a fully deployed configuration, each of struts 492 (e.g., including strut 492A and strut 492E of FIG. 4B) remain “in plane” (e.g., in the plane of the cylindrical surface formed by the tubular body of expandable structure 490 when expandable structure 490 is in the radially expanded configuration). Keeping each of struts 492 in plane (e.g., in the plane if the cylindrical surface formed by the tubular body of expandable structure 490 when expandable structure 490 is in the radially expanded configuration), can facilitate relatively uniform and consistent spacing between electrodes (e.g., electrodes attached to electrode attachment elements 494) as well as ensure that electrodes attached to expandable structure 490 are fully apposed to a blood vessel wall.

[0166] In the example of FIG. 4A, expandable structure 490 includes a radiopaque distal extension 498, which may be an example of radiopaque distal extension 198 of FIG. 3 A and FIG. 3B, or any of the other radiopaque distal extension described in this disclosure. In some examples, radiopaque distal extension 498 is mechanically coupled to and extends from one of struts 492 of a distal-most electrode attachment section 452A. In some examples, radiopaque distal extension 498 is mechanically coupled to one of distal crowns 495 of electrode attachment section 452A. In some examples, at least a portion of radiopaque distal extension 498 includes aradiopaque or radiographic material that is visible via a suitable medical imaging modality (e.g., fluoroscopy). In some examples, a distal-most portion of radiopaque distal extension 498 includes the radiopaque or radiographic material.

[0167] In some examples, as shown in the example of FIG. 4A, radiopaque distal extension 498 is generally circumferentially aligned with one or more of electrode attachment elements 494A-494H around expandable structure 490 (e.g., such that radiopaque distal extension 498 is positioned circumferentially around expandable structure 490 at a similar circumferential location as one or more of electrode attachment elements 494A-494H). In some examples, when one or more electrodes are attached to expandable structure 490 via one or more of electrode attachment elements 494A-494H, radiopaque distal extension 498 is generally circumferentially aligned with the electrodes. For example, in some examples, radiopaque distal extension 498 is circumferentially aligned with a circumferential center of an array formed by multiple electrodes attached to expandable structure 490, as measured around the circumference of expandable structure 490 (e.g., in the positive and negative y-axis direction according to the orthogonal x-y-z axes in FIG. 4A).

[0168] In some examples, radiopaque distal extension 498 extends distally of distal end 490B of expandable structure 490 by a distance LI. In some examples, LI is at least 2 millimeters (mm). In some examples, LI is 2.0 mm to about 10.0 mm. In some examples, LI is least 4 mm, such as at least about 5 mm or at least 5 mm. As discussed in connection with FIG. 3 A and FIG. 3B, such values of LI can enable a user (e.g., a clinician) to visualize a radial direction faced by an array of electrodes attached to expandable structure 490 via one or more of electrode attachment elements 494, even when expandable structure 490 is in the delivery configuration.

[0169] In some examples, expandable structure 490 includes a plurality of radiopaque proximal extensions 499 (shown individually as radiopaque proximal extension 499A, radiopaque proximal extension 499B, and radiopaque proximal extension 499C, but collectively referred to herein as radiopaque proximal extensions 499). In some examples, radiopaque proximal extensions 499 include a radiographic and / or radiopaque material, which can facilitate viewing of expandable structure 490 under a suitable medical imaging modality (e.g., radiography, fluoroscopy, or the like). In some examples, each of radiopaque proximal extensions 499 extends proximally of tubular body proximal end 490A of the tubular body portion of expandable structure 490. As shown in the example of FIG. 4A, radiopaque proximal extensions 499 are mechanically coupled to and extend from proximal crowns 493 of proximal- most section 456 of expandable structure 490.

[0170] While the example of FIG. 4 A includes three radiopaque proximal extension 499, any suitable number of radiopaque proximal extension 499 can be used (e.g., one, two, three, four,five, six, seven, eight, nine, ten, or more). In some examples, expandable structure 490 includes at least one of radiopaque proximal extension 499. In some examples, as radiopaque proximal extension 499 can be coupled to and extend from proximal crowns 493 of proximal-most section 456, the number of radiopaque proximal extensions 499 is equal to or less than the number of proximal crowns 493 of proximal-most section 456. In some examples, each proximal crown 493 of proximal-most section 456 of expandable structure 490 is mechanically coupled to and / or forms one of radiopaque proximal extensions 499. In some examples, where the number of radiopaque proximal extensions 499 is less than the number of proximal crowns 493 of proximal- most section 456, circumferentially adjacent radiopaque proximal extensions 499 are spaced apart by at least two of proximal crowns 493. Using multiple, circumferentially spaced apart radiopaque proximal extensions 499 can enable a clinician to both determine the location of the tubular body proximal end 490A of expandable structure 490, as well as determine a degree (e.g., relative amount) of radial expansion of expandable structure 490.

[0171] In some examples, at least some of radiopaque proximal extensions 499 are mechanically coupled to a medical lead and / or another elongated body (e.g., such that at least some of radiopaque proximal extensions 499 facilitate mechanical coupling between of expandable structure 490 and a medical lead and / or another elongated body). For example, at least some of radiopaque proximal extensions 499 can be welded, crimped, or otherwise mechanically coupled to a portion of a medical lead (e.g., medical lead 160 of FIG. 3A) and / or other elongated body.

[0172] In some examples, as shown in the example of FIG. 4 A, each of radiopaque proximal extensions 499 are positioned circumferentially offset from all of electrode attachment elements 494 (e.g., around expandable structure 490, where the circumference around expandable structure 490 is the y-axis direction according to the orthogonal x-y-z axes of FIG. 4A). In other words, each of radiopaque proximal extensions 499 are offset from all of electrode attachment elements 494 along the y-axis such that none of radiopaque proximal extensions 499 are axially aligned with any of electrode attachment elements 494 along an axis parallel to the x-axis direction. When one or more electrodes are affixed to each of electrode attachment elements 494 to form an array of electrodes, each of radiopaque proximal extensions 499 are positioned circumferentially offset from the array of electrodes. By having radiopaque proximal extensions 499 circumferentially offset from electrodes attached to electrode attachment elements 494 (e.g., in a direction around expandable structure 490) a user (e.g., a clinician) can more easily visualize a position of one or more of the electrodes. For example, in certain viewing angles under a suitable medical imaging modality, having radiopaque proximal extensions 499 circumferentially aligned with one or more electrodes can impede visualization of electrodes (e.g., which may also beradiographic and / or radiopaque) attached to electrode attachment elements 494. Thus, by having radiopaque proximal extensions 499 circumferentially offset from electrodes attached to electrode attachment elements 494, radiopaque proximal extensions 499 may be less likely to impede visualization of electrodes attached to electrode attachment elements 494. Further, by having radiopaque proximal extensions 499 circumferentially offset from electrodes attached to electrode attachment elements 494, forces that may otherwise cause the electrodes to be less apposed to the vessel wall (e.g., radial forces exerted by radiopaque proximal extensions 499 against a vessel wall) are reduced or eliminated.

[0173] In other examples, at least one of radiopaque proximal extensions 499 is circumferentially aligned with one or more of electrode attachment elements 494 and / or circumferentially aligned with an array of electrodes attached to electrode attachment elements 494, such as to indicate a radial direction faced by the array of electrodes attached to electrode attachment elements 494 (as discussed in relation to radiopaque distal extension 498).

[0174] FIG. 5A illustrates an example expandable structure 590, which is an example of expandable structure 19 of FIG. 1, expandable structure 190 of FIG. 3 A and FIG. 3B, expandable structure 490 of FIG. 4A and FIG. 4B, and / or any of the other expandable structures described in this disclosure. For example, expandable structure 590 includes a plurality of struts 592 and a plurality of electrode attachment elements 594, which may be examples of struts 192 and electrode attachment elements 194 of FIG. 3 A, respectively. In the example of FIG. 5 A, expandable structure 590 extends from an expandable structure proximal end 590A to an expandable structure distal end 590B and defines a central longitudinal axis 511 (e.g., such that central longitudinal axis 511 extends through a radial center of expandable structure 590). In the example of FIG. 5 A, each of electrode attachment elements 594 branch of at least one of struts 592.

[0175] In some examples, as shown in the example of FIG. 5 A, expandable structure includes a proximal portion 501 and a distal portion 502, wherein distal portion 502 includes electrode attachment elements 594. When one or more electrodes are mechanically coupled to expandable structure 590, distal portion 502 of expandable structure 590 includes an array of electrodes. As shown in the example of FIG. 5 A, proximal portion 501 does not include any electrode attachment elements 594 (and thus does not include any electrodes). In some examples, proximal portion 501 includes proximal end 590A of expandable structure 590. In some examples, a length of proximal portion 501 (e.g., as measured along central longitudinal axis 511) is about 10 percent to about 30 percent of the overall length of expandable structure 590, such as about 20 percent of the overall length of expandable structure 590. In some examples, distal portion 502 includes distal end 590B of expandable structure 590.

[0176] In the example of FIG. 5 A, expandable structure 590 is in a deployed (e.g., expanded) configuration, and at least a portion of expandable structure 590 is configured to anchor expandable structure 590 with a blood vessel of a patient (e.g., blood vessel 130 of FIG. 3B). For example, at least proximal portion 501 of expandable structure 590 (e.g., which can include proximal end 590A of expandable structure 590) is configured to anchor expandable structure 590 within a blood vessel of a patient (e.g., by exerting a sufficient radial force on an inner wall of a blood vessel to limit or prevent axial movement and / or rotation of expandable structure 590 relative to the blood vessel). In some examples, distal portion 502, which can include one or more electrodes mechanically coupled to each of electrode attachment elements 594, is configured to position the electrodes against a blood vessel wall for therapeutically effective therapy delivery and / or sensing from an endovascular location. However, in some examples, distal portion 502 does not exert a sufficient radial force to limit or prevent movement of expandable structure 590 relative to the blood vessel. In other words, proximal portion 501 can be configured to provide a first radial force outward from longitudinal axis 511 to anchor expandable structure 590 within a blood vessel, while distal portion 502 is configured to provide a second radial force outward from longitudinal axis 511 sufficient to bring electrodes attached to electrode attachment elements 594 into apposition with a blood vessel wall. In some examples, the first radial force exerted by proximal portion 501 is greater than the second radial force exerted by the distal portion 502 of expandable structure 590.

[0177] In some examples, as shown in the example of FIG. 5 A, when expandable structure 590 is in the deployed (e.g., expanded) configuration, proximal portion 501 defines a maximum outer dimension that is greater than another portion (e.g., a distal portion 502) of expandable structure 590, such that proximal portion 501 helps anchor expandable structure 590 with a blood vessel of a patient (e.g., such as in cases of high blood flow across expandable structure 590 when expandable structure 590 is implanted in vasculature of a patient). For example, when expandable structure 590 is in the deployed configuration (e.g., within a blood vessel such as jugular vein 13), proximal portion 501 of expandable structure 590 defines a first maximum dimension DI and a distal portion 502 of expandable structure defines a second maximum dimension D2, wherein first maximum dimension DI is greater than second maximum dimension D2. In examples where either of proximal portion 501 or distal portion 502 of expandable structure 590 define circular or nearly circular cross-sections, first maximum dimension DI and / or second maximum dimension D2 can be diameters.

[0178] By having proximal portion 501 provide the majority of the anchoring force needed to anchor expandable structure 590 within a blood vessel, a clinician can more easily rotate expandable structure 590 (e.g., about longitudinal axis 511) within a blood vessel whenexpandable structure 590 is only partially deployed from a delivery catheter (e.g., delivery catheter 142 in the example of FIG. 3B). For example, where only distal portion 502 (or a subportion thereof) of expandable structure 590 is advanced distally of a delivery catheter and permitted to expand (e.g., such that proximal portion 501 is still within the delivery catheter, and not expanded against a blood vessel wall), a clinician can rotate expandable structure 590 (e.g., about longitudinal axis 511) to orient an array of electrode mechanically coupled to expandable structure 590 such that the array of electrodes faces a target radial direction (e.g., a target radial direction outwards from longitudinal axis 511).

[0179] In some examples, second maximum dimension D2 corresponds to a nominal size of expandable structure 590 (e.g., which can include a stent). In some examples, second maximum dimension D2 (e.g., which can be a diameter in the case of a circular cross-cross section of expandable structure 590) is 10 millimeters (mm) to 24 mm. In some examples, first maximum dimension DI is slightly larger than second maximum dimension D2 (e.g., slightly larger than the nominal size of expandable structure 590), such as to help anchor expandable structure within vasculature of a patient. In some examples, first maximum dimension DI is larger than second maximum dimension D2 by about 1.0 mm to about 6.0 mm (or any value therebetween), such as about 2.0 mm to about 5.0 mm, or such as about 3.0 mm. In some examples, the difference between first maximum dimension DI and second maximum dimension D2 enables proximal portion 501 to anchor expandable structure 590 within vasculature of a patient. In some examples, DI is larger than second maximum dimension D2 by at least 1.0 mm, such as about 2.0 mm.

[0180] In some examples, as illustrated in the example of FIG. 5 A, proximal portion 501 defines a uniform or nearly uniform outer maximum dimension (e.g., first maximum dimension DI). For example, proximal portion 501 can define a uniform or nearly uniform outer maximum dimension (e.g., first maximum dimension DI, which can be a diameter) from a distal end of proximal portion 501 to a proximal end of proximal portion 501 (e.g., wherein the proximal end of proximal portion 501 is also expandable structure proximal end 590A). Such a uniform maximum outer dimension along the length of proximal portion 501 can ensure a sufficient portion of expandable structure 590 contacts a vessel wall to anchor expandable structure 590 with vasculature of a patient. In other examples, as discussed in connection with FIG. 5B, proximal portion 501 does not define a uniform outer dimension.

[0181] FIG. 5B illustrates another variation of example expandable structure 590, which is an example of expandable structure 19 of FIG. 1, expandable structure 190 of FIG. 3 A and FIG. 3B, expandable structure 490 of FIG. 4A and FIG. 4B, and / or any of the other expandable structures described in this disclosure. Expandable structure 590 of FIG. 5B may be configured likeexpandable structure 590 of FIG. 5 A, except as described herein. For example, in some examples, proximal portion 501 of expandable structure 590 does not define a uniform outer maximum dimension (e.g., first maximum dimension DI, which can be a diameter), as shown in the example of FIG. 5B. In some examples, proximal portion 501 defines a taper. For example, in some examples, proximal portion 501 tapers from first maximum dimension DI (e.g., at expandable structure proximal end 590A) to second maximum dimension D2 (e.g., at a location between expandable structure proximal end 590A and expandable structure distal end 590B). In some examples, as shown in the example of FIG. 5B, the proximal portion 501 that includes a taper is proximal to at least some (e.g., all) electrode attachment elements 594. In examples in which proximal portion 501 includes a taper, the taper of proximal portion 501 can enable expandable structure 590 to accommodate a range of blood vessel types and / or blood vessel sizes (e.g., diameters), and be anchored within such blood vessels.

[0182] In some examples, as shown in the example of FIG. 5B, proximal portion 501 defines a uniform taper (e.g., a uniform taper angle over an axial length of proximal portion 501). In some examples, proximal portion 501 defines a frustoconical shape. In other examples, proximal portion 501 does not define a uniform taper. In some examples, proximal portion 501 defines a non-uniform taper (e.g., proximal portion 501 defines a non-unform taper angle over at least a portion of an axial length of proximal portion 501).

[0183] FIG. 6A illustrates an example electrode attachment element 694, which is an example of any of electrode attachment elements 194 of FIG. 3 A and FIG. 3B, and / or any of the other electrode attachment elements described in this disclosure. FIG. 6B illustrates a distal portion of electrode attachment 694 of FIG. 6A. In the example of FIG. 6A, an electrode 670 (which may be an example of any of electrodes 170 of FIG. 3 A and 3B, or any of the other electrodes or other therapy delivery elements of this disclosure) is positioned on electrode attachment element 694.

[0184] As shown in the example of FIG. 6 A, electrode attachment element 694 includes a projection 696 that is mechanically coupled to and branches off of a strut 692. In some examples, projection 696 is integrally formed with strut 692 (e.g., wherein projection and strut 692 are formed from a common piece of laser-cut material). Projection 696 and strut 692 may be examples of projection 196 and one of struts 192 of FIG. 3 A, respectively. As shown in the example of FIG. 6A, projection 696 branches off of strut 692 and extends substantially parallel to a portion of strut 692 (e.g., such that projection 696 generally forms a “L” shape). Strut 692 may be a portion of an overall expandable structure (e.g., expandable structure 190 of FIG. 3A).

[0185] In some examples, electrode attachment element 694 is sized, shaped, and / or otherwise configured to limit or prevent contact between electrode 670 and strut 692. Forexample, in some examples, electrode attachment element 694 is sized, shaped, and / or otherwise configured to limit or prevent contact between electrode 670 and strut 692 such as when an external force causes projection 696 to bend or flex toward strut 692. Limiting and / or preventing contact between electrode 670 and strut 692 can prevent electrical shorting between electrode 670 and strut 692 (e.g., such that electrode 670 and strut 692 remain electrically isolated). As electrical communication between electrode 670 and strut 692 can lead to less energy delivered via electrode 670 to target tissue of a patient, limiting or preventing contact between electrode 670 and strut 692 can ensure that a relatively small amount electrical energy delivered via electrode 670 is lost due to contact with strut 692.

[0186] In the example of FIG. 6A, a portion of projection 696 that is not surrounded by electrode 670 is configured to contact strut 692 before electrode 670 contacts strut 692 (e.g., when an external force is applied to projection 696 of electrode attachment element 694 that causes projection 696 to bend and / or flex toward strut 692). In this way, projection 696 is sized, shaped, and otherwise configured to maintain physical separation between electrode 670 and strut 692. In some examples, a first minimum distance D3 separates electrode 670 and strut 692 (which may be a respective nearest strut to electrode 670), and a second minimum distance D4 separates a distal portion of projection 696 of electrode attachment element 694 and strut 692 (which may also be the respective nearest strut to projection 696), where first minimum distance D3 is greater than second minimum distance D4. In this way, where first minimum distance D3 is greater than second minimum distance D4, the distal portion of projection 696 (e.g., the portion of projection 696 that does not include electrode 670 disposed over projection 696) is configured to contact strut 692 before electrode 670 contacts strut 692, thereby maintaining physical separation between electrode 670 and strut 692 (e.g., even when a force is applied to electrode attachment element 694 that would cause projection 696 and electrode 670 to move toward strut 692). In this way, first minimum distance D3 being greater than second minimum distance D4 can facilitate physical isolation and / or electrical isolation of electrode 670 (e.g., an outer surface of electrode 670) and strut 692. As a radially inward surface of electrode 670 can be electrically insulated from projection 696 (e.g., via an electrically insulative material and / or coating positioned between electrode 670 and projection 696), both the radially inward and radially outward surfaces of electrode 670 can be electrically insulated and / or isolated from both of projection 696 and strut 692.

[0187] In some examples, electrode attachment element 694 is sized, shaped, and / or otherwise configured to facilitate loading of electrode 670 onto projection 696 as well as retain electrode 670 on projection 696. For example, where electrode 670 includes a lumen that is configured to receive projection 696 of electrode attachment element 694, at least a portion ofelectrode attachment element 694 can be configured to facilitate relatively easier loading of electrode 670 onto projection 696. Additionally or alternatively, where electrode 670 includes a lumen that is configured to receive projection 696 of electrode attachment element 694, at least a portion of electrode attachment element 694 can be configured to retain electrode 670 on projection 696 once electrode 670 has been loaded onto projection 696. For example, in some examples, at least a portion of electrode attachment element 694 is configured to flex away from strut 692 (e.g., which may be a respective nearest strut to electrode attachment element 694) to facilitate mechanical coupling of electrode 670 to electrode attachment element 694. As electrode 670 may not otherwise be configured (e.g., sized) to clear a gap between electrode attachment element 694 and strut 692 (e.g., where the gap is at distal-most portion of projection 696, as indicated by second minimum distance D4 in FIG. 6A), having a portion of projection 696 (e.g., a distal portion) being configured to flex away from strut 692 can facilitate easier loading of electrode 670 onto projection 696 (e.g., while still maintaining a relatively simply geometry of electrode 670, such as a cylindrical shape having a lumen that is configured to receive at least a portion of projection 696).

[0188] In some examples, projection 696 of electrode attachment element 694 is configured to limit or prevent movement of electrode 670 relative to projection 696 (e.g., such as to prevent electrode 670 from slipping off of projection 696). For example, once electrode 670 is disposed on projection 696, a minimum distance between projection 696 and strut 692 (e.g., minimum distance D4 in FIG. 6A) can be small enough to prevent electrode 670 from slipping off of (e.g., moving relative to) projection 696. In some examples, minimum distance D4 in FIG. 6A is larger than a thickness of a wall of electrode 670, such that electrode would not be able to slip off of projection 696 due to minimum distance D4 in FIG. 6A being larger than a wall thickness of electrode 670.

[0189] In some examples, the portion of electrode attachment 694 that is configured to flex away (e.g., bend away) from strut 692 such that projection 696 can receive electrode 670 includes structural features to enable electrode attachment element 694 to more easily flex away from strut 692 (e.g., to enable easier loading of electrode 670 onto projection 696). In some examples, as shown in the examples of FIG. 6 A and FIG. 6B, projection 696 defines a plurality of relief cuts 602. In some examples, relief cuts 602 include one or more notches in projection 696 that generally reduce the rigidity of the portion of projection 696 including the relief cuts, thereby enabling projection 696 to more easily flex away from strut 692. In some examples, relief cuts 602 are positioned along a portion of projection 696 that is configured to be straightened (e.g., such that projection 696 can receive electrode 670). Having relief cuts 602 in projection 696 can enable an electrode 670 having a suitable cross-sectional shape (e.g., with alumen, such as a cylindrical shape) to be loaded onto projection 696 (e.g., while the portion of relief cuts 602 is flexed away from strut 692), while still having a relatively small gap (e.g., minimum distance D4) between projection 696 of electrode attachment element 694 and strut 692. As discussed previously, the relatively small gap between projection 696 and strut 692 (e.g., once electrode 670 is loaded onto projection 696) can limit or prevent electrode 670 from moving relative to and / or slipping off of projection 696.

[0190] In some examples, relief cuts 602 additionally or alternatively enable projection 696 to flex toward strut 692 (e.g., once electrode 670 has been positioned on projection 696). For example, relief cuts 602 can enable at least a portion of projection 696 that is straight and / or parallel relative to strut 692 to receive electrode 670 and subsequently flex toward (e.g., bend toward) strut 692 once projection 696 has received electrode 670. Such ability to flex relative to strut 692 can facilitate relatively easier assembly (e.g., mechanical coupling) of projection 696 and electrode 670 (e.g., because of the greater physical space to load electrode 670 onto projection 696 when projection 696 is flexed away from strut 692).

[0191] FIG. 7 illustrates an example electrode attachment element 794, which is an example of any of electrode attachment elements 194 of FIG. 3 A and FIG. 3B, and / or any of the other electrode attachment elements described in this disclosure. In the example of FIG. 7, an electrode 770 (which may be an example of any of electrodes 170 of FIG. 3 A and 3B, or any of the other electrodes or other therapy delivery elements of this disclosure) is positioned on electrode attachment element 794.

[0192] As shown in the example of FIG. 7, electrode attachment element 794 includes a projection 796 that is mechanically coupled to and branches off of a strut 792. Projection 796 and strut 792 may be examples of projection 196 and one of struts 192 of FIG. 3 A, respectively. As shown in the example of FIG. 7, projection 796 branches off of strut 792 and extends substantially parallel to a portion of strut 792 (e.g., such that projection 796 generally forms a “L” shape). In some examples, as shown in the example of FIG. 7, projection 796 includes a first portion 797A (which may also be referred to as a proximal portion 797A) and second portion 797B (which may also be referred to as a distal portion 797B), where first portion 797A is directly mechanically coupled to strut 792 and extends in a direction away from (e.g., transverse to) strut 792 and second portion 797B is not directly connected to strut 792 and extends substantially parallel to strut 792. In some examples, electrode 770 is positioned on the second portion 797B of projection 796. In some examples, electrode 770 extends between a first face 771A and a second face 771B. Strut 792 may be a portion of an overall expandable structure (e.g., expandable structure 190 of FIG. 3A).

[0193] In some examples, electrode attachment element 794 includes one or more electrically insulative components that are configured to electrically insulate electrode 770 from projection 796 and / or strut 792. As one or more of projection 796 and / or strut 792 can include an electrically conductive material, including one or more electrically insulative components to electrically insulate electrode 770 from projection 796 and / or strut 792 can reduce or prevent energy loss due to electrical shorting between electrode 770 and one or more of projection 796 and / or strut 792 (e.g., that would otherwise be energy delivered to target tissue of a patient). For example, as shown in the example of FIG. 7, a first insulative portion 752 is positioned radially outside of projection 796 (e.g., radially outside of second portion 797B of projection 796) of electrode attachment element 794 and positioned radially inside of the electrode 770 (e.g., such as to electrically insulate a radially inward surface of electrode 770 from projection 796). First insulative portion 752 can be sized, shaped, and otherwise configured to be positioned within a lumen of electrode 770, such that first insulative portion 752 can electrically insulative a radially inward surface of electrode 770 from projection 796.

[0194] As another example, as shown in the example FIG. 7, a second insulative portion 754 is positioned radially outside of projection 796 (e.g., radially outside of second portion 797B of projection 796) of electrode attachment element 794 and positioned between first face 771 A of electrode 770 and first portion 797A of projection 796, such as to electrically insulate at least first face 771 A of electrode 770 from projection 796 (e.g., first portion 797A of projection 796). Second insulative portion 754 can be sized, shaped, and otherwise configured to be positioned radially outside of projection 796 of electrode attachment element 794 and positioned adjacent at least one end (e.g., face) of electrode 770. For example, second insulative portion 754 can be sized, shaped, and otherwise configured to abut first face 771 A of electrode 770. In some examples, second insulative portion 754 defines a maximum outer dimension that is greater than an inner dimension of electrode 770 (e.g., such that when each of second insulative portion 754 and electrode 770 are positioned on projection 796, at least a portion of second insulative portion 754 contacts an end face of electrode 770, such as first face 771 A).

[0195] In some examples, second insulative portion 754 is configured to act as a bumper between electrode 770 and a portion of projection 796 (e.g., first portion 797A of projection 796). For example, in some examples, second insulative portion 754 is configured to be positioned between electrode 770 and first portion 797A of projection 796 such as to prevent contact between electrode 770 and first portion 797A of projection 796.

[0196] Each of first insulative portion 752 and second insulative portion 754 can include a suitable material configured to electrically insulate electrode 770 from one or more of projection 796 and / or strut 192. In some examples, each of first insulative portion 752 and second insulativeportion 754 include a polymer. For example, each of first insulative portion 752 and second insulative portion 754 can include a thermoplastic polyurethane (TPU), polycarbonate urethane (PCU), silicone, polypropylene, polyethylene, polystyrene, or polyetheretherketone (PEEK), another polymer, another suitable electrically insulative material (e.g., non-polymer), and / or any suitable combination or sub-combination thereof.

[0197] While first insulative portion 752 and second insulative portion 754 are shown as separate components in the example of FIG. 7, in other examples, first insulative portion 752 and second insulative portion 754 can be a single, continuous piece of electrically insulative material. For example, first insulative portion 752 and second insulative portion 754 can be a single piece of material that is configured to electrically insulate a radially inward surface of electrode 770 from projection 796 as well as electrically insulate at least one outer face (e.g., face 771 A) of electrode 770 from projection 796.

[0198] FIG. 8 illustrates an example expandable structure 890, which is an example of expandable structure 19 of FIG. 1 and / or expandable structure 190 of FIG. 3A and FIG. 3B. The example of FIG. 8 illustrates expandable structure 890 in a two-dimensional view (e.g., as though the tubular body of expandable structure 890 were cut and laid flat in a two-dimensional plane).

[0199] Expandable structure 890 of FIG. 8 can be configured similarly to expandable structure 190 of FIG. 3 A and FIG. 3B, and / or expandable structure 490 of FIG. 4A and FIG. 4B, except as described herein. In some examples, a tubular body portion of expandable structure 890 extends between a tubular body proximal end 890A and a tubular body distal end 890B. In some examples, as shown in the example of FIG. 8, expandable structure 890 includes a plurality of struts 892 (which may be an example of struts 192 in the example of FIG. 3 A). In some examples, as shown in the example of FIG. 8, expandable structure 890 includes a plurality of connection elements 864 between (e.g., located axially between) at least some of struts 892. Connection elements 864 may be integrally formed with struts 892 (e.g., include the same material as struts 892), but may be configured to move (e.g., expand, elongated, or the like) different than struts 892, as described herein. Connection elements 864 may be configured similar to connection elements 464 of FIG. 4A except as described herein. Expandable structure 890 also includes a plurality of electrode attachment elements 894, which may be examples of electrode attachment elements 194 of FIG. 3 A, electrode attachment elements 494 of FIG. 4A and FIG. 4B, or any of the other electrode attachment elements described in this disclosure. Each of electrode attachment elements 894 can be configured to receive at least one electrode (e.g., such as one or more of electrodes 170 of FIG. 3 A, or any of the other electrodes described in this disclosure), such as to facilitate mechanical coupling of one or more electrodes to expandable structure 890.

[0200] In the example of FIG. 8, expandable structure 890 defines a plurality of different sections, wherein each section is represented as a column extending in the positive and negative y-axis directions according to the orthogonal x-y-z axes in the example of FIG. 8. In other words, each section of expandable structure 890 includes a portion of expandable structure 890 located at a particular axial location and / or spanning an axial distance (e.g., along the x-axis) and extending around a central longitudinal axis 811 of expandable structure 890. In some examples, expandable structure 890 defines central longitudinal axis 811 (e.g., such that longitudinal axis 811 extends through a radial center of expandable structure 890), and each section extends around longitudinal axis 811 (e.g., in a circumferential direction around longitudinal axis 811). For example, expandable structure 890 defines a plurality of electrode attachment sections 852 (shown individually as electrode attachment section 852A, electrode attachment section 852B, electrode attachment section 852C, electrode attachment section 852D, and electrode attachment section 852E, but collectively referred to herein as electrode attachment sections 852). Each of electrode attachment sections 852 can include one or more electrode attachment elements 894 (e.g., each of which may be configured to receive one or more electrodes). In the example of FIG. 8, each of electrode attachment section 852A, electrode attachment section 852B, electrode attachment section 852C, electrode attachment section 852D, and electrode attachment section 852E includes at least three electrode attachment elements 894. However, each of electrode attachment sections 852 can include any suitable number of electrode attachment elements 894 (e.g., one, two, three, four, five, six, ten, or more electrode attachment elements 894, or any suitable number therebetween).

[0201] In some examples, expandable structure 890 defines one or more additional sections (e.g., other than electrode attachment sections 852). In some examples, expandable structure 890 defines a proximal-most section 856 (e.g., which is located proximal to all electrode attachment sections 852). In some examples, expandable structure 890 defines at least one intermediate section 858. In some examples, intermediate section 858 does not include any electrode attachment elements 894 and is positioned between proximal-most section 856 and a proximal- most one of electrode attachment sections 852 (e.g., electrode attachment section 852E in the example of FIG. 8). In some examples, expandable structure 890 includes more than one or intermediate section 858 (e.g., that are interspersed between two or more of electrode attachment sections 852). In some examples, as shown in the example of FIG. 8, each of proximal-most section 856 and intermediate section 858 do not include any electrode attachment elements.

[0202] In some examples, as shown in the example of FIG. 8, each of electrode attachment sections 852, proximal-most section 856, and intermediate section 858 includes a subset of struts 892 that define (e.g., form) a respective plurality of proximal crowns 893 and a plurality of distalcrowns 895 (only a portion of proximal crowns 893 and plurality of distal crowns 895 labeled in FIG. 8). Each of proximal crowns 893 and distal crowns 895 of each of electrode attachment sections 852, proximal-most section 856, and intermediate section 858 can include a vertex where two or more of struts 892 intersect to form a respective proximal apex or distal apex. In some examples, one or more of each of electrode attachment sections 852 include at least ten distal crowns 895. In some examples, one or more of each of electrode attachment sections 852 include at least ten proximal crowns 895.

[0203] As shown in the example of FIG. 8, expandable structure 890 defines a plurality of connection sections 862 (e.g., shown individually as connection section 862 A, connection section 862B, connection section 862C, connection section 862D, connection section 862E, and connection section 862F, collectively referred to herein as connection sections 862). In some examples, each of connection sections 862 are axially interspersed between at least two of electrode attachment sections 852, intermediate section 858, and / or proximal-most section 856 such that connection elements 864 of each of connection sections 862 are configured to mechanically couple axially adjacent ones of electrode attachment sections 852, intermediate section 858, and / or proximal-most section 856. As shown in the example of FIG. 8, connection sections 862 do not have any electrodes attached to any of connection sections 862.

[0204] In the example of FIG. 8, expandable structure 890 includes a radiopaque distal extension 898, which may be an example of radiopaque distal extension 198 of FIG. 3 A and FIG. 3B, radiopaque distal extension 498 of FIG. 4A, or any of the other radiopaque distal extension described in this disclosure. In some examples, radiopaque distal extension 898 is mechanically coupled to and extends from one of struts 892 of a distal-most electrode attachment section 852A. In some examples, radiopaque distal extension 898 is mechanically coupled to one of distal crowns 895 of electrode attachment section 852A. In some examples, at least a portion of radiopaque distal extension 898 includes a radiopaque or radiographic material that is visible via a suitable medical imaging modality (e.g., fluoroscopy). In some examples, a distal-most portion of radiopaque distal extension 898 includes the radiopaque or radiographic material. As discussed previously, in some examples, radiopaque distal extension 898 is configured to indicate a radial direction faced by electrodes that are mechanically coupled to expandable structure 890 (e.g., via electrode attachment elements 894).

[0205] In some examples, as shown in the example of FIG. 8, expandable structure 890 includes a radiopaque portion 813 positioned axially between tubular body proximal end 890 A and a proximal-most electrode attachment section 852E. As shown in the example of FIG. 8, radiopaque portion 813 is positioned in intermediate section 858 (e.g., wherein intermediate section is positioned between a proximal-most electrode attachment section 852 and proximal-most section 856). In some examples, such as where expandable structure is not fully advanced distally of a delivery catheter (e.g., delivery catheter 142 of FIG. 3B), radiopaque portion 813 indicates to a user (e.g., a clinician) that all of electrode attachment sections 852 (including the electrodes attached to each of the electrode attachment sections 852) have been advanced distally of the delivery catheter (e.g., delivery catheter 142 of FIG. 3B). In instances where expandable structure 890 is not fully advanced distally of the delivery catheter (e.g., such as in trial periods and / or periods of temporary therapy delivery where expandable structure 890 is not left to be implanted within the vasculature), having radiopaque portion 813 distal of tubular body proximal end 890A can enable a user (e.g., a clinician) to visualize expandable structure 890 in a way such that radiopaque portion 813 indicates expandable structure 890 is not advanced completely distal to the delivery catheter. In some cases, advancing expandable structure 890 completely distally of the delivery catheter limits or prevents expandable structure 890 from being re-sheathed (e.g., retracted proximally) into the delivery catheter. Thus, having radiopaque portion 813 distal of tubular body proximal end 890A can facilitate (e.g., make relatively easier) re-sheathing expandable structure 890 with a delivery catheter (e.g., subsequent to at least a portion of expandable structure 890 being advanced distally of the delivery catheter).

[0206] Radiopaque portion 813 can have suitable shape, size, and / or configuration. In some examples, radiopaque portion 813 defines a similar size, shape, and or configuration to that of electrode attachment elements 894. For example, radiopaque portion 813 can include a projection branching off of at least one of struts 892. In some examples, the projection of radiopaque portion 813 includes a radiopaque material. In other examples, the projection of radiopaque portion 813 is configured to receive a separate structure that is radiographic or radiopaque. In some examples, radiopaque portion 813 include a radiopaque structure affixed to one of struts 892 (e.g., one of struts 892 of intermediate section 858). In some examples, radiopaque portion 813 include a radiopaque coating applied to one of one of struts 892 (e.g., one of struts 892 of intermediate section 858). In some examples, expandable structure 890 includes more than one of radiopaque portion 813 (e.g., multiple of radiopaque portion 813 within intermediate section 858 and circumferentially spaced around expandable structure 890 about longitudinal axis 811).

[0207] The example of expandable structure 890 of FIG. 8 is an example of an expandable structure in which all respective proximal crowns 893 and all respective distal crowns 895 are mechanically coupled between adjacent sections (e.g., between adjacent sections of electrode attachment sections 852, intermediate section 858, and / or proximal-most section 856). Such a configuration is otherwise referred to herein as a “closed-cell” configuration. In other examples herein, less than all respective proximal crowns and respective distal crowns are mechanically coupled between adjacent sections, which can otherwise be referred to herein as a “open-cell”configuration. Further, in some examples herein, an expandable structure includes some adjacent sections with all respective proximal crowns and respective distal crowns connected while other sections include less than all respective proximal crowns and respective distal crowns connected, which can otherwise be referred to herein as a “hybrid-cell” configuration.

[0208] FIG. 9 illustrates an example expandable structure 990, which is an example of expandable structure 19 of FIG. 1 and / or expandable structure 190 of FIG. 3A and FIG. 3B. The example of FIG. 9 illustrates expandable structure 990 in a two-dimensional view (e.g., as though the tubular body of expandable structure 990 were cut and laid flat in a two-dimensional plane). As described more fully below, expandable structure 990 is considered an example of an “opencell” configuration (e.g., where axially adjacent sections of expandable structure 990 have less than all crowns connected).

[0209] Expandable structure 990 of FIG. 9 can be configured similarly to expandable structure 190 of FIG. 3 A and FIG. 3B, and / or expandable structure 490 of FIG. 4A and FIG. 4B, except as described herein. In some examples, a tubular body portion of expandable structure 990 extends between a tubular body proximal end 990A and a tubular body distal end 990B. In some examples, as shown in the example of FIG. 9, expandable structure 990 includes a plurality of struts 992 (e.g., which may be an example of struts 192 in the example of FIG. 3 A). In some examples, as shown in the example of FIG. 9, expandable structure 990 includes a plurality of connection elements 964 between (e.g., located axially between) at least some of struts 992. Connection elements 964 may be integrally formed with struts 992 (e.g., include the same material as struts 992), but may be configured to move (e.g., expand, elongated, or the like) different than struts 992, as described herein. Connection elements 964 may be configured similar to connection elements 464 of FIG. 4A except as described herein. For example, as shown in the example of FIG. 9, connection elements 964 are substantially straight (e.g., substantially straight between respective proximal crowns 993 and respective distal crowns 995). Expandable structure 990 also includes a plurality of electrode attachment elements 994, which may be examples of electrode attachment elements 194 of FIG. 3 A, electrode attachment elements 494 of FIG. 4A and FIG. 4B, or any of the other electrode attachment elements described in this disclosure. Each of electrode attachment elements 994 can be configured to receive at least one electrode (e.g., such as one or more of electrodes 170 of FIG. 3A, or any of the other electrodes described in this disclosure), such as to facilitate mechanical coupling of one or more electrodes to expandable structure 990.

[0210] In the example of FIG. 9, expandable structure 990 defines a plurality of different sections, wherein each section is represented as a column extending in the positive and negative y-axis directions according to the orthogonal x-y-z axes in the example of FIG. 9. In other words,each section of expandable structure 990 includes a portion of expandable structure 990 located at a particular axial location and / or spanning an axial distance (e.g., along the x-axis) and extending around a central longitudinal axis 911 of expandable structure 990. In some examples, expandable structure 990 defines central longitudinal axis 911 (e.g., such that longitudinal axis 911 extends through a radial center of expandable structure 990), and each section extends around longitudinal axis 911 (e.g., in a circumferential direction around longitudinal axis 911). As shown in the example of FIG. 9, expandable structure 990 defines a plurality of electrode attachment sections 952 (shown individually as electrode attachment section 952A, electrode attachment section 952B, electrode attachment section 952C, and electrode attachment section 952D, but collectively referred to herein as electrode attachment sections 952). Each of electrode attachment sections 952 can include one or more electrode attachment elements 994 (e.g., each of which may be configured to receive one or more electrodes). Electrode attachment elements 994 can be examples of electrode attachment elements 194 of FIG. 3 A, electrode attachment elements 494 of FIG. 4A and FIG. 4B, or any of the other electrode attachment elements in this disclosure. For example, each electrode attachment element 994 can include a projection branching off one of struts 992, the projection configured to mechanically couple to one or more electrodes (e.g., by receiving an electrode).

[0211] In the example of FIG. 9, each of electrode attachment section 952 A, electrode attachment section 952B, electrode attachment section 952C, and electrode attachment section 952D includes three electrode attachment elements 994. However, each of electrode attachment sections 952 can include any suitable number of electrode attachment elements 994 (e.g., one, two, three, four, five, six, ten, or more electrode attachment elements 994, or any suitable number therebetween).

[0212] In some examples, expandable structure 990 defines one or more additional sections (e.g., other than electrode attachment sections 952). In some examples, expandable structure 990 defines sections 956 (shown individually as section 956A, section 956B, section 956C, section 956D, section 956E, and section 956F, but collectively referred to herein as sections 956). In some examples, as shown in the example of FIG. 9, none of sections 956 include any electrode attachment elements 994, and therefore are not configured to mechanically couple to and do not include any electrodes.

[0213] As shown in the example of FIG. 9, each of electrode attachment sections 952 and sections 956 are disposed at respective axial locations along central longitudinal axis 911 of expandable structure 990. In some examples, expandable structure 990 includes at least some of sections 956 both proximal to and distal to all of electrode attachment sections 952. For example, as shown in FIG. 9, expandable structure 990 includes a pair of connected sections 956 (e.g.,section 956A and section 956B) distal to all of electrode attachment sections 952. As shown in FIG. 9, expandable structure 990 includes four of sections 956 (e.g., section 956C, section 956D, section 956E, and section 956F) that are successively connected to each other and proximal to electrode attachment sections 952. In other examples, expandable structure 990 includes more or less sections 956 proximal to and / or distal to electrode attachment sections 952.

[0214] In some examples, as shown in the example of FIG. 9, each of electrode attachment sections 952 and sections 956 includes a subset of struts 992 that define (e.g., form) a respective plurality of proximal crowns 993 and a plurality of distal crowns 995 (only a portion of proximal crowns 993 and plurality of distal crowns 995 labeled in FIG. 9). Each of proximal crowns 993 and distal crowns 995 of each of electrode attachment sections 952 and sections 956 can include a vertex where two or more of struts 992 intersect to form a respective proximal apex or distal apex. As shown in the example of FIG. 9, each of electrode attachment sections 952 and sections 956 includes twelve distal crowns 995 and twelve proximal crowns 993. However, as discussed with respect to expandable structure 490 of FIG. 4A and FIG. 4B, each of electrode attachment sections 952 and sections 956 can include any suitable number of crowns.

[0215] As shown in the example of FIG. 9, expandable structure 990 defines a plurality of connection sections 962 (e.g., shown individually as connection section 962 A, connection section 962B, connection section 962C, connection section 962D, connection section 962E, connection section 962F, connection section 962G, connection section 962H, and connection section 9621, collectively referred to herein as connection sections 962). In some examples, each of connection sections 962 are axially interspersed between at least two of electrode attachment sections 952 and / or sections 956, such that connection elements 964 of each of connection sections 962 are configured to mechanically couple axially adjacent ones of electrode attachment sections 952 and / or sections 956. As shown in the example of FIG. 9, connection sections 962 do not have any electrodes attached to any of connection sections 962.

[0216] In the example of FIG. 9, the number of respective connected crowns between pairs of respective electrode attachment sections 952 and / or sections 956 varies over the length of expandable structure 990 (e.g., along central longitudinal axis 911 of expandable structure 990). In other words, pairs of electrode attachment sections 952 and / or sections 956 have different fractions of connected crowns to total crowns (e.g., where the number of total crowns is equal to the number of connected crowns and unconnected crowns), such that the fraction of connected crowns to total crowns of different pairs of sections varies over the length of expandable structure 990 (e.g., along central longitudinal axis 911 of expandable structure 990). As used herein, fractions of crowns (e.g., fractions of connected crowns to total crowns) are expressed as a quotient (e.g., one-quarter, one-half), however it is understood that fractions can be expressedas a number over another number (e.g., number of connected crowns over a number of total crowns). This variation in the number and / or fraction of connected crowns to total crowns between different sections of electrode attachment sections 952 and / or sections 956 can enable some sections to be relatively more flexible (e.g., relatively greater bending flexibility) or relatively more rigid (e.g., relatively lesser bending flexibility) as compared to other sections of electrode attachment sections 952 and / or sections 956.

[0217] For example, as shown in the example of FIG. 9, expandable structure 990 includes a first pair of axially adjacent sections including at least a first section (e.g., section 956A) and a second section (e.g., section 956B) and a second pair of axially adjacent sections including at least a third section (e.g., electrode attachment section 952A) and a fourth section (e.g., electrode attachment section 952B). Respective crowns of each of the first pair and second pair of sections are connected according to different fractions of connected proximal crowns 993 to total proximal crowns 993. The first pair of axially adjacent sections are mechanically coupled such that some proximal crowns 993 of the first section (e.g., section 956A) are connected to at least some distal crowns 995 of the second section (e.g., section 956B) according to a first fraction of connected proximal crowns 993 (e.g., proximal crowns 993 of section 956A that are connected to respective distal crowns 995 of section 956B) to total proximal crowns 993 of the first section (e.g., section 956A). As shown in the example of FIG. 9, the first fraction of connected proximal crowns 993 to total proximal crowns 993 of the first section (e.g., section 956A) is one-half (i.e., six connected proximal crowns 993 divided by twelve total proximal crowns 993 of section 956A). In other examples, the first fraction of connected proximal crowns 993 to total proximal crowns 993 of the first section is greater than one-half, such that the first fraction of connected proximal crowns 993 to total proximal crowns 993 of the first section (e.g., section 956A) is greater than or equal to one-half.

[0218] The second pair of axially adjacent sections (e.g., including electrode attachment section 952A and electrode attachment section 952B) are mechanically coupled such that some proximal crowns 993 of the third section (e.g., electrode attachment section 952A) are connected to at least some distal crowns 995 of the fourth section (e.g., electrode attachment section 952B) according to a second fraction of connected proximal crowns 993 (e.g., proximal crowns 993 of electrode attachment section 952A that are connected to respective distal crowns 995 of electrode attachment section 952B) to total proximal crowns 993 of the third section (e.g., electrode attachment section 952 A). As shown in the example of FIG. 9, the second fraction of connected proximal crowns 993 to total proximal crowns 993 of the third section (e.g., electrode attachment section 952A) is one-third (i.e., four connected proximal crowns 993 divided by twelve total proximal crowns 993 of electrode attachment section 952A). In other examples, the secondfraction of connected proximal crowns 993 to total proximal crowns 993 of the third section is less than one-half, such that the second fraction of connected proximal crowns 993 to total proximal crowns 993 of the third section (e.g., electrode attachment section 952A) is less than or equal to one-half. In some examples, the second fraction (e.g., connected proximal crowns 993 to total proximal crowns 993 of the third section, such as electrode attachment section 952A) is one- quarter to one-half, or any suitable fraction therebetween.

[0219] In the example of FIG. 9, for each pair of connected sections, respective pairs of connected proximal crowns 993 and distal crowns 995 are evenly distributed around expandable structure 990. For example, for the first pair of sections including section 956A and section 956B, connected proximal crowns 993 and distal crowns 995 are evenly distributed around the circumference of expandable structure 990 (e.g., in a direction around central longitudinal axis 911) with unconnected proximal crowns 993 and distal crowns 995 evenly interspersed between the connected proximal crowns 993 and distal crowns 995. In the example of FIG. 9 and for the first pair of sections including section 956A and section 956B, every other one of proximal crown 993 of section 956A is connected to a respective one of distal crowns 995 of section 956B. As another example, for the second pair of sections including electrode attachment section 952A and electrode attachment section 952B, connected proximal crowns 993 and distal crowns 995 are evenly distributed around the circumference of expandable structure 990 (e.g., in a direction around central longitudinal axis 911) with unconnected proximal crowns 993 and distal crowns 995 evenly interspersed between the connected proximal crowns 993 and distal crowns 995. In the example of FIG. 9 and for the second pair of sections including electrode attachment section 952A and electrode attachment section 952B, every third one of proximal crown 993 of electrode attachment section 952A is connected to a respective one of distal crowns 995 of electrode attachment section 952B. Having respective pairs of connected proximal crowns 993 and distal crowns 995 for adjacent sections of expandable structure 990 evenly distributed around expandable structure 990 can facilitate uniform radial expansion and deployment of expandable structure 990 (e.g., when expandable structure 990 is advanced distally of a delivery catheter and permitted to expand).

[0220] In other examples, respective pairs of connected proximal crowns 993 and distal crowns 995 are not evenly distributed around expandable structure 990. In some examples, the uneven distribution of connected crowns around expandable structure 990 can facilitate reinforcement of particular circumferential portions of expandable structure 990 as opposed to other circumferential portions. For example, a relatively higher or lower density of connected crowns can be positioned adjacent electrode attachment elements 994 of any or all of electrodeattachment section 952A, electrode attachment section 952B, electrode attachment section 952C, and / or electrode attachment section 952D.

[0221] In the example of FIG. 9, the first pair of sections including section 956A and section 956B, which may be a distal-most pair of sections of expandable structure 990 (e.g., distal to all other sections of the plurality of sections of expandable structure 990), may be relatively more rigid (e.g., because of the relatively greater number of connected crowns between sections) as opposed to other, more proximal pairs of sections, such as the second pair of sections including electrode attachment section 952 A and electrode attachment section 952B. For example, as discussed above, the first fraction (e.g., one-half) of connected proximal crowns 993 to total proximal crowns 993 corresponding to the first pair of sections including section 956A and section 956B is greater than the second fraction (e.g., one-third) of connected proximal crowns 993 to total proximal crowns 993 corresponding to the second pair of sections including electrode attachment section 952A and electrode attachment section 952B, which causes the second pair of sections including electrode attachment section 952A and electrode attachment section 952B to be relatively more flexible and / or less rigid than the first pair of sections including section 956A and section 956B. This relatively greater rigidity of the distal-most pair of sections including section 956A and section 956B can help anchor expandable structure 990 within a blood vessel when expandable structure 990 is initially advanced distally relative to a delivery catheter (e.g., delivery catheter 142 in the example of FIG. 3B), such that expandable structure 990 is less likely to move (e.g., axially and or rotationally with respect to the blood vessel) as the remainder of expandable structure 990 is advanced distally of the delivery catheter and permitted to deploy (e.g., expand). Additionally or alternatively, the relatively higher fraction of connected crowns between section 956A and section 956B can cause these sections to exert a relatively greater outward radial force (e.g., against a blood vessel), such as compared to more proximal sections. However, the relatively greater flexibility and / or relatively lower rigidity of electrode attachment section 952 A and electrode attachment section 952B (e.g., relatively lower rigidity as compared to the first pair of sections including section 956A and section 956B) can enable some sections of expandable structure 990 (e.g., sections of expandable structure 990 configurated to carry electrodes) to better conform to vasculature of a patient.

[0222] While the first pair of sections including section 956A and section 956B are described as being a distal-most pair of sections in the above example, in other examples, the first pair of sections that has relatively more connected crowns (e.g., and thus is relatively more rigid as compared to some other pairs of sections) is a proximal-most pair of sections of expandable structure 990 (e.g., proximal to all other sections of the plurality of sections of expandable structure 990). For example, as shown in the example of FIG. 9, expandable structure 990includes a third pair of axially adjacent sections including at least a fifth section (e.g., section 956E) and a sixth section (e.g., section 956F). Respective crowns of each section of the third pair of section (e.g., including section 956E and section 956F) are connected according to a third fraction of connected proximal crowns 993 to total proximal crowns 993 (e.g., wherein the third fraction is the same or different as one or more of the first fraction or the second fraction described above). For example, the third pair of axially adjacent sections are mechanically coupled such that some proximal crowns 993 of the fifth section (e.g., section 956E) are connected to at least some distal crowns 995 of the sixth section (e.g., section 956E) according to the third fraction of connected proximal crowns 993 (e.g., proximal crowns 993 of section 956E that are connected to respective distal crowns 995 of section 956F) to total proximal crowns 993 of the fifth section (e.g., section 956E).

[0223] As shown in the example of FIG. 9, the third fraction of connected proximal crowns 993 to total proximal crowns 993 of the fifth section (e.g., section 956E) is one-half (i.e., six connected proximal crowns 993 divided by twelve total proximal crowns 993 of section 956E). In other examples, the third fraction of connected proximal crowns 993 to total proximal crowns 993 of the fifth section (e.g., section 956E) is greater than one-half, such that the third fraction of connected proximal crowns 993 to total proximal crowns 993 of the fifth section (e.g., section 956E) is greater than or equal to one-half. In some examples, the third fraction (e.g., corresponding to third pair of sections, which may be a proximal-most pair of sections, including section 956E and section 956F) is equal to the first fraction (e.g., wherein the first fraction corresponds to the first pair of sections, which may be a distal-most pair of sections, including section 956A and section 956).

[0224] As described above with respect to the distal-most pair of sections (e.g., section 956A and section 956B), the third pair of sections (e.g., section 956E and section 956F), which may be a proximal-most pair of sections, may be relatively more rigid as compared to other sections (e.g., the second pair of sections including electrode attachment section 952 A and electrode attachment section 952B) because of a greater fraction of connected crowns 993 to total crowns 993. For example, the third fraction (e.g., one-half) of connected proximal crowns 993 to total proximal crowns 993 corresponding to the third pair of sections including section 956E and section 956F is greater than the second fraction (e.g., one-third) of connected proximal crowns 993 to total proximal crowns 993 corresponding to the second pair of sections including electrode attachment section 952A and electrode attachment section 952B, which causes the second pair of sections including electrode attachment section 952A and electrode attachment section 952B to be relatively more flexible and / or less rigid than the third pair of sections including section 956E and section 956F. This relatively greater rigidity of the proximal-most pair of sections includingsection 956E and section 956B can help anchor expandable structure 990 within a blood vessel when expandable structure 990 is fully advanced distally relative a delivery catheter (e.g., delivery catheter 142 in the example of FIG. 3B), such that expandable structure 990 is less likely to move (e.g., axially and or rotationally with respect to the blood vessel) once the entire length of expandable structure 990 is deployed with the blood vessel.

[0225] In some examples, the relatively higher rigidity of both of the first pair of sections including section 956A and section 956B, which may be a distal-most pair of sections and the third pair of sections including section 956E and section 956F, which may be a proximal-most pair of sections, together help anchor expandable structure 990 within vasculature of a patient once expandable structure 990 is fully advanced distally of a delivery catheter and permitted to deploy. For example, as shown in the example of FIG. 9, the second pair of axially adjacent sections (e.g., including electrode attachment section 952A and electrode attachment section 952B) is positioned axially between the first pair of axially adjacent sections (e.g., including section 956A and section 956B) and the third pair of actually adjacent sections (e.g., including section 956E and section 956F). In some examples, as shown in the example of FIG. 9, the first pair of sections including section 956A and section 956B are distal to all other sections of expandable structure 990 and the third pair of sections including section 956E and section 956F are proximal to all other sections of expandable structure 990.

[0226] While the example of FIG. 9 as described above is illustrated in terms of the number and / or fraction of crowns connected for a first pair of sections (e.g., section 956A and section 956B), a second pair of sections (e.g., electrode attachment section 952A and electrode attachment section 952B), and a third pair of sections (e.g., section 956E and section 956F), expandable structure 990 can have any number of sections and / or number of pairs of sections (e.g., that are connected according to any suitable fraction of connected crowns).

[0227] FIG. 10 illustrates an example expandable structure 1090, which is an example of expandable structure 19 of FIG. 1 and / or expandable structure 190 of FIG. 3A and FIG. 3B. The example of FIG. 10 illustrates expandable structure 1090 in a two-dimensional view (e.g., as though the tubular body of expandable structure 1090 were cut and laid flat in a two-dimensional plane). As described more fully below, expandable structure 1090 is considered an example of a “hybrid-cell” configuration (e.g., where at some axially adjacent sections of expandable structure 1090 have all crowns connected and where other axially adjacent sections of expandable structure 1090 have less than all crowns connected).

[0228] Expandable structure 1090 of FIG. 10 can be configured similarly to expandable structure 190 of FIG. 3 A and FIG. 3B, expandable structure 490 of FIG. 4A and FIG. 4B, expandable structure 990 of FIG. 9, and / or any of the other expandable structures of thisdisclosure, except as described herein. In some examples, a tubular body portion of expandable structure 1090 extends between a tubular body proximal end 1090A and a tubular body distal end 1090B. In some examples, as shown in the example of FIG. 10, expandable structure 1090 includes a plurality of struts 1092 (e.g., which may be an example of struts 192 in the example of FIG. 3 A). In some examples, as shown in the example of FIG. 10, expandable structure 1090 includes a plurality of connection elements 1064 between (e.g., located axially between) at least some of struts 1092. Connection elements 1064 may be integrally formed with struts 1092 (e.g., include the same material as struts 1092), but may be configured to move (e.g., expand, elongated, or the like) different than struts 1092, as described herein. Connection elements 1064 may be configured similar to connection elements 464 of FIG. 4 A except as described herein. For example, as shown in the example of FIG. 10, connection elements 1064 are substantially straight (e.g., substantially straight between respective proximal crowns 1093 and respective distal crowns 1095). Expandable structure 1090 also includes a plurality of electrode attachment elements 1094, which may be examples of electrode attachment elements 194 of FIG. 3 A, electrode attachment elements 494 of FIG. 4A and FIG. 4B, or any of the other electrode attachment elements described in this disclosure. Each of electrode attachment elements 1094 can be configured to receive at least one electrode (e.g., such as one or more of electrodes 170 of FIG. 3 A, or any of the other electrodes described in this disclosure), such as to facilitate mechanical coupling of one or more electrodes to expandable structure 1090.

[0229] In the example of FIG. 10, expandable structure 1090 defines a plurality of different sections, wherein each section is represented as a column extending in the positive and negative y-axis directions according to the orthogonal x-y-z axes in the example of FIG. 10. In other words, each section of expandable structure 1090 includes a portion of expandable structure 1090 located at a particular axial location and / or spanning an axial distance (e.g., along the x-axis) and extending around a central longitudinal axis 1011 of expandable structure 1090. In some examples, expandable structure 1090 defines central longitudinal axis 1011 (e.g., such that longitudinal axis 1011 extends through a radial center of expandable structure 1090), and each section extends around longitudinal axis 1011 (e.g., in a circumferential direction around longitudinal axis 1011). As shown in the example of FIG. 10, expandable structure 1090 defines a plurality of electrode attachment sections 1052 (shown individually as electrode attachment section 1052A, electrode attachment section 1052B, electrode attachment section 1052C, and electrode attachment section 1052D, but collectively referred to herein as electrode attachment sections 1052). Each of electrode attachment sections 1052 can include one or more electrode attachment elements 1094 (e.g., each of which may be configured to receive one or more electrodes). In the example of FIG. 10, each of electrode attachment section 1052A, electrodeattachment section 1052B, electrode attachment section 1052C, and electrode attachment section 1052D includes three electrode attachment elements 1094. However, each of electrode attachment sections 1052 can include any suitable number of electrode attachment elements 1094 (e.g., one, two, three, four, five, six, ten, or more electrode attachment elements 1094, or any suitable number therebetween).

[0230] In some examples, expandable structure 1090 defines one or more additional sections (e.g., other than electrode attachment sections 1052). In some examples, expandable structure 1090 defines sections 1056 (shown individually as section 1056A, section 1056B, section 1056C, section 1056D, section 1056E, and section 1056F, but collectively referred to herein as sections 1056). In some examples, as shown in the example of FIG. 10, none of sections 1056 include any electrode attachment elements 1094, and therefore are not configured to mechanically couple to and do not include any electrodes.

[0231] As shown in the example of FIG. 10, each of electrode attachment sections 1052 and sections 1056 are disposed at respective axial locations along central longitudinal axis 1011 of expandable structure 1090. In some examples, expandable structure 1090 includes at least some of sections 1056 both proximal to and distal to all of electrode attachment sections 1052. For example, as shown in FIG. 10, expandable structure 1090 includes a pair of connected sections 1056 (e.g., section 1056A and section 1056B) distal to all of electrode attachment sections 1052. As shown in FIG. 10, expandable structure 1090 includes four of sections 1056 (e.g., section 1056C, section 1056D, section 1056E, and section 1056F) that are successively connected to each other and proximal to electrode attachment sections 1052. In other examples, expandable structure 1090 includes more or less sections 1056 proximal to and / or distal to electrode attachment sections 1052.

[0232] In some examples, as shown in the example of FIG. 10, each of electrode attachment sections 1052 and sections 1056 includes a subset of struts 1092 that define (e.g., form) a respective plurality of proximal crowns 1093 and a plurality of distal crowns 1095 (only a portion of proximal crowns 1093 and plurality of distal crowns 1095 labeled in FIG. 10). Each of proximal crowns 1093 and distal crowns 1095 of each of electrode attachment sections 1052 and sections 1056 can include a vertex where two or more of struts 1092 intersect to form a respective proximal apex or distal apex. As shown in the example of FIG. 10, each of electrode attachment sections 1052 and sections 1056 includes twelve distal crowns 1095 and twelve proximal crowns 1093. However, as discussed with respect to expandable structure 490 of FIG. 4A and FIG. 4B, each of electrode attachment sections 1052 and sections 1056 can include any suitable number of crowns.

[0233] As shown in the example of FIG. 10, expandable structure 1090 defines a plurality of connection sections 1062 (e.g., shown individually as connection section 1062 A, connection section 1062B, connection section 1062C, connection section 1062D, connection section 1062E, connection section 1062F, connection section 1062G, connection section 1062H, and connection section 10621, collectively referred to herein as connection sections 1062). In some examples, each of connection sections 1062 are axially interspersed between at least two of electrode attachment sections 1052 and / or sections 1056, such that connection elements 1064 of each of connection sections 1062 are configured to mechanically couple axially adjacent ones of electrode attachment sections 1052 and / or sections 1056. As shown in the example of FIG. 10, connection sections 1062 do not have any electrodes attached to any of connection sections 1062.

[0234] In the example of FIG. 10, the number of respective connected crowns between pairs of respective electrode attachment sections 1052 and / or sections 1056 varies over the length of expandable structure 1090 (e.g., along central longitudinal axis 1011 of expandable structure 1090). In other words, pairs of electrode attachment sections 1052 and / or sections 1056 have different fractions of connected crowns to total crowns (e.g., where the number of total crowns is equal to the number of connected crowns and unconnected crowns), such that the fraction of connected crowns to total crowns of different pairs of sections varies over the length of expandable structure 1090 (e.g., along central longitudinal axis 1011 of expandable structure 1090). This variation in the number and / or fraction of connected crowns to total crowns between different sections of electrode attachment sections 1052 and / or sections 1056 can enable some sections to be relatively more flexible or relatively more rigid as compared to other sections of electrode attachment sections 1052 and / or sections 1056.

[0235] For example, as shown in the example of FIG. 10, expandable structure 1090 includes a first pair of axially adjacent sections including at least a first section (e.g., section 1056A) and a second section (e.g., section 1056B) and a second pair of axially adjacent sections including at least a third section (e.g., electrode attachment section 1052A) and a fourth section (e.g., electrode attachment section 1052B). Respective crowns of each of the first pair and second pair of sections are connected according to different fractions of connected proximal crowns 1093 to total proximal crowns 1093. The first pair of axially adjacent sections are mechanically coupled such that all proximal crowns 1093 of the first section (e.g., section 1056A) are connected to respective ones of distal crowns 1095 of the second section (e.g., section 1056B) according to a first fraction of connected proximal crowns 1093 (e.g., proximal crowns 1093 of section 1056A that are connected to respective distal crowns 1095 of section 1056B) to total proximal crowns 1093 of the first section (e.g., section 1056A). As shown in the example of FIG. 10, the first fraction of connected proximal crowns 1093 to total proximal crowns 1093 of the first section(e.g., section 1056A) is one (i.e., all twelve connected proximal crowns 1093 divided by twelve total proximal crowns 1093 of section 1056A).

[0236] The second pair of axially adjacent sections (e.g., including electrode attachment section 1052 A and electrode attachment section 1052B) are mechanically coupled such that less than all proximal crowns 1093 of the third section (e.g., electrode attachment section 1052 A) are connected to at least some distal crowns 1095 of the fourth section (e.g., electrode attachment section 1052B) according to a second fraction of connected proximal crowns 1093 (e.g., proximal crowns 1093 of electrode attachment section 1052 A that are connected to respective distal crowns 1095 of electrode attachment section 1052B) to total proximal crowns 1093 of the third section (e.g., electrode attachment section 1052 A). As shown in the example of FIG. 10, the second fraction of connected proximal crowns 1093 to total proximal crowns 1093 of the third section (e.g., electrode attachment section 1052A) is one-third (i.e., four connected proximal crowns 1093 divided by twelve total proximal crowns 1093 of electrode attachment section 1052A). In other examples, the second fraction of connected proximal crowns 1093 to total proximal crowns 1093 of the third section is less than one-half, such that the second fraction of connected proximal crowns 1093 to total proximal crowns 1093 of the third section (e.g., electrode attachment section 1052A) is less than or equal to one-half. In some examples, the second fraction (e.g., connected proximal crowns 1093 to total proximal crowns 1093 of the third section, such as electrode attachment section 1052A) is one-quarter to one-half, or any suitable fraction therebetween.

[0237] In the example of FIG. 10, the first pair of sections including section 1056A and section 1056B, which may be a distal -most pair of sections of expandable structure 1090 (e.g., distal to all other sections of the plurality of sections of expandable structure 1090), may be relatively more rigid (e.g., because of the relatively greater number of connected crowns between sections) as opposed to other, more proximal pairs of sections, such as the second pair of sections including electrode attachment section 1052 A and electrode attachment section 1052B. For example, as discussed above, the first fraction (e.g., one) of connected proximal crowns 1093 to total proximal crowns 1093 corresponding to the first pair of sections including section 1056A and section 1056B is greater than the second fraction (e.g., one-third) of connected proximal crowns 1093 to total proximal crowns 1093 corresponding to the second pair of sections including electrode attachment section 1052 A and electrode attachment section 1052B, which causes the second pair of sections including electrode attachment section 1052 A and electrode attachment section 1052B to be relatively more flexible and / or less rigid than the first pair of sections including section 1056A and section 1056B. This relatively greater rigidity of the distal- most pair of sections including section 1056A and section 1056B can help anchor expandablestructure 1090 within a blood vessel when expandable structure 1090 is initially advanced distally relative to a delivery catheter (e.g., delivery catheter 142 in the example of FIG. 3B), such that expandable structure 1090 is less likely to move (e.g., axially and or rotationally with respect to the blood vessel) as the remainder of expandable structure 1090 is advanced distally of the delivery catheter and permitted to deploy (e.g., expand). However, the relatively greater flexibility and / or relatively lower rigidity of electrode attachment section 1052A and electrode attachment section 1052B (e.g., relatively lower rigidity as compared to the first pair of sections including section 1056A and section 1056B) can enable some sections of expandable structure 1090 (e.g., sections of expandable structure 1090 configurated to carry electrodes) to better conform to vasculature of a patient.

[0238] In the example of FIG. 10, the first pair of sections including section 1056A and section 1056B, which may be a distal -most pair of sections of expandable structure 1090 (e.g., distal to all other sections of the plurality of sections of expandable structure 1090), having all crowns connected can enable at least section 1056A and section 1056B of expandable structure 1090 to be re-sheathed (e.g., subsequent to being advanced distally of a delivery catheter, such as delivery catheter 142 in the example of FIG. 3B). Unlike open-cell configurations in which less than all crowns of axially adjacent section are connected such that unconnected crowns can catch and / or snag on a delivery catheter (e.g., delivery catheter 142 in the example of FIG. 3B), having all crowns connected between section 1056A and section 1056B can enable the distal -most portion of expandable structure 1090 including at least section 1056A and section 1056B to be re-sheathed (e.g., subsequent to being advanced distally of a delivery catheter). The ability to resheath at least the distal portion of expandable structure 1090 can enable a user (e.g., a clinician) to attempt multiple deployments of expandable structure (e.g., by advancing at least the distal portion of expandable structure 1090 distally of a delivery sheath), which may ultimately enable more accurate placement of expandable structure 1090 relative to a target location with vasculature of a patient. Such hybrid-cell configurations of expandable structure 1090 can enable at least some sections of the expandable structure 1090 (e.g., sections of a distal portion of expandable structure 1090) to be re-sheathed because all respective crowns of adjacent sections are connected, while other sections (e.g., electrode attachment section 1052A and electrode attachment section 1052B) are relatively more flexible because less than all respective crowns between adjacent sections are connected.

[0239] FIG. 11 and FIG. 12 illustrate an example connection element 1064 and connection element 1264 respectively, which can be examples of connection elements 464 of FIG. 4A and FIG. 4B, connection elements 864 of FIG. 8, and / or any of the other connection elements described in this disclosure.

[0240] In the example of FIG. 11, connection elements 1164 is connected to a proximal crown 1193 and a distal crown 1195 of adjacent sections of an expandable structure, each section including one or more of struts 1192. As shown in FIG. 11, connection elements 1164 defines an oval shape (e.g., which can include a circle shape).

[0241] As shown in FIG. 11, connection element 1164 is rotationally symmetric and / or reflectionally symmetric about an axial midpoint 1167 of connection element 1164. Axial midpoint 1167 is a midpoint of connection element 1164 in a longitudinal direction (e.g., along a direction parallel to the x-axis direction according to the orthogonal x-y-z axes in the example of FIG. 11). For example, the portion of connection element 1164 between distal crown 1195 and midpoint 1167 can be rotated around midpoint 1167 to define the portion of connection element 1164 between midpoint 1167 and proximal crown 1193, and is thus rotationally symmetric about midpoint 1167. Additionally or alternatively, the portion of connection element 1164 between distal crown 1195 and midpoint 1167 can be reflected across midpoint 1167 (e.g., in a plane formed by the x-axis and y-axis according to the orthogonal x-y-x axes in FIG. 11) to define the portion of connection element 1164 between midpoint 1167 and proximal crown 1193, and is thus reflectionally symmetric about axial midpoint 1167. As discussed in connection with FIG. 4A and FIG. 4B, having such rotational and / or reflectional symmetry can facilitate uniform expansion and / or extension of expandable structure 490.

[0242] In the example of FIG. 12, connection elements 1264 is connected to a proximal crown 1293 and a distal crown 1295 of adjacent sections of an expandable structure, each section including one or more of struts 1292. As shown in FIG. 12, connection element 1264 defines a u- shape (e.g., a shape with one curved section that forms a trough).

[0243] As shown in FIG. 12, connection element 1264 reflectionally symmetric about a plane 1215 extending through axial midpoint 1267 of connection element 1264. Axial midpoint 1267 is a midpoint of connection element 1264 in a longitudinal direction (e.g., along a direction parallel to the x-axis direction according to the orthogonal x-y-z axes in the example of FIG. 12). Plane 1215 is a plane parallel to the y-axis and z-axis and perpendicular to the x-axis according to the orthogonal x-y-z axes in FIG. 12. The portion of connection element 1264 between distal crown 1295 and midpoint 1267 can be reflected across plane 1215 to define the portion of connection element 1264 between midpoint 1167 and proximal crown 1293, and is thus reflectionally symmetric about plane 1215. While connection element 1264 is not itself rotationally or reflection symmetric about midpoint 1267, an expandable structure can include one or more of connection element 1264 in alternating configurations (e.g., such that alternating ones of connection element 1264 form a trough by extending in the negative y-axis direction as shown in FIG. 12 or form a peak by extending in the positive y-axis direction).

[0244] Each of FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D, FIG. 13E, FIG. 13F, FIG. 13G, and FIG. 13H illustrate example electrode layout configurations according to the techniques of this disclosure. The example electrode layout configurations can be applied to any of the devices of this disclosure. Each of FIG. 13 A through FIG. 13H illustrates a schematic diagram of an example expandable structure 1390 in a two-dimensional format, in which expandable structure 1390 extends between a proximal end 1390A and a distal end 1390B. Expandable structure 1390 is an example of expandable structure 19 of FIG. 1, expandable structure 190 of FIG. 3 A and FIG. 3B, expandable structure 490 of FIG. 4 A and FIG. 4B, or any of the other expandable structures described in this disclosure. Expandable structure 1390 defines a central longitudinal axis 1311 (e.g., where central longitudinal axis 1311 extends through a radial center of expandable structure 1390), which may be an example of central longitudinal axis 111 of FIG. 3 A and FIG. 3B, central longitudinal axis 411 of FIG. 4A, or any of the other longitudinal axes described in this disclosure.

[0245] The schematic diagrams of each of FIG. 13 A through FIG. 13H illustrate a plurality of electrodes 1370, where each of electrodes 1370 is positioned at a respective axial and circumferential location relative to expandable structure 1390. Electrodes 1370 can be examples of electrodes 17 of FIG. 1, electrodes 170 of FIG. 3 A and FIG. 3B, or any of the other electrodes described in this disclosure. For purposes of illustrating the different positional configurations of electrodes 1370 in each of FIG. 13A through FIG. 13H, positions of each of electrodes 1370 will be referenced as corresponding to “cells,” where multiple cells are arranged in respective “rows” (e.g., horizontal rows in a direction parallel to central longitudinal axis 1311) and respective “columns” (e.g., vertical columns extending a direction transverse to central longitudinal axis 1311). However, it should be understood that such terminology is for illustrative purposes, and that electrodes 1370 are understood to be positioned at respective axial and circumferentially spaced-apart locations relative to (e.g., along and / or around) expandable structure 1390 (e.g., wherein expandable structure 1390 includes a tubular, cylindrical, or another suitable three- dimensional structure). For example, each of FIG. 13 A through FIG. 13H illustrates a 5 by 5 grid of cells including 5 cells in each column of the grid and 5 cells in each row of the grid (e.g., where each cell includes a possible position for one of electrodes 1370 to be positioned), and electrodes 1370 are referred to as corresponding to respective cells within the 5 by 5 grid. The 5 by 5 grid of each of FIG. 13A through FIG. 13H includes labels for each row (e.g., row Rl, row R2, row R3, row R4, row R5, wherein each row is represents a respective circumferential position around expandable structure 1390, such as around a central longitudinal axis 1311) and labels for each column (e.g., column Cl, column C2, column C3, column C4, column C5, wherein column Cl is a distal-most column and column C2, column C3, column C4, column C5positioned successively proximal of column Cl), such that cells within the 5 by 5 grid can be referred to by a corresponding row and cell identifier.

[0246] In some examples, each of the cells (e.g., which can indicate a position of one of electrodes 1370) referred to in each of FIG. 13A through FIG. 13H corresponds to an axial and / or circumferentially positioning of a respective electrode attachment element that is configured to facilitate mechanical coupling of electrodes 1370 to expandable structure 1390. For example, each of the cells described with respect to the 5 by 5 grid in any of FIG. 13 A through FIG. 13H can correspond to a respective one of electrode attachment elements 194 of FIG. 3 A, electrode attachment elements 494 of FIG. 4A and FIG. 4B, electrode attachment elements 594 of FIG. 5 A and FIG. 5B, electrode attachment elements 894 of FIG. 8, or any of the other electrode attachment elements described in this disclosure.

[0247] In some examples, each of the cells (e.g., which can indicate a position of one of electrodes 1370) referred to in each of FIG. 13A through FIG. 13H corresponds to an axial and / or circumferentially spacing of a respective electrode attachment element and / or electrode 1370 that are mechanically coupled to expandable structure 1390. For example, each of the cells described with respect to the 5 by 5 grid in any of FIG. 13 A through FIG. 13H can correspond to a relative length (e.g., as measured along a central longitudinal axis 1311 of expandable structure 1390) and / or a relative width of electrodes 1370 (as measured in a direction transverse to central longitudinal axis 1311). For example, example configurations in which an empty cell (e.g., without one of electrodes 1370) separates axially adjacent cells with electrodes 1370 can indicate that the adjacent electrodes 1370 are separated by a distance greater than or equal to a length of one of electrodes 1370 (e.g., as measured along central longitudinal axis 1311). In some examples, example configurations in which a cell separates circumferentially adjacent cells with electrodes 1370 can indicate that the adjacent electrodes 1370 are separated by a distance greater than or equal to a width of one of electrodes 1370 (e.g., as measured in a direction transverse to central longitudinal axis 1311).

[0248] Each of the examples of FIG. 13 A through FIG. 13H includes eight total electrodes 1370. However, it should be understood that any suitable number of electrodes 1370 can be used with the devices, system, and method described herein, and the patterns and / or layouts of electrodes 1370 in each of FIG. 13A through FIG. 13H can in some cases be extrapolated and / or applied with a different number of electrodes 1370. As some existing medical devices (e.g., configured to apply stimulation therapy and / or facilitate sensing via electrodes 1370) include eight channels for electrically and / or mechanical coupling to electrodes, the examples of eight of electrodes 1370 herein can correspond to such types of devices having eight channels. The patterns and layouts of electrodes 1370 described herein with respect to eight electrodes canenable therapeutically effective stimulation and / or sensing while using existing devices having eight channels configured to connect to such electrodes. However, it should be understood that in some cases, same principles regarding the positioning of electrodes 1370 can be applied in cases of medical devices with a different number of channels and configured to electrically couple to a corresponding number of electrodes (e.g., two channels, four channels, eight channels as discussed herein, sixteen channels, thirty-two channels, or more channels).

[0249] In the example of FIG. 13A, electrodes 1370 are arranged in a rectangular-shaped configuration (e.g., such that electrodes 1370 collectively form a rectangle shape). The rectangular-shaped configuration of FIG. 13A includes two of electrodes 1370 disposed at each of four respective axial locations along expandable structure 1390 (e.g., where each axial location includes a direction along central longitudinal axis 1311). With reference to the 5 by 5 grid in FIG. 13A, four of electrodes 1370 are positioned in each of row R2 and row R3, and two of electrodes 1370 are positioned in each of column Cl, column C2, column C3, and column C4. In the example of FIG. 13A, each row that includes at least one of electrodes 1370 (e.g., row R2 and row R3) includes the same number of electrodes 1370 (e.g., four of electrodes 1370). In the example of FIG. 13A, each column that includes at least one of electrodes 1370 (e.g., column Cl, column C2, column C3, and column C4) includes the same number of electrodes 1370 (e.g., two of electrodes 1370). The rectangle-shaped configuration of electrodes 1370 can facilitate uniformity in electrical stimulation and / or sensing via electrodes 1370.

[0250] In the example of FIG. 13B, electrodes 1370 are arranged in an hourglass configuration (e.g., such that electrodes 1370 collectively form an hourglass shape). With reference to the 5 by 5 grid in FIG. 13B, three of electrodes 1370 are positioned in column Cl at row Rl, row R3, and row R5, two of electrodes 1370 are positioned in column C2 at row R2 and row R4, and three of electrodes 1370 are positioned in column C3 at row Rl, row R3, and row R5.

[0251] In the example of FIG. 13C, electrodes 1370 are arranged in a stretched hourglass configuration (e.g., stretched as compared to the example of the hourglass configuration of FIG. 13B, such that electrodes 1370 collectively form a stretched hourglass shape). With reference to the 5 by 5 grid in FIG. 13C, two of electrodes 1370 are positioned in column Cl at row Rl and row R5, two of electrodes 1370 are positioned in column C2 at row R2 and row R4, two of electrodes 1370 are positioned in column C3 at row R2 and row R4, and two of electrodes 1370 are positioned in column C4 at row Rl and row R5.

[0252] In the example of FIG. 13D, electrodes 1370 are arranged in a hollow square-shaped configuration (e.g., such that electrodes 1370 collectively form a square shape with a hollow center). The hollow square-shaped configuration of FIG. 13D includes electrodes 1370 in a 3 by3 formation with no center electrode. With reference to the 5 by 5 grid in FIG. 13D, three of electrodes 1370 are positioned in column Cl at row Rl, row R3, and row R5, two of electrodes 1370 are positioned in column C2 at row Rl and row R5, and three of electrodes 1370 are positioned in column C3 at row Rl, row R3, and row R5.

[0253] In the example of FIG. 13E, electrodes 1370 are arranged in a football-shaped configuration (e.g., such that electrodes 1370 collectively form a football shape). With reference to the 5 by 5 grid in FIG. 13E, one of electrodes 1370 is positioned in column Cl at row R3, three of electrodes 1370 are positioned in column C2 at row Rl, row R3, and row R5, three of electrodes 1370 are positioned in column C3 at row Rl, row R3, and row R5, and one of electrodes 1370 is positioned in column C4 at row R3.

[0254] In the example of FIG. 13F, electrodes 1370 are arranged in a staircase configuration (e.g., such that electrodes 1370 collectively form a staircase shape). With reference to the 5 by 5 grid in FIG. 13F, one of electrodes 1370 is positioned in column Cl at row R5, two of electrodes 1370 are positioned in column C2 at row R4 and row R5, two of electrodes 1370 are positioned in column C3 at row R3 and row R4, two of electrodes 1370 are positioned in column C4 at row R2 and row R3, and one of electrodes 1370 is positioned in column C5 at row Rl. In the example of FIG. 13F, electrodes 1370 form a descending staircase from proximal end 1390A to distal end 1390B. The staircase configuration of FIG. 13F can also be considered a spiral configuration, as electrodes 1370 at least a partial spiral around expandable structure 1390.

[0255] In the example of FIG. 13G, electrodes 1370 are arranged in a drop-shaped configuration (e.g., such that electrodes 1370 collectively form a drop shape, such as a rain drop shape that includes one pointed end and another more rounded end). With reference to the 5 by 5 grid in FIG. 13G, one of electrodes 1370 is positioned in column Cl at row R3, two of electrodes 1370 are positioned in column C2 at row R2 and row R4, three of electrodes 1370 are positioned in column C3 at row Rl, row R3, and row R5, and two of electrodes 1370 are positioned in column C4 at row R2 and row R4.

[0256] In the example of FIG. 13H, electrodes 1370 are arranged in an hourglass configuration (e.g., such that electrodes 1370 collectively form an hourglass shape, which may be an axially elongated version of the hourglass shape of FIG. 13B). With reference to the 5 by 5 grid in FIG. 13H, three of electrodes 1370 are positioned in column Cl at row Rl, row R3, and row R5, two of electrodes 1370 are positioned in column C3 at row R2 and row R4, and three of electrodes 1370 are positioned in column C5 at row Rl, row R3, and row R5. In some examples, as illustrated in the example of FIG. 13H, axially adjacent electrodes 1370 can be separate by a length greater than a length of each electrode. For example, electrodes 1370 positioned in column Cl can be separated from electrodes 1370 positioned in column C3 (e.g., in a direction centrallongitudinal axis 1311) by a length greater than a length of one of electrodes 1370. As another example, electrodes 1370 positioned in column C3 can be separated from electrodes 1370 positioned in column C5 (e.g., in a direction central longitudinal axis 1311) by a length greater than a length of one of electrodes 1370.

[0257] Each of the configurations of electrodes 1370 described in each of FIG. 13A through FIG. 13H can facilitate therapeutically effective electrical stimulation and / or sensing of nerves from an endovascular location. Where a relatively small and / or limited number of electrodes 1370 can be used (e.g., eight electrodes) due to space constraints and / or device configuration constraints, each or any of the layout configurations of electrodes 1370 described in each of FIG. 13 A through FIG. 13H can facilitate stimulation from a suitable number of axially and circumferentially spaced apart locations such as to effectively capture (e.g., for stimulation and / or sensing) a target area of a nerve that is located radially outside of a vessel in which expandable structure 1390 with 1370 is positioned.

[0258] FIG. 14 illustrates an example expandable structure 1490, which is an example of expandable structure 19 of FIG. 1 and / or expandable structure 190 of FIG. 3A and FIG. 3B. The example of FIG. 14 illustrates expandable structure 1490 in a two-dimensional view (e.g., as though the tubular body of expandable structure 1490 were cut and laid flat in a two-dimensional plane).

[0259] Expandable structure 1490 of FIG. 14 can be configured similarly to expandable structure 190 of FIG. 3 A and FIG. 3B, and / or expandable structure 490 of FIG. 4A and FIG. 4B, except as described herein. In some examples, a body portion of expandable structure 1490 extends between a tubular body proximal end 1490A and a tubular body distal end 1490B. In some examples, as shown in the example of FIG. 14, expandable structure 1490 includes a plurality of struts 1492 (which may be an example of struts 192 in the example of FIG. 3A). In some examples, as shown in the example of FIG. 14, expandable structure 1490 includes a plurality of connection elements 1464 between (e.g., located axially between) at least some of struts 1492. Connection elements 1464 may be integrally formed with struts 1492 (e.g., include the same material as struts 1492). Connection elements 1464 may be configured similar to connection elements 464 of FIG. 4A except as described herein. Expandable structure 1490 also includes a plurality of electrode attachment elements 1494, which may be examples of electrode attachment elements 194 of FIG. 3 A, electrode attachment elements 494 of FIG. 4A and FIG. 4B, or any of the other electrode attachment elements described in this disclosure. Each of electrode attachment elements 1494 can be configured to receive at least one electrode (e.g., such as one or more of electrodes 170 of FIG. 3 A, or any of the other electrodes described in this disclosure), such as to facilitate mechanical coupling of one or more electrodes to expandable structure 1490.

[0260] In the example of FIG. 14, expandable structure 1490 defines a plurality of different sections, wherein each section is represented as a column extending in the positive and negative y-axis directions according to the orthogonal x-y-z axes in the example of FIG. 14. In other words, each section of expandable structure 1490 includes a portion of expandable structure 1490 located at a particular axial location and / or spanning an axial distance (e.g., along the x-axis) and extending around a central longitudinal axis 1411 of expandable structure 1490. In some examples, expandable structure 1490 defines central longitudinal axis 1411 (e.g., such that longitudinal axis 1411 extends through a radial center of expandable structure 1490), and each section extends around longitudinal axis 1411 (e.g., in a circumferential direction around longitudinal axis 1411). For example, expandable structure 1490 defines a plurality of electrode attachment sections 1452 (shown individually as electrode attachment section 1452 A, electrode attachment section 1452B, electrode attachment section 1452C, and electrode attachment section 1452D, but collectively referred to herein as electrode attachment sections 1452). Each of electrode attachment sections 1452 can include one or more electrode attachment elements 1494 (e.g., each of which may be configured to receive one or more electrodes). In the example of FIG. 14, each of electrode attachment section 1452 A, electrode attachment section 1452B, electrode attachment section 1452C, and electrode attachment section 1452D includes at least three electrode attachment elements 1494. However, each of electrode attachment sections 1452 can include any suitable number of electrode attachment elements 1494 (e.g., one, two, three, four, five, six, ten, or more electrode attachment elements 1494, or any suitable number therebetween).

[0261] In some examples, expandable structure 1490 defines one or more additional sections (e.g., other than electrode attachment sections 1452). In some examples, expandable structure 1490 defines a proximal-most section 1456 (e.g., which is located proximal to all electrode attachment sections 1452). In some examples, expandable structure 1490 defines one or more intermediate sections 1458 (e.g., illustrated as three intermediate sections 1458 in the example of FIG. 14). In some examples, the intermediate sections 1458 do not include any electrode attachment elements 1494 and are positioned between proximal-most section 1456 and a proximal-most one of electrode attachment sections 1452 (e.g., electrode attachment section 1452D in the example of FIG. 14).

[0262] In some examples, as shown in the example of FIG. 14, each of electrode attachment sections 1452, proximal-most section 1456, and intermediate sections 1458 includes a subset of struts 1492 that define (e.g., form) a respective plurality of proximal crowns 1493 and a plurality of distal crowns 1495 (only a portion of proximal crowns 1493 and plurality of distal crowns 1495 labeled in FIG. 14). Each of proximal crowns 1493 and distal crowns 1495 of each ofelectrode attachment sections 1452, proximal-most section 1456, and intermediate sections 1458 can include a vertex where two or more of struts 1492 intersect to form a respective proximal apex or distal apex. In some examples, one or more of each of electrode attachment sections 1452 include at least ten distal crowns 1495. In some examples, one or more of each of electrode attachment sections 1452 include at least ten proximal crowns 1495. In the example of FIG. 14, proximal crowns 1493 and distal crowns 1495 of at least some adjacent sections (e.g., proximal- most section 1456 and adjacent intermediate sections 1458) are directly connected (e.g., without any intervening connection elements 1464).

[0263] As shown in the example of FIG. 14, expandable structure 1490 defines a plurality of connection sections 1462 (e.g., shown individually as connection section 1462 A, connection section 1462B, and connection section 1462C, collectively referred to herein as connection sections 1462). In some examples, connection sections 1462 are interspersed between electrode attachment section 1452 (e.g., and not axially interspersed between either of intermediate sections 1458, and / or proximal-most section 1456). In other examples, examples, each of connection sections 1462 are axially interspersed between at least two of electrode attachment sections 1452, intermediate sections 1458, and / or proximal-most section 1456 such that connection elements 1464 of each of connection sections 1462 are configured to mechanically couple axially adjacent ones of electrode attachment sections 1452, intermediate sections 1458, and / or proximal-most section 1456. As shown in the example of FIG. 14, connection sections 1462 do not have any electrodes attached to any of connection sections 1462.

[0264] In the example of FIG. 14, expandable structure 1490 includes a radiopaque distal extension 1498, which may be an example of radiopaque distal extension 198 of FIG. 3A and FIG. 3B, radiopaque distal extension 498 of FIG. 4 A, or any of the other radiopaque distal extension described in this disclosure. In some examples, radiopaque distal extension 1498 is mechanically coupled to and extends from one of struts 1492 of a distal-most electrode attachment section 1452A. In some examples, radiopaque distal extension 1498 is mechanically coupled to one of distal crowns 1495 of electrode attachment section 1452A. In some examples, at least a portion of radiopaque distal extension 1498 includes a radiopaque or radiographic material that is visible via a suitable medical imaging modality (e.g., fluoroscopy). In some examples, a distal-most portion of radiopaque distal extension 1498 includes the radiopaque or radiographic material. As discussed previously, in some examples, radiopaque distal extension 1498 is configured to indicate a radial direction faced by electrodes that are mechanically coupled to expandable structure 1490 (e.g., via electrode attachment elements 1494).

[0265] The example of expandable structure 1490 of FIG. 14 is an example of an expandable structure in which all respective proximal crowns 1493 and all respective distal crowns 1495 aremechanically coupled between adjacent sections (e.g., between adjacent sections of electrode attachment sections 1452, intermediate sections 1458, and / or proximal-most section 1456). Such a configuration is otherwise referred to herein as a “closed-cell” configuration. In other examples herein, less than all respective proximal crowns and respective distal crowns are mechanically coupled between adjacent sections, which can otherwise be referred to herein as a “open-cell” configuration. Further, in some examples herein, an expandable structure includes some adjacent sections with all respective proximal crowns and respective distal crowns connected while other sections include less than all respective proximal crowns and respective distal crowns connected, which can otherwise be referred to herein as a “hybrid-cell” configuration.

[0266] In some examples, as illustrated in the example of FIG. 14, expandable structure 1490 defines a tapered profile. In some examples, expandable structure 1490 tapers in a proximal direction (e.g., tapers between a larger cross-sectional dimension to a smaller cross section in a proximal direction, such that proximal-most section 1456 defines a smaller cross-sectional dimension, or diameter, than other sections of expandable structure 1490). In some examples, proximal-most section 1456 and one or more of intermediate sections 1468 taper to a smaller cross-sectional dimension (e.g., diameter). This tapering profile of expandable structure 1490 can enable expandable structure 1490 to be more easily re-sheathed (e.g., as compared to expandable structures that not taper). In some examples, expandable structure 1490 tapers such that proximal-most section 1456 defines less proximal crowns 1493 as compared to other sections (e.g., as compared to an adjacent intermediate section 1458 and some or all of electrode attachment sections 1452). In some examples, proximal-most section 1456 defines a single proximal crown 1493.

[0267] In some examples, adjacent struts 1492 of proximal-most section 1456 form an angle R2. In some examples, angle R2 is sufficiently small as to enable easier re-sheathing of expandable structure 1490. In some examples, angle R2 is less than or equal to ninety degrees.

[0268] FIG. 15 is a flow diagram illustrating an example technique for using a medical device system according to the techniques of this disclosure, which may include placing a medical lead adjacent a target location in vasculature of a patient. The technique of FIG. 15 is described with respect to therapy system 10 of FIG. 1, as well as endovascular therapy system 100 of FIG. 3A and FIG. 3B (which is an example of therapy system 10 of FIG. 1), but may be used with any of the device, systems, and / or elements of systems described in this disclosure.

[0269] In the example of FIG. 15, the technique includes introducing an endovascular device (e.g., endovascular device 16 and / or medical lead 160) into vasculature of patient 12 (1500). For example, a clinician may introduce at least distal portion 150 medical lead 160 through an access point in patient 12 including a femoral artery access point or radial artery access point. In someexamples, one or more of an introducer sheath, a guide catheter, and / or a guidewire is used to facilitate introduction of medical lead 160 into patient 12.

[0270] In the example of FIG. 15, the technique further includes advancing medical lead 160 through the vasculature of the patient until electrodes 170 are adjacent a target location in the vasculature of patient 12 (1502). In some examples, a clinician advances medical lead 160 through vasculature of patient 12 until electrodes 170 are located within jugular vein 13 and positioned adjacent vagus nerve 21. In other examples, a clinician advances medical lead 160 through vasculature of patient 12 until electrodes 170 are located within a cranial blood vessel proximate one or more target brain structures. Once electrodes 170 are adjacent the target location (e.g., vagus nerve 21, other nerve, or one or more brain structures), the clinician initiates (e.g., via programmer 20, or another suitable device) electrical stimulation therapy and / or sensing of one or more patient parameters by medical device 14 via electrodes 170. In some examples, medical lead 160 including electrodes 170 can be advanced to the target location with the aid of delivery catheter 142.

[0271] In some examples, expandable structure 190, which can be at a distal portion of medical lead 160, is configured to transform from a relatively low-profile delivery configuration to a deployed configuration in a blood vessel of a patient (e.g., within jugular vein 13 of patient 12). In some examples, expandable structure 190 remains in the delivery configuration during advancement of medical lead 160 through the vasculature.

[0272] In some examples, a clinician causes expandable structure 190 to transform to the deployed (e.g., expanded) configuration once electrodes 170 are adjacent the target site (e.g., by advancing expandable structure 190 distally of delivery catheter 142). In the deployed configuration of expandable structure 190, one or more of electrodes 170 can be positioned into apposition with the vessel wall (e.g., the vessel wall of jugular vein 13).

[0273] In some examples, one or more elements of therapy system 100 is configured to facilitate positioning of electrodes 170 at the target site (e.g., via radiographic and / or radiopaque portions that indicate a positioning of electrodes 170). In some examples, a radiographic and / or radiopaque portion of therapy system 100 is aligned with one or more of electrodes 170 (and / or circumferentially aligned an array of electrodes formed from a group of electrodes 170) to indicate a direction (e.g., a radial direction outward from central longitudinal axis 111) faced by electrodes 170. In some examples, therapy system 100 (e.g., one or more components of therapy system 100) includes a radiographic or radiopaque marker that is circumferentially aligned with one or more of electrodes 170 and / or an electrode array formed by electrodes 170. In some examples, one or more of medical lead 160, and / or expandable structure 190 includes a radiographic or radiopaque material circumferentially aligned with electrodes 170 and configuredto indicate a radial direction (e.g., a radial direction outwards from central longitudinal axis 111) faced by electrodes 170 (e.g., when expandable structure 190 is in the deployed configuration). As discussed with respect to FIG. 3 A, distal radiopaque extension 198 is circumferentially aligned with array of electrodes 170 and configured to indicate a radial direction faced by electrodes 170, e.g., even when expandable structure is in the delivery (e.g., compressed) configuration and / or when expandable structure is initially deployed (e.g., when only a distal portion of expandable structure is advanced distally of delivery catheter 142).

[0274] The techniques described in this disclosure, including those attributed to medical device 14, programmer 20, or various constituent components, may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the techniques may be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components, embodied in programmers, such as clinician or patient programmers, medical devices, or other devices. Processing circuitry, control circuitry, and sensing circuitry, as well as other processors and controllers described herein, may be implemented at least in part as, or include, one or more executable applications, application modules, libraries, classes, methods, objects, routines, subroutines, firmware, and / or embedded code, for example. In addition, analog circuits, components, and circuit elements may be employed to construct one, some or all of the processing circuitry 30, instead of or in addition to the partially or wholly digital hardware and / or software described herein. Accordingly, analog or digital hardware may be employed, or a combination of the two.

[0275] In one or more examples, the functions described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on, as one or more instructions or code, a computer- readable medium and executed by a hardware-based processing unit. The computer-readable medium may be an article of manufacture including a non-transitory computer-readable storage medium encoded with instructions. Instructions embedded or encoded in an article of manufacture including a non-transitory computer-readable storage medium encoded, may cause one or more programmable processors, or other processors, to implement one or more of the techniques described herein, such as when instructions included or encoded in the non-transitory computer-readable storage medium are executed by the one or more processors. Example non- transitory computer-readable storage media may include RAM, ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), flash memory, a hard disk, a compact disc ROM (CD-ROM), a floppy disk, acassette, magnetic media, optical media, or any other computer readable storage devices or tangible computer readable media.

[0276] In some examples, a computer-readable storage medium comprises non-transitory medium. The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, a non-transitory storage medium stores data that can, over time, change (e.g., in RAM or cache).

[0277] The functionality described herein may be provided within dedicated hardware and / or software modules. Depiction of different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be realized by separate hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0278] This disclosure includes the following non-limiting examples.

[0279] Example 1 A: An endovascular medical device includes an expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements, the array of electrodes generally facing in a radial direction outward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, and wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expandable structure is expanded in a blood vessel.

[0280] Example 2 A: The endovascular medical device of example 1 A, wherein the radiopaque distal extension extends from about 2.0 mm to about 10.0 mm distally of the distal end of the tubular body of the expandable structure.

[0281] Example 3A: The endovascular medical device of any of examples 1 A and 2A, wherein each respective electrode attachment element of the plurality of electrode attachment elements includes a projection, each projection branching off from a strut of the plurality of connected struts, and wherein each electrode of the array of electrodes is disposed on a respective projection of the plurality of electrode attachment elements.

[0282] Example 4A: The endovascular medical device of any of examples 1 A through 3A, wherein at least some axially adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm between respective axial centers of the respective axially adjacent electrodes.

[0283] Example 5 A: The endovascular medical device of any of examples 1 A through 4 A, wherein at least some circumferentially adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm around the expandable structure.

[0284] Example 6 A: The endovascular medical device of any of examples 1 A through 5 A, wherein for each respective electrode coupled to the expandable structure via a respective electrode attachment element: a first minimum distance separates the respective electrode and a respective nearest strut, a second minimum distance separates a distal portion of the respective electrode attachment element and the respective nearest strut, and the first minimum distance is greater than the second minimum distance.

[0285] Example 7 A: The endovascular medical device of any of examples 1 A through 6 A, wherein at least a portion of each respective electrode attachment element of the plurality of electrode attachment elements is configured to flex away from a respective nearest strut to facilitate coupling of the respective electrode of the array of electrodes to the respective electrode attachment element.

[0286] Example 8A: The endovascular medical device of example 7A, wherein the portion of each electrode attachment element configured to flex away from the respective nearest strut defines a plurality of relief cuts.

[0287] Example 9 A: The endovascular medical device of any of examples 1 A through 8 A, further includes the first insulative portion is positioned radially outside of the respective electrode attachment element and radially inside of the respective electrode, and the second insulative portion is positioned radially outside of the respective electrode attachment element and adjacent at least one end of the respective electrode.

[0288] Example 10 A: The endovascular medical device of any of examples 1 A through 9 A, wherein the expandable structure includes one or more radiopaque proximal extensions extending proximally of the proximal end of the tubular body of the expandable structure, the one or more radiopaque proximal extensions circumferentially offset from the array of electrodes.

[0289] Example 11 A: The endovascular medical device of any of examples 1 A through 10 A, wherein the array of electrodes includes at least four groups of electrodes axially spaced apart along the expandable structure.

[0290] Example 12 A: The endovascular medical device of any of examples 1 A through 11 A, wherein the array of electrodes includes at least two groups of electrodes circumferentially spaced apart along the expandable structure.

[0291] Example 13A: The endovascular medical device of any of examples 1 A through 12A, wherein the expandable structure is configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed configuration to position the array of electrodes to deliver electrical stimulation to tissue or sense a patient parameter from a location within a blood vessel.

[0292] Example 14A: The endovascular medical device of example 13A, wherein in the deployed configuration, at least a proximal portion of the expandable structure is configured to anchor the expandable structure within the blood vessel.

[0293] Example 15 A: The endovascular medical device of example 14A, wherein in the deployed configuration: the proximal portion of the expandable structure defines a first maximum dimension, a distal portion of the expandable structure including the array of electrodes defines a second maximum dimension, and the first maximum dimension is greater than the second maximum dimension.

[0294] Example 16 A: A method of using a medical device system includes introducing a medical device into vasculature of a patient, the medical device including: an expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements, the array of electrodes generally facing in a radial direction outward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, and wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expandable structure is expanded in a blood vessel; and advancing the medical device until the array of electrodes are at or near a target location in the vasculature of the patient.

[0295] Example 17 A: The method of example 16 A, wherein the radiopaque distal extension extends from about 2.0 mm to about 10.0 mm distally of the distal end of the tubular body of the expandable structure.

[0296] Example 18 A: The method of any of examples 16A and 17 A, wherein the plurality of electrode attachment elements includes a plurality of projections, each projection of the plurality of projections branching off from a strut of the plurality of connected struts, and wherein eachelectrode of the array of electrodes is disposed on a respective projection of the plurality of projections.

[0297] Example 19 A: The method of any of examples 16A through 18 A, wherein at least some axially adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm between respective axial centers of the respective axially adjacent electrodes.

[0298] Example 20 A: The method of any of examples 16A through 19 A, wherein at least some circumferentially adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm around the expandable structure.

[0299] Example 21 A: The method of any of examples 16A through 20 A, wherein for each respective electrode coupled to the expandable structure via a respective electrode attachment element: a first minimum distance separates the respective electrode and a respective nearest strut, a second minimum distance separates a distal portion of the respective electrode attachment element and the respective nearest strut, and the first minimum distance is greater than the second minimum distance.

[0300] Example 22 A: The method of any of examples 16A through 21 A, wherein at least a portion of each respective electrode attachment element of the plurality of electrode attachment elements is configured to flex away from a respective nearest strut to facilitate coupling of the respective electrode of the array of electrodes to the respective electrode attachment element.

[0301] Example 23 A: The method of example 22A, wherein the portion of each electrode attachment configured to flex away from the respective nearest strut includes a plurality of relief cuts.

[0302] Example 24A: The method of any of examples 16A through 23 A, wherein the medical device further includes a first insulative portion and a second insulative portion, wherein for each respective electrode attachment element of the plurality of electrode attachment elements coupled to a respective electrode of the array of electrodes: the first insulative portion is positioned radially outside of the respective electrode attachment element and radially inside of the respective electrode, and the second insulative portion is positioned radially outside of the respective electrode attachment element and adjacent at least one end of the respective electrode.

[0303] Example 25 A: The method of any of examples 16A through 24 A, wherein the expandable structure includes one or more radiopaque proximal extensions extending proximally of the proximal end of the tubular body of the expandable structure, the one or more radiopaque proximal extensions circumferentially offset from the array of electrodes.

[0304] Example 26 A: The method of any of examples 16A through 25 A, wherein the array of electrodes includes at least 4 groups of electrodes axially spaced apart along the expandable structure.

[0305] Example 27 A: The method of any of examples 16A through 26 A, wherein the array of electrodes includes at least 2 groups of electrodes circumferentially spaced apart along the expandable structure.

[0306] Example 28 A: The method of any of examples 16A through 27 A, wherein the expandable structure is configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed configuration to position the array of electrodes to deliver electrical stimulation to tissue or sense a patient parameter from a location within a blood vessel.

[0307] Example 29A: The method of example 28A, wherein in the deployed configuration, at least a proximal portion of the expandable structure is configured to anchor the expandable structure within the blood vessel.

[0308] Example 30A: The method of example 29A, wherein in the deployed configuration: the proximal portion of the expandable structure defines a first maximum dimension, a distal portion of the expandable structure including the array of electrodes defines a second maximum dimension, and the first maximum dimension is greater than the second maximum dimension.

[0309] Example 31 A: An endovascular medical device includes an expandable structure configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed configuration within a blood vessel, the expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements such that when the expandable structure is in the deployed configuration, adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm, the array of electrodes generally facing in a radial direction outward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body by about 2.0 mm to about 10.0 mm, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expa...

Claims

WHAT IS CLAIMED IS:

1. An endovascular medical device comprising: an expandable structure including: a plurality of connected struts defining a tubular body, the tubular body extending between a proximal end and a distal end, and a plurality of electrode attachment elements, each electrode attachment element connected to at least one respective strut of the plurality of connected struts; and an array of electrodes, each respective electrode of the array of electrodes coupled to the expandable structure via a respective electrode attachment element of the plurality of electrode attachment elements, the array of electrodes generally facing in a radial direction outward from the expandable structure, wherein the expandable structure includes a radiopaque distal extension extending distally of the distal end of the tubular body, the radiopaque distal extension generally circumferentially aligned with the array of electrodes, and wherein the radiopaque distal extension is configured to indicate the radial direction of the electrodes when the expandable structure is expanded in a blood vessel.

2. The endovascular medical device of claim 1, wherein the radiopaque distal extension extends from about 2.0 mm to about 10.0 mm distally of the distal end of the tubular body of the expandable structure.

3. The endovascular medical device of any of claims 1 and 2, wherein each respective electrode attachment element of the plurality of electrode attachment elements includes a projection, each projection branching off from a strut of the plurality of connected struts, and wherein each electrode of the array of electrodes is disposed on a respective projection of the plurality of electrode attachment elements.

4. The endovascular medical device of any of claims 1 through 3, wherein at least some axially adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm between respective axial centers of the respective axially adjacent electrodes.

5. The endovascular medical device of any of claims 1 through 4, wherein at least some circumferentially adjacent electrodes are spaced apart by about 5.0 mm to about 7.0 mm around the expandable structure.

6. The endovascular medical device of any of claims 1 through 5, wherein for each respective electrode coupled to the expandable structure via a respective electrode attachment element: a first minimum distance separates the respective electrode and a respective nearest strut, a second minimum distance separates a distal portion of the respective electrode attachment element and the respective nearest strut, and the first minimum distance is greater than the second minimum distance.

7. The endovascular medical device of any of claims 1 through 6, wherein at least a portion of each respective electrode attachment element of the plurality of electrode attachment elements is configured to flex away from a respective nearest strut to facilitate coupling of the respective electrode of the array of electrodes to the respective electrode attachment element.

8. The endovascular medical device of claim 7, wherein the portion of each electrode attachment element configured to flex away from the respective nearest strut defines a plurality of relief cuts.

9. The endovascular medical device of any of claims 1 through 8, further comprising a first insulative portion and a second insulative portion, wherein for each respective electrode attachment element of the plurality of electrode attachment elements coupled to a respective electrode of the array of electrodes: the first insulative portion is positioned radially outside of the respective electrode attachment element and radially inside of the respective electrode, and the second insulative portion is positioned radially outside of the respective electrode attachment element and adjacent at least one end of the respective electrode.

10. The endovascular medical device of any of claims 1 through 9, wherein the expandable structure includes one or more radiopaque proximal extensions extending proximally of the proximal end of the tubular body of the expandable structure, the one or more radiopaque proximal extensions circumferentially offset from the array of electrodes.

11. The endovascular medical device of any of claims 1 through 10, wherein the array of electrodes includes at least four groups of electrodes axially spaced apart along the expandable structure.

12. The endovascular medical device of any of claims 1 through 11, wherein the array of electrodes includes at least two groups of electrodes circumferentially spaced apart along the expandable structure.

13. The endovascular medical device of any of claims 1 through 12, wherein the expandable structure is configured to expand radially outwards from a relatively low-profile delivery configuration to a deployed configuration to position the array of electrodes to deliver electrical stimulation to tissue or sense a patient parameter from a location within a blood vessel.

14. The endovascular medical device of claim 13, wherein in the deployed configuration, at least a proximal portion of the expandable structure is configured to anchor the expandable structure within the blood vessel.

15. The endovascular medical device of claim 14, wherein in the deployed configuration: the proximal portion of the expandable structure defines a first maximum dimension, a distal portion of the expandable structure including the array of electrodes defines a second maximum dimension, and the first maximum dimension is greater than the second maximum dimension.

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