Connections for electrodes in medical devices

Abstract

Devices, systems, and techniques include providing an insert between a feedthrough pin and electrode to enable electrical and mechanical connection between the feedthrough pin and electrode. In one example, a system includes an electrode defining an inner wall that defines an opening configured to accept an electrical connection device, an electrical connection device comprising an inner cylindrical wall defining an inner channel, wherein the electrical connection device is configured to be pressed into the opening, wherein at least a portion of the electrical connection device is configured to contact a portion of the inner wall of the electrode, and a feedthrough pin configured to be at least partially inserted into the inner channel of the electrical connection device.

Description

CONNECTIONS FOR ELECTRODES IN MEDICAL DEVICES

[0001] This application is a PCT application claiming priority to, and the benefit of, U.S. Provisional Patent Application Serial No. 63 / 639,395 filed on April 26, 2024, the entire contents of the application is incorporated herein by reference.TECHNICAL FIELD

[0002] The disclosure relates to medical devices, and more specifically to electrode connections to components of medical devices.BACKGROUND

[0003] Medical devices may be external or implanted and may be used to monitor patient signals such as cardiac activity, biological impedance and to deliver electrical stimulation therapy to patients via various tissue sites to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson’s disease, diabetes, epilepsy, urinary or fecal incontinence, sexual dysfunction, obesity, or gastroparesis and other conditions. In some examples, the medical devices may include one or more electrodes configured to sense electrical signals and / or deliver electrical stimulation to a patient.SUMMARY

[0004] In general, the disclosure describes systems, devices, and techniques for connecting electrodes for a medical device. Sensing circuitry and / or stimulation circuitry may be electrically connected to one or more electrodes. Connections between these structures may utilize wires, such as feedthrough pins, but the feedthrough pins and electrodes may have small dimensions which can be difficult to connect during manufacture. In addition, the materials of the feedthrough pin and the electrode may be different, and certain methods of connection, such as welding, may not be robust between certain materials. As described herein, an electrical connection device (e.g., an “insert”) can be placed between the electrode and the feedthrough pin to enable welding and securing the feedthrough pin. The insert may be constructed with specific features and / or dimensions that facilitate insertion into an opening defined by the electrode on small scales typical of implantable medical devices. In addition, the insert may be constructed with one or more materials that enable welding, material contact, or otherwise support electrical connection and physical connection between the feedthrough pin and the electrode.

[0005] In one example, a system includes: an electrode defining an inner wall that defines an opening configured to accept an electrical connection device; an electrical connection devicecomprising an inner cylindrical wall defining an inner channel, wherein the electrical connection device is configured to be pressed into the opening, wherein at least a portion of the electrical connection device is configured to contact a portion of the inner wall of the electrode; and a feedthrough pin configured to be at least partially inserted into the inner channel of the electrical connection device.

[0006] In another example, an electrical connection device includes: a distal portion defining a distal outer surface defining a first cross-sectional dimension, a proximal portion defining a proximal outer surface defining a second cross-sectional dimension larger than the first cross- sectional dimension, and an inner cylindrical wall that runs through at least a portion of the distal portion and a portion of the proximal portion, wherein the inner cylindrical wall defines an inner channel that is configured to accept a feedthrough pin therethrough.

[0007] The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. l is a conceptual diagram illustrating an example medical system of this disclosure that includes an implantable medical device (IMD) located near an ankle of a patient.

[0009] FIG. 2 is a block diagram illustrating an example medical device according to one or more techniques of this disclosure.

[0010] FIG. 3 is a top view of an example IMD.

[0011] FIG. 4 is a perspective view of an example IMD.

[0012] FIGS. 5 and 6 are perspective views of an example IMD with an electrode, insert, and feedthrough pin exposed.

[0013] FIG. 7 is a cross-sectional view of an example IMD with an electrode, insert, and feedthrough pin.

[0014] FIGS. 8 and 9 are cross-sectional side views of an example IMD with an electrode, insert, and feedthrough pin.

[0015] FIG. 10 is a perspective view of a front of an example electrode.

[0016] FIG. 11 is a perspective view of a back of an example electrode.

[0017] FIG. 12 is a perspective view of a bottom of an electrode, feedthrough pin, and insert.

[0018] FIG. 13 is a side view of an example insert.

[0019] FIGS. 14A and 14B are perspective views of an example insert.

[0020] FIG. 15 is an example technique for assembling a feedthrough pin with an insert and electrode.DETAILED DESCRIPTION

[0021] The disclosure describes systems, devices, and techniques for connecting electrodes for a medical device. Sensing circuitry and / or stimulation circuitry may be electrically connected to one or more electrodes. Connections between these structures of electrical devices may utilize wires, such as feedthrough pins, but the feedthrough pins and electrodes may have small dimensions which can be difficult to connect during manufacture. In addition, the materials of the feedthrough pin and the electrode may be different, and certain methods of connection, such as welding, may not be robust between certain materials.

[0022] In some examples of medical devices, one or more electrodes may be constructed of a 90 / 10 Platinum-Iridium alloy which may be used due to its low electrical impedance and biostability attributes. This Platinum-Iridium alloy can present an issue in manufacturing when the electrode should be permanently bonded to another material for electrical connection, such as a Niobium feedthrough pin. Niobium is a typical material for feedthrough pins due to its formability and corrosion resistance. When laser welded together, the Platinum-Iridium alloy and Niobium have significantly different melting temperatures, which can result in a brittle weld. Other interface designs (e.g., use of a mechanical crimp), can be used, but this mechanical connection may result in lower joint strength compared to welding.

[0023] As described herein, an electrical connection device (e.g., an “insert”) can be placed between the electrode and the feedthrough pin to enable welding and securing the feedthrough pin. The insert may be constructed with specific features and / or dimensions that facilitate insertion into an opening defined by the electrode on small scales typical of implantable medical devices. In some examples, this design can utilize a Titanium insert that is pressed into the Platinum-Iridium alloy electrode to then enable welding of the Titanium insert to the Niobium feedthrough pin.

[0024] Pressing processes, especially on micro-scale components, may require extremely tight tolerances in order to be manufacturable without damaging components. Example inserts described herein may also include features that allow for a wider tolerance range within each component. This wider tolerance may be accomplished via characteristics such as the insert may include a reduced diameter engagement section, which allows the insert to align itself to the inner diameter (ID) of the electrode that it is being pressed into. This improved alignment provided by the reduced diameter section (e.g., a smaller distal diameter than the proximal diameter) can aide the press process. In some examples, the insert design can include four flat face features between respective larger proximal portions along the length of the insert which limit the interference area between the insert and the electrode. These flat face features may have smaller radii thanadjacent sections which can enable greater design tolerance in inner and outer diameters of the mating components because the flat face features may not contact the electrode. The flat features can also provide locations for Platinum-Iridium material to move, or deform, during the press process which may reduce deformation of the inner channel within which the feedthrough pin can be placed. A laser weld can then take place between the titanium insert and the niobium feedthrough pin, which can create a robust solution.

[0025] FIG. 1 is a conceptual diagram illustrating an example medical system 100 of this disclosure that includes an implantable medical device located near an ankle of a patient. The example of system 100 in FIG. 1 includes implantable medical device (IMD) 110, recharger 150, and one or more external devices 112.

[0026] In some examples, recharger 150 may also be referred to as programmer 150, external recharging device 150 or external computing device 150. Recharger 150 as shown in FIG. 1 includes one or more coils, external transfer coil 126 and internal transfer coil 128. Recharger 150 may be used to program or adjust settings of IMD 110 and may also recharge an electrical energy storage device, such as a battery, of IMD 110 (not shown in FIG. 1). Recharger 150 may also communicate with one or more external devices 112. In other examples, recharger 150 may also include a mobile phone, tablet computer, a wearable computing device or similar computing device that includes processing circuitry configured to execute programming instructions to communicate with IMD 110 and / or external devices 112. Such a computing device may communicate with IMD 110 to adjust therapy and / or sensing parameters, download recorded data, and the other functions described in this disclosure. In some examples, such a computing device may additionally or alternatively be connected to external transfer coil 126 or include an internal transfer coil 128.

[0027] IMD 110 may include sensing circuitry configured to detect biological signals from the patient; electrical stimulation circuitry configured to deliver electrical stimulation to target tissue of the patient, communication circuitry, processing circuitry configured to control the operation of circuitry of IMD 110 and other circuitry (not shown in FIG. 1) configured to perform the functions described in this disclosure. IMD 110 may output the sensed data via communication circuitry (not shown in FIG. 1). In this disclosure, IMD 110 may referred to as medical device 110, implantable medical device (IMD) 110 or, in the example of a neurostimulation medical device, may be referred to as implantable neuro stimulator (INS) 110.

[0028] The communication circuitry may be configured to communicate with rechargers in system 100. In some examples, the communication circuitry may establish a first communication channel with recharger 150. In some examples, the communication circuitry may also establish a second communication channel with recharger 150. The communication circuitry of IMD 110, aswell as communication circuitry of recharger 150, external devices 112, and other devices of system 100 may be configured to establish the first communication channel and the second communication channel on the communication link using time division multiplexing. By multiplexing the information for each communication channel over the same communication link, the respective data for each communication channel may be interleaved together over time. IMD 110 may communicate via inductive communication or another protocol such as a wireless protocol (e.g., Bluetooth™, Bluetooth Low Energy (BLE), or a protocol using the Medical Implant Communication System (MICS) band) to a number of different instruments, such as, for example, an additional medical device, a patient programmer, a clinician programmer, a programming fob, or another device.

[0029] In the example of a rechargeable power source, the rechargeable power source of IMD 110 may include one or more capacitors, batteries, or other components, e.g., chemical, or electrical energy storage devices (not shown in FIG. 1). Example batteries may include lithium- based batteries, nickel metal-hydride batteries, or other materials. The rechargeable power source may be replenished, refilled, or otherwise capable of increasing the amount of energy stored after energy has been depleted. The energy received from transfer coil 116 may be conditioned and / or transformed by a charging circuit. The charging circuit may then send an electrical signal used to charge the rechargeable power source when the power source is fully depleted or only partially depleted.

[0030] Recharger 150 may be used to recharge the rechargeable power source within IMD 110 implanted in the patient. Recharger 150 may be a hand-held device, a portable device, or a stationary charging system. Recharger 150 may include components necessary to charge IMD 110 through tissue of the patient. Recharger 150 may include external transfer coil 126 and internal transfer coil 128. In other examples, recharger may only include internal primary coil 128 and omit the use of external transfer coil 126, may have multiple internal and external coils, or may omit internal transfer coil 128 and use external transfer coil 126.

[0031] Recharger 150 may include a housing to enclose operational components such as a processor, memory, user interface, telemetry circuitry, power source, and charging circuit configured to transmit energy to transfer coil 116 inside IMD 110 via external transfer coil 126 and / or internal transfer coil 128. Although a user may control the recharging process with a user interface of recharger 150, recharger 150 may alternatively be controlled by another device, e.g., an external programmer, a computing device of external devices 112, where such external device may include a tablet computer, laptop, or other similar computing device. In other examples, recharger 150 may be integrated with an external programmer, such as the patient programmer carried by the patient.

[0032] Recharger 150 and IMD 110 may utilize any wireless power transfer techniques that are capable of recharging the power source of IMD 110 when IMD 110 is implanted within the patient. In some examples, system 100 may utilize inductive coupling between primary coils (e.g., internal transfer coil 128 or external transfer coil 126) and secondary coils (e.g., transfer coil 116) of recharger 150 and IMD 110. In inductive coupling, internal transfer coil 128 (or external transfer coil 126) is placed near implanted IMD 110 such that internal transfer coil 128 (or external transfer coil 126) is aligned (e.g. coaxially) with transfer coil 116 of IMD 110. Recharger 150 may then generate an electrical current in internal transfer coil 128 based on a selected power level for charging the rechargeable power source of IMD 110.

[0033] When the primary coils (e.g., internal transfer coil 128 or external transfer coil 126) and the secondary coils (e.g., transfer coil 116) are aligned, or partially aligned, the electrical current in the primary coils may magnetically induce an electrical current in transfer coil 116 within IMD 110. Since the secondary coils are associated with and electrically coupled to the rechargeable power source, the induced electrical current may be used to increase the voltage, or charge level, of the rechargeable power source. Although inductive coupling is generally described herein, any type of wireless energy transfer may be used to transfer energy between recharger 150 and IMD 110.

[0034] External transfer coils 126 and internal transfer coil 128 may include a wound wire (e.g., a coil) (not shown in FIG. 1). The coil may be constructed of a wire wound in an in-plane spiral (e.g., a disk-shaped coil). In some examples, this single or even multi-layers spiral of wire may be considered a flexible coil capable of deforming to conform with a non-planar skin surface. The coil may include wires that electrically couple the flexible coil to a power source and a charging module configured to generate an electrical current within the coil. External transfer coil 128 may be external of the housing of recharger 150 such that external transfer coil 128 may be placed on the skin of the patient proximal to IMD 110. In some examples, external transfer coil 128 may be disposed on the outside of the housing or even within housing.

[0035] Either internal transfer coil 126 and / or external transfer coil 128 of system 100 may include a heat sink device (not shown in FIG. 1). In the example of system 100, recharger 150 is the power transmitting unit and IMD 110 is the power receiving unit. IMD 110 may be in a flipped or non-flipped position.

[0036] Recharger 150 may include a user interface to receive control inputs from a user, such as the patient, medical professional, or other caregiver. Recharger 150, and any computing device of system 100, may include a touch-screen user interface. The user interface of recharger 150 may also provide information to a user, including whether IMD 110 is ON and deliveringtherapy, whether recharger 150 is wirelessly communicating with IMD 110 and other information which recharger 150 may transfer or receive.

[0037] In some examples, recharger 150 may be configured to transfer data. Recharger 150 may be configured to transfer data by inductively linking the primary coils (e.g., internal transfer coil 128 or external transfer coil 126) and the secondary coils (e.g., transfer coil 116). In some examples, the primary coils and the secondary coils may be inductively linked when the primary coils and the secondary coils are aligned, or partially aligned, wherein the electrical current in the primary coils may magnetically induce an electrical current in transfer coil 116 within IMD 110. Data may be inductively transmitted between the primary coils and the secondary coils through frequency modulation of the current or amplitude modulation of the current. In some examples, the primary coils and / or the secondary coils may have a default optimization for receiving power. In some examples, the primary coils and / or the secondary coils may have a default optimization for receiving data. In some examples, the primary coils and / or the secondary coils may have a sufficient band pass range such that the coils are able to receive both power and data in their default tuning status. In some examples, the primary coils and / or the secondary coils may be tuned into a selective data receiving state wherein the default state changes from a power receiver default to a data receiver default for a temporary period of time. In some examples, the primary coils and / or the secondary coils may be tuned into a selective power receiving state wherein the default state changes from a data receiver default to a power receiver default for a temporary period of time.

[0038] The example of FIG. 1 is a side view of a patient’s leg showing IMD 110 as a leadless neurostimulation device near the ankle adjacent to tibial nerve 104. IMD 110 may be implanted through the patient’s skin and cutaneous fat layer via incision 102. In some examples, incision 102 may be relatively small (e.g., about one to three cm) to improve patient outcomes and decrease healing time. In some examples, incision 102 may be above tibial nerve 104 on a medial aspect of the patient’s ankle. While incision 102 is shown approximately horizontal to the length of tibial nerve 104, other incisions 102 or implantation techniques could be used according to physician preference such as a longitudinal to the length of tibial nerve 104 or at a 45 degree angle relative to tibial nerve 104. The example of FIG. 1 describes IMD 110 for tibial nerve stimulation. In other examples, the techniques of this disclosure may apply to other rechargeable devices, such as implantable neurostimulation system for use in spinal cord stimulation therapy, deep brain stimulation, as well as to other types of medical devices without limitation.

[0039] IMD 110 may be positioned adjacent to the region defined by flexor digitorum longus and soleus in which tibial nerve 104 is contained and implanted adjacent and proximal to a fascia layer. One or more electrodes of IMD 110 may face toward tibial nerve 104. Though not shownin FIG. 1, IMD 110 may also connect to one or more leads comprising one or more electrodes (not shown in FIG. 1).

[0040] IMD 110 may be constructed of any polymer, metal, or composite material sufficient to house the components of IMD 110. In this example, IMD 110 may be constructed with a biocompatible housing, such as titanium or stainless steel, or a polymeric material such as silicone or polyurethane, and surgically implanted at a site in patient near tibial nerve 104, in some examples, while in other examples, implanted near the pelvis, abdomen, or buttocks. The housing of IMD 110 may be configured to provide a hermetic seal for components, such as a rechargeable power source. In addition, the housing of IMD 110 may be selected of a material that facilitates receiving energy to charge the rechargeable power source.

[0041] During normal operation after implantation, an electrical stimulation signal may be transmitted between one or more electrodes through the fascia layer. The electrical signal may be used to stimulate tibial nerve 104 which may be useful in the treatment of overactive bladder (OAB) symptoms of urinary urgency, urinary frequency and / or urge incontinence, or fecal incontinence.

[0042] One type of therapy for treating bladder dysfunction includes delivery of electrical stimulation to a target tissue site within a patient to cause a therapeutic effect during delivery of the electrical stimulation. For example, delivery of electrical stimulation from IMD 110 to a target therapy site, e.g., a tissue site that delivers stimulation to modulate activity of tibial nerve 104, spinal nerve (e.g., a sacral nerve), a pudendal nerve, dorsal genital nerve, an inferior rectal nerve, a perineal nerve, or branches of any of the aforementioned nerves, may provide a therapeutic effect for bladder dysfunction, such as a reduction in frequency of bladder contractions. In some cases, electrical stimulation of tibial nerve 104 may modulate afferent nerve activities to restore urinary function.

[0043] FIG. 2 is a block diagram illustrating example components of the medical device as described above. Implantable medical device (IMD) 410 may be an example of IMD 110 of FIG. 1. IMD 410 of FIG. 2 is described as an implantable medical device, but the same functions, characteristics and techniques may also apply to other type of wearable or portable medical devices.

[0044] In the example illustrated in FIG. 2, IMD 410 includes housing 419 which may contain coil 416, power source 418, processing circuity 430, memory 432, therapy and sensing circuitry 434, communication circuitry 436, one or more sensors 437, recharge circuitry 438, temperature sensor 439, and encryption / decry ption circuitry 440. IMD 410 may be connected to electrodes 417. In other examples, IMD 410 may include a greater or a fewer number of components, e.g., in some examples, IMD 410 may not include sensors 437 or temperaturesensor 439. In general, IMD 410 may comprise any suitable arrangement of hardware, alone or in combination with software and / or firmware, to perform the various techniques described herein attributed to IMD 410 and processing circuitry 430, and any equivalents thereof.

[0045] Processing circuitry 430 of IMD 410 may be implemented as one or more processors, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. IMD 410 may include a memory 432, such as random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, comprising executable instructions for causing the processing circuitry 430 to perform the actions attributed to this circuitry.

[0046] Moreover, although processing circuitry 430, therapy and sensing circuitry 434, communication circuitry 436, recharge circuitry 438, and temperature sensor 439 are described as separate modules, in some examples, some combination of processing circuitry 430, therapy and sensing circuitry 434, communication circuitry 436, recharge circuitry 438, and temperature sensor 439 are functionally integrated. In some examples, processing circuitry 430, therapy and sensing circuitry 434, communication circuitry 436, recharge circuitry 438, and temperature sensor 439 correspond to individual hardware units, such as ASICs, DSPs, FPGAs, or other hardware units. For example, components of IMD 410 may be implemented as separate circuits in some examples. In other examples, two or more components of IMD 410 may be implemented on a single integrated circuit, e.g., including processing circuitry 430, memory 432, therapy and sensing circuitry 434, communication circuitry 436, and other components of IMD 410. In this disclosure, therapy, and sensing circuitry 434 may be referred to as therapy circuitry 434.

[0047] Memory 432 may store therapy programs or other instructions that specify therapy parameter values for the therapy provided by therapy circuitry 434 and IMD 410. In some examples, memory 432 may also store temperature data from temperature sensor 439, instructions for recharging rechargeable power source 418, thresholds, instructions for communication between IMD 410 and a recharger (such as recharger 150), or any other instructions required to perform tasks attributed to IMD 410. Memory 432 may be configured to store instructions for communication with and / or controlling one or more temperature sensors of temperature sensor 439. In various examples, memory 432 stores information related to determining the temperature of housing 419 and / or exterior surface(s) of housing 419 of IMD 410 based on temperatures sensed by one or more temperature sensors, such as temperature sensor 439, located within IMD 410.

[0048] For example, memory 432 may store programming settings such as parameters for electrical stimulation therapy output, e.g., magnitude, pulse width, and so on. Memory 432 may store parameters and other settings for the delivery of haptic stimulation. Settings may be individualized based on patient preference and / or patient physiology. For example, a stimulation intensity that is above the perception threshold for a first patient may be different than the stimulation intensity that may be above the perception threshold for a second patient. In some examples, a patient may find a particular frequency to be annoying or painful and therefore, may request a different frequency setting when receiving haptic stimulation as feedback.

[0049] Instructions stored at memory 432 when executed by processing circuitry 430 may determine whether a sensed bioelectrical signal is valid, such as and ECAP or other signal in response to an output electrical stimulation therapy event. Memory 432 may store programming instructions that when executed by processing circuitry 430 cause processing circuitry 430 to cause electrical stimulation circuitry therapy circuitry 434 to deliver electrical stimulation therapy to a target nerve of a patient. Memory 432 may also store instructions on encrypting and decrypting communications to be sent via communications circuitry 436 to a recharger (such as recharger 150), as well as instructions for establishing a communication channel over communication channels, as described above in relation to FIG. 1.

[0050] Therapy and sensing circuitry 434 may generate and deliver electrical stimulation under the control of processing circuitry 430. Therapy and sensing circuitry 434 may include stimulation generation circuitry configured to deliver electrical stimulation via any sets of electrodes 417. Therapy and sensing circuitry 434 may also output non-therapy stimulation, such as control pulses and haptic stimulation. In some examples, processing circuitry 430 controls therapy circuitry 434 by accessing memory 432 to selectively access and load at least one of the stimulation programs to therapy circuitry 434. For example, in operation, processing circuitry 430 may access memory 432 to load one of the stimulation programs to therapy circuitry 434. In such examples, relevant stimulation parameters may include a voltage amplitude, a current amplitude, a pulse rate, a pulse width, a duty cycle, or the combination of electrodes 417A, 417B, 417C, and 417D (collectively “electrodes 417”) that therapy circuitry 434 may use to deliver the electrical stimulation signal as well as sense biological signals. In other examples, IMD 410 may have more or fewer electrodes than the four shown in the example of FIG. 2. In some examples electrodes 417 may be part of or attached to a housing of IMD 410, e.g., a leadless electrode. In other examples, one or more of electrodes 417 may be part of a lead implanted in or attached to a patient to sense biological signals and / or deliver electrical stimulation, as described above in relation to FIG. 1. In any examples, electrodes 417, for example, may each be electrically coupled to a feedthrough pin via an insert as described herein.

[0051] In some examples, one or more electrodes 417 connected to therapy circuitry 434 may connect to one or more sensing electrodes 417, e.g., attached to housing of IMD 410. In some examples electrodes 417 may be configured to detect an evoked motor response caused by the electrical stimulation therapy event, or other bioelectrical signals such as ECAPs, impedance and so on.

[0052] IMD 410 also includes components to receive power to recharge rechargeable power source 418 when rechargeable power source 418 has been at least partially depleted. As shown in FIG. 2, IMD 410 includes coil 416 and recharge circuitry 438 coupled to rechargeable power source 418. Recharge circuitry 438 may be configured to charge rechargeable power source 418 with the selected power level determined by either processing circuitry 430 or an external charging device, such as external computing IMD 110 described above in relation to FIG. 1. Recharge circuitry 438 may include any of a variety of charging and / or control circuitry configured to process or convert current induced in coil 416 into charging current to charge power source 418. For example, recharge circuitry 438 may include measurement circuitry configured to determine a magnitude of current received by secondary coil 416, a magnitude of current delivered to power source 418, and other measurements. Recharge circuitry 438 may send such measurements to processing circuitry 430 to be used in system metrics, and sent to recharger (such as recharger 150) via communication circuitry 436.

[0053] Secondary coil 416 may include a coil of wire or other device capable of inductive coupling with a primary coil disposed external to the patient. Although secondary coil 416 is illustrated as a simple loop of in FIG. 2, secondary coil 416 may include multiple turns of conductive wire. Secondary coil 416 may include a winding of wire configured such that an electrical current may be induced within secondary coil 416 from a magnetic field. The induced electrical current may then be used to recharge rechargeable power source 418.

[0054] Recharge circuitry 438 may include one or more circuits that process, filter, convert and / or transform the electrical signal induced in the secondary coil to an electrical signal capable of recharging rechargeable power source 418. For example, in alternating current induction, recharge circuitry 438 may include a half-wave rectifier circuit and / or a full-wave rectifier circuit configured to convert alternating current from the induction to a direct current for rechargeable power source 418. The full-wave rectifier circuit may be more efficient at converting the induced energy for rechargeable power source 418. However, a half-wave rectifier circuit may be used to store energy in rechargeable power source 418 at a slower rate. In some examples, recharge circuitry 438 may include both a full-wave rectifier circuit and a half-wave rectifier circuit such that recharge circuitry 438 may switch between each circuit to control the charging rate of rechargeable power source 418 and temperature of IMD 410.

[0055] Rechargeable power source 418 may include one or more capacitors, batteries, and / or other energy storage devices. Rechargeable power source 418 may deliver operating power to the components of IMD 410. In some examples, rechargeable power source 418 may include a power generation circuit to produce the operating power. Rechargeable power source 418 may be configured to operate through many discharge and recharge cycles. Rechargeable power source 418 may also be configured to provide operational power to IMD 410 during the recharge process. In some examples, rechargeable power source 418 may be constructed with materials to reduce the amount of heat generated during charging. In other examples, IMD 410 may be constructed of materials and / or using structures that may help dissipate generated heat at rechargeable power source 418, recharge circuitry 438, and / or secondary coil 416 over a larger surface area of the housing of IMD 410.

[0056] Although rechargeable power source 418, recharge circuitry 438, and secondary coil 416 are shown as contained within the housing of IMD 410, in some implementations, at least one of these components may be disposed outside of the housing. For example, in some implementations, secondary coil 416 may be disposed outside of the housing of IMD 410 to facilitate better coupling between secondary coil 416 and the primary coil of external charging device. In other examples, power source 418 may be a primary power cell and IMD 410 may not include recharge circuitry 438 and recharge coil 416.

[0057] Processing circuitry 430 may also control the exchange of information with an recharger using communication circuitry 436. Processing circuitry 430 may transmit operational information and receive therapy programs or therapy parameter adjustments over an established secure communication channel via communication circuitry 436. Also, in some examples, IMD 410 may communicate with other implanted devices, such as stimulators, control devices, or sensors, via communication circuitry 436. Communication circuitry 436 may include one or more antennas 437 configured to communicate with recharger (such as recharger 150), e.g., for power transfer or with the other devices. In addition, communication circuitry 436 may be configured to control the exchange of information related to sensed and / or determined temperature data, for example temperatures sensed by and / or determined from temperatures sensed using temperature sensor 439. In some examples, communication circuitry 436 may communicate using inductive communication, and in other examples, communication circuitry 436 may communicate using RF frequencies separate from the frequencies used for inductive charging.

[0058] In the example of FIG. 2, communication circuitry 436 includes circuitry 440 configured to manage encryption and decryption and may also execute some of the other functions related to establishing communications channels described in in this disclosure. Inother examples, the encryption functions of circuitry 440 may be handled by processing circuitry 430, or by some other circuitry of IMD 410.

[0059] Communication circuitry 436 may be configured to support wireless communication. For example, communication circuitry 436 may be configured to support wireless communication using Bluetooth™ (e.g., BLE and other versions of Bluetooth™, including future versions of Bluetooth™), Wi-Fi™, Near-Field Communication (NFC), Near Field Magnetic Induction (NFMI), Long Term Evolution, 5th generation (LTE / 5G), or MedRadio (MICS: Medical Implant Communication Service, MEDS: Medical External Device Service, MB AD: Medical Body Area Network)) between IMD 410 and another computing device, e.g., recharger 150 of system 100. In some examples, communication circuitry 436 supports a communication frequency that may correspond to a high frequency or radio frequency, which may be a radio frequency established via Bluetooth, Wi-Fi, Near-Field Communication (NFC), 175KHz inductive communication, or MICS, for example. Communication circuitry 436 may be configured to receive an inductive sting. Processing circuitry 430 of IMD 410 may receive, as updates to programs (e.g., at least one program parameter), values for various stimulation parameters such as magnitude and electrode combination, from recharger via communication circuitry 436. In addition, communication circuitry 436 may communicate with an external medical device via proximal inductive interaction of IMD 410, e.g., during recharging. Communication circuitry 436 may send and receive information on a continuous basis, at periodic intervals, or upon request from the recharger. In some examples, communication circuitry 436 may also be referred to as telemetry circuitry in this disclosure.

[0060] In some examples, communication circuitry 436 may be configured to receive communications or data via secondary coil 416. This data may be received using the same configuration of secondary coil (e.g., tuned to the same frequency) or include tuning circuitry that can adjust the resonant frequency of secondary coil to receive and / or transmit information to another device, such as to a recharger using inductive coupling. In other examples, communication circuitry 436 may be coupled to a different coil than secondary coil 416 for receiving and / or transmitting information.

[0061] In some examples, processing circuitry 430 may transmit additional information to external charging device related to the operation of rechargeable power source 418, e.g., at a more limited authentication level than for sending and receiving operational programming instructions or parameters. For example, processing circuitry 430 may use communication circuitry 436 to transmit indications that rechargeable power source 418 is completely charged, rechargeable power source 418 is fully discharged, the amount of charging current output by recharge circuitry 438 e.g., to power source 418, or any other charge status of rechargeablepower source 418. In some examples, processing circuitry 430 may use communication circuitry 436 to transmit instructions to the external charging device, including instructions regarding control of the charging session, for example instructions to lower the power level or to terminate the charging session, based on the determined temperature of the housing / extemal surface 419 of the IMD.

[0062] Processing circuitry 430 may also transmit information to external charging device that indicates any errors with rechargeable power source 418 that may reduce or limit rechargeable power source 418 from providing operational power to the components of IMD 410. In various examples, processing circuitry 430 may receive, through communication circuitry 436, instructions for algorithms, including formulas and / or values for constants to be used in the formulas that may be used to determine the temperature of the housing 419 and / or exterior surface(s) of housing 419 of IMD 410 based on temperatures sensed by temperature sensor 439 located within IMD 410 during and after a recharging session performed on rechargeable power source 418.

[0063] FIGS. 3-14B show example views and components of example IMD 500. IMD 500 may be an example of IMDs 110 and 410. FIG. 3 is a top view of an example IMD 500. IMD 500 includes top housing 508, band housing 506, main housing 502, and bottom housing 504. Together, top housing 508, band housing 506, main housing 502, and bottom housing 504 may form a complete housing that encloses inner components of IMD 500. In some examples, one or more external portions of IMD 500 may carry an electrode or act as an electrode. For example, some or all of main housing 502 may be used as an electrode that can be used in an electrode combination with another electrode, such as electrode 510 on the opposing side of IMD 500 as shown in FIG. 4. As described herein, the complete housing of IMD 500 may be configured to be implanted in a leg of a patient. IMD 500 may include stimulation generation circuitry within the complete housing that is configured to generate tibial stimulation therapy deliverable via one or more electrodes (e.g., electrode 510 of FIG. 4). The complete housing may be configured to at least partially house electrode 510, electrical connection device 530, feedthrough pin 516, and the stimulation generation circuitry.

[0064] FIG. 4 is a perspective view of example IMD 500. IMD 500 includes top housing 508, which at least partially surrounds electrode 510, electrode surface 512, electrode cavity 518, feedthrough pin 516, and electrode connecting portion 514. Electrode 510 may define electrode surface 512 which is configured to interface with tissue of a patient, electrode connecting portion 514 that is configured to accept an electrical connection device (e.g., an insert), and electrode cavity 518 disposed within a central region of electrode 510. Feedthrough pin 516 is inserted through a channel of electrode connecting portion 514. Electrode 510 is shown as a crescentshape, but the shape may be any shape selected to deliver electrical energy to target tissue. Although electrode connecting portion 514, feedthrough pin 516, and electrode cavity 518 are exposed for illustration in FIG. 4, an insulation material may cover these portions in IMD 500 for implantation into a patient.

[0065] IMD 500 may be an example system that includes electrode 510, electrical connection device 530 (e.g., an insert), and feedthrough pin 516. Electrode 510 may define an inner wall that defines an opening configured to accept electrical connection device 530. Electrical connection device 530 may include an inner cylindrical wall defining an inner channel, where electrical connection device 530 is configured to be pressed into the opening of electrode 510. At least a portion of electrical connection device 530 may be configured to contact a portion of the inner wall of the electrode. In addition, feedthrough pin 516 can be configured to be at least partially inserted into the inner channel of electrical connection device 530.

[0066] FIGS. 5 and 6 are perspective views of example IMD 500 with electrode 510, insert 530, and feedthrough pin 516 exposed. As shown in the example of FIGS. 5 and 6, electrode connecting portion 514 of electrode 510 accepts electrical connection device 530, and feedthrough pin 516 is disposed within electrical connection device 530. Distal portion 516B of feedthrough pin 516 extends out the distal end of electrical connection device 530, and proximal portion 516B of feedthrough pin 516 is also shown extending proximal of electrical connection device 530. Since electrode connecting portion 514 is electrically connected to feedthrough pin 516 via electrode connection device 530, feedthrough pin 516 is electrically connected to electrode surface 512 Insulation 522 is electrically insulative and surrounds electrode 510. Although removed to show electrode connection device 530 in the example of FIGS. 5 and 6, an electrically insulative material may enclose electrode connecting portion 514, electrical connection device 530, and feedthrough pin 516. In some examples, this insulation may create a relatively flat surface for IMD 500.

[0067] Feedthrough pin 516 may be welded to electrical connection device 530. The location of the weld may be on distal portion 516B or any other portion that can be accessible during manufacture. In other examples, electrical connection device 530 may be soldered to feedthrough pin 516 or crimped to feedthrough pin 516. In some examples, electrode 510 is constructed of a Platinum-Iridium material, electrical connection device 530 is constructed of a Titanium metal or Titanium metal alloy, and feedthrough pin 516 is constructed of a Niobium metal or Niobium metal alloy. Other materials may be used in other examples.

[0068] FIG. 7 is a cross-sectional view of example IMD 500 with electrode 510, insert 530, and feedthrough pin 516 having distal portion 516B and proximal portion 516B. As shown in the example of FIG. 7, electrode connecting portion 514 may be coaxial with electrical connectiondevice 530, and electrical connection device 530 may be coaxial with feedthrough pin 516. Proximal portion 516B may extend within the housing of IMD 500 and provide an electrical connection to other circuitry within IMD 500, such as therapy and sensing circuitry 434 (e.g., to sense signals and / or deliver electrical stimulation). Electrode 510 is shown as having a hollow cavity that can be filled with a gas or solid material (e.g., electrical insulation), but electrode 510 may be solid in other examples. Distal portion 516B does not make direct contact with any portion of electrode 510. Feedthrough pin 516 is shown with other feedthrough pins in the examples of FIGS. 7 and 9. These feedthrough pins may or may not be connected to other electrodes or structures. In other examples, feedthrough pin 516 may be the only feedthrough pin of IMD 500 or there may be fewer other feedthrough pins as needed to connect to respective electrodes.

[0069] FIGS. 8 and 9 are cross-sectional side views of example IMD 500 with electrode 510, electrical connection device 530 partially within electrode connecting portion 514, and feedthrough pin 516 partially within electrical connection device 530 and electrode connecting portion 514. As can be seen in the cross-sectional views of FIGS. 8 and 9, electrode connection portion 514 extends from a middle portion of electrode 510 similar to a post. However, electrode connection portion 514 may be formed in any shape that is also configured to define a channel through which electrical connection device 530 and feedthrough pin 516 can be inserted. Insulation 522 surrounds electrode 510 and may electrically insulate electrode 510 from other components or portions of IMD 500.

[0070] FIG. 10 is a perspective view of a front of an example electrode 510. Electrode 510 includes outside portion 534 and electrode surface 512 that is configured to be exposed to the patient. Electrode 510 also includes electrode connecting portion 514 that extends from electrode wall 540 and defines an inner wall that defines opening 542. Opening 542 may be configured to accept electrical connection device 530, through which feedthrough pin 516 can be inserted. Although opening 542 is shown as disposed completely through electrode connecting portion 514, opening 542 may be closed on one end such that electrical connection device 530 only extends out of one end of opening 542.

[0071] FIG. 11 is a perspective view of a back of example electrode 510. Electrode 510 includes outside portion 534 and back curved wall 544 that, together with wall 546, at least partially defines back cavity of electrode 510. Rear wall 548 extends to electrode connecting portion 514 which defines an inner wall that defines opening 542. In other examples, electrode 510 may have other shapes, include different sized cavities or no cavities at all (e.g., solid portions).

[0072] FIG. 12 is a perspective view of a bottom of electrode 510, feedthrough pin 516, and electrical connection device 530 within electrode connecting portion 514. Electrode surface 512 is configured to contact patient tissue. Electrical connection device 530 and / or feedthrough pin 516 may be inserted into electrode connecting portion 514 before or after electrode 510 is installed within the housing of IMD 500.

[0073] FIG. 13 is a side view of example electrical connection device 530, which may be referred to as an insert in some examples. Electrical connection device 530 defines distal face 602 and proximal face 604 which are perpendicular to the longitudinal axis 624 of electrical connection device 530. A proximal portion of electrical connection device 530 includes proximal outer surfaces 614A and 614B (collectively “proximal outer surfaces 614”). A distal portion of electrical connection device 530 includes distal outer surfaces 608A and 608B (collectively “proximal outer surfaces 608”). Electrical connection device 530 may include four sets of distal outer surfaces 608 and proximal outer surfaces 614 at respective circumferential positions around electrical connection device 530. Each of distal outer surfaces 608 and proximal outer surfaces 614 may be separated by a respective shoulder 612 (including shoulders 612A and 612B). Electrical connection device 530 also includes continuous flat outer surfaces 610 at different circumferential positions around the perimeter. Flat outer surface 610 may separate adjacent distal outer surfaces 608 and proximal outer surfaces 614, and flat outer surfaces 610 may have smaller radial dimensions than distal outer surfaces 608 and / or proximal outer surfaces 614 in order to reduce the surface area of electrical connection device 530 that contacts the inner wall of the electrode connection portion to reduce friction during insertion and reduce deformation of the inner channel of electrical connection device 530.

[0074] Shoulders 612 reduce the outer dimension, or radius of the outer surfaces from the proximal to distal portion of electrical connection device 530. The radial dimension difference created by shoulders 612 may be referred to as the distance A. In some examples, the distance A may be less than 0.1 mm (or about 4 one-thousandths of an inch). In some examples, the distance A of should 612 may be about 0.05 mm (or about 2 one-thousandths of an inch). Tapered shoulders 612 have a height (distance A) in a radial direction and a length in the longitudinal direction of longitudinal axis 624 and parallel with the inner channel. The length may be greater than the height for shoulders 612 in some examples. In some examples, the length to height ratio for should 612 may have a ratio greater than 2: 1, 4: 1, or 10: 1. In other examples, the length may be less than or equal to the height for shoulders 612. Although shoulders 612 are shown to have a linear slope, non-linear continuous slopes, stepped slopes, or other shapes may be used in other examples. Shoulders 612 are shown as generally in the middleof the length “L” of electrical connection device 530, but shoulders 612 may be disposed closer to the proximal end or closer to the distal end in other examples.

[0075] Electrical connection device 530 may have an axial length “L” and diameter or diameter “D,” wherein the diameter can be different between the proximal portion and the distal portion. In some examples, electrical connection device 530 may have a length from 0.042 inches to 0.097 inches, or from 0.047 inches to 0.067 inches, and a diameter from 0.018 inches to 0.041 inches. In one example, the length of electrical connection device 530 may have a length of approximately 0.057 inches and a diameter of approximately 0.0306 inches at a proximal portion and 0.0285 inches at a distal portion. The tolerance in the diameter may be approximately 0.0003 inches in some examples. The inner channel can have a diameter of approximately 0.017 inches. The diameter of the outer surface of electrical connection device 530 can be greater or smaller than the example provided as appropriate to connect to the electrode, and the diameter of the channel can be greater or smaller as appropriate to accept feedthrough pin 516. Although the dimension referred to as diameter D may be a diameter in some examples, this dimension may not infer that electrical connection device 530 is circular. Instead, the same dimensions may be referred to as a width or other term. The distal end of electrical connection device 530 includes a tapered shoulder 606 defining a distally decreasing cross-sectional area of the distal portion.

[0076] As described herein, electrical connection device 530 may include a distal portion defining a distal outer surface 608 defining a first cross-sectional dimension and a proximal portion defining a proximal outer surface 614 defining a second cross-sectional dimension larger than the first cross-sectional dimension. Electrical connection device 530 may also include an inner cylindrical wall 704 (FIGS. 14A and 14B) that runs through at least a portion of the distal portion and a portion of the proximal portion, wherein the inner cylindrical wall 704 defines an inner channel 706 that is configured to accept a feedthrough pin therethrough. A shoulder 612 can connect proximal outer surface 614 to distal outer surface 608. In some examples, proximal outer surface 614B, shoulder 612B, and distal outer surface 608B define an outer surface profile at one circumferential position of electrical connection device 530.

[0077] In some examples, the outer surface profile is disposed at four different circumferential positions around a circumference of electrical connection device 530. In addition, the proximal portion and the distal portion of electrical connection device 530 can define a continuous flat outer surface 610 at four different circumferential positions around the circumference of the electrical connection device that are interleaved with the four different circumferential positions of the outer surface profile. Although the example of electrical connection device 530 has four flat outer surfaces 610 and four outer surface profiles, fewer orgreater such circumferential segments may be provided in other examples. For example, only three flat outer surfaces 610 and three outer surface profiles may be used, or five, six, eight, or more flat outer surfaces 610 and five, six, eight, or more outer surface profiles may be used. In some examples, flat outer surfaces 610 can reduce the interference between parts, such as a channel within which electrical connection device 530 can be pressed. In some examples, flat outer surfaces 610 can be created with dimensions that reduce interference compared with a cylindrical object of the same diameter in a range from 55 percent to 85 percent. In other words, flat outer surfaces 610 can reduce the material at the circumference of a cylinder of the same diameter in a range from 55 percent to 85 percent. In one example, flat outer surfaces 610 can reduce the interference area by about 70 percent compared with a cylindrical object of the same diameter. In some examples, the outer surface profile of electrical connection device 530 may be created from a round cylinder. Portions of electrical connection device 530 may be shaved or ground off to create flat outer surfaces 610, shoulders 612, etc. In other examples, electrical connection device 530 may be cut from a rectangular solid piece of material, or formed via casting.

[0078] The distal end of the distal portion of electrode connection device 530 may include a tapered shoulder 606 defining a distally decreasing cross-sectional area of the distal portion. In this manner, tapered shoulder 606 may have a generally conical shape in some examples. A proximal end of the proximal portion of electrode connection device 530 may define an inner chamfer 712 (FIG. 14B) from a proximal end surface to a proximal end of the inner cylindrical wall 704. In some examples, electrical connection device 530 is constructed of a metal or metal alloy comprising titanium, but other electrically conductive materials may be used in other examples.

[0079] FIGS. 14A and 14B are perspective views of example electrical connection device 530. As shown in FIG. 14 A, distal face 602 may define the distal opening of inner channel 706 defined by inner cylindrical wall 704. As shown in FIG. 14B, proximal face 604 may define the proximal opening of inner channel 706 defined by inner cylindrical wall 704. In addition, electrical connection device 530 may define inner chamfer 712 that runs from proximal end surface of proximal face 604 to a proximal end of the inner cylindrical wall 704. Inner chamfer 712 may have a conical shape in some examples. Inner chamfer 712 may facilitate the insertion of the feedthrough pin into inner channel 706.

[0080] FIG. 15 is an example technique for assembling a feedthrough pin with an insert and electrode. Feedthrough pin 516, electrode 510, and electrical connection device 530 are used as examples in the technique of FIG. 15, but other examples of those components may be used in other examples. As shown in the example of FIG. 15, a user or machine may press electricalconnection device 530 into opening 542 of electrode 510 (e.g., into electrode connecting portion 514 of electrode 510) (900). The user or machine may then insert the distal end of feedthrough pin 516 through inner channel 706 of electrical connection device 530 (902). Next, the user or machine may weld (e.g., laser weld or other type of welding) feedthrough pin 516 to electrical connection device 530 (904). The weld may be placed at the distal end of electrical connection device 530 which may be exposed from electrode connecting portion 514 of electrode 510. In other examples, the weld may be performed at other locations. In some examples, electrical connection device 530 may be crimped to feedthrough pin 516 instead of, or in addition to, welding.

[0081] The following examples are described herein.

[0082] Example 1. A system comprising: an electrode defining an inner wall that defines an opening configured to accept an electrical connection device; an electrical connection device comprising an inner cylindrical wall defining an inner channel, wherein the electrical connection device is configured to be pressed into the opening, wherein at least a portion of the electrical connection device is configured to contact a portion of the inner wall of the electrode; and a feedthrough pin configured to be at least partially inserted into the inner channel of the electrical connection device.

[0083] Example 2. The system of example 1, wherein the feedthrough pin is welded to the electrical connection device.

[0084] Example 3. The system of any of examples 1 and 2, wherein: the electrode is constructed of a Platinum-Iridium material; the electrical connection device is constructed of a Titanium metal or Titanium metal alloy; and the feedthrough pin is constructed of a Niobium metal or Niobium metal alloy.

[0085] Example 4. The system of any of examples 1 through 3, wherein the electrical connection device comprises: a distal portion defining a distal outer surface defining a first cross- sectional dimension; and a proximal portion defining a proximal outer surface defining a second cross-sectional dimension larger than the first cross-sectional dimension, wherein the inner cylindrical wall runs through at least a portion of the distal portion and a portion of the proximal portion, wherein the inner cylindrical wall defines an inner channel that is configured to accept a feedthrough pin therethrough.

[0086] Example 5. The system of example 4, further comprising a shoulder that connects the proximal outer surface to the distal outer surface.

[0087] Example 6. The system of any of examples 4 and 5, wherein: the proximal outer surface, the shoulder, and the distal outer surface define an outer surface profile at one circumferential position of the electrical connection device; the outer surface profile is disposedat four different circumferential positions around a circumference of the electrical connection device; and the proximal portion and the distal portion define a continuous flat outer surface at four different circumferential positions around the circumference of the electrical connection device that are interleaved with the four different circumferential positions of the outer surface profile.

[0088] Example 7. The system of any of examples 4 through 6, wherein a radial dimension difference between a first radius of the proximal outer surface and a second radius of the distal outer surface is less than 0.1 mm.

[0089] Example 8. The system of any of examples 4 through 7, wherein: a distal end of the distal portion comprises a tapered shoulder defining a distally decreasing cross-sectional area of the distal portion; and a proximal end of the proximal portion comprises an inner chamfer from a proximal end surface to a proximal end of the inner cylindrical wall.

[0090] Example 9. The system of any of examples 1 through 8, further comprising an implantable medical device comprising the electrode, the electrical connection device, and the feedthrough pin.

[0091] Example 10. The system of example 9, further comprising a housing configured to be implanted in a leg of a patient and stimulation generation circuitry configured to generate tibial stimulation therapy deliverable via the electrode, wherein the housing configured to at least partially house the electrode, the electrical connection device, the feedthrough pin, and the stimulation generation circuitry.

[0092] Example 11. An electrical connection device, the device comprising: a distal portion defining a distal outer surface defining a first cross-sectional dimension; a proximal portion defining a proximal outer surface defining a second cross-sectional dimension larger than the first cross-sectional dimension; and an inner cylindrical wall that runs through at least a portion of the distal portion and a portion of the proximal portion, wherein the inner cylindrical wall defines an inner channel that is configured to accept a feedthrough pin therethrough.

[0093] Example 12. The electrical connection device of example 11, further comprising a shoulder that connects the proximal outer surface to the distal outer surface.

[0094] Example 13. The electrical connection device of any of examples 11 and 12, wherein the proximal outer surface, the shoulder, and the distal outer surface define an outer surface profile at one circumferential position of the electrical connection device.

[0095] Example 14. The electrical connection device of example 13, wherein the outer surface profile is disposed at four different circumferential positions around a circumference of the electrical connection device.

[0096] Example 15. The electrical connection device of example 14, wherein the proximal portion and the distal portion define a continuous flat outer surface at four different circumferential positions around the circumference of the electrical connection device that are interleaved with the four different circumferential positions of the outer surface profile.

[0097] Example 16. The electrical connection device of any of examples 11 through 15, wherein a radial dimension difference between a first radius of the proximal outer surface and a second radius of the distal outer surface is less than 0.1 mm.

[0098] Example 17. The electrical connection device of any of examples 11 through 16, wherein a distal end of the distal portion comprises a tapered shoulder defining a distally decreasing cross-sectional area of the distal portion.

[0099] Example 18. The electrical connection device of example 17, wherein the tapered shoulder has a height in a radial direction and a length in a longitudinal direction parallel with the inner channel, wherein the length is greater than the height.

[0100] Example 19. The electrical connection device of any of examples 11 through 18, wherein a proximal end of the proximal portion comprises an inner chamfer from a proximal end surface to a proximal end of the inner cylindrical wall.

[0101] Example 20. The electrical connection device of any of examples 11 through 19, wherein the electrical connection device is constructed of a metal or metal alloy comprising titanium.

[0102] In one or more examples, the functions described above may be implemented in hardware, software, firmware, or any combination thereof. For example, the various components of FIGS. 1 and 2, processing circuitry 430 may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over, as one or more instructions or code, a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another, e.g., according to a communication protocol. In this manner, computer- readable media generally may correspond to (1) tangible computer-readable storage media which is non-transitory or (2) a communication medium such as a signal or carrier wave. Data storage media may be any available media that may be accessed by one or more computers or one or more processors to retrieve instructions, code and / or data structures for implementation of the techniques described in this disclosure. A computer program product may include a computer- readable medium.

[0103] The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, a non-transitory storage medium may store data that may, over time, change (e.g., in RAM or cache). By way of example, and not limitation, such computer-readable storage media, may include random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a compact disc ROM (CD-ROM), a floppy disk, a cassette, magnetic media, optical media, or other computer readable media. In some examples, an article of manufacture may include one or more computer-readable storage media.

[0104] Also, any connection is properly termed a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. It should be understood, however, that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but are instead directed to non-transient, tangible storage media. Combinations of the above should also be included within the scope of computer-readable media.

[0105] Instructions may be executed by one or more processors, such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” and “processing circuitry,” as used herein, may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. Also, the techniques could be fully implemented in one or more circuits or logic elements.

[0106] The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including, an integrated circuit (IC) or a set of ICs (e.g., a chip set). Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, various units may be combined in a hardware unit or provided by a collection of interoperative hardware units, including one or more processors as described above, in conjunction with suitable software and / or firmware.

[0107] Various examples of the disclosure have been described. These and other examples are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A system comprising: an electrode defining an inner wall that defines an opening configured to accept an electrical connection device; an electrical connection device comprising an inner cylindrical wall defining an inner channel, wherein the electrical connection device is configured to be pressed into the opening, wherein at least a portion of the electrical connection device is configured to contact a portion of the inner wall of the electrode; and a feedthrough pin configured to be at least partially inserted into the inner channel of the electrical connection device.

2. The system of claim 1, wherein the feedthrough pin is welded to the electrical connection device.

3. The system of any of claims 1 and 2, wherein: the electrode is constructed of a Platinum-Iridium material; the electrical connection device is constructed of a Titanium metal or Titanium metal alloy; and the feedthrough pin is constructed of a Niobium metal or Niobium metal alloy.

4. The system of any of claims 1 through 3, wherein the electrical connection device comprises: a distal portion defining a distal outer surface defining a first cross-sectional dimension; and a proximal portion defining a proximal outer surface defining a second cross-sectional dimension larger than the first cross-sectional dimension, wherein the inner cylindrical wall runs through at least a portion of the distal portion and a portion of the proximal portion, wherein the inner cylindrical wall defines an inner channel that is configured to accept a feedthrough pin therethrough.

5. The system of claim 4, further comprising a shoulder that connects the proximal outer surface to the distal outer surface.

6. The system of any of claims 4 and 5, wherein the proximal outer surface, the shoulder, and the distal outer surface define an outer surface profile at one circumferential position of the electrical connection device.

7. The system of claim 6, wherein the outer surface profile is disposed at four different circumferential positions around a circumference of the electrical connection device.

8. The system of claim 7, wherein the proximal portion and the distal portion define a continuous flat outer surface at four different circumferential positions around the circumference of the electrical connection device that are interleaved with the four different circumferential positions of the outer surface profile.

9. The system of any of claims 4 through 8, wherein a radial dimension difference between a first radius of the proximal outer surface and a second radius of the distal outer surface is less than 0.1 mm.

10. The system of any of claims 4 through 9, wherein a distal end of the distal portion comprises a tapered shoulder defining a distally decreasing cross-sectional area of the distal portion.

11. The system of claim 10, wherein the tapered shoulder has a height in a radial direction and a length in a longitudinal direction parallel with the inner channel, wherein the length is greater than the height.

12. The system of any of claims 4 through 11, wherein a proximal end of the proximal portion comprises an inner chamfer from a proximal end surface to a proximal end of the inner cylindrical wall.

13. The system of any of claims 1 through 12, wherein the electrical connection device is constructed of a metal or metal alloy comprising titanium.

14. The system of any of claims 1 through 13, further comprising an implantable medical device comprising the electrode, the electrical connection device, and the feedthrough pin.

15. The system of claim 14, further comprising a housing configured to be implanted in a leg of a patient and stimulation generation circuitry configured to generate tibial stimulation therapy deliverable via the electrode, wherein the housing is configured to at least partially house the electrode, the electrical connection device, the feedthrough pin, and the stimulation generation circuitry.

Images