SEGMENTED ELECTRODE FOR A SEGMENTED LEAD
CROSS RELATED REFERENCES.
[0001] This application is a PCT application that claims priority to and the benefit of U.S.
Provisional Patent Application No. 63/624,153 filed January 23, 2024, the entire contents of which is incorporated herein by reference.
FIELD OF INVENTION
[0002] The present disclosure is generally directed to nerve and/or brain stimulation and relates more particularly to a lead and electrode constructed for applying stimulation or for sensing responses to stimulation.
BACKGROUND
[0003] Implantable electrical stimulators may be used to deliver electrical stimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, urinary or fecal incontinence, sexual dysfunction, obesity, or gastroparesis. In general, an implantable stimulator delivers neurostimulation therapy in the form of electrical pulses. An implantable stimulator may deliver neurostimulation therapy via one or more leads that include electrodes located proximate to target tissues of the brain, the spinal cord, pelvic nerves, peripheral nerves, or the stomach of a patient. Hence, stimulation may be used in different therapeutic applications, such as deep brain stimulation (DBS), spinal cord stimulation (SCS), pelvic stimulation, gastric stimulation, or peripheral nerve stimulation. Stimulation also may be used for muscle stimulation, e.g., functional electrical stimulation (FES) to promote muscle movement or prevent atrophy.
[0004] Implantable medical leads carry electrodes that may be used to deliver electrical stimulation and/or sense electrical physiological signals. Different examples of implantable medical leads include cylindrical leads carrying ring electrodes or segmented electrodes and paddle style leads that carry electrode contacts. Paddle style leads may provide directional stimulation, but often require surgical implantation, although percutaneous implantation is possible. Cylindrical leads with ring or segmented electrodes may be implanted surgically or percutaneously. [0005] In general, implantable medical leads include one or more electrodes at or near a distal end of the lead, e.g., on a distal portion of the lead, which may be positioned proximate the patient tissue to be stimulated and/or from which the physiological signals are to be sensed. Implantable medical leads also include one or more connectors at or near a proximal end of the lead, e.g., on a proximal portion of the lead. The connectors are electrically connected to a respective one or more of the electrodes by one or more conductors within the body of the lead. The connectors may be electrically connected to circuitry within an implantable medical device, e.g., via a header of the implantable medical device and, in some cases, via a lead extension. In some cases, the proximal portion of the lead, including the connectors, may be inserted into a receptacle of the header or lead extension to mechanically and electrically connect the lead to the implantable medical device.
BRIEF SUMMARY
[0006] This disclosure includes techniques for the design, manufacture, and use of implantable medical leads including one or more segmented electrodes for inclusion with an implantable medical lead. Implantable medical leads including one or more segmented electrodes as described herein may be percutaneously implantable, and provide stimulation and/or sensing functionality when disposed on a distal portion of the lead. The implantable medical leads may include one or more connectors (e.g., on a proximal portion of the lead) that electrically connect the one or more electrodes to an implantable medical device via one or more conductors within the leads. Stimulation and/or sensing capabilities may be provided by a stimulation device, which is connectable to the one or more electrodes via the one or more conductors.
[0007] Example aspects of the present disclosure include: a segmented electrode, comprising: an insulator material formed in a substantially cylindrical configuration, the insulator material comprising a conductor lumen passing therethrough; and at least two metal electrode segments that are electrically insulated from one another by the insulator material, wherein each of the at least two metal electrode segments comprise an electrode segment outer surface that is exposed at an outer diameter of the segmented electrode, and wherein each of the at least two metal electrode segments comprise a conductor pathway that is centrally aligned with the conductor lumen and that exposes at least three metal surfaces in the conductor lumen.
[0008] In some embodiments, the at least three metal surfaces comprise an inner retainer surface of a t-post, a side retainer surface, and an outer retainer surface.
[0009] In some embodiments, a center of the conductor pathway is equidistance from the inner retainer surface, the side retainer surface, and the outer retainer surface. [0010] In some embodiments, a distance between the inner retainer surface and the side retainer surface is less than a width of the conductor lumen.
[0011] In some embodiments, the conductor lumen comprises a linear pathway extended through the insulator material.
[0012] In some embodiments, the insulator material comprises a stylet lumen that is substantially parallel with the conductor lumen.
[0013] In some embodiments, the at least two metal electrode segments comprise three metal electrode segments and wherein each of the three metal electrode segments comprise at least two conductor pathways.
[0014] In some embodiments, the conductor pathway comprises a non-circular cross-section and wherein the conductor lumen comprises a substantially circular cross-section.
[0015] According to another aspect, an implantable medical lead is provided, comprising: a stylet; [0016] one or more segmented electrodes supported by the stylet, wherein each of the one or more segmented electrodes comprises: an insulator material comprising a conductor lumen passing therethrough; and at least two metal electrode segments that are electrically insulated from one another by the insulator material, wherein each of the at least two metal electrode segments comprise an electrode segment outer surface that is exposed at an outer diameter of the one or more segmented electrodes, and wherein each of the at least two metal electrode segments comprise a conductor pathway that is centrally aligned with the conductor lumen and that exposes at least three metal surfaces in the conductor lumen; and an overmold material that substantially fixes a position of the one or more segmented electrodes relative to the stylet.
[0017] In some embodiments, the one or more segmented electrodes comprises a plurality of segmented electrodes.
[0018] In some embodiments, the insulator material comprises a stylet lumen passing therethrough that receives the stylet.
[0019] In some embodiments, the stylet lumen is substantially parallel with the conductor lumen.
[0020] In some embodiments, the at least three metal surfaces comprise an inner retainer surface, a side retainer surface, and an outer retainer surface.
[0021] In some embodiments, a center of the conductor pathway is equidistance from the inner retainer surface, the side retainer surface, and the outer retainer surface and wherein the inner retainer surface is part of a t-post that separates the conductor pathway from a second conductor pathway. [0022] According to another aspect, a system is provided, comprising: a stimulation device; and a lead electrically connectable with the stimulation device, wherein the lead comprises one or more segmented electrodes distributed at a distal end thereof, wherein each of the one or more segmented electrodes comprises: an insulator material comprising a conductor lumen passing therethrough; and at least two metal electrode segments that are electrically insulated from one another by the insulator material, wherein each of the at least two metal electrode segments comprise an electrode segment outer surface that is exposed at an outer diameter of the one or more segmented electrodes, and wherein each of the at least two metal electrode segments comprise a conductor pathway that is centrally aligned with the conductor lumen and that exposes at least three metal surfaces in the conductor lumen.
[0023] In some embodiments, the stimulation device comprises a circuit to provide stimulation signals to the one or more segmented electrodes via the lead.
[0024] In some embodiments, the stimulation device comprises a circuit to measure a response to stimulation signals received at the one or more segmented electrodes.
[0025] In some embodiments, the at least three metal surfaces comprise an inner retainer surface, a side retainer surface, and an outer retainer surface.
[0026] In some embodiments, a center of the conductor pathway is equidistance from the inner retainer surface, the side retainer surface, and the outer retainer surface and wherein the inner retainer surface is part of a t-post that separates the conductor pathway from a second conductor pathway.
[0027] In some embodiments, the stimulation device is implantable.
[0028] Any aspect in combination with any one or more other aspects.
[0029] Any one or more of the features disclosed herein.
[0030] Any one or more of the features as substantially disclosed herein.
[0031] Any one or more of the features as substantially disclosed herein in combination with any one or more other features as substantially disclosed herein.
[0032] Any one of the aspects/features/implementations in combination with any one or more other aspects/ features/ implementations .
[0033] Use of any one or more of the aspects or features as disclosed herein.
[0034] It is to be appreciated that any feature described herein can be claimed in combination with any other feature(s) as described herein, regardless of whether the features come from the same described implementation. [0035] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims. [0036] The preceding is a simplified summary of the disclosure to provide an understanding of some aspects of the disclosure. This summary is neither an extensive nor exhaustive overview of the disclosure and its various aspects, implementations, and configurations. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure but to present selected concepts of the disclosure in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other aspects, implementations, and configurations of the disclosure are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
[0037] Numerous additional features and advantages of the present disclosure will become apparent to those skilled in the art upon consideration of the implementation descriptions provided hereinbelow.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0038] The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the disclosure. The drawings simply illustrate preferred and alternative examples of how the disclosure can be made and used and are not to be construed as limiting the disclosure to only the illustrated and described examples. Further features and advantages will become apparent from the following, more detailed, description of the various aspects, implementations, and configurations of the disclosure, as illustrated by the drawings referenced below.
[0039] Fig. 1 illustrates an example of a system in accordance with aspects of the present disclosure;
[0040] Fig. 2 illustrates another example of a system in accordance with aspects of the present disclosure;
[0041] Fig. 3A provides a side view of one example lead in accordance with aspects of the present disclosure;
[0042] Fig. 3B provides a cross-sectional view of the lead illustrated in Fig. 3A;
[0043] Fig. 4 provides an isometric view of another example lead in accordance with aspects of the present disclosure; [0044] Fig. 5 provides a side view of another example lead in accordance with aspects of the present disclosure;
[0045] Fig. 6A provides an isometric view of an electrode in accordance with aspects of the present disclosure;
[0046] Fig. 6B provides a cross-sectional view of an electrode in accordance with aspects of the present disclosure;
[0047] Fig. 6C provides a magnified view of the electrode illustrated in Figs. 6A and 6B;
[0048] Fig. 7A provides an isometric view of a finished electrode in accordance with aspects of the present disclosure;
[0049] Fig. 7B provides a cross-sectional isometric view of the finished electrode illustrated in Fig. 7A;
[0050] Fig. 8A provides a top isometric view of another electrode in accordance with aspects of the present disclosure;
[0051] Fig. 8B provides a front view of the electrode illustrated in Fig. 8A;
[0052] Fig; 8C provides a bottom isometric view of the electrode illustrated in Fig. 8A; and [0053] Fig. 9 illustrates an example of method of manufacturing a lead in accordance with aspects of the present disclosure.
DETAILED DESCRIPTION
[0054] The features and techniques described herein are useful in types of medical device systems, which include implantable medical leads and implantable medical devices. For example, the features and techniques described herein may be used in systems with implantable electrical stimulation leads and implantable medical devices that deliver electrical stimulation therapy to a patient's brain (e.g., DBS). In another example, the features and techniques described herein may be used in systems with medical devices that deliver electrical stimulation therapy to a patient's heart (e.g., pacemakers, and pacemaker-cardioverter-defibrillators). As other examples, the features and techniques described herein may be embodied in systems that deliver other types of electrical stimulation therapy (e.g., SCS, peripheral nerve stimulation, pelvic nerve stimulation, gastric nerve stimulation or vagal nerve stimulation), stimulation of at least one muscle or muscle groups, stimulation of at least one organ such as gastric system stimulation, stimulation concomitant to gene therapy, and, in general, stimulation of any tissue of a patient.
[0055] In addition, while the examples shown in the figures include leads coupled at their proximal ends to a stimulation device (e.g., implantable medical device or IMD) located remotely from the electrodes, other configurations are also possible and contemplated. In some examples, a lead comprises a portion of a housing, or a member coupled to a housing, of stimulation device located proximate to or at the stimulation site (e.g., as a microstimulator). In other examples, a lead comprises a member at a stimulation site that is coupled by a lead extension to an IMD.
[0056] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example or implementation, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, and/or may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the disclosed techniques according to different implementations of the present disclosure). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a computing device and/or a medical device.
[0057] Before any implementations of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other implementations and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Further, the present disclosure may use examples to illustrate one or more aspects thereof. Unless explicitly stated otherwise, the use or listing of one or more examples (which may be denoted by “for example,” “by way of example,” “e.g.,” “such as,” or similar language) is not intended to and does not limit the scope of the present disclosure.
[0058] The terms proximal and distal are used in this disclosure with their conventional medical meanings, proximal being closer to the operator or user of the system, and further from the region of surgical interest in or on the patient, and distal being closer to the region of surgical interest in or on the patient, and further from the operator or user of the system.
[0059] Fig. 1 illustrates one example of a system 100 in accordance with aspects of the present disclosure. The system 100 is shown to include a stimulation device 112, which may be configured as an implantable medical device or as an external stimulation device. In other words, the stimulation device 112 may or may not be implanted inside of a patient 104. When not implanted in the patient 104, the stimulation device 112 may be carried by the patient 104 or worn by the patient 104 in a harness or similar type of garment.
[0060] In some embodiments, the stimulation device 112 may include an internal controller that delivers electrical signals via a lead 120 to one or more electrodes 128a, 128b. In some embodiments, the stimulation device 112 may be configured to communicate wirelessly or via a wired connection with a computing device 116. Computing device 116 may support programming functions associated with the stimulation device 112. Stimulation device 112 may include monitoring circuitry in electrical connection with the electrodes 128a, 128b of the lead 120.
[0061] As shown in fig. 1, the lead 120 may include a plurality of leads, where each lead includes a separate lead distal end 124a, 124b. A first distal end 124a of the lead 120 may include a first plurality of electrodes 128a and a second distal end 124b of the lead 120 may include a second plurality of electrodes 128b. The electrodes 128a, 128b may be in physical contact with anatomy of the patient 104. In the example of Fig. 1, the distal ends 124a, 124b are implanted in or near the patient’s 104 brain 108. In this configuration, the stimulation device 112 may deliver electrical energy or stimulation waveforms to the brain 108 via the electrodes 128a, 128b.
[0062] In addition to delivering stimulation to the brain 108, one or more electrodes in the electrodes 128a, 128b may be configured to receive or sense electrical responses to the stimulation applied by other electrodes. Thus, the stimulation device 112 may include stimulation circuitry that generates and transmits stimulation signals via the electrodes 128a, 128b and/or sensing circuitry that senses bioelectrical signals from one or more regions of the patient 104 anatomy (e.g., the brain 108 or nervous tissue).
[0063] In some embodiments, control circuitry of stimulation device 112 or another device (e.g., computing device 116) monitors the bioelectrical signal within anatomical element(s) of the patient 104 to assess neural activation responsive to stimulation provided by the stimulation device 112. Control circuitry of stimulation device 112 or another device (e.g., computing device 116) may control delivery of the electrical stimulation or other therapy to the anatomical element(s) according to programmed conditions, which are intended to treat a medical condition of the patient 104.
[0064] In some examples, the sensing circuitry of stimulation device 112 may receive the bioelectrical signal from the electrode(s) 128a, 128b or other electrodes positioned to monitor bioelectrical signal of the patient. Examples of the monitored bioelectrical signal include, but are not limited to, an EEG signal, an ECoG signal, an MEG signal, an ECAP signal, and/or a LFP signal sensed from within or about one or more regions of an anatomical element. [0065] According to example aspects of the present disclosure, stimulation device 112 may deliver therapy to any suitable portion of an anatomical element. In the example of Fig. 1, the stimulation device 112 is configured to manage a medical condition, such as a neurological disorder, by providing therapy to correct a brain 108 disorder and/or manage symptoms of a neurodegenerative brain 108 condition. In the example of Fig. 2, the stimulation device 112 is configured to deliver therapy on or near the patient’s 104 spinal cord 132. Specifically, the stimulation device 112 may be coupled to a lead 120 having a distal end 124 placed on or near the spinal cord 132 or a specific nerve branching from the spinal cord 132. Lead 120, for example, may be implanted near the spinal cord 132, nerves (e.g., a pudendal nerve, a splanchnic nerve, a sacral nerve, etc.), or any other nervous or muscle tissue that may be stimulated or from which physiological signals may be sensed. The stimulation device 112 may be, for example, an implantable neurostimulator that provides electrical signals to patient 104 via electrodes 128 located on a distal end 124 of lead 120. In some embodiments, the stimulation device 112 providing treatment at or near the spinal cord 132 may provide neurostimulation to treat symptoms of patient 104, such as pain, fecal or urinary incontinence, erectile dysfunction, kidney disorders, liver disorders, pancreatic disorders, or sexual dysfunction.
[0066] Although patient 104 is illustrates as a human patient, it should be appreciated that embodiments of the present disclosure are not so limited. For instance, aspects of the present disclosure may support applying the techniques described herein to other mammalian or nonmammalian non-human patients 104.
[0067] In the example shown in FIG. 6, stimulation device 154 may be implanted within a subcutaneous pocket below the clavicle of subject 148. In other embodiments, stimulation device 154 may be implanted within other regions of subject 148 (e.g., a subcutaneous pocket in the abdomen or buttocks of subject 148, proximate the cranium of subject 148, etc.). Implanted lead extension 156 is coupled to stimulation device 154 via a connector component (also referred to as a header). The connector component may include, for example, electrical contacts that electrically couple to respective electrical contacts on lead extension 156. The electrical contacts electrically couple the electrodes 150 carried by leads 157 to stimulation device 154.
[0068] In the example in which anatomical element is the brain 108 of the patient 104, DBS may be used to treat dysfunctional neuronal activity in the brain which manifests as diseases or disorders such as Huntington's Disease, Parkinson's Disease, or movement disorders. The exact reasons why electrical stimulation therapy is capable of treating such conditions of the brain is unknown, but symptoms of these diseases can be lessened or eliminated with electrical stimulation therapy. Certain anatomical regions of brain 108 are responsible for producing the symptoms of such brain disorders. As one example, stimulating an anatomical region, such as the Substantia Nigra, in brain 108 may reduce the number and magnitude of tremors experienced by patient 104. Other anatomical regions may include the subthalamic nucleus, globus pallidus interna, ventral intermediate, and zona inserta. Anatomical regions such as these are targeted by the clinician during the implantation of lead 120. In other words, the clinician may attempt to position the distal end 124 of lead 120, including the one or more electrodes 128a, 128b, as close to these regions as possible.
[0069] In some aspects, processing circuitry of system 100 (e.g., a processor of computing device 116 or a processor of stimulation device 112) may control delivery of electrical stimulation by activating electrical stimulation, deactivating electrical stimulation, increasing the intensity of electrical stimulation, or decreasing the intensity of electrical stimulation delivered to anatomical element in association with titrating electrical stimulation therapy. The processing circuitry (and/or control circuitry of the computing device 116 or the stimulation device 112) may support starting, stopping, and/or changing delivery of the therapy in any manner and based on any parameter or finding as discussed herein.
[0070] According to example aspects of the present disclosure, computing device 116 as a medical device may be a larger workstation or a separate application within another multi-function device, rather than a dedicated computing device. For example, the multi-function device may be a notebook computer, tablet computer, workstation, cellular phone, personal digital assistant or another computing device. The circuitry components of the computing device 116 and other devices described herein can be control circuitry as means for performing functions as described herein (e.g., receiving signals from stimulation device 112 via telemetry, measuring amplitude or power of the signals, calculating variance, assessing nervous tissue activation levels, etc.).
[0071] Referring now to Figs. 3 A, 3B, 4, and 5, various examples of leads 120 will be described in accordance with at least some embodiments of the present disclosure. Figs. 3A and 3B illustrate a first example of a distal end 124 of a lead 120. In the example of Figs. 3 A and 3B, the distal end 124 includes one or more electrodes 308, an overmold 304, one or more elongated conductors 316, and a stylet 324. The conductor(s) 316 may originate at a connector side 312, which opposes the tip 320 of the lead 120. The connector side 312 may correspond to a proximal side of the distal end 124 of the lead 120, meaning that the conductor(s) 316 originate from the connector side 312 and extend through the distal end 124 toward the tip 320. Some conductor among the plurality of conductors 316 may connect with and terminate at an electrode 308 closer to the connector side 312, whereas other conductors 316 may extend across the entire length of the distal end 124 to be connected to the last electrode 308 that is nearest the tip 320.
[0072] Each of electrodes 308 may correspond to a cylindrical conductive element that is part of a sub-assembly (e.g., a cylindrical or semi-cylindrical sub-assembly), which will be described in further detail herein. The electrode 308 sub-assemblies may be segmented to support multiple electrode segments at each electrode 308. Segmented electrodes 308 may be used to deliver a stimulation signal via one of the segments of an electrode 308, then sense a response to the stimulation signal via another one of the segments of the same electrode 308. In the example of Figs. 3 A and 3B, electrodes 308 provide an electrical connection between tissue or organs of a patient and stimulation device 112 via one or more elongated conductors 316 of lead 120. In some examples, conductive portions of electrodes 308 may be formed from a conductive biocompatible material such as a platinum alloy (e.g., 90% PT / 10% Ir), stainless steel, medical-grade steel, or other metal.
[0073] Overmold 304 is adjacent to and surrounds electrodes 308 and provides support and electrical isolation between each of electrodes 308. In some examples, overmold 304 is a hardenable organic polymeric material, which is injected into a mold containing the stylet 324, conductor(s) 316, and electrodes 308, and fills in the interstices of distal end 124. In some examples, after hardening the organic polymeric material to create overmold 304 at distal end 124, a portion of overmold 304 may be trimmed and/or removed to expose electrodes 308, such that electrodes 308 may have an electrical connection patient tissue. In other examples, outer surfaces of electrodes 308 may be adjacent to the mold, such that the outer surfaces of electrodes 308 remain exposed and require no trimming or removal of overmold material. In some examples, the hardenable organic polymeric material (“overmold material”) may be selected from a group consisting of polyurethanes, polyurethanes with surface-modifying end groups, polyurethane silicone block copolymers, silicones, fluoropolymers, fluoroelastomers, polyethylenes, and polyesters. In other words, overmold 304 exposes the cylindrical conductive elements of electrodes 308 while providing support and electrical isolation between electrodes 308, and protecting the interior of distal end 124 from external conditions.
[0074] Figs. 4 and 5 illustrate alternative configurations of a lead 120 according to at least some embodiments of the present disclosure. In the configuration of Fig. 4, the lead 120 comprises similar components as the lead 120 of Figs. 3A and 3B. The lead 120 of Fig. 4, however, comprises conductor(s) 316 that traverse the distal end 124 in a linear fashion as compared to the coiled conductor(s) 316 of Figs. 3 A and 3B. More specifically, the conductor(s) 316 arrive at the distal end 124 in a coiled configuration, but are then separated and straightened such that each conductor 316 extends toward the tip 320 in a substantially straight line. In particular, each conductor 316 transitions from being wrapped around the stylet 324 to travelling substantially parallel with the stylet 324. Providing each conductor 316 with such a linear configuration enables the conductor(s) 316 to be shorter as compared to the coiled configuration, thereby decreasing unwanted resistance and/or thermal issues that might be associated with longer conductor(s) 316. Providing conductor(s) 316 in the linear configuration may also make manufacturing the lead 120 simpler and less expensive.
[0075] The lead 120 of Fig. 4 also includes eight connectors 408 as compared to the four connectors 408of Figs. 3 A and 3B. It should be appreciated that a greater or lesser number of connectors 408may be included on a lead 120 without departing from the scope of the present disclosure. Moreover, one or more of the connectors 408may correspond to segmented or nonsegmented connectors 408. In some embodiments, certain connectors 408 (e.g., the first and last connectors 408 in the series) may be non-segmented connectors 408 having a full ring configuration whereas other connectors 408 (e.g., connectors 408 in the middle of the series) may be segmented connectors 408 having a plurality of exposed segments.
[0076] Fig. 5 illustrates a lead 120 configuration where the outermost electrodes correspond to a connector ring 404 and an electrode ring 508. The electrodes also include inner segmented electrodes 504, which are positioned between the connector ring 404 and electrode ring 508. The electrodes 504 may be similar or identical to electrodes 308In such a configuration, a single conductor 316 may terminate at the electrode ring 508 and connector ring 508, but multiple conductors 316 may terminate at the segmented electrodes 504. In an embodiment where the second and third electrodes 504 include two segments, then two conductors 316 may terminate at the second electrode 504 (e.g., one at each segment) and two more conductors 316 may terminate at the third electrode 504 (e.g., one at each segment). In an embodiment where the second and third electrodes 504 include two segments, then three conductors 316 may terminate at the second electrode 504 (e.g., one at each segment) and three more conductors 316 may terminate at the third electrode 504 (e.g., one at each segment).
[0077] Referring now to Figs. 6A thru 8, various configurations of segmented electrodes 308 will be described in accordance with at least some embodiments of the present disclosure. The segmented electrodes 308 depicted and described herein may be used in any of the leads 120 depicted and described herein. Additionally, electrodes 308 of different types may be used in different combinations on a single lead 120 without departing from the scope of the present disclosure. [0078] Figs. 6A, 6B, 6C, 7A, and 7B illustrate a first example of a segmented electrode 308. The electrode 308 may initially be constructed as shown in Figs. 6A, 6B, and 6C. After processing and when finally installed on a lead 120, the electrode 308 may be constructed as shown in Figs. 7A and 7B.
[0079] The electrode 308 is shown to have a cylindrical shape and to initially include a number of bumps 600, each of which have an outer bump surface 612. The electrode 308 also includes a number of electrode segment outer surfaces 620. Initially, each of the electrode segment outer surfaces 620 may be separated by a bump 600. During processing, the bumps 600 may be removed (e.g., subjected to etching, grinding, shaving, etc.), resulting in a finished electrode 308 as illustrated in Figs. 7A and 7B.
[0080] In some embodiments, the electrode 308 may also include an insulator material 602 that electrically separates each of the electrode segment outer surfaces 620 and helps to maintain electrical isolation between the segments of the electrode 308. The insulator material 602 may be constructed from a non-conductive material such as a polymer or the like. As a non-limiting example, the insulator material 602 may be constructed of a premolded and clear plastic material. The lumen may include a stylet lumen 708 configured to receive the stylet 324 and one or multiple conductor lumen 624 configured to receive one or more conductors 316. The shape and size of the conductor lumen 624 may depend on whether the conductor(s) 316 are formed in a straight or coiled configuration.
[0081] In some embodiments, conductor(s) 316 provide an electrical connection between the electrode segment outer surfaces 620 and the stimulation device 112. In some examples, a mandrel is included in the mold within a lumen defined by an electrode 308, and the insulator material 602 may be introduced into the mold between an interior surface of the electrode 308 and the mandrel. In this manner, the mandrel may define the interior surface of the insulator material 602, and accordingly the lumen 624, 708 of the electrode 308. As will be described in further detail herein, the conductive portions of the electrode 308 may be configured to retain a conductor 316 with two, three, or four points of metal contact. The conductor 316 may be physically held in place by specific geometries of the metal portions of the electrode 308 until the insulator material 602 is deposited within the metal portions of the electrode 308 and cured.
[0082] Elongated conductors 316 are a representation of insulated electrical conductors (e.g., wires) coupling one or more electrodes 308 to one or more connectors of the stimulation device 112. In some examples, each conductor 316 is contained within an insulator, which provides support and electrical isolation to one or more other conductors 316. Figs. 6B and 6C illustrate additional details of the metal geometry of the electrode 308, which create a conductor interlock 720 as shown in Fig. 7B.
[0083] As can be seen in Figs. 6B and 6C, the metal portion of the electrode 308 includes a plurality of bumps 600 having distinct bump outer surfaces 612. The bump outer surfaces 612 are offset from the electrode segment outer surface 620 by a first thickness Tl. Each bump outer surface 612 transitions to the electrode segment outer surface 620 at a notch 616. An interior cavity 636 of each bump 600 is configured to receive at least some of the insulator material 602. The interior cavity 636 may substantially align with a first diameter DI . To ensure that the electrode segment outer surfaces 620 are electrically isolated from one another, it may be desirable to grind or otherwise remove all of the bump 600 such that the maximum outer diameter of the electrode 308 is less than the first diameter DI, which means that some portions of the insulator material 602 in the interior cavity 636 are exposed at the outer surface of the electrode 308.
[0084] The interior metal geometry of the electrode 308 is also shown to include a number of wire-retaining features, which are configured and dimensioned to receive and hold a conductor 316 without aid of the insulator material 602 (e.g., in the absence of the insulator material 602). In some embodiments, the wire-retaining features may include a t-post 604, an outer retainer surface 608, and a side retainer surface 632. Each t-post 604 may divide two conductor pathways of an electrode segment. Each t-post 604 may also include two inner retainer surfaces 628. The outer retainer surface 608 may substantially align with a second diameter D2 of the electrode 308, which represents a minimum outer diameter of the electrode 308. In some embodiments, grinding of the electrode 308 to a diameter between the first diameter DI and the second diameter D2. In some embodiments, a thickness of the metal used to form the electrode 308 (e.g., the first thickness Tl) is less than the difference between the first diameter DI and the second diameter D2 to support manufacturing tolerances.
[0085] In the depicted embodiment, the electrode 308 is provided with three separate segments 716. In some embodiments, each of the three bumps 600 are removed to expose an insulator outer surface 712 to separate each of the three electrode segment outer surfaces 620. Each segment 716 is shown to include two conductor pathways separated by a t-post 604. A thickness of each t-post 604 may comprise a second thickness T2, which corresponds to a distance between two inner retainer surfaces 628 of the t-post 604. In some embodiments, each inner retainer surface 628 provided by the t-post 604 cooperates with an adjacent outer retainer surface 608 and an adjacent side retainer surface 632. A combination of three retainer surfaces may collectively form a conductor interlock 720, which can be used to secure and hold a conductor 316 in the absence of the insulator material 602. In some embodiments, the three retainer surfaces 608, 628, 632 are equidistance from a center 636 of the conductor pathway. A distance between a side retainer surface 632 and an inner retainer surface 628 may have a first width Wl, which is less than a diameter or width of a conductor 316. By providing three retainer surfaces 608, 628, 632 equidistance from the center 636 of the conductor pathway, the metal portion of electrode 308 can be formed and connected to a conductor 316 before the insulator material 602 is molded into the metal portion of the electrode 308. This geometry substantially reduces a construction cost associated with forming the electrode 308 as compared to a configuration where the conductor 316 cannot be independently held by the metal portion of the electrode 308.
[0086] As can be seen in Figs. 7A and 7B, each conductor pathway may align with a conductor lumen 704. In some embodiments, a center of a conductor lumen 704 may substantially align with the center 636 of the conductor pathway. In other words, the point within the conductor pathway that is equidistance from each of the three retainer surfaces may be substantially coincident with the center of the conductor lumen 704. This means that each of the retainer surfaces (e.g., three metal surfaces) are exposed within a conductor lumen 704 and physically contact a conductor 316 passing therethrough. The electrode 308 illustrated in Figs. 6A thru 7B is generally formable by a first forming step and then a grinding or similar material removal step.
[0087] The illustrative electrodes shown in Figs. 4-7 may be manufactured according to any suitable type of manufacturing process. For example, and without limitation, the electrodes may be manufactured using one or more of metal stamping, folding, crimping, machining, drawing, wire electrical discharge machining (EDM), and/or bending techniques.
[0088] Referring now to Figs. 8A thru 8C, an alternative configuration of an electrode 308 is shown and will be described in accordance with at least some embodiments. The electrode 308 of Figs. 8A thru 8C may be formed without requiring grinding or a subsequent material removal step. In particular, an electrode segment is illustrated, two or more of which may be used to create a segmented electrode 308 for a lead 120. In some embodiments, an electrode segment may be formed using metal stamping, folding, crimping, machining, drawing, wire electrical discharge machining (EDM), and/or bending techniques. Providing an electrode with two or more electrode segments as shown in Fig. 8A thru 8C may help avoid the process of grinding, which cannot generally be performed in a clean room. An electrode 308 formed with one, two, three, four, or more segments as shown may be provided on any suitable type of lead 120.
[0089] As illustrated, an electrode segment may include an outer surface 804, a first side 808, a second side 812, an optional slot 816, and a number of arms 820. In some embodiments, an electrode segment may include a number of arms 820 sufficient to create a plurality of gaps that interlock with the insulator material 602. Each arm 820 may be configured to connect with or physically contact a conductor 316 and provide electrical connectivity between the conductor 316 and the outer surface 804 of the electrode segment.
[0090] As shown in Fig. 8B, an electrode segment may be formed like a staple such that each arm 820 comprises an arm side surface 824 and an inward facing arm end 828. A relief 832 may be provided between an arm end 828 and the face of the electrode segment that opposes the outer surface 804. The relief 832 may be configured to receive and retain a polymer (e.g., polyurethane). A retention force may be provided from a ring locking into the polymer. In some embodiments, a conductor 316 may physically contact the inner-most surface of the arm 820 rather than being held in the relief 832. It should be appreciated that the electrode segment formed in this manner may be suitable for use with conductor(s) 316 having either a linear configuration or a coiled configuration. [0091] The slot 816 may be provided at a center point of the first side 808 and/or second side 812 of the electrode segment. In some embodiments, the slot 816 may be used during construction of the electrode segment to ensure alignment with the lead 120 and/or the stylet 324. The slot 816 may also be aligned with a gap between opposing arms 820. Functionally speaking, each outer surface 804 of an electrode segment as shown in Figs. 8A thru 8C may be similar to the electrode segment outer surfaces 620 of the electrode shown in Figs. 6A thru 7B.
[0092] Referring now to Fig. 9, an illustrative method of manufacturing a lead 120 with one or more segment electrodes 308 will be described in accordance with at least some embodiments of the present disclosure. The method begins by forming one or more segment electrodes (step 904). The process for forming the segment electrode(s) may depend upon the type of segmented electrode being used. For instance, the process of forming the segmented electrode(s) may include providing one or more metal portions of the electrode (which may initially be unitary or segmented). The process of forming the segmented electrode(s) may also include a grinding or material-removal step in which at least some portion (e.g., a bump 600) of the initially-formed electrode is removed to form discrete segments of the electrode 308. The process of forming the segment electrode(s) may also include stamping, folding, or crimping one or more sheets of metal to form one or more discrete segments of the electrode.
[0093] The method may also include positioning the electrode(s) at a distal end 124 of the lead 120 (step 912) and physically connecting one or more conductors 316 to one or more metal portions of the electrode (step 908). Although Fig. 9 illustrates the positioning step as occurring before the connecting step, it should be appreciated that these steps may be performed simultaneously or in an opposite order to the order depicted. For instance, conductor(s) 316 may first be connected to an electrode 308 before the electrode is positioned at the distal end 124 of the lead 120. The order in which the steps are performed may depend on the type of electrodes or segmented electrodes being used and/or the configuration of the conductors (e.g., a coiled configuration versus a linear configuration). One or both of steps 908 and 912 may also include providing the insulator material 602 in the electrode(s) and positioning the electrode(s) over the stylet 324.
[0094] The method may also include finalizing construction of the lead 120 (step 916). This step may include forming the overmold 304 around the electrodes 308 and fixing the position of the electrodes 308 relative to the stylet 324. This step may also include physically securing each electrode (or segment thereof) to one or more conductors 316 and testing the electrical connectivity between the electrodes 308, the conductors 316, and the stimulation device 112.
[0095] The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description, for example, various features of the disclosure are grouped together in one or more aspects, implementations, and/or configurations for the purpose of streamlining the disclosure. The features of the aspects, implementations, and/or configurations of the disclosure may be combined in alternate aspects, implementations, and/or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed aspect, implementation, and/or configuration. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred implementation of the disclosure.
[0096] Moreover, though the foregoing has included description of one or more aspects, implementations, and/or configurations and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative aspects, implementations, and/or configurations to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.
[0097] The phrases “at least one,” “one or more,” “or,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” “A, B, and/or C,” and “A, B, or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
[0098] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising,” “including,” and “having” can be used interchangeably.
[0099] The following are isslustrative of the techniques described herein.
[0100] Example 1 : A segmented electrode, comprising: an insulator material formed in a substantially cylindrical configuration, the insulator material comprising a conductor lumen passing therethrough; and at least two metal electrode segments that are electrically insulated from one another by the insulator material, wherein each of the at least two metal electrode segments comprise an electrode segment outer surface that is exposed at an outer diameter of the segmented electrode, and wherein each of the at least two metal electrode segments comprise a conductor pathway that is centrally aligned with the conductor lumen and that exposes at least three metal surfaces in the conductor lumen. [0100] Example 2: The segmented electrode according to example 1, wherein the at least three metal surfaces comprise an inner retainer surface of a t-post, a side retainer surface, and an outer retainer surface.
[0101] Example 3: The segmented electrode according to examples 1 or 2, wherein a center of the conductor pathway is equidistance from the inner retainer surface, the side retainer surface, and the outer retainer surface.
[0102] Example 4: The segmented electrode according to any preceding example, wherein a distance between the inner retainer surface and the side retainer surface is less than a width of the conductor lumen.
[0103] Example 5: The segmented electrode according to any preceding example, wherein the conductor lumen comprises a linear pathway extended through the insulator material.
[0104] Example 6: The segmented electrode according to any preceding example wherein the insulator material comprises a stylet lumen that is substantially parallel with the conductor lumen. [0105] Example 7: The segmented electrode according to any preceding example, wherein the at least two metal electrode segments comprise three metal electrode segments and wherein each of the three metal electrode segments comprise at least two conductor pathways. [0106] Example 8: The segmented electrode according to any preceding example, wherein the conductor pathway comprises a non-circular cross-section and wherein the conductor lumen comprises a substantially circular cross-section.
[0107] Example 9: An implantable medical lead, comprising:a stylet; one or more segmented electrodes supported by the stylet, wherein each of the one or more segmented electrodes comprises: an insulator material comprising a conductor lumen passing therethrough; and at least two metal electrode segments that are electrically insulated from one another by the insulator material, wherein each of the at least two metal electrode segments comprise an electrode segment outer surface that is exposed at an outer diameter of the one or more segmented electrodes, and wherein each of the at least two metal electrode segments comprise a conductor pathway that is centrally aligned with the conductor lumen and that exposes at least three metal surfaces in the conductor lumen; and an overmold material that substantially fixes a position of the one or more segmented electrodes relative to the stylet.
[0108] Example 10: The implantable medical lead according to example 9, wherein the one or more segmented electrodes comprises a plurality of segmented electrodes.
[0109] Example 11 : The implantable medical lead according to examples 9 or 10, wherein the insulator material comprises a stylet lumen passing therethrough that receives the stylet.
[0110] Example 12: The implantable medical lead according to example 11, wherein the stylet lumen is substantially parallel with the conductor lumen.
[0111] Example 13: The implantable medical lead according to examples 9 thru 12, wherein the at least three metal surfaces comprise an inner retainer surface, a side retainer surface, and an outer retainer surface.
[0112] Example 14: The implantable medical lead according to examples 9 thru 13, wherein a center of the conductor pathway is equidistance from the inner retainer surface, the side retainer surface, and the outer retainer surface and wherein the inner retainer surface is part of a t-post that separates the conductor pathway from a second conductor pathway.
[0113] Example 15: A system, comprising: a stimulation device; and a lead electrically connectable with the stimulation device, wherein the lead comprises one or more segmented electrodes distributed at a distal end thereof, wherein each of the one or more segmented electrodes comprises: an insulator material comprising a conductor lumen passing therethrough; and at least two metal electrode segments that are electrically insulated from one another by the insulator material, wherein each of the at least two metal electrode segments comprise an electrode segment outer surface that is exposed at an outer diameter of the one or more segmented electrodes, and wherein each of the at least two metal electrode segments comprise a conductor pathway that is centrally aligned with the conductor lumen and that exposes at least three metal surfaces in the conductor lumen.
[0114] Example 16: The system according to example 15, wherein the stimulation device comprises a circuit to provide stimulation signals to the one or more segmented electrodes via the lead.
[0115] Example 17: The system according to examples 15 or 16, wherein the stimulation device comprises a circuit to measure a response to stimulation signals received at the one or more segmented electrodes.
[0116] Example 18: The system according to examples 15 thru 17, wherein the at least three metal surfaces comprise an inner retainer surface, a side retainer surface, and an outer retainer surface.
[0117] Example 19: The system according to example 18, wherein a center of the conductor pathway is equidistance from the inner retainer surface, the side retainer surface, and the outer retainer surface and wherein the inner retainer surface is part of a t-post that separates the conductor pathway from a second conductor pathway.
[0118] Example 20 The system according to examples 15 thru 19, wherein the stimulation device is implantable.