Implantable medical device

Abstract

An implantable medical device includes a power element, stimulation circuitry and / or a sensor to sense physiologic information of a patient, and a housing. The housing encloses the power element and the stimulation circuitry and / or the sensor. The housing is configured to be implanted within a head-and-neck region of the patient.

Description

Background

[0001] A significant portion of the population suffers from various forms of sleep-related issues, some of which may involve sleep disordered breathing (SDB) and / or other conditions. In some patients, external breathing therapy devices and / or mere surgical interventions may fail to treat the sleep disordered breathing behavior. Brief Description of the Drawings

[0002] FIG. 1A is a diagram schematically representing an example method and / or example device in relation to a target tissue.

[0003] FIG. 1B is a diagram including a front view schematically representing a patient’s body including example implantable components and example external elements of example methods and / or example devices.

[0004] FIG. 1C is a block diagram of a control portion.

[0005] FIGS. 1D-1DD are diagrams schematically representing example implantable medical devices (IMDs) implanted at various locations in a head-and-neck region.

[0006] FIG. 1E is a diagram schematically representing example implant and / or therapy locations for various nerves, including an infrahyoid muscle (IHM)-innervating nerves.

[0007] FIGS. 2A-2D are diagrams schematically representing example IMDs including a wireless receiver.

[0008] FIG. 3A is a diagram schematically representing an example antenna including three orthogonal coils.

[0009] FIG. 3B is a diagram schematically representing an example trace antenna.

[0010] FIG. 3C is a diagram schematically representing an example chip antenna. 2

[0011] FIGS. 4A and 4B are diagrams schematically representing an example IMD including a two-part housing.

[0012] FIGS. 5A and 5B are diagrams schematically representing an example IMD including a two-part housing including metal bands.

[0013] FIGS. 6A and 6B are diagrams schematically representing example IMDs including overmolded housings.

[0014] FIG. 7A is a diagram schematically representing an example IMD including an antenna arranged on a lead of the IMD.

[0015] FIG. 7B is a diagram schematically representing an example IMD including an antenna within an end cap of the housing.

[0016] FIG. 70 is a diagram schematically representing an example IMD including a housing including a window and an antenna adjacent to the window.

[0017] FIG. 7D is a diagram schematically representing an example IMD including an acoustic sensor.

[0018] FIG. 7E is a diagram schematically representing an example IMD including an acoustic sensor adjacent to a window.

[0019] FIG. 8 is a diagram schematically representing additional details of the IMD of FIG. 7C.

[0020] FIG. 9 is a diagram schematically representing an example solid-state battery.

[0021] FIG. 10 is a diagram schematically representing an example silicon interposer for an IMD.

[0022] FIGS. 11A-11D are diagrams schematically representing example IMDs including at least one silicon interposer.

[0023] FIGS. 12A-12E are various views schematically representing an example IMD.

[0024] FIGS. 12F and 12G are partial sectional views schematically representing an example implantation of an IMD.

[0025] FIG. 12H is a top view of a face portion of an example housing of an IMD which include electrodes exposed on a surface of the face portion of the housing. 3

[0026] FIG. 121 is a sectional side view illustrating at least the exposed electrodes and face portion in FIG. 12H.

[0027] FIGS. 13A-13E are various views schematically representing an example IMD.

[0028] FIGS. 13F and 13G are partial sectional views schematically representing an example implantation of an IMD.

[0029] FIGS. 14A-14E are various views schematically representing an example IMD.

[0030] FIGS. 14F-14H are partial sectional views schematically representing an example implantation of an IMD.

[0031] FIGS. 15A-15E are various views schematically representing an example IMD.

[0032] FIGS. 15F and 15G are partial sectional views schematically representing an example implantation of an IMD.

[0033] FIGS. 16A-16E are various views schematically representing an example IMD.

[0034] FIGS. 17A-17E are various views schematically representing an example IMD.

[0035] FIGS. 18A-18E are various views schematically representing an example IMD.

[0036] FIGS. 19A-19E are various views schematically representing an example IMD.

[0037] FIGS 20A-20F are various views schematically representing an example IMD.

[0038] FIGS. 20G and 20H are top views schematically representing additional examples of the IMD of FIGS. 20A-20F.

[0039] FIG. 21 is a top view schematically representing an additional example of the IMD of FIGS. 20A-20F.

[0040] FIGS. 22A and 22B are diagrams schematically representing an example tool for implanting an IMD in a patient. 4

[0041] FIG. 23A is a diagram including a side view schematically representing a stimulation lead comprising an example stimulation portion including an anchor structure.

[0042] FIGS. 23B and 23C are each a sectional view schematically representing an example implementation of the example stimulation portion of FIG. 23A.

[0043] FIG. 23D is a diagram including a side view schematically representing an example stimulation portion and / or sensor portion including an anchor structure.

[0044] FIGS. 23E and 23F are each a diagram including a side view schematically representing an example anchor element.

[0045] FIGS. 24A-24C are each a diagram including a side view schematically representing an example portion of a stimulation lead and / or sensor lead including an anchor structure.

[0046] FIG. 24D is a sectional view schematically representing an example stimulation portion and / or sensor portion including an anchor structure.

[0047] FIGS. 24E and 24F are each a diagram schematically representing an example stimulation lead and / or sensor lead including anchor portions.

[0048] FIGS. 25A and 25B are diagrams including a top view and a side view, respectively, schematically representing example anchor structures.

[0049] FIGS. 25C-25E are each a side view schematically representing a portion of an example stimulation lead and / or sensor lead including tines as a fixation structure.

[0050] FIGS. 25F-25H are each a diagram including a side plan view schematically representing an example stimulation lead and / or sensor lead including example tines as part of a fixation structure.

[0051] FIGS. 26A-26C are each a diagram including a sectional view of an example paddle-style stimulation portion including example anchor portions.

[0052] FIGS. 27A, 27D and FIGS. 27B-27C are diagrams including a top plan view and bottom plan view (respectively) of an example paddle-style stimulation portion including example anchor portions.

[0053] FIG. 27E is a diagram including a side plan view of an example connector portion including a helical-shaped anchor structure. 5

[0054] FIG. 28 is a flow diagram schematically representing an example method for applying electrical stimulation to a patient.

[0055] FIG. 29 is a diagram schematically representing an example IMD within a patient.

[0056] FIGS. 30A-30C are diagrams, including side views, illustrating example IMDs for sensing and / or stimulation.

[0057] FIG. 31A is a block diagram schematically representing an example sensing portion of an example device and / or used as part of an example method.

[0058] FIG. 31B is a block diagram schematically representing an example stimulation portion.

[0059] FIGS. 32A and 32B are block diagrams schematically representing example control portions.

[0060] FIG. 32C is a block diagram schematically representing an example user interface.

[0061] FIG. 33 is a block diagram schematically representing example communication arrangements between an IMD and external devices. Detailed Description

[0062] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized, and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise.

[0063] At least some examples of the present disclosure are directed to devices for diagnosis, therapy, and / or other care of medical conditions. At least some examples may comprise implantable devices and / or methods comprising use of implantable devices. However, in some examples, the methods and / or devices may comprise at least some external components. In some examples, a therapeutic medical device may comprise a combination of implantable components and external components.

[0064] At least some of the example devices and / or example methods may relate to sleep disordered breathing (SDB) care, which may comprise monitoring, diagnosis, evaluation, and / or treatment, which may comprise stimulation in some examples. At least some examples include implantable medical devices (IMDs) including housings having shapes and features configured for fixation to specific tissues within a patient, configured for ease of access and delivery, and / or configured for effective therapy (e.g., stimulation). At least some example implantable medical devices include structures and configurations within a housing of the IMDs which are conducive to reducing a size of the IMDs and / or to implementing the abovementioned sizes and / or shapes facilitating fixation. At least some example implantable medical devices include structures and configurations regarding external surfaces of a housing of the IMDs which are conducive to delivery and / or securely fixating the housing relative to anchoring tissues. Among other target tissues for stimulation and / or sensing, at least some target tissues comprise tissues of the head and / or neck regions which include nerves, muscles, and / or other tissues (e.g., tendons, bones, cartilage, etc.) related to treating sleep disordered breathing such as, but not limited to, obstructive sleep apnea. These target tissues may directly or indirectly relate to promoting upper airway patency. Other target tissues also may include those tissues relating to treating pelvic disorders such as (but not limited to) treating urinary and / or fecal incontinence.

[0065] These examples, and additional examples, are further described in association with at least FIGS. 1A-33.

[0066] FIG. 1A is a block diagram schematically representing an example arrangement 50 (an example device and / or example method) an implantable medical device (IMD) 52 in operable relation to target tissue(s) 60. In some examples, the IMD 52 may comprise a sensing element 54, a stimulation element 7 56, and / or other element 58 (or function) such that the IMD 52 may be in sensing relation, stimulating relation, and / or other relation with the target tissue(s) 60.

[0067] FIG. 1B is a block diagram schematically representing a patient’s body 100, including example target portions 110-134 at which at least some example sensing element(s), stimulation element(s), and / or other elements may be employed to implement at least some examples of the present disclosure.

[0068] As shown in FIG. 1B, patient’s body 100 comprises a head-and-neck portion 110, including head 112 and neck 114. Head-and-neck portion 110 comprises cranial tissue, nerves, etc., and upper airway 116 (e.g., nerves, muscles, tissues), etc. which primarily extends through and within the neck 114. As further shown in FIG. 1B, the patient’s body 100 comprises a torso 120, which comprises various organs, muscles, nerves, other tissues, such as but not limited to those in pectoral region 122 (e.g., lungs 126, cardiac 127), abdomen 124, and / or pelvic region 129 (e.g., urinary / bladder, anal, reproductive, etc.). As further shown in FIG. 1B, the patient’s body 100 comprises limbs 130, such as arms 132 and legs 134.

[0069] It will be understood that various sensing elements (and / or stimulation elements) as described throughout the various examples of the present disclosure may be deployed within the various regions of the patient’s body 100 to sense and / or otherwise diagnose, monitor, treat various physiologic conditions such as, but not limited to those examples described below in association with FIGS. 2A-33. In some such examples, a stimulation element 117 may be located in or near the upper airway 116 for treating sleep disordered breathing (and / or near other nerves / muscles for treating other conditions) and / or a sensing element 128 may be located anywhere within the neck 114, head 112, and / or torso 120 (or other body regions) to sense physiologic information for providing patient care (e.g., SDB, other) and / or for other purposes.

[0070] In some examples, at least a portion of the stimulation element 117 may comprise part of an implantable component / device, such as an implantable pulse generator (IPG) whether full sized or sized as a microstimulator. The implantable components (e.g., IPG, other) may comprise a stimulation / control circuit, a power 8 supply (e.g., non-rechargeable, rechargeable), communication elements, and / or other components. In some examples, the stimulation element 117 also may comprise a stimulation electrode and / or stimulation lead connected to the implantable pulse generator.

[0071] Further details regarding the location, structure, operation, and / or use of the sensing element 128, external element(s) 150, and / or stimulation element 117 are described below in association with at least FIGS. 1C-33.

[0072] In some examples, at least a portion of the stimulation element 117 may comprise part of an external component / device such as, but not limited to, the external component comprising a pulse generator (e.g., stimulation / control circuitry), power supply (e.g., rechargeable, non-rechargeable), and / or other components. In some examples, a portion of the stimulation element 117 may be implantable and a portion of the stimulation element 117 may be external to the patient.

[0073] Accordingly, as further shown in FIG. 1B, the various sensing element(s) 128 and / or stimulation element(s) 117 implanted in the patient’s body may be in wireless communication (e.g., connection 137) with at least one external element 150.

[0074] As further shown in FIG. 1B, in some examples, the external element(s) 150 may be implemented via a wide variety of formats such as, but not limited to, at least one of the formats 151 including a patient support 152 (e.g., bed, chair, sleep mat, other), wearable elements 154 (e.g., finger, wrist, head, neck, shirt), noncontact elements 156 (e.g., watch, camera, mobile device, other), and / or other elements 158.

[0075] As further shown in FIG. 1B, in some examples, the external element(s) 150 may comprise one or more different modalities 170 such as (but not limited to) a sensing portion 171, stimulation portion 172, power portion 174, communication portion 176, and / or other portion 178. The different portions 171, 172, 174, 176, 178 may be combined into a single physical structure (e.g., package, arrangement, assembly), may be implemented in multiple different physical structures, and / or with 9 just some of the different portions 171, 172, 174, 176, 178 combined together in a single physical structure.

[0076] Among other such details, in some examples the external sensing portion 171 and / or implanted sensing element 128 may comprise at least some of substantially the same features and attributes of at least sensing portion 3000, as further described below in FIG. 31 A.

[0077] In some examples, the external stimulation portion 172 and / or implantable portions of stimulation element 117 may comprise at least some of substantially the same features and attributes of at least the stimulation arrangements, as further described below in association with at least FIGS. 1D-33 and / or other examples throughout the present disclosure.

[0078] In some examples, the external power portion 174 and / or power components associated with stimulation element 117 (e.g., implantable portions) may comprise at least some of substantially the same features and attributes of at least the stimulation arrangements, as further described throughout the examples of the present disclosure. In some such examples, the respective power portion, components, etc. may comprise a rechargeable power element (e.g., supply, battery, circuitry elements) and / or non-rechargeable power elements (e.g., battery). In some examples, the external power portion 174 may comprise a power source by which a power component of the stimulation element 117 (e.g., implantable portions) may be recharged.

[0079] In some examples, the wireless communication portion 176 (e.g., connection / link at 137) may be implemented via various forms of radiofrequency communication and / or other forms of wireless communication, such as (but not limited to) magnetic induction telemetry, Bluetooth (BT), Bluetooth Low Energy (BLE), near infrared (NIF), near-field protocols, Wi-Fi, Ultra-Wideband (UWB), ultrasonic waves, and / or other short range or long range wireless communication protocols suitable for use in communicating between implanted components and external components in a medical device environment.

[0080] Examples are not so limited as expressed by other portion 178 via which other aspects of implementing medical care may be embodied in external element(s) 150 to relate to the various implanted and / or external components described above.

[0081] FIG. 1C schematically represents a control portion 190, which may comprise at least some of substantially the same features and attributes as the control portion 3500 in FIG. 32A. The control portion 190 may be used to implement at least some of the various example devices and / or example methods of the present disclosure as described herein. In some examples, the control portion 190 may form part of, and / or be in communication with, the sensing element 128 and / or the stimulation element 117 in FIG. 1B, external element(s) 150, and / or other medical device (or portions thereof), as further described later.

[0082] FIG. 1D is a diagram schematically representing example locations for implanting devices for sensing and / or applying stimulation, as well as example anchoring tissue(s) for each example implant location. The devices represented in FIG. 1D may comprise an example implementation of, and / or include, at least some of substantially the same features of any device of FIGS. 1A-1C and 1DD-33.

[0083] More specifically, FIG. 1D is a diagram including a front view schematically representing deployment 200 of example electrode arrangements 21 OR, 210L, 213R, 213L, 214R, 214L, 216R, 216L deployed for sensing from and / or stimulating a plurality of target tissues. In some examples, each of the respective electrode arrangements 210R, 210L, 213R, 213L, 214R, 214L, 216R, 216L may be implanted within each of the respective locations A, B, C, D, E, F, G, H of the patient which are located respectively on right and left sides 212R, 212L in the head-and-neck 205 region of the patient 215, as shown with respect to the sagittal midline 217.

[0084] These electrode arrangements may be supported on a lead extending from a housing of an implantable medical device (IMD), or may be exposed on an exterior surface of a housing of an IMD. A housing of an IMD (which may provide for sensing, stimulation, and / or other functions) may be chronically implanted in a pectoral region of the patient and the electrode arrangements 21 OR, 210L, 213R, 213L, 214R, 214L, 216R, 216L may be chronically implanted in a head-and-neck region 205 of the patient. However, in some examples, the housing of the IMD may be formed on a smaller scale and / or different shape to be amenable for implantation in the head-and-neck region 205 instead of a pectoral region. Accordingly, in some such examples, the housing of the IMD and associated electrode arrangements may be implemented on a scale in which both the housing and electrode arrangements (e.g., including a lead in some examples), such that the entire IMD, may be implanted at or near the example target locations A-H in FIG. 1D.

[0085] In some examples, the target tissues include hypoglossal nerves 220R, 220L, IHM-innervating nerves 224R, 224L, reflex-inducing nerves 222R, 222L (e.g., iSLN, afferent fibers of a glossopharyngeal neve), and / or phrenic nerves 226R, 226L. In some examples, the target tissues may additionally and / or alternatively include muscles innervated by or elicited as part of reflex response driven by at least some of such nerves, including but not limited to genioglossus muscle, IHMs, and diaphragm muscles. As apparent from at least the later-described sensing portion 3000 in FIG. 31 A, the example target tissues illustrated in FIG. 1D do not comprise the full range of available target tissues available for sensing.

[0086] It will be understood that the particular locations of the electrode arrangements 210R, 210L, 213R, 213L, 214R, 214L, 216R, 216L (e.g., at least one electrode) provide just one example and that such locations are also representative of many different target tissues and locations at which the respective electrode arrangement may be located consistent with accessibility of the respective nerves, muscles, other tissues, etc.

[0087] As further shown in FIG. 1D, at each of the respective locations B, D, F, H, a housing of an IMD may be securely fixed at or relative to an anchoring tissue as represented via the dashed boxes at each respective location. In some examples, the anchoring tissue may comprise a muscle such as (but not limited to) the mylohyoid, digastric, sternothyroid, sternohyoid, omohyoid, sternocleidomastoid (SCM), and / or other muscles. In some examples, the anchoring tissue may comprise non-nerve and / or non-muscle tissues such as bony structures, tendons, etc., which may include a mandible, hyoid bone, clavicle, thyroid cartilage, digastric 12 tendon, etc., at least some of which are further described in association with FIG. 1DD and / or other figures throughout examples of the present disclosure. At least for purposes of anchoring, it will be understood that locations B, D, F, H may be representative for locations A, C, E, G, respectively.

[0088] FIG. 1 DD further illustrates various anatomical features which may serve as an anchoring tissue at which an example IMD may be mounted and / or anatomical features corresponding to example target tissues to be sensed and / or stimulated. More particularly, FIG. 1DD illustrates a front view of the head-and-neck region of the patient, which includes the right mandible 232R (including end 233R), left mandible 232L (including end 233L), chin 231, hyoid bone 235, thyroid cartilage 236, clavicle 237R, 237R, and manubrium 238, each of which may comprise an anchoring tissue. As further shown in FIG. 1DD, several infrahyoid muscles (IHMs) are located in the neck region, with such muscles being innervated by an IHM-innervating nerve, which is further described below in association with FIG. 1E. The infrahyoid muscles (IHMs) include the omohyoid muscle 284 which overlies at least a portion of the sternohyoid muscle 297 and the sternothyroid muscle 294. The thyrohyoid muscle 293 may not be innervated by the IHM-innervating nerve (299 in FIG. 1E).

[0089] With these examples in mind relating to infrahyoid strap muscles and / or the IHM-innervating nerve, it will be understood that an IHM-innervating nerve may comprise a nerve or nerve branch which innervates (directly or indirectly) at least one infrahyoid muscle, which may sometimes be referred to as an infrahyoid strap muscle. In some examples, IHM-innervating nerves / nerve branches extend from (e.g., originates) from a nerve loop called the ansa cervicalis (AC) or the “AC nerve loop”, which stems from the cervical plexus, e.g., extending from cranial nerves C1-C3. Accordingly, in some examples, at least some IHM-innervating nerves may correspond to an ansa cervicalis (AC)-related nerve in the sense that such nerves / nerve branches (e.g., IHM-innervating nerves) do not form the AC nerve loop but extend from the AC nerve loop. At least because the AC nerve loop is the origin for some nerves which innervate muscles other than the infrahyoid muscles, some AC-related nerves do not comprise IHM-innervating nerves. Moreover, it will be understood that in some examples, stimulation applied to a portion (e.g., superior root) of the AC nerve loop (and / or to nerves from which the AC nerve loop originates) may activate IHM-innervating nerves / nerve branches, which extend from the AC nerve loop. However, implementing stimulation (e.g., to influence upper airway patency) occurring at more proximal locations, such as along the superior root of the AC nerve loop may be more complex because of the number / type of different nerves and number / type of different muscles innervated via a superior root of the AC nerve loop such that selective activation of a particular infrahyoid muscle (via stimulation along the superior root) may be quite challenging in some circumstances.

[0090] With this background in mind, FIG. 1E is a diagram 250 schematically representing patient anatomy and providing further details regarding example devices and / or example methods for stimulating an IHM-innervating nerve and / or hypoglossal nerve. As shown in FIG. 1E, diagram 250 includes a side view schematically representing an AC-main nerve 265, in context with a hypoglossal nerve 255 and with cranial nerves C1, C2, C3. As shown in FIG. 1E, portion 279A of the AC-main nerve 265 (e.g., a portion or trunk connecting to the AC nerve loop 269) extends anteriorly from a first cranial nerve C1 with a segment 267 running alongside (e.g., coextensive with) the hypoglossal nerve 255 for a length until the AC-main nerve 265 diverges from the hypoglossal nerve 255 to form a superior root 275 of the AC-main nerve 265, which forms part of the AC nerve loop 269. A portion of the hypoglossal nerve 255 extends distally to innervate the genioglossus muscle 254. As further shown in FIG. 1E, the superior root 275 of the AC-main nerve 265 extends inferiorly (i.e., downward) until reaching near bottom portion 268 of the AC nerve loop 269, from which the AC nerve loop 269 extends superiorly (i.e., upward) to form a lesser root 277 (i.e., inferior root) which joins to the second and third cranial nerves, C2 and C3, respectively and via portions 279B, 279C.

[0091] As further shown in FIG. 1E, several branches 281 extend off the AC nerve loop 269, including branch 282 which innervates the omohyoid muscle group 284, branch 292 which innervates the sternothyroid muscle group 294 and at least a portion (e.g., inferior portion) of the sternohyoid muscle group 297. Another branch 296, near bottom portion 268 of the AC nerve loop 269, innervates at least a portion (e.g., superior portion) of the sternohyoid muscle group 297. In some examples, the collective arrangement of the AC-main nerve 265 (including at least superior root 275 of the AC loop nerve 269) and its related branches (e.g., at least 282, 292, 296) when considered together, or any of those elements individually, may sometimes be referred to as an IHM-innervating nerve 299. It will be further understood that at least one such IHM-innervating nerve 299 is present on both sides (e.g., right and left) of the patient’s body.

[0092] In some examples, stimulation of the superior root 265 of AC nerve loop 269 and / or at least some of the branches 281 extending from the AC nerve loop 269, may influence upper airway patency. However, in some examples, upper airway patency also may be increased and / or maintained by directly stimulating the aboveidentified muscle groups, such as the omohyoid, sternothyroid, and / or sternohyoid muscle groups. Accordingly, in some examples, such stimulation also may comprise stimulation of just a nerve portion(s), just muscle portion(s), a combination of nerve portion(s) and muscle portion(s), a neuromuscular junction of nerve portion(s) and muscle portion(s), and combinations thereof. Among other effects, in some examples stimulation of such nerves and / or muscles (and / or neuromuscular junctions, combinations, etc.) may act to bring the larynx inferiorly, which may increase upper airway patency.

[0093] Stimulation may be delivered to many different locations of an IHM-innervating nerve 299 / nerve branches. Of these various potential stimulation locations, FIG. 1E generally illustrates three example stimulation locations A, B, and C. A stimulation element may be placed at all three of these locations or just some (e.g., one or two) of these example stimulation locations. At each location, a wide variety of types of stimulation elements (e.g., cuff electrode, axial array, paddle electrode, etc.) may be implanted depending on the particular delivery path, method, etc. For example, any one or a combination of the various example stimulation elements (and associated manner of access, delivery, etc.) described in association with at least FIGS. 1A-33 may be used to deliver such stimulation. 15

[0094] With further reference to FIG. 1E, at each example stimulation location A, B, C, a stimulation element may be delivered subcutaneously, intravascularly, etc. At each stimulation location, in some examples the stimulation element may comprise a microstimulator.

[0095] It will be understood that these example stimulation locations A, B, C are not limiting and that other portions along the IHM-innervating nerve 299 / nerve branches may comprise suitable stimulation locations, depending on the particular objectives of the stimulation therapy, on the available access / delivery issues, etc.

[0096] Among the different physiologic effects resulting from stimulation of the various portions of the IHM-innervating nerve 299 / nerve branches (and / or innervated muscle portions, neuromuscular junctions, etc.), in some examples stimulation of nerve branches which cause contraction of the sternothyroid muscle and / or the sternohyoid muscle may cause the larynx to be pulled inferiorly, which in turn may increase and / or maintain upper airway patency in at least some patients. Such stimulation may be applied without stimulation of the hypoglossal nerve or may be applied in coordination with stimulation of the hypoglossal nerve 255 and / or other nerves promoting upper airway patency.

[0097] FIG. 2A is a diagram schematically representing an example implantable medical device (IMD) 300a. In some examples, the IMD 300a may comprise at least some of substantially the same features as, and / or comprise an example implementation of at least some of the features of, the implantable components (e.g., 117,128) in the arrangements of FIGS. 1A-1E.

[0098] As shown in FIG. 2A, in some examples, IMD 300a includes a housing 302, a wireless communication portion 303, and a stimulation element 308. In some examples, the wireless communication portion 303 may comprise a wireless receiver 304 and / or a wireless communication element 306 (e.g., antenna). In some examples, the IMD 300a may be implanted into a patient for therapeutic and / or other suitable purposes. In some examples, via the stimulation element 308, the IMD 300a may be used to apply electrical stimulation to respiratory-related tissue, such as to an upper airway patency-related tissue of a patient, to treat sleep disordered 16 breathing (SDB) conditions. In some examples, the IMD 300a may be used to apply electrical stimulation to other tissues (e.g., pelvic, spinal) of a patient to treat other conditions (e.g., urinary and / or fecal incontinence).

[0099] The wireless receiver 304 of the wireless communication portion 303 may receive power transmitted from an external power source or charger (e.g., 174 / 150 in FIG. 1B, 3670 of FIG. 33) to power the IMD 300a including the wireless receiver 304 and the stimulation element 308. In some examples, the wireless receiver 304 also receives communications from the external charger such as in association with communication portion 176 in FIG. 1B. In some examples, the wireless receiver 304 receives power (and / or communications) using inductive coupling or near-field radio frequency (RF) wireless power transfer. In some examples, the wireless receiver 304 receives power (and / or communications) using far-field RF wireless power transfer.

[0100] The wireless communication element 306 of the wireless communication portion 303 may include a coil antenna for inductive or near-field RF wireless power transfer (e.g., for frequencies less than or equal to about 50 MHz) or an RF antenna for far-field RF wireless power transfer (e.g., for frequencies greater than or equal to about 900 MHz). In the IMD 300a, the wireless communication element 306 may be arranged on the housing 302 (e.g., on an exterior wall of the housing 302 or on an interior wall of the housing 302) or integrated within (e.g., embedded within, etched into) the housing 302. The wireless communication element 306 is electrically coupled to the wireless receiver 304 and is configured to receive power from a wireless transmitter (e.g., 174 in FIG. 1B, 3670 in FIG. 33) to power the wireless receiver 304 and the stimulation element 308. In some examples, the wireless communication element 306 may also receive communication signals and / or control signals from an external charger (e.g., 176 in FIG. 1B, 3670 in FIG. 33) or other device (e.g., a mobile device 3620, a remote control 3640, a clinician programmer 3650, and / or a patient management tool 3660 of FIG. 33).

[0101] In some examples, the wireless communication element 306 of the wireless communication portion 303 may include an inductor configured as a coil for use as an antenna for inductive wireless power transfer (WPT), inductive communications (e.g., inductive telemetry), and / or radio frequency (RF) communications (e.g., RF telemetry). The coil may be used for inductive wireless power transfer and / or inductive communications at a first frequency at or below the self-resonance frequency of the coil. The same coil may be used as an antenna for RF communications at a second frequency above the self-resonance frequency of the coil. In some examples, the second frequency may be greater than at least ten times the first frequency. In some examples, the coil may be used for inductive wireless power transfer and / or inductive communications at a first frequency within a range, for example, between about 9 kilohertz and about 50 megahertz, such as 6.78 megahertz or 13.56 megahertz. In some examples, the same coil may be used for RF communications at a second frequency within a range, for example, between about 100 megahertz and about 5 gigahertz, such as 400 megahertz or 2.4 gigahertz.

[0102] The simulation element 308 may include stimulation circuitry and / or at least one stimulation electrode to apply electrical stimulation to a patient. The stimulation element 308 receives power and / or control signals from the wireless receiver 304 of wireless communication portion 303. The electrical stimulation may be applied via at least one electrode of the stimulation element 308 or electrically coupled to the stimulation element 308. In some examples, at least one electrode (not shown) may be arranged on the housing 302 (e.g., see electrodes 970 on housing 962 of FIG. 21 described below), or as further described below with reference to at least FIG. 29, at least one electrode 2910 may be arranged on a lead 2904 electrically coupled to the stimulation element 308.

[0103] In some examples, the housing 302 encloses at least a portion of the wireless communication portion 303 (e.g., the wireless receiver 304) and at least a portion (e.g., at least stimulation circuitry) of the stimulation element 308. In some examples, housing 302 may encapsulate (e.g., overmold) the wireless receiver 304 and the stimulation element 308 to hermetically seal at least a portion (e.g., the wireless receiver 304) of the wireless communication portion 303 and at least a portion (e.g., stimulation circuitry) of the stimulation element 308. As further described below with reference to at least FIGS. 4A-7C, housing 302 may include any suitable biocompatible material, such as a metal (e.g., titanium, stainless steel, MP35N), a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., polyetheretherketone (PEEK)), a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)), or a combination thereof. Different portions of the housing 302 may be made of different materials. For example, a first portion of the housing 302 may be made of a metal (e.g., titanium) while a second portion of the housing where the wireless communication element 306 is arranged may be made of a nonconductive material (e.g., PEEK). In some examples, where the housing 302 or a portion of the housing 302 is made of an electrically conductive material (e.g., metal), the majority of the electrically conductive housing may be coated with an electrically insulating material (e.g., parylene) while leaving a section of the electrically conductive material exposed to form an electrode on the housing 302.

[0104] In some examples, the IMD 300a may include a microstimulator configured to be implanted within a patient, such as within a head-and-neck region, the torso, or pelvic region of the patient. The microstimulator may include the housing 302 to encapsulate (e.g., hermetically seal) at least a portion (e.g., wireless receiver 304) of the wireless communication portion 303 and at least a portion (e.g., stimulation circuitry) of the stimulation element 308.

[0105] FIG. 2B is a diagram schematically representing an example IMD 300b. In some examples, the IMD 300b may comprise at least some of substantially the same features and attributes as IMD 300a of FIG. 2A. As shown in FIG. 2B, the IMD 300b may include a housing 302, a wireless receiver 304, a control portion 310, and a power element 312. In some examples, the IMD 300b may be implanted into a patient for diagnostic, therapeutic, drug delivery, and / or other suitable purposes. The housing 302 encloses the power element 312, the wireless receiver 304, and the control portion 310. In this example, the wireless receiver 304 receives power transmitted from a wireless transmitter (e.g., of external charger 3670 of FIG. 33) to charge (or recharge) the power element 312. In some examples, the wireless receiver 304 also receives communications from the external charger. The wireless receiver 304 may separately receive power and communication signals from the external charger at different times or may receive (e.g., multiplexed) power and communication signals simultaneously from the external charger. In some examples, the wireless receiver 304 receives power (and / or communications) using inductive coupling or near-field radio frequency (RF) wireless power transfer. In some examples, the wireless receiver 304 receives power (and / or communications) using far-field RF wireless power transfer.

[0106] In some examples, the enclosure / case of power element 312 also forms at least a portion of housing 302 of IMD 300b. Accordingly, in this example power element 312 does not include a separate power element enclosure within the housing 302 of IMD 300b.

[0107] The control portion 310 may control the wireless receiver 304, the power element 312, and other circuitry (not shown) of the IMD 300b. In some examples, the control portion 310 may implement aspects of the example methods described below with reference to at least FIG. 28. The control portion 310 may include a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), and / or other suitable logic circuitry. At least some example implementations of the control portion 310 are further described below with reference to at least FIGS. 32A and 32B.

[0108] It will be further understood that in some examples, at least some aspects or elements of the control portion 310 may form part of, and / or be distributed among, the other components (e.g., power element 312, wireless communication portion 303, other) of the IMD 300b such that control portion 310 does not necessarily form a component of the IMD 300b separate from those other elements (e.g., power element 312, wireless communication portion 303, etc.).

[0109] The power element 312 may be a liquid electrolyte battery (e.g., lithium-ion battery), a solid-state battery, a supercapacitor, or other suitable component configured to store energy that may be used to power the IMD 300b. In some examples, the solid-state battery may comprise a thin-film solid-state electrolyte, such as (but not limited to) a lithium phosphorus oxynitride (LiPON) material. The time required to recharge the power element 312 of the IMD 300b is based upon the power element technology. For example, given a supercapacitor, a solid-state battery, and a liquid electrolyte battery each having the same energy capacity, in some examples the supercapacitor may be recharged from a 10 percent charge to a 90 percent charge faster than the solid-state battery, and the solid-state battery may be recharged from a 10 percent charge to a 90 percent charge faster than the liquid electrolyte battery. For example, when a supercapacitor is used as the power element 312, the IMD 300b may be rapidly recharged from a 10 percent charge to a 90 percent charge by the external charger in under 90 seconds for example. When a solid-state battery is used as the power element 312, the IMD 300b may be quickly recharged from a 10 percent charge to a 90 percent charge by the external charger in under 10 minutes for example. When a liquid electrolyte battery is used as the power element 312, the IMD 300b may be recharged from a 10 percent charge to a 90 percent charge by the external charger in 20 to 30 minutes for example.

[0110] In examples in which a solid-state battery is used as the power element 312, the power element 312 and thus the IMD 300b may be made smaller since solidstate batteries are more energy dense than supercapacitors and liquid electrolyte batteries. Supercapacitors and solid-state batteries are safer than liquid electrolyte batteries, since there is little risk of a liquid electrolyte leaking and the risk of fire may be reduced. Supercapacitors can withstand more charge and discharge cycles (e.g., hundreds of thousands) than solid-state batteries before degrading (e.g., storing less energy), and solid-state batteries can withstand more charge and discharge cycles (e.g., about 5000) than liquid electrolyte batteries (e.g., about 1000) before degrading. Supercapacitors have an additional benefit over both solid-state batteries and liquid electrolyte batteries in that supercapacitors do not contain any toxic metals (e.g., lithium) that may involve more special handling, sealing, etc. to permit use within a patient. In some examples, the power element 312 may include two or more 21 power storage technologies, such as a supercapacitor paired with a solid-state battery.

[0111] In some examples, an IMD 300b may comprise a power source for other IMDs in close enough proximity to be in power-exchanging relation to the IMD 300b such that IMD 300b may omit a sensing element, stimulation element, etc. and solely serve as a power resource within the patient’s body to support other IMDs within the patient’s body. In some such examples, such support to help power other IMDs within the patient may comprise the IMD 300b including a wired connection to such other IMDs, such as via a lead or other means.

[0112] Similarly, in some examples, with or without its own power element (and / or with or without elements for sensing, stimulation etc.), an IMD may provide a wireless communication node to support wireless communication with other IMDs within a patient’s body and / or wireless communication with external elements (e.g., 150 in FIG. 1B), which may support such IMDs acting as intra-body wireless communication nodes.

[0113] FIG. 2C is a diagram schematically representing an example IMD 300c. The IMD 300c is similar to the IMD 300b of FIG. 2B, except that the IMD 300c further includes stimulation element 308. In this example, the control portion 310 may include a therapy manager arranged to control the stimulation element 308 based on at least control information to apply electrical stimulation to a patient. In some examples, the therapy manager may be arranged to control (e.g., based on control information) the stimulation element 308 to apply electrical stimulation to respiratory-related tissue (e.g., upper airway patency-related tissue) to treat sleep disordered breathing (SDB) conditions or to apply electrical stimulation to other tissues, as noted above. The electrical stimulation may be applied via at least one electrode of the stimulation element 308 or electrically coupled to the stimulation element 308. In some examples, at least one electrode (not shown) may be arranged on the housing 302 (e.g., see electrodes 970 on housing 962 of FIG. 21), or as further described below with reference to at least FIG. 29, at least one electrode 2910 may be arranged on a lead 2904 electrically coupled to the stimulation element 308.

[0114] In some examples, the IMD 300c may include a microstimulator configured to be implanted within a patient, such as within a head-and-neck region, the torso, or pelvic region of the patient. The microstimulator may include the housing 302 to encapsulate (e.g., hermetically seal) at least the power element 312, the wireless communication portion 303 (e.g., wireless receiver 304 and / or wireless communication element 306), the stimulation element 308, and / or the control portion 310.

[0115] FIG. 2D is a diagram schematically representing an example IMD300d. The IMD 300d is similar to the IMD 300b of FIG. 2B, except that the IMD 300d further includes sensing element 314 and the wireless communication element 306 is integrated into or on the power element 312. In some examples, the wireless communication element 306 may be wrapped around the power element 312 or arranged on a casing of the power element 312. Alternatively, as previously described above with reference to FIG. 2A, the wireless communication element 306 may be arranged on the housing 302 or integrated within the housing 302.

[0116] In this example, the control portion 310 may include a sensing manager arranged to control the sensing element 314 based on at least control information to obtain sensing information (e.g., physiologic information) for a patient. The sensing element 314 may include sensors (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, temperature sensor, pressure sensor, etc.) and / or other suitable circuitry for obtaining sensing information for a patient. The sensing information (e.g., sensed physiologic information) may include respiratory information, cardiac information, activity information, motion information, posture information, and / or other information about the patient. In some examples, the sensing element 314 may comprise one or more of the sensing modalities, sensing functions, and / or parameters described later in association with at least sensing portion 3000 of FIG. 31 A. In some examples, the sensing element 314 of the IMD 300d may be included along with the stimulation element 308 of the IMD 300c within a single IMD. The sensing element 314 may sense information of a patient via at least one electrode electrically coupled to the sensing element 314. In some examples, at least one electrode (not shown) may be arranged on the housing 302 (e.g., see electrodes 970 on housing 962 of FIG. 21), or as further described below with reference to at least FIG. 29, at least one electrode 2910 may be arranged on a lead 2904 electrically coupled to the sensing element 314. In some examples in which a sensing element comprises at least one electrode, the at least one electrode also may, at times, be used for stimulation and / or comprise a portion of the stimulation element 308.

[0117] The sensed information may be used to initiate, terminate, pause, synchronize, and / or trigger therapy to be applied via an IMD and / or external therapy elements. In some examples, the sensed information may be used as feedback for controlling therapy (e.g., stimulation therapy), such as closed loop therapy. The sensed information also may be used for diagnostic purposes and / or for monitoring (and / or evaluation of) a particular physiologic effect, physiologic response, etc. regardless of whether the sensed information is used for other purposes (e.g., therapy). In some such examples, the sensed information may be used to evaluate open loop therapy (e.g., stimulation) which does not include a feedback loop to initiate, terminate, pause, synchronize, and / or trigger delivery of therapy.

[0118] In some examples, an IMD may comprise any one of various combinations of the above-described elements (e.g., stimulation, sensing, power, communication, control) of the respective IMDs described in association with FIGS. 2A-2D and / or FIGS. 1A-1E. In one example, a sensing element (e.g., 314 in FIG. 2D) may take the place of the stimulation element 308 of the IMD 300a in FIG. 2D, or vice versa. In another example, both the sensing and stimulation elements 314, 308 may be included in the same IMD or all three of the sensing, stimulation, and power elements 314, 308, 312 may be included in the same IMD, along with other elements such as a wireless communication portion 303 and / or control portion 310. At least some of these various combinations regarding FIGS. 1A-2D are also applicable to the various later described examples associated with FIGS. 3A-33.

[0119] FIG. 3A is a diagram schematically representing an example antenna 400 including three orthogonal coils 402a, 402b, and 402c that may be configured to receive wireless power and / or communications. In some examples, the antenna 400 may provide the wireless communication element 306 of wireless communication portion 303 of FIGS. 2A-2D. The coils 402a, 402b, and 402c may be wrapped around a power element (e.g., 312 of FIGS. 2B-2D) or a magnetic core (e.g., ferrite core) along orthogonal axes. The coils 402a, 402b, and 402c may include a single coil element (e.g., wire) with windings across the three axes, or each coil 402a, 402b, and 402c may be separate from each other (e.g., separate windings). The antenna 400 may be part of a wireless receiver (e.g., 304 of FIGS. 2A-2D) of an IMD (e.g., 300a-300d of FIGS. 2A-2D). By including orthogonal coils 402a, 402b, and 402c within an IMD, an external charger (e.g., 174 / 176 in FIG. 1B, 3670 in FIG. 33) may maintain sufficient coupling (e.g., inductive or near-field RF) with the antenna 400 independent of the orientation of the IMD due to the position and / or posture of the patient relative to the external charger. In addition, for the transmit coil(s) of an external charger that do not have field diversity in different orthogonal axes, antenna 400 provides increased receiver diversity to improve coupling for various patient positions / postures. It is noted that near-field RF wireless power transfer is more forgiving in terms of the proximity and alignment of the transmit coil(s) in the external charger and the receiver coil(s) in the IMD than inductive wireless power transfer. While coils 402a, 402b, and 402c are illustrated as having a rectangular arrangement in FIG. 3A, in some examples, coils 402a, 402b, and 402c may have another suitable geometric arrangement, such as circular, elliptical, triangular, hexagonal, etc., or a non-geometric or asymmetrical arrangement.

[0120] FIG. 3B is a diagram schematically representing an example antenna 420. In some examples, the antenna 420 may provide the wireless communication element 306 of wireless communication portion 303 of FIGS. 2A-2D. In this example, the antenna 420 includes a set of trace antennas 422a, 422b, and 422c to generate three orthogonal fields 424a, 424b, and 424c, respectively. The trace antenna 422a forms a loop coil. While the loop coil of the trace antenna 422a illustrated in FIG. 3B has a rectangular shape, in some examples, the loop coil of the trace antenna 422a may have another suitable geometric shape, such as circular, elliptical, square, triangular, hexagonal, etc., or a non-geometric or asymmetric shape. The trace antenna 422b forms a first figure-eight coil. While the figure-eight coil of the trace antenna 422b illustrated in FIG. 3B has a hexagonal shape, in some examples, the figure-eight coil of the trace antenna 422a may have another suitable geometric shape, such as circular, elliptical, rectangular, triangular, etc., or a non-geometric or asymmetric shape. The trace antenna 422c forms a second figure-eight coil orthogonal to the first figure-eight coil of the trace antenna 422b. While the figureeight coil of the trace antenna 422c illustrated in FIG. 3B has a hexagonal shape, in some examples, the figure-eight coil of the trace antenna 422c may have another suitable geometric shape, such as circular, elliptical, rectangular, triangular, etc., or a non-geometric or asymmetric shape. By combining the trace antennas 422a, 422b, and 422c generating three orthogonal fields 424a, 424b, and 424c, respectively, into an antenna 420 within an IMD, an external charger (e.g., 174 / 176 in FIG. 1B, 3670 in FIG. 33) may maintain sufficient coupling (e.g., inductive or nearfield RF) with the antenna 420 independent of the orientation of the IMD due to the position and / or posture of the patient relative to the external charger. In addition, for the transmit coil(s) of an external charger that do not have field diversity in different orthogonal axes, antenna 420 provides increased receiver diversity to improve coupling for various patient positions / postures.

[0121] FIG. 3C is a diagram schematically representing an example chip antenna 440. In some examples, the chip antenna 440 may provide the wireless communication element 306 of wireless communication portion 303 of FIGS. 2A-2D. The chip antenna 440 includes a semiconductor package 442 and a plurality of contacts 444. While the chip antenna 440 illustrated in FIG. 3C includes four contacts 444, in some examples, the chip antenna 440 may include less than four contacts (e.g., 2, 3) or more than four contacts (e.g., 5, 6, 7, 8, or more). An antenna structure, such as the antenna 420 of FIG. 3B or another suitable antenna structure, is integrated into the semiconductor package 442. In some examples, a wireless receiver (e.g., 304 of FIGS. 2A-2D) may also be integrated into the semiconductor package 442. In examples where the wireless receiver is not integrated into the semiconductor package 442, the plurality of contacts 444 may electrically couple the chip antenna 440 to the wireless receiver. In examples where the wireless receiver is integrated into the semiconductor package 442, the plurality of contacts 444 may electrically couple the chip antenna 440 to a stimulation element (e.g., 308 of FIG. 2A), a control portion (e.g., 310 of FIGS. 2B-2D), a sensing element (e.g., 314 in FIG. 2D), and / or a power element (e.g., 312 of FIGS. 2B-2D). The chip antenna 440 may be electrically coupled to other components of an IMD via a printed circuit board (PCB), a flex circuit, a silicon interposer (e.g., 630 of FIG. 10 described below), a multi-chip package, and / or another suitable interconnection structure.

[0122] FIG. 4A is a cross-sectional view and FIG. 4B is a side view schematically representing an example IMD 500 including a two-part housing 502. The IMD 500 may include an electrical element 510, such as a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a control portion (e.g., 310 of FIGS. 2B-2D), a stimulation element (e.g., 308 of FIGS. 2A or 2C), a sensing element (e.g., 314 of FIG. 2D), and / or other elements within the housing 502. The IMD 500 may also include a power element 512 (e.g., 312 of FIGS. 2B-2D) electrically coupled to the electrical element 510 within the housing 502, such that the IMD 500 may provide an IMD 300b-300d of FIGS. 2B-2D. In some examples, the power element 512 may be excluded, such that the IMD 500 may provide the IMD 300a of FIG. 2A. In some examples, the electrical element 510 and / or the power element 512 may be potted with a silicone, epoxy, or another suitable material. In some examples, the electrical element 510 and / or the power element 512 may be coated with an electrically insulating material using atomic layer deposition (ALD) or chemical vapor deposition (CVD) to improve hermeticity and / or device longevity.

[0123] In some examples, the housing 502 includes a first portion 504a and a second portion 504b welded or adhered to the first portion 504a along a seam or joint 506 to seal (e.g., hermetically seal) the first portion 504a to the second portion 504b. The first portion 504a and the second portion 504b may be made of the same material or different materials. In some examples, the first portion 504a and / or the second portion 504b may be made of a metal, such as titanium, stainless steel, MP35N, or another suitable metal. In these examples, the first portion 504a may be welded (e.g., laser welded) to the second portion 504b. In some examples, the first portion 504a and / or the second portion 504b may be made of a thermoplastic material, a thermoset material, or a blend polymer material. In these examples, the first portion 504a may be ultrasonically welded to the second portion 504b or adhered to the second portion 504b using an adhesive. In some examples, the first portion 504a and / or the second portion 504b may be made of polyetheretherketone (PEEK). In some examples, the first portion 504a and / or the second portion 504b may be made of a ceramic (e g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)). In some examples, the first portion 504a may include a metal and the second portion 504b may include at least one of a thermoplastic material, a thermoset material, or a blend polymer material. In some examples, the first portion 504a may include a metal and the second portion 504b may include at least one of silicone, PEEK, or a ceramic.

[0124] Thermoplastic material, thermoset material, or blend polymer material (e.g., PEEK) housings have advantages over metal housings including lower cost and the ability to use injection molding or thermoforming to fabricate the housings rather than machining, stamping, or die casting used to fabricate metal housings. Injection molding and thermoforming enable the housings to be formed into any desired shape, such as the shapes described below with reference to at least FIGS. 12A-21.

[0125] The first portion 504a has a first height H1, and the second portion 504b has a second height H2. While the first portion 504a and the second portion 504b of the housing 502 illustrated in FIG. 4B are the same height wherein H1 equals H2, such that the first portion 504a and the second portion 504b are joined through a midline of the housing 502 at the seam or joint 506, in some examples, the first portion 504a and the second portion 504b may be different heights wherein H1 does not equal H2. For example, the first portion 504a may provide the majority of the height (i.e., H1 > H2) of the housing 502, while the second portion 504b may provide a cap or a base portion of the housing 502, such that the first portion 504a and the second portion 504b are not joined through a midline of the housing 502. While the housing 28 502 illustrated in FIGS. 4A and 4B has a rectangular shape, in some examples, the housing 502 may have any suitable geometric shape (e.g., square, circular, elliptical, hexagonal, triangular, etc.), non-geometric shape, or asymmetrical shape.

[0126] In some examples, the interior of the first portion 504a and / or the interior of the second portion 504b of the housing 502 may be coated with an electrically insulating material using atomic layer deposition (ALD) or chemical vapor deposition (CVD) to improve hermeticity and / or device longevity. In some examples, the exterior of the first portion 504a and / or the exterior of the second portion 504b of the housing 502 may be coated with an electrically insulating material using atomic layer deposition (ALD) or chemical vapor deposition (CVD) to improve hermeticity and / or device longevity.

[0127] Consistent with at least some examples of the present disclosure which may comprise elements on an outer surface of a housing of an IMD, it will be understood that in some examples, the sealed housing 502 may be constructed to include sealed structures (e.g., feedthroughs) to permit one or more elements (e.g., conductive elements) to pass through a wall of the housing 502 (while maintaining the sealing of the housing 502) with the one or more elements being available for connection to a lead, to an antenna, and / or to other elements on an outer surface of the housing 502.

[0128] In some examples, one or more of the following examples described in association with at least FIGS. 5A-21 may comprise at least some of substantially the same features as, and / or an example implementation of at least some of the features of, the examples of FIGS. 1A-3C.

[0129] FIG. 5A is a cross-sectional view and FIG. 5B is a side view schematically representing an example IMD 520 including a two-part housing 522. IMD 520 may comprise at least some of substantially the same features as IMD 500 of FIGS. 4A and 4B. The IMD 520 may include an electrical element 510 and a power element 512 as previously described with reference to FIG. 4A within the housing 522. The housing 522 includes a first portion 524a and a first metal band 528a (e.g., first metal strip) coupled to the first portion 524a and extending around the first portion 524a. The housing 522 also includes a second portion 524b and a second metal band 528b (e.g., second metal strip) coupled to the second portion 524b and extending around the second portion 524b. The first metal band 528a and the second metal band 528b may be made of titanium, stainless steel, MP35N, or another suitable metal. The first metal band 528a is welded (e.g., laser welded) or adhered to the second metal band 528b along a seam or joint 526 to seal (e.g., hermitically seal) the first portion 524a to the second portion 524b.

[0130] The first portion 524a and the second portion 524b may be made of the same material or different materials. In some examples, the first portion 524a and / or the second portion 524b may be made of a thermoplastic material, a thermoset material, or a blend polymer material. In some examples, the first portion 524a and / or the second portion 524b may be made of polyetheretherketone (PEEK). In some examples, the first portion 524a and / or the second portion 524b may be made of a ceramic (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)). In some examples, the first portion 524a may include a metal and the second portion 524b may include at least one of a thermoplastic material, a thermoset material, or a blend polymer material. In some examples, the first portion 524a may include a metal and the second portion 524b may include at least one of silicone, PEEK, or a ceramic. In these examples including a metal first portion 524a and a non-metal second portion 524b, the first metal band 528a may be integral to (e.g., form a single unitary piece, be monolithic with) the metal first portion 524a.

[0131] In some examples, the first metal band 528a and the second metal band 528b may be partially embedded into the first portion 524a and the second portion 524b, respectively (e.g., during injection molding of the first portion 524a and the second portion 524b). In some examples, the first metal band 528a and the second metal band 528b may be adhered to the first portion 524a and the second portion 524b, respectively, via an adhesive. By welding (e.g., laser welding) metal bands 528a and 528b of the housing 522 to join the first portion 524a to the second portion 524b, exposure of the electrical element 510 and the power element 512 to potentially damaging ultrasonic energy used for directly bonding thermoplastic, thermoset, or a blend polymer materials using ultrasonic welding may be prevented.

[0132] The first portion 524a has a first height H1, and the second portion 524b has a second height H2. While the first portion 524a and the second portion 524b of the housing 522 illustrated in FIG. 5B are the same height wherein H1 equals H2, such that the first portion 524a and the second portion 524b are joined through a midline of the housing 522 at the seam or joint 526, in some examples, the first portion 524a and the second portion 524b may be different heights wherein H1 does not equal H2. For example, the first portion 524a may provide the majority of the height (i.e., H1 > H2) of the housing 522, while the second portion 524b may provide a cap or a base portion of the housing 522, such that the first portion 524a and the second portion 524b are not joined through a midline of the housing 522.

[0133] FIG. 6A is a cross-sectional view schematically representing an example IMD 540 including an overmolded housing 542. The IMD 540 may comprise at least some of substantially the same features as the IMDs of FIGS. 4A-5B, except comprising the overmolded arrangement instead of a two-part housing. In some examples, the IMD 540 may include an electrical element 510 and a power element 512 (as previously described with reference to FIG. 4A) within the housing 542. The housing 542 may be formed by injection molding a thermoplastic material (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), ora blend polymer material (e.g., PEEK) over the electrical element 510 and the power element 512 to encase or encapsulate the electrical element 510 and the power element 512. Accordingly, among other aspects, the overmolded housing 542 may comprise a single, unitary monolithic structure encapsulating the electrical element 510 and the power element 512. In some examples, the exterior of the overmolded housing 542 may be coated with an electrically insulating material using atomic layer deposition (ALD) or chemical vapor deposition (CVD) to improve hermeticity and / or device longevity.

[0134] The overmolded housing 542 provides improved mechanical robustness compared to the two-part housing 500 of FIGS. 4A and 4B and two-part housing 520 of FIGS. 5A and 5B. In addition, because the overmolded housing 542 provides a generally seamless arrangement, the overmolded housing 542 eliminates any potential ingress paths at component interfaces (e.g., at joint 506 of FIG. 4B or joint 526 of FIG. 5B).

[0135] FIG. 6B is a cross-sectional view schematically representing an example IMD 560 including an overmolded housing 562. The IMD 560 may comprise at least some of substantially the same features as the IMD 540 of FIG. 6A, except comprising an inner portion 564 and an outer portion 566 instead of a single wall housing 542. The IMD 560 may include an electrical element 510 and a power element 512 (as previously described with reference to FIG. 4A) within the housing 562. The housing 562 includes an inner housing portion 564 and an outer housing portion 566. The inner housing portion 564 may be formed by injection molding a first material including a thermoplastic material (e.g., silicone, polysulfone, liquidcrystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), or a blend polymer material (e.g., PEEK) over the electrical element 510 and the power element 512 to encase or encapsulate the electrical element 510 and the power element 512. The outer housing portion 566 may be formed by injection molding a second material, different from the first material, including a thermoplastic material (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), or a blend polymer material (e.g., PEEK) over the inner housing portion 564 to encase the inner housing portion 564. In some examples, by including both an inner housing portion 564 and an outer housing portion 566, the hermeticity of the housing 562 may be increased compared to the housing 542 of FIG. 6A.

[0136] In this example, the inner housing portion 564 may include a low temperature and / or low pressure injection moldable plastic (e.g., thermoplastic vulcanisate (TPV)), and the outer housing portion 566 may include a more durable 32 injection moldable plastic (e.g., PEEK). By using a low temperature and / or low pressure injection moldable plastic for the inner housing 564, the electrical element 510 and the power element 512 of the IMD 560 may be exposed to less potentially damaging heat and / or pressure during the injection molding process compared to the electrical element 510 and the power element 512 of the IMD 540 of FIG. 6A.

[0137] In some examples, the inner housing portion 564 may be coated with an electrically insulating material using atomic layer deposition (ALD) or chemical vapor deposition (CVD) to improve hermeticity and / or device longevity, such that the electrically insulating material is between the inner housing portion 564 and the outer housing portion 566. In some examples, the outer housing portion 566 may be coated with an electrically insulating material using atomic layer deposition (ALD) or chemical vapor deposition (CVD) to improve hermeticity and / or device longevity.

[0138] In some examples, housing 502 of FIGS. 4A and 4B and / or housing 522 of FIGS. 5A and 5B may be combined with housing 542 of FIG. 6A and / or housing 562 of FIG. 6B to increase the hermiticity of the housings (e.g., where first portion 504a / 524a and second portion 504b / 524b comprise a polymer). For example, housing 542 may be included inside housing 502 or 522, or housing 502 or 522 may be included inside housing 542.

[0139] FIGS. 7A-7C and 8 relate to example IMDs in which a wireless communication element (e.g., antenna) is configured in a particular manner relative to a housing and / or elements (e.g., lead) external of the housing. In some examples, each example of FIGS. 7A-7C and 8 may comprise at least some of substantially the same features of, and / or example implementations of, at least some of the examples of FIGS. 1A-6B and / or FIGS. 9-33.

[0140] FIG. 7A is a diagram schematically representing an example IMD 580a. The IMD 580a includes a housing 582a and a lead 586 coupled to the housing 582a. In this example, the IMD 580a includes an antenna 588 (e.g., coil antenna or other wireless communication element) arranged on and / or integrated into the lead 586. The housing 582a may include a metal (e.g., titanium, stainless steel, MP35N) enclosure 584a. Thus, by arranging and / or integrating the antenna 588 into the lead 586 rather than within the metal enclosure 584a, the magnetic field generated by the antenna 588 is not redirected or attenuated due to the metal enclosure 584a, thereby improving coupling with an external device (e.g., external element 150 in FIG. 1B and / or external charger 3670, mobile device 3620, remote control 3640, clinician programmer 3650, patient management tool 3660 of FIG. 33). In addition, by separating the antenna 588 from the housing 582a, this example arrangement also may permit implanting the antenna 588 at locations within the patient which may facilitate easier or stronger wireless communication signals. In some examples, placing the antenna 588 on and / or within lead 586 may permit reducing the size of, and / or changing a shape of, the housing 582a of the IMD 580a, in a manner which may enhance maneuvering, positioning, and / or fixating the housing 582a, lead 586, and / or antenna 588 among tissues at which the IMD 580a is implanted. For instance, by providing a reduced size (and / or altered shape) of the housing 582a (via separating the antenna 588 from being within housing 582a), the housing 582a may be implanted in some smaller or differently-shaped locations that might otherwise not be feasible, which may in turn, may increase the general implantability and / or ability to fixate the housing 582a in robust locations.

[0141] FIG. 7B is a diagram schematically representing an example IMD 580b. The IMD 580b includes a housing 582b and a lead 586 coupled to the housing 582b. In this example, the IMD 580b may include a metal (e.g., titanium, stainless steel, MP35N) enclosure 584b and an end cap 590 coupled to (e.g., co-molded with, welded to, adhered to, etc.) the metal enclosure 584b. An antenna 588 (e.g., coil antenna or other wireless communication element) is arranged within the end cap 590. The end cap 590 may be made of a non-magnetic material, such as a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., PEEK), a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)), or a combination thereof. Thus, by arranging the antenna 588 within the non-magnetic end cap 590 of the housing 582b rather than within the metal enclosure 584b, the 34 magnetic field generated by the antenna 588 is not redirected or attenuated by the metal enclosure 584b, thereby improving coupling with an external device (e.g., external charger 3670, mobile device 3620, remote control 3640, clinician programmer 3650, patient management tool 3660 of FIG. 33).

[0142] While the housing 582b illustrated in FIG. 7B has a rectangular shape, in some examples, the housing 582b may have any suitable geometric shape (e.g., square, circular, elliptical, hexagonal, triangular, etc.), non-geometric shape, or asymmetrical shape. In some examples, at least a portion of the end cap 590 may have a geometric shape which is different from a geometric shape of the enclosure 584b of housing 582b, which may facilitate providing differently shaped antennas as desired.

[0143] While FIG. 7B depicts end cap 590 as being transparent or translucent at least for illustrative purposes, the end cap 590 may comprise materials which are opaque, translucent, or transparent.

[0144] FIG. 7C is a diagram schematically representing an example IMD 580c. The IMD 580c includes a housing 582c and a lead 586 coupled to the housing 582c. In this example, the IMD 580c may include a metal (e.g., titanium, stainless steel, MP35N) enclosure 584c and a window 592 extending through the metal enclosure 584c. An antenna 588 (e.g., coil antenna or other wireless communication element) may be arranged within the housing 582c adjacent (e.g., directly adjacent) to the window 592. The window 592 may include a non-magnetic material, such as a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., PEEK), a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)), or a combination thereof. Thus, by arranging the antenna 588 adjacent to the window 592 rather than adjacent to a metal wall of the enclosure 584c, the magnetic field generated by the antenna 588 is not redirected or attenuated by the metal enclosure 584c, thereby improving coupling with an external device (e.g., external charger 3670, mobile device 3620, remote control 3640, clinician programmer 3650, patient management tool 3660 of FIG. 33). While the window 592 is illustrated on a major face of the housing 582c, in some examples, the window 592 may be arranged on a side face (e.g., perpendicular to the major face) of the housing 582c. While the window 592 is illustrated as having a rectangular shape, in some examples, the window 592 may have any suitable geometric shape (e.g., square, circular, elliptical, hexagonal, triangular, etc.), non-geometric shape, or asymmetrical shape to conform to a shape of the antenna 588.

[0145] While FIGS. 7B and 7C depict end cap 590 and window 592, respectively, as being transparent or translucent at least for illustrative purposes, the respective end cap 590 or window 592 may comprise materials which are opaque, translucent, or transparent. In some examples, by forming the end cap 590 (or window 592) of a material, color, and / or opacity different from a material, color, and / or opacity of enclosure 584b (or enclosure 584c), one can more readily position and fixate IMD 580b (or IMD 580c) in a manner which places the antenna 588 in a preferred orientation that may enhance wireless power transfer and / or communication.

[0146] FIGS. 7D and 7E relate to example IMDs in which an acoustic sensor (e.g., microphone, piezoelectric sensor) is configured in a particular manner relative to a housing. In some examples, each example of FIGS. 7D and 7E may include at least some of substantially the same features of, and / or example implementations of, at least some of the examples of FIGS. 1A-7C and / or FIGS. 8-33.

[0147] FIG. 7D is a diagram schematically representing an example IMD 580d. The IMD 580d includes a housing 582d and a lead 586 coupled to the housing 582d. In this example, the IMD 580d includes an acoustic sensor 596 (e.g., microphone, piezoelectric sensor) arranged in and / or integrated into the housing 582d. In some examples, acoustic sensor 596 may be an example implementation of sensing element 128 of FIG. 1B or sensing element 314 of FIG. 2D. In some examples, acoustic sensor 596 may be included as part of an electrical element 620 of FIG. 10 described below.

[0148] The housing 582d may include an enclosure 584d including a non-magnetic material, such as a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., PEEK), a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)), or a combination thereof. In this example, the acoustic sensor 596 (and other components within the enclosure 584d) may be encapsulated within a potting material (e.g., epoxy, polyurethane, liquid crystal polymer (LCP), or silicone, etc.), such that the potting material completely fills any empty space between the acoustic sensor 596 and inner sidewalls of the enclosure 584d. In this way, acoustic energy transferred (e.g., from tissue of a patient) to the enclosure 584d is further transferred via the potting material to the acoustic sensor 596, which can generate a sensor signal corresponding to the acoustic energy. The sensor signal, which may correspond to physiologic information, may include respiratory information, cardiac information, and / or other information about the patient.

[0149] FIG. 7E is a diagram schematically representing an example IMD 580e. The IMD 580e includes a housing 582e and a lead 586 coupled to the housing 582e. In this example, the housing 582e may include an enclosure 584e including a nonmagnetic material, such as a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., PEEK), a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)), or combination thereof. The housing 582e may also include a window 598 extending through the non-magnetic enclosure 584e. An acoustic sensor 596 may be arranged within the housing 582e adjacent (e.g., directly adjacent) to the window 598.

[0150] The window 598 may mimic the density / consistency of the surrounding tissue and match the impedance of the surrounding tissue to minimize acoustic energy scattering. In some examples, the window 598 may include a metal (e.g., titanium, stainless steel, MP35N). In some examples, the metal window 598 may have a thickness within a range between about 0.05 millimeters and about 0.2 millimeters, such as about 0.1 millimeters. In some examples, the window 598 may include a polymeric material. In some examples, the polymeric window 598 may have a thickness within a range between about 0.4 millimeters and about 0.6 millimeters, such as about 0.5 millimeters. In the example of FIG. 7E, the acoustic sensor 596 (and other components within the enclosure 584e) may not be encapsulated within a potting material, such that air fills any empty space between the acoustic sensor 598 and the inner sidewalls of the enclosure 584e and the window 598. In this way, acoustic energy transferred (e.g., from tissue of a patient) to the window 598 is further transferred via the air within the enclosure 584e to the acoustic sensor 596, which can generate a sensor signal corresponding to the acoustic energy.

[0151] While the window 596 is illustrated on a major face of the housing 582e, in some examples, the window 598 may be arranged on a side face (e.g., perpendicular to the major face) of the housing 582e. While the window 598 is illustrated as having a rectangular shape, in some examples, the window 598 may have any suitable geometric shape (e.g., square, circular, elliptical, hexagonal, triangular, etc.), nongeometric shape, or asymmetrical shape.

[0152] FIG. 8 is a diagram schematically representing additional details of the IMD 580c of FIG. 7C. As previously described, the IMD 580c includes a metal enclosure 584c, a non-magnetic material window 592 extending through the metal enclosure 584c, and an antenna 588 adjacent to the window 592. Due to the window 592, a magnetic field 594 generated by the antenna 588 is not redirected or attenuated by the metal enclosure 584c.

[0153] FIG. 9 is a diagram schematically representing an example solid-state battery 600. In some examples, the solid-state battery 600 may be used for power element 312 of IMDs 300b-300d of FIGS. 2B-2D or for power element 512 of IMDs 500, 520, 540, or 560 of FIGS. 4A-6B. The solid-state battery 600 includes a cathode 602, a solid electrolyte 604 (e.g., LiPON), and an anode 606. By using a solid electrolyte rather than a liquid electrolyte, the solid-state battery 600 may provide higher energy density, reduced heat generation, higher voltage, and / or reduced charging time compared to a similarly sized liquid electrolyte battery. Thus, an IMD including the solid-state battery 600 may be made smaller than an IMD including a liquid electrolyte battery having the same energy storage capacity as the solid-state battery 600. In addition, the solid-state battery 600 may be shaped to conform to a shape of the housing of an IMD. For example, the solid-state battery 600 may have a non-geometric shape or an asymmetric shape. Among other things, the ability to select such custom shapes of battery 600 may enhance an ability to maneuver, position, and fixate a housing of an IMD because the size and / or shape of the example battery 600 places fewer constraints on a size and / or shape of the housing within which the battery will be contained. Therefore, sizes and / or shapes of a housing of an IMD may be selected to enhance maneuvering, positioning, and / or fixating the IMD relative to the specific sizes and / or shapes of the particular target tissues which will receive the IMD.

[0154] FIG. 10 is a diagram schematically representing an example electrical element 620 for an IMD. The electrical element 620 may include a wireless receiver (e.g., 304 of FIGS. 2A-2D) of a wireless communication portion 303, a control portion (e.g., 310 of FIGS. 2B-2C), a stimulation element (e.g., 308 of FIGS. 2A or 2C), a sensing element (e.g., 314 of FIG. 2D, including a sensor such as (but not limited to) accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), an antenna (e.g., 420 of FIG. 3B or 440 of FIG. 3C), and / or other electrical components. In some examples, the sensing element may be implemented via one or more of the modalities, functions, etc. of sensing portion 3000 of FIG. 31 A.

[0155] In some examples, the electrical element 620 may provide the electrical element 510 of FIGS. 4A-6B. The electrical element 620 may include a substrate 622, a silicon interposer 630, and a plurality of semiconductor chips 650a-650c. The plurality of semiconductor chips could either be standalone or packaged within a diestack arrangement. The substrate 622 may include a dielectric material, such as a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)), a polymer material, or another suitable non-conductive material. A redistribution layer 624 (e.g., a patterned copper layer) may be arranged on the substrate 622.

[0156] The silicon interposer 630 may include a substrate body 631 and contacts 632, a redistribution layer 633, through silicon vias (TSVs) 634, contacts 636, a ground layer 638, a power layer 640, a first metal layer 642, a second metal layer 644, interconnects 646, and contacts 648 within the substrate body 631. The contacts 632 are exposed on the bottom surface of the silicon interposer 630 and are electrically coupled to the redistribution layer 624 through solder balls or bumps 626. The redistribution layer 633 may electrically couple one or more contacts 632 to a corresponding TSV(s) 634. Each TSV 634 may electrically couple a contact 632 and / or the redistribution layer 633 to a corresponding contact 636. The ground layer 638 provides a ground or reference node for electrically coupling to a ground or reference (e.g., negative) terminal of a power element (e.g., 312 of FIGS. 2B-2D, 512 of FIGS. 4A-6B, or solid-state battery 600 of FIG. 9) for powering the electrical element 620. The power layer 640 provides a supply node for electrically coupling to a supply (e.g., positive) terminal of the power element for powering the electrical element 620. The first metal layer 642 and the second metal layer 644 are redistribution layers. The first metal layer 642, the second metal layer 644, and the interconnects 646 electrically couple each contact 648 exposed on the upper surface of the silicon interposer 630 to another contact (or contacts) 648, to ground layer 638, to power layer 640, and / or to a contact (or contacts) 636.

[0157] Each semiconductor chip 650a-650c includes a semiconductor package 656a-656c and exposed contacts 654a-654c, respectively. Each semiconductor chip 650a-650c is electrically coupled to corresponding contacts 648 of the silicon interposer 630 through solder balls or bumps 652a-652c, respectively. Each semiconductor chip 650a-650c may provide a different electrical component of the IMD. For example, the semiconductor chip 650a may include a sensing element (e.g., 314 in FIG. 2D such as accelerometer, gyroscope, microphone, etc.), the semiconductor chip 650b may include a control portion (e.g., 310 of FIG. 2B-2D), and the semiconductor chip 650c may include a stimulation element (e.g., 308 of FIG. 2A or 2C). In some examples, the semiconductor chip 650a may include a wireless receiver (e.g., 304 of FIGS. 2A-2D), the semiconductor chip 650b may include a control portion (e.g., 310 of FIG. 2B-2D), and the semiconductor chip 650c may include a stimulation element (e.g., 308 of FIG. 2A or 2C). In some examples, the semiconductor chip 650a may include a sensing element (e.g., 314 of FIG. 2D such as accelerometer, gyroscope, microphone, etc.), the semiconductor chip 650b may include a control portion (e.g., 310 of FIG. 2B-2D), and the semiconductor chip 650c may include other circuitry. In some examples, the semiconductor chip 650a may include an antenna (e.g., 440 of FIG. 3C), the semiconductor chip 650b may include a wireless receiver (e.g., 304 of FIG. 2A-2D), and the semiconductor chip 650c may include a stimulation element (e.g., 308 of FIG. 2A or 2C).

[0158] It is noted that the silicon interposer 630 may interconnect a variety of semiconductor chips of an IMD and is not limited to the specific examples described above. In addition, while the silicon interposer 630 illustrated in FIG. 10 electrically interconnects three semiconductor chips 650a-650c, in some examples, the silicon interposer 630 may electrically interconnect less than three semiconductor chips (e.g., 2 semiconductor chips) or more than three semiconductor chips (e.g., 4, 5, 6, or more). In addition, additional discrete components (not shown), such as capacitors, resistors, inductors, antennas (e.g., antenna coils, trace antennas, etc.), sensors, etc. may also be electrically coupled to contacts 648 of the silicon interposer 630 or formed directly on or within the silicon interposer 630.

[0159] In some examples, the silicon interposer 630 may be fabricated using a silicon wafer and wafer level fabrication techniques, such as photolithography, etching, and deposition processes and / or by using direct wafer bonding techniques, where multiple prepared silicon wafers are adhered directly to each other. The silicon interposer 630 may be used to interconnect semiconductor chips 650a-650c in place of a printed circuit board (PCB) and / or flex circuits.

[0160] Flex circuits may include alternating layers of adhesive and insulation (e.g., polyimide) in which copper traces and through holes are formed as part of the layers that results in a flexible, conductive substrate. Electrical components (e.g., semiconductor chips, passive components, etc.) are then surface mounted on the flex circuit via a surface mount technology (SMT) process. Flex circuits may be 41 folded to expand in the vertical direction, but this folding is not efficient and may require a rigid substrate (e.g., PCB) for each layer in the stack and an air gap between each layer of the stack resulting in a relatively large rigid-flex printed circuit board assembly (PCBA).

[0161] In contrast, direct wafer bonding (in at least some examples of the present disclosure) uses chemical processes to adhere layers of silicon directly to one another, removing the need for intermediary adhesive layers. Direct wafer bonding and / or wafer level fabrication techniques enable layering of traces and through holes within the silicon interposer 630 resulting in a thinner and smaller single silicon chip package substrate compared to a PCB, flex, or rigid-flex assembly. The electrical components are then mounted onto the single silicon chip package. The silicon interposer 630 results in a thinner substrate than a flex circuit stack. The discrete semiconductor chips 650a-650c are surface mounted to the silicon interposer 630, similar to flex circuits, but the pitch of the contact pads 648 of the silicon interposer 630 may be smaller, allowing for denser packing of the components. Additionally, the silicon interposer 630 has higher reliability for closely packed components than a flex circuit.

[0162] FIGS. 11A-11D relate to example IMDs in which multiple electrical elements are provided within a housing, multiple elements (e.g., lead) may be external of the housing, and / or the respective housings may comprise different shapes, etc. In some examples, each example of FIGS. 11A-11D may comprise at least some of substantially the same features of the examples of FIGS. 1A-10 and / or FIGS. 12A-33.

[0163] Moreover, while the following examples of FIGS. 11A-11D relate primarily to example arrangements of IMDs which include a silicon interposer subassembly (e.g., 620 of FIG. 10), it will be understood that these examples of FIGS. 11 A-11D may comprise at least some of substantially the same features of, and / or example implementations of, at least some of the examples of FIGS. 1A-10 such that the examples of FIGS. 11 A-11D are not strictly limited to including a silicon interposer 42 subassembly (i.e., the silicon interposer subassembly can be omitted from some examples of FIGS. 11A-11D).

[0164] FIG. 11A is a diagram schematically representing an example IMD 670a. As shown in FIG. 11 A, in some examples, the IMD 670a includes a housing 672a and a lead 674. However, the lead 674 may be omitted in favor of an electrode contact exposed on a surface of housing 672a, in some examples. The housing 672a comprises a generally rectangular cross-sectional shape, and therefore may form a three-dimensional generally rectangular cuboid. In some examples, a portion or layer at least partially defining the housing 672a may comprise a dielectric material.

[0165] As further shown in FIG. 11 A, in some examples, the IMD 670a includes a power element 676a (e.g., 312 of FIGS. 2B-2D, 512 of FIGS. 4A-6B, or solid-state battery 600 of FIG. 9) electrically coupled to an electrical element 678a including a standalone silicon interposer subassembly (e.g., 620 of FIG. 10). By including an electrical element 678a including a silicon interposer, the overall size (e.g., length, width, and / or height) of the housing 672a may be reduced compared to a housing enclosing an electrical element not including a silicon interposer (e.g., a PCB, flex, or rigid-flex subassembly). In addition, where the power element 676a is a solidstate battery, the overall size of the housing 672a may be further reduced compared to a housing enclosing a power element including a liquid electrolyte battery. While the housing 672a illustrated in FIG. 11A comprises a generally rectangular cuboid shape, in some examples, the power element 676a and the electrical element 678a may be enclosed within a housing having another shape, such as (but not limited to) described below with reference to at least FIGS. 12A-21.

[0166] FIG. 11B is a diagram schematically representing an example IMD 670b. In some examples, the IMD 670b may comprise at least some of substantially the same features as IMD 670a, as described above, such as a housing 672b and a lead 674. The IMD 670b includes a power element 676b (e.g., 312 of FIGS. 2B-2D, 512 of FIGS. 4A-6B, or solid-state battery 600 of FIG. 9) electrically coupled to an electrical structure 678b. In some examples, the electrical structure 678b includes a structural subassembly 680 electrically coupled to the power element 676b, a first electrical element 682a including a first silicon interposer subassembly (e.g., 620 of FIG. 10), and a second electrical element 682b including a second silicon interposer subassembly (e.g., 620 of FIG. 10). The first electrical element 682a may be electrically coupled to the second electrical element 682b via the structural subassembly 680. In some examples, by using the two electrical elements 682a and 682b, each of the electrical elements 682a and 682b may be smaller than a single electrical element (e.g., 678a of FIG. 11A). By making each electrical element 682a and 682b smaller, the electrical elements may be arranged within the housing 672b such that the overall size (e.g., length, width, and / or height) of the housing 672b may be reduced compared to a housing enclosing a single larger electrical element (e.g., 678a of FIG. 11 A). Further, in some examples, electrical elements 682a and 682b each include a silicon interposer such that the overall size of the housing 672b may be reduced compared to a housing enclosing electrical elements not each including a silicon interposer (e.g., a PCB, flex, or rigid-flex subassembly). In addition, in some examples in which power element 676b comprises a solid-state battery, the overall size of the housing 672b may be further reduced compared to a housing enclosing a power element including a liquid electrolyte battery. While the housing 672b illustrated in FIG. 11B is rectangular shaped, in some examples, the power element 676b and the electrical structure 678b may be enclosed within a housing having another shape, such as (but not limited to) described below with reference to at least FIGS. 12A-21.

[0167] In some examples, a respective one of the electrical elements 682a, 682b may comprise a first type of function such as a sensing element while the other respective electrical element 682a, 682b may comprise a second type of function, such as wireless communication. In some examples, the electrical element 682b closest to lead 674 may provide a function related to the lead. For instance, in examples in which the lead 674 may comprise a stimulation lead, the electrical element 682b may comprise a stimulation element implemented as stimulation circuitry while the electrical element 682a at the opposite end of the housing 672b 44 may provide some function unrelated to stimulation because the electrical element 682a is located remotely from lead 674. For instance, the electrical element 682a may comprise a wireless communication portion 303.

[0168] However, in some examples, as previously described in association with at least FIG. 10, one or both of the electrical elements 682a, 682b may comprise multiple functions, such as both sensing and stimulation or both wireless communication and stimulation, and so on.

[0169] In some examples, the electrical element 682a at a first end 673a of housing 672b may comprise a first stimulation element while the electrical element 682b at the opposite second end 673b of housing 672b may comprise a second stimulation element. In some such examples, as further shown in FIG. 11C, an IMD 670c similar to IMD 670b may comprise two leads 674a and 674b. The additional lead 674a is electrically (and mechanically) connected at end 673a to the electrical element 682a (e.g., first stimulation element), such that the arrangement of electrical elements 682a, 682b (e.g., first and second stimulation elements) being at opposite ends 673a, 673b of the housing 672c enable two separate leads 674a, 674b (e.g., stimulation leads) to extend from the opposite ends 673a, 673b of housing 672c.

[0170] Among other things, this example arrangement of IMD 670c may facilitate use of a single housing 672c, which includes power and stimulation elements, to support two separate leads which extend in different orientations (e.g., opposite directions) to be in relation (e.g., stimulating relation, sensing relation, etc.) to two different target tissues. In some example implementations, the arrangement of example IMD 670c may facilitate bilateral stimulation and / or bilateral sensing such as when a first target tissue is located on a first side (e.g., left side) of the patient and a second target tissue is located on a second side (e.g., right side) of the patient. The housing 672c may be implanted along or near a sagittal midline of the patient with a first lead (e.g., 674a) extending from one end 673a (or side 673c) of housing 672c extending within a left side of the body to be placed in operable relation (e.g., stimulating relation, sensing relation) to a first target tissue and second lead (e.g., 674b on opposite end 673b (or side 673d) of housing 672c) extending within a right side of the body to be placed in operable relation (e.g., stimulation relation and / or sensing relation) to a second target tissue on the right side of the patient. The first target tissue (on first side) and second target tissue (on second, opposite side) may be the same type of nerve (e.g., HGN, or IHM). However, in some examples, the first and second target tissues may comprise different types of nerves, such as (but not limited to) an infrahyoid muscle (IHM)-innervating nerve on one side of the patient’s body and a different type of nerve, such as a phrenic nerve (to be sensed and / or stimulated) on the other side of the patient’s body.

[0171] However, in some examples, both leads 674a, 674b of IMD 670c can be placed on a single (e.g., same) side of a patient with the housing 672c implanted at some location between (e.g., midway or central) between the two spaced apart target tissues. The target tissues may comprise the same type of nerve, e.g., different branches of an IHM-innervating neve or may be different types of nerves, such as one target tissue comprising an IHM-innervating nerve and a hypoglossal nerve (HGN) comprising the second target tissue.

[0172] It will be understood that the IMD 670c (FIG. 11C) is not limited to a configuration in which the two separate electrical elements 682a, 682b are located at opposite ends 673a, 673b of housing 672c. Rather, in some examples, one electrical element 682a may be extend along one side wall (e.g., 673c or 673d) while the other electrical element 682b may extend along an end wall (e.g., 673a or 673b) of housing 672c. In some such examples, the arrangement may support two different leads (e.g., 674a, 674b) which extend outwardly in perpendicular orientations relative to each other. Moreover, it will be understood that in some examples, an angle of different orientations of the respective multiple leads relative to each other may be non-perpendicular (such as obtuse, acute, etc.) to achieve a desired placement of each respective lead 674a, 674b relative to a target tissue. In some examples, one can use such an example arrangement to enable two separate leads 674a, 674b to originate from the housing with different orientations but be positionable to become oriented to arrive at or near the same target tissue, such as at opposite sides of a single / same target tissue.

[0173] FIG. 11D is a diagram schematically representing an example IMD 670d. In some examples, IMD 670d may comprise at least some of substantially the same features as, and / or provide an example implementation of at least some of the features of, one (or a combination of) the IMDs 670a, 670b, 670c of FIGS. 11A-1C, except with IMD 670d including a housing 672d comprising a generally circular cross-sectional shape. In some examples, the housing 672d may comprise a threedimensional shape forming a disc or sphere. In some such examples, the general disc or sphere shape may facilitate nesting within (or relative to) a recessed (e.g., concave) anchoring tissue to enhance fixation of the housing 672d via anchoring element(s) (e.g., tines, barbs, sutures, etc.) and / or other anchoring elements.

[0174] As further shown in FIG. 11D, in some examples the housing 672d further comprises a protrusion 685. In some examples, the housing 672d may comprise other arcuate shapes. In some examples, the protrusion 685 may comprise a generally triangular cross-sectional shape as shown in FIG. 11D or other shapes. In some examples, the protrusion 685 may comprise a rounded shape instead of the generally triangular cross-sectional shape depicted in FIG. 11D. In some examples, the protrusion 685 is omitted. As in the prior examples of FIGS. 11 A-11C, the IMD 670d may comprise a lead 674 and / or an electrode exposed on a surface of the housing 672d.

[0175] In some examples, the IMD 670d includes a power element 676d (e.g., 312 of FIGS. 2B-2D, 512 of FIGS. 4A-6B, or solid-state battery 600 of FIG. 9) within a portion of the housing 672d electrically coupled to a modular electrical structure 678d within the same portion of the housing 672d. As shown in FIG. 11D, in some examples this arrangement may be located at least partially within the protrusion 685 of the IMD670d.

[0176] As further shown in FIG. 11D, the modular electrical structure 678d includes a first electrical element 684a including a first silicon interposer subassembly (e.g., 620 of FIG. 10) and a second electrical element 684b including a second silicon interposer subassembly (e.g., 620 of FIG. 10). The first electrical element 684a may be electrically coupled to and juxtaposed adjacent to (e.g., perpendicular in some examples) to the second electrical element 684b in one portion (e.g., one end portion) of the housing 672d. By using the two electrical elements 684a and 684b, each of the electrical elements 684a and 684b may be smaller than a single electrical element (e.g., 678a of FIG. 11 A). By making each electrical element 684a and 684b smaller, the electrical elements may be arranged within the housing 672d such that the overall size (e.g., diameter, and / or height) of the housing 672d may be reduced compared to a housing enclosing a single larger electrical element (e.g., 678a of FIG. 11 A). Further, in some examples, the electrical elements 684a and 684b each include a silicon interposer such that the overall size of the housing 672d may be reduced compared to a housing enclosing electrical elements not each including a silicon interposer. In addition, in some examples the power element 676d may comprise a solid-state battery such that the overall size of the housing 672d may be further reduced compared to a housing enclosing a power element including a liquid electrolyte battery. While the housing 672d illustrated in FIG. 11D comprises a generally circular cross-sectional shape, in some examples, the power element 676d and the modular electrical structure 678d may be enclosed within a housing having another shape, such as (but not limited to) described below with reference to at least FIGS. 12A-21.

[0177] In some examples, the electrical elements 684a, 684b may comprise an arcuate shape having a curvature that at least partially or completely corresponds to an arcuate shape of housing 672d. The power element 676d and / or a wireless communication element (e.g., antenna) may have a circular or oval shape, such that the shape of the housing 672d at least partially conforms to the shape of the power element 676d and / or the wireless communication element to simplify manufacture of the IMD 670d. In some examples, by conforming the shape of housing 672d to the shape of the wireless commination element, the wireless communication element may be oriented for optimal gain.

[0178] In some examples, the various examples of FIGS. 11A-11D also are applicable to leadless IMDs in which a stimulation element, sensing element, or other feature, which might otherwise have been present on a lead, is instead incorporated on and / or within a housing of an IMD. In some such examples, at an end or other portion of a housing where a lead (e.g., 674 in FIG. 11D) might have otherwise extended, the IMD may comprise at least one electrode for sensing and / or stimulation on an outer surface of the housing (e.g., 672d in FIG. 11D) such that the exteriorly-exposed, at least one electrode will be in close proximity to the respective electrical elements (e.g., 684a, 684b in FIG. 11D) to conserve space and simplify construction of the housing (e.g., 672d) of the IMD (e.g., 670d). This example arrangement also may be applied to the examples of FIGS. 11 A, 11B, 11C in implementations in which no lead is present.

[0179] In some examples, the example arrangements of IMDs 670a, 670b, 670c, 670d may be easier to anchor within a patient’s body because of reduced size (i.e., smaller volume), which in turn may permit less force to be used to fixate the IMD (and / or lead) relative to available tissues. Moreover, the reduced size of such example IMDs also may increase the options of the types and / or locations of tissues within the patient to which the IMD and / or lead may be anchored.

[0180] FIGS. 12A-12E are various views schematically representing an example IMD 700. FIG. 12A is a bottom view, FIG. 12B is a top view, FIG. 12C is a front view, FIG. 12D is a side view, and FIG. 12E is an isometric view of the IMD 700. The IMD 700 may comprise at least some of substantially the same features as, and / or an example implementation of at least some of the features of, the various examples of at least FIGS. 1A-11D and 23A-33.

[0181] The IMD 700 includes a housing 702, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 20), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D), such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The wireless communication portion 303 may comprise a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 30). The housing 702 may include a two-part 49 housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B).

[0182] In some examples, the IMD 700 may comprise one or more leads (e.g., 674 in FIGS. 11A-11D) electrically connected to at least some of the various elements within housing 702 of IMD 700, with such lead(s) carrying a stimulation electrode and / or sensing element, or other functional element.

[0183] As shown in FIGS. 12A-12E, in some examples the housing 702 includes a first face portion 704 (e.g., bottom face or first outer wall), a convex second face portion 706 (e.g., top face or second outer wall) opposite to the first face portion 704, a first anchor wing 710a coupled to a first side of the first face portion 704, and a second anchor wing 710b coupled to a second side of the first face portion 704 opposite to the first side. The first anchor wing 710a is for fixation of the housing 702 within a patient via at least one first suture, and the second anchor wing 710b is for fixation of the housing 702 within the patient via at least one second suture. In some examples, the housing 702 may further include a third anchor wing (not shown) coupled to a third side of the first face portion 704 extending between the first side and the second side and / or a fourth anchor wing (not shown) coupled to a fourth side of the first face portion 704 opposite to the third side, such that the housing 702 includes four anchor wings.

[0184] The first face portion 704 is coupled to (e.g., integral to, adhered to, welded to) the second face portion 706 to form an enclosure 702a having a length L1, a width W1 (FIG. 12A), and a maximum height H3 (FIG. 12C) (e.g., at the center of the housing 702). In one aspect, the second face portion 706 protrudes upward from the anchor wing portions 710a, 710b by a height H4 (FIG. 12D).

[0185] In some examples, the length L1 is greater than the width W1, and the width W1 is greater than the height H3. In some examples, the length L1 is at least 1.5 times, 2 times, 3 times, or 4 times the width W1. In some examples, the length L1 may be less than or equal to the width W1, and / or the width W1 may be less than or equal to the height H3.

[0186] In some examples, the height H3 (e.g., thickness) of housing 702 at center portion 706e of first convex face portion 706 is not more than 3 times (or 4 times or 5 times) a height (e.g., thickness) of anchor wing portions 710A, 712B. In some examples, the height H3 (e.g., thickness) of housing 702 at central portion 706e of first convex face portion 706 is no more than one-half the length L1 of the housing 702. Via these example arrangements, the housing 702 provides a profile (e.g., thickness) which is not overly intrusive or disruptive to the natural state, position, etc. of the anchoring tissue (e.g., 720 in FIGS. 12F-12G).

[0187] As best illustrated in FIG. 12C, in some examples the first face portion 704 may comprise an arcuate shape such as, for example, a continuous curve across the width W1 of the enclosure that is the same along the entire length L1 of the enclosure. In one aspect, the arcuate first face portion 704 may have a convexity which extends contiguously with the convex arcuate shape of bottom face portion 714 (e.g., surface) of anchor wing portions 710a, 710b, which are further described below. In contrast, the second face portion 706 of housing 702 may comprise a convex shape which protrudes (e.g., extends upward and away from) from the top face portion 716 of anchor wing portion 710a, 710b, as further described below, such that central planar segment 706e does not extend in the same plane as, or contiguously with, the top face portion 716 of anchor wing portions 710a, 710b.

[0188] As best illustrated in FIGS. 12Band12E, in some examples the second face portion 706 may be a segmented convex face portion including segments 706a-706e. The segments 706a-706e include a trapezoidal shaped convex first segment 706a, a trapezoidal shaped convex second segment 706b, a trapezoidal shaped convex third segment 706c, a trapezoidal shaped convex fourth segment 706d, and a rectangular shaped planar fifth segment 706e. The first segment 706a is opposite to the second segment 706b, and the third segment 706c is opposite to the fourth segment 706d. The first segment 706a and the second segment 706b each extend between the third segment 706c and the fourth segment 706d. The first segment 706a is adjacent to the first anchor wing 710a, and the second segment 706b is adjacent to the second anchor wing 710b. The fifth segment 706e is arranged in the center of the second convex face portion 706 and extends between and connects the first segment 706a, the second segment 706b, the third segment 706c, and the fourth segment 706d. In some examples, the transitions between the segments 706a-706e are omitted such that the second face portion 706 is a smooth and continuous convex face portion. The convex second face portion 706 increases the internal volume of the IMD 700 (compared to if second face portion 706 were flat), provides robustness against mechanical stresses, and assists in satisfying requirements for smoothness of implantable products.

[0189] As further shown in FIGS. 12A-12E, the housing 702 comprises opposite side portions 708a, 708b, and opposite end portions 709a, 709b. In some examples, the portion of the housing 702 defined by the first face portion 704, second face portion 706, segments 706a-706e, side portions 708a, 708b, end portions 709a, 709b work together to define an enclosure 702a (e.g., sealed hollow interior for containing elements). Accordingly, in some such examples, the anchor wings 710a, 710b may sometimes be referred to as extending outward from the ends 709a, 709b of the enclosure 702a of the housing 702.

[0190] As best illustrated in FIGS. 12Aand 12B, the first anchor wing 710a and the second anchor wing 710b may include rectangular shaped structures having a length L2 and a width W2 protruding from opposing sidewalls of the enclosure formed by the first face portion 704 and the second face portion 706. The length L2 of each anchor wing 710a and 710b is greater than the width W2 of each anchor wing 710a and 710b. The length L2 of each anchor wing 710a and 710b may be less than or equal to the width W1 of the enclosure. In some examples, the first anchor wing 710a and the second anchor wing 710b may include structures having another suitable shape, such as triangular, trapezoidal, half circular, etc., protruding from opposing sidewalls of the enclosure formed by the first face portion 704 and the second face portion 706. In some examples as best illustrated in FIGS. 12A, 12C, and 12D, each anchor wing 710a and 710b may be integral to (e.g., form a single unitary structure or monolithic structure with) the convex first face portion 704 and include a bottom face 714 corresponding to the convex shape of the convex first face portion 704 and a concave top face 716 opposite to the bottom face 714. In some examples, the length L1 of the enclosure plus two times the width W2 of the anchor wings 710a and 710b provides an overall length of the housing 702 of less than or equal to 4 centimeters. In some examples, the width W1 of the housing 702 is less than or equal to 2 centimeters and the maximum height H3 of the housing 702 is less than or equal to 2 centimeters.

[0191] In some examples, each anchor wing 710a and 710b includes three through holes 712 (e.g., suture anchor points) extending through each anchor wing 710a and 710b from the bottom face 714 to the top face 716. While the through holes 712 illustrated in FIGS. 12A, 12B, and 12E are circular in shape, in some examples, the through holes 712 may have another suitable shape, such as elliptical, oval, rectangular, triangular, hexagonal, etc. In some examples, the first anchor wing 710a and the second anchor wing 710b may each include less than three through holes 712, such as one through hole centered on each anchor wing 710a and 710b or two through holes on opposing sides of each anchor wing 710a and 710b. In some examples, the first anchor wing 710a and the second anchor wing 710b may each include more than three through holes 712, such as 4, 5, or 6 through holes evenly spaced across each anchor wing 710a and 710b or distributed across each anchor wing 710a and 710b in another suitable arrangement. In some examples, the greatest cross-sectional dimension of each through hole 712 is less than or equal to 5 millimeters. In some examples, the greatest cross-sectional dimension of each through hole 712 is greater than 5 millimeters. A suture (727 in FIG. 12G) may penetrate and / or be wrapped in / around patient tissue and through a through hole 712 to fix the housing 702 relative to anchoring tissue, as further described below in association with at least FIGS. 12F-12G.

[0192] In some examples, the housing 702 is configured for fixation relative to an anchoring tissue 720 (represented via dashed line), as shown in FIGS. 12F-12G. FIG. 12F is a top view schematically representing releasable engagement of the housing 702 of IMD 700 relative to the anchoring tissue 720 such as (but not limited to) a muscle belly of a muscle in close proximity to a target tissue to be sensed and / or stimulated via the IMD 700. Meanwhile, FIG. 12G is a diagram including a side view schematically representing an anchoring tissue 720 against which the housing 702 is generally anchored. As seen in FIGS. 12F-12G, with second face portion 706 (of housing 702 of IMD 700) pressingly engaged against surface 723 of anchoring tissue 720 to be oriented toward deeper tissues, the first face portion 704 (of housing 702 of IMD 700) faces outward toward superficial tissues (e.g., closer to the skin).

[0193] It will be understood that the housing 702 may be mounted relative to the anchoring tissue in a wide range of orientations and is not strictly limited to the orientations shown in FIGS. 12F-12G.

[0194] In some such examples, the anchoring tissue 720 may comprise a large region 723 (e.g., muscle belly) against which the convex second face portion 706 may face and be pressingly engaged as shown in FIGS. 12F-12G. In this example, the “anchoring” tissue (against which the second face portion 706 of housing 702 is pressingly engaged) comprises a surface area substantially greater than (e.g., 25% greater, 50% greater, 75% greater, etc.) a surface area of the second face portion 706 of housing 704.

[0195] As further shown in FIG. 12G, with second face portion 706 pressingly engaging portion 724 of anchoring tissue 720, anchor wing portions 710a, 710b of IMD 700 are secured relative to anchoring tissue 720 at regions 727 of tissue 720 via one or more sutures 727 (which provide pulling forces F1), which in turn may cause the convex second face portion 706 to form a shallow recessed pocket 725 at portion 724 of anchoring tissue 720, with portion 724 partially wrapping about the respective opposite ends 709A, 709B of the second face portion 706 of housing 702. In some examples, the pocket 725 at portion 724 of anchoring tissue 720 may comprise a depth D1 which may generally correspond to a height H4 of convex second face portion 706 which protrudes upward from the face portion 716 of anchor wing portions 710a, 710b of housing 702. It will be understood that in a similar manner, the portion 724 of tissue 720 defining pocket 725 may partially wrap about sides 708a, 708b (FIG. 12F) of the second face portion 706 of housing 702 of IMD 700.

[0196] As further shown in FIG. 12G, regions 723 of anchoring tissue 720 which extend laterally of anchor wing portions 710a, 710b (of housing 702 of IMD 700) may extend in a plane P which is generally parallel to and / or aligned with the anchor wing portions 710a, 710b. In some examples, in its implanted state shown in FIG. 12G, the generally arcuate shape of the first face portion 704 (which may be contiguous with the arcuate shape of bottom face portion 714 of anchor wing portions 710a, 710b) may generally be aligned with a plane P which portion 723 of anchoring tissue 720 extends such that the first face portion 704 of housing 702 generally blends in with and / or among the layers of tissues (e.g., other muscles, fascia, tendons, etc.) which may overlie the anchoring tissue 720. In at least this way, the housing 702 is adapted to minimize impact of the implanted housing 702 on function(s) of other tissues adjacent the anchoring tissue 720.

[0197] In one aspect, the general convexity of second face portion 706 provides a shape and size (e.g., surface area) adapted to press inward on the anchoring tissue 720 to at least partially impress at least a portion of the second face portion 706 into the portion 724 of anchoring tissue 720. Among other aspects, this example implementation may provide greater resistance to movement of the housing 702 of IMD 700 relative to the anchoring tissue 720. In this way, in combination with the sutures 727 fixing anchor wing portions (e.g., 710a, 710b) at regions 728 of anchoring tissue 720, the pocket-forming size and / or shape of the convex second face portion 706 significantly contributes to fixating the housing 702 in a stable position relative to anchoring tissue 720.

[0198] In some examples, the anchoring tissue 720 may include a mylohyoid muscle for anchoring the housing 702 of the IMD 700, where in some examples the housing 702 may support a stimulation lead to apply electrical stimulation via the IMD 700 to a hypoglossal nerve and / or the housing 702 may support a sensing lead.

[0199] In some examples, the anchoring tissue 720 may comprise a sternocleidomastoid (SCM) muscle with the housing 702 of the IMD 700 supporting a sensing lead and / or a stimulation lead (e.g., 674 in FIGS. 11A-11D) to apply electrical stimulation via the IMD 700 to an internal superior laryngeal nerve, an infrahyoid muscle (IHM)-innervating nerve, a phrenic nerve, and / or other nerve. In some such examples, the anchoring tissue 720 comprises an inferior portion of the SCM muscle, such as portions of the of the SCM muscle which are inferior to the omohyoid muscle. Anchoring the housing 702 of IMD 700 to such portions of the SCM muscle may facilitate access and implantation of IMDs in reasonably close proximity to the clavicle, which may be suitable for placing leads in sensing relation and / or stimulating relation to an infrahyoid muscle (IHM)-innervating nerve, phrenic nerve, etc.

[0200] It will be understood that the anchoring tissue 720 (against which the convex second face portion 706 of housing 702 faces and pressingly engages) may comprise non-muscular tissues in some examples. Moreover, in further examples, the convex second face portion 706 of housing 702 may be sized and / or shaped to correspond to, and pressingly engage, a contour (e.g., recesses, protrusions, etc.) of a bony structure which acts as an anchoring tissue for IMD 700.

[0201] In some examples, the anchoring tissue 720 (against which the convex second face portion 706 pressingly engages) may comprise a portion of the mylohyoid muscle at which the housing 702 will become positioned laterally, superiorly, inferiorly, etc. relative to the digastric muscle / tendon such that the housing 702 is not positioned between the mylohyoid muscle and the digastric muscle (e.g., anterior portion or posterior portion). Stated differently, the housing 702 of IMD 700 may comprise shape(s) and / or otherfeatures conducive to anchoring such that the housing 702 can be placed at various locations of an anchoring tissue without being constrained by having to be located between two anchoring tissues (e.g., mylohyoid muscle and digastric muscle).

[0202] However, in some examples, the housing 702 of IMD 700 may be positioned in a fixed location between the mylohyoid muscle and the digastric muscle (e.g., either the anterior portion or the posterior portion thereof).

[0203] In some examples, the anchoring tissue may comprise other large surface area muscles such as a sternothyroid muscle, sternohyoid muscle, and the like. In some such examples, these anchoring tissues also may comprise a target tissue for sensing and / or electrical stimulation. For instance, in at least some such examples, the housing 702 may support a surface electrode for stimulating a muscle that the housing 702 is in contact against (with muscle acting as anchoring tissue) and / or may support a lead including a stimulation electrode to contact the same muscle and / or to contact a nerve that innervates the same muscle. In some examples, such contact by the stimulation electrode will be understood to include contact with nerve motor points at neuromuscular junction of the muscle and nerve innervating said muscle.

[0204] In some examples, the housing 702 of IMD 700 may be positioned in a fixed location between the two different infrahyoid strap muscles such as (but not limited to) the sternothyroid muscle and the sternothyroid muscle.

[0205] FIG. 12H is a top view of a second face portion 706 of an example housing (e.g., housing 702) of an IMD 700 which includes an array 729 of electrodes 729a exposed on second face portion 706 (e.g., on its exterior surface) of the housing 702. In some examples, the example arrangement of FIG. 12H may comprise at least some of substantially the same features as, and / or an example implementation of, the examples of FIGS. 1A-12G and 13A-33. In some examples, the electrodes 729a may be used for delivering a stimulation signal and / or for sensing. The spaced apart electrodes 729a are independently controllable and may be activated separately or in select groupings. In some examples, the various stimulation vectors may be applied via the select groupings of electrodes 729a and / or via activation of one or more of electrodes 729a with other electrode(s) located elsewhere (e.g., on a lead).

[0206] FIG. 121 is a sectional side view illustrating at least the exposed electrodes 729a of second face portion 706 (of housing 702 of FIG. 12H) in stimulating relation (and / or sensing relation) to portion 724 of anchoring tissue 720. As seen in FIG. 121, the previously described generally convex shape of second face portion 706 and / or anchoring via anchor wings 710a, 710b may facilitate engagement of the electrodes 729a against portion 724 of anchoring tissue 720.

[0207] It will be understood that the array 729 may comprise a greater number or lesser number of electrodes 729a than shown in FIGS. 12H-12I, and that at least 57 some of the electrodes 729a may be located on any one or more of the various segments 706a-706d in addition to, or instead of, segment 706e (i.e., central portion). In some examples, at least one electrode 729a may be located on first face portion 704, whether or not at least one electrode 729a is present on second face portion 706.

[0208] Moreover, it will be understood that at least some of the example IMDs of at least FIGS. 1A-11D and 13A-22B may comprise the features associated with electrodes 729a of FIGS. 12H-12L

[0209] FIGS. 13A-13E are various views schematically representing an example IMD 730. FIG. 13A is a bottom view, FIG. 13B is a top view, FIG. 13C is a front view, FIG. 13D is a side view, and FIG. 13E is an isometric view of the IMD 730. The IMD 730 may comprise at least some of substantially the same features as, and / or an example implementation of at least some of the features of, the various examples of at least FIGS. 1A-11D and 23A-33.

[0210] The IMD 730 includes a housing 732, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 732 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). The wireless communication portion 303 may comprise a receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C).

[0211] In some examples, the IMD 730 may comprise one or more leads (e.g., 674 in FIGS. 11A-11D) electrically connected to at least some of the various elements within housing 732 of IMD 730, with such lead(s) carrying a stimulation electrode and / or sensing element, or other functional element.

[0212] In some examples, the housing 732 includes a concave face portion 734 (e.g., bottom face or outer wall), a convex face portion 736 (e.g., top and sides faces) opposite to the concave face portion 734, a first end face portion 738a, and a second end face portion 738b opposite to the first end face portion 738a. In some examples, the housing 732 may further comprise a first suture trench 740a arranged on a surface (e.g., on convex face portion 736) of the housing 732, and a second suture trench 740b arranged on the surface of the housing 732 opposite to the first suture trench 740a. The first suture trench 740a is for fixation of the housing 732 within a patient via at least one first suture (e.g., wrapped around patient tissue and the suture trench 740a of the housing 732), and the second suture trench 740b is for fixation of the housing 732 within the patient via at least one second suture (e.g., wrapped around patient tissue and the suture trench 740b of the housing 732). The first suture trench 740a may be arranged at a distance 754 (FIG. 13B) from the first end face portion 738a, and the second suture trench 740b may be arranged at the distance 754 from the second end face portion 738b. In some examples, the distance 754 is greater than or equal to one-sixteenth of the length 750 and less than or equal to one-third of the length 750. In some examples, the housing 732 may include further suture trenches (not shown) (e.g., 3, 4, or more) or only one suture trench centered between the first end face portion 738a and the second end face portion 738b.

[0213] The concave face portion 734 is coupled to (e.g., integral to, adhered to, welded to) the convex face portion 736, the first end face portion 738a, and the second end face portion 738b to form an enclosure having a length 750, a width 752 (FIG. 13A), and a height 756 (FIG. 13C). In some examples, the length 750 is greater than the width 752, and the width 752 is greater than the height 756. In some examples, the length 750 is at least 1.5 times, 2 times, 3 times, or 4 times the width 752. In some examples, the length 750 may be less than or equal to the width 752, and / or the width 752 may be less than or equal to the height 756. In some examples, the length 750 may be less than or equal to 4 centimeters, the width 752 may be less than or equal to 2 centimeters, and the height 756 may be less than or equal to 2 centimeters. 59

[0214] As best illustrated in FIG. 13C, in some examples the concave face portion 734 is a smooth and continuous concave face portion (e.g., including a continuous curve across the width 752 of the enclosure that is the same along the entire length 750 of the enclosure). In some examples, the face portion 734 may include at least one undulating region such that the entire face portion 734 is not concave.

[0215] As best illustrated in FIGS. 13B, 13C, and 13E, in some examples the convex face portion 736 may include segments 736a-736c. The segments 736a-736c include a convex first segment 736a, a convex second segment 736b, and a planar third segment 736c. The convex first segment 736a is opposite to the convex second segment 736b. The planar third segment 736c extends between and connects the convex first segment 736a and the convex second segment 736b between the first end face portion 738a and the second end face portion 738b. While the face portion 736 is generally described as a convex element, it will be understood that the face portion 736 may sometimes be referred to as being partially convex based on the convexity of side segments 736a, 736b and / or may sometimes by referred to as being partially planar based on the planar segment 736c. Moreover, in some examples, the planar third segment 736c may comprise an arcuate shape, which may be convex or concave in order to facilitate maneuverability and / or chronic implantation within and among bodily tissues.

[0216] As further shown in FIGS. 13A-13E, the convex first segment 736a is coupled to a first side of the concave face portion 734 and extends between the first end face portion 738a and the second end face portion 738b. The convex second segment 736c is coupled to a second side of the concave face portion 734 and extends between the first end face portion 738a and the second end face portion 738b. Via the foregoing arrangement, the housing 732 may comprise a prong 735 (FIG. 13C) formed at a junction of the segment 736a and concave face portion 734, and a prong 735 formed at a junction of the segment 736b and concave face portion 734.

[0217] As best illustrated in FIGS. 13B, 13D, and 13E, the first suture trench 740a and the second suture trench 740b may include semicircular channels, grooves, or elongated recesses or indentations extending into the surface of the convex face portion 736 across the width of the convex face portion 736 from a first side of the concave face portion 734 to a second side of the concave face portion 734 opposite to the first side in a direction parallel to the first end face portion 738a and the second end face portion 738b. In some examples, the first suture trench 740a and the second suture trench 740b may include channels, grooves, or elongated recesses or indentations having another suitable shape, such as rectangular, triangular, trapezoidal, etc. A maximum depth of each suture trench 740a and 740b (e.g., at the center of each suture trench) may be within a range between 1 millimeter and 5 millimeters, and a width of each suture trench 740a and 740b may be within a range between 0.5 millimeters and 5 millimeters.

[0218] In some examples, the housing 732 is configured for fixation to an anchoring tissue 745 as shown in FIG. 13F. In some examples, the anchoring tissue 745 may comprise a tendon or a narrow muscle belly (e.g., with the concave face portion 734 facing the tendon or narrow muscle belly).

[0219] FIG. 13F is a top view schematically representing housing 732 in pressing engagement relative to anchoring tissue 745. In particular, housing 732 is oriented to align concave face portion 734 with an outer surface 746 of anchoring tissue 745 in which the size (e.g., depth H6, width W4) and arcuate shape of the concave face portion 734 generally corresponds to a size and arcuate shape of the convex outer surface 746 of anchoring tissue 745. As further shown in FIG. 13F, a suture 748 may be positioned to extend within and through trench 740a (also representative for trench 740b), as well as circumferentially about surface 746 of anchoring tissue 745 to urge the concave face portion 734 into pressing engagement relative to the anchoring tissue 745.

[0220] In some examples, the anchoring tissue 745 may comprise a tendon or narrow muscle belly such as (but not limited to) a digastric tendon to anchor housing 732 to support a lead for applying electrical stimulation via the IMD 730 to a hypoglossal nerve. In some examples, the anchoring tissue 745 may comprise an omohyoid muscle to anchor housing 732 to support a lead for applying electrical 61 stimulation via the IMD 730 to an infrahyoid muscle (IHM)-innervating nerve and / or a phrenic nerve, or other nerves.

[0221] As shown in FIG. 13G, in some examples an IMD 750 may comprise at least some of substantially the same features as IMD 730, except comprise diagonal trenches 753a, 753b which may be provided in addition to trenches 740a, 740b or instead of trenches 740a, 740b. In some instances, trenches 753a, 753b may intersect with trenches 740a, 740b in order to facilitate dual use of the trenches 753a, 753b with trenches 740a, 740b.

[0222] FIGS. 14A-14E are various views schematically representing an example IMD 760. FIG. 14A is an isometric view of the IMD 760 while FIG. 14B is a bottom view, FIG. 14C is a top view, FIG. 14D is a front view, FIG. 14E is a side view of the IMD 760. The IMD 760 may comprise at least some of substantially the same features as, and / or an example implementation of at least some of the features of, the various examples of at least FIGS. 1A-13E and 23A-33.

[0223] The IMD 760 includes a housing 762, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as (but not limited to) sensors (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 762 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). The wireless communication portion 303 may comprise a receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C). In some examples, the IMD 760 may comprise one or more leads (e.g., 674 in FIGS. 11A-11D) electrically connected to at least some of the various elements within housing 762 of IMD 760, with such lead(s) carrying a stimulation electrode and / or sensing element, or other functional element.

[0224] As shown in FIGS. 14A-14E, the housing 762 may include a first face portion 764 (e.g., bottom face or outer wall), a second face portion 766 (e.g., top face or outer wall) opposite to the first face portion 764, and four sidewalls 767a-676d coupled between the first face portion 764 and the second face portion 766. In some such examples, the portion of the housing 762 defined by portion 764, 766, and four sidewalls 767a-767d define an enclosure 762a (e.g., sealed hollow interior for containing elements).

[0225] In some examples, the housing 762 further includes a first anchor wing 770a coupled to a first side of the convex face portion 764, a second anchor wing 770b coupled to a second side of the convex face portion 764 opposite to the first side, a third anchor wing 770c coupled to a third side of the convex face portion 764 extending between the first side and the second side, and a fourth anchor wing 770d coupled to a fourth side of the convex face portion 764 opposite to the third side. Accordingly, in some such examples, the anchor wings may sometimes be referred to as extending outward from the sidewalls of the enclosure 762a of the housing 762.

[0226] The first anchor wing 770a is for fixation of the housing 762 within a patient via at least one first fastener, the second anchor wing 770b is for fixation of the housing 762 within the patient via at least one second fastener, the third anchor wing 770c is for fixation of the housing 762 within the patient via at least one third fastener, and the fourth anchor wing 770d is for fixation of the housing 762 within the patient via at least one fourth fastener. In some examples, the housing 762 may include less than four anchor wings, such as two anchor wings on opposing sides of the housing 762. In these examples, the anchor wings 770a and 770b may be excluded or the anchor wings 770c and 770d may be excluded. In some examples, the respective fasteners may comprise screws and / or other elements suitable for fixation into a bony structure or other rugged structures within the body. In some examples, at least some of the fasteners may comprise a suture.

[0227] The first face portion 764 is coupled to (e.g., integral to, adhered to, welded to) sidewalls 767a-767d, which are coupled to (e.g., integral to, adhered to, welded to) the second face portion 766 to form an enclosure 762a having a length L5, a width W6 (FIG. 14C), and a maximum height H6 (FIG. 14D). In some examples, the length L5 is greater than the width W6, and the width W6 is greater than the maximum height H6. In some examples, the length L5 is at least 1.5 times, 2 times, 3 times, or 4 times the width W6. In some examples, the length L5 may be less than or equal to the width W6, and / or the width W6 may be less than or equal to the maximum height H6.

[0228] In some examples, the first face portion 764 may comprise an arcuate shape / surface. In some examples, the second face portion 766 may comprise a generally arcuate shape adapted to correspond to a surface topography of an anchoring tissue of the body against which at least a portion of the second face portion 766 will be releasably engaged while anchor wings (770a, 770b, 770b, 770d) facilitate use of fasteners to secure the housing 762 relative to the anchoring tissue.

[0229] With this in mind, in some examples, the generally arcuate shape of second face portion 766 comprises a convex portion, such as defined by a convex ridge portion 765 extending generally parallel to a major axis of the housing 762 with ridge portion 765 extending between opposite segments 767a, 767b (e.g., opposite ends). As shown in FIG. 14E, the convex ridge portion 765 comprises a central ridge portion 765c extending between end ridge portions 765a, 765b.

[0230] In addition to the convex ridge portion 765, in some examples the generally arcuate shape of second face portion 766 comprises at least one concave portion such as (but not limited to) concave portions 768a (represented by dashed lines 769a), 768b (represented by dashed lines 769b) located on opposite sides of the convex ridge portion 765. In some such examples, the combination of the convex ridge portion 765 and the concave side portions 768a, 768b may form a saddle shape in which a generally smooth transition takes place via the concave side portion 768a, 768b extending outward seamlessly from the more centrally located ridge portion 765. In some examples, at least some aspects of this relationship (which form the saddle shape) may be represented via contour line 761 in which a central portion 761c of contour line 761 is located along or at the central ridge portion 765c and 64 opposite end portions 761a, 761b of contour line 761 terminate at side segments 767c, 767d.

[0231] As further shown in at least FIGS. 14A, 14C, and 14E, in some examples each end ridge portion 765a, 765b (of second face portion 766) forms part of a respective end convex portion 763a, 763b, respectively, which may further define the saddle shape of second face portion 766.

[0232] In some examples, the combination of the convexities and concavities of the second face portion 766 may facilitate releasable fixation (e.g., anchoring) of the housing 762 relative to an anchoring tissue, as further described below in association with at least FIGS. 14F-14G.

[0233] As best illustrated in FIGS. 14A and 14C, sidewalls 767a-767d include a first sidewall 767a, a second sidewall 767b, a third sidewall 767c, and a fourth sidewall 767d. The first sidewall 767a is opposite to the second sidewall 767b, and the third sidewall 767c is opposite to the fourth sidewall 767d. The first sidewall 767a and the second sidewall 767b each extend between the third sidewall 767c and the fourth sidewall 767d. The first sidewall 767a is adjacent to the first anchor wing 770a, the second sidewall 767b is adjacent to the second anchor wing 770b, the third sidewall 767c is adjacent to the third anchor wing 770c, and the fourth sidewall 767d is adjacent to the fourth anchor wing 770d. The second face portion 766 extends between and connects the first sidewall 767a, the second sidewall 767b, the third sidewall 767c, and the fourth sidewall 767d. The edges where each of the first sidewall 767a, the second sidewall 767b, the third sidewall 767c, and the fourth sidewall 767d connect to the second face portion 766 may be rounded.

[0234] As best illustrated in FIGS. 14B and 14C, the first anchor wing 770a and the second anchor wing 770b may include trapezoidal shaped structures protruding from opposing sidewalls 767a and 767b, respectively, of the enclosure including the arcuate shaped (e.g., saddle shaped) second face portion 766. Each of the respective first anchor wing 770a and the second anchor wing 770b may have a maximum length equal to or less than the width W6 of the enclosure and may have a maximum width W7. In some examples, the first anchor wing 770a and the second anchor wing 770b may include structures having another suitable shape, such as triangular, rectangular, half circular, etc., protruding from opposing sidewalls 767a and 767b, respectively, of the saddle-shaped enclosure. The third anchor wing 770c and the fourth anchor wing 770d may include triangular shaped structures protruding from opposing sidewalls 767c and 767d, respectively, of the saddle-shaped enclosure. Each respective third anchor wing 770c and fourth anchor wing 770d may have a maximum length equal to or less than the length L5 of the enclosure and may have a maximum width W8. In some examples, the maximum width W8 may be equal to the maximum width W7. In some examples, the maximum width W8 may be different from the maximum width W7. In some examples, the third anchor wing 770c and the fourth anchor wing 770d may include structures having another suitable shape, such as trapezoidal, rectangular, half circular, etc., protruding from opposing sidewalls 767c and 767d, respectively, of the arcuate shaped (e.g., saddle shaped) enclosure of the housing 762. In some examples as best illustrated in FIGS. 14A, 14B, and 14C, each anchor wing 770a-770d may be integral to (e.g., form a single unitary structure with or be monolithic with) the first face portion 764 and include a bottom face corresponding to the convex shape of the first face portion 764. In some examples, the length L5 of the enclosure 762a plus two times the maximum width W7 of the anchor wings 770a and 770b provides an overall length of the housing 762 of less than or equal to 4 centimeters. In some examples, the width W6 of the enclosure 762a plus two times the maximum width W8 of the anchor wings 770c and 770d provide an overall width of the housing 762 of less than or equal to 2 centimeters. In some examples, the maximum height H6 (FIG. 14D) of the housing 762 is less than or equal to 2 centimeters.

[0235] Each anchor wing 770a and 770d includes one through hole 772a (e.g., fastener anchor point) extending through the center of each anchor wing 770a and 770d, and each anchor wing 770b and 770c includes one through hole 772b (e.g., fastener anchor point) extending through the center of each anchor wing 770b and 770c. While through holes 772a illustrated in FIGS. 14A and 14B are circular in shape, in some examples, through holes 772a may have another suitable shape, such as oval, rectangular, hexagonal, etc. While through holes 772b illustrated in FIGS. 14A and 14B are oval in shape, in some examples, through holes 772b may have another suitable shape, such as circular, rectangular, hexagonal, etc. In some examples, each anchor wing 770a-770d may include more than one through hole 772a or 772b, such as two through holes on opposing sides of each anchor wing 770a-770d. In some examples, the greatest cross-sectional dimension of each through hole 772a and / or 772b is less than or equal to 5 millimeters. In some examples, the greatest cross-sectional dimension of each through hole 772a and / or 772b is greater than 5 millimeters.

[0236] In some examples, the housing 762 of IMD 760 is configured for fixation to an anchoring tissue 790, such as schematically represented in at least FIGS. 14F-14H.

[0237] FIG. 14F is a diagram including a partial sectional view schematically representing the housing 762 of the IMD 760 securely engaging an anchoring tissue 790a (represented via section lines) with at least second face portion 766 pressingly engaging a surface 791 of the anchoring tissue 790a, and anchor wings 770c and 770d supporting fasteners F1, F2 to engage portions 793a, 793b of the anchoring tissue to pull (and maintain) the second face portion 766 into engagement (e.g., contact) against the surface 791 of the anchoring tissue 790a. In some examples, the arrangement shown in FIG. 14F may comprise a sectional view as taken along lines 14F—14F in FIG. 14G, which is further described later.

[0238] Via this arrangement, as further shown in FIG. 14F, in some such examples the central portion 765c of the major convex ridge portion 765 and the minor ridge portion 761 c (which extends transverse to the major convex ridge portion 765) of the second face portion 766 of housing 762 together engage a recessed (e.g., concave) surface portion 791c of the anchoring tissue 790a, while recessed portions 761a, 761b (e.g., concave portions 768a, 768b) of face portion 766 engaging protruding surface portions 791a, 791b (e.g., convex portions) of the anchoring tissue 790a, respectively.

[0239] In some examples, the second face portion 766 of housing 762 comprises a juxtaposition of a generally convex portion (e.g., the combination of the major ridge portion 765c and minor ridge portion 761c) with a generally concave portion (768a or 768b, as partially represented by concave contour line 761a or 761b). In some such examples, an inflection portion defines a smooth transition between the respective generally convex portion (e.g., the combination of the major ridge portion 765c and minor ridge portion 761c) and concave portion (e.g., 768a or 768b). In some examples, the above-mentioned generally convex portion is interposed between a pair of concave portions (e.g., 768a, 768b) on opposite sides of the generally convex portion.

[0240] Among other aspects, the general correspondence of a size / shape of the convex portion(s) (e.g., combination of major ridge portion 765c and minor ridge portion 761c) of the second face portion 766 (of housing 762) with a size / shape of the concave recessed portions (e.g., 791c) of the anchoring tissue 790a, along with a general correspondence of the size / shape of the concave portions (e.g., 768a, 768b) of the second face portion 766 (of housing 762) with convex protruding portions (e.g., 791a, 791b) acts to significantly hinder movement (lateral or longitudinal) of housing 762 relative to the surface 791 of anchoring tissue 790a. This arrangement, in combination with the action of fasteners F1, F2 pulling anchor wings 770c, 770d (and therefore the entire first face portion 764 and housing 762) inward toward the surface 791 of the anchoring tissue, acts to robustly secure the housing 762 relative to the anchoring tissue.

[0241] In addition to generally securing the housing 762 relative to the anchoring tissue 790a, the highly engaged (e.g., interlocking, nesting, etc.) relationship of the convexities and concavities of the second face portion 766 with the convexities and concavities of the surface 791 of the anchoring tissue 790a may significantly facilitate precision sensing such as when the housing 762 contains a sensing element and the sensing element may sense movement such as (but not limited to) indicative to respiration (including respiratory phase information). For instance, one example sensing element mounted according to the example of FIGS. 14A-14H may comprise an accelerometer (e.g., three-axis accelerometer) to perform such sensing. Among other locations, one such example utilizes a mandible as the anchoring tissue (790a) to enable an accelerometer within a housing 762 to reliably and accurately sense movement associated with respiration. Accordingly, the high anchoring stability afforded by the topographic profile (e.g., juxtaposed convexities and concavities, such as (but not limited to) a saddle shape) of second face portion 766 may provide for the sensor accuracy and precision appropriate to sense respiratory-indicative movements suitable to determine respiratory phase information and / or other respiratory information.

[0242] In some examples, the topographic profile of the second face portion 766 of housing 762 is also suitable for securely engaging other anchoring tissues, whether in the head-and-neck region or in other regions of the body for sensing respiration and / or other parameters.

[0243] FIG. 14G also provides a schematic representation of engagement of second face portion 766 of housing 762 against anchoring tissue 790b. In some such examples, the arrangement shown in FIG. 14G may comprise a sectional view as taken along lines 14G—14G of previously described FIG. 14F such that the anchoring tissue 790b may generally correspond to anchoring tissue 790a in FIG. 14, except seen from an orientation transverse to that shown in FIG. 14F.

[0244] As shown in FIG. 14G, in some examples housing 762 of IMD 760 securely engages anchoring tissue 790b (represented via section lines) with at least second face portion 766 pressingly engaging a surface 797 of the anchoring tissue 790a, and anchor wings 770a, 770b supporting fasteners F3, F4 to engage portions 796a, 796b of the anchoring tissue to pull (and maintain) the second face portion 766 into engagement (e.g., contact) against the surface 797 of the anchoring tissue 790b. In some examples, the arrangement shown in FIG. 14G may be implemented simultaneously with the arrangement shown in FIG. 14F via a single housing 762 of an IMD 760. It will be understood, however, that in some examples the arrangement in FIG. 14F may comprise an example implementation independent of the arrangement in FIG. 14G.

[0245] With further reference to FIG. 14G, among other aspects, in some examples at least one segment of the major ridge portion 765 of second face portion 766 of housing 762 engages against at least one segment of the recessed (e.g., concave) surface portion 797 of anchoring tissue 790b to firmly seat the second face portion 766 relative to the anchoring tissue 790b. In some such examples, a majority of the major ridge portion 765 (including portions 765a, 765b, and / or 765c) of second face portion 766 of housing 762 engages a majority of the recessed surface portion 797 (including portions 797a, 797b, and / or 797c) of anchoring tissue 790b. In some examples, substantially the entire major ridge portion 765 (including portions 765a, 765b, 765c) of second face portion 766 of housing 762 engages substantially the entire recessed surface portion 797 (including portions 797a, 797b, 797c) of anchoring tissue 790b.

[0246] It will be understood that each of the various concave portions and convex portion of a given second face portion 766 of housing 762 need not correspond directly with each and every available concavity and / or convexity of a surface portion of a particular anchoring tissue (e.g., bony structure, in some examples). With this in mind, FIG. 14H schematically represents an arrangement comprising at least some of substantially the same features as for the example of FIG. 14F, except with the anchoring tissue 790c comprising a surface portion 795 which includes a portion 795b which does not correspond to the size / shape of the minor ridge portion 761c and concave portion 761b. Despite this lack of engagement for part of the second face portion 766 (relative to surface portion 795 of anchoring tissue 790c), the remaining main ridge portion 765c and minor ridge portion 761 c, and concave portion 761a which do engage corresponding portions 795c, 795a of anchoring tissue 790c may provide sufficient interaction (e.g., seating) to robustly engage (e.g., prevent undesired migration, translation, etc.) the housing 762 against the anchoring tissue 790c, simultaneous with the action of fasteners F1, F2 and anchor wings 770c, 770d to achieve secure fixation of the housing 762 relative to portions 799a, 799b of the anchoring tissue 790c.

[0247] Among other possible uses of an IMD 760 robustly secured relative to anchoring tissue 790a, the IMD 760 may comprise a stimulation lead connected to and extending from the housing 762 for applying electrical stimulation to a target tissue such as a nerve and / or muscle. In some examples, the anchoring tissue 790a may comprise a mandible and the target tissue may comprise an upper airway patency-related nerve (or muscle) such as the hypoglossal nerve and / or infrahyoid muscle (IHM)-innervating nerve, wherein electrical stimulation of these tissues may treat sleep disordered breathing (SDB) such as obstructive sleep apnea.

[0248] In some examples, the various convexities and concavities (or combination thereof) may be used to engage anchoring tissue which comprises a juxtaposition of two different tissues (e.g., a tendon juxtaposed with bone, tendon juxtaposed with muscle, bone juxtaposed with bone, etc.) in which a convexity (e.g., ridge portion 765) may fit within a gap or angle formed by the different tissues and / or in which a concavity (e.g., 768a, 768b) of second face portion 766 may receive one of two juxtaposed tissues which forms a protrusion relative to other / respective portions of the anchoring tissue.

[0249] In some examples, the various convexities and / or concavities of a second face portion 766 may have different sizes and may have irregular spacing therebetween. In some examples, the various convexities and / or concavities may provide a second face portion 766 which is asymmetric in its topography for engaging a surface portion of an anchoring tissue. In some examples, the quantity of the various convexities and / or concavities of second face portion 766 may be sufficient to provide a generally dimpled surface (which may or may not have uniform sizing and / or spacing) to engage a surface portion of an anchoring tissue.

[0250] In some examples, the housing 762 may be sized and / or shaped according to the above-described example parameters associated with at least FIGS. 14A-14H in order to securely engage other rigid or semi-rigid structures (e.g., hyoid bone, thyroid cartilage, clavicle, etc.) such as at least some of those example tissues described in association with at least FIG. 1DD.

[0251] In some examples, the housing 762 may be sized and / or shaped according to the above-described example parameters associated with at least FIGS. 14A-14H in order to securely engage non-rigid structures (e.g., muscles, soft non-nerve tissues, etc.) such as at least some of those example tissues (e.g., SCM muscle, omohyoid muscle) described in association with at least FIG. 12A-12G in situations in which a juxtaposition of convexities (e.g., protrusions) and concavities (recesses) of a second face portion 766 of housing 762 may reasonably correspond with a juxtaposition of convexities and concavities of an anchoring region (i.e., anchoring tissue) formed from one or more different bodily tissues.

[0252] FIGS. 15A-15E are various views schematically representing an example IMD 800. FIG. 15A is an isometric view of the IMD 800, while FIG. 15B is a bottom view, FIG. 15C is a top view, FIG. 15D is a front view, and FIG. 15E is a side view. In some examples, the IMD 800 comprises at least some of substantially the same features as, and / or an example implementation of at least some of the features of, the examples associated with at least FIGS. 14A-14H, except with through holes 812 of IMD 800 being formed within a portion of the housing 802 (partially defined by sidewalls 807a-807d) instead of being defined within anchor wings (e.g., 710a, 710b in FIGS. 12A-12G) which extend outward from ends (e.g., 709a, 709b) and / or sides (e.g., 708a, 708b) of a housing (e.g., 702 in FIGS. 12A-12G), among other differences noted below.

[0253] In some examples, the IMD 800 includes a housing 802, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 802 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). In some examples, the wireless communication portion 303 comprises a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication 72 element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C),

[0254] As further shown in FIGS. 15A-15E, the housing 802 includes a convex first face portion 804 (e.g., bottom face or first outer wall), a second face portion 806 (e.g., top face or second outer wall) opposite to the first face portion 804, and four sidewalls 807a-807d coupled between the first face portion 804 and the second face portion 806. In some examples, the second face portion 806 includes a planar first segment 806a, a planar second segment 806b opposite to the planar first segment 806a, and an arcuate third segment 806c extending between and connecting the planar first segment 806a and the planar second segment 806b. In some examples, the arcuate third segment 806c of the second face portion 806 comprises at least some of substantially the same features as the arcuate second face portion 766 of housing 762 of IMD 760 in FIGS. 14A-14H. For example, as shown in FIGS. 15A-15G, second face portion 806 comprises a major ridge portion 815 (like ridge portion 765 in FIGS. 14A-14H) including portions 815a, 815b, 815c, and a minor ridge portion 821 (like portion 761 in FIGS. 14A-14H) including portions 821a, 821b, 821c, which thereby define a convex portion (defined by portions 815c, 821c) and optional concave portions 828a (represented by dashed lines 829a), 828b (represented by dashed lines 829b) (like portions 768a, 768b in FIGS. 14A-14H).

[0255] However, unlike the housing 762 of IMD 760 in FIGS. 14A-14H, the housing 802 of IMD 800 in FIGS. 15A-15G further comprises the planar segments 806a, 806b on opposite ends of the central arcuate third segment 806c which are adapted for engagement against anchoring tissue as further described in association with at least FIGS. 15F-15G. Moreover, in some examples, one or both of the planar segments 806a, 806b may comprise at least one protrusion (e.g., convexity) and / or at least one recess (e.g., concavity) according to at least some of the various example parameters of second face portion 766 of FIGS. 14A-14H. Moreover, as shown in FIG. 15E, in some examples, one or both of the planar segments 806a, 806b may be formed to extend (along a plane represented by dashed line P1) at an angle (alpha a) relative to a neutral plane N. In this example, the planar segments 806a, 806b tend to slope away from the opposite ends of the central arcuate segment 806c. However, in some examples, one or both the planar segments 806a, 806b may extend along (e.g., through) the neutral plane N or may extend (along a plane represented by dashed line P2) at an angle (omicron Q) relative to the neutral plane N. In some examples, one planar segment 806a, 806b may extend at an angle along plane PI (e.g., a more open orientation relative to central segment 806c) while the other respective planar segment 806a, 806b may extend at an angle along plane P2 (e.g., a more closed orientation relative to central segment 806c). In some examples, the angle alpha (a) may fall within a range of about 0 and about 45 degrees, while the angle omicron (Q) for plane P2 may be within a range of about 0 and about 45 degrees. The particular angle at which planar segments 806a, 806b extend relative to the neutral plane N may be selected (during formation of housing 802) such that the particular angles may enhance fixation of the housing 802 relative to the applicable anchoring tissue to which the housing 802 will be fixated upon application of fasteners (e.g., F3, F4, F5, etc.) via through holes 812.

[0256] The first face portion 804 is coupled to (e.g., integral to, adhered to, welded to) sidewalls 807a-806d, which are coupled to (e.g., are integral to, adhered to, welded to) the second face portion 806 to form an enclosure 802a having a length 811, a width 813 (FIG. 15B), and a maximum height 814 (FIG. 15E). In some examples, the length 811 is greater than the width 813, and the width 813 is greater than the maximum height 814. In some examples, the length 811 is at least 1.5 times, 2 times, 3 times, or 4 times the width 813. In some examples, the length 811 may be less than or equal to the width 813, and / or the width 813 may be less than or equal to the maximum height 814. In some examples, the length 811 may be less than or equal to 4 centimeters, the width 813 may be less than or equal to 2 centimeters, and the maximum height 814 may be less than or equal to 2 centimeters.

[0257] As best illustrated in FIGS. 15A and 15C, the sidewalls 807a-807d include a first sidewall 807a, a second sidewall 807b, a third sidewall 807c, and a fourth sidewall 807d. The first sidewall 807a is opposite to the second sidewall 807b, and the third sidewall 807c is opposite to the fourth sidewall 807d. The first sidewall 807a and the second sidewall 807b each extend between the third sidewall 807c and the fourth sidewall 807d. The first face portion 804 and the second face portion 806 each extend between and connect the first sidewall 807a, the second sidewall 807b, the third sidewall 807c, and the fourth sidewall 807d. The edges where each of the first sidewall 807a, the second sidewall 807b, the third sidewall 807c, and the fourth sidewall 807d connect to the first face portion 804 and the second face portion 806 may be rounded.

[0258] In some examples, the housing 802 further includes four through holes 812 (e.g., screw or suture anchor points) extending through the housing 802 including through the first face portion 804 and the second face portion 806 (e.g., through first segment 806a and second segment 806b). In this example, each through hole 812 extends through the first face portion 804 and the second face portion 806 adjacent to a corner of the housing 802. Each through hole 812 may be for fixation of the housing 802 within a patient via a screw or other fastener, such that in this example four screws may be used to fix the housing 802 within a patient. In some examples, the housing 802 may include less than fourthrough holes 812, such as one through hole through the center of the housing 802, two through holes on opposing sides of the housing 802, or three through holes arranged through the housing 802. In some examples, the housing 802 may include more than four through holes, such as 6, 8, or more through holes evenly spaced around the edges of the housing 802 or having another suitable arrangement. While through holes 812 illustrated in FIGS. 15B and 15C are oval in shape, in some examples, through holes 812 may have another suitable shape, such as circular, rectangular, hexagonal, etc. In some examples, the greatest cross-sectional dimension of each through hole 812 is less than or equal to 5 millimeters. In some examples, the greatest cross-sectional dimension of each through hole 812 is greater than 5 millimeters.

[0259] As previously mentioned, in one aspect, the through holes 812 are provided in housing 802 without separate (e.g., distinct from the enclosure 802a) anchor wings (e.g., 710a, 710b in FIGS. 12A-12E, or 770a-770d in FIGS. 14A-14E).

[0260] FIG. 15F is a diagram including a partial sectional view schematically representing the housing 802 of the IMD 800 securely engaging an anchoring tissue 790a (represented via section lines) with at least central segment 806c (of second face portion 806 of housing 802) engaging a surface portion 791 of anchoring tissue 790a. Fasteners F3, F5 (shown in dotted lines) (supported via through holes 812) engage portions 793a, 793b of the anchoring tissue 790a to pull (and maintain) at least the central segment 806c of second face portion 806 into engagement (e.g., contact) against the surface 791 of the anchoring tissue 790a. In some examples, this arrangement may comprise at least some of substantially the same features as the arrangement in FIGS. 14F, 14H regarding, at least, engagement of at least one protrusion (e.g., convexity 821c, 815c) and / or at least one recess (e.g., concavity 828a, 828b) of the central segment 806c corresponding to at least one protrusion (e.g., convexity 791b, 791c) and / or at least one recess (e.g., concavity 791c) of the surface portion 791 of anchoring tissue 790a.

[0261] In some examples, the arrangement shown in FIG. 15F may comprise a sectional view as taken along lines 15F—15F in FIG. 15G.

[0262] FIG. 15G also provides a schematic representation of engagement of second face portion 806 of housing 802 against anchoring tissue 790b. In some such examples, the arrangement shown in FIG. 15G may comprise a sectional view as taken along lines 15G—15G of previously described FIG. 15F such that the anchoring tissue 790b may generally correspond to anchoring tissue 790a in FIG. 15F, except seen from an orientation transverse to that shown in FIG. 15F.

[0263] As shown in FIG. 15G, in some examples housing 802 of IMD 800 securely engages anchoring tissue 790b (represented via section lines) with at least central segment 806c of second face portion 806 pressingly engaging a portion 797c of surface 797 of the anchoring tissue 790b with fasteners F3, F4 engaging portions 796a, 796b of the anchoring tissue 790b to pull (and maintain) at least the central segment 806c of second face portion 806 into engagement (e.g., contact) against the central portion 797c (e.g., a recess or concavity) of surface portion 797 of the anchoring tissue 790b. In some examples, the arrangement shown in FIG. 15G may 76 be implemented simultaneously with the arrangement shown in FIG. 15F via a single housing 802 of an IMD 800. It will be understood, however, that in some examples the arrangement in FIG. 15F may comprise an example implementation independent of the arrangement in FIG. 15G.

[0264] With further reference to FIG. 15G, among other aspects, in some examples, this arrangement may comprise at least some of substantially the same features as the arrangement in FIG. 14G regarding, at least, engagement of at least one protrusion (e.g., convexity 821c, 815c) and / or at least one recess (e.g., concavity 828a, 828b) of the central segment 806c corresponding to at least one protrusion (e.g., convexity 791a, 791b) and / or at least one recess (e.g., concavity 791c) of the surface portion 791 of anchoring tissue 790b.

[0265] Moreover, as further shown in FIG. 15G, in some examples the outer planar segments 806a, 806b of second face portion 806 may engage (e.g., press into, make contact with, etc.) one or more segments of the surface portion 797 of the anchoring tissue 790b with fasteners F3, F4 (supported via through holes 812) pulling and maintaining the planar segments 806a, 806b in secure engagement relative to the surface portion 797 (e.g., portions 797a, 797b) of the anchoring tissue 790b. As previously mentioned, the planar segments 806a, 806b may include additional topographic features (e.g., at least one convexity and / or at least one concavity), and / or may extend at angles different than shown in FIGS. 15A-15E, to enhance robust fixation of the housing 802 of IMD 800 relative to the anchoring tissue 790b.

[0266] Among other possible uses of an IMD 800 robustly secured relative to anchoring tissue 790b, the IMD 800 may comprise a stimulation lead connected to and extending from the housing 802 for applying electrical stimulation to a target tissue such as a nerve and / or muscle. In some examples, the anchoring tissue 790a 790b may comprise a mandible and the target tissue may comprise an upper airway patency-related nerve (or muscle), such as the hypoglossal nerve, and / or the anchoring tissue 790a, 790b may comprise other tissues (e.g., clavicle, SCM muscle, etc.) and the target tissue may comprise an infrahyoid muscle (IHM)-innervating nerve. Electrical stimulation of these target tissues may treat sleep disordered 77 breathing (SDB), such as obstructive sleep apnea. It will be further understood, as previously mentioned, that these same features may be employed to treat other conditions (e.g., urinary and / or fecal incontinence) in other regions (e.g., pelvic) of the body.

[0267] FIGS. 16A-16E are various views schematically representing an example IMD 830. In some examples, the IMD 830 comprises at least some of substantially the same features as, or an example implementation of at least some of the features of, the examples described in at least FIGS. 1A-11C and 23A-33.

[0268] FIG. 16A is a bottom view, FIG. 16B is a top view, FIG. 16C is a front view, FIG. 16D is a side view, and FIG. 16E is an isometric view of the IMD 830. The IMD 830 includes a housing 832, which may enclose a wireless receiver portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 832 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). In some examples, the wireless communication portion 303 comprises a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C).

[0269] The housing 832 includes a first face portion 834 (e.g., bottom face or first outer wall), a second face portion 836 (e.g., top face or second outer wall) opposite to the first face portion 834, end caps 837a and 837b coupled between the first face portion 834 and the second face portion 836, and sidewalls 838a and 838b coupled between the first face portion 834, the second face portion 836, and end caps 837a and 837b to form a lazy L-shaped enclosure. The first face portion 834 (e.g., first outer wall) includes a planar first segment 834a, a planar second segment 834b at an obtuse angle (e.g., pi tt) relative to the planar first segment 834a, and a curved (e.g., concave) third segment 834c extending between and connecting the planar first segment 834a and the planar second segment 834b. In some examples, the value of the obtuse angle may fall within a range of about 100 degrees to about 170 degrees. In some examples, the range may be about 120 degrees to about 150 degrees. In one aspect, the particular angle may correspond to a size, shape, and / or orientation of the anchoring tissue (e.g., muscle, bone, tendon, etc.) to which the housing 832 will be mounted in which the face portion 834 may partially enclose or partially wrap about the anchoring tissue such that segments 834a, 834c, and / or 834b of face portion 834 become secured (via fasteners supported by anchors 842a, 842b) into pressing engagement relative to the anchoring tissue.

[0270] The second face portion 836 (e.g., second outer wall) includes a planar first segment 836a, a planar second segment 836b at a reflex angle relative to the planar first segment 836a, and a curved (e.g., convex) third segment 836c extending between and connecting the planar first segment 836a and the planar second segment 836b. In some examples, the planar second segment 836b may include a window (e.g., 592 of FIG. 7C) through the housing 832. In some examples, the window may be formed of materials which facilitate wireless communication and / or other functions according to at least substantially the same features of the examples of at least FIG. 7C.

[0271] The first face portion 834 is coupled to (e.g., integral to, adhered to, welded to) the end caps 837a and 837b and the sidewalls 838a and 838b, which are coupled to (e.g., are integral to, adhered to, welded to) the second face portion 836 to form an enclosure having a length 850, a width 852 (FIG. 16B), and a maximum height 854 (FIG. 16D). In some examples, the length 850 is greater than the width 852, and the width 852 is greater than the maximum height 854. In some examples, the length 850 is at least 1.5 times, 2 times, 3 times, or 4 times the width 852. In some examples, the length 850 may be less than or equal to the width 852, and / or the width 852 may be less than or equal to the maximum height 854. In some examples, the length 850 may be less than or equal to 4 centimeters, the width 852 may be less than or equal to 2 centimeters, and the maximum height 854 may be less than or equal to 2 centimeters. As best illustrated in FIGS. 16B and 16E, the sidewalls 838a 79 and 838b include a first sidewall 838a and a second sidewall 838b opposite to the first sidewall 838a. The first sidewall 838a and the second sidewall 838b each extend between the end caps 837a and 837b. The first face portion 834 and the second face portion 836 each extend between and connect the first sidewall 838a, the second sidewall 838b, the first end cap 837a, and the second end cap 837b.

[0272] The housing 832 further includes suture anchors 842a and 842b protruding from the sidewalls 838a and 838b. The suture anchors 842a and 842b are for fixation of the housing 832 within a patient. A first suture anchor 842a protrudes from the sidewall 838a adjacent to the first segment 834a of the first face portion 834, and a second suture anchor 842a protrudes from the sidewall 838b adjacent to the first segment 834a of the first face portion 834 opposite to the first suture anchor. The suture anchors 842a include semicircular structures including circular through holes. In some examples, the suture anchors 842a may include another shaped structure (e.g., triangular, rectangular, trapezoidal, etc.) including a differently shaped through hole (e.g., oval, rectangular, triangular, hexagonal, etc.). A third suture anchor 842b protrudes from the sidewall 838a adjacent to the second segment 834b of the first face portion 834, and a fourth suture anchor 842b protrudes from the sidewall 838b adjacent to the second segment 834b of the first face portion 834 opposite to the third suture anchor. The suture anchors 842b include triangular structures including circular through holes. In some examples, the suture anchors 842b may include another shaped structure (e.g., semicircular, rectangular, trapezoidal, etc.) including a differently shaped through hole (e.g., oval, rectangular, triangular, hexagonal, etc.). While the housing 832 include four suture anchors 842a and 842b, in some examples, the housing 832 may include less than four suture anchors (e.g., 2) or more than four suture anchors (e.g., 6, 8, or more). In some examples, the greatest cross-sectional dimension of the through hole of each suture anchor 842a and / or 842b is less than or equal to 5 millimeters. In some examples, the greatest crosssectional dimension of the through hole of each suture anchor 842a and / or 842b is greater than 5 millimeters.

[0273] With further reference to at least FIG. 16D, it will be apparent that via the obtuse angle (pi tt) between the segments of 834b and 834a (of face portion 834), the suture anchors (842a and 842b) are oriented at the same angle relative to each other. This arrangement may facilitate leverage exerted via fasteners (e.g., sutures) extending through the anchor because such anchors may align the fasteners for direct penetration into anchoring tissue and / or align the fasteners for routing about a backside of an anchoring tissue before another end of suture arrives at one of other respective anchors.

[0274] In some examples, the housing 830 is configured for fixation to an anchoring tissue (e.g., with the first face portion 834 facing the anchoring tissue) for applying electrical stimulation via the IMD 830 to a hypoglossal nerve, an internal superior laryngeal nerve, an infrahyoid muscle (IHM)-innervating nerve, a phrenic nerve, and / or other nerves. The anchoring tissue may comprise a muscle such as (but not limited to) the mylohyoid, digastric, sternothyroid, sternohyoid, omohyoid, sternocleidomastoid (SCM) and / or other muscles. In some examples, the anchoring tissue may comprise non-nerve and / or non-muscle tissues such as bony structures, tendons, etc., which may include a mandible, hyoid bone, clavicle, thyroid cartilage, digastric tendon, etc.

[0275] FIGS. 17A-17E are various views schematically representing an example IMD 860. In some examples, the IMD 860 comprises at least some of substantially the same features as, or an example implementation of at least some of the features of, the examples described in at least FIGS. 1A-11C and 23A-33.

[0276] FIG. 17A is a lead end view, FIG. 17B is suture anchor end view, FIG. 17C is a side view, FIG. 17D is a first isometric view, and FIG. 17E is a second isometric view of the IMD 860. The IMD 860 includes a housing 862, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 20), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 860 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). In some examples, the wireless communication portion 303 may comprise a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C).

[0277] The housing 862 includes an outer wall 866 extending symmetrically along a major axis 867 (FIG. 17C) of the housing 862. A lead 863 is connected to a first end of the housing 862 through a connector 864. The housing 862 includes a suture anchor 872 arranged at a second end of the housing 862 opposite to the first end. As best illustrated in FIG. 17B, the suture anchor 872 may include a cross-shaped suture anchor including a plurality of struts 874a-874d (e.g., extensions, protrusions) coupled to an outer surface of the outer wall 866 for fixation of the housing 862 within a patient via at least one first suture. Each strut 874a-874d is at least partially spaced apart from and coupled to the outer wall 866. Each strut 874a-874d includes a first portion extending from the end of the outer wall 866 and a second portion joined to the second portions of the other respective struts 874a-874d. Thus, struts 874a and 874b form a first arch structure and struts 874c and 874d form a second arch structure perpendicular to and intersecting the first arch structure. In this way, the suture anchor 872 provides six paths under the suture anchor 872 (e.g., around strut 874a, around strut 874b, around strut 874c, around strut 874d, around the center of suture anchor 872 from between struts 874a and 874c to between struts 874d and 874b, or around the center of suture anchor 872 from between struts 874a and 874d to between struts 874c and 874b), such that a surgeon may select the best path (e.g., most aligned with tissue) for fixing the housing 862 within a patient. In some examples, the base of the first arch structure and the base of the second arch structure of the suture anchor 872 each have a width less than or equal to 5 millimeters. In some examples, the base of the first arch structure and the base of the second arch structure of the suture anchor 872 each have a width greater than 5 millimeters.

[0278] As best illustrated in FIGS. 17C-17E, the housing 862 also include a suture trench 870 extending around the outer surface of the outer wall 866 for fixation of the housing 862 within the patient via at least one second suture. The suture trench 870 may be arranged at the center of the housing 862 but also may be located at other portions of the exterior surface of the housing 862, in some examples. In some examples, the housing 862 may include further suture trenches (not shown) such as two or three suture trenches between the lead 863 end of the housing and the suture anchor 872 end of the housing.

[0279] As best illustrated in FIGS. 17C-17E, the suture trench 870 may include a semicircular channel, groove, or elongated recess or indentation extending into the surface of and extending axially around the outer wall 866. In some examples, the suture trench 870 may include a channel, groove, or elongated recess or indentation having another suitable shape, such as rectangular, triangular, trapezoidal, etc. A maximum depth of the suture trench 870 (e.g., at the center of the suture trench) may be within a range between 1 millimeter and 5 millimeters, and a width of the suture trench 870 may be within a range between 0.5 millimeters and 5 millimeters.

[0280] In some examples, the one or more suture trenches 870 also may comprise an orientation other than that shown in FIGS. 17A-17E, such as having an orientation parallel to a major axis of the housing 862 or a diagonal orientation like that shown in FIG. 13G, or other angled orientations. Any suture trench 870 with such alternate orientations may be the sole suture trench or may be in addition to the suture trench 870 shown in FIGS. 17C-17E which extends circumferentially about a periphery of the housing 862.

[0281] The outer wall 866 may have a maximum diameter 882 adjacent to each side of the suture trench 870 that gradually decreases towards both the suture anchor 872 end and the lead 863 end of the housing 862 to from an elliptical crosssectional shaped housing relative to axis 867. In some examples, the outer wall 866 may have a constant diameter to form a cylindrically shaped housing 862 (e.g., rectangular cross-sectional shaped housing relative to axis 867) or a variable diameter to form another cross-sectional shaped housing relative to axis 867, such 83 as triangular, bow tie, circular, hexagonal, etc. In some examples, the maximum diameter 882 of the housing 862 may be less than or equal to 2 centimeters, and a maximum length 880 of the housing 862 from the suture anchor 872 end to the lead 863 end may be less than or equal to 4 centimeters.

[0282] Among other aspects, a combination of the anchor 872 and the elongate arcuate shape of the housing 862 provides significant flexibility and maneuverability to position the housing 862 relative to a wide variety of potential anchoring tissues or combination of anchoring tissues. Moreover, among other features, the housing 862 omits anchor wing portions protruding outward from an outer wall of the housing 862, thereby providing a highly maneuverable profile amenable to easier access, delivery, and / or positioning within and among bodily tissues at which the housing 862 will be chronically implanted.

[0283] In some examples, the housing 862 is configured for fixation to a muscle, a tendon, or other soft tissue of a patient via the suture trench 870 and / or the suture anchor 872 with such anchoring tissues comprising at least some of substantially the same example anchoring tissues identified in association with at least FIGS. 16A-16E. Among other aspects, providing the suture anchor 872 at an end of the housing 862 may facilitate secure fixation of the housing 862 relative to anchoring tissues which are difficult to access if one were to attempt placing the full volume of the housing 862 directly against the anchoring tissue.

[0284] FIGS. 18A-18E are various views schematically representing an example IMD 900. In some examples, the IMD 900 comprises at least some of substantially the same features as, or an example implementation of at least some of the features of, the examples described in at least FIGS. 1A-110 and 23A-33.

[0285] FIG. 18A is a bottom view, FIG. 18B is a top view, FIG. 18C is a front view, FIG. 18D is a side view, and FIG. 18E is an isometric view of the IMD 900. The IMD 900 includes a housing 902, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-20 or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 902 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). In some examples, the wireless communication portion 303 may comprise a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C).

[0286] In some examples, the housing 902 includes a cuboid shaped (e.g., elongated cuboid, rectangular cuboid) first portion 904 having a length 920, a width 922 (FIG. 18C), and a height 924 (FIG. 18A), and the housing 902 includes a cuboid shaped second portion 906 having a length 926, a width 922, and a height 924 coupled to the first portion 904 and defining an end cap of the housing 902. The first portion 904 includes a first side face 904a, a second side face 904b, a third side face 904c, a fourth side face 904d, and an end face 904e. The first side face 904a is opposite to the second side face 904b, and the third side face 904c is opposite to the fourth side face 904d. The first side face 904a extends between and is perpendicular to the third side face 904c and the fourth side face 904d. The second side face 904b extends between and is perpendicular to the third side face 904c and the fourth side face 904d. The end face 904e extends between, is perpendicular to, and connects the first side face 904a, the second side face 904b, the third side face 904c, and the fourth side face 904d. The edges of each face 904a-904e where each face contacts another face 904a-904e may be rounded.

[0287] The second portion 906 includes a first side face 906a, a second side face 906b, a third side face 906c, a fourth side face 906d, and an end face 906e. The first side face 906a is opposite to the second side face 906b, and the third side face 906c is opposite to the fourth side face 906d. The first side face 906a extends between and is perpendicular to the third side face 906c and the fourth side face 906d. The second side face 906b extends between and is perpendicular to the third side face 906c and the fourth side face 906d. The end face 906e extends between, is perpendicular to, and connects the first side face 906a, the second side face 906b, 85 the third side face 906c, and the fourth side face 906d. The edges of each face 906a-906e where each face contacts another face 906a-906e may be rounded.

[0288] The first side face 904a of the first portion 904 is coupled to (e.g., integral to, adhered to, welded to) the first side face 906a of the second portion 906. The second side face 904b of the first portion 904 is coupled to (e.g., integral to, adhered to, welded to) the second side face 906b of the second portion 906. The third side face 904c of the first portion 904 is coupled to (e.g., integral to, adhered to, welded to) the third side face 906c of the second portion 906. The fourth side face 904d of the first portion 904 is coupled to (e.g., integral to, adhered to, welded to) the fourth side face 906d of the second portion 906. In some examples, the volume of the first portion 904 (e.g., length 920 times width 922 times height 924) is greater than the volume of the second portion 906 (e.g., length 926 times width 922 times height 924). In some examples, the volume of the first portion 904 may be less than or equal to the volume of the second portion 906. In some examples, the length 920 plus the length 926 is greater than the width 922, and the width 922 is greater than the height 924. In some examples, the length 920 plus the length 926 is at least 1.5 times, 2 times, 3 times, or 4 times the width 922. In some examples, the length 920 plus the length 926 may be less than or equal to the width 922, and / or the width 922 may be less than or equal to the height 924. In some examples, the length 920 plus the length 926 may provide an overall length of the housing 902 of less than or equal to 4 centimeters. In some examples, the width 922 of the housing 902 and / or the height 924 of the housing 902 may be less than or equal to 2 centimeters.

[0289] In some examples, the first portion 904 may include a metal (e.g., titanium, stainless steel, MP35N) and the second portion 906 may include a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., PEEK), or a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)). In these examples, a wireless communication element (e.g., 400 of FIG. 3A, 420 of FIG. 3B, 440 of FIG. 30) may be directly adjacent to (e.g., inside of) the second portion 906 of the housing 86 902 such that the thermoplastic polymer forming the second portion 906 may significantly enhance wireless power transfer and / or communication through a wall of the housing 902.

[0290] The housing also includes suture anchors 912a and 912b. A first suture anchor 912a is coupled to the first side face 906a of the second portion 906, and a second suture anchor 912a is coupled to the second face 906b of the second portion 906. Two cross-shaped suture anchors 912b are coupled to the end face 906e of the second portion 906. The suture anchors 912a and 912b are for fixation of the housing 902 to a muscle, a tendon, or other soft tissue of a patient. The suture anchors 912a each include a single arch structure under which at least one suture may pass through via a single path. The suture anchors 912b each include two arch structures perpendicular to each other and intersecting at the center of each arch structure, such that at least one suture may pass under the two arch structure via any one of six different paths. By including multiple paths under the suture anchors 912b, a surgeon may select the best path (e.g., most aligned with tissue) for fixing the housing 902 within a patient. In some examples, the suture anchors 912a may be replaced with the suture anchors 912b, or the suture anchors 912b may be replaced with the suture anchors 912a. In some examples, additional suture anchors 912a and / or 912b may be coupled to other faces of the second portion 906 and / or to one or more faces (e.g., 904a-904e) of the first portion 904. In some examples, the base of the arch structure(s) of each suture anchor 912a and / or 912b has a width less than or equal to 5 millimeters. In some examples, the base of the arch structure(s) of each suture anchor 912a and / or 912b has a width greater than 5 millimeters.

[0291] In some examples, the housing 902 is configured for fixation to a muscle, a tendon, or other soft tissue of a patient via the suture anchors 912a and / or 912b with such anchoring tissues comprising at least some of substantially the same example anchoring tissues identified in association with at least FIGS. 16A-16E.

[0292] FIGS. 19A-19E are various views schematically representing an example IMD 930. In some examples, the IMD 930 comprises at least some of substantially 87 the same features as, or an example implementation of at least some of the features of, the examples described in at least FIGS. 1A-11C and 23A-33.

[0293] FIG. 19A is a bottom view, FIG. 19B is a top view, FIG. 19C is a front view, FIG. 19D is a side view, and FIG. 19E is an isometric view of the IMD 930. The IMD 930 includes a housing 932, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 932 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). The wireless communication portion 303 may comprise a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C).

[0294] The housing 932 includes a first portion 934 and a second portion 936. The first portion 934 includes a first sidewall 934a (e.g., first side face), a second sidewall 934b (e.g., second side face), a third sidewall 934c (e.g., third side face), a fourth sidewall 934d (e.g., fourth side face), and a planar major face 934e (e.g., first major face or outer wall). The first sidewall 934a is opposite to the second sidewall 934b, and the third sidewall 934c is opposite to the fourth sidewall 934d. The first sidewall 934a extends between and is perpendicular to the third sidewall 934c and the fourth sidewall 934d. The second sidewall 934b extends between and is perpendicular to the third sidewall 934c and the fourth sidewall 934d. The planar major face 934e extends between, is perpendicular to, and connects the first sidewall 934a, the second sidewall 934b, the third sidewall 934c, and the fourth sidewall 934d. The edges of the sidewalls 934a-934d and / or the major face 934e may be rounded where they intersect.

[0295] The second portion 936 includes a major face (e.g., second major face or outer wall) opposite to the major face 934e including a first segment 936a (e.g., a planar or convex segment), a planar second segment 936b, and a third segment 936c (e.g., a planar or convex segment). The first segment 936a is opposite to the second segment 936b, and the third segment 936c extends between and connects the first segment 936a and the second segment 936b. The first segment 936a and the second segment 936b may each be at a reflex angle relative to the third segment 936c. The outer edges of each segment 936a-936c may be rounded where they contact sidewalls 934a-934d.

[0296] The first portion 934 of the housing 932 is coupled to (e.g., integral to, adhered to, welded to) the second portion 936 of the housing 932 to form a cuboid shaped enclosure have a length 950, a width 952 (FIG. 19A), and a height 954 (FIG. 19C). The first sidewall 934a is coupled to (e.g., integral to, adhered to, welded to) the first segment 936a, the second sidewall 934b is coupled to (e.g., integral to, adhered to, welded to) the second segment 936b, the third sidewall 934c is coupled to (e.g., integral to, adhered to, welded to) the third segment 936c, and the fourth sidewall 934d is coupled to (e.g., integral to, adhered to, welded to) the third segment 936c. In some examples, the length 950 is greater than the width 952, and the width 952 is greater than the height 954. In some examples, the length 950 is at least 1.5 times, 2 times, 3 times, or 4 times the width 952. In some examples, the length 950 may be less than or equal to the width 952, and / or the width 952 may be less than or equal to the height 954. In some examples, the length 950 may be less than or equal to 4 centimeters, and the width 952 and / or the height 954 may be less than or equal to 2 centimeters.

[0297] In some examples, the first portion 934 may include a metal (e.g., titanium, stainless steel, MP35N) and the second portion 936 may include a thermoplastic polymer (e.g., silicone, polysulfone, liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU)), a thermoset material (e.g., epoxy), a blend polymer material (e.g., PEEK), or a ceramic material (e.g., glass, aluminum oxide (AI2O3), zirconium oxide (ZO2)). In these examples, a wireless communication element (e.g., 400 of FIG. 3A, 420 of FIG. 3B, 440 of FIG. 30) may be adjacent to (e.g., directly adjacent to) the second portion 936 (e.g., third 89 segment 936c) of the housing 932 such that the thermoplastic polymer forming the second portion 936 may significantly enhance wireless power transfer and / or communication through a wall of the housing 932.

[0298] The housing 932 includes two suture anchors 942 coupled to the third sidewall 934c and two suture anchors 942 coupled to the fourth sidewall 934d. In some examples, the suture anchors 942 may also be coupled to the first sidewall 934a and / or the second sidewall 934b in addition to, or in place of, the suture anchors 942 coupled to the third sidewall 934c and the fourth sidewall 934d. In some examples, a single suture anchor 942 may be arranged on one or more of the sidewalls 934a-934d or more than two suture anchors 942 may be arranged on one or more of the sidewalls 934a-934d. In some examples as best illustrated in FIGS. 19D and 19E, each suture anchor 942 may be integral to (e.g., form a single unitary piece, be monolithic with) the second portion 936 (e.g., formed using the same injection molding process) via extensions 937 coupled between each suture anchor 942 and corresponding segments 936a, 936b, and / or 936c. Each suture anchor 942 may be proximate to the major face 934e of the first portion 934 (e.g., closer to the major face 934e than to the major face 936c and / or adjacent to the major face 934e).

[0299] Each suture anchor 942 includes a protruding structure including a through hole. In the example illustrated in FIGS. 19A-19E, each suture anchor 942 includes a generally triangular shaped structure with a rectangular shaped through hole extending through the structure. In some examples, each suture anchor 942 may include a structure having another shape, such as rectangular, trapezoidal, semicircular, etc. with a through hole having another shape, such as triangular, circular, oval, hexagonal, etc. extending through the structure. In some examples, the greatest cross-sectional dimension of the through hole of each suture anchor 942 is less than or equal to 5 millimeters. In some examples, the greatest cross-sectional dimension of the through hole of each suture anchor 942 is greater than 5 millimeters. Each suture anchor 942 may fix the housing 932 to tissue within a patient (e.g., with major face 934e facing the tissue). 90

[0300] In some examples, the housing 932 of IMD 930 is configured for fixation to an anchoring tissue (e.g., muscle, a tendon, or other soft tissue of a patient) via the suture anchor(s) 942 with such anchoring tissues comprising at least some of substantially the same example anchoring tissues identified in association with at least FIGS. 16A-16E.

[0301] FIGS. 20A-20F are various views schematically representing an example IMD 960a. In some examples, the IMD 960a comprises at least some of substantially the same features as, or an example implementation of at least some of the features of, the examples described in at least FIGS. 1A-11C and 23A-33.

[0302] FIG. 20A is a bottom view, FIG. 20B is a top view, FIG. 20C is a side view, FIG. 20D is a front view, and FIG. 20E is a back view, and FIG. 20F is an isometric view of the IMD 960a. The IMD 960a includes a housing 962, which may enclose a wireless communication portion (e.g., 303 of FIGS. 2A-2D), a stimulation element (e.g., 308 of FIG. 2A or 2C), a control portion (e.g., 310 of FIGS. 2B-2D), a power element (e.g., 312 of FIGS. 2B-2C or 600 of FIG. 9), a sensing element (e.g., 314 of FIG. 2D) such as a sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, etc.), electrical elements (e.g., 620 of FIG. 10), and / or other circuitry. The housing 962 may include a two-part housing (e.g., 502 of FIGS. 4A and 4B or 522 of FIGS. 5A and 5B) or an overmolded housing (e.g., 542 of FIG. 6A or 562 of FIG. 6B). In some examples, the wireless communication portion 303 comprises a wireless receiver (e.g., 304 of FIGS. 2A-2D) and / or a wireless communication element (e.g., 306 of FIGS. 2A-2D, 400 of FIG. 3A, 420 of FIG. 3B, or 440 of FIG. 3C).

[0303] In some examples, the housing 962 includes a convex first major face 964, a convex second major face 966, and sidewalls 968a-968d coupled between the first major face 964 and the second major 966 to form an enclosure 962a having a length 980, a width 982 (FIG. 20A), and a maximum height 984 (FIG. 20E). The sidewalls 968a-968d include a first sidewall 968a, a second sidewall 968b, a third sidewall 968c, and a fourth sidewall 968d. The first major face 964 is opposite to the second major face 966, the first sidewall 968a is opposite to the second sidewall 968b, and the third sidewall 968c is opposite to the to the fourth sidewall 968d. The first sidewall 968a extends between and is perpendicular to the third sidewall 968c and the fourth sidewall 968d. The second sidewall 968b extends between and is perpendicular to the third sidewall 968c and the fourth sidewall 968d. The first major face 964 extends between and connects the first sidewall 968a, the second sidewall 968b, the third sidewall 968c, and the fourth sidewall 968d. The second major face 966 extends between and connects the first sidewall 968a, the second sidewall 968b, the third sidewall 968c, and the fourth sidewall 968d. In some examples, the length 980 is greater than the width 982, and the width 982 is greater than the maximum height 984. In some examples, the length 980 is at least 1.5 times, 2 times, 3 times, or 4 times the width 982. In some examples, the length 980 may be less than or equal to the width 982, and / or the width 982 may be less than or equal to the height 984. In some examples, the length 980 may be less than or equal to 4 centimeters, and the width 982 and / or the height 984 may be less than or equal to 2 centimeters.

[0304] A plurality of electrodes 970 may be arranged on the surface of the second major face 966. While ten electrodes 970 are illustrated on the surface of the second major face 966 in FIGS. 20B and 20F, in some examples, the IMD 960a may include less than ten (e.g., 1, 2, 3, 4, 5, 6, 7, 8, or 9) or more than ten electrodes 970, and at least some of the electrodes may be arranged on one or more than one of the first major face 964, the second major face 966, and the sidewalls 968a-968d. At least some of the electrodes 970 may be used for sensing and / or at least some of the electrodes may be used for applying electrical stimulation. In some examples, some of the electrodes may be used for both sensing and stimulation, although not necessarily at the same time. In some examples, the electrodes 970 may have uniform spacing as shown in FIG. 20F, while in some examples, at least some of the electrodes 970 may be spaced non-uniformly relative to each other.

[0305] The IMD 960a further includes a suture anchor 972 coupled to the first sidewall 968a of the housing 962. The suture anchor 972 includes an arch 973 extending across, and spaced apart from, the first sidewall 968a from a portion directly adjacent to the third sidewall 968c to a portion directly adjacent to the fourth sidewall 968d. Sutures and / or other fastening elements may pass through a gap G formed by arch 973 to enable securing (e.g., fixating) the housing 962, via the anchor 972, relative to surrounding tissue. Moreover, in some examples, the arch 973 may serve as a handle on which a wire or suture may be fastened, wherein the wire or suture may act as a strap (as shown later in FIG. 22B) to retrieve the housing 962 if desirable to re-position the housing 962, such as during initial implantation of housing 962 of IMD 960a. In some such examples, arch 973 may be used for re-positioning in cooperation with a delivery tool, such as one example delivery tool 2010 as later described in association with at least FIG. 22A.

[0306] In some examples, the IMD 960a may further include a plurality of tines 974a (e.g., fingers, extensions) coupled to the housing 962. In the example illustrated in FIGS. 20A-20F, the IMD 960a includes a first tine 974a including a proximal end coupled to the third sidewall 968c and a second tine 974a including a proximal end coupled to the fourth sidewall 968d. In some examples, additional tines 974a may be coupled to the first major face 964 and the second major face 966 in addition to, or in place of, the tines 974a coupled to the third sidewall 968c and the fourth sidewall 968d. In this example, the tines 974a are spring tines, in which the distal end 975b is biased outward to be spaced apart from the sidewalls (e.g., 968c, 968d) and in which the distal end 975b of each tine 974a may be collapsed toward the housing 962 (e.g., toward the sidewalls 968c and 968d) during insertion of the IMD 960a into a patient using a tool as described below with reference to FIG. 22A. Once the IMD 960a is released from the tool, the distal end 975b of each spring tine 974a moves away from the housing 962 due to spring force to hold the IMD 960a in place within the patient by creating tension with the surrounding tissue. As illustrated in FIGS. 20A, 20B, and 20F, in some examples, the distal end 975b of each tine 974a may be bent or curved towards the housing 962.

[0307] FIG. 20G is a top view schematically representing an example IMD 960b. The IMD 960b is similar to the IMD 960a previously described and illustrated with reference to FIGS. 20A-20F, except that the IMD 960b includes tines 974b in place of tines 974a. In this example, the tines 974b are bimetallic tines. Each tine 974b includes two strips of different metals joined together. The two different metals have different coefficients of thermal expansion. At room temperature, the distal ends of the tines 974b may be retracted toward the housing 962 (e.g., toward the sidewalls 968c and 968d). Once the IMD 960b is implanted within a patient and reaches body temperature, however, one of the two metal strips expands more than the other one of the metal strips such that the distal ends of the bimetallic tines 974b move away from the housing 962 to hold the IMD 960b in place within the patient by creating tension with the surrounding tissue.

[0308] FIG. 20H is a top view schematically representing an example IMD 960c. The IMD 960c is similar to the IMD 960a previously described and illustrated with reference to FIGS. 20A-20F, except that the IMD 960c includes tines 974c in place of tines 974a. In this example, the tines 974c are electromechanical tines. Each tine 974c is constructed from shape memory alloys or muscle wires. Prior to implantation within a patient, the distal ends of the tines 974c may be retracted toward the housing 962 (e.g., toward the sidewalls 968c and 968d). Once the IMD 960c is implanted within a patient, an electric current is applied to the tines 974c to move the distal ends of the electromechanical tines 974c away from the housing 962 to hold the IMD 960c in place within the patient by creating tension with the surrounding tissue.

[0309] FIG. 21 is a top view schematically representing an example IMD 960d. The IMD 960d is similar to the IMD 960a previously described and illustrated with reference to FIGS. 20A-20F, except that the IMD 960d excludes the suture anchor 972 and the tines 974a. The housing 962 has a length 980 along a major axis of the housing and a width 982 along a minor axis of the housing. In some examples, the length 980 is greater than the width 982. For example, the length may be less than or equal to 4 centimeters, and the width may be less than or equal to 2 centimeters. In some examples, electrodes 970 may be arranged on the surface of housing 702 of FIGS. 12A-12E, housing 732 of FIGS. 13A-13E, housing 762 of FIGS. 14A-14E, housing 802 of FIGS. 15A-15E, housing 832 of FIGS. 16A-16E, housing 862 of FIGS. 17A-17E, housing 902 of FIGS. 18A-18E, or housing 932 of FIGS. 19A-19E.

[0310] While different suture anchor wings (e.g., 710a-710b of FIGS. 12A-12E, 770a-770d of FIGS. 14A-14E), suture anchors (e.g., 842a-842b of FIGS. 16A-16E, 872 of FIGS. 17A-17E, 912a-912b of FIGS. 18A-18E, 942 of FIGS. 19A-19E, or 972 of FIGS. 20A-20F), through holes (e.g., 812 of FIGS. 15A-15E), tines (e.g., 974a-974c of FIGS. 20A-20H), and suture trenches (e.g., 740a-740b of FIGS. 13A-13E or 870 of FIGS. 17A-17E) are described above for fixing different IMD housings within a patient as described above with reference to FIGS. 12A-20H, it is noted that the suture anchor wings, suture anchors, through holes, tines, and / or suture trenches may be combined with and / or replace the suture anchor wings, suture anchors, through holes, tines, and / or suture trenches of the other IMD housings described above with reference to FIGS. 12A-20H.

[0311] In some examples, the housing 962 of IMDs 960a-960d are configured for fixation to an anchoring tissue (e.g., muscle, a tendon, or other soft tissue of a patient) via the suture anchor 972 with such anchoring tissues comprising at least some of substantially the same example anchoring tissues identified in association with at least FIGS. 16A-16E.

[0312] FIG. 22A is a diagram schematically representing an example delivery tool 2010 for implanting an IMD in a patient. As shown in FIG. 22A, the delivery tool 2010 comprises a first portion 2020 and a second portion 2030 extending from the first portion 2020. The second portion 2030 may sometimes be referred to as an IMD-receiving portion or IMD-carrying portion. The second portion 2030 comprises a generally cylindrical sleeve or tube defined by a sidewall 2031 extending between a distal end 2032 and a proximal end 2034. The sidewall 2031 defines a lumen 2035 having a diameter (or greatest cross-sectional dimension), and a length, sized to slidably receive a housing of an IMD (e.g., 962 / 960a in FIGS. 20A-20F). In some examples, lumen 2035 defines a recessed pocket in which a housing (e.g., 962) of an IMD may be at least partially received or fully received, as shown in FIG. 22A.

[0313] In general terms, upon receivably mounting the housing 962 into the recessed pocket, the delivery tool 2010 may be maneuvered to orient the housing 95 962 toward and into an opening in a patient’s body for later deposit of the housing 962 of IMD within the patient’s body.

[0314] In some examples, the housing 962 may comprise at least one tine 974a (or 974b or 974c) on opposite sidewalls 968c, 968d as described above. Upon the housing 962 being slidably received within lumen / recessed pocket 2035, the sidewall 2031 of second portion 2030 of tool 2010 causes collapse of the tines 974a (represented by arrow C) of IMD 960a toward and against sidewall 968c, 968d of housing 962, which in turn temporarily prevents the tines 974a from engaging surrounding tissues while the tool 2010 is used to move the housing 962 of IMD 960a into a desired position close to a target implant location.

[0315] In some examples, the first portion 2020 of delivery tool 2010 extends proximally from the second portion 2030, and in some examples, the first portion 2020 includes a sidewall 2021 extending between a proximal end 2022 and a distal end 2024, with sidewall 2021 defining a lumen 2028. The distal end 2024 of first portion 2020 may be joined to the proximal end 2034 of second portion 2030 such that the lumen 2028 of first portion 2010 is in fluid communication with (e.g., open towards) the lumen 2035 of second portion 2030.

[0316] In some examples, the sidewall 2021 of first portion 2020 defines the lumen 2028 to have a diameter (or greatest cross-sectional dimension) smaller than the diameter (or greatest cross-sectional dimension) of the lumen 2035 of second portion 2030 such that the tool 2010 prevents unwanted migration of housing 962 from the lumen 2035 (in second portion 2030) into lumen 2028 (in first portion 2020).

[0317] In some examples, the example arrangement 2001 may comprise a pusher rod 2050 having a distal end 2052 and opposite proximal end 2054. The pusher rod 2050 may comprise a cross-sectional shape (e.g., circular, in some examples) compatible with a cross-sectional shape (e.g., circular, in some examples) of the lumen 2028 to permit slidable insertion, advancement, and withdrawal of the rod 2050 relative to lumen 2028. Among other functions, the rod 2050 may be slidably advanced within / through lumen 2028 (directional arrow PF) until distal end 2052 of rod 2050 protrudes from lumen 2028 into lumen 2035 (of second portion 2030) to 96 contact one end of housing 962. For instance, in the example shown, the distal end 2052 of rod 2050 may releasably contact the arch 973 of suture anchor 972, wherein further pushing of rod 2050 (per directional force arrow PF) toward and against housing 962, in turn, pushes the housing 962 out of lumen 2035 of second portion 2030 into a target location within the patient’s body.

[0318] Once a desired position of the housing 962 is established and secured in place via anchors 974a, the tool 2010 may be removed from the patient’s body. In some examples, sutures may be used in conjunction with anchor 972 and / or other fastening elements may be used to further secure the housing 962 in its established position relative to surrounding tissues.

[0319] As shown in FIG. 22B, in the event that it is desired to re-position the housing 962 / IMD 960a (e.g., during initial implantation), in some examples, the example arrangement 2060 may comprise a retrieval element 2062 (e.g., suture, string, strap, resilient rod, etc.). The retrieval element 2062 may be previously secured to arch 973 of anchor 972 or the retrieval element 2062 may be releasably secured (e.g., via a hook) to arch 973 at the time of retrieval. Upon pulling a proximal end 2063 of the retrieval element 2062, the housing 962 may be pulled back into the second portion 2030 of tool 2010 or pulled outwardly in the absence of tool 2010. Thereafter, further positioning attempts may be performed.

[0320] FIG. 23A is a diagram schematically representing an example stimulation portion 1370. In some examples, the stimulation portion 1370 may comprise at least some of substantially the same features and attributes as, and / or an example implementation of, the example leads and / or stimulation electrode arrangements described in association with at least FIGS. 1A-22B. In some examples, the stimulation portion 1370 may be used for both stimulation and sensing, while in some examples portion 1370 may comprise solely a sensing portion for sensing.

[0321] In some examples, the anchor structures, anchor portions, anchor elements, etc. described in association with at least FIGS. 23A-23C and 24A-24F may be implemented according to at least some of substantially the same features and attributes as anchor structures 6920, 6924, 6928 later described in association with 97 at least FIGS. 23D-23F and / or anchor structures 7000, 7100 later described in association with FIGS. 25A-25B.

[0322] As further shown in FIG. 23A, in some examples the stimulation portion 1370 comprises an anchor structure 1380 which extends along and around the entire or substantially the entire outer surface 1374 of the stimulation portion 1370 with at least some stimulation electrode arrangements 1376 interposed between segments of the anchor structure 1380 of anchor elements 1382. Each stimulation electrode arrangement 1376 may comprise one or more contact electrodes 1377 (i.e., stimulation electrodes). Among other aspects, the anchor structure 1380 stands in contrast to some leads which merely include a limited number of discrete anchor elements. Instead, the anchor structure 1380 provides a continuous or substantially continuous coverage of anchor elements on outer surface 1374 of the stimulation portion 1370. In some examples, the substantially continuous coverage may comprise covering at least about 50 percent of the total surface area of the outer surface 1374 of the stimulation portion 1370. In some examples, the substantially continuous coverage may comprise at least about 60 percent, at least about 65 percent, at least about 70 percent, at least about 75 percent, at least about 80 percent, at least about 85 percent, or at least about 90 percent.

[0323] In some examples, the continuous or substantially continuous coverage of outer surface 1374 with anchor elements 1382 may sometimes be referred to as a region of indefinite number of anchor elements 1382. In some such examples, the continuous or substantially continuous coverage of outer surface 1374 with anchor elements 1382 may sometimes be referred to as an anchor blanket, anchor layer, or anchor sheet.

[0324] Among other aspects, the anchor structure 1380 of stimulation portion 1370 may facilitate robust fixation of the lead segments 1372A, 1372B, 1372C, 1372D, etc. and / or stimulation electrode arrangements 1376 relative to surrounding tissues. At the same time, the relatively low profile of the anchor structure 1380 permits at least lateral advancement and maneuvering of the lead segments and / or the stimulation electrode arrangements of stimulation portion 1370 into target implant 98 positions (and orientations) as described in association with at least FIGS. 1A-1E, 11A-22B, and 28-31B.

[0325] FIG. 23B is a diagram 1390 including a sectional view schematically representing one example implementation of the stimulation portion 1370 of FIG. 23A. As shown in FIG. 23B, the example stimulation portion 1370 may comprise an example implementation of, and / or at least some of substantially the same features of the leads, stimulation portions, etc. as previously described in association with at least FIG. 1A-22B.

[0326] As further shown in FIG. 23B, the example stimulation portion 1370 comprises an anchor structure 1380, which includes a plurality of anchor elements 1382 which are formed on, or defined as part of, the outer surface 1374 of an outer wall 1319 of one of the lead segments (e.g., 1372A, 1372B, etc.), which define at least part of the stimulation portion 1370 (FIG. 23A). In some examples, the anchor structure 1380 defines a general pattern covering the entire or substantially the entire outer surface 1374 of the lead segment(s) (e.g., 1372A, 1372B, etc.) of the stimulation portion 1370. In some such examples, the anchor structure 1380 may comprise (or sometimes be referred to as) as anchor layer or anchor sheet.

[0327] FIG. 23C is a diagram 1392 including a sectional view schematically representing one example implementation of the stimulation portion 1370 of FIG. 23A (and sectional view of FIG. 23B), while including a contact electrode 1394 in electrical connection with one of the electrical conductors 1317 extending within an interior 1379 of one of the lead segments (e.g., 1372A, 1372B, etc.) of stimulation portion 1370. As shown in FIG. 23C, in some examples, the anchor elements 1382 may at least partially surround the contact electrode 1394.

[0328] FIG. 23D is a diagram 6900 including a side view schematically representing an example stimulation portion 6910. In some examples, the example stimulation element 6910 comprises at least some of substantially the same features and attributes as various stimulation portions, stimulation elements, etc. described in association with the figures of the present disclosure, while also comprising an anchor structure 6920 instead of another anchoring arrangement such as tines in FIG. 25C-25J or other types of anchor elements. In some examples, the stimulation portion 6910 may comprise a distal portion of a lead body which extends proximally from the proximal end 6718 of the stimulation portion 6910. It will be understood that anchor structure 6920 (e.g., plurality of anchor elements forming a matrix, pad, sheet, layer, etc.) may be substituted for the separate tines in the example arrangement of FIGS. 25C-25J and / or for other anchor structures in various examples throughout the present disclosure.

[0329] As shown in FIG. 23D, in some examples the anchor structure 6920 comprises a plurality of anchor elements 6924 which protrude from the sides 6711 of the body 6713 of the stimulation portion 6910. In some examples, the anchor elements 6924 may be grouped into different arrays 6922A, 6922B while in some examples, the anchor structure 6920 may comprise a single cluster of anchor elements 6924.

[0330] It will be understood that in some examples, the elements 6924 may extend about an entire periphery (e.g., circumference of body 6713).

[0331] As shown in FIG. 23D, the anchor structure 6920 is positioned distal to the electrode array 6714, being between the electrode array 6714 and the distal end 6719 of the body 6713 of the stimulation portion 6910. In this configuration, the position of the anchor structure 6920 on just one end (e.g., the distal end) of the electrode array 6714 may prevent or minimize “lead elongation”, i.e., elongation of the lead body 6713 which may potentially be caused by muscle movement when anchor elements (e.g., tines) are present on opposite ends of the electrode array 6714.

[0332] In some examples, the elements 6924 may comprise a filament (e.g., fine thread) which is flexible and resilient, and biased to extend outward from the side 6711 of body 6713. The filament may be formed of a polymer material, such as but not limited to, nylon, propylene, silk, polyester, trimethylene carbonate, and the like. In some examples, such filaments may be resorbable or may be non-resorbable.

[0333] In some examples, each element 6924 may comprise a diameter (or greatest cross-sectional dimension) of about 0.05 to about 0.60 millimeters. In some examples, each element 6924 may comprise a length of about 0.2 to about 2 millimeters. In some examples, each element 6924 may comprise a length about 0.5 percent to about 50 percent of a diameter of the lead body 6713 in the region of the electrode array 6714 and / or at distal end 6719. In some examples, at least some or all of the anchor elements 6924 may have generally the same shape, size, orientation, material, configuration, etc., such that the anchor elements 6924 may sometimes be referred to as being generally homogeneous anchor elements, i.e., being generally the same as each other.

[0334] However, in some examples, the anchor structure 6920 may be embodied as a matrix (e.g., grouped arrangement) of heterogeneous elements via filaments having pseudo-random sizes, shapes, orientations and / or positions exhibiting more variation than a plurality of identical or substantially similar discrete elements (e.g., 6927 in FIG. 23E), which may be visually recognizable. Meanwhile, in some examples, all of the various features of the matrix of heterogeneous elements may not be readily visually recognizable. Among other features, this heterogeneous matrix may enable fixation in both (e.g., opposite) orientations (along length of stimulation element / lead) and ease deliverability of the lead, lead portions. At least some example implementations of anchor structures 7000, 7100 comprising a matrix of heterogeneous elements are described later in association with at least FIGS. 25A-25B. In some examples, the heterogeneous elements may sometimes be referred to as heterogeneous fixation elements.

[0335] In some examples, the term matrix connotes a grouped arrangement of the fixation elements (e.g., anchor elements) in which the fixation elements are (structurally) independent from each other even though some of the fixation elements may at least partially contact each other in (at least) some instances. Stated differently, in some examples the grouped fixation elements do not interconnect with each other in a latticework or mesh format. In some examples, the fixation elements may be homogeneous relative to each other or in some examples, the fixation elements may be heterogeneous relative to each other. In some examples, the fixation elements may be oriented in near parallel planes, and in other examples, the 101 fixation elements could be in orientations with intersecting planes. In some examples, the relative orientation of the fixation elements can be random.

[0336] In some examples, the anchor structure 6920 may comprise a plurality of well-defined, discrete elements but with at least some of the discrete elements comprising a size, shape, orientation, and / or position different from a size, shape, orientation, and / or position of other respective discrete elements of the anchor structure 6920.

[0337] In some examples, the anchor structure 6920 may enhance some example methods of implantation of a stimulation device at least because the respective elements 6924 exhibit a low profile relative to an outer diameter of the body 6713 of the stimulation portion 6910 such that the stimulation portion 6910 (FIG. 23D-23F) can be delivered via a hollow insertion needle without a sleeve or similar elements (to temporarily collapse the elements 6924 during insertion) while the elements 6924 are still large enough to robustly secure the stimulation portion 6910 once free from the insertion needle.

[0338] As further shown in the greatly enlarged side view of just one element 6924 in FIG. 23E, in some examples, at least some (or all) of the elements 6924 may comprise protrusions 6927 on their surfaces, which in some examples may comprise barbs, hooks, or other sharp tipped structures. In some examples, the protrusions 6927 may be present on just a portion of the element 6924, such as but not limited to a distal portion 6929 of the element 6924. However, in some examples, the protrusions 6927 may be present on the entire or substantially entire surface of the element 6924. In yet other examples, groups of protrusions 6927 may be positioned in spaced apart clusters, which are spaced apart from each other along and around the surface of the element 6924.

[0339] It will be further understood that the protrusions 6927 are not strictly limited to structures having a sharp-tip or hook but may comprise structures comprising a rounded edge while including a sticky surface coating or formed as a non-sharp tipped member which can securely engage a surrounding non-nerve tissue in close proximity to a target stimulation site.

[0340] FIG. 23F is a diagram including a side view schematically representing an example protrusion 6928. In some examples, the protrusion 6928 may comprise at least some of substantially the same features and attributes as protrusion 6927 described in association with at least FIG. 23E and / or may comprise one example implementation of protrusion 6927. As shown in FIG. 23F, in some examples protrusion 6928 may comprise a main element 6923 for protruding outward (e.g., biased to extend outwardly at an angle) from an outer surface of a lead to function as part of an anchor structure, with protrusion 6928 including a first secondary element 6925A extending at an angle relative to the main element 6923. The combination of the first secondary element 6925A and the main element 6923 may sometimes be referred to as a barb at least to the extent that the respective main and secondary elements 6923, 6925A form a sharp point with the secondary element 6925A having an orientation which is at least partly opposite of the general orientation of the main element 6923. In some examples, the protrusion 6928 may further com prise additional secondary elements 6925B spaced apart from each other along a length of the main element 6923 and also extending outward at an angle relative to the main element 6923. In some examples, each secondary element 6925B also may comprise a barb, e.g., a further protrusion extending at an angle relative to the secondary element.

[0341] With regard to the example stimulation portion 6910 in FIGS. 23D-23F, it will be understood that in some examples the anchor structure 6920 may be located solely proximally of the electrode array 6714 such that no similar anchor structure 6920 is located distal to the electrode array 6714.

[0342] However, in some examples, a first anchor structure 6920 may be present distal to the electrode array 6714 as shown in FIG. 23D and a second anchor structure, similar to anchor structure 6920, may be present proximal to the electrode array 6714 so that at least some anchor structure or elements are present on opposite ends (e.g., sides when seen in the view of FIG. 23D) of the electrode array 6714. In some examples, elements 6924 of an anchor structure 6920 maybe located between adjacent electrodes 6716 of an array 6714 of electrodes.

[0343] Each of FIGS. 24A-24C is a diagram including a side view schematically representing an example stimulation portion (or portion of a stimulation lead body) including an anchor structure formed on, or defined at least partially by, an outer surface of the stimulation portion (or of the stimulation lead body). As previously noted elsewhere, in some examples the example stimulation portion may be used for stimulation and sensing while in some examples, the portion may be used solely for sensing. In some examples, each example anchor structure (1411 in FIG. 24A; 1421 in FIG. 24B; 1442 in FIG. 24C) may comprise at least some of substantially the same features and attributes of an anchor structure (and its associated stimulation portion or portion of a stimulation lead body) of the examples described in association with at least FIGS. 23A-23F or may comprise an example implementation of the anchor structure (and its associated stimulation portion or portions of a stimulation lead body) described in association with at least FIGS. 23A-23C. It will be further understood that such example anchor structures also may be incorporated into other example devices of the present disclosure, such as on an outer surface of at least a portion of a stimulation lead body, stimulation portion, other type of anchor element, etc.

[0344] As shown in the diagram 1400 of FIG. 24A, in some examples anchor structure 1411 may comprise a plurality of rows 1412 of anchor elements 1414 formed on (or defined as at least part of) an outer surface 1374 of a stimulation portion (or portion of a lead body) with spacing 1418 (e.g., absence of anchor elements 1414) interposed between adjacent rows 1412 of the anchor structure 1411. In this arrangement, the rows 1412 are circumferentially spaced apart. In one aspect, each row 1412 is aligned with (e.g., generally parallel to) a longitudinal axis (represented by line A) of the stimulation portion 1371 (or lead body). In some such examples, the size (e.g., width W11) of spacing 1418 and size (e.g., width W12) of the rows 1412 may be selected to implement a desired percentage of coverage of the surface area on the outer surface 1374 of the stimulation portion 1371. However, even with the spacing 1418, in some examples the anchor structure 1411 may sometimes be referred to as extending or covering the entire (or substantially the entire) length of the stimulation portion (or portion of lead body). It will be further understood that even with the inclusion of some minor interruptions (e.g., spaces) along a length of a row 1412 of the anchor structure 1411, the row 1412 (and anchor structure) may still be considered to extend the entire length (or substantially entire length) of the stimulation portion (or portion of stimulation lead body). For instance, one such non-limiting example of an interruption may comprise the presence of a stimulation electrode arrangement (e.g., array of stimulation electrodes) which is located along the length of the rows(s) 1412 of the anchor structure 1411.

[0345] With regard to the examples of at least FIGS. 24A-24D, in some examples a plurality of anchor elements (which may be organized into strips, pads, etc. in some examples) provide substantially continuous coverage (e.g., occupy a surface area) on an outer surface of at least one of a lead body, stimulation portion, or a stimulation element. In some such examples, the substantially continuous coverage comprises at least about 25 percent coverage, at least about 30 percent coverage, at least about 35 percent coverage, at least about 40 percent coverage, at least about 45 percent coverage, at least about 50 percent coverage, at least about 60 percent coverage, at least about 65 percent coverage, at least about 70 percent coverage, at least about 75 percent coverage, at least about 80 percent coverage, at least about 85 percent coverage, at least about 90 percent coverage, or at least about 95 percent coverage of the outer surface of at least one of a lead body, a stimulation portion (including distal lead segments and / or a stimulation element), or a stimulation element. It will be further understood that these examples of substantially continuous coverage may be applied to examples of the present disclosure regarding a plurality of anchor elements other than FIGS. 24A-24D.

[0346] With regard to the example of at least FIG. 24A in which rows 1412 extend longitudinally along the length of a lead body, a stimulation portion, and / or a stimulation element, the rows 1412 are spaced apart from each other circumferentially, wherein spacing between adjacent rows 1412 comprises an arc length of about 5 to about 10 degrees, of about 10 to about 20 degrees, of about 20 to about 30 degrees, of about 30 to about 40 degrees, of about 40 to 50 degrees, of 105 about 50 to about 60 degrees, of about 60 to 70 degrees, of about 70 to about 80 degrees, of about 80 to about 90 degrees, or of about 90 to about 120 degrees.

[0347] As shown in the diagram 1420 of FIG. 24B, example anchor structure 1421 may comprise at least some of substantially the same features and attributes of the anchor structure 1411 of FIG. 24A, except with the anchor elements 1414 arranged in a helical pattern of strips 1423A extending about the outer surface 1374 with spacing 1428 (e.g., absence of anchor elements 1414) interposed between adjacent strips 1423A. The dashed lines 1423B represent anchor strips on a backside of the stimulation portion not visible in the view of FIG. 24B, with strips 1423B being in general continuity with strips 1423A, in some examples. Among other aspects, the helically-patterned anchor structure 1421 may provide a desirable combination of sufficient anchorability in both the lateral and longitudinal orientations, while also permitting enough slidability in both the lateral and longitudinal orientations to facilitate implementing desired positioning of the stimulation elements of a stimulation portion at implant locations of target tissues. The helically-patterned anchor structure 1421 may sometimes be referred to as a spiral pattern. In some examples, spacing between adjacent turns about the outer surface 1374 may comprise at least some of substantially the same features regarding coverage and / or spacing as described in association with at least FIGS. 24A and 24C.

[0348] As shown in the diagram 1440 of FIG. 24C, example anchor structure 1442 may comprise at least some of substantially the same features and attributes of the anchor structure 1411 of FIG. 24A, except with the anchor elements 1414 on outer surface 1374 arranged in rows 1443 aligned perpendicular to the longitudinal axis (A) of the stimulation portion (or portion of lead body) with spacing 1448 (e.g., absence of anchor elements 1414) interposed between adjacent rows 1443 of anchor elements 1414. In some examples, the particular anchor structure may enhance longitudinal slidability while resisting lateral slidability, particularly after implantation.

[0349] In some such examples associated with FIG. 24C, the rows 1443 extend circumferentially with each row 1443 extending transverse to a longitudinal axis of a 106 lead (and / or stimulation element), at least in the region in which the rows 1443 are located, with the rows 1443 being spaced apart from each other longitudinally. In some such examples, the spacing (W14) between adjacent rows 1443 comprises at least one multiple, at least two multiples, or at least three multiples of a width (W13) of each row 1443.

[0350] FIG. 24D is a diagram 1450 including a sectional view schematically representing an example anchor structure 1452 for a stimulation electrode arrangement 1451. As shown in FIG. 24D, example anchor structure 1452 may comprise at least some of substantially the same features and attributes of (and / or an example implementation of) the anchor structures as described in association with at least FIGS. 23A-24C and 25A-25B, with anchor structure 1452 deployed on an outer surface 1454 of a housing of the stimulation electrode arrangement 1451 having at least one contact electrode 1458. As shown in FIG. 24D, in some examples the anchor structure 1452 comprises a plurality of anchor elements 1464 (like anchor elements 1414) extending over the surface area of the entire (or substantially the entire) outer surface 1454 of the stimulation electrode arrangement 1451, including lower and upper surfaces 1455A, 1455B, and side surfaces 1453A, 1453B, (and end surfaces not seen in the sectional view). As further seen in FIG. 24D, electrical conductors 1456 extend within and through the interior 1457 of the stimulation electrode arrangement 1451 with a respective one of the conductors 1456 being electrically connected (via link 1459) to the contact electrode 1458 on lower surface 1455A of the stimulation electrode arrangement 1451. Like the anchor structures present on lead segments (which extend between adjacent stimulation elements), the anchor structure 1452 on an outer surface 1454 of a stimulation element as in FIG. 24D may enhance securely fixing the stimulation electrode arrangement in a position of stimulating relation to target tissues in the manner of the examples of FIGS. 1A-22B.

[0351] In some examples, the anchor structures, anchor portions, anchor elements, etc. described in association with at least 23A-24F may be implemented according 107 to at least some of substantially the same features and attributes as anchor structures 7000, 7100 described in association with FIGS. 25A-25B.

[0352] FIG. 24E is a side plan view of a portion of an example stimulation lead including a stimulation portion 1340 comprising an anchor structure 1344 including anchor portions (e.g., 1345A, 1345B). In some examples, the stimulation portion 1340 may comprise at least some of substantially the same features and attributes as the stimulation portions described in associated with FIGS. 23A-24D.

[0353] As shown in FIG. 24E, the stimulation portion 1340 may comprise an array 1342 of spaced apart stimulation elements 1332L, 1332M, 1332N, 13320 within lead segment 1330I extending between elements 1332L and 1332M, lead segment 1330J extending between elements 1332M and 1332N, lead segment 1330K extending between elements 1332N and 13320, and so on. Lead segments 1330H and 1330L are present on opposite ends of the array.

[0354] In some examples, each stimulation element 1332L, 1332M, etc., and each lead segment 13301, 1330J, etc., may comprise a generally cylindrical shape. However, in some examples, each stimulation element 1332L, 1332M, etc. and / or each lead segment 1330I, 1330J, etc., may comprise a shape other than a generally cylindrical shape. Regardless of the particular shape, in some examples, the anchor elements 1347 may extend completely about a circumference of the respective lead segments (e.g., 13301, 1330J), or in some examples, may extend partially about a circumference of the respective lead segments (e.g., 13301, 1330J) per at least some of the example implementations described in association with at least FIGS. 23A-24D or described below in association with at least FIGS. 25A-27E.

[0355] As shown in FIG. 24E, in some examples the stimulation portion 1340 may comprise a first amount of spacing S1 between adjacent pairs of stimulation elements (e.g., 1332M, 1332N) which may be uniform in some examples. However, in some examples, as later shown in FIG. 24F, non-uniform spacing (e.g., S2, S1, and so on) may be implemented.

[0356] As further shown in FIG. 24E, each anchor portion 1345A, 1345B comprises an array of anchor elements 1347 arranged on a surface of a lead segment (e.g., 13301, 1330K) in a pattern, density, thickness, and / or orientation, such that anchor elements 1347 work individually and / or collectively to securely engage surrounding tissue to thereby secure at least a portion of the stimulation portion 1340 relative to the surrounding tissue. In addition to their collective arrangement, each anchor element 1347 may include barbs, protrusions, shapes, sizes, and / or orientations which enhance secure engagement of the surrounding tissue. In some examples, the anchor portions of FIGS. 24E-24F, such as, but not limited to, the anchor elements 1347 may comprise at least some of substantially the same features and attributes as, and / or an example implementation of, the anchor elements 6924 and related components as described in association with at least FIGS. 23D-23F.

[0357] In some examples, at least because such anchor portions 1345A, 1345B (FIGS. 24E-24F) are situated immediately adjacent to at least some stimulation elements (e.g., 1332L and 1332M or 1332N and 13320, respectively), the anchor portions may secure the stimulation elements to be maintained in a stable position in stimulating relation to nearby target tissues (e.g., target nerve portions, target muscle portions, and / or target neuromuscular junctions).

[0358] In some examples, the anchor structure 1344 may comprise a spacing S7 between the respective anchor elements 1347 which is substantially less than a spacing S1 between adjacent stimulation elements (e.g., 1332M, 1332N, etc.) on the stimulation portion 1340. In such some examples, the “substantially less” spacing may be implemented via the anchor structure 1344 comprising a spacing S7 between the respective anchor elements 1347 which is at least one order of magnitude less than a spacing S1 between adjacent stimulation elements (e.g., 1332M, 1332N, etc.) on the stimulation portion 1340. In some examples, the substantially less spacing may be implemented via the spacing S7 being at least two orders of magnitude less than the spacing S1 between adjacent stimulation elements (e.g., 1332M, 1332N, etc.). In some examples, the substantially less spacing may be implemented via the spacing S7 being 50 percent less than the spacing S1 between adjacent stimulation elements (e.g., 1332M, 1332N, etc.).

[0359] In some examples, these same relationships (of the spacing S7 between anchor elements 1347 being substantially less than the spacing S1) also apply to larger spacing(s) between adjacent stimulation elements, such as when there is a greater spacing between adjacent stimulation elements, such as spacing S2 in FIG. 24F between adjacent stimulation elements 1332R, 1332S which is greater than spacing S1 between adjacent stimulation elements 1332S and 1332T.

[0360] In some examples, such compressed spacing between adjacent anchor elements 1347 may be expressed as a density of the anchor elements 1347 in which the density may comprise a selected number of such anchor elements 1347 per area (e.g., square centimeters, square inches, and the like) of the stimulation portion 1340, such as on lead segments 1330I, 1330K, 1330Q, etc. In some such examples, the anchor elements 1347 may exhibit a density which is at least one order of magnitude greater than a density of the stimulation elements (e.g., 1332M, 1332N) among the lead segments, e.g., relative to the stimulation portion 1340 as a whole.

[0361] In some examples, the density may be expressed as a first ratio of a total number of anchor elements 1347 per total non-conductive surface area (e.g., surface area of the lead segments (e.g., 13301, 1330J) of the stimulation portion 1340 being substantially greater than a second ratio of a total number of stimulation elements (e.g., 1332L, 1332M, etc.) per total non-conductive surface area of the stimulation portion 1340. In some examples, the density may be expressed as a first ratio of a number of anchor elements 1347 per total non-conductive surface area (of the stimulation portion 1340) being substantially greater than a second ratio of a total number of stimulation elements (e.g., 1332L, 1332M, etc.) per total conductive surface area (e.g., a sum of the surface area of the exposed electrically conductive stimulation elements) of the stimulation portion 1340. In these examples, the term “substantially greater” may comprise at least one order of magnitude, at least two orders of magnitude, at least 200 percent greater, at least 100 percent greater, or at least 50 percent greater.

[0362] In some examples, as noted later in association with at least FIGS. 25A-25B (which may comprise features and attributes by which the anchor elements 1347 may be implemented), various anchor elements 1347 may extend from a support surface (e.g., lead segments 13301, 1330K, 1330Q, etc.) in different orientations (e.g., angular projection from the support surface) relative to each other and / or in different orientations relative to the stimulation elements 1332L, 1332M, etc. with such different orientations facilitating secure engagement of the collective group (or at least some of) the anchor elements 1347 relative to surrounding target tissue (e.g., non-nerve target tissue in some examples).

[0363] In some examples, the anchor elements 1347 may be arranged in patterns to facilitate securely engaging surrounding tissue and / or to facilitate maneuvering a stimulation portion (e.g., 1340) within and through surrounding tissue. In some such examples, one or more patterns may comprise at least some of substantially the same features and attributes as the patterns of anchor elements described in association with at least FIGS. 23A-24D and FIGS. 25A-27E and various examples throughout the present disclosure.

[0364] It will be understood that the stimulation portion 1340 represents an example segment of a stimulation portion which may comprise a greater or lesser number of stimulation elements (e.g., 1332L, 1332M, 1332N, 13320) than shown in FIG. 24E and that the anchor structure 1344 may comprise a greater number or lesser number of anchor portions 1345A, 1345B, etc. In some examples, as shown in FIG. 24E, anchor portions (e.g., 1345A, 1345B, etc.) are present between just some pairs of adjacent stimulation elements as shown in FIG. 24E, such that no anchor portions are present between some stimulation elements, such as stimulation elements 1332M and 1332N. Among other aspects, this arrangement may enhance a degree to which an implanted stimulation portion can flex in a manner complementary with flexion of the head-and-neck region.

[0365] However, in some examples, a respective one of the anchor portions 1345A, 1345B, etc. may be present between each and every pair of adjacent stimulation elements (e.g., between 1332L and 1332M, between 1332M and 1332N, between 1332N and 13320, and so on). Among other aspects, this arrangement may 111 increase a degree to which the stimulation portion 1340 (or certain portions thereof) is secured relative to non-target tissues and / or target tissues.

[0366] In some examples, the number and location (along the stimulation portion 1340) of anchor portions (e.g., 1345A, 1345B) may be based on the number and location of stimulation elements 1332L, 1332M, 1332N, 1332L, 13320, etc. and the relative spacing between such stimulation elements. Moreover, in some examples, the stimulation portion 1340 may comprise the same amount of uniform spacing (S1) between adjacent stimulation elements.

[0367] However, in some examples such as the example stimulation portion 1350 in FIG. 24F, a first amount of spacing S1 between one adjacent pair of stimulation elements (e.g., 1332S, 1332T) may be different from a second amount of spacing (S2) between another adjacent pair of stimulation elements (e.g., 1332R, 1332S). This different amount of spacing may be used to cause a stimulation element (e.g., 1332R) to likely become positioned at a particular anatomical location (e.g., second nerve portion, second muscle portion) in view of another stimulation element (e.g., 1332S or 1332T) likely becoming positionable at another particular anatomical location (e.g., first nerve portion, first muscle portion, etc.). In some examples, having different amounts of spacing between at least some of the stimulation elements may enhance the adaptability of the stimulation portion 1350 to accommodate anatomical variations among different patients in whom the stimulation portion 1350 may be implanted.

[0368] Moreover, in some examples, at least because of the size (e.g., length, diameter, etc.), shape, flexibility, etc. of the lead segments (e.g., 13301-1330L in FIG. 24E) extending between the adjacent stimulation elements (e.g., 1332L and 1332M, 1332M and 1332N, 1332N and 13320 in FIG. 24E), these interposed lead segments (e.g., 13301-1330L in FIG. 24E) may be positioned in desired curved shapes, angles, planes, orientations, etc. to enable placing the respective stimulation elements (e.g., 1332L-1332O) at target stimulation locations of target nerve portions, target muscle portions, neuromuscular junctions, and / or combinations thereof. In some such examples, at least an outer jacket of the flexible lead segments may comprise a 112 resilient material such that the lead segments may be flexibly curved, bent, etc. into their desired shape, but will return to an original shape in the absence of some force or restraint holding the flexible lead segment into the shape, configuration, etc. into which it was manipulated.

[0369] In some examples, at least some of the respective lead segments 1330H-1330L and / or at least some of the stimulation elements 1332L-1332O may be positionable adjacent significant non-nerve tissues at which anchoring may be beneficial. For instance, some example non-nerve tissues may comprise tendons of external lingual muscles (or muscles ofairway patency), more specifically, tendons of the geniohyoid and hyoglossus muscles.

[0370] As shown in FIG. 24E, in some examples the stimulation elements (e.g., 1332L) may comprise a height (H1) (e.g., thickness) relative to a surface of the lead segments (e.g., 1330H, 13301) and the anchor portion 1345A may comprise a height (H2) (e.g., thickness).

[0371] In some examples, the height H2 of the anchor portions 1345A, 1345B may comprise a height equal to or less than the height H1 of the stimulation element(s) (e.g., 1332L). In one aspect, this arrangement may facilitate engagement of the stimulation elements (e.g., 1332L) with the target tissues to which the stimulation elements (e.g., 1332L) are to be placed into stimulation relation. Moreover, a relatively low height H2 of the anchor portions 1345A, 1345B may enhance maneuvering of the respective lead segments (e.g., 13301, 1330J, etc.) and / or stimulation elements (e.g., 1332L, 1332M) for implantation relative to target tissues. Nevertheless, despite their limited height H2, an orientation, shape, diameter, position, spacing, density, etc. of the anchor elements 1347 (in combination with their height) provides for sufficiently robust engagement and fixation relation to the surrounding tissues once a final implant location has been established.

[0372] On the other hand, in some examples, the height H2 of anchor portions 1345A, 1345B may comprise a height greater than the height H1 of the stimulation element(s) (e.g., 1332L) as shown in FIG. 24E, which may provide for more aggressive engagement of surrounding tissues. However, in some examples, even if the anchor portions 1345A, 1345B have a height H2 greater than the height H1 of the stimulation elements (e.g., 1332L), the height H2 still may be generally less than a height of conventional tines, etc. which typically have a height significantly exceeding the height H1 of the stimulation elements (e.g., 1332L). Accordingly, the relatively low height H2 of the anchor portions 1345A, 1345B may permit sufficient maneuvering of the stimulation portion for implantation while the height H2, in concert with the orientation, shape, diameter, position, spacing, density, etc. of the anchor elements 1347, provides for sufficiently robust engagement and fixation relation to the surrounding tissues once a final implant location has been established.

[0373] In some examples, the anchor portions of FIGS. 24E-24F may be implemented via at least some of the features and attributes of the example anchor structures described in association with at least FIGS. 25A and / or 25B. In one aspect, additional aspects regarding a height (e.g., H2 in FIG. 24E) of an anchor portion (e.g., 1345A, 1345B) are described in association with at least FIGS. 25A-25B.

[0374] FIG. 24F is a side plan view of a portion of an example stimulation portion 1350 comprising an anchor structure 1354. In some examples, the stimulation portion 1350 may comprise at least some of substantially the same features and attributes as the stimulation portions of FIGS. 23A-24E, and the stimulation portion 1350 of FIG. 24F may comprise one example implementation of the stimulation portions of at least FIGS. 25A-25B.

[0375] As shown in FIG. 24F, the stimulation portion 1350 may comprise an array of spaced apart stimulation elements 1332R, 1332S, 1332T within lead segments 1330Q, 1330R interposed therebetween and lead segments 1330P, 1330S on opposite ends of the array of stimulation elements 1332R, 1332S, 1332T. It will be understood that the stimulation portion 1350 represents an example segment of a stimulation portion which may comprise a greater or lesser number of stimulation elements (e.g., 1332R, 1332S, 1332T) than shown in FIG. 24F and may comprise a greater or lesser number of anchor portions 1353A, 1353B, 1355A, 1355B, 1357A, 1357B. In some examples, the anchor portions (e.g., 1353A, 1353B; 1355A, 1355B; 114 etc.) may be present for each stimulation element (e.g., 1332R; 1332S; etc.) or for just some stimulation elements, in some examples.

[0376] In some examples, the anchor portions 1353A, 1353B, etc. comprise at least some of substantially the same features and attributes as the anchor portions 1345A, 1345B in FIG. 24E, except not entirely filling the space along a lead segment (e.g., 1330Q) between adjacent stimulation elements (e.g., 1332R, 1332S), a lead segment (e.g., 1330R) between adjacent stimulation elements (e.g., 1332S, 1332T), and so on.

[0377] In some examples, such as shown in FIG. 24F, the anchor portions (e.g., 1353A, 1353B) are provided in pairs such that at least some (or all) of the stimulation elements (e.g., 1332R) are sandwiched between the respective pair of anchor portions 1353A, 1353B while still leaving a significant proportion of an adjacent lead segment 1330Q to be free of anchor portions (or at least having significantly fewer anchor elements 1347). In one aspect, this arrangement of omitting anchor elements (e.g., 1347) along portions of the lead segments (e.g., 1330Q) may enhance advancement and maneuverability of the lead segments (e.g., 1330Q, 1330R) while the anchor portions 1353A, 1353B sandwiching the stimulation elements (e.g., 1332R) provides for robust fixation of the stimulation elements (e.g., 1332R) at a desired implant location. In some such examples, the anchor portions 1353A, 1353B may sometimes be referred to be at a respective stimulation element and not along a lead segment extending from the respective stimulation element.

[0378] In some examples, just one portion (e.g., 1353A or 1353B) of a pair of anchor portions (e.g., 1353A, 1353B) may be present at some of the stimulation elements. This arrangement may enhance positioning of at least some of the stimulation elements relative to certain types of anatomical variations of patient anatomy. In some such examples, just anchor portions 1353A, 1355A, 1357A (and so on) may be present or just anchor portions 1353B, 1355B, 1357B (and so on) may be present. In one aspect, such example arrangement may provide an anchor portion (e.g., 1353A, 1355A) for each stimulation element, yet may enhance 115 slidability of advancing and positioning the various stimulation elements relative to various anatomical structures.

[0379] Moreover, depending on the direction and / or orientation of positioning the various stimulation elements and anchor portions within the patient, starting from a midline implant-access incision (in some examples), it may be desirable to include solely or mostly anchor portions which trail a direction or orientation of advancement of the stimulation portion within the patient anatomy.

[0380] Accordingly, in some examples, one may assume that strictly for example purposes, the anchor portions 1353B, 1355B, 1357B may be on the trailing end of an advancement direction of the stimulation portion 1350, which may enhance slidability for initial positioning but still provide sufficient anchoring traction once the initial positioning is complete. In some such examples, only anchor portions 1353B, 1355B, 1357B are included (with anchor portions 1353A, 1355A, 1357A being omitted).

[0381] Conversely, in some examples, one may assume that strictly for example purposes, the anchor portions 1353A, 1355A, 1357A may be on the leading end of an advancement direction of the stimulation portion, which may enhance anchoring traction as the initial positioning is being implemented. In some such examples, only anchor portions 1353A, 1355A, 1357A are included (with anchor portions 1353B, 1355B, 1357B being omitted).

[0382] However, in some examples, advancement of the stimulation elements (e.g., 1332R, 1332S, etc.) and / or the lead segments (e.g., 1330Q, 1330R, etc.) may occur laterally such that the respective anchor portions 1353A, 1353B may neither enhance nor hinder advancement and positioning of the stimulation elements (e.g., 1332R, 1332S) during movement of the stimulation portion.

[0383] Among other aspects, the low profile (e.g., relatively low height) of the example anchor portions (e.g., FIGS. 24E-24F) may enhance maneuverability of a stimulation portion among and within target tissues while still maintaining a desirable level of secure fixation. In one aspect, such low profile arrangements stand in 116 contrast to more conventional high profile anchor(s) which may extend outwardly far beyond a surface of a lead or an outer surface of a stimulation element.

[0384] FIG. 25A is a diagram including an enlarged top view schematically representing an example anchor structure 7000 formed on, and including as part of the anchor structure, a base 7002. In some examples, the anchor structure 7000 may comprise an analogous example implementation of the anchor structure 6920 in FIGS. 23A-23F and may comprise at least some of substantially the same features and attributes as the anchor structure 6920, particularly with respect to providing a matrix of heterogeneous elements. However, in some examples, the anchor structure 7000 of FIG. 25A may have wide applicability to act as an anchor or position-influencing element. In some examples, the anchor structure 7000 in FIG. 25A may comprise one example implementation of at least some of the features of the anchor structures, anchor portions, anchor elements in the examples in association with at least FIGS. 23A-24D and may comprise at least some of substantially the same features and attributes as the anchor structures, anchor portions, anchor elements, etc. in the examples in association with at least FIGS. 23A-24D.

[0385] As shown in FIG. 25A, the anchor structure 7000 may comprise an array 7010 of example heterogeneous elements 7012, 7013, 7016 formed on (and / or extending upward from) a surface 7005 of base 7002. In some examples, the surface 7005 may comprise a planar surface and in some examples, the surface 7005 may comprise a non-planar surface. Together, the heterogeneous elements 7012, 7013, 7016 may form a matrix, network, or the like which may overlap or otherwise be juxtaposed relative to each other to create a generally traction-favoring surface profile. It will be understood that in some examples, the various heterogeneous elements of array 7010 may be positioned much closer to each other than shown in FIG. 25A in order to touch, overlap, partially interlock or interfere with each other, etc. so as to increase the frictional properties (e.g., slide-resistance) of the anchor structure or to reduce the frictional properties (e.g., slidability) of the 117 anchor structure, depending on the type, size, orientation, coating, etc. of the particular arrangement of elements of the array 7010.

[0386] In general terms, the various elements of the array 7010 may comprise a flexible, resilient material. However, depending on the goals regarding slidability or slide-resistance, some elements may be firmer or softer.

[0387] In some examples, the particular types, spacing between, orientation, position, relative flexibility, etc. of the heterogeneous elements of the array 7010 may be selected and formed to correspond to a selectable coefficient of kinetic friction to enable a desired bias for controlled slidable movement relative to tissues within a patient’s body and / or relative to lumen within a patient’s body and / or to correspond to a selectable coefficient of static friction to enable a desired bias to remain statically positioned at a chose location relative to tissues or within a lumen.

[0388] In some examples, whether or not expressed formally as a coefficient of kinetic or static friction, the various heterogeneous elements of the array 7010 are selected and formed according to their height, size, shape, position, spacing, orientation relative to each other, relative flexibility, etc. to create a desired anchoring effect while still permitting some degree of slidable advancement.

[0389] As shown in FIG. 25A, at least some example shapes (as seen in crosssection from a top view) may comprise elements with shapes which are triangular 7012, circular 7013, rectangular 7016, and the like. The elements also may have different sizes (e.g., diameter, greatest cross-sectional dimension, width, and the like such as represented by S4), and spacing (e.g., S3) between each other or relative to an edge 7031 (e.g., S8) of the base 7002. In some examples, at least some of the elements of array 7010 may comprise hook-shapes, J-shapes, U-shapes, etc. In some examples, at least some of the elements, or the juxtaposed pattern of such elements, may promote tissue in-growth and long term fixation, such as but not limited to, apertures formed in such elements or by the juxtaposition of some of the respective elements.

[0390] The various elements also may be organized in directional patterns, such as being in rows aligned in a first orientation (R1) or second orientation (R2) which 118 are orthogonal to each other, or in other non-orthogonal orientations. Such orientations may be used to effect selectable bias to permit or prevent slidable movement in various directions, which may enhance positioning and / or anchoring of the medical element on which the anchor structure 7000 is located.

[0391] In some examples, at least some elements of the array 7010 may be arranged along a periphery 7030 of the base 7002 in a row or other organizational pattern. The elements 7034 in one example row 7032 may have the same height, size, shape, positions, etc. or may have heights, sizes, shapes, positions different from each other. By providing this configuration along one or more edges 7031 of the base 7002, the anchor structure 7000 may influence slidability or slide-resistance in particular directions. In a related aspect, the presence or absence of elements of array 7010 in an interior portion 7040 also may provide analogous influences, with or without the edge-type rows, etc. of such elements.

[0392] In some examples, the interior portion 7040 of the base 7002 and / or the elements of array 7010 also may comprise a coating with desired lubricous and / or frictional qualities, which may be selected to work synergistically with the various shapes, sizes, positions, spacing, orientation, etc. of the elements of array 7010.

[0393] FIG. 25B is a diagram including an enlarged side view schematically representing an example anchor structure 7100 formed on, and including as part of the anchor structure, a base 7002. In some examples, the anchor structure 7100 may comprise an analogous example implementation of the anchor structure 6920 in association with at least FIGS. 23A-23F and may comprise at least substantially the same features and attributes as the anchor structure 6920, particularly with respect to providing a matrix or network of heterogeneous elements. However, in some examples, the anchor structure 7100 may have wide applicability to act as an anchor or position-influencing element.

[0394] In some examples, the anchor structure 7100 in FIG. 25B may comprise at least some of substantially the same features and attributes as anchor structure 7000 in FIG. 25A.

[0395] As shown in FIG. 25B, the anchor structure 7100 comprises an array 7110 of elements comprising different shapes, sizes (e.g., heights, diameters, etc.), positions, spacing, orientations, etc. For example, rectangular elements 7130A, 7130B, 7130C, 7130D exhibit differing angular orientations (e.g., relative to a horizontal plane through which base 7002 extends), which may sometimes be referred to as being bi-directional or multi-directional. Other elements may comprise spherical shaped elements 7120A, 7120B, pyramid-shaped elements 7122, etc. The respective elements of array 7110 may be formed according to a selectable height (per height arrow H3), which may vary from each other as part of a desired effect to promote slidability or slide-resistance, depending on the intended use of the anchor structure and medical element to which is formed / attached.

[0396] It will be further understood that some shapes, such as the spherical elements 7120A, 7120B may be more likely to enhance slidability because of their smooth convex surface while some shapes, such as the pyramid element 7122 or rectangular elements (7130A-7130D), may enhance slide-resistance, depending on their orientation. In some examples, directional arrow S10 may represent relative horizontal spacing between elements of array 7110.

[0397] In some examples, the base 7002 may be formed in a two-dimensional plate shape, such that the anchor structure 7000 (FIG. 25A) or 7100 (FIG. 25B) may be readily formed or attached to a back side of a carrier opposite to an electrode side of a stimulation portion, such as a paddle-shaped carrier which carries contact electrodes. However, in some examples, the base may comprise a cylindrical shape such that the elements of array 7010 (FIG. 25A) and / or array 7110 (FIG. 25B) may extend circumferentially outward from a cylindrically shaped lead on which the array 7010 (FIG. 25A) or 7110 (FIG. 25B) is formed or attached. Examples are not so limited, and the base may comprise other shapes as well.

[0398] In some examples, and with general reference to anchoring examples in association with at least FIGS. 23A-24D and 25A-25B, an anchor structure comprising a plurality of anchor elements may comprise homogeneous elements and / or heterogeneous elements. In some such examples, at least a majority of the homogeneous anchor elements may comprise substantially the same size, shape, position, and / or orientation relative to each other. In some examples, the percentage of anchor elements which are homogeneous relative to each other may comprise at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95%.

[0399] In some such examples, at least a majority of the heterogeneous anchor elements (e.g., FIGS. 25A-25B) may comprise a different size, different shape, different position, and / or different orientation relative to each other. In some examples, the percentage of anchor elements which are heterogeneous relative to each other may comprise at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95%.

[0400] With regard to at least some of the example homogeneous anchor elements and / or example heterogeneous anchor elements of the present disclosure, each respective anchor element is separate from other respective anchor elements, and a quantity of the plurality of anchor elements is substantially different from, being greater than, at least one of: (A) a quantity of electrodes on at least one of: (1) a single stimulation portion of multiple stimulation portions; and (2) all of the stimulation portions for a lead; and (B) a quantity of all the stimulation portions.

[0401] With regard to at least some of the example homogeneous anchor elements and / or example heterogeneous anchor elements of the present disclosure, at least some of the respective anchor elements extend outwardly from an external surface of a lead segment (or lead body) by a first distance which is substantially different from, being less than, at least one of a diameter of, a greatest cross-sectional dimension of, or a thickness of the lead segment (or lead body).

[0402] With regard to at least some of the example homogeneous anchor elements and / or example heterogeneous anchor elements of the present disclosure, at least some of the respective anchor elements extend outwardly from an external surface of a carrier body of a stimulation portion (e.g., a carrier body supporting contact 121 electrodes) by a first distance which is substantially different from, being less than, at least one of a diameter of, a greatest cross-sectional dimension of, or a thickness of the stimulation element (e.g., the carrier body of the stimulation portion).

[0403] With regard to at least some of the example homogeneous anchor elements and / or example heterogeneous anchor elements of the present disclosure, at least some of the respective anchor elements comprise a diameter or a greatest crosssectional dimension which is substantially different from, being less than, a surface area of a respective one of the electrodes of the stimulation portion. In some such examples, in this context the diameter (or greatest cross-sectional dimension) of the anchor elements is substantially less than a total surface area of all electrodes of a respective one of the first and second stimulation portion.

[0404] FIG. 25C is a diagram 1470 including a sectional view schematically representing an example stimulation portion 1471 (or portion of a stimulation lead body) of an example device and / or example method comprising at least some of substantially the same features and attributes as (but not limited to) the examples described in association with at least FIGS. 1A-22B, except comprising a fixation structure 1474 comprising a plurality of tines 1475 extending about the outer surface 1472 of the stimulation portion 1471. As shown in FIGS. 25C-25D, the tines 1475 extend generally perpendicular to a longitudinal axis (reference line A) of the stimulation portion 1471 (or portion of stimulation lead body) and parallel to a minor axis (reference line B) of the stimulation portion 1471.

[0405] Moreover, as further shown in FIGS. 25C-25D, in some examples, the stimulation portion (or portion of stimulation lead body) 1471 may be advanced within the patient’s body in an orientation (represented by directional arrow LT) which is lateral (e.g., transverse) to a longitudinal axis (line A) of the stimulation portion 1471, which stands in contrast to the typical advancement of a stimulation lead portion in alignment with a longitudinal axis (A) of the stimulation portion 1471. Accordingly, the tines 1475 are aligned to enhance lateral stability of the stimulation portion 1471 more substantially than longitudinal stability of the stimulation portion 1471 while also making the stimulation portion 1471 more maneuverable in a lateral orientation (as represented by directional arrow LT) in order to advance and place the stimulation lead portion(s) in the arrangement in the example methods in which the stimulation portions (e.g., stimulation electrode arrangement) and / or lead segments are implanted with minor tunneling or no tunneling, such as (but not limited to) via a direct visualization of the target tissues at which the stimulation portions (and / or supporting lead segments) may be maneuvered more directly to their implant locations at which stimulating relation (relative to target tissue) is established.

[0406] As in other examples, electrical conductors 1456 may extend through and within an interior of the stimulation portion (or portion of stimulation lead body) 1471.

[0407] In some examples, the anchor structure may sometimes be referred to as generally providing sideways tines (e.g., being oriented laterally) in at least some lead segments of a stimulation portion versus longitudinal-oriented tines.

[0408] FIG. 25D is a diagram 1480 including a top plan view schematically representing the stimulation portion 1471 of FIG. 25C. As shown in FIG. 25D, tines 1475 are spaced apart from each other along a length (e.g., longitudinal axis A) of the stimulation portion 1471 with a longitudinal axis of tines 1475 aligned with an expected generally lateral orientation (LT) (versus a more traditional longitudinal orientation) of advancement of the stimulation portion 1471 within the patient’s body during at least some of the implantation of the stimulation portion 1471 in some examples. FIG. 25D also further illustrates the stimulation portion 1471 having opposite ends 1481 A, 1481B and opposite sides 1473A, 1473B.

[0409] FIG. 25E is a diagram 1483 including a top plan view like that of FIG. 25D schematically representing an example stimulation portion 1482 comprising at least some of substantially the same features and attributes as the stimulation portion 1471 of FIG. 25C-25D, except with tines 1485 (like tines 1475) arranged at a slant (e.g., an angle lambda A) such that a length (e.g., longitudinal axis LA) of the tines 1485 are not perpendicular to the longitudinal axis (line A) of the stimulation portion 1482 or not parallel to the minor axis B of the stimulation portion 1482. The angle A is selected such that the tines 1485 help to resist “backing out” of the stimulation portion 1482 from an implanted location along the lateral orientation LT (along or 123 parallel to line B) while simultaneously preventing any significant shifting of the stimulation portion 1482 in the longitudinal orientation (along line A).

[0410] Via this arrangement, the angled tines 1485 may facilitate slidable advancement of the stimulation portion 1482 in the lateral orientation LT by which a length of the stimulation portion 1482 (or portion of a stimulation lead body) may be inserted and advanced, via an implant-access incision, within a patient’s body to become positioned at an implant location in stimulating relation to a target tissue (e.g., target nerve portion, target muscle portion, and / or neuromuscular junction) to increase or maintain upper airway patency. In addition, the angled tines 1485 help to maintain longitudinal stability of the stimulation portion at the implant location relative to target tissue.

[0411] FIG. 25F is a diagram 1490 including a top plan view like that of FIGS. 25D-25E schematically representing an example stimulation portion 1491 comprising at least some of substantially the same features and attributes as the stimulation portion 1471 of FIG. 25C-25D, except with the addition of at least some tines 1492A, 1492B (like tines 1475) arranged in at angle like tines 1485 in FIG. 25E with some tines (e.g., 1492A) oriented divergently from some tines (e g., 1492B). Among other aspects, this example arrangement of providing some of the tines 1492A, 1492B at angle (like angle lambda A in FIG. 25E) but in different orientations may provide a more robust fixation in some implementations by providing some back-out resistance in divergent orientations.

[0412] FIG. 25G is a diagram 1493A including a top plan view like that of FIGS. 25D-25E schematically representing an example stimulation portion 1493B comprising at least some of substantially the same features and attributes as the stimulation portion 1471 of FIG. 25C-25D, except with tines 1494 (like tines 1475) arranged in a staggered relationship in a lateral insertion orientation (LT), such that a length of some of the tines 1494 are offset from each other in the circumferential orientation. Among other aspects, this example arrangement of tines may provide a more robust fixation in some implementations by providing more variability in anchor points in both a circumferential orientation (along or parallel to line B) and longitudinal 124 orientation (along or parallel to line A). In some such examples, the example anchor arrangement may inhibit or prevent longitudinal migration of the stimulation portion 1493B, which sometimes may be referred to as “lead ratcheting” or “inch worming.” Similarly, the example anchor arrangement may inhibit or prevent lateral migration of the stimulation portion 1493B.

[0413] FIG. 25H is a diagram 1495 including a top plan view like that of FIGS. 25D-25E schematically representing an example stimulation portion 1496 comprising at least some of substantially the same features and attributes as the stimulation portions of FIGS. 25C-25D, except with tines 1497A, 1497B (like tines 1492A, 1492B in FIG. 25F) arranged in at angle (like angle lambda A in FIG. 25E) but in a divergent orientation relative to each other. Among other aspects, this example arrangement of tines may provide a more robust fixation in some implementations by providing some back-out resistance in divergent orientations.

[0414] In some examples, an anchor structure for a stimulation portion (e.g., lead body, stimulation element) of various examples of the present disclosure and / or of a housing of an IMD (e.g., implantable pulse generator, implantable sensor, and the like) in at least some of the examples of FIGS. 1A-22B may comprise varying combinations of the features and attributes of the example implementations of FIGS. 25C-25H.

[0415] Moreover, in some examples, a stimulation portion may be implemented comprising a fixation structure comprising at least some of substantially the same features of the fixation structures of FIGS. 25C-25H combined with at least some of substantially the same features of the anchor structures of at least FIGS. 25A-25B.

[0416] FIGS. 26A-26C are a series of diagrams schematically representing various example anchor arrangements by which the stimulation portions, housings (throughout FIGS. 1A-22B) may be secured relative to target tissues and / or surrounding non-target tissues. The various example anchor arrangements in FIGS. 26A-26C also may comprise example implementations by which other stimulation portions, stimulation elements, housings, etc. throughout various examples of the 125 present disclosure may be secured, fixed, etc. relative to target tissues and / or surrounding non-target tissues.

[0417] As previously noted in association with previously described examples of the present disclosure, various type of anchors such as selectively deployable tines, barbs, etc. may be provided as part of the stimulation electrode arrangements.

[0418] As shown in FIG. 26A, in some examples, one anchor structure 2963 may comprise a plurality of anchor portions 2967, each of which comprise a plurality of anchor elements 2968. In some examples, each anchor portion 2967 may comprise at least some of substantially the same features and attributes as the example anchor portions described in association with at least 23A-25B (and / or optionally tines in FIGS. 25C-25H) in which a plurality of anchor elements are configured to engage surrounding tissues (e.g., target tissues and / or non-target tissues) to secure the stimulation portion (and / or housing) generally and to secure the contact electrodes 2056 into stimulating relation to the target tissues such as nerve portions, muscle portions, combinations of nerve portions and muscle portions, neuromuscular junctions of nerve portions and muscle portions, and / or combinations thereof.

[0419] As shown in the diagram 2950 of FIG. 26A, the various anchor portions 2967 are located on the stimulation surface 2053A of the stimulation electrode arrangement 2052A (which may be on an external surface of a housing of an IMD in some examples) and interposed between adjacent contact electrodes 2056 and in some examples, also may be located on the outer ends of the plurality of contact electrodes 2056, such as shown in FIG. 26B. In this configuration, the anchor portions 2967 act to engage target tissues and / or non-target tissues immediately adjacent to the contact electrodes 2056 to facilitate engagement of the contact electrodes 2056 in stimulating relation to the target tissues.

[0420] As shown in the diagram 3000 of FIG. 26B, in some example arrangements, anchor portions 2967 are located on the ends 2059A, 2059B (and / or side edges) of the body 2054 of the stimulation portion 2052A but are omitted from the locations between adjacent contact electrodes 2056. In some such examples, this configuration may enhance engagement of the contact electrodes 2056 with the surrounding target tissues and non-target tissues while still providing anchor portions in close proximity to the contact electrodes 2056. In some examples, this configuration may be desirable in example stimulation portions in which contact electrodes 2056 are flush (or have a low profile) relative to surface 2053A because the absence of anchor portions 2967 between contact electrodes 2056 may facilitate more direct engagement of the contact electrodes 2056 with the target tissues.

[0421] As shown in the diagram 3050 of FIG. 26C, in some examples anchor portions 2967 may be located on a non-stimulation surface 2053B (e.g., a back side) of the stimulation portion 2052A (and / or housing of an IMD) while some anchor portions 3067 may be located on the stimulation surface 2053A or omitted from the stimulation surface 2053A. The anchor portions 3067 on the non-stimulation surface 2053B may enhance securing the stimulation portion 2052A relative to surrounding non-target tissues. For example, upon closing an implant-access incision, anchor portions 2967 on the non-stimulation surface 2053B may engage more superficially-located tissues above the stimulation portion 2052A, thereby providing additional fixation.

[0422] While FIG. 26C shows non-stimulation surface 2053B partially covered by anchor portions 2967, it will be understood that in some examples, the entire (or substantially the entire) non-stimulation surface 2053B may be covered by anchor portions 2967.

[0423] As further shown in FIG. 26C, in some examples the anchor portions 3067 may comprise a thickness T3 (e.g., height) which is less than a distance T4 (e.g., height) by which contact electrodes 2056 may protrude from first surface 2053A such that the anchor portions 3067 may enhance securing the stimulation portion 2052A but have a low profile to also help facilitate robust engagement of the contact electrodes 2056 with the target tissues. In some examples, the anchor portions 2967 in the example of FIG. 26C may have a thickness T5 (e.g., height) which is substantially thicker than (e.g., greater than) the low profile thickness T3 (e.g., height) of the anchor portions 3067 so that anchor portions 2967 (on the non- 127 stimulation surface 2053B) may provide for more aggressive engagement of surrounding tissues.

[0424] In some examples, the various anchor portions (e.g., 2967, 3067) of FIGS. 26A-26C, and / or the anchor portions 4017 of FIGS. 27Aand 27D may comprise (or may sometimes be referred to as) anchor pads.

[0425] FIG. 27A is a diagram 4050 including a top plan view schematically representing an example device (and / or example method) including a stimulation portion 2052A (e.g., stimulation electrode arrangement) comprising an array of anchor portions 4017 distributed in a pattern spaced apart from each other on a first surface 2053A (e.g., stimulation surface) of the stimulation portion 2052A, with at least some of the various anchor portions 4017 interposed between adjacent contact electrodes 2056 such that the anchor portions 4017 are spaced apart from each other in a first orientation parallel to a length (e.g., a longitudinal axis LA) of the body 2054 of the stimulation portion 2052A. The anchor portions 4017 also are spaced apart from each other in a second orientation (SO) perpendicular to the first orientation, with such rows 4019 of anchor portions extending generally parallel to a length of the contact electrodes 2056. In some examples, each anchor portion 4017 comprises a plurality of anchor elements, which comprise at least some of substantially the same features and attributes as the anchor portions, anchor elements, etc. as described in association with at least FIGS. 23A-25B in which a plurality of anchor elements are configured to engage surrounding tissues (e.g., target tissues and / or non-target tissues) to secure the stimulation element generally and to secure the contact electrodes 2056 into stimulating relation to the target tissues such as nerve portions, muscle portions, combinations of nerve portions and muscle portions, neuromuscular junctions of nerve portions and muscle portions, and / or combinations thereof. In some examples, these anchor portions may be referred to as anchor pads.

[0426] FIG. 27B is a diagram 4075 including a top plan view schematically representing an example device (and / or example method) including a stimulation portion 2052A (e.g., stimulation electrode arrangement) comprising an array 4076 of anchor portions 4077 distributed in a pattern of columns spaced apart from each other on an opposite second surface 2053B (e.g., non-stimulation surface) of the stimulation element 2052A, with at least some of the various anchor portions 4077 spaced apart from each other in a second orientation (SO) perpendicular to a length (e.g., a longitudinal axis LA) of the body 2054 of the stimulation portion 2052A. Each anchor portion 4077 extends generally perpendicular to a length of the contact electrodes 2056 and extends generally parallel to a length (L2) of the body 2054 of the stimulation portion 2052A. In some examples, the anchor portions 4077 may comprise at least some of substantially the same features and attributes as anchor portions 4017 of the example arrangement in FIG. 27A, except for comprising a different shape, size, and / or orientation.

[0427] FIG. 27C is a diagram 4085 including a top plan view schematically representing an example device (and / or example method) including a stimulation portion 2052A (e.g., stimulation electrode arrangement) comprising an array 4086 of anchor portions 4087 distributed in a pattern spaced apart from each other in a generally parallel relationship on an opposite second surface 2053B (e.g., nonstimulation surface) of the stimulation portion 2052A. In one aspect, the anchor portions 4087 may sometimes be referred to as extending diagonally across the body 2054 of the stimulation portion 2052A. In one aspect, in this diagonal configuration, the various anchor portions 4087 extend in long strips which may enhance securing the stimulation portion in (or generally parallel to) both a major axis orientation (e.g., lengthwise orientation, along longitudinal axis LA) and a minor axis orientation (e.g., transverse orientation SO) of the body 2054 of the stimulation portion 2052A. In some examples, the anchor portions 4087 may comprise at least some of substantially the same features and attributes as anchor portions 4077 of the example arrangement in FIG. 27B, except for comprising a different shape, size, and / or orientation.

[0428] FIG. 27D is a diagram 4090 including a top plan view schematically representing an example stimulation portion 2092A comprising at least some of substantially the same features and attributes as the stimulation portion 2052A (and / or housing of an IMD) of FIG. 27A (and / or 27B, 27C), except further comprising an array 4093 of anchor portions 4094 located on a periphery or outer side edge 4092 of the body 2054 of the stimulation portion 2092A. In some examples, the anchor portions 4094 may comprise at least some of substantially the same features and attributes as anchor portions (e.g., 4017, 4077, etc.) of the example arrangement in FIGS. 27A, 27B, 24A, 24B, etc., respectively, except for comprising a different shape, size, and / or orientation as represented by FIG. 27D.

[0429] In some examples, the respective anchor portions 4094 are spaced apart from each other about the periphery 4092 of body 2054, which may provide a desired combination of slidability for initial positioning and of fixation once the stimulation portion 2092A (and / or housing of IMD) has been maneuvered into a location of chronic implantation. However, in some examples, the respective anchor portions 4094 are provided with little or no spacing between respective anchor portions 4094 such that the periphery 4092 may be considered to comprise a continuous or substantially continuous anchor portion.

[0430] In one aspect, in some examples the example arrangement periphery-located anchor portions 4094 of FIG. 27D may enhance anchoring within or among certain types of tissues while potentially lessening an amount of the surface area of other portions (e.g., 2053A, 2053B) of a body 2054 to be partially covered with some anchor portions. In another aspect, in some examples such arrangements may enhance anchoring for certain orientations (e.g., anterior-posterior, superior-inferior, medial-lateral) in view of a direction, orientation, etc. in which muscle portions of the target tissues (or surrounding non-target tissues) may move.

[0431] FIG. 27E is a diagram 4300 including a top plan view of an example flexible connector segment 4306 which may comprise at least some of substantially the same features and attributes as (or comprise an example implementation of) one of the previously described, flexible connector segments (forming part of a lead body and / or connecting multiple stimulation portions) or distal lead segments supporting a stimulation portion 2052A, while also comprising an anchor structure 4320 extending along a length of the flexible connector segment 4306. 130

[0432] As shown in FIG. 27E, the anchor structure 4320 forms a helical pattern on an exterior surface 4312 of the flexible connector segment 4306, with the anchor structure 4320 comprising anchor portions 4322 and anchor portions 4323 (shown in dashed lines to represent an opposite side of the flexible connector segment 4306).

[0433] In some examples, the anchor portions 4322 and the anchor portions 4323 may be spaced apart from each other by some distance, while in some examples, the anchor portions 4322 and anchor portions 4323 form part of a single, continuous anchor structure. In some such examples, this anchor structure may comprise (or may sometimes be referred to as) a single continuous anchor strip which wraps about an outer surface (periphery) of the flexible connector segment 4306 (or lead body).

[0434] In some examples, each anchor portion comprises a plurality of anchor elements, which comprise at least some of substantially the same features and attributes as the anchor portions, anchor elements, etc. as described in association with at least 23A-25B (and / or fixation elements in FIGS. 25C-25H in some examples) in which a plurality of anchor elements are configured to engage surrounding tissues (e.g., target tissues and / or non-target tissues) to secure the flexible connector segment (or distal lead segments) relative to surrounding tissues. This arrangement also acts to secure associated stimulation elements relative to the target tissues such as nerve portions, muscle portions, combinations of nerve portions and muscle portions, neuromuscular junctions of nerve portions and muscle portions, and / or combinations thereof.

[0435] In considering the various anchor portions described throughout the examples of at least FIGS. 1A-27E, it will be understood that anchor portions may be located on just the stimulation portions (e.g., stimulation electrode arrangements), on just the housing of IMDs, on just the flexible connector segments (which may form part of a lead body), on just the distal lead segments, or on some of each of the stimulation portions, housings, and the flexible connector segments (or distal lead segments).

[0436] FIG. 28 is a flow diagram schematically representing an example method 2800 for applying electrical stimulation to a patient. In some examples, the method 2800 may be implemented using the IMDs and tools described and illustrated with reference to FIGS. 1A-27E and 29-33. At 2802, method 2800 includes implanting a medical device within a patient (e.g., via tool 2010 of FIG. 22A). In some examples, implanting the medical device includes implanting the medical device within a head-and-neck region of the patient. At 2804, method 2800 includes applying electrical stimulation to tissue of the patient via a stimulation element (e.g., 308 of FIG. 2A or 2C, 510 of FIGS. 4A-6B, or678a-678c of FIGS. 11A-11C) within a housing (e.g., 302 of FIGS. 2A-2D, 502 of FIGS. 4A and 4B, 522 of FIGS. 5A and 5B, 542 of FIG. 6A, 562 of FIG. 6B, 582a-582c of FIGS. 7A-7C, 672a-672c of FIGS. 11 A-11C, 702 of FIGS. 12A-12E, 732 of FIGS. 13A-13E, 762 of FIGS. 14A-14E, 802 of FIGS. ISA-ISE, 832 of FIGS. 16A-16E, 862 of FIGS. 17A-17E, 902 of FIGS. 18A-18E, 932 of FIGS. 19A-19E, or 962 of FIGS. 20A-21) of the medical device. In some examples, applying the electrical stimulation includes applying the electrical stimulation to an upper airway patency-related tissue of the patient.

[0437] In some examples, implanting the medical device includes fixing the housing to a large muscle belly of a mylohyoid muscle for applying electrical stimulation to a hypoglossal nerve. In some examples, implanting the medical device comprises fixing the housing to a large muscle belly of a sternocleidomastoid muscle for applying electrical stimulation to an internal superior lary...

Claims

1. An implantable medical device comprising:a power element;a stimulation element and / or a sensor to sense physiologic information of a patient; anda housing enclosing the power element and the stimulation element and / or the sensor, the housing configured to be implanted within a head-and-neck region of the patient.

2. The implantable medical device of claim 1, further comprising:a wireless communication portion to receive power, data, and / or control signals.

3. The implantable medical device of claim 2, wherein the housing encloses at least a portion of the wireless communication portion.

4. The implantable medical device of claim 1, further comprising:a lead coupled to the stimulation element and / or the sensor; anda wireless communication element arranged on the lead to receive power, data, and / or control signals.

5. The implantable medical device of claim 1, further comprising:a control portion including a therapy manager to control the stimulation element based on at least control information and the sensed physiologic information to apply electrical stimulation to an upper airway patency-related tissue of the patient.1556. The implantable medical device of claim 1, wherein the housing comprises at least one of a thermoplastic material, a thermoset material, or a blend polymer material.

7. The implantable medical device of claim 1, wherein the housing comprises polyetheretherketone (PEEK), liquid-crystal polymer (LCP), polyether ketone (PEK), polypropylene, polycarbonate, polysulfone (PSU), or epoxy.

8. The implantable medical device of claim 1, wherein the housing comprises a first portion comprising a metal and a second portion comprising silicone, PEEK, polysulfone, or a ceramic.

9. The implantable medical device of claim 1, wherein the housing comprises a first portion comprising a metal and a second portion comprising at least one of a thermoplastic material, a thermoset material, or a blend polymer material.

10. The implantable medical device of claim 8 or 9, wherein a wireless communication element is directly adjacent to the second portion of the housing.

11. The implantable medical device of claim 10, wherein the first portion comprises a first outer wall of the housing and the second portion comprises a second outer wall of the housing opposite to the first outer wall, andwherein the first outer wall comprises a planar first segment, a planar second segment at an obtuse angle relative to the first segment, and a curved third segment connecting the first segment to the second segment.

12. The implantable medical device of claim 1, wherein the power element and the stimulation element and / or the sensor are overmolded by a single material to form the housing.15613. The implantable medical device of claim 1, wherein the power element and the stimulation element and / or the sensor are overmolded by a first material to form an inner housing portion, and the inner housing portion is overmolded or coated by a second material different from the first material to form an outer housing portion.

14. The implantable medical device of claim 1, wherein the housing comprises a first portion and a second portion welded or adhered to the first portion.

15. The implantable medical device of claim 1, further comprising:a wireless communication element comprising an antenna wrapped around the power element to form three orthogonal coils.

16. The implantable medical device of claim 1, further comprising:a wireless communication element comprising a set of trace antennas to generate three orthogonal fields.

17. The implantable medical device of claim 1, further comprising: a wireless communication element comprising a chip antenna.

18. The implantable medical device of claim 1, wherein the sensor comprises at least one of an accelerometer, a gyroscope, a piezoelectric sensor, or a microphone.

19. The implantable medical device of claim 1, wherein the sensor is configured to detect snoring.

20. The implantable medical device of claim 1, wherein the sensor is configured to detect airflow.15721. The implantable medical device of claim 1, wherein the sensor is configured to sense respiration.

22. The implantable medical device of claim 1, wherein the power element comprises a solid-state battery.

23. The implantable medical device of claim 22, wherein the solid-state battery conforms to a shape of the housing.

24. The implantable medical device of claim 5, further comprising: a silicon interposer electrically intercoupling the sensor, the stimulation element, and the control portion.

25. The implantable medical device of claim 1, wherein the housing comprises:a convex face portion;a first anchor wing coupled to a first side of the convex face portion for fixation of the housing within the patient via at least one first suture; anda second anchor wing coupled to a second side of the convex face portion opposite to the first side, the second anchor wing for fixation of the housing within the patient via at least one second suture.

26. The implantable medical device of claim 25, wherein the housing is configured for fixation to a large muscle belly.

27. The implantable medical device of claim 26, wherein the large muscle belly comprises a mylohyoid muscle for applying electrical stimulation to a hypoglossal nerve or a sternocleidomastoid muscle for applying electrical stimulation to an internal superior laryngeal nerve, an infrahyoid muscle (IHM)-innervating nerve, or a phrenic nerve.15828. The implantable medical device of claim 1, wherein the housing comprises: a concave face portion; andat least one suture trench arranged on a surface of the housing.

29. The implantable medical device of claim 28, wherein the at least one suture trench is arranged on a first surface of the housing opposite from the concave face portion.

30. The implantable medical device of claim 28, further comprising: a plurality of suture anchors extending around at least a portion of the housing for fixation of the housing within the patient via a plurality of sutures.

31. The implantable medical device of claim 1, wherein the housing comprises: a face portion; andat least one through hole extending through the face portion for fixation of the housing within the patient via at least one suture or at least one screw.

32. The implantable medical device of claim 28, wherein the housing is configured for fixation to a tendon or a narrow muscle belly.

33. The implantable medical device of claim 32, wherein the tendon or the narrow muscle belly comprises a digastric tendon for applying electrical stimulation to a hypoglossal nerve or an omohyoid muscle for applying electrical stimulation to an infrahyoid muscle (IHM)-innervating nerve ora phrenic nerve.

34. The implantable medical device of claim 1, wherein the housing comprises: an enclosure including an arcuate shaped face portion to engage anchoring tissue;a first anchor wing coupled to a first side of the enclosure for fixation of the housing within the patient via a first fastener;159a second anchor wing coupled to a second side of the enclosure opposite to the first side for fixation of the housing within the patient via a second fastener;a third anchor wing coupled to a third side of the enclosure extending between the first side and the second side for fixation of the housing within the patient via a third fastener; anda fourth anchor wing coupled to a fourth side of the enclosure opposite to the third side for fixation of the housing within the patient via a fourth fastener.

35. The implantable medical device of claim 34, wherein the arcuate shaped face portion comprises at least one protrusion and at least one recess juxtaposed in a configuration for fixation to the anchoring tissue for applying electrical stimulation to an upper airway patency-related nerve.

36. The implantable medical device of claim 1, wherein the housing comprises: an outer wall extending symmetrically along a major axis of the housing;at least one suture anchor coupled to the outer wall for fixation of the housing within the patient via at least one first suture; anda suture trench extending around an outer surface of the outer wall for fixation of the housing within the patient via at least one second suture.

37. The implantable medical device of claim 36, wherein the at least one suture anchor is arranged at an end of the outer wall.

38. The implantable medical device of claim 36, wherein the at least one suture anchor comprises a cross-shaped suture anchor.

39. The implantable medical device of claim 36, wherein the housing is configured for fixation to a muscle, a tendon, or other soft tissue.

40. The implantable medical device of claim 1, wherein the housing comprises:160a cuboid shaped first portion; anda cuboid shaped second portion coupled to the first portion and defining an end cap of the housing;a plurality of cross-shaped suture anchors coupled to an end face of the end cap;a first suture anchor coupled to a first side face of the end cap perpendicular to the end face; anda second suture anchor coupled to a second side face of the end cap opposite to the first side face.

41. The implantable medical device of claim 40, wherein the housing is configured for fixation to a muscle, a tendon, or other soft tissue.

42. The implantable medical device of claim 40, wherein a wireless communication element is directly adjacent to the second portion of the housing.

43. The implantable medical device of claim 42, wherein the second portion of the housing comprises a thermoplastic material, a thermoset material, or a blend polymer material.

44. The implantable medical device of claim 1, wherein the housing comprises: a first portion comprising a planar first major face;a second portion welded or adhered to the first portion such that the power element and the stimulation element and / or the sensor are enclosed between the first portion and the second portion;a plurality of first suture anchors coupled to a first side of the housing; anda plurality of second suture anchors coupled to a second side of the housing opposite to the first side.16145. The implantable medical device of claim 44, wherein a wireless communication element is directly adjacent to the second portion.

46. The implantable medical device of claim 45, wherein the first portion comprises a metal and the second portion comprises a thermoplastic material, a thermoset material, or a blend polymer material.

47. The implantable medical device of claim 1, wherein a length of the housing along a major axis of the housing is less than or equal to 4 centimeters.

48. The implantable medical device of claim 1, wherein a width of the housing along a minor axis of the housing is less than or equal to 2 centimeters.

49. The implantable medical device of claim 1, wherein the device is configured to be implanted via a single-incision surgical procedure.

50. The implantable medical device of claim 1, wherein the device is configured to be implanted via a transcutaneous delivery tool.

51. The implantable medical device of claim 1, wherein the device is configured to be implanted via a catheter delivery tool.

52. The implantable medical device of claim 1, further comprising:a plurality of fixation portions coupled to the housing for fixation of the housing within the patient.

53. The implantable medical device of claim 52, wherein the plurality of tines comprise a first tine coupled to a first side of the housing and a second tine coupled to a second side of the housing opposite to the first side.16254. The implantable medical device of claim 52, wherein the fixation portions comprise at least one of:tines, which comprise spring tines, bimetallic tines, or electromechanical tines; orat least one anchor portion comprising a plurality of anchor elements.

55. The implantable medical device of claim 1, further comprising: a lead coupled to the stimulation element; andat least one electrode arranged on the lead for applying electrical stimulation to an upper airway patency-related tissue of the patient.

56. A method comprising:implanting a medical device within a head-and-neck region of a patient; and applying electrical stimulation to an upper airway patency-related tissue of the patient via a stimulation element within a housing of the medical device.

57. The method of claim 56, wherein implanting the medical device comprises fixing the housing to a large muscle belly of a mylohyoid muscle for applying electrical stimulation to a hypoglossal nerve.

58. The method of claim 56, wherein implanting the medical device comprises fixing the housing to a large muscle belly of a sternocleidomastoid muscle for applying electrical stimulation to an internal superior laryngeal nerve, an infrahyoid muscle (IHM)-innervating nerve, ora phrenic nerve.

59. The method of claim 56, wherein implanting the medical device comprises fixing the housing to a narrow muscle belly of an omohyoid muscle for applying electrical stimulation to an infrahyoid muscle (IHM)-innervating nerve or a phrenicnerve.16360. The method of claim 56, wherein implanting the medical device comprises fixing the housing to a digastric tendon for applying electrical stimulation to a hypoglossal nerve.

61. The method of claim 56, wherein implanting the medical device comprises fixing the housing to a mandible for applying electrical stimulation to a hypoglossal nerve.

62. The method of claim 56, wherein implanting the medical device comprises fixing the housing to a muscle, a tendon, or other soft tissue via a suture anchor coupled to the housing.

63. The method of claim 56, wherein implanting the medical device comprises implanting the medical device through a single incision surgical procedure.

64. The method of claim 56, wherein implanting the medical device comprises guiding the device to an implant location using a transcutaneous delivery tool.

65. The method of claim 56, wherein implanting the medical device comprises guiding the device to an implant location using a catheter delivery tool.

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