Rechargeable implants and methods for estimating maximum applied temperatures during implant recharge

Abstract

A system according to at least one embodiment of the present disclosure includes: a processor; and a memory storing data thereon that, when processed by the processor, enable the processor to: receive temperature information associated with an implanted device configured to be charged by a recharger; estimate, based on the temperature information, position information associated with at least one of the recharger and the implanted device; estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted device; and control, based on the estimated temperature, at least one operating parameter of the recharger.

Description

RECHARGEABLE IMPLANTS AND METHODS FOR ESTIMATING MAXIMUMAPPLIED TEMPERATURES DURING IMPLANT RECHARGECROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of and priority to U.S. Provisional Application No. 63 / 636,005 filed on April 18, 2024, entitled “RECHARGEABLE IMPLANTS AND METHODS FOR ESTIMATING MAXIMUM APPLIED TEMPERATURES DURING IMPLANT RECHARGE”, the entirety of which is hereby incorporated herein by reference.BACKGROUND

[0002] The present disclosure is generally directed to medical devices, and relates more particularly to rechargeable implantable medical devices.

[0003] Medical devices may be external or implanted, and may be used to deliver electrical stimulation therapy to various tissue sites of a patient to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson’s disease, other movement disorders, epilepsy, urinary or fecal incontinence, sexual dysfunction, obesity, or gastroparesis. A medical device delivers electrical stimulation therapy via one or more leads that include electrodes located proximate to target locations associated with the brain, the spinal cord, pelvic nerves, peripheral nerves, or the gastrointestinal tract of a patient. Electrical stimulation is used in different therapeutic applications, such as DBS, spinal cord stimulation (SCS), pelvic stimulation, gastric stimulation, or peripheral nerve field stimulation (PNFS).BRIEF SUMMARY

[0004] Implantable medical devices (IMDs) may be implanted in patients for extended periods of time to provide one or more therapies, such that IMDs often include rechargeable power sources. However, such wireless recharging requires a patient to hold a recharger device over the IMD for prolonged periods of time. Given the positional inaccuracies associated with manually aligning the recharger with the IMD, excess heat may be generated and passed into adjacent anatomical tissues. While some recharge systems minimize potential patient harm by controlling recharging using the heat limit of the IMD, such methods nonetheless can result in long recharge times for the patient. According to embodiments of the present disclosure, temperature information is used toestimate the recharger position relative to the IMD, and then to estimate the maximum applied temperature to the anatomical tissues. The maximum applied temperature is then controlled for, resulting in improved recharging for non-optimal wireless couplings and decreased overall recharge times for the patient.

[0005] Example aspects of the present disclosure include:

[0006] A system according to at least one embodiment of the present disclosure comprises: a processor; and a memory storing data thereon that, when processed by the processor, enable the processor to: receive temperature information associated with an implanted device configured to be charged by a recharger; estimate, based on the temperature information, position information associated with at least one of the recharger and the implanted device; estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted device; and control, based on the estimated temperature, at least one operating parameter of the recharger.

[0007] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: decrease a power output of the recharger when the temperature applied to the anatomical element meets or exceeds a threshold value.

[0008] Any of the aspects herein, wherein estimating the position information associated with at least one of the recharger and the implanted device comprises using an objective function trained with a gradient descent operator to estimate the temperature information.

[0009] Any of the aspects herein, wherein the temperature information is received from at least four temperature sensors.

[0010] Any of the aspects herein, wherein the at least four temperature sensors are positioned in a cross pattern in the implanted device.

[0011] Any of the aspects herein, wherein a first sensor and a second sensor of the at least four temperature sensors are positioned within a first area of a housing of the implanted device, and wherein a third sensor and a fourth sensor of the at least four temperature sensors are positioned within a second area of the housing different from the first area.

[0012] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: render, to a user interface, information associated with at least one of the temperature information, the estimated temperature, and the at least one operating parameter of the recharger.

[0013] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: disable operation of the recharger when at least one of anenergy storage device of the implanted device is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

[0014] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: estimate a heat associated with the implanted device; and control, based on the estimated heat, the at least one operating parameter of the recharger.

[0015] Any of the aspects herein, wherein the position information comprises a position of the recharger relative to the implanted device.

[0016] Any of the aspects herein, wherein the position information comprises a location on the implanted device.

[0017] Any of the aspects herein, wherein the location comprises a point in two- dimensional (2D) or three-dimensional (3D) space.

[0018] A system according to at least one embodiment of the present disclosure comprises: a recharger device configured to recharge an implanted medical device; a processor; and a memory storing data thereon that, when processed by the processor, enable the processor to: receive temperature information associated with the implanted medical device; estimate, based on the temperature information, position information associated with at least one of the recharger device and the implanted medical device; estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted medical device; and control, based on the estimated temperature, at least one operating parameter of the recharger device.

[0019] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: decrease a power output of the recharger device when the temperature applied to the anatomical element meets or exceeds a threshold value.

[0020] Any of the aspects herein, wherein estimating the position information associated with at least one of the recharger device and the implanted medical device comprises using an objective function trained with a gradient descent operator to estimate the temperature information.

[0021] Any of the aspects herein, wherein the temperature information is received from at least four temperature sensors.

[0022] Any of the aspects herein, wherein the at least four temperature sensors are positioned in a cross pattern in the implanted medical device.

[0023] Any of the aspects herein, wherein a first sensor and a second sensor of the at least four temperature sensors are positioned within a first area of a housing of the implanted medical device, and wherein a third sensor and a fourth sensor of the at leastfour temperature sensors are positioned within a second area of the housing different from the first area.

[0024] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: render, to a user interface, information associated with at least one of the temperature information, the estimated temperature, and the at least one operating parameter of the recharger device.

[0025] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: disable operation of the recharger device when at least one of an energy storage device of the implanted medical device is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

[0026] Any of the aspects herein, wherein the data, when processed by the processor, further enable the processor to: estimate a heat associated with the implanted medical device; and control, based on the estimated heat, the at least one operating parameter of the recharger device.

[0027] Any of the aspects herein, wherein the position information comprises a position of the recharger device relative to the implanted medical device.

[0028] Any of the aspects herein, wherein the position information comprises a location on the implanted medical device.

[0029] Any of the aspects herein, wherein the location comprises a point in two- dimensional (2D) or three-dimensional (3D) space.

[0030] A method according to at least one embodiment of the present disclosure comprises: receiving temperature information associated with an implanted device configured to be charged by a recharger; estimating, based on the temperature information, position information associated with at least one of the recharger and the implanted device; estimating, based on the position information, a temperature applied to an anatomical element proximate the implanted device; and controlling, based on the estimated temperature, at least one operating parameter of the recharger.

[0031] Any of the aspects herein, further comprising: decreasing a power output of the recharger when the temperature applied to the anatomical element meets or exceeds a threshold value.

[0032] Any of the aspects herein, wherein the temperature information is received from at least four temperature sensors positioned in a cross pattern in the implanted device.

[0033] Any of the aspects herein, further comprising: disabling operation of the recharger when at least one of an energy storage device of the implanted device is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

[0034] Any of the aspects herein, further comprising: estimating a heat associated with the implanted device; and controlling, based on the estimated heat, the at least one operating parameter of the recharger.

[0035] Any of the aspects herein, wherein the position information comprises a position of the recharger relative to the implanted device.

[0036] Any of the aspects herein, wherein the position information comprises a location on the implanted device.

[0037] Any of the aspects herein, wherein the location comprises a point in two- dimensional (2D) or three-dimensional (3D) space.

[0038] Any aspect in combination with any one or more other aspects.

[0039] Any one or more of the features disclosed herein.

[0040] Any one or more of the features as substantially disclosed herein.

[0041] Any one or more of the features as substantially disclosed herein in combination with any one or more other features as substantially disclosed herein.

[0042] Any one of the aspects / features / embodiments in combination with any one or more other aspects / features / embodiments.

[0043] Use of any one or more of the aspects or features as disclosed herein.

[0044] 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 embodiment.

[0045] 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.

[0046] The phrases “at least one”, “one or more”, 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” and “A, B, and / 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. When each one of A, B, and C in the above expressions refers to an element, such as X, Y, and Z, or class of elements, such as Xl-Xn, Yl-Ym, and Zl-Zo, the phrase is intended torefer to a single element selected from X, Y, and Z, a combination of elements selected from the same class (e.g., XI and X2) as well as a combination of elements selected from two or more classes (e.g., Y1 and Zo).

[0047] 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.

[0048] 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, embodiments, 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, embodiments, 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.

[0049] Numerous additional features and advantages of the present disclosure will become apparent to those skilled in the art upon consideration of the embodiment descriptions provided hereinbelow.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0050] 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, embodiments, and configurations of the disclosure, as illustrated by the drawings referenced below.

[0051] Fig. l is a conceptual diagram of a system according to at least one embodiment of the present disclosure;

[0052] Fig. 2A is a block diagram of an IMD according to at least one embodiment of the present disclosure;

[0053] Fig. 2B is a conceptual diagram of the IMD according to at least one embodiment of the present disclosure;

[0054] Fig. 2C is a chart depicting input measurements and an estimated maximum temperature output from a data model according to at least one embodiment of the present disclosure;

[0055] Fig. 3 is a block diagram of an external charging device according to at least one embodiment of the present disclosure;

[0056] Fig. 4 depicts example temperature information and electrical measurements according to at least one embodiment of the present disclosure;

[0057] Fig. 5A depicts battery current and applied temperature when a recharger is in a mediocre position according to at least one embodiment of the present disclosure;

[0058] Fig. 5B depicts battery current and applied temperature when the recharger is in a poor position according to at least one embodiment of the present disclosure;

[0059] Fig. 6 is a flowchart according to at least one embodiment of the present disclosure;

[0060] Fig. 7 is a flowchart according to at least one embodiment of the present disclosure; and

[0061] Fig. 8 is a flowchart according to at least one embodiment of the present disclosure.DETAILED DESCRIPTION

[0062] 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 embodiment, 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 embodiments 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.

[0063] In one or more examples, the described methods, processes, and techniques may be implemented in hardware, software, firmware, or any combination thereof. Ifimplemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Alternatively or additionally, functions may be implemented using machine learning models, neural networks, artificial neural networks, or combinations thereof (alone or in combination with instructions). Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

[0064] Before any embodiments 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 embodiments 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.

[0065] Neuromodulation systems used for neuromodulation may deliver one or more therapies to a patient. For example, spinal cord stimulation (SCS) brings relief from chronic pain to thousands of patients every day, often as an alternative to opioids or other analgesics. Because SCS is non-life-sustaining and uses a lot of power, the vast majority of implants are rechargeable. Most patients holds a recharger to their lower back (or other area in which the implanted device has been implanted) for extended periods of time, such as for 30 to 60 minutes per day. The recharger generates a magnetic field that induces a current in the implanted device sufficient to recharge the batteries of the implantable device. Such inductive charging also generates heat on a shield of the implanted device.

[0066] In some cases, the placement of the recharger relative to the implanted device may vary, resulting in various heat distributions on the shield. Moreover, when the patient moves the recharger relative to the implant, the location of the maximum shieldtemperature (a “hot spot”) may move. In order to ensure patient safety, the maximum temperature on the shield surface should be limited regardless of the location of the recharger relative to the implanted device. However, direct measurement of the shield temperature may be difficult, since temperature measurements may be limited to internal components.

[0067] According to at least one embodiment of the present disclosure, the recharger’s position is estimated using thermal gradients and electrical measurements, and the position is used in conjunction with on-hybrid measurements to predict the maximum shield temperature. Once the hottest spot on the implant’s surface has been estimated, the applied temperature can be used as a control input to limit recharger power output.

[0068] Embodiments of the present disclosure provide technical solutions to one or more of the problems of (1) inaccurate measurements or estimations of patient tissue temperature during implant recharging, and (2) inefficient or long recharge times.

[0069] Turning first to Fig. 1, a conceptual diagram of a system 100 according to at least one example embodiment of the present disclosure is shown. The system 100 may be used to provide electrical stimulation to a patient, to recharge an IMD, and / or to carry out one or more other aspects of any of the methods disclosed herein. For example, the system 100 may include an IMD 112 that may be configured to generate a current or electrical signal, such as a signal capable of stimulating a target anatomical element. The system 100 also includes an external charging device 120 that can be used to charge, program, command, and / or otherwise control the IMD 112. The IMD 112 may be configured to be implanted into the patient 102 for weeks, months, years, or the like. In other cases, the IMD 112 may be or comprise a temporarily implanted or trial stimulation used to screen or evaluate the efficacy of electrical stimulation for treating chronic conditions.

[0070] In some cases, the IMD 112 may generate a current or electrical signal capable of stimulating an ECAP response from one or more nerves or an LFP. In other examples, the IMD 112 may generate stimulations proximate the sacral nerve, within the brain, and / or proximate the peripheral nerves in order to perform SCS, sacral neuromodulation (SNM), DBS, peripheral nerve stimulation (PNS), combinations thereof, and / or the like. The IMD 112 depicted in Fig. 1 comprises a first lead 116A and a second lead 116B implanted near or on a spinal cord 104 of a patient 102. In some cases, the IMD 112 may have an additional or alternative number of leads 116. The leads 116A, 116B may be implanted on or near any target anatomical element (e.g., on or near any organ, anatomical tissue, anatomical element, nerve, combinations thereof, etc.). In some cases, the leads 116A,116B may be implanted in the epidural space between the spinal cord and the vertebrae. Once implanted, the leads 116A, 116B may provide electrical signals from the IMD 112 to the target anatomical element. The IMD 112 may be implantable in a patient or may be external to the patient, such as during testing of the leads 116A, 116B. It is to be understood that the systems and methods discussed herein, although described as an application to an implantable neurostimulation, are provided for the purposes of illustration only, and that the systems and methods described herein are generally applicable to a variety of medical devices including medical devices such as patient monitors, electrical stimulations, drug delivery devices, and the like.

[0071] In some examples, the leads 116A, 116B may provide the electrical signals to respective nerves via electrodes that are connected to the nerves (e.g., sutured in place, wrapped around the nerves, etc.). In some examples, the leads 116A, 116B may be referenced as cuff electrodes or may otherwise include the cuff electrodes (e.g., at an end of the leads 116A, 116B not connected or plugged into the IMD 112). Additionally or alternatively, while shown as physical wires that provide the connection between the IMD 112 and the one or more nerves, the electrodes may provide the electrical signals to the one or more nerves wirelessly (e.g., with or without the IMD 112).

[0072] The electrodes may comprise stimulating electrodes (e.g., electrodes configured to stimulate a target anatomical element) and / or recording electrodes (e.g., electrodes configured to record a physiological response to the stimulation). In some cases, both the first lead 116A and the second lead 116B comprise both stimulating electrodes and recording electrodes. In other cases, the first lead 116A comprises stimulating electrodes while the second lead 116B comprises recording electrodes (or vice versa). In some examples, the recording electrode may record or measure the Evoked Compound Action Potentials (ECAPs) or other signals evoked from the target anatomical element based on stimulations delivered by the stimulating electrode.

[0073] The IMD 112 may include a secondary coil 118. In other cases, the secondary coil 118 may be positioned or located external to the IMD 112. In such cases, the secondary coil 118 may be electrical coupled to the IMD 112 to enable the IMD 112 to be recharged. The configuration of the IMD 112 and the secondary coil 118 may vary from patient to patient and may depend, for example, on the patient’s symptoms and / or characteristics, the type of therapy to be delivered, the implant location of the leads 116A, 116B, combinations thereof, and the like. In some cases, the positioning of the secondary coil 118 relative to the IMD 112 may be chosen to improve inductive coupling betweenthe secondary coil 118 and the external charging device 120 and / or to minimize the likelihood of disrupting nearby anatomical tissues.

[0074] An electrical current may be induced within the secondary coil 118 to charge the battery or other power source(s) of the IMD 112 when a coil 128 in the external charging device 120 produces a magnetic field that is aligned with the secondary coil 118. The induced electrical current may first be conditioned and converted by a charging module (e.g., a charging circuit) to an electrical signal that can be applied to the battery or other power source(s) with an appropriate charging current. For instance, the inductive current may be an alternating current (AC) that is converted to a direct current (DC) capable of charging the battery or other power source(s). The power source(s) of the IMD 112 may be or comprise one or more chemical or electrical energy storage devices (e.g., batteries, capacitors, etc.) capable of being refilled or recharged by the induction of current in the secondary coil 118. For instance, AC from the secondary coil 118 may be conditioned or converted by a charging circuit into DC, and then sent to the power source(s) for storage. As a result, the IMD 112 can be recharged when the energy available for use is wholly or partially depleted. In some cases, the secondary coil 118 may comprise a plurality of separate coils displaced from one another along one or more spatial dimensions (e.g., to improve inductive coupling between the secondary coil 118 and the coil 128).

[0075] The external charging device 120 comprises a patient interface device 124 connected to the coil 128 via a wired connection or wireless connection (e.g., wirelessly linked using a device pairing technology). The patient interface device 124 may provide storage for one or more electrical components of the external charging device 120 (e.g., processors, memory, user interface, telemetry circuitry, power source, etc.). In some cases, the secondary coil 118 may be positioned on an exterior surface of external charging device 120 or within the external charging device 120. In some cases, the patient interface device 124 and the coil may be wirelessly connected, and any wired connections (e.g., a cable connection) may be omitted. The external charging device 120 may be used to recharge the IMD 112 while the IMD 112 remains implanted in the patient 102. The external charging device 120 may be or comprise, for example, a hand-held device, a portable device, a stationary charging system, and / or the like. The external charging device 120 comprises components sufficient to enable the external charging device 120 to charge the IMD 112 through the tissue of the patient 102. In some cases, the external charging device 120 may be controlled by another device (e.g., an external programmer controllable by a patient, a physician, or the like).

[0076] The coil 128 may be or comprise a wound conductive wire in an in-plane spiral (e.g., a disk-shaped coil), in a multi-dimensional spiral (e.g., a helix), or in any other configuration sufficient to perform inductive charging when coupled with the secondary coil 118. In some examples, the coil 128 may be flexible to conform with the skin surface of the patient 102. The coil 128 may be partially or wholly enclosed in a flexible housing that enables or promotes flexibility in the coil 128, such that the coil 128 within the flexible housing can be placed on the skin of the patient 102 to couple with the secondary coil 118.

[0077] The IMD 112 and the external charging device 120 may implement any wireless power transfer techniques capable of recharging the IMD 112 while the IMD 112 is implanted in the patient 102. For example, the secondary coil 118 of the IMD 112 may be inductively coupled with the coil 128 of the external charging device 120 by positioning the coil 128 near the IMD 112 to align the coil 128 with the secondary coil 118. The external charging device 120 may then generate an electrical current in the coil 128. When the secondary coil 118 and the coil 128 are aligned, the electrical current in the coil 128 magnetically induces an electrical current in the secondary coil 118. The induced electrical current may be used to increase the charge level (e.g., voltage) of the rechargeable power source(s) of the IMD 112.

[0078] The external charging device 120 may include a heat sink 132 removably attached to the coil 128 to absorb heat generated by the coil 128 when current flows therethrough. In some embodiments, the heat sink 132 may be similarly flexible to the coil 128, such that when the heat sink 132 is attached to the coil 128, the coil 128 can still bend or conform to the patient 102 when applied to the skin of the patient 102. In cases where the coil 128 is disposed partially or wholly within the external charging device 120, the heat sink 132 may be configured to attach to the external charging device 120 to absorb heat generated by the coil 128. In some embodiments, the external charging device 120 may be configured as described in U.S. Patent No. 11,896,838, which is incorporated herein by reference.

[0079] Turning next to Figs. 2A-2B, aspects of example components of the IMD 112 in accordance with at least one example embodiment of the present disclosure are shown. The illustrated IMD includes stimulation generation circuitry 202, sensing circuitry 204, processing circuitry 210, a memory 212, one or more power source(s) 216, telemetry circuitry 220, temperature sensor(s) 224, and a recharge module 228. Any one or more components of the illustrated IMD may be positioned on a printed circuit board (PCB) 232positioned within the IMD. IMDs according to other examples of the present disclosure may comprise additional or alternative components than those shown in the IMD 112. It is to be understood that, while the stimulation generation circuitry 202, the sensing circuitry 204, the processing circuitry 210, and the telemetry circuitry 220 are described as separate circuitry, in some cases the stimulation generation circuitry 202, the sensing circuitry 204, the processing circuitry 210, and the telemetry circuitry 220 may be functionally integrated.

[0080] The stimulation generation circuitry 202, under the control of the processing circuitry 210, generates stimulation signals (e.g., electrical stimulation signals for evoking Evoked Resonant Neural Activity (ERNA) signals and / or therapeutic electrical stimulation signals for delivering therapy) for delivery to the patient 102 via electrodes 206, 208. While stimulation pulses are described, stimulation signals may be of any form, such as continuous-time signals (e.g., sine waves) or the like. In some cases, the IMD 112 may be leadless (e.g., the IMD 112 omits the leads 116). One example of a leadless IMD 112 may be a Tibial Neuromodulation Implantable Neurostimulator (INS).

[0081] The sensing circuitry 204 is configured to monitor signals from any combination of the electrodes 206, 208. Although the sensing circuitry 204 is incorporated into a common housing with the stimulation generation circuitry 202 and the processing circuitry 210 in Fig. 2A, in other examples, the sensing circuitry 204 may be in a separate housing from the IMD 112 and may communicate with the processing circuitry 210 via wired or wireless communication techniques. The sensing circuitry 204 is configured to monitor signals from any combination of the electrodes 206, 208.

[0082] In some examples, the sensing circuitry 204 includes one or more amplifiers, filters, and analog-to-digital converters. The sensing circuitry 204 may be used to sense physiological signals, such as ERNA signals. In some examples, sensing circuitry 204 measures ERNA signals from a particular combination of the electrodes 206, 208. In some cases, the particular combination of electrodes for sensing includes different electrodes than a set of electrodes 206, 208 used to deliver electrical stimulation signals (e.g., therapeutic electrical stimulation signals or electrical stimulation signals for evoking ERNA signals). Alternatively, in other cases, the particular combination of electrodes used for sensing includes at least one of the same electrodes as a set of electrodes used to deliver stimulation signals to the patient 102. The sensing circuitry 204 may provide signals to an analog-to-digital converter, for conversion into a digital signal for processing, analysis, storage, or output by the processing circuitry 210.

[0083] The processing circuitry 210 may include fixed function processing circuitry and / or programmable processing circuitry, and may comprise, for example, any one or more of a processor, a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functions attributed to the processing circuitry 210 herein may be embodied as firmware, hardware, software or any combination thereof. The processing circuitry 210 may control the stimulation generation circuitry 202 (or any other circuitry) according to therapy programs stored in the memory 212 to apply particular parameter values specified by one or more of programs. In some embodiments, the processing circuitry 210 may perform one or more control functions associated with the recharging of the IMD 112, such as by controlling power output by the IMD 112 to maintain a safe temperature of the IMD 112.

[0084] The memory 212 may include any volatile or non-volatile media, such as a random-access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, any memory discussed herein, and / or any other tangible, non-transitory memory for storing computer-readable data and / or instructions. The memory 212 may store computer- readable instructions that, when executed by the processing circuitry 210, cause the IMD 112 to perform various functions. The memory 212 may be a storage device or other non- transitory medium. The memory 212 may store information or data useful for completing, for example, any step of the methods 600, 700, and / or 800 described herein, or of any other method. The memory 212 may store, for example, instructions and / or machine learning models that support one or more functions of the IMD 112. For instance, the memory 212 may store content (e.g., instructions and / or machine learning models) that, when executed by the processing circuitry 210, enable the IMD 112 to control power output of the external charging device 120 to keep the estimated temperature applied to patient tissue below a maximum temperature threshold. Such content, if provided as in instruction, may, in some embodiments, be organized into one or more applications, modules, packages, layers, or engines.

[0085] Alternatively or additionally, the memory 212 may store other types of content or data (e.g., machine learning models, artificial neural networks, deep neural networks, etc.) that can be processed by the processing circuitry 210 to carry out the various methods and features described herein. Thus, although various contents of memory 212 may be described as instructions, it should be appreciated that functionality described herein canbe achieved through use of instructions, algorithms, and / or machine learning models. The data, algorithms, and / or instructions may cause the processing circuitry 210 to manipulate data stored in the memory 212 and / or received from or via the external charging device 120, a programming device, and / or the like.

[0086] In one example, the memory 212 comprises or stores a data model 236. The data model 236 may be or comprise a neural network (e.g., a convolutional neural network, a deep neural network, a recurrent neural network, combinations thereof, etc.) that is trained to receive one or more inputs such as temperature information 340 and output an estimated maximum temperature of the IMD 112. As an example, the data model 236 may be trained to receive one, two, three, four, five, six, seven, or more inputs such as the heat of the IMD 112 (e.g., heat lost by the IMD 112), the electrical resistance of the IMD 112, the electrical current of the battery of the IMD 112, temperature measurements from the first temperature sensor 230 A, temperature measurements from the second temperature sensor 230B, temperature measurements from the third temperature sensor 230C, and / or temperature measurements from the fourth temperature sensor 230D, and then to output an estimated maximum temperature value of the IMD 112. In one embodiment, the data model 236 may be trained to receive values of the above-mentioned seven inputs over a predetermined period of time or for a predetermined number of measurement cycles (such as when the temperature sensors 230A-230D continuously or periodically generate measurements). For instance, the data model 236 may receive input from the previous four measurement cycles (e.g., data from the previous 6 seconds when the measurement cycle is every 1.5 seconds), such that the data model 236 receives 28 total inputs (e.g., the seven inputs for the four most recent measurement cycles) and then outputs the estimated maximum temperature value of the IMD 112.

[0087] The training data used to train the data model 236 may be or comprise heat data, power data, electrical current data, voltage data, resistance data, and / or temperature data generated or measured by one or more sensors (e.g., the temperature sensors 230A-230D) positioned within or external to the IMD 112. In some cases, the data model 236 may be trained at least partially on temperature data generated by the temperature sensors 230A- 230D. In other words, the data model 236 may be trained to take into account dynamics of the PCB, the connector, and / or the like to estimate the temperature of the IMD 112 or portions thereof. In these cases, the temperature data generated by the temperature sensors 230A-230D may not be the dominant factor in estimating temperature of the IMD 112 orportions thereof, which may in turn beneficially enhance the flexibility of the data model 236 in estimating the maximum temperature of the IMD 112.

[0088] As part of training the data model 236, the training data may pass through the data model 236, and the output of the data model 236 may be labeled for error (e.g., a user indicates the known, correct maximum temperature of the IMD 112 or a portion thereof, a processor compares the output of the data model 236 to the known, correct maximum temperature of the IMD 112 or a portion thereof, etc.). In one example, the error may be the difference between the known, correct maximum temperature of the IMD 112 and the estimated maximum temperature output by the data model 236. The error may then be backpropagated through the data model 236 to iteratively train the data model 236 to generate the output.

[0089] In some cases, the data model 236 may be trained to output the maximum temperature of the IMD 112 based on at least the estimated temperatures of various portions of the IMD 112. In an example according to embodiments of the present disclosure depicted in Fig. 2C, a temperature chart depicts temperature values measured at a variety of positions on the IMD 112, as well as other components of the system 100. The chart depicts a temperature reference (Tref); applied tissue temperature measurements at six different positions proximate the IMD 112 (Tcanl-6) determined, for example, based on data from external thermistors disposed proximate the IMD 112; internal temperature of portions of the IMD 112 (Thybl-b4) measured, for example, by the temperature sensors 230A-230D; temperature of portions of the external charging device 120 (Twr); and the maximum predicted temperature of the IMD 112 determined by the data model 236 (Can: Max Predicted).

[0090] In the example shown in Fig. 2C, the data model 236 may receive one or more inputs and output the highest value of the estimated temperatures. For instance, the data model 236 may receive information about the temperature of each portion of the IMD 112 (e.g., the temperature of the IMD 112 at locations associated with the Thybl-b4 data) along with information about the heat, power, resistance, current, etc. of the IMD 112 and / or the external charging device 120 as input and output the highest value of the estimated temperatures. In the chart in Fig. 2C, at time 435.2, a first portion of the IMD 112 (Tcan4BumpStak) may have the highest temperature relative to the other portions of the IMD 112, and the output of the data model 236 (represented by the “Can: Max Predicted” line) matches the temperature data associated with the first portion of the IMD 112. Later, another portion of the IMD 112 (e.g., the connector portion) may heat up morethan the first portion of the IMD 112, such that the connector portion is the portion of the IMD 112 with the highest temperature. In this case, the estimated temperature output by the data model 236 may correspond to the temperature of the connector. In other words, the data model 236 may accurately track with the hottest portion of the IMD 112. In some examples, the output of the data model 236 may be used as the estimated applied temperature to implement heat and / or temperature control of the IMD 112. For example, the output of the data model 236 may be used as an estimated amount of heat that is applied to an anatomical element proximate the IMD 112.

[0091] The telemetry circuitry 220 supports wireless communication between the IMD 112 and the external charging device 120, an external programmer, another computing device, and / or the like under the control of the processing circuitry 210. The processing circuitry 210 of the IMD 112 may receive, as updates to programs, values for various parameters such as magnitude and electrode combination, from the external charging device 120 via the telemetry circuitry 220. The processing circuitry 210 of the IMD 112 may additionally or alternatively send information (e.g., temperature information recorded by the temperature sensors 224) to the external charging device 120 via the telemetry circuitry 220. The telemetry circuitry 220 in the IMD 112, as well as telemetry modules in other devices and systems described herein, such as the external charging device 120, may accomplish communication by radiofrequency (RF) communication techniques via one or more wireless interfaces (e.g., by transmitting and / or receiving information via one or more wireless communication protocols such as 802.1 la / b / g / n, Bluetooth, NFC, ZigBee, and so forth). In addition, the telemetry circuitry 220 may communicate with an external medical device programmer via proximal inductive interaction of the IMD 112 with the external charging device 120. Accordingly, the telemetry circuitry 220 may send information to and / or receive information from the external charging device 120 on a continuous basis, at periodic intervals, or upon request from the IMD 112 or the external charging device 120.

[0092] The power source 216 delivers operating power to various components of the IMD 112. The power source 216 may include a rechargeable battery and a power generation circuit to produce the operating power of the IMD 112. As previously noted, recharging of the power source 216 may be accomplished through proximal inductive interaction between the coil 128 of the external charging device 120 and the secondary coil 118 of the IMD 112. In some examples, power requirements may be small enough toallow IMD 112 to utilize patient motion and implement a kinetic energy-scavenging device to trickle charge a rechargeable battery.

[0093] The IMD 112 comprises one or more temperature sensors 224. The temperature sensors 224 may measure the temperature of portions of the IMD 112 in which the temperature sensors are positioned. In some instances, the temperature sensors 224 may not be thermally coupled and / or directly attached to portions of the IMD 112 — such as shield of the IMD 112 that interfaces with patient anatomical tissue — for which the temperature is to be determined for the purposes of controlling or monitoring recharging, patient safety, and / or the like. In other words, the readings generated by the temperature sensors 224 may be indirect readings of the anatomical tissues surrounding the IMD 112 when the external charging device 120 is recharging the IMD 112, such that the exact temperature of the patient tissue is unknown.

[0094] The temperature sensors 224 may be positioned on the PCB 232 within the IMD 112. The temperature sensors 224 measure the temperature of any component, surface, and / or structure of the IMD 112 (e.g., the region of the PCB 232 on which the temperature sensor is positioned, the secondary coil 118, the shield of the IMD 112, etc.), and may be disposed internally or externally relative to the IMD 112. As described herein, the measurements from the temperature sensors 224 may be used to estimate a relative position of the IMD 112 from the external charging device 120 (or vice versa) and, based on such position estimation, to estimate the temperature of anatomical tissue surrounding the IMD 112. The estimated temperature of the anatomical tissue — which may be correlated with and / or otherwise correspond to the amount of heat generated by the IMD 112 — may be used by processing circuitry 210 or other processing circuitry or controllers discussed herein to regulate one or more operating parameters of the external charging device 120. For example, by comparing the estimated anatomical temperature to one or more threshold values (e.g., a value associated with the maximum temperature an anatomical element can receive), processing circuitry or controllers may decrease the power output of the external charging device 120 (e.g., to lower the overall heat induced in the secondary coil 118 and / or the IMD 112), send one or more warnings regarding the positioning of the external charging device 120 relative to the IMD 112 (e.g., sending a visual signal, audio signal, haptic signal, combinations thereof, etc. to the external charging device 120 or an external programmer to alert a patient, physician, or the like), and / or the like.

[0095] In one embodiment, the temperature sensors 224 comprise at least four temperature sensors. For example, the temperature sensors 224 may comprise a first temperature sensor 230 A, a second temperature sensor 23 OB, a third temperature sensor 230C, and a fourth temperature sensor 230D. The four temperature sensors 230A-230D may enable the processing circuitry 210 (or other processing circuitry or controllers discussed herein) to estimate the position of the external charging device 120 relative to the IMD 112 (or vice versa) as well as the orientation of the IMD 112 relative to the external charging device 120 (or vice versa). In other words, the use of at least four temperature sensors 230A-230D provides sufficient temperature information to enable the processing circuitry 210 to determine the position of the IMD 112 in a two-dimensional (2D) plane relative to the IMD 112 as well as whether the IMD 112 is in a flipped or nonflipped orientation relative to the external charging device 120. In such examples, the positioning of the temperature sensors 230A-230D on the PCB 232 may generate information that can be used by the processing circuitry 210 to generate z-axis information, which information may enable the processing circuitry 210 to determine whether the IMD 112 is flipped. Additionally or alternatively, the z-axis information may be used with other information (such as recharger power) to determine a depth at which the IMD 112 is implanted within the patient.

[0096] The temperature sensors 224 may be disposed in any pattern or orientation within the IMD 112. In some embodiments, the at least four temperature sensors 230A-230D may be spaced at a maximum distance from every other temperature sensor on the PCB 232 to increase the difference in temperature when the external charging device 120 is off center. In such a cross shape, the first temperature sensor 230A may be disposed at a top of the PCB 232, the second temperature sensor 230B may be disposed at a bottom of the PCB 232, the third temperature sensor 230C may be disposed on a right-hand side of the PCB 232, and the fourth temperature sensor 230D may be disposed on a left-hand side of the PCB 232 (as depicted in Fig. 2B), Such that the overall distance between the sensors is maximized. Similarly, some of the temperature sensors may be positioned within a first area of a housing of the IMD 112 (e.g., the first temperature sensor 230A and the second temperature sensor 230B are positioned on a first surface of the PCB 232 and between the first surface of the PCB 232 and a front surface of the IMD 112), while other temperature sensors are positioned within a second area of the housing of the IMD 112 different from the first area (e.g., the third temperature sensor 230C and the fourth temperature sensor 230D are positioned on a second, opposite surface of the PCB 232 and between the secondsurface of the PCB 232 and a back surface of the IMD 112). Such maximization of the distance between the sensors, as well as the positioning of temperature sensors in different areas of the IMD 112, may beneficially improve the temperature measurements by enabling the temperature sensors 224 to capture temperature measurements associated with a greater area or volume of the IMD 112. Additionally and as previously discussed, the positioning of the temperature sensors in different areas of the IMD 112 may enable the temperature sensors 224 to generate temperature information associated with a depth of the IMD 112. In other words, by placing the temperature sensors 224 at various depths, the temperature sensors 224 may generate multi-dimensional (e.g., 2D or 3D) temperature information that can be used to determine a location of the external charging device 120 relative to the IMD 112 when the IMD 112 is being charged by the external charging device 120.

[0097] The recharge module 228 is coupled to the power source 216 and to the secondary coil 118. The recharge module 228 may be configured to recharge the power source 216 with the current induced in the secondary coil 118. The recharge module 228 may include any of a variety of charging and / or control circuitry configured to process or convert the current induced in the secondary coil 118 into charging current to charge the power source 216. Although the processing circuitry 210 may provide some commands to the recharge module 228, in some examples the recharge module 228 may include processing circuitry sufficient to control one or more aspects of the recharging, such that the processing circuitry 210 does not control the recharge module 228.

[0098] The recharge module 228 may include one or more circuits that process, filter, convert, and / or otherwise transform the electrical signal induced in the secondary coil 118 to an electrical signal capable of recharging the power source 216. For instance, the secondary coil 118 may be induced and generate AC, and the recharge module 228 may include a half-wave rectifier circuit and / or a full-wave rectifier circuit configured to convert the AC to DC for application in the power source 216. In cases where the recharge module 228 comprises both a half-wave and a full-wave rectifier circuit, the recharge module 228 may be switchable between the two circuits to regulate the charging rate of the power source 216, the temperature of the IMD 112, and / or the like.

[0099] With reference to Fig. 3, a block diagram illustrating example components of the external charging device 120 are shown in accordance with embodiments of the present disclosure. While the external charging device 120 is generally described as a hand-held or portable device, the external charging device 120 may be a larger portable device or amore stationary device. In some cases, the external charging device 120 may be part of an external programmer (e.g., a device usable by a patient or a physician to program operation of the IMD 112). The external charging device 120 comprises the patient interface device 124 and the coil 128, which may be connected via a wired connection or wireless connection (e.g., wirelessly linked via a device pairing technology). The patient interface device 124 includes a user interface 302, telemetry circuitry 308, processing circuitry 310, a memory 312, and a power source 316. The coil 128 may include a heat sink 132, one or more temperature sensors 324, and a charging module 332. In some examples, the processing circuitry 310 may be similar to the processing circuitry 210, the telemetry circuitry 308 may be similar to the telemetry circuitry 220, and the power source 316 may be similar to the power source 216.

[0100] The processing circuitry 310 may include fixed function processing circuitry and / or programmable processing circuitry, and may comprise, for example, any one or more of a processor, a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functions attributed to the processing circuitry 310 herein may be embodied as firmware, hardware, software or any combination thereof. The processing circuitry 310 may control one or more components of the patient interface device 124 based on instructions, content, and / or data stored in the memory 312. In some embodiments, the processing circuitry 310 may perform one or more control functions associated with the recharging of the IMD 112, such as by controlling power output by the IMD 112 to maintain a safe temperature of the IMD 112.

[0101] The memory 312 may include any volatile or non-volatile media, such as a random-access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, any memory discussed herein, and / or any other tangible, non-transitory memory for storing computer-readable data and / or instructions. The memory 312 may store computer- readable instructions that, when executed by the processing circuitry 310, cause the external charging device 120 to perform various functions. The memory 312 may be a storage device or other non-transitory medium. The memory 312 may store information or data useful for completing, for example, any step of the methods 600, 700, and / or 800 described herein, or of any other method. The memory 312 may store, for example, instructions and / or machine learning models that support one or more functions of theexternal charging device 120. For instance, the memory 312 may store content (e.g., instructions and / or machine learning models) that, when executed by the processing circuitry 310, adjust one or more operating parameters associated with the external charging device 120 (e.g., the power output of the external charging device 120, the amplitude of current flowing through the coil 128, etc.) to keep the estimated temperature applied to patient tissue below a maximum temperature threshold. Such content, if provided as in instruction, may, in some embodiments, be organized into one or more applications, modules, packages, layers, or engines. Alternatively or additionally, the memory 312 may store other types of content or data (e.g., machine learning models, artificial neural networks, deep neural networks, etc.) that can be processed by the processing circuitry 310 to carry out the various methods and features described herein. Thus, although various contents of memory 312 may be described as instructions, it should be appreciated that functionality described herein can be achieved through use of instructions, algorithms, and / or machine learning models. The data, algorithms, and / or instructions may cause the processing circuitry 310 to manipulate data stored in the memory 312 and / or received from or via the IMD 112, a programming device, and / or the like.

[0102] The memory 312 stores a position algorithm 336. The position algorithm 336 may be or comprise one or more algorithms and / or data models that can be used by the processing circuitry 310 to determine a likely location of the external charging device 120 relative to the IMD 112 (or vice versa), a position or location of a portion of the IMD 112 (e.g., the hottest relative portion of the IMD 112), combinations thereof, and / or the like. The location of hot spots of the IMD 112 may be dependent on the location of the external charging device 120 relative to the IMD 112. Since the patient 102 may manually place the external charging device 120 on the IMD 112 to charge the IMD 112, the positioning of the external charging device 120 relative to the IMD 112 — and subsequent profile of the heat generated by the IMD 112 — may vary with each charge. The position algorithm 336 may receive as input the temperature information 340 (and optionally additional electrical measurements 344) and output a determined location of the external charging device 120 relative to the IMD 112 (or vice versa), a location on the IMD 112 (e.g., a location of the hottest point on the IMD 112), combinations thereof, and / or the like. In some embodiments, the determined location may be rendered or displayed on the user interface 302, sent to the external programmer, stored in memory or a database, and / or the like.

[0103] In some embodiments, the memory 312 may store additional or alternative algorithms that enable the processing circuitry 310 to control operation of the coil 128 to control the induced heat of the IMD 112 and / or the components thereof. For example, the memory 312 may store one or more algorithms that determine an estimated heat induced in the IMD 112, the external charging device 120, and / or the like based on measured input parameters. The measured input parameters may comprise the power sent to the coil 128, the heat lost by the external charging device 120, the housing in which the coil 128 is placed, and / or the coil 128, the voltage and / or current limits of the IMD 112, the current generated by the power source 216 and / or the power source 316, combinations thereof, and / or the like. In some embodiments, the system 100 may implement heat control as discussed in U.S. Patent No. 11,705,763 and / or U.S. Patent No. 11,896,838, both of which are incorporated herein by reference.

[0104] The temperature information 340 may be information associated with temperature measurements generated by the temperature sensors 224 and stored in the memory 312. The temperature information 340 may provide multi-dimensional data of temperature measurements in the IMD 112. Fig. 4 shows example temperature information 340 and electrical measurements 344 according to at least one example embodiment of the present disclosure. The temperature information 340 may comprise, for example, temperature gradients associated with temperature readings captured by the temperature sensors 224. The electrical measurements 344 may comprise information associated with the operation of electrical components in the IMD 112 and / or the external charging device 120, such as the resistance of the external charging device 120 as depicted in Fig. 4. In some cases, the electrical measurements 344 may comprise computed information calculated from readings taken by one or more sensors in the IMD 112 and / or the external charging device 120. For instance, the electrical measurements 344 may comprise efficiency information determined by calculating various ratios (e.g., a ratio of energy stored in the IMD 112 to energy output by the external charging device 120, a ratio of time needed to charge the IMD 112 to the longest time needed to charge the IMD 112, etc.). The temperature information 340 and / or the electrical measurements 344 may in some cases be rendered or displayed on the user interface 302, sent to the external programmer, stored in memory or a database, and / or the like.

[0105] The position algorithm 336 may comprise an objective function that describes a difference or error (e.g., an average of the difference in distance squared) between an initial guess of the position of the external charging device 120 relative to the IMD 112and the actual position of the external charging device 120 relative to the IMD 112. In cases where the position algorithm 336 estimates a point in space of the IMD 112 (e.g., a location associated with the hottest part of the IMD 112), the objective function may describe the difference between the initial guess of the location of the point in space and the actual position of the point in space. The objective function may be iteratively optimized to adjust the initial guess of the external charging device 120 (or in some cases the initial guess of the position of the IMD 112) to converge to the actual position of the external charging device 120 relative to the IMD 112 (or the actual position of the IMD 112). For instance, the objective function may be optimized by applying a gradient descent operator to the temperature information 340 to determine a change in the initial guess that results in a decrease in the difference value output by the objective function. While a gradient descent operator is discussed, it is to be understood that one or more additional or alternative numerical optimization methods (e.g., stochastic gradient descent, Newton’s method, etc.) may be used to minimize (or in some cases maximize) the objective function. The gradient operator may be applied or contain information about one or more dimensions (e.g., ID, 2D, or 3D), such that the position of the external charging device 120 relative to the IMD 112 may be provided in one, two, or three dimensions.

[0106] The minimum or maximum value of the objective function may correspond to a difference between the actual position of the external charging device 120 and the guess or predicted position of the external charging device 120 relative to the IMD 112, and may be determined based on a predetermined threshold value (e.g., a value stored in the memory 312). Additionally or alternatively, the objective function may be considered optimized after a predetermined or selected number of iterations (e.g., after 12 iterations, the position used in the 12th iteration is selected as being optimized), the best fit obtained over a range of iterations (e.g., the objective function is optimized 6 times, and the 4th iteration produces the minimum value, so the position guess in the fourth iteration is used), and / or the like. Any one or more criteria may be used to determine if the objective function has been optimized.

[0107] The memory 312 also comprises one or more charge algorithms 348. The charge algorithm 348 can be used by the processing circuitry 310 to estimate an amount of time needed to fully or partially charge the power source 216 of the IMD 112 based on the estimated position of the IMD 112 and / or the external charging device 120 and the estimated maximum temperature of the IMD 112 (e.g., as output from the data model 236). The charge algorithm 348 may receive as input the estimated position of the IMD112 and / or the external charging device 120 and the estimated maximum temperature of the IMD 112 and output an estimated amount of time to fully or partially recharge the IMD 112. In some embodiments, the estimated amount of time may be displayed on the user interface 302, sent to the external programmer, stored in memory or a database, and / or the like.

[0108] The telemetry circuitry 308 supports wireless communication between the external charging device 120 and the IMD 112, an external programmer, another computing device, and / or the like under the control of the processing circuitry 310. The processing circuitry 310 of the external charging device 120 may receive various measurements or information from the IMD 112 via the telemetry circuitry 308. The processing circuitry 310 of the external charging device 120 may additionally or alternatively receive information (e.g., temperature information recorded by the temperature sensors 224) from the IMD 112 via the telemetry circuitry 308. The telemetry circuitry 308 in the external charging device 120, as well as telemetry modules in other devices and systems described herein, such as the telemetry circuitry 220 of the IMD 112, may accomplish communication by radiofrequency (RF) communication techniques via one or more wireless interfaces (e.g., by transmitting and / or receiving information via one or more wireless communication protocols such as 802.1 la / b / g / n, Bluetooth, NFC, ZigBee, and so forth). In addition, the telemetry circuitry 308 may communicate with an external medical device programmer. Accordingly, the telemetry circuitry 308 may send information to and / or receive information from the IMD 112 on a continuous basis, at periodic intervals, or upon request from the IMD 112 or the external charging device 120.

[0109] The user interface 302 may be or comprise a keyboard, mouse, trackball, monitor, television, screen, touchscreen, and / or any other device for receiving information from a user and / or for providing information to a user. The user interface 302 may be used, for example, to receive a user selection or other user input regarding any step of any method described herein. Notwithstanding the foregoing, any required input for any step of any method described herein may be generated automatically by the system 100 (e.g., by the processing circuitry 310) or received by the system 100 from a source external to the system 100. In some embodiments, the user interface 302 may be useful to allow a physician or other user to modify instructions to be executed by the processing circuitry 310 according to one or more embodiments of the present disclosure, and / or to modify or adjust a setting of other information rendered or displayed on the user interface 302 or corresponding thereto.

[0110] Although the user interface 302 is shown as part of the external charging device 120, in some embodiments, the external charging device 120 may utilize a user interface 302 that is housed separately from one or more remaining components of the external charging device 120. In some embodiments, the user interface 302 may be located proximate one or more other components of the external charging device 120, while in other embodiments, the user interface 302 may be located remotely from one or more other components of the external charging device 120. The temperature sensors 324 may be similar to the temperature sensors 224. The temperature sensors 324 may be disposed within and / or on an outer surface of the coil 128 to capture temperature measurements of the coil 128, the heat sink 132, and / or other components of the external charging device 120.[OHl] The charging module 332 may include one or more circuits that generate an electrical signal and an electrical current within the coil 128. The recharge module 228 may generate AC with a predetermined or specified characteristics (e.g., amplitude, frequency, etc.) based on information stored in the memory 312. In other cases, the recharge module 228 may generate DC. The recharge module 228 may be configured to adjust the operating parameters of the external charging device 120 (e.g., the wattage, electrical current, current amplitude, voltage amplitude, pulse rate, pulse width, duty cycle, combinations thereof, etc.) by changing corresponding characteristics of the current passing through the coil 128 (and subsequently the magnetic field generated by the coil 128 to inductively charge the secondary coil 118). In some embodiments, the recharge module 228 may be controlled by the processing circuitry 310 to generate a specified current to limit or otherwise control the amount of heat generated by the IMD 112 and passed into anatomical tissues adjacent to the IMD 112 when the IMD 112 is being charged by the external charging device 120.

[0112] The power source 316 may be similar to the power source 216 in that the power source 316 provides energy to one or more components of the external charging device 120. In one embodiment, the power source 316 may provide power to the charging module 332 to drive the coil 128 when the external charging device 120 is charging the IMD 112. The power source 316 may be rechargeable or non-rechargeable. In some embodiments, the power source 316 may be separate from the external charging device 120 and / or may draw power from an external power source (e.g., a power outlet).

[0113] Fig. 6 depicts a method 600 that may be used, for example, to control heat generated when an IMD is charged.

[0114] The method 600 (and / or one or more steps thereof) may be carried out or otherwise performed, for example, by processing circuitry (e.g., processing circuitry 210, processing circuitry 310, etc.). Processing circuitry other than the processing circuitry described herein may also be used to execute the method 600. The processing circuitry may perform the method 600 by executing elements stored in a memory such as the memory 212 or the memory 312. The elements stored in memory and executed by the processing circuitry may cause the processing circuitry to execute one or more steps of a function as shown in method 600. One or more portions of a method 600 may be performed by the processor executing any of the contents of memory, such as the data model 236, the position algorithm 336, the temperature information 340, the electrical measurements 344, and / or the charge algorithm 348.

[0115] The method 600 comprises setting operating parameter(s) of a recharging device (step 604). The recharging device may be similar to or the same as the external charging device 120. The operating parameters may be associated with the power, current, magnetic field, and / or the like delivered by the coil 128 when the external charging device 120 is inductively coupled with the secondary coil 118 of the IMD 112. In some embodiments, the initial operating parameters may be based on predetermined values (e.g., values stored in the memory 212 and / or the memory 312). Once the initial parameters are set, the patient may hold the recharging device on their skin, such that the external charging device 120 wirelessly charges the IMD 112.

[0116] The method 600 also comprises receiving temperature information from temperature sensors (step 608). As the external charging device 120 wirelessly charges the IMD 112, temperature sensors in the IMD 112 (e.g., temperature sensors 224) generate temperature readings that are sent to the external charging device 120 via the telemetry circuitry 220 / telemetry circuitry 308 and stored in the memory 312 as temperature information 340. In some embodiments, the temperature sensors may be maximally spaced apart (e.g., in a cross configuration when there are four temperature sensors) and / or spaced apart along a depth of the IMD 112, such that the temperature information 340 comprises temperature readings for two or three spatial dimensions. In some embodiments, additional sensors in the IMD 112 (e.g., voltmeters, ammeters, etc.) may generate electrical measurements 344 that are also sent to the external charging device 120 and stored in the memory 312.

[0117] The method 600 also comprises estimating, based on the received temperature information, position information associated with at least one of the recharger and theimplanted device (step 612). The processing circuitry 310 may use the position algorithm 336 to estimate the position of the external charging device 120 relative to the IMD 112. Additionally or alternatively, the processing circuitry 310 may use the position algorithm 336 to estimate a location of a point in space (e.g., 2D or three-dimensional (3D)) on the IMD 112, such as the location of the hottest part of the IMD 112. In some embodiments, the position algorithm 336 may take the temperature information 340 and the electrical measurements 344 as inputs and, based on a minimization of an objective function, output a determined location of the external charging device 120 relative to the IMD 112, or the determined point in space of the IMD 112. In some embodiments, such as when the temperature sensors 224 comprises at least four temperature sensors, the position algorithm 336 may output an indicator as to whether the IMD 112 is flipped relative to the external charging device 120. In other words, the position algorithm 336 may indicate if the coil 128 is oriented in such a way that one or more electrical components of the IMD 112 are positioned between the external charging device 120 and the IMD 112 (which may lead to less efficient charging). In some embodiments, the estimated position of the external charging device 120, information as to whether the IMD 112 is flipped, and the like may be rendered or output to the user interface 302 of the external charging device 120, an external programmer, and / or the like.

[0118] The method 600 also comprises estimating, based on the position information, a maximum applied temperature to an anatomical element (step 616). The processing circuitry 310 may further estimate the maximum applied temperature to anatomical tissues surrounding or near the IMD 112 based on the estimated position of the external charging device 120 relative to the IMD 112 and the temperature information 340. For example, a first sensor positioned on the top of the PCB 232 of the IMD 112 (e.g., the edge of the PCB 232 closest to the head of the patient) may have the highest temperature reading, and the position algorithm 336 may have determined that the external charging device 120 is offset 1 centimeter (cm) from the optimal coupling position. As a result, the processing circuitry 310 may determine that the hottest spot (and subsequently the maximum applied temperature to adjacent anatomical tissues) is at the top of the PCB 232 of the IMD 112. The processing circuitry 310 may then regulate, adjust, or otherwise control the operating parameters of the external charging device 120 to ensure that the maximum applied temperature (e.g., the temperature measurement associated with the first sensor) remains below a threshold value.

[0119] In some cases, the processing circuitry 310 may estimate the maximum applied temperature to the anatomical tissues based on outputs from the data model 236. For example, the data model 236 may output an estimated maximum temperature of the IMD 112 (or a portion thereof such as the top of the PCB 232) as well as a value or label identifying the portion of the IMD 112 associated with the estimated maximum temperature. In this example, the two outputs of the data model 236 (e.g., the estimated maximum temperature value and the location of the hottest spot of the IMD 112) may be used by the processing circuitry 310 to estimate the maximum applied temperature to anatomical tissues around the IMD 112.

[0120] The method 600 also comprises determining if the estimated applied temperature meets or exceeds a threshold value (step 620). When the processing circuitry 310 determines the maximum applied temperature, the processing circuitry 310 may continually monitor temperature information 340 generated by the temperature sensors 224, and adjust the operating parameters of the external charging device 120 accordingly to ensure that the maximum applied temperature falls below the threshold value. The processing circuitry 310 may continuously compare the maximum applied temperature to the threshold value and, when the temperature meets or exceeds the threshold value, the processing circuitry 310 may adjust the operating parameters of the external charging device 120, generate one or more alerts that are displayed on the user interface 302 and / or sent to an external programmer, combinations thereof, and / or the like.

[0121] With reference to Figs. 5A and 5B, charts depicting battery current and maximum applied temperature over time are shown in accordance with embodiments of the present disclosure when the external charging device 120 is in a respective mediocre position (e.g., a position where charging occurs but where unnecessary and excess heat is generated) and poor position (e.g., a position where unnecessary and excess heat is generated and where charging may take double the amount of time as when the external charging device 120 is in an optimal position). As depicted in Figs. 5A-5B, the maximum applied temperature may be based on a threshold value (e.g., 42.5 degrees Celsius) stored in the memory 312 and accessed by the processing circuitry 310. When the threshold value is met or exceeded, the processing circuitry 310 implements adjustments to the operating parameters of the external charging device 120 to lower the maximum applied temperature (e.g., a temperature measurement associated with the temperature sensor that the processing circuitry 310 has identified as the best representation of the temperature of the adjacent or surrounding anatomical tissue). The charts depict both heat control (e.g., wheretransfer functions are used to adjust for the heat limit of the IMD 112) and temperature control (e.g., where the processing circuitry 310 monitors the temperature information 340 to ensure the maximum applied temperature does not exceed the threshold value). By implementing temperature control, embodiments of the present disclosure beneficially enhance charging times when the external charging device 120 is in less-than-optimal positions relative to the IMD 112 when compared to implementation of heat control.

[0122] The method 600 also comprises adjusting operating param eter(s) to maintain a safe temperature (step 624). The operating parameters of the external charging device 120 may be changed by the processing circuitry 310, which may control the charging module 332 to change the characteristics of the power supplied to the coil 128, the current flowing through the coil 128, the magnetic field generated by the coil 128, and / or the like. For example, the processing circuitry 310 may decrease the power output by the external charging device 120 when the temperature meets or exceeds the threshold level. In some embodiments, the processing circuitry 310 may adjust the operating parameters by disabling one or more components in the external charging device 120 until the monitored temperature drops below the threshold value. The processing circuitry 310 may implement one or more control loop mechanisms such as proportional-integral-derivative (PID) controllers or the like. In some embodiments, the processing circuitry 310 may continuously monitor temperature until the IMD 112 is full (e.g., fully charged), for a predetermined amount of time, until the user discontinues charging the IMD 112, combinations thereof, and / or the like.

[0123] The present disclosure encompasses embodiments of the method 600 that comprise more or fewer steps than those described above, and / or one or more steps that are different than the steps described above.

[0124] Fig. 7 depicts a method 700 that may be used, for example, to control an IMD charging based on estimated induced heat of the IMD.

[0125] The method 700 (and / or one or more steps thereof) may be carried out or otherwise performed, for example, by processing circuitry (e.g., processing circuitry 210, processing circuitry 310, etc.). Processing circuitry other than the processing circuitry described herein may also be used to execute the method 700. The processing circuitry may perform the method 700 by executing elements stored in a memory such as the memory 212 or the memory 312. The elements stored in memory and executed by the processing circuitry may cause the processing circuitry to execute one or more steps of a function as shown in method 700. One or more portions of a method 700 may beperformed by the processor executing any of the contents of memory, such as the data model 236, the position algorithm 336, the temperature information 340, the electrical measurements 344, and / or the charge algorithm 348.

[0126] The method 700 comprises estimating heat induced in an IMD (step 704). The processing circuitry 310 may use one or more algorithms stored in the memory 312 to estimate the heat induced in the IMD (which may be similar to or the same as the IMD 112). The one or more algorithms may receive information about the power sent to the coil 128, the heat lost by the coil 128, the voltage and / or current limits of the IMD 112, the current generated by the power source 216 and / or the power source 316, combinations thereof, and / or the like as inputs, and may output an estimated heat induced in the IMD 112. For example, the algorithm may estimate the heat induced in the IMD 112 by subtracting both the heat generated by the coil 128 of the external charging device 120 and the power stored in the power source of the IMD 112 from the power sent to the coil 128 of the external charging device 120. In some embodiments, the estimated heat induced may be stored in the memory 212 and / or the memory 312.

[0127] The method 700 also comprises determining if the estimated induced heat exceeds a threshold value (step 708). When the processing circuitry 310 determines the estimated heat induced in the IMD 112, the processing circuitry 310 may continually generate an estimated induced heat based on measurements generated by one or more sensors in the system 100. The processing circuitry 310 may continuously or periodically compare the estimated induced heat to the threshold value and, when the induced heat meets or exceeds the threshold value, adjust the operating parameters of the external charging device 120, generate one or more alerts that are displayed on the user interface 302 and / or sent to the external programmer, combinations thereof, and / or the like.

[0128] In some cases, the operating parameters of the external charging device 120 being adjusted based on a combination of estimated temperatures and induced heat values. As depicted in Fig. 7, the method 700 may comprise adjusting operating parameters of the external charging device 120 when the estimated applied temperature to the anatomical element proximate the IMD 112 exceeds a threshold temperature value, as discussed in the step 620, and / or when the estimated induced heat in the IMD 112 exceeds a threshold heat value, as discussed in the step 708. In some embodiments, both the threshold value for the estimated temperature of the anatomical element proximate the IMD 112 and the threshold value for the estimated induced heat in the IMD 112 may be stored in the memory 212 and / or the memory 312.

[0129] The present disclosure encompasses embodiments of the method 700 that comprise more or fewer steps than those described above, and / or one or more steps that are different than the steps described above.

[0130] Fig. 8 depicts a method 800 that may be used, for example, to estimate a time to fully or partially recharge an IMD based on an estimated position of the IMD.

[0131] The method 800 (and / or one or more steps thereof) may be carried out or otherwise performed, for example, by processing circuitry (e.g., processing circuitry 210, processing circuitry 310, etc.). Processing circuitry other than the processing circuitry described herein may also be used to execute the method 800. The processing circuitry may perform the method 800 by executing elements stored in a memory such as the memory 212 or the memory 312. The elements stored in memory and executed by the processing circuitry may cause the processing circuitry to execute one or more steps of a function as shown in method 800. One or more portions of a method 800 may be performed by the processor executing any of the contents of memory, such as the data model 236, the position algorithm 336, the temperature information 340, the electrical measurements 344, and / or the charge algorithm 348.

[0132] The method 800 comprises estimating a time to recharge an implanted device (step 804). In some cases, the implanted device may be or comprise an IMD such as the IMD 112. The processing circuitry 310 may use one or more algorithms stored in the memory 312, along with information about the estimated position of the IMD 112, to estimate an amount of time needed to recharge the IMD. In one example, the step 804 of the method 800 proceeds from step 612, where position information associated with at least one of the recharger and the implanted device is estimated. The processing circuitry 310 may use the charge algorithm 348 (or similar algorithm) to estimate the time to recharge (e.g., completely or partially) the power source 216 of the IMD 112. The charge algorithm 348 may take the estimated position information of the implanted device and / or the recharger device as inputs and output an estimated time to fully charge the power source 216. Additionally or alternatively, the charge algorithm 348 may output an amount of time needed to partially charge the power source 216 (e.g., amount of time to charge the power source 216 to 25%, 50%, 75%, 90%, 95%, etc.). The charge algorithm 348 may estimate the amount of time needed based on the estimated maximum temperature of the IMD 112 (which may be based on one or more outputs from the data model 236) and the estimated positions of the implanted device and / or the recharger device. For instance, when the estimated maximum temperature of the IMD 112 exceeds a threshold value, thecharge algorithm 348 may determine that the charging is less than optimal, and may increase the estimated amount of time. In some cases, the charge algorithm 348 may use historical data of charging times that take into account similar implanted device and recharger positions, as well as maximum temperature values, to estimate the amount of time required to fully or partially recharge the implanted device.

[0133] The method 800 also comprises rendering the time to recharge the implanted device to a display (step 808). The processing circuitry 310 may render the amount of time output by the charge algorithm 348 to a display (e.g., a display on the user interface 302). In some cases, the steps 804 and 808 may repeat periodically or continuously to provide updates on the estimated time needed to fully or partially recharge the implanted device. In some cases, such as when a patient is repositioning the charging device, the charge algorithm 348 may provide updated information of the estimated time to recharge the implanted device, beneficially enabling the user to position the recharging device for improved charging.

[0134] As noted above, the present disclosure encompasses methods with fewer than all of the steps identified in Figs. 6, 7, and 8 (and the corresponding description of the methods 600, 700, and 800), as well as methods that include additional steps beyond those identified in Figs. 6, 7, and 8 (and the corresponding description of the methods 600, 700, and 800). The present disclosure also encompasses methods that comprise one or more steps from one method described herein, and one or more steps from another method described herein. Any correlation described herein may be or comprise a registration or any other correlation.

[0135] 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, embodiments, and / or configurations for the purpose of streamlining the disclosure. The features of the aspects, embodiments, and / or configurations of the disclosure may be combined in alternate aspects, embodiments, 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, embodiment, 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 embodiment of the disclosure.

[0136] Moreover, though the foregoing has included description of one or more aspects, embodiments, 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, embodiments, 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.

[0137] A set of example statements are provided below:

[0138] Statement 1 : A system, comprising: a processor (210, 310); and a memory (212, 312) storing data thereon that, when processed by the processor (210, 310), enable the processor (210, 310) to: receive temperature information (340) associated with an implanted device (112) configured to be charged by a recharger (120); estimate, based on the temperature information (340), position information associated with at least one of the recharger (120) and the implanted device (112); estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted device (112); and control, based on the estimated temperature, at least one operating parameter of the recharger (120).

[0139] Statement 2: The system of Statement 1, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: decrease a power output of the recharger (120) when the temperature applied to the anatomical element meets or exceeds a threshold value.

[0140] Statement 3: The system of any of Statements 1-2, wherein estimating the position information associated with at least one of the recharger (120) and the implanted device (112) comprises applying a gradient descent operator to the temperature information (340).

[0141] Statement 4: The system of any of Statements 1-3, wherein the temperature information (340) is received from at least four temperature sensors (224, 230A-230D).

[0142] Statement 5: The system of Statement 4, wherein the at least four temperature sensors (224, 230A-230D) are positioned in a cross pattern in the implanted device (112).

[0143] Statement 6: The system of any of Statements 4-5, wherein a first sensor (230A) and a second sensor (230B) of the at least four temperature sensors (224, 230A-230D) are positioned within a first area of a housing of the implanted device (112), and wherein athird sensor (23 OC) and a fourth sensor (23 OD) of the at least four temperature sensors (224, 230A-230D) are positioned within a second area of the housing different from the first area.

[0144] Statement 7: The system of any of Statements 1-6, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: render, to a user interface (302), information associated with at least one of the temperature information (340), the estimated temperature, and the at least one operating parameter of the recharger (120).

[0145] Statement 8: The system of any of Statements 1-7, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: disable operation of the recharger (120) when at least one of an energy storage device (216) of the implanted device (112) is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

[0146] Statement 9: The system of any of Statements 1-8, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: estimate a heat associated with the implanted device (112); and control, based on the estimated heat, the at least one operating parameter of the recharger (120).

[0147] Statement 10: The system of any of Statements 1-9, wherein the position information comprises a position of the recharger (120) relative to the implanted device (H2).

[0148] Statement 11 : The system of any of Statements 1-10, wherein the position information comprises a location on the implanted device (112).

[0149] Statement 12: The system of Statement 11, wherein the location comprises a point in two-dimensional (2D) or three-dimensional (3D) space.

[0150] Statement 13: A system, comprising: a recharger device (120) configured to recharge an implanted medical device (112); a processor (210, 310); and a memory (212, 312) storing data thereon that, when processed by the processor (210, 310), enable the processor (210, 310) to: receive temperature information (340) associated with the implanted medical device (112); estimate, based on the temperature information (340), position information associated with at least one of the recharger device (120) and the implanted medical device (112); estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted medical device (112); and control, based on the estimated temperature, at least one operating parameter of the recharger device (120).

[0151] Statement 14: The system of Statement 13, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: decrease a power output of the recharger device (120) when the temperature applied to the anatomical element meets or exceeds a threshold value.

[0152] Statement 15: The system of any of Statements 13-14, wherein estimating the position information associated with at least one of the recharger device (120) and the implanted medical device (112) comprises applying a gradient descent operator to the temperature information (340).

[0153] Statement 16: The system of any of Statements 13-15, wherein the temperature information (340) is received from at least four temperature sensors (224, 230A-230D).

[0154] Statement 17: The system of Statement 16, wherein the at least four temperature sensors (224, 230A-230D) are positioned in a cross pattern in the implanted medical device (112).

[0155] Statement 18: The system of any of Statements 16-17, wherein a first sensor (230 A) and a second sensor (230B) of the at least four temperature sensors (224, 230A- 230D) are positioned within a first area of a housing of the implanted medical device (112), and wherein a third sensor (230C) and a fourth sensor (230D) of the at least four temperature sensors (224, 230A-230D) are positioned within a second area of the housing different from the first area.

[0156] Statement 19: The system of any of Statements 13-18, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: render, to a user interface (302), information associated with at least one of the temperature information (340), the estimated temperature, and the at least one operating parameter of the recharger device (120).

[0157] Statement 20: The system of any of Statements 13-19, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: disable operation of the recharger device (120) when at least one of an energy storage device (216) of the implanted medical device (112) is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

[0158] Statement 21 : The system of any of Statements 13-20, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: estimate a heat associated with the implanted medical device (112); and control, based on the estimated heat, the at least one operating parameter of the recharger device (120).

[0159] Statement 22: The system of any of Statements 13-21, wherein the position information comprises a position of the recharger device (120) relative to the implanted medical device (112).

[0160] Statement 23: The system of any of Statements 13-22, wherein the position information comprises a location on the implanted medical device (112).

[0161] Statement 24: The system of Statement 23, wherein the location comprises a point in two-dimensional (2D) or three-dimensional (3D) space.

[0162] Statement 25: A method, comprising: receiving temperature information (340) associated with an implanted device (112) configured to be charged by a recharger (120); estimating, based on the temperature information (340), position information associated with at least one of the recharger (120) and the implanted device (112); estimating, based on the position information, a temperature applied to an anatomical element proximate the implanted device (112); and controlling, based on the estimated temperature, at least one operating parameter of the recharger (120).

[0163] Statement 26: The method of Statement 25, further comprising: decreasing a power output of the recharger (120) when the temperature applied to the anatomical element meets or exceeds a threshold value.

[0164] Statement 27: The method of any of Statements 25-26, wherein the temperature information (340) is received from at least four temperature sensors (224, 230A-230D) positioned in a cross pattern in the implanted device (112).

[0165] Statement 28: The method of any of Statements 25-27, further comprising: disabling operation of the recharger (120) when at least one of an energy storage device (216) of the implanted device (112) is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

[0166] Statement 29: The method of any of Statements 25-28, further comprising: estimating a heat associated with the implanted device (112); and controlling, based on the estimated heat, the at least one operating parameter of the recharger (120).

[0167] Statement 30: The method of any of Statements 25-29, wherein the position information comprises a position of the recharger (120) relative to the implanted device (H2).

[0168] Statement 31 : The method of any of Statements 25-30, wherein the position information comprises a location on the implanted device (112).

[0169] Statement 32: The method of Statement 31, wherein the location comprises a point in two-dimensional (2D) or three-dimensional (3D) space.

Claims

CLAIMSWhat is claimed is:

1. A system, comprising: a processor (210, 310); and a memory (212, 312) storing data thereon that, when processed by the processor (210, 310), enable the processor (210, 310) to: receive temperature information (340) associated with an implanted device (112) configured to be charged by a recharger (120); estimate, based on the temperature information (340), position information associated with at least one of the recharger (120) and the implanted device (112); estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted device (112); and control, based on the estimated temperature, at least one operating parameter of the recharger (120).

2. The system of claim 1, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: decrease a power output of the recharger (120) when the temperature applied to the anatomical element meets or exceeds a threshold value.

3. The system of any of claims 1-2, wherein estimating the position information associated with at least one of the recharger (120) and the implanted device (112) comprises using an objective function trained with a gradient descent operator to estimate the temperature information (340).

4. The system of any of claims 1-3, wherein the temperature information (340) is received from at least four temperature sensors (224, 230A-230D).

5. The system of claim 4, wherein the at least four temperature sensors (224, 230A-230D) are positioned in a cross pattern in the implanted device (112).

6. The system of any of claims 4-5, wherein a first sensor (230A) and a second sensor (230B) of the at least four temperature sensors (224, 230A-230D) arepositioned within a first area of a housing of the implanted device (112), and wherein a third sensor (23 OC) and a fourth sensor (23 OD) of the at least four temperature sensors (224, 230A-230D) are positioned within a second area of the housing different from the first area.

7. The system of any of claims 1-6, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: render, to a user interface (302), information associated with at least one of the temperature information (340), the estimated temperature, and the at least one operating parameter of the recharger (120).

8. The system of any of claims 1-7, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: disable operation of the recharger (120) when at least one of an energy storage device (216) of the implanted device (112) is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

9. The system of any of claims 1-8, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: estimate a heat associated with the implanted device (112); and control, based on the estimated heat, the at least one operating parameter of the recharger (120).

10. The system of any of claims 1-9, wherein the position information comprises a position of the recharger (120) relative to the implanted device (112).

11. The system of any of claims 1-10, wherein the position information comprises a location on the implanted device (112).

12. The system of claim 11, wherein the location comprises a point in two- dimensional (2D) or three-dimensional (3D) space.

13. The system of claim 1, wherein the estimated temperature applied to the anatomical element is generated by a data model (236).

14. The system of claim 13, wherein the data model (236) receives heat information of the implanted device (112), resistance information of the implanted device (112), electrical current information of the implanted device (112), and the temperature information (340) as inputs and outputs an estimated maximum temperature of the implanted device (112).

15. The system of claim 1, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: estimate, based on the estimated position information, a time until an energy storage device (216) of the implanted device (112) is fully or partially recharged.

16. A system, comprising: a recharger device (120) configured to recharge an implanted medical device (H2); a processor (210, 310); and a memory (212, 312) storing data thereon that, when processed by the processor (210, 310), enable the processor (210, 310) to: receive temperature information (340) associated with the implanted medical device (112); estimate, based on the temperature information (340), position information associated with at least one of the recharger device (120) and the implanted medical device (112); estimate, based on the position information, a temperature applied to an anatomical element proximate the implanted medical device (112); and control, based on the estimated temperature, at least one operating parameter of the recharger device (120).

17. The system of claim 16, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: decrease a power output of the recharger device (120) when the temperature applied to the anatomical element meets or exceeds a threshold value.

18. The system of any of claims 16-17, wherein estimating the position information associated with at least one of the recharger device (120) and the implanted medical device (112) comprises using an objective function trained with a gradient descent operator to estimate the temperature information (340).

19. The system of any of claims 16-18, wherein the temperature information (340) is received from at least four temperature sensors (224, 230A-230D).

20. The system of claim 19, wherein the at least four temperature sensors (224, 230A-230D) are positioned in a cross pattern in the implanted medical device (112).

21. The system of any of claims 19-20, wherein a first sensor (230A) and a second sensor (230B) of the at least four temperature sensors (224, 230A-230D) are positioned within a first area of a housing of the implanted medical device (112), and wherein a third sensor (230C) and a fourth sensor (230D) of the at least four temperature sensors (224, 230A-230D) are positioned within a second area of the housing different from the first area.

22. The system of any of claims 16-21, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: render, to a user interface (302), information associated with at least one of the temperature information (340), the estimated temperature, and the at least one operating parameter of the recharger device (120).

23. The system of any of claims 16-22, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: disable operation of the recharger device (120) when at least one of an energy storage device (216) of the implanted medical device (112) is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

24. The system of any of claims 16-23, wherein the data, when processed by the processor (210, 310), further enable the processor (210, 310) to: estimate a heat associated with the implanted medical device (112); andcontrol, based on the estimated heat, the at least one operating parameter of the recharger device (120).

25. The system of any of claims 16-24, wherein the position information comprises a position of the recharger device (120) relative to the implanted medical device (H2).

26. The system of any of claims 16-25, wherein the position information comprises a location on the implanted medical device (112).

27. The system of claim 26, wherein the location comprises a point in two- dimensional (2D) or three-dimensional (3D) space.

28. A method, comprising: receiving temperature information (340) associated with an implanted device (112) configured to be charged by a recharger (120); estimating, based on the temperature information (340), position information associated with at least one of the recharger (120) and the implanted device (112); estimating, based on the position information, a temperature applied to an anatomical element proximate the implanted device (112); and controlling, based on the estimated temperature, at least one operating parameter of the recharger (120).

29. The method of claim 28, further comprising: decreasing a power output of the recharger (120) when the temperature applied to the anatomical element meets or exceeds a threshold value.

30. The method of any of claims 28-29, wherein the temperature information (340) is received from at least four temperature sensors (224, 230A-230D) positioned in a cross pattern in the implanted device (112).

31. The method of any of claims 28-30, further comprising:disabling operation of the recharger (120) when at least one of an energy storage device (216) of the implanted device (112) is full and the temperature applied to the anatomical element meets or exceeds a threshold value.

32. The method of any of claims 28-31, further comprising: estimating a heat associated with the implanted device (112); and controlling, based on the estimated heat, the at least one operating parameter of the recharger (120).

33. The method of any of claims 28-32, wherein the position information comprises a position of the recharger (120) relative to the implanted device (112).

34. The method of any of claims 28-33, wherein the position information comprises a location on the implanted device (112).

35. The method of claim 34, wherein the location comprises a point in two- dimensional (2D) or three-dimensional (3D) space.

Images