Implantable medical device including wireless charging

Abstract

A system includes a device and a charger. The device includes a wireless receiver to receive power for the device. The charger includes a wireless transmitter and a control portion. The wireless transmitter transmits the power to the wireless receiver of the device and includes an array of coils. The control portion is configured to determine an amplitude and phase for each coil of the array of coils.

Description

IMPLANTABLE MEDICAL DEVICE INCLUDING WIRELESS CHARGINGBackground

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

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

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

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

[0005] FIGS. 2A-2C are block diagrams schematically representing example systems including an implantable medical device (IMD) and an external charger.

[0006] FIGS. 3A-3D are diagrams schematically representing example devices (e.g., IMDs) including a wireless communication portion.

[0007] FIG. 4 is a diagram schematically representing an example antenna including three orthogonal coils that may be configured to receive wireless power.

[0008] FIG. 5 is a cross-sectional view schematically representing an example antenna including a coil arranged around a power element that may be configured to receive wireless power.

[0009] FIG. 6 is a cross-sectional view schematically representing an example antenna including a coil arranged around an interior of a housing that may be configured to receive wireless power.

[0010] FIGS. 7A-7F are top views schematically representing example antennas including an array of coils arranged to transmit wireless power.

[0011] FIGS. 8A and 8B are top views schematically representing example coil structures that may be configured to wirelessly transmit power to a device.

[0012] FIG. 9 is a top view schematically representing an example coil arrangement of an external charger.

[0013] FIGS. 10A-10E are flow diagrams schematically representing example methods for configuring a charger for wirelessly transmitting power to a device.

[0014] FIG. 1 1 is a flow diagram schematically representing an example method for configuring a charger for wirelessly transmitting power to a device.

[0015] FIGS. 12A-12E are tables illustrating examples of calibration pulse weights for a plurality of calibration pulses that may be transmitted to a device from a charger to configure the charger for wireless power transfer to a device.

[0016] FIGS. 13A and 13B are diagrams schematically representing example systems for configuring a charger for wirelessly transmitting power to a device.

[0017] FIG. 14 is a diagram schematically representing magnetic fields generated by two coils of a charger projected over a device.

[0018] FIG. 15 is a flow diagram schematically representing an example method for configuring a charger for wirelessly transmitting power to a device.

[0019] FIG. 16 is a flow diagram schematically representing an example method for configuring a charger for wirelessly transmitting power to a device.

[0020] FIG. 17 is a table illustrating example calibration pulse weights for a plurality of calibration pulses that may be transmitted to a device from a charger to configure the charger for wireless power transfer to the device.

[0021] FIGS. 18A-18C are signal diagrams schematically representing example signals that may be received by a device in response to calibration pulses from a charger.

[0022] FIGS. 19-22 are tables illustrating examples of calibration pulse weights for a plurality of calibration pulses that may be transmitted to a device from a charger to configure the charger for wireless power transfer to the device.

[0023] FIG. 23 is a signal diagram schematically representing example signals that may be received by a device in response to calibration pulses from a charger.

[0024] FIGS. 24A and 24B are block diagrams schematically representing example control portions.

[0025] FIG. 25 is a block diagram schematically representing an example user interface.

[0026] FIG. 26 is a block diagram schematically representing example communication arrangements between an IMD and external devices.Detailed Description

[0027] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized, and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise.

[0028] At least some examples of the present disclosure are directed to devices for diagnosis, therapy, and / or other care of medical conditions. At least some examples may comprise implantable devices and / or methods comprising use of implantable devices. However, in some examples, the methods and / or devices may comprise at least some external components. In some examples, a therapeutic medical device may comprise a combination of implantable components and external components.

[0029] At least some of the example devices and / or example methods may relate to sleep disordered breathing (SDB) care, which may comprise monitoring, diagnosis, evaluation, and / or treatment, which may comprise stimulation in some examples. At least some examples include devices for sensing, stimulation, and / or communication (e.g., for diagnosis, evaluation, and / or treatment of SDB) which may be performed in combination with or independently from an associated implantable medical device. Among other target tissues for stimulation and / or sensing, at least some target tissues comprise tissues of the head and / or neck regions which include nerves, muscles, and / or other tissues (e.g., tendons,bones, cartilage, etc.) related to treating sleep disordered breathing such as, but not limited to, obstructive sleep apnea. These target tissues may directly or indirectly relate to promoting upper airway patency. In some examples, the target tissues for promoting upper airway patency (e.g., upper airway patency-related tissues) may comprise a hypoglossal nerve, a genioglossus muscle, an infrahyoid muscle (IHM)-innervating nerve, and / or infrahyoid muscles. In some examples, other non-upper airway respiratory-related tissues comprise a phrenic nerve and / or diaphragm muscle, which may be sensed and / or stimulated separately from, and / or in conjunction with, sensing and / or stimulation of upper airway patency-related tissues as part of treating sleep disordered breathing (including obstructive sleep apnea).

[0030] In some examples, the example medical devices, components, etc. may be used in monitoring, evaluation, diagnosis, treatment, etc. of other patient conditions, at least some of which may be treatable via nerve stimulation (and / or innervated muscles). Other target tissues may include those tissues relating to treating pelvic disorders such as (but not limited to) treating urinary and / or fecal incontinence.

[0031] At least some examples include implantable medical devices including a wireless receiver to receive power from an external charger via inductive wireless power transfer (e.g., 50-1000 KHz) or radio frequency (RF) wireless power transfer (e.g., near-field 1 -50 MHz). Some examples include implantable medical devices including a power element that may be recharged by an external charger via inductive wireless power transfer or radio frequency (RF) wireless power transfer.

[0032] These examples, and additional examples, are further described in association with at least FIGS. 1 A-26.

[0033] FIG. 1 A is a block diagram schematically representing an example arrangement 50 (an example device and / or example method) including an implantable medical device (IMD) 52 in operable relation to target tissue(s) 60. In some examples, the IMD 52 may comprise a sensing element 54, a stimulation element 56, and / or other element 58 (or function) such that the IMD 52 may be insensing relation, stimulating relation, and / or other relation with the target tissue(s) 60.

[0034] FIG. 1 B is a block diagram schematically representing a patient’s body 100, including example target portions 110-134 at which at least some example sensing element(s), stimulation element(s), and / or other elements may be employed to implement at least some examples of the present disclosure.

[0035] As shown in FIG. 1 B, patient’s body 100 comprises a head-and-neck portion 1 10, including head 1 12 and neck 1 14. Head-and-neck portion 1 10 comprises cranial tissue, nerves, etc., and upper airway 116 (e.g., nerves, muscles, tissues), etc. As further shown in FIG. 1 B, the patient’s body 100 comprises a torso 120, which comprises various organs, muscles, nerves, other tissues, such as but not limited to those in pectoral region 122 (e.g., lungs 126, cardiac 127), abdomen 124, and / or pelvic region 129 (e.g., urinary / bladder, anal, reproductive, etc.). As further shown in FIG. 1 B, the patient’s body 100 comprises limbs 130, such as arms 132 and legs 134.

[0036] It will be understood that various sensing elements (and / or stimulation elements) as described throughout the various examples of the present disclosure may be deployed within the various regions of the patient’s body 100 to sense and / or otherwise diagnose, monitor, treat various physiologic conditions such as, but not limited to those examples described below in association with FIGS. 2A-26. In some such examples, a stimulation element 1 17 may be located in or near the upper airway 116 for treating sleep disordered breathing (and / or near other nerves / muscles for treating other conditions) and / or a sensing element 128 may be located anywhere within the neck 114, head 112, and / or torso 120 (or other body regions) to sense physiologic information for providing patient care (e.g., SDB, other) and / or for other purposes.

[0037] In some examples, at least a portion of the stimulation element 1 17 may comprise part of an implantable component / device, such as an implantable pulse generator (IPG) whether full sized or sized as a microstimulator. The implantable components (e.g., IPG, other) may comprise a stimulation / control circuit, a power supply (e.g., non-rechargeable, rechargeable), communication elements, and / or other components. In some examples, the stimulation element 1 17 also maycomprise a stimulation electrode and / or stimulation lead connected to the implantable pulse generator.

[0038] Further details regarding the location, structure, operation, and / or use of the sensing element 128, external element(s) 150, and / or stimulation element 1 17 are described below in association with at least FIGS. 1 C-26.

[0039] In some examples, at least a portion of the stimulation element 1 17 may comprise part of an external component / device such as, but not limited to, the external component comprising a pulse generator (e.g., stimulation / control circuitry), power supply (e.g., rechargeable, non-rechargeable), and / other components. In some examples, a portion of the stimulation element 1 17 may be implantable and a portion of the stimulation element 1 17 may be external to the patient.

[0040] Accordingly, as further shown in FIG. 1 B, the various sensing element(s) 128 and / or stimulation element(s) 117 implanted in the patient’s body may be in wireless communication (e.g., connection 137) with at least one external element 150.

[0041] As further shown in FIG. 1 B, in some examples, the external element(s) 150 may be implemented via a wide variety of formats such as, but not limited to, at least one of the formats 151 including a patient support 152 (e.g., bed, chair, sleep mat, other), wearable elements 154 (e.g., finger, wrist, head, neck, shirt), noncontact elements 156 (e.g., watch, camera, mobile device, other), and / or other elements 158.

[0042] As further shown in FIG. 1 B, in some examples, the external element(s) 150 may comprise one or more different modalities 170 such as (but not limited to) a sensing portion 171 , stimulation portion 172, power portion 174, communication portion 176, and / or other portion 178. The different portions 171 , 172, 174, 176, 178 may be combined into a single physical structure (e.g., package, arrangement, assembly), may be implemented in multiple different physical structures, and / or with just some of the different portions 171 , 172, 174, 176, 178 combined together in a single physical structure.

[0043] In some examples, the external stimulation portion 172 and / or implantable portions of stimulation element 117 may comprise at least some ofsubstantially the same features and attributes of at least the stimulation arrangements, as further described below in association with at least FIGS. 2A- 26 and / or other examples throughout the present disclosure.

[0044] In some examples, the external power portion 174 and / or power components associated with stimulation element 117 (e.g., implantable portions) may comprise at least some of substantially the same features and attributes of at least the stimulation arrangements, as further described throughout the examples of the present disclosure. In some such examples, the respective power portion, components, etc. may comprise a rechargeable power element (e.g., supply, battery, circuitry elements) and / or non-rechargeable power elements (e.g., battery). In some examples, the external power portion 174 may comprise a power source by which a power component of the stimulation element 117 (e.g., implantable portions) may be recharged.

[0045] In some examples, the wireless communication portion 176 (e.g., connection / link at 137) may be implemented via various forms of radiofrequency communication and / or other forms of wireless communication, such as (but not limited to) magnetic induction telemetry, Bluetooth (BT), Bluetooth Low Energy (BLE), near infrared (NIF), near-field protocols, Wi-Fi, Ultra-Wideband (UWB), ultrasonic waves, and / or other short range or long range wireless communication protocols suitable for use in communicating between implanted components and external components in a medical device environment.

[0046] Examples are not so limited as expressed by other portion 178 via which other aspects of implementing medical care may be embodied in external element(s) 150 to relate to the various implanted and / or external components described above.

[0047] FIG. 1 C schematically represents a control portion 190, which may comprise at least some of substantially the same features and attributes as the control portion 2200 in FIG. 24A. The control portion 190 may be used to implement at least some of the various example devices and / or example methods of the present disclosure as described herein. In some examples, the control portion 190 may form part of, and / or be in communication with, the sensingelement 128 and / or the stimulation element 117 in FIG. 1 B, external element(s) 150, and / or other medical device (or portions thereof), as further described later.

[0048] FIG. 2A is a block diagram schematically representing an example system 200a including an implantable medical device (IMD) 202a and an external charger 220a. In some examples, the IMD 202a may be implanted into a patient for diagnostic, therapeutic, drug delivery, and / or other suitable purposes. In some examples, the IMD 202a may be used to apply electrical stimulation to respiratory-related tissue, such as (but not limited to) an upper airway patency- related tissue of a patient, to treat sleep disordered breathing (SDB) conditions. In some examples, the IMD 202a may be used to apply electrical stimulation to other tissues (e.g., pelvic, spinal) of a patient to treat other conditions (e.g., urinary and / or fecal incontinence).

[0049] The IMD 202a includes a power element 204 and a wireless receiver 206. The external charger 220a includes a wireless transmitter 222 to transmit power to the wireless receiver 206 of the IMD 202a over a wireless path 223. The wireless receiver 206 receives power transmitted from the wireless transmitter 222 to charge (or recharge) the power element 204. In some examples, the wireless receiver 206 also receives communications from the external charger 220a over the wireless path 223. The wireless transmitter 222 may separately transmit power and communication signals to the wireless receiver 206 at different times or may combine (e.g., multiplex) power and communication signals such that power and communications are transmitted simultaneously. The power element 204 may be a liquid electrolyte battery (e.g., lithium-ion battery), a solid- state battery, a supercapacitor, or other suitable component configured to store energy that may be used to power the IMD 202a. In some examples, the solid- state battery may comprise a thin-film solid-state electrolyte, such as (but not limited to) a lithium phosphorus oxynitride (LiPON) material.

[0050] The time required to recharge the power element 204 of the IMD 202a is based upon the power element technology. For example, given a supercapacitor, a solid-state battery, and a liquid electrolyte battery each having the same energy capacity, in some examples the supercapacitor may be recharged from a 10 percent charge to a 90 percent charge faster than the solid-state battery, and thesolid-state battery may be recharged from a 10 percent charge to a 90 percent charge faster than the liquid electrolyte battery. For example, when a supercapacitor is used as the power element 204, the IMD 202a may be rapidly recharged from a 10 percent charge to a 90 percent charge by the external charger 220a in under 90 seconds for example. When a solid-state battery is used as the power element 204, the IMD 202a may be quickly recharged from a 10 percent charge to a 90 percent charge by the external charger 220a in under 10 minutes for example. When a liquid electrolyte battery is used as the power element 204, the IMD 202a may be recharged from a 10 percent charge to a 90 percent charge by the external charger 220a in 20 to 30 minutes for example.

[0051] In examples in which a solid-state battery is used as the power element 204, the power element 204 and thus the IMD 202a may be made smaller since solid state batteries are more energy dense than supercapacitors and liquid electrolyte batteries. Supercapacitors and solid-state batteries are safer than liquid electrolyte batteries, since there is little risk of a liquid electrolyte leaking and the risk of fire may be reduced. Supercapacitors can withstand more charge and discharge cycles (e.g., hundreds of thousands) than solid state batteries before degrading (e.g., storing less energy), and solid-state batteries can withstand more charge and discharge cycles (e.g., about 5000) than liquid electrolyte batteries (e.g., about 1000) before degrading. Supercapacitors have an additional benefit over both solid-state batteries and liquid electrolyte batteries in that supercapacitors do not contain any toxic metals (e.g., lithium) that may involve more special handling, sealing, etc. to permit use within a patient. In some examples, the power element 204 may include two or more power storage technologies, such as a supercapacitor paired with a solid-state battery.

[0052] In some examples, the wireless transmitter 222 transmits power (and / or communications) to the wireless receiver 206 using inductive coupling or nearfield radio frequency (RF) wireless power transfer.

[0053] FIG. 2B is a block diagram schematically representing an example system 200b including an implantable medical device (IMD) 202b and an external charger 220b. The IMD 202b is similar to the IMD 202a of FIG. 2A, except that the IMD 202b further includes a wireless transmitter 208. The wireless transmitter208 may operate at the same frequency as the wireless receiver 206 or at a different frequency from the wireless receiver 206. In some examples, the wireless receiver 206 and the wireless transmitter 208 may be combined into a wireless transceiver. The external charger 220b is similar to the external charger 220a of FIG. 2A, except that the external charger 220b further includes a wireless receiver 224. The wireless receiver 224 may operate at the same frequency as the wireless transmitter 222 or at a different frequency from the wireless transmitter 222. In some examples, the wireless transmitter 222 and the wireless receiver 224 may be combined into a wireless transceiver.

[0054] The wireless transmitter 208 of the IMD 202b may transmit communications and / or other signals to the wireless receiver 224 of the external charger 220b through a wireless communication path 209. In some examples, the IMD 202b may transmit communications and / or other signals to the external charger 220b simultaneously with receiving power from the external charger 220b for charging the power element 204. As further described below with reference to at least FIGS. 28A-30, the communications and / or other signals transmitted to the external charger 220b from the IMD 202b may be used to configure the wireless transmitter 222 to optimize the power transfer to the IMD 202b.

[0055] FIG. 2C is a block diagram schematically representing an example system 200c including an implantable medical device (IMD) 202c and an external charger 220c. The IMD 202c is similar to the IMD 202a of FIG. 2A, except that the IMD 202c further includes a Bluetooth Low Energy (BLE) transceiver 210. The BLE transceiver 210 may operate at a different frequency (e.g., 2.45 GHz) from the wireless receiver 206. The external charger 220c is similar to the external charger 220a of FIG. 2A, except that the external charger 220c further includes a BLE transceiver 226. The BLE transceiver 226 may operate at a different frequency from the wireless transmitter 222. The BLE transceiver 210 of the IMD 202c may exchange communications with the BLE transceiver 226 of the external charger 220c through a Bluetooth communication path 21 1 . In some examples, the IMD 202c may exchange communications with the external charger 220c simultaneously with receiving power from the external charger 220c for charging the power element 204. As further described below with referenceto at least FIGS. 10A-23, the communications exchanged between the IMD 202c and the external charger 220c may be used to configure the wireless transmitter 222 to optimize the power transfer to the IMD 202c.

[0056] Communications from an external charger (e.g., 220a-220c of FIGS. 2A- 2C) to an IMD (e.g., 202a-202c of FIGS. 2A-2C) may be defined as a downlink. Communications from an IMD to an external charger may be defined as an uplink. Communications that are at or near the recharge frequency may be defined as in-band communications. Communications that are outside of the recharge frequency may be defined as out-of-band communications. For in-band downlink and uplink, charging may be paused for communications and resumed once the communications are complete. For out-of-band downlink and uplink, charging and communications may occur simultaneously. For in-band downlink and out- of-band uplink, there are at least two options as follows: 1 ) pause charging during downlink; or 2) encode the charging energy for simultaneous charging and downlink. In either case, charging may continue during uplink.

[0057] Uplink may be performed using BLE (e.g., via BLE transceivers 210 and 226 of FIG. 2C). The external charger and the IMD may exchange security / encryption settings. This exchange may be performed once during pairing or each time a charging session begins. The external charger and the IMD may maintain an active BLE session or disconnect. If disconnected, the IMD may utilize advertisement or extended advertisement packets for uplink, without the need to stay connected to the external charger. Advertisement packets may be encrypted such that only the external charger and other paired devices can decrypt the uplink information.

[0058] FIG. 3A is a diagram schematically representing an example implantable medical device (IMD) 250a. In some examples, the IMD 250a may comprise at least some of substantially the same features as, and / or comprise an example implementation of at least some of the features of, the implantable components (e.g., 117, 128) in the arrangements of FIGS. 1 A-1 C and / or of IMDs 202a-202c of FIGS. 2A-2C.

[0059] As shown in FIG. 3A, in some examples, IMD 250a includes a housing 252, a wireless communication portion 253, and a stimulation element 256. Insome examples, the wireless communication portion 253 may comprise a wireless receiver 206 and / or a wireless communication element 260 (e.g., antenna). In some examples, the IMD 250a may be implanted into a patient for therapeutic and / or other suitable purposes. In some examples, via the stimulation element 256, the IMD 250a may be used to apply electrical stimulation to respiratory-related tissue, such as (but not limited to) an upper airway patency- related tissue of a patient, to treat sleep disordered breathing (SDB) conditions. In some examples, the IMD 250a may be used to apply electrical stimulation to other tissues (e.g., pelvic, spinal) of a patient to treat other conditions (e.g., urinary and / or fecal incontinence).

[0060] The wireless receiver 206 of the wireless communication portion 253 may receive power transmitted from an external power source or charger (e.g., 174 / 150 of FIG. 1 B, 220a-220c of FIGS. 2A-2C, 2370 of FIG. 26) to power the IMD 250a including the wireless receiver 206 and the stimulation element 256. In some examples, the wireless receiver 206 also receives communications from the external charger such as in association with communication portion 176 in FIG. 1 B. In some examples, the wireless receiver 206 receives power (and / or communications) using inductive coupling or near-field radio frequency (RF) wireless power transfer.

[0061] The wireless communication element 260 of the wireless communication portion 253 may include a coil antenna for inductive or near-field RF wireless power transfer (e.g., for frequencies less than or equal to about 50 MHz). In the IMD 250a, the wireless communication element 260 may be arranged on the housing 252 (e.g., on an exterior wall of the housing 252 or on an interior wall of the housing 252) or integrated within (e.g., embedded within, etched into) the housing 252. The wireless communication element 260 is electrically coupled to the wireless receiver 206 and is configured to receive power from a wireless transmitter (e.g., 174 in FIG. 1 B, 222 of FIGS. 2A-2C, 2370 of FIG. 26) to power the wireless receiver 206 and the stimulation element 256. In some examples, the wireless communication element 260 may also receive communication signals and / or control signals from an external charger (e.g., 176 in FIG. 1 B, 220a-220c of FIGS. 2A-2C, 2370 of FIG. 26) or other device (e.g., a mobile device2320, a remote control 2340, a clinician programmer 2350, and / or a patient management tool 2360 of FIG. 26).

[0062] The stimulation element 256 may include stimulation circuitry and / or at least one stimulation electrode to apply electrical stimulation to a patient. The stimulation element 256 receives power and / or control signals from the wireless receiver 206 of wireless communication portion 253. The electrical stimulation may be applied via at least one electrode of the stimulation element 256 or electrically coupled to the stimulation element 256. In some examples, at least one electrode (not shown) may be arranged on the housing 252 or on a lead electrically coupled to the stimulation element 256.

[0063] In some examples, the housing 252 encloses at least a portion of the wireless communication portion 253 (e.g., the wireless receiver 206) and at least a portion (e.g., at least stimulation circuitry) of the stimulation element 256. In some examples, housing 252 may encapsulate (e.g., overmold) the wireless receiver 206 and the stimulation element 256 to hermetically seal at least a portion (e.g., the wireless receiver 206) of the wireless communication portion 253 and at least a portion (e.g., stimulation circuitry) of the stimulation element 256. Housing 252 may include any suitable biocompatible material, such as a metal (e.g., titanium, stainless steel, MP35N), a thermoplastic polymer (e.g., silicone), a thermoset material, a blend polymer material (e.g., polyetheretherketone (PEEK)), a ceramic material (e.g., glass), or a combination thereof. Different portions of the housing 252 may be made of different materials. For example, a first portion of the housing 252 may be made of a metal (e.g., titanium) while a second portion of the housing where the wireless communication element 260 is arranged may be made of a nonconductive material (e.g., PEEK).

[0064] In some examples, the IMD 250a may be implanted in the torso 120 or pelvic region 129. In some such examples, the IMD 250a may be sized and shaped to be implanted within a head 112 or a neck 114 (or head-and-neck portion 110) while also sometimes being referred to as a microstimulator or as a pulse generator sized and shaped for implantation in the head 112 or neck 1 14 (or head-and-neck portion 1 10). The microstimulator may include the housing 252 to encapsulate (e.g., hermetically seal) at least a portion (e.g., wirelessreceiver 206) of the wireless communication portion 253 and at least a portion (e.g., stimulation circuitry) of the stimulation element 256.

[0065] FIG. 3B is a diagram schematically representing an example IMD 250b. In some examples, the IMD 250b may comprise at least some of substantially the same features and attributes as IMD 250a of FIG. 3A. As shown in FIG. 3B, the IMD 250b may include a power element 204 and a wireless receiver 206 for charging the power element 204 as previously described. In addition, the IMD 250b may include a housing 252, a control portion 254, and a wireless communication element 260 (e.g., antenna). Housing 252 encloses the power element 204, the wireless receiver 206, and the control portion 254. In some examples, housing 252 may encapsulate (e.g., overmold) the power element 204, the wireless receiver 206, and the control portion 254 to hermetically seal the power element 204, the wireless receiver 206, and the control portion 254 within the housing 252.

[0066] The control portion 254 may control the wireless receiver 206, the power element 204, and other circuitry (not shown) of the IMD 250b. In some examples, the control portion 254 may implement aspects of the example methods described below with reference to at least FIGS. 10A-23. The control portion 254 may include a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), and / or other suitable logic circuitry. At least some example implementations of the control portion 254 are further described below with reference to at least FIGS. 24A and 24B.

[0067] It will be further understood that in some examples, at least some aspects or elements of the control portion 254 may form part of, and / or be distributed among, the other components (e.g., power, wireless communication portion 253, other) of the IMD 250b such that control portion 254 does not necessarily form a component of the IMD 250b separate from those other elements (e.g., power, wireless communication, etc.).

[0068] In some examples, an IMD 250b may comprise a power source for other IMDs in close enough proximity to be in power-exchanging relation to the IMD 250b such that IMD 250b may omit a sensing element, stimulation element, etc. and solely serve as a power resource within the patient’s body to support otherIMDs within the patient’s body. In some such examples, such support to help power other IMDs within the patient may comprise the IMD 250b including a wired connection to such other IMDs, such as via a lead or other means.

[0069] Similarly, in some examples, with or without its own power element (and / or with or without elements for sensing, stimulation etc.), an IMD may provide a wireless communication node to support wireless communication with other IMDs within a patient’s body and / or wireless communication with external elements (e.g., 150 in FIG. 1 B), which may support such IMDs acting as intrabody wireless communication nodes.

[0070] FIG. 3C is a diagram schematically representing an example IMD 250c. The IMD 250c is similar to the IMD 250b of FIG. 3B, except that the IMD 250c further includes stimulation element 256. In this example, the control portion 254 may include a therapy manager arranged to control the stimulation element 256 based on at least control information to apply electrical stimulation to a patient. In some examples, the therapy manager may be arranged to control (e.g., based on control information) the stimulation element 256 to apply electrical stimulation to respiratory-related tissue (e.g., upper airway patency-related tissue) to treat sleep disordered breathing (SBD) conditions or to apply electrical stimulation to other tissues, as noted above. The electrical stimulation may be applied via at least one electrode electrically coupled to the stimulation element 256. In some examples, at least one electrode (not shown) may be arranged on the housing 252 or on a lead electrically coupled to the stimulation element 256.

[0071] In some examples, the IMD 250c may be implanted in the torso 120 or pelvic region 129. In some such examples, the IMD 250c may be sized and shaped to be implanted within a head 112 or a neck 114 (or head-and-neck portion 110) while also sometimes being referred to as a microstimulator or as a pulse generator sized and shaped for implantation in the head 112 or neck 1 14 (or head-and-neck portion 1 10). The microstimulator may include the housing 252 to encapsulate (e.g., hermetically seal) at least the power element 204, the wireless communication portion 253 (e.g., wireless receiver 206 and / or wireless communication element 260), the stimulation element 256, and / or the control portion 254.

[0072] FIG. 3D is a diagram schematically representing an example IMD 250d. The IMD 250d is similar to the IMD 250b of FIG. 3B, except that the IMD 250d further includes a sensing element 258 and the wireless communication element 260 is integrated into or on the power element 204. In some examples, the wireless communication element 260 may be wrapped around the power element 204 or arranged on a casing of the power element 204. Alternatively, as previously described above with reference to FIG. 3A, the wireless communication element 260 may be arranged on the housing 252 or integrated within the housing 252.

[0073] In this example, the control portion 254 may include a sensing manager arranged to control the sensing element 258 based on at least control information to obtain sensing information (e.g., physiologic information) for a patient. The sensing element 258 may include at least one sensor (e.g., accelerometer, gyroscope, piezoelectric sensor, microphone, temperature sensor, pressure sensor, etc.) and / or other suitable circuitry for obtaining sensing information for a patient. The sensing information (e.g., sensed physiologic information) may include respiratory information, cardiac information, activity information, motion information, posture information, and / or other information about the patient. In some examples, the sensing element 258 of the IMD 250d may be included along with the stimulation element 256 of the IMD 250c within a single IMD. The sensing element 258 may sense sensing information of a patient via at least one electrode electrically coupled to the sensing element 258. In some examples, at least one electrode (not shown) may be arranged on the housing 252 or on a lead electrically coupled to the sensing element 258. In some examples in which a sensing element comprises at least one electrode, the at least one electrode also may, at times, be used for stimulation and / or comprise a portion of the stimulation element 256.

[0074] The sensed information may be used to initiate, terminate, pause, synchronize, and / or trigger therapy to be applied via an IMD and / or external therapy elements. In some examples, the sensed information may be used as feedback for controlling therapy (e.g., stimulation therapy), such as closed loop therapy. The sensed information also may be used for diagnostic purposesand / or for monitoring (and / or evaluation of) a particular physiologic effect, physiologic response, etc. regardless of whether the sensed information is used for other purposes (e.g., therapy). In some such examples, the sensed information may be used to evaluate open loop therapy (e.g., stimulation) which does not include a feedback loop to initiate, terminate, pause, synchronize, and / or trigger delivery of therapy.

[0075] In some examples, an IMD may comprise any one of various combinations of the above-described elements (e.g., stimulation, sensing, power, communication, control) of the respective IMDs described in association with FIGS. 2A-3D and / or FIGS. 1A-1 C. In one example, a sensing element (e.g., 258 in FIG. 3D) may take the place of the stimulation element 256 of the IMD 250a in FIG. 3A, or vice versa. In another example, both the sensing and stimulation elements 258, 256 may be included in the same IMD or all three of the sensing, stimulation, and power elements 258, 256, 204 may be included in the same IMD, along with other elements such as a wireless communication portion 253 and / or control portion 254. At least some of these various combinations regarding FIGS. 1 A-3D are also applicable to the various later described examples associated with FIGS. 4-26.

[0076] While devices 250a-250d of FIGS. 3A-3D were described as implantable medical devices, in some examples, devices 250a-250d may be injectable medical devices or insertable medical devices. In some examples, devices 250a- 250d may include a wearable medical device or a wearable consumer device. For example, devices 250a-250d may include a medical device, a diagnostic device, a hearing aid, or a wireless earbud. In some examples, the charger and methods disclosed herein with reference to at least FIGS. 4-23 may be applicable to wirelessly transmitting power to any suitable device to either power the device or to recharge a power element of the device.

[0077] FIG. 4 is a diagram schematically representing an example antenna 300 including three orthogonal coils 302a, 302b, and 302c that may be configured to receive wireless power. In some examples, antenna 300 may provide wireless communication element 260 of wireless communication portion 253 of FIGS. 3A- 3D. The coils 302a, 302b, and 302c may be wrapped around a power element(e.g., 204 of FIGS. 2A-3D) or a magnetic core (e.g., ferrite core) along orthogonal axes. The coils 302a, 302b, and 302c may include a single coil element (e.g., wire) with windings across the three axes, or each coil 302a, 302b, and 302c may be separate from each other (e.g., separate windings). The antenna 300 may be part of a wireless receiver (e.g., 206 of FIGS. 2A-3D) of an IMD (e.g., 200a-200c of FIGS. 2A-2C or 250a-250d of FIGS. 3A-3D). By including orthogonal coils 302a, 302b, and 302c within an IMD, an external charger (e.g., 174 / 176 of FIG. 1 B, 220a-220c of FIGS. 2A-2C, 2370 of FIG. 26) may maintain sufficient coupling (e.g., inductive or near-field RF) with the antenna 300 independent of the orientation of the IMD due to the position and / or posture of the patient relative to the external charger. In addition, for the transmit coil(s) of an external charger that do not have field diversity in different orthogonal axes, antenna 300 provides increased receiver diversity to improve coupling for various patient positions / postures. While coils 302a, 302b, and 302c are illustrated as having a rectangular arrangement in FIG. 4, in some examples, coils 302a, 302b, and 302c may have another suitable geometric arrangement, such as circular, elliptical, triangular, hexagonal, etc., or a non-geometric or asymmetrical arrangement.

[0078] FIG. 5 is a cross-sectional view schematically representing an example antenna 310 including a coil 312 arranged around a power element 204 that may be configured to receive wireless power. In some examples, antenna 310 may provide wireless communication element 260 of wireless communication portion 253 of FIGS. 3A-3D. While FIG. 5 illustrates one coil 312, antenna 310 may include one or two additional orthogonal coils (e.g., see FIG. 4). While the power element 204 is illustrated as having an elliptical cross-sectional shape in FIG. 5, in some examples, the power element 204 may have another suitable cross- sectional shape, such as rectangular, circular, triangular, hexagonal, etc., or a non-geometric or asymmetric shape. Thus, the coil 312 may conform to the shape of the power element 204. The shape of the power element 204, and thus the shape of the coil 312, may be selected to conform to a shape of a housing (e.g., 252 of FIGS. 3B-3D) enclosing the power element. The shape of the housing may be selected based on where the IMD is intended to be implantedwithin a patient. In some examples, a wireless receiver (e.g., 206 of FIGS. 2A- 3D) may include a capacitor to tune the antenna 310.

[0079] FIG. 6 is a cross-sectional view schematically representing an example antenna 320 including a coil 322 arranged around an interior of a housing 252 that may be configured to receive wireless power. In some examples, antenna 320 may provide wireless communication element 260 of wireless communication portion 253 of FIGS. 3A-3D. In some examples, the coil 322 may be applied (e.g., glued, formed, printed) on an interior wall of the housing 252 or etched into the interior wall of the housing 252. While FIG. 6 illustrates one coil 322, the antenna 320 may include one or two additional orthogonal coils (e.g., see FIG. 4). While the housing 252 is illustrated as having an elliptical cross-sectional shape in FIG. 6, in some examples, the housing 252 may have another suitable cross-sectional shape, such as rectangular, circular, triangular, hexagonal, etc., or a nongeometric or asymmetric shape. The shape of the housing 252 may be selected based on where the IMD is intended to be implanted within a patient. The coil 322 may conform to the shape of the housing 252. In some examples, a wireless receiver (e.g., 206 of FIGS. 2A-3D) may include a capacitor to tune the antenna 320.

[0080] FIG. 7A is a top view schematically representing an example array 500 of coils 502i to 502s, which may be part of an external charger (e.g., 220a-220c of FIGS. 2A-2C) to wirelessly transfer power to a device (e.g., IMD), such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9. Array 500 includes a first coil 502i, a second coil 5022 partially overlapping the first coil 502i, and a third coil 502s partially overlapping the first coil 502i and partially overlapping the second coil 5022. Thus, array 500 has an overall triangular shape. By overlapping the coils, inductive coupling between adjacent coils 502i to 5023 may be minimized. The array 500 of coils 502i to 5023 (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 502i to 502s or at least a subset of the coils 502i to 502s are aligned with the IMD (e.g., 706 of FIG. 9) to inductively or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD despite thelocation, orientation, and / or posture of the patient (e.g., 704 of FIG. 9), and thus the IMD, relative to the array 500 of coils 502i to 502s.

[0081] FIG. 7B is a top view schematically representing an example array 510 of coils 512i to 5124, which may be part of an external charger (e.g., 220a-220c of FIGS. 2A-2C) to wirelessly transfer power to a device (e.g., IMD), such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9. Array 510 includes a first coil 512i , a second coil 5122 partially overlapping the first coil 512i , a third coil 512s partially overlapping the second coil 5122, and a fourth coil 5124 and partially overlapping the third coil 512a and partially overlapping the first coil 512i. Thus, array 510 has an overall square shape. By overlapping the coils, inductive coupling between adjacent coils 512i to 5124 may be minimized. The array 510 of coils 512i to 5124 (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 512i to 5124 or at least a subset of the coils 512i to 5124 are aligned with the IMD (e.g., 706 of FIG. 9) to inductively or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD despite the location, orientation, and / or posture of the patient (e.g., 704 of FIG. 9), and thus the IMD, relative to the array 510 of coils 512i to 5124.

[0082] FIG. 7C is a top view schematically representing an example array 520 of coils 522i to 5224, which may be part of an external charger (e.g., 220a-220c of FIGS. 2A-2C) to wirelessly transfer power to a device (e.g., IMD), such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9. Array 520 includes a first coil 522i ; a second coil 5222 partially overlapping the first coil 522i ; a third coil 522s partially overlapping the second coil 5222; and a fourth coil 5224 partially overlapping the third coil 522s, partially overlapping the second coil 5222, and partially overlapping the first coil 522i. Thus, array 520 has an overall rhombus shape. By overlapping the coils, inductive coupling between adjacent coils 522i to 5224 may be minimized. The array 520 of coils 522i to 5224 (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 522i to 5224 or at least a subset of the coils 522i to 5224 are aligned with the IMD (e.g., 706 of FIG. 9) toinductively or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD despite the location, orientation, and / or posture of the patient (e.g., 704 of FIG. 9), and thus the IMD, relative to the array 520 of coils 522i to 5224.

[0083] FIG. 7D is a top view schematically representing an example array 530 of coils 532i to 5325, which may be part of an external charger (e.g., 220a-220c of FIGS. 2A-2C) to wirelessly transfer power to a device (e.g., IMD), such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9. Array 530 includes a first coil 532i ; a second coil 5322 partially overlapping the first coil 532i ; a third coil 532s partially overlapping the second coil 5322; a fourth coil 5324 partially overlapping the third coil 532s, partially overlapping the second coil 5322, and partially overlapping the first coil 532i ; and a fifth coil 532s partially overlapping the fourth coil 5324 and partially overlapping the first coil 532i . Thus, array 530 has an overall trapezoidal shape. By overlapping the coils, inductive coupling between adjacent coils 532i to 532s may be minimized. The array 530 of coils 532i to 5325 (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 532i to 532s or at least a subset of the coils 532i to 532s are aligned with the IMD (e.g., 706 of FIG. 9) to inductively or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD despite the location, orientation, and / or posture of the patient (e.g., 704 of FIG. 9), and thus the IMD, relative to the array 530 of coils 532i to 5325.

[0084] FIG. 7E is a top view schematically representing an example array 540 of coils 542i to 5426, which may be part of an external charger (e.g., 220a-220c of FIGS. 2A-2C) to wirelessly transfer power to a device (e.g., IMD), such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9. Array 540 includes a first coil 542i ; a second coil 5422 partially overlapping the first coil 542i ; a third coil 5423 partially overlapping the second coil 5422 and partially overlapping the first coil 542i ; a fourth coil 5424 partially overlapping the third coil 542s; a fifth coil 542s partially overlapping the fourth coil 5424, partially overlapping the third coil 542s, and partially overlapping the second coil 5422; anda sixth coil 542e partially overlapping the fifth coil 542s and partially overlapping the second coil 5422. Thus, array 540 has an overall triangular shape. By overlapping the coils, inductive coupling between adjacent coils 542i to 5426 may be minimized. The array 540 of coils 542i to 542e (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 542i to 5426 or at least a subset of the coils 542i to 5426 are aligned with the IMD (e.g., 706 of FIG. 9) to inductively or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD despite the location, orientation, and / or posture of the patient (e.g., 704 of FIG. 9), and thus the IMD, relative to the array 540 of coils 542i to 5426.

[0085] FIG. 7F is a top view schematically representing an example array 550 of coils 552i to 552s, which may be part of an external charger (e.g., 220a-220c of FIGS. 2A-2C) to wirelessly transfer power to a device (e.g., IMD), such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9. In this example, array 550 includes a first coil 552i; a second coil 5522 partially overlapping the first coil 552i ; a third coil 552a partially overlapping the second coil 5522; a fourth coil 5524 partially overlapping the third coil 552s and partially overlapping the second coil 5522; a fifth coil 5525 partially overlapping the fourth coil 5524, partially overlapping the second coil 5522, and partially overlapping the first coil 552i ; a sixth coil 5526 partially overlapping the fifth coil 552s; a seventh coil 552? partially overlapping the sixth coil 552e, partially overlapping the fifth coil 5525, and partially overlapping the fourth coil 5524; and an eighth coil 552s partially overlapping the seventh coil 552? and partially overlapping the fourth coil 5524. Thus, array 550 has an overall rectangular shape. By overlapping the coils, inductive coupling between adjacent coils 552i to 552s may be minimized. The array 550 of coils 552i to 552s (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 552i to 552s or at least a subset of the coils 552i to 552s are aligned with the IMD (e.g., 706 of FIG. 9) to inductively or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD despite the location, orientation, and / or postureof the patient (e.g., 704 of FIG. 9), and thus the IMD, relative to the array 550 of coils 552i to 552s.

[0086] While FIGS. 7A-7F illustrate example arrays of coils including various numbers of coils in various configurations and having various overall shapes, in some examples, an array of coils of a charger may include another suitable number of coils (e.g., 2, 7, 9, 10 or more) in another suitable configuration (e.g., no overlapping coils, partially overlapping coils) and having another suitable overall shape (e.g., circular, hexagonal, octagonal, non-geometric, asymmetrical, etc.).

[0087] FIG. 8A is a top view schematically representing an example coil structure 560. Coil structure 560 is a rectangular (e.g., square shaped) spiral coil, which in some examples may provide each coil 502i to 502s of FIG. 7A, 512i to 512 of FIG. 7B, 522i to 522 of FIG. 7C, 532i to 5325of FIG. 7D, 542i to 5426of FIG. 7E, or 552i to 552s of FIG. 7F. In some examples, the size of the coil structure 560 within an external charger (e.g., 220a-220c of FIGS. 2A-2C) used to transmit power to a coil structure of an IMD (e.g., 202a-202c of FIGS. 2A-2C or 250a-250d of FIGS. 3A-3D) may be selected based on the size of the IMD. For optimum power transmission, the size (e.g., length, width) of the coil structure 560 within the external charger should be within a range between about 50% to 500% of the distance between the coil structure of the external charger and the coil structure (e.g., 300 of FIG. 4, 310 of FIG. 5, or 320 of FIG. 6) of the IMD.

[0088] FIG. 8B is a top view schematically representing an example coil structure 570. Coil structure 570 is a circular spiral coil, which in some examples may provide each coil 502i to 502s of FIG. 7A, 512i to 5124of FIG. 7B, 522i to 5224of FIG. 7C, 532i to 5325of FIG. 7D, 542i to 5426of FIG. 7E, or 552i to 5528of FIG. 7F. In some examples, the size of the coil structure 570 within an external charger (e.g., 220a-220c of FIGS. 2A-2C) used to transmit power to a coil structure of an IMD (e.g., 202a-202c of FIGS. 2A-2C or 250a-250d of FIGS. SA- SD) may be selected based on the size of the IMD. For optimum power transmission, the size (e.g., diameter) of the coil structure 570 within the external charger should be within a range between about 50% to 500% of the distancebetween the coil structure of the external charger and the coil structure (e.g., 300 of FIG. 4, 310 of FIG. 5, or 320 of FIG. 6) of the IMD.

[0089] While coil structure 560 of FIG. 8A has a square shape and coil structure 570 of FIG. 8B has a circular shape, in some examples, the coil structures may have another suitable shape, such as triangular, hexagonal, octagonal, etc. In some examples, coil structure 560 of FIG. 8A, coil structure 570 of FIG. 8B, and / or arrays 500, 510, 520, 530, 540, and 550 of FIG. 7A-7E may be formed via traces on and / or within a printed circuit board (PCB) or another substrate.

[0090] FIG. 9 is a top view schematically representing an example coil arrangement 700 of an external charger (e.g., 220a-220c of FIGS. 2A-2C). A patient 704 including an IMD 706 may lie on a bed 702 or other support to charge or power the IMD 706. While the IMD 706 is illustrated in FIG. 9 as being implanted in a head-and-neck region of the patient 704, in some examples, the IMD 706 may be implanted in another region (e.g., torso, pelvis) of the patient. In some examples, the IMD 706 may be similar to an IMD 250a-250d of FIGS. 3A- 3D. In this example, the external charger includes an array 710 of coils 712 for wirelessly charging the IMD 706 via inductive wireless power transfer or nearfield RF wireless power transfer. In some examples, the array 710 of coils 712 may be integrated into the bed 702, a mattress, bedding, a pillow, a pad, etc. In some examples, the array 710 of coils 712 may be integrated into clothing (e.g., shirt, sash, belt, etc.) or a device (e.g., collar, band, etc.) that the patient can wear. In some examples, the array 710 of coils 712 may be integrated into a device configured to be worn around a patient’s neck.

[0091] In the example of FIG. 9, the coils 712 are arranged adjacent to each other and partially overlap. In some examples, each coil 712 may be a coil structure 560 or 570 of FIGS. 8A and 8B. The array 710 of coils 712 (or coil structures) may be sufficiently large (e.g., proximate at least the head, neck, and / or torso of the patient), such that at least one coil 712 or at least a subset of the coils 712 are aligned with the IMD 706 to inductively couple (for inductive wireless power transfer) or RF couple (for near-field RF wireless power transfer) to an antenna (e.g., 260 of FIGS. 3A-3D, 300 of FIG. 4, 310 of FIG. 5, 320 of FIG. 6) of the IMD 706 despite the location, orientation, and / or posture of the patient704, and thus the IMD 706, relative to the array 710 of coils 712. By using coil arrangement 700, in some examples, the external charger may activate only the coil(s) 712 closest to the IMD 706 to power and / or charge the IMD, thereby using less power and exposing the patient 704 to less electromagnetic radiation.

[0092] In some examples, the array 500, 510, 520, 530, 540, or 550 previously described and illustrated with reference to FIGS. 7A-7F may be used in place of the array 710 of FIG. 9 to wirelessly transmit power to the IMD 706. In some examples, as described below with reference to FIGS. 10A-23, a coil weighting for each coil (e.g., an amplitude and phase to be applied to each coil) of the array of coils may be determined to optimize (e.g., maximize) wireless power transfer to the IMD 706.

[0093] FIGS. 10A-10E are flow diagrams schematically representing example methods 1000a-1 OOOe for configuring a charger for wirelessly transmitting power to a device (e.g., an IMD such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9) from the charger (e.g., 220a-220c of FIGS. 2A-2C or 2370 of FIG. 26). In some examples, methods 1000a-1000e may be implemented by a control portion (e.g., 190 of FIG. 1 C, 2200 of FIGS. 24A and 24B) of the charger and / or the device.

[0094] As illustrated in FIG. 10A at 1002, method 1000a includes determining an amplitude and phase (e.g., weighting) for each coil (e.g., 502i to 502s of FIG. 7A, 512i to 5124 of FIG. 7B, 522i to 5224of FIG. 7C, 532i to 5325of FIG. 7D, 542i to 5426of FIG. 7E, 552i to 5528of FIG. 7F, or 712 of FIG. 9) of the array of coils (e.g., 500 of FIG. 7A, 510 of FIG. 7B, 520 of FIG. 7C, 530 of FIG. 7D, 540 of FIG. 7E, 550 of FIG. 7F, or 710 of FIG. 9) of the charger. The amplitude and phase for each coil of the array of coils of the charger may be determined to optimize (e.g., maximize) wireless power transfer from the array of coils to the device. In some examples, the amplitude and phase for each coil of the array of coils may be determined to maximize power transfer from the charger to the device while not exceeding safety limits (e.g., a Specific Absorption Rate (SAR) limit for the patient). The amplitude and phase for each coil of the array of coils may vary based on the location and orientation of the device with respect to the charger. Thus, in some examples, the amplitude and phase for each coil of thearray of coils may be periodically updated, such as in response to movement of the device relative to the charger. For example, for an IMD within a patient, the patient’s posture may be monitored and in response to each change in posture, the amplitude and phase for each coil of the array of coils of the charger may be updated.

[0095] In some examples, power is transmitted to power the device (e.g., 250a of FIG. 3A) by applying the corresponding amplitude and phase (as previously determined) to each coil of the array of coils of the charger. In some examples, power is transmitted to charge a power element (e.g., 204 of FIGS. 2A-2C or 3B- 3D) of the device by applying the corresponding amplitude and phase (as previously determined) to each coil of the array of coils of the charger.

[0096] In some examples, method 1000a may further include method 1000b of FIG. 10B. As illustrated in FIG. 10B at 1004, method 1000b may further include determining (e.g., via a control portion) a relative location of the device with respect to the charger. At 1006, method 1000b may further include determining (e.g., via a control portion) a relative orientation of the device with respect to the charger. In some examples, the amplitude and phase for each coil of the array of coils may be based upon the relative location (e.g., distance, coordinates) of the device with respect to the charger and the relative orientation (e.g., orientation of the antenna) of the device with respect to the charger as further described below with reference to FIGS. 1 1 -13B. In some examples, the relative location and relative orientation of the device with respect to the charger may be monitored, and in response to a change in the relative location and / or relative orientation of the device with respect to the charger, the amplitude and phase for each coil of the array of coils of the charger may be updated.

[0097] In some examples, method 1000a may further include method 1000c of FIG. 10C. As illustrated in FIG. 10C at 1008, method 1000c may further include determining a location (e.g., distance, coordinates) of the device relative to the charger. At 1010, method 1000c may further include determining an amplitude and phase for each coil of the array of coils based on the location of the device relative to the charger. In some examples, the amplitude and phase for each coil of the array of coils may be determined without determining the relativeorientation of the device with respect to the charger and without knowing the magnetic field distribution of the array of coils as further described below with reference to FIGS. 14-23.

[0098] In some examples, the relative location of the device with respect to the charger may be determined based on at least one of a pressure sensor signal (e.g., a pressure sensor signal from bed 702 or array 710 of FIG. 9), a posture of a patient in which the device is implanted (e.g., based on an accelerometer sensor signal of the device), and / or a received signal strength indicator (RSSI) of a radio frequency (RF) signal emitting from the device (e.g., from wireless transmitter 208 of device 202b of FIG. 2B or from BLE transceiver 210 of device 202c of FIG. 2C).

[0099] In some examples, determining a relative orientation of the device with respect to the charger as indicated at 1006 in method 1000b of FIG. 10B may further include method 1000d of FIG. 10D. As illustrated in FIG. 10D at 1012, method 1000d may further include receiving, from the device, an orientation of the device with respect to gravity. In some examples, the orientation of the device with respect to gravity may be sensed by a sensor (e.g., accelerometer, gyroscope) of the device and transmitted from the device to the charger. At 1014, method 1000d may further include measuring, via the charger, an orientation of the charger with respect to gravity. In some examples, the orientation of the charger with respect to gravity may be sensed by a sensor (e.g., accelerometer, gyroscope) of the charger. At 1016, method 1000d may further include determining (e.g., via a control portion of the charger) the relative orientation of the device with respect to the charger based on the orientation of the device with respect to gravity and the orientation of the charger with respect to gravity.

[0100] In some examples, determining a relative location of the device with respect to the charger as indicated at 1004 in method 1000b of FIG. 10B may further include method 1000e of FIG. 10E. As illustrated in FIG. 10E at 1018, method 1000e may further include transmitting a plurality of calibration pulses to the device via the array of coils. At 1020, method 1000e may further include receiving, from the device, a measured electrical parameter coupled to (e.g., received by) the device in response to each calibration pulse of the plurality ofcalibration pulses. The electrical parameter measured by the device in response to each calibration pulse may include a power, a voltage, or a current. In some examples, the electrical parameter may be measured by a wireless receiver (e.g., 206 of FIGS. 2A-2C or 3A-3D) of the device. At 1022, method 10OOe may further include locating the device (e.g., via a control portion of the charger) relative to the charger based on a relative orientation of the device with respect to the charger (e.g., as determined by method 1000d of FIG. 10D), a magnetic field distribution of each coil of the array of coils (e.g., as determined by simulations of the array of coils), and the measured electrical parameter coupled to the device in response to each calibration pulse of the plurality of calibration pulses. Accordingly, the amplitude and phase (e.g., weighting) for each coil of the array of coils is determined based on the received electrical parameters, which are used to determine the location of the device relative to the charger as further described below with reference to FIGS. 11 -13B.

[0101] FIG. 1 1 is a flow diagram schematically representing an example method 1100 for configuring a charger (e.g., 220a-220c of FIGS. 2A-2C or 2370 of FIG. 26) for wirelessly transmitting power to a device (e.g., an IMD such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9). As indicated at 1102, the magnetic field distribution (HRC), which may be a five dimensional matrix (XYZN3), of each coil of the array of coils is known and provides an input to method 1 100, where XYZ are cartesian coordinates of each respective coil, N is the number of coils, and 3 is the X, Y, and Z (e.g., Hx, HY, and Hz) components of the magnetic field of each respective coil. The magnetic field distribution (HRC) of each coil of the array of coils may be determined during the design of the array of coils using magnetic field mapping and / or electromagnetic simulations.

[0102] As indicated at 1 104, the relative orientation of the device with respect to the charger (VIMD), which may, in some examples, be a vector of length three, may be determined by a sensor (e.g., accelerometer, gyroscope) of the device and provides another input to method 1 100. At 1106, method 1 100 includes calculating a magnetic field of each coil (HVEC) of the array of coils relative to the device based on the orientation of the device with respect to the charger (VIMD) and the magnetic field distribution of each coil (H C) of the array of coils. HVEC,which may be a 4 dimensional matrix (XYZN), can be calculated by taking the inner product of HRC and VIMD as follows:HVEC=HRC ' VIMD

[0103] At 1 110, method 1 100 includes transmitting calibration pulses (e.g., from a single coil of the array of coils and / or a subset of at least two coils of the array of coils) from the charger to determine an electrical parameter (PIMD), such as a power, current, or voltage, measured by the device for each calibration pulse. The measured electrical parameter is transmitted from the device to the charger, such that the charger receives the measured electrical parameter coupled to (e.g., received by) the device in response to each calibration pulse. As indicated at 1 108, each calibration pulse is based on calibration pulse weights (MCAL) for each pulse, which may be a two-dimensional matrix (N by M), constructed using calibration pulse weights, where M is the number of calibration pulses. Example calibration pulse weights are described further below with reference to the tables of FIGS. 12A-12E. P IMD, which may be a vector of length M, includes a list of electrical parameter values (e.g., power, current, or voltage) measured by the device for each calibration pulse.

[0104] At 1112, method 1 100 includes determining the magnetic field generated by each calibration pulse by calculating PRC, which may be a four dimensional matrix (XYZM), by taking the inner product of HVEC and MCAL as follows:PRC=HVEC■ MCAL

[0105] At 1 114, method 1100 includes determining the location of the device with respect to the charger based on the received electrical parameter coupled to the device in response to each calibration pulse by identifying the XYZ indices of PRC that have the closest match to PIMD to identify coordinates of the device with respect to the charger. It is noted that each XYZ index of the PRC matrix is a vector of length M, which is the same as the vector length of PI D. The best match may be determined by a variety of methods, such as minimum absolute error, minimum mean squared error, etc. The XYZ indices that minimize the error correspond to the cartesian coordinates of the device. In this way, the location of the device with respect to the charger is identified. When combined with the relative orientation of the device with respect to the charger from 1104, both therelative location and the relative orientation of the device with respect to the charger are now known.

[0106] At 1 116, method 1 100 includes extracting from HVEC calculated at 1 106 an N by 1 vector (HIMD) at the XYZ coordinates determined at 11 14 as follows:^IMD ~ HVECx,y, z) where (x, y, z) are the Cartesian coordinates of the device with respect to the charger.

[0107] At 1 118, method 1100 includes calculating charge coil weights (ARC)(e.g., the amplitude and phase for each coil of the array of coils) as the complex conjugate of the HIMD vector as follows:where S is an arbitrary scaler and RC (an N by 1 vector) is the complex weighting of the voltage output of each coil. The coil weights define the amplitude and phase to be applied to each coil of the array of coils based on the location of the device with respect to each coil of the array of coils to wirelessly transfer power to the device.

[0108] FIGS. 12A-12E are tables 1200, 1210, 1220, 1230, and 1240, respectively, illustrating examples of calibration pulses that may be transmitted to a device (e.g., an IMD such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9) for configuring a charger (e.g., 220a-220c of FIGS. 2A- 2C or 2370 of FIG. 26) for wirelessly transmitting power to the device. Each table of FIGS. 12A-12C defines an example set of calibration pulses for an array of coils comprising four channels (i.e., four coils or coil structures), such as array 510 of FIG. 7B or array 520 of FIG. 7C. Each table of FIGS. 12D and 12E defines an example set of calibration pulses for an array of coils comprising three channels (i.e., three coils or coil structures), such as array 500 of FIG. 7A. The example sets of calibration pulses may provide the calibration pulses transmitted at 1018 in method 1000e of FIG. 10E or define the calibration pulse weights (MCAL) at 1 108 for each transmitted calibration pulse at 11 10 in method 1 100 of FIG. 1 1 . While the tables of FIGS. 12A-12E include examples for three or four channels, the examples may be extended to any number of channels, such as 5,6, 7, 8, or more channels, such as for array 530 of FIG. 7D, array 540 of FIG. 7E, array 550 of FIG. 7F, or array 710 of FIG. 9.

[0109] Table 1200 of FIG. 12A includes a series of ten calibration pulses. During each calibration pulse, the phase of the signal applied to each channel (CH 1 to CH 4) is the same (e.g., 0 degrees) and the amplitude (e.g., voltage) of the signal applied to each channel is either a 0 (i.e. , no signal) or a 1 (or another value). In this example, each channel is individually sequentially pulsed with a same amplitude signal as indicated for pulses 1 to 4, and then each unique pair of channels is sequentially pulsed with the same amplitude signal as indicated for pulses 5 to 10. Accordingly, in this example, transmitting the plurality of calibration pulses may include successively pulsing (e.g., via a control portion) each coil of the array of coils and successively pulsing (e.g., via the control portion) each subset of two coils of the array of coils.

[0110] Table 1210 of FIG. 12B includes a series of ten calibration pulses. During each calibration pulse, the phase of the signal applied to each channel (CH 1 to CH 4) is the same (e.g., 0 degrees) and the amplitude (e.g., voltage) of the signal applied to each channel is either a 0 (i.e., no signal), a 1 (or another positive value), or a -1 (or another negative value). In this example, a unique pair of channels is sequentially pulsed with one channel of the pair having a positive amplitude signal (e.g., 1 ) and the other channel of the pair having a negative amplitude signal (e.g., -1 ) as indicated for pulses 1 to 4, and then a group of three channels is sequentially pulsed with one channel of the three channels having a positive or negative amplitude signal (e.g., 1 or -1 ) and the other two channels of the three channels having a negative or positive amplitude signal (e.g., -1 or 1 ) as indicated for pulses 5 to 10. Accordingly, in this example, transmitting the plurality of calibration pulses may include successively pulsing (e.g., via a control portion) subsets of at least two coils of the array of coils comprising a first amplitude for a first coil of the at least two coils and a second amplitude for a second coil of the at least two coils.

[0111] Table 1220 of FIG. 12C includes a series of 1 1 calibration pulses. During each pulse, the phase and / or amplitude of the signal applied to each channel (CH 1 to CH 4) varies. In this example, the signal applied to each channel includes asame amplitude (e.g., 1 ) and a different phase (e.g., 0°, 45°, 90°, 135°, 180°, or 270°) as indicated for pulses 1 to 4; the signal applied to each channel includes the same amplitude (e.g., 1 ) and phase (e.g., 0°) as indicated for pulse 5; the signal applied to two channels includes the same amplitude (e.g., 1 ) and phase (e.g., 0°), while the signal applied to the other two channels includes the same amplitude (e.g., 1 ) and a different phase (e.g., 180°), as indicated for pulses 6-8; the signal applied to two channels includes a first amplitude (e.g., 1 ) and the same phase (e.g., 0°), while the signal applied to the other two channels includes a second amplitude (e.g., 0.5) and the same phase (e.g., 0°), as indicated for pulse 9; the signal applied to two channels includes a first amplitude (e.g., 1 ) and a first phase (e.g., 90°), while the signal applied to the other two channels includes a second amplitude (e.g., 0.5) and a second phase (e.g., 0°), as indicated for pulse 10; and the signal applied to each channel includes a different amplitude (e.g., 1 , 0.8, 0.6, or 0.4) and the same phase (e.g., 0°) as indicated for pulse 11. Accordingly, in this example, transmitting the plurality of calibration pulses may include successively pulsing (e.g., via a control portion) a different amplitude and / or phase for each coil of the array of coils for at least a portion of the plurality of calibration pulses.

[0112] Table 1230 of FIG. 12D includes a series of seven calibration pulses. During each calibration pulse, the phase of the signal applied to each channel (CH 1 to CH 3) is the same (e.g., 0°) and the amplitude (e.g., voltage) applied to each channel (CH 1 to CH 3) is either a 0 (i.e., no pulse) or a 1 (or another value). In this example, each channel is individually sequentially pulsed with a same amplitude signal as indicated for pulses 1 to 3, then each unique pair of channels is sequentially pulsed with the same amplitude signal as indicated for pulses 4 to 6, and then all three channels are pulsed with the same amplitude signal as indicated for pulse 7. Accordingly, in this example, transmitting the plurality of calibration pulses may include successively pulsing (e.g., via a control portion) each coil of the array of coils and successively pulsing (e.g., via the control portion) each subset of at least two coils of the array of coils.

[0113] Table 1240 of FIG. 12E includes a series of six calibration pulses. During each calibration pulse, the phase and / or amplitude of the signal applied to eachchannel (CH 1 to CH 3) varies. In this example, the signal applied to each channel includes a same amplitude (e.g., 1 ) and a different phase (e.g., 0°, 90°, or 180°) as indicated for pulses 1 and 2; the signal applied to each channel includes the same amplitude (e.g., 1 ) and phase (e.g., 0°) as indicated for pulse 3; the signal applied to each channel includes a different amplitude (e.g., 1 , 0.8, or 0.6) and / or a different phase (0° or 90°) as indicated for pulses 4 and 5; and the signal applied to each channel includes the same amplitude (e.g., 1 ) and a different phase (e.g., 0°, 120°, or 240°) as indicated for pulse 6. Accordingly, in this example, transmitting the plurality of calibration pulses may include successively pulsing (e.g., via a control portion) a different amplitude and / or phase for each coil of the array of coils for at least a portion of the plurality of calibration pulses.

[0114] While FIGS. 12A-12E illustrate various example sets of calibration pulses that may be used to configure a charger to wirelessly transmit power to a device, it will be apparent that other sets of calibration pulses may be used to configure a charger.

[0115] FIG. 13A is a diagram schematically representing an example system 1500 for configuring a charger (e.g., 220a-220c of FIGS. 2A-2C or 2370 of FIG. 26) for wirelessly transmitting power to a device (e.g., an IMD, such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9). System 1500 includes a trained machine learning model 1502 configured to determine outputs 1506 based on inputs 1504. In some examples, machine learning model 1502 can be used in place of and / or in addition to any of the methods 1000a-1 OOOe of FIGS. 10A-10E or method 1 100 of FIG. 1 1 . Inputs 1504 may include the relative orientation of the device with respect to the charger (e.g., VIMD from 1 104 of FIG. 11 ) and the measured electrical parameter (e.g., PIMD from 1 1 10 of FIG. 1 1 ) received by the device in response to each calibration pulse. In some examples, inputs 1504 may also include the posture of the patient. In response to the inputs 1504 (e.g., at least VIMD and / or PIMD), the outputs 1506 of machine learning model 1502 may include the X, Y, Z coordinates (e.g., location) of the device with respect to the charger, the charge coil weights (i.e., amplitude and phase for each coil of the array of coils), and / or a maximum transmit power based on a Specific Absorption Rate (SAR) limit for the patient. Machine learning model 1502 maybe trained by calculating magnetic field distributions and power coupling between the charger and the device for a multitude of locations and orientations of the device with respect to the charger.

[0116] FIG. 13B is a diagram schematically representing an example system 1510 for configuring a charger for wirelessly transmitting power to a device (e.g., IMD). System 1510 includes a trained neural network 1512 (e.g., as an example implementation of machine learning model 1502 of FIG. 13A) configured to determine the outputs 1506 based on the inputs 1504. In some examples, neural network 1512 can be used in place of and / or in addition to any of the methods 1000a-1000e of FIGS. 10A-10E or method 1 100 of FIG. 11 . As previously described with reference to FIG. 13A, inputs 1504 may include the relative orientation of the device with respect to the charger (e.g., VIMD from 1 104 of FIG. 11 ) and the measured electrical parameter (e.g., PIMD from 1 1 10 of FIG. 1 1 ) received by the device in response to each calibration pulse. In some examples, inputs 1504 may also include the posture of the patient. In response to inputs 1504 (e.g., at least VIMD and / or PIMD), the outputs 1506 of neural network 1512 may include the X, Y, Z coordinates (e.g., location) of the device with respect to the charger, the charge coil weights (i.e . , amplitude and phase for each coil of the array of coils), and / or a maximum transmit power based on a Specific Absorption Rate (SAR) limit for the patient. Neural network 1512 may be trained by calculating magnetic field distributions and power coupling between the charger and the device for a multitude of locations and orientations of the device with respect to the charger.

[0117] FIG. 14 is a diagram schematically representing magnetic fields generated by two coil channels (e.g., coil channels 1 and 2) of a charger (e.g., 220a-220c of FIGS. 2A-2C or 2370 of FIG. 26) projected over a device (e.g., an IMD, such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9). As illustrated in FIG. 14, 1 as indicated at 1601 represents the magnetic field of a first coil channel projected over the device,as indicated at 1602 represents the magnetic field of a second coil channel projected over the device, and 9 as indicated at 1604 represents the relative phase between P^ and P^. Theis indicated at 1603. As further described below with referenceto FIGS. 15-23, the magnetic field of each coil of the array of coils projected over the device may be used to determine the weight (e.g., amplitude and phase) to be applied to each coil for wirelessly transferring power from a charger to a device.

[0118] FIG. 15 is a flow diagram schematically representing an example method 1610 for configuring a charger (e.g., 220a-220c of FIGS. 2A-2C) for wirelessly transmitting power to a device (e.g., an IMD, such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9). In some examples, method 1610 may be implemented by a control portion (e.g., 190 of FIG. 1 C or 2200 of FIGS. 24A and 24B) of the charger and / or the device. At 1612, method 1610 includes transmitting a plurality of calibration pulses (e.g., 2 or 4 pulses per pair of coils) to the device via the array of coils. At 1614, method 1610 includes receiving, from the device, an electrical parameter measured by the device in response to each calibration pulse of the plurality of calibration pulses. The electrical parameter may include a power, a voltage, or a current. At 1616, method 1610 includes determining an amplitude and phase (e.g., weighting) for each coil of the array of coils based on the received electrical parameters. Additional details of method 1610 of FIG. 15 are described below with reference to FIGS. 16-23.

[0119] FIG. 16 is a flow diagram schematically representing an example method 1700 for configuring a charger (e.g., 220a-220c of FIGS. 2A-2C or 2370 of FIG. 26) for wirelessly transmitting power to a device (e.g., an IMD, such as 202a-202c of FIGS. 2A-2C, 250a-250d of FIGS. 3A-3D, or 706 of FIG. 9). At 1702, method 1700 starts, such as in response to a request to charge the device (e.g., via a remote 2230 of FIG. 24B or a user interface 2240 of FIG. 25) or in response to the charger and / or device detecting the device is within range of the charger. For the example method 1700 of FIG. 16, coil channel 1 is used as a reference channel, and each of the other channels is compared to the reference coil channel 1 . In some examples, however, any coil channel may be selected as the reference coil channel and the reference coil channel may vary during the implementation of method 1700 as long as each coil of the array of coils is addressed by method 1700 to determine a channel weighting for each coil.

[0120] At 1704, method 1700 includes setting the coil channel (C) equal to 2 (C = 2). At 1706, method 1700 includes applying a first calibration pulse to coil channel 1 (e.g., to a first coil of the array of coils). At 1708, method 1700 includes measuring a first electrical parameter (P1 ), such as a power, voltage, or current, received by the device in response to the first calibration pulse. The first electrical parameter (P1 ) may correspond to an amplitude of the signal received by the device (e.g., as representedin FIG. 14) in response to the first calibration pulse as will be further described below with reference to at least FIGS. 17-18C.

[0121] At 1710, method 1700 includes applying a second calibration pulse to coil channel C (e.g., to a second coil of the array of coils), which was initially set to coil channel 2 at 1704. At 1712, method 1700 includes measuring a second electrical parameter (P2) received by the device in response to the second calibration pulse. The second electrical parameter (P2) may correspond to an amplitude of the signal received by the device (e.g., as representedin FIG. 14) in response to the second calibration pulse. At 1714, method 1700 includes applying a third calibration pulse to the coil channels 1 and C (e.g., to the first coil and the second coil). In some examples, the third calibration pulse includes the same amplitude and phase for coil channels 1 and C. At 1716, method 1700 includes measuring a third electrical parameter (P3) received by the device in response to the third calibration pulse. The third electrical parameter (P3) may correspond to an amplitude of the signal received by the device (e.g., as may be represented by 1 +in FIG. 14 in some examples) in response to the third calibration pulse.

[0122] At 1718, method 1700 includes determining a relative phase (9) (as may be represented by 1604 in FIG. 14) between the magnetic field 1 of coil channel 1 (e.g., the first coil) and the magnetic field P^ of coil channel C (e.g., the second coil) based on the electrical parameters P1 , P2, and P3 in response to the first, second, and third calibration pulses as further described below with reference to at least FIGS. 17-180.

[0123] At 1720, method 1700 includes applying a fourth calibration pulse to coil channels 1 and C (e.g., to the first coil and the second coil) with same amplitude and with coil channel C (e.g., the second coil) phase shifted by minus the relativephase (-9) compared to coil channel 1 (e.g., the first coil). At 1722, method 1700 includes measuring a fourth electrical parameter (P4) received by the device in response to the fourth calibration pulse. The fourth electrical parameter (P4) may correspond to an amplitude of the signal received by the device in response to the fourth calibration pulse. At 1724, method 1700 includes determining whether P4 equals P1 plus P2 (i.e., does P4 = P1 + P2). If P4 equals P1 plus P2, then at 1726, the actual phase shift (OACTUAL) equals 9 (i.e., 9ACTUAL = 9). If P4 does not equal P1 plus P2, then at 1728, the actual phase shift (9ACTUAL) equals -9 (i.e., 9ACTUAL = -9). Accordingly, the actual phase shift between magnetic fields of coil channels 1 and C (e.g., the first coil and the second coil) is determined based on the received electrical parameters P1 , P2, and P4 in response to the first, second and fourth calibration pulses.

[0124] At 1730, method 1700 includes determining the channel weighting (amplitude and phase) of coils 1 and C (e.g., the first coil and the second coil) based on the electrical parameters P1 , P2, P3, and P4 in response to the first, second, third, and fourth calibration pulses as further described below with reference to at least FIGS. 17-18C.

[0125] At 1732, method 1700 determines whether C equals MAX C for the array of coils (i.e., the weighting for each coil of the array of coils has been determined if C equal MAX C). If C does not equal MAX C, then at 1734 C is incremented (C = C +1 ) and the process repeats from 1706 for the next coil channel. If C equals MAX C, then method 1700 ends at 1736. With method 1700 complete, the weighting (e.g., amplitude and phase) for each coil of the array of coils of the charger has been determined for optimizing (e.g., maximizing) wireless power transfer from the charger to the device. The corresponding weighting for each coil of the array of coils is then applied to each coil to wirelessly transfer power from the charger to the device.

[0126] FIG. 17 is a table 1800 illustrating example calibration pulses that may be transmitted to a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. The calibration pulses of table 1800 may provide calibration pulses in method 1610 of FIG. 15 or the first, second, and third calibration pulses in method 1700 of FIG. 16. Table 1800 includes a firstcalibration pulse, a second calibration pulse, and a third calibration pulse. During the first calibration pulse (e.g., at 1706 of FIG. 16), a signal having an amplitude(e.g., 1 ) is applied to coil channel 1 (CH1 ), and the first electrical parameter (P1 ) is measured by the device (e.g., at 1708 of FIG. 16). During the second calibration pulse (e.g., at 1710 of FIG. 16), a signal having the same amplitude (e.g., 1 ) and phase as the first calibration pulse is applied to coil channel 2 (CH2), and the second electrical parameter (P2) is measured by the device (e.g., at 1712 of FIG. 16). During the third calibration pulse (e.g., at 1714 of FIG. 16), a signal having the same amplitude and phase as the first calibration pulse and the second calibration pulse is applied to both coil channels 1 and 2, and the third electrical parameter (P3) is measured by the device (e.g., at 1716 of FIG. 16).

[0127] Accordingly, based on P1 , P2, and P3, in this example:P3 = | Pl + P2 cos 0 +j sin 0 | andP32= Pl2+ 2P1 • P2 • cos 0 + P22• cos 02+P22• sin 02= Pl2+ 2P1 • P2 • cos 0 + P22thus:P32- (Pl2+ P22)0 = ±cos12P1 • P2Therefore, the relative phase 9 may be calculated using the following Equation 1 :P32- (Pl2+ P22)0 = ±cos12P1 • P2

[0128] The channel weightings for coils 1 and 2 (Ai and A2) may then be calculated by:ChannelChannelwhere S is an arbitrary scaler.

[0129] While table 1800 includes coil channels 1 and 2, the table may be repeated for each additional coil (e.g., coil channels 1 and 3, coil channels 1 and 4, etc.) of the array of coils of the charger to determine the channel weighting for each coil.

[0130] FIGS. 18A-18C are signal diagrams 1810, 1820, and 1830, respectively, schematically representing example calibration pulses that may be received andmeasured by a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. As illustrated in the signal diagram 1810 of FIG. 18A, received signal 181 1 is used by the device to measure the first electrical parameter P1 (e.g., amplitude of the received signal 181 1 ) in response to the first calibration pulse of table 1800 of FIG. 17. The received signal 1812 is used by the device to measure the second electrical parameter P2 (e.g., amplitude of the received signal 1812) in response to the second calibration pulse of table 1800 of FIG. 17. The received signal 1813 is used by the device to measure the third electrical parameter P3 (e.g., amplitude of the received signal 1813, which is P1 +P2) in response to the third calibration pulse of table 1800 of FIG. 17. In the example of FIG. 18A, there is no phase difference between the received first calibration pulse 1811 and the received second calibration pulse 1812, and the second electrical parameter P2 of the received second calibration pulse 1812 equals about one-half of the first electrical parameter P1 of the received first calibration pulse 1811. The 0 degree phase difference can be calculated based on the first electrical parameter P1 from received signal 1812, the second electrical parameter P2 from received signal 1812, and the third electrical parameter P3 from received signal 1813 using the Equation 1 described above.

[0131] As illustrated in signal diagram 1820 of FIG. 18B, received signal 1821 is used by the device to measure the first electrical parameter P1 (e.g., amplitude of the received signal 1821 ) in response to the first calibration pulse of table 1800 of FIG. 17. The received signal 1822 is used by the device to measure the second electrical parameter P2 (e.g., amplitude of the received signal 1822) in response to the second calibration pulse of table 1800 of FIG. 17. The received signal 1823 is used by the device to measure the third electrical parameter P3 (e.g., amplitude of the received signal 1823, which is P1 +P2) in response to the third calibration pulse of table 1800 of FIG. 17. In the example of FIG. 18B, there is a 60 degree phase difference between the received first calibration pulse 1821 and the received second calibration pulse 1822, and the second electrical parameter P2 of the received second calibration pulse 1822 equals about one-half of the first electrical parameter P1 of the received first calibration pulse 1821 . The 60 degree (relative) phase difference can be calculated based on the first electricalparameter P1 from received signal 1821 , the second electrical parameter P2 from received signal 1822, and the third electrical parameter P3 from received signal 1823 using the Equation 1 described above.

[0132] As illustrated in the signal diagram 1830 of FIG. 18C, received signal 1831 is used by the device to measure the first electrical parameter P1 (e.g., amplitude of the received signal 1831 ) in response to the first calibration pulse of table 1800 of FIG. 17. The received signal 1832 is used by the device to measure the second electrical parameter P2 (e.g., amplitude of the received signal 1832) in response to the second calibration pulse of table 1800 of FIG. 17. The received signal 1833 is used by the device to measure the third electrical parameter P3 (e.g., amplitude of the received signal 1833) in response to the third calibration pulse of table 1800 of FIG. 17. In the example of FIG. 18C, there is a 180 degree phase difference between the received first calibration pulse 1831 and the received second calibration pulse 1832, and the second electrical parameter P2 of the received second calibration pulse 1832 equals about one-half of the first electrical parameter P1 of the received first calibration pulse 1831 . The 180 degree (relative) phase difference can be calculated based on the first electrical parameter P1 from received signal 1831 , the second electrical parameter P2 from received signal 1832, and the third electrical parameter P3 from received signal 1833 using the Equation 1 described above.

[0133] FIG. 19 is a table 1900 illustrating example calibration pulses that may be transmitted to a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. The calibration pulses of table 1900 may provide calibration pulses in method 1610 of FIG. 15 or the first, second, and third calibration pulses in method 1700 of FIG. 16. Table 1900 includes a first calibration pulse, a second calibration pulse, and a third calibration pulse. During each calibration pulse, the phase of the signal applied to each coil channel is the same. During the first calibration pulse (e.g., at 1706 of FIG. 16), a signal having a first amplitude (e.g., 1 ) is applied to coil channel 1 (CH1 ), and a signal having a second amplitude (e.g., 0.5) is applied to coil channel 2 (CH2). In response (e.g., at 1708 of FIG. 16), the first electrical parameter (P1 ) is measured by the device. Accordingly, the first calibration pulse may be represented as V1 plus 0.5 timesV2 (V1 +0.5V2), where V1 equals 1 for coil channel 1 and V2 equals 1 for coil channel 2. During the second calibration pulse (e.g., at 1710 of FIG. 16), a signal having the second amplitude (e.g., 0.5) is applied to coil channel 1 (CH1 ), and a signal having minus the first amplitude (e.g., -1 ) is applied to the coil channel 2 (CH2). In response (e.g., at 1712 of FIG. 16), the second electrical parameter (P2) is measured by the device. Accordingly, the second calibration pulse may be represented by 0.5 times V1 minus V2 (0.5V1 -V2). During the third calibration pulse (e.g., at 1714 of FIG. 16), a signal having the first amplitude (e.g., 1 ) is applied to coil channel 1 and a signal having minus the first amplitude (e.g., -1 ) is applied to coil channel 2. In response (e.g., at 1716 of FIG. 16), the third electrical parameter (P3) is measured by the device. Accordingly, the third calibration pulse may be represented by V1 minus V2 (V1 -V2). Equation 1 above may be modified based on the calibration pulses of table 1900 and the associated values V1 and V2 to determine the relative phase (0) between the magnetic field P^ of coil channel 1 and the magnetic fieldof coil channel 2 based on P1 , P2, and P3.

[0134] While table 1900 includes coil channels 1 and 2, the table may be repeated for each additional coil (e.g., coil channels 1 and 3, coil channels 1 and 4, etc.) in the array of coils of the charger to determine the channel weighting for each coil.

[0135] FIG. 20A is a table 1910 illustrating example calibration pulses that may be transmitted to a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. The calibration pulses of table 1910 may provide calibration pulses in method 1610 of FIG. 15 or the first, second, and third calibration pulses in method 1700 of FIG. 16. Table 1910 includes a first calibration pulse, a second calibration pulse, and a third calibration pulse for coil channels 1 and 2 (CH1 and CH2). The first calibration pulse (e.g., at 1706 of FIG. 16) includes a first amplitude and / or first phase (A) for coil channel 1 (CH1 ) and a second amplitude and / or second phase (B) for coil channel 2 (CH2), where “A” and “B” each represent arbitrary amplitude and phase values. In response (e.g., at 1708 of FIG. 16), the first electrical parameter (P1 ) is measured by the device. The second calibration pulse (e.g., at 1710 of FIG. 16) includes a third amplitude and / or third phase (C) for coil channel 1 (CH1 ) and a fourth amplitude and / orfourth phase (D) for coil channel 2 (CH2), where “C” and “D” each represent arbitrary amplitude and phase values. In response (e.g., at 1712 of FIG. 16), the second electrical parameter (P2) is measured by the device. The third calibration pulse (e.g., at 1714 of FIG. 16) includes a fifth amplitude and / or fifth phase (A+C) equal to the first amplitude and / or first phase (A) plus the third amplitude and / or third phase (C) for coil channel 1 (CH1 ) and a sixth amplitude and / or sixth phase (B+D) equal to the second amplitude and / or second phase (B) plus the fourth amplitude and / or fourth phase (D) for the coil channel 2 (CH2). In response (e.g., at 1716 of FIG. 16), the third electrical parameter (P3) is measured by the device.

[0136] The relative phase 0 between magnetic fields of the coil channels 1 and 2 may then be calculated using Equation 1 based on the received electrical parameters P1 , P2, and P3 in response to the first, second, and third calibration pulses as previously indicated at 1718 in FIG. 16. A fourth calibration pulse may then be applied to coil channels 1 and 2 including the same amplitude and a phase applied to the coil channel 2 shifted by minus the relative phase compared to the coil channel 1 as previously indicated at 1720 of FIG. 16. In response (e.g., at 1722 in FIG. 16), the fourth electrical parameter (P4) is measured by the device. The actual phase shift between magnetic fields of the coil channels 1 and 2 may then be determined based on the received electrical parameters P1 , P2, and P4 in response to the first, second, and fourth calibration pulses as previously indicated at 1724-1728 in FIG. 16. The channel weightings for coil channels 1 and 2 (Ai and A2) may then be calculated as follows:ChannelChannelwhere S is an arbitrary scaler.

[0137] While table 1910 includes coil channels 1 and 2, the table may be repeated for each additional coil (e.g., coil channels 1 and 3, coil channels 1 and 4, etc.) in the array of coils of the charger to determine the channel weighting for each coil.

[0138] FIG. 20B is a table 1920 illustrating example calibration pulses that may be transmitted to a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. The calibration pulses of table 1920 mayprovide calibration pulses in method 1610 of FIG. 15 or the first, second, and third calibration pulses in method 1700 of FIG. 16. Table 1920 includes a first calibration pulse, a second calibration pulse, and a third calibration pulse. Table 1920 is a specific example of table 1910 of FIG. 20A. The first calibration pulse (e.g., at 1706 of FIG. 16) includes an amplitude of 2 for coil channel 1 (CH1 ) and an amplitude of 0.5 for coil channel 2 (CH2). In response (e.g., at 1708 of FIG. 16), the first electrical parameter (P1 ) is measured by the device. The second calibration pulse (e.g., at 1710 of FIG. 16) includes an amplitude of 1 for coil channel 1 (CH1 ) and an amplitude of -1 for coil channel 2 (CH2). In response (e.g., at 1712 of FIG. 16), the second electrical parameter (P2) is measured by the device. The third calibration pulse (e.g., at 1714 of FIG. 16) includes an amplitude of 3 (2+1 ) for coil channel 1 (CH1 ) and an amplitude of -0.5 ([0.5]+[-1 ]) for coil channel 2 (CH2). In response (e.g., at 1716 of FIG. 16), the third electrical parameter P3 is measured by the device.

[0139] The relative phase 6 between magnetic fields of the coil channels 1 and 2 may then be calculated using Equation 1 based on the received electrical parameters P1 , P2, and P3 in response to the first, second, and third calibration pulses as previously indicated at 1718 in FIG. 16. A fourth calibration pulse may then be applied to coil channels 1 and 2 including the same amplitude and a phase applied to the coil channel 2 shifted by minus the relative phase compared to the coil channel 1 as previously indicated at 1720 of FIG. 16. In response (e.g., at 1722 in FIG. 16), the fourth electrical parameter (P4) is measured by the device. The actual phase shift between magnetic fields of the coil channels 1 and 2 may then be determined based on the received electrical parameters P1 , P2, and P4 in response to the first, second, and fourth calibration pulses as previously indicated at 1724-1728 in FIG. 16. The channel weightings of coil channels 1 and 2 (Ai and A2) may then be calculated as follows:Channel0.5 • e“^0ACTUAL)Channel 2: A2= S • (Pl - P2 •e’j0ACTUAL) where S is an arbitrary scaler.If SACTUAL = 0, the channel weightings for channels 1 and 2 (A1 and A2) are as follows:Channel 1 : Ar= S • (Pl • 2 + P2 ■ 0.5 ) Channel 2: A2= S • (Pl - P2) where S is an arbitrary scaler.

[0140] While table 1920 includes coil channels 1 and 2, the table may be repeated for each additional coil (e.g., coil channels 1 and 3, coil channels 1 and 4, etc.) in the array of coils of the charger to determine the channel weighting for each coil.

[0141] FIG. 21 is a table 1930 illustrating example calibration pulses that may be transmitted to a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. The calibration pulses of table 1930 may provide calibration pulses in method 1610 of FIG. 15 or the first, second, and third calibration pulses of method 1700 of FIG. 16. Table 1930 includes a first calibration pulse, a second calibration pulse, and a third calibration pulse for coil channels 1 and 2 (CH1 and CH2). The first calibration pulse (e.g., at 1706 of FIG. 16) includes a first amplitude and / or first phase (A) for coil channel 1 (CH1 ) and a second amplitude and / or second phase (B) for coil channel 2 (CH2), where “A” and “B” each represent arbitrary amplitude and phase values. In response (e.g., at 1708 of FIG. 16), the first electrical parameter (P1 ) is measured by the device. The second calibration pulse (e.g., at 1710 of FIG. 16) includes a third amplitude and / or third phase (C) for coil channel 1 (CH1 ) and a fourth amplitude and / or fourth phase (D) for coil channel 2 (CH2), where “C” and “D” each represent arbitrary amplitude and phase values. In response (e.g., at 1712 of FIG. 16), the second electrical parameter (P2) is measured by the device. The third calibration pulse (e.g., at 1714 of FIG. 16) includes a fifth amplitude and / or fifth phase (E) for coil channel 1 (CH1 ) and a sixth amplitude and / or sixth phase (F) for coil channel 2 (CH2), where “E” and “F” each represent arbitrary amplitude and phase values. In response (e.g., at 1716 of FIG. 16), the third electrical parameter P3 is measured by the device.

[0142] The relative phase 0 between magnetic fields of the coil channels 1 and 2 may then be calculated based on the received electrical parameters P1 , P2, and P3 in response to the first, second, and third calibration pulses. The arbitrary values A, B, C, D, E, and F are complex numbers describing the amplitude andphase of each calibration pulse applied to channels 1 and 2. Since the third calibration pulse weights are E and F, the third calibration pulse weights can be represented as a linear combination of pulses 1 and 2 as follows:Pl = A ■ VI + B ■ V2P2 = C - VI + D - V2P3 = E ■ VI + F ■ V2 = X ■ Pl + Y ■ P2 where X and Y are non-zero.P12 can be determined using P1 , P2, and P3 and follows:P12 = P32— Pl • P2 • (2 — 2XY) - (P12(X2- 1) + P22(Y2- 1))Therefore, the relative phase 0 can be calculated as follows:P122- (Pl2+ P220 = ±cos12P1 • P2

[0143] A fourth calibration pulse may then be applied to coil channels 1 and 2 including the same amplitude and a phase applied to the coil channel 2 shifted by minus the relative phase compared to the coil channel 1 as previously indicated at 1720 of FIG. 16. In response (e.g., at 1722 in FIG. 16), the fourth electrical parameter (P4) is measured by the device. The actual phase shift between magnetic fields of the coil channels 1 and 2 may then be determined based on the received electrical parameters P1 , P2, and P4 in response to the first, second, and fourth calibration pulses as previously indicated at 1724-1728 of FIG. 16. The channel weightings of coil channels 1 and 2 (Ai and A2) may then be calculated as follows:Channel 1 : A±= S • (Pl • A + P2 • C ■e~j2eAC™M) Channel 2: A2= S • (Pl • B + P2 • D . g~ J ACTUAL where S is an arbitrary scaler.

[0144] While table 1930 includes coil channels 1 and 2, the table may be repeated for each additional coil (e.g., coil channels 1 and 3, coil channels 1 and 4, etc.) in the array of coils of the charger to determine the channel weighting for each coil.

[0145] FIG. 22 is a table 2000 illustrating example calibration pulses that may be transmitted to a device (e.g., IMD) for configuring a charger for wirelessly transmitting power to the device. Table 2000 includes a first calibration pulse and a second calibration pulse. The first calibration pulse includes a first amplitude and / or first phase (A) for coil channel 1 (CH1 ) and a second amplitude and / or second phase (B) for coil channel 2 (CH2), where “A” and “B” each represent arbitrary amplitude and phase values. In response, the first electrical parameter (P1 ) is measured by the device. The second calibration pulse includes a third amplitude and / or third phase (C) for coil channel 1 (CH1 ) and a fourth amplitude and / or fourth phase (D) for coil channel 2 (CH2), where “C” and “D” each represent arbitrary amplitude and phase values. In response, the second electrical parameter (P2) is measured by the device. In addition, the phase difference (QACTUAL) between the first calibration pulse and the second calibration pulse is measured by the device. In this embodiment, since the device measures the actual phase difference, a third calibration pulse and a fourth calibration pulse are not needed to determine the actual phase difference.

[0146] Accordingly, the channel weightings for coil channel 1 and 2 (Ai and A2) are as follows:ChannelChannel 2: A2= S • (Pl • B + P2 • D •e- ^°ACTUAL) where S is an arbitrary scaler.If A =1 , B = 0, C = 0, and D = 1 , the channel weightings for coil channel 1 and 2 (A1 and A2) are as follows:Channel 1 A = S • PlChannel 2: A2= S • P2 . g ~J9ACTUAL where S is an arbitrary scaler.

[0147] While table 2000 includes coil channels 1 and 2, the table may be repeated for each additional coil (e.g., coil channels 1 and 3, coil channels 1 and 4, etc.) in the array of coils of the charger to determine the channel weighting for each coil.

[0148] FIG. 23 is a signal diagram 2010 schematically representing example calibration pulses that may be received and measured by a device (e.g., IMD) forconfiguring a charger for wirelessly transmitting power to the device. As illustrated in the signal diagram 2010 of FIG. 23, received signal 2011 is used by the device to measure the first electrical parameter P1 (e.g., amplitude of the received signal 2011 ) in response to the first calibration pulse of table 2000 of FIG. 22. The received signal 2012 is used by the device to measure the second electrical parameter P2 (e.g., amplitude of the received signal 2012) in response to the second calibration pulse of table 2000 of FIG. 22. Both received signals 2011 and 2012 are used by the device to measure the actual phase difference (SACTUAL) 2014 between the received signals 2011 and 2012. Accordingly, a third calibration pulse and a fourth calibration pulse are not needed in this example to determine the actual phase difference between the first calibration pulse and the second calibration pulse since the device measures the actual phase difference directly and transmits the actual phase difference to the charger along with the first electrical parameter P1 and the second electrical parameter P2.

[0149] FIG. 24A is a block diagram schematically representing an example control portion 2200. In some examples, control portion 2200 provides one example implementation of a control portion forming a part of, implementing, and / or generally managing stimulation elements, power / control elements (e.g., pulse generators, microstimulators), wireless receivers, wireless transmitters, transceivers, sensors, and related elements, devices, user interfaces, instructions, information, engines, elements, functions, actions, and / or methods, as described throughout examples of the present disclosure in association with FIGS. 1A-23.

[0150] In some examples, control portion 2200 includes a controller 2202 and a memory 2210. In general terms, controller 2202 of control portion 2200 comprises at least one processor 2204 and associated memories. The controller 2202 is electrically coupled to, and in communication with, memory 2210 to generate control signals to direct operation of at least some of the stimulation elements, power / control elements (e.g., pulse generators, microstimulators), wireless receivers, wireless transmitters, transceivers, sensors, and related elements, devices, user interfaces, instructions, information, engines, elements, functions, actions, and / or methods, as described throughout examples of thepresent disclosure. In some examples, these generated control signals include, but are not limited to, employing instructions 221 1 and / or information 2212 stored in memory 2210 for at least controlling the charging of a power element (e.g., 204 of FIGS. 2A-2C or 3B-3D), controlling a stimulation element (e.g., 256 of FIG. 3A, 30, or 3D), and / or controlling a sensing element (e.g., 258 of FIG. 3D). Such control may comprise part of diagnosing and / or directing and managing treatment of sleep disordered breathing such as obstructive sleep apnea, hypopnea, and / or central sleep apnea, with such control also comprising sensing physiologic information including but not limited to electrical brain activity, respiratory information, cardiac information, and / or monitoring sleep disordered breathing, etc. In some instances, the controller 2202 or control portion 2200 may sometimes be referred to as being programmed to perform the above-identified actions, functions, etc. such that the controller 2202, control portion 2200 and any associated processors may sometimes be referred to as being a special purpose computer, control portion, controller, or processor. In some examples, at least some of the stored instructions 221 1 are implemented as, or may be referred to as, a care engine, a sensing engine, monitoring engine, and / or treatment engine. In some examples, at least some of the stored instructions 221 1 and / or information 2212 may form at least part of, and / or, may be referred to as a care engine, sensing engine, monitoring engine, and / or treatment engine.

[0151] In response to or based upon commands received via a user interface (e.g., user interface 2240 in FIG. 25) and / or via machine-readable instructions, controller 2202 generates control signals as described above in accordance with at least some of the examples of the present disclosure. In some examples, controller 2202 is embodied in a general purpose computing device while in some examples, controller 2202 is incorporated into or associated with at least some of the stimulation elements, power / control elements (e.g., pulse generators, microstimulators), wireless receivers, wireless transmitters, transceivers, sensors, and related elements, devices, user interfaces, instructions, information, engines, functions, actions, and / or methods, etc. as described throughout examples of the present disclosure.

[0152] For purposes of this application, in reference to the controller 2202, the term “processor” shall mean a presently developed or future developed processor (or processing resources) that executes machine-readable instructions contained in a memory. In some examples, execution of the machine-readable instructions, such as those provided via memory 2210 of control portion 2200 cause the processor to perform the above-identified actions, such as operating controller 2202 to implement the charging, sensing, monitoring, determining, calculating, treatment, etc. as generally described in (or consistent with) at least some examples of the present disclosure. The machine-readable instructions may be loaded in a random access memory (RAM) for execution by the processor from their stored location in a read only memory (ROM), a mass storage device, or some other persistent storage (e.g., non-transitory tangible medium or nonvolatile tangible medium), as represented by memory 2210. In some examples, the machine-readable instructions may comprise a sequence of instructions, a processor-executable data model (e.g., machine learning, other), or the like. In some examples, memory 2210 comprises a computer readable tangible medium providing non-volatile storage of the machine-readable instructions executable by a process of controller 2202. In some examples, the computer readable tangible medium may sometimes be referred to as, and / or comprise at least a portion of, a computer program product. In some examples, hard wired circuitry may be used in place of or in combination with machine-readable instructions to implement the functions described. For example, controller 2202 may be embodied as part of at least one application-specific integrated circuit (ASIC), at least one field-programmable gate array (FPGA), and / or the like. In at least some examples, the controller 2202 is not limited to any specific combination of hardware circuitry and machine-readable instructions, nor limited to any particular source for the machine-readable instructions executed by the controller 2202.

[0153] In some examples, control portion 2200 may be entirely implemented within or by a stand-alone device. In some examples, the control portion 2200 may be partially implemented in one of the sensing devices, monitoring devices, stimulation devices, apnea treatment devices (or portions thereof), etc. and partially implemented in a computing resource separate from, and independentof, the apnea treatment devices (or portions thereof) but in communication with the apnea treatment devices (or portions thereof). For instance, in some examples control portion 2200 may be implemented via a server accessible via the cloud and / or other network pathways. In some examples, the control portion 2200 may be distributed or apportioned among multiple devices or resources such as among a server, an apnea treatment device (or portion thereof), and / or a user interface. In some examples, control portion 2200 includes, and / or is in communication with, a user interface 2240 as shown in FIG. 25.

[0154] Figure 24B is a diagram schematically illustrating at least some example implementations of a control portion 2220 by which the control portion 2200 (FIG. 24A) can be implemented, according to one example of the present disclosure. In some examples, control portion 2220 is entirely implemented within or by a medical device 2225 (e.g., implantable pulse generator (IPG) assembly in some examples), which has at least some of substantially the same features and attributes as a medical device as previously described throughout the present disclosure. In some examples, control portion 2220 is entirely implemented within or by a remote control 2230 (e.g., a programmer) external to the patient’s body, such as a patient control 2232 and / or a physician control 2234. In some examples, the control portion 2200 is partially implemented in the medical device 2225 and partially implemented in the remote control 2230 (at least one of patient control 2232 and physician control 2234).

[0155] FIG. 25 is a block diagram schematically representing user interface 2240, according to one example of the present disclosure. In some examples, the user interface 2240 forms part of and / or is accessible via a device external to the patient and by which the therapy system may be at least partially controlled and / or monitored. The external device which hosts user interface 2240 may be a patient remote (e.g., 2232 in FIG. 24B), a physician remote (e.g., 2234 in FIG. 24B) and / or a clinician portal. In some examples, the user interface 2240 comprises a user interface or other display that provides for the simultaneous display, activation, and / or operation of at least some of the stimulation elements, power / control elements (e.g., pulse generators, microstimulators), wireless receivers, wireless transmitters, transceivers, sensors, and related elements,devices, user interfaces, instructions, information, engines, functions, actions, and / or method, etc., as described in association with FIGS. 1 A-23. In some examples, at least some portions or aspects of the user interface 2240 are provided via a graphical user interface (GUI) and may comprise a display 2244 and input 2242.

[0156] FIG. 26 is a block diagram 2300 which schematically represents some example implementations by which a medical device (e.g., IMD) 2310, such as a pulse generator and / or sensing monitor (either or both of which may be implantable in some examples), may communicate wirelessly with external devices outside the patient. As shown in FIG. 26, in some examples, the IMD 2310 may communicate with at least one of a patient app 2330 on a mobile device 2320, a patient remote control 2340, a clinician programmer 2350, a patient management tool 2360, and an external charger 2370. The patient management tool 2360 may be implemented via a cloud-based portal 2362, the patient app 2330, and / or the patient remote control 2340. Among other types of data, these communication arrangements enable the IMD 2310 to communicate, display, manage, etc. data for wirelessly charging or powering IMD 2310 and / or for patient management as well as to allow for adjustment to control information (e.g., 2212 of FIG. 24A) if / where needed. It will be understood that at least some of the various devices / elements 2320, 2340, 2350, patient management tool 2360, and external charger 2370 also may communicate with each other, with or without communicating with the medical device 2310.

[0157] Although specific examples have been illustrated and described herein, a variety of alternate and / or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.

Claims

CLAIMSWhat is claimed is:1 . A system compromising: a device comprising a wireless receiver to receive power for the device; and a charger comprising: a wireless transmitter to transmit the power to the wireless receiver of the device, the wireless transmitter comprising an array of coils; and a control portion configured to determine an amplitude and phase for each coil of the array of coils.

2. The system of claim 1 , wherein the control portion is configured to determine a relative location of the device with respect to the charger.

3. The system of claim 2, wherein to determine the relative location of the device with respect to the charger, the control portion is configured to: transmit a plurality of calibration pulses to the device via the array of coils; receive, from the device, a measured electrical parameter coupled to the device in response to each calibration pulse of the plurality of calibration pulses; and determine the relative location of the device with respect to the charger based on a relative orientation of the device with respect to the charger, a magnetic field distribution of each coil of the array of coils, and the measured electrical parameter coupled to the device in response to each calibration pulse of the plurality of calibration pulses.

4. The system of claim 1 , wherein to determine the amplitude and phase for each coil of the array of coils, the control portion is configured to: determine a relative location of the device with respect to the charger; and determine a relative orientation of the device with respect to the charger.

5. The system of claim 4, wherein the control portion is configured to determine the relative location of the device with respect to the charger based on at least one of a pressure sensor signal, a posture of a patient in which the device is implanted, and / or a received signal strength indicator (RSSI) of a radio frequency (RF) signal emitted from the device.

6. The system of claim 1 , wherein to determine the amplitude and phase for each coil of the array of coils, the control portion is configured to: transmit a plurality of calibration pulses to the device via the array of coils; receive, from the device a measured electrical parameter coupled to the device in response to each calibration pulse of the plurality of calibration pulses; locate the device relative to the charger based on a relative orientation of the device with respect to the charger, a magnetic field distribution of each coil of the array of coils, and the measured electrical parameter coupled to the device in response to each calibration pulse of the plurality of calibration pulses; and determine the amplitude and phase for each coil of the array of coils based on the location of the device relative to the charger.

7. The system of claim 6, wherein the electrical parameter comprises a power, a voltage, or a current.

8. The system of claim 6, wherein to transmit the plurality of calibration pulses to the device, the control portion is configured to: successively pulse each coil of the array of coils; and successively pulse each subset of two coils of the array of coils.

9. The system of claim 6, wherein to transmit the plurality of calibration pulses to the device, the control portion is configured to: successively pulse subsets of at least two coils of the array of coils comprising a first amplitude for a first coil of the at least two coils and a second amplitude for a second coil of the at least two coils.

10. The system of claim 6, wherein to transmit the plurality of calibration pulses to the device, the control portion is configured to: successively pulse the array of coils comprising a different amplitude and / or phase for each coil of the array of coils for at least a portion of the plurality of calibration pulses.

11. The system of claim 6, wherein the control portion is configured to determine the relative orientation of the device with respect to the charger.

12. The system of claim 1 1 , wherein to determine the relative orientation of the device with respect to the charger, the control portion is configured to: receive, from the device, an orientation of the device with respect to gravity; measure, via the charger, an orientation of the charger with respect to gravity; and determine the relative orientation of the device with respect to the charger based on the orientation of the device with respect to gravity and the orientation of the charger with respect to gravity.

13. The system of claim 1 , wherein the control portion is configured to transmit power to the device by applying the corresponding amplitude and phase to each coil of the array of coils.

14. The system of claim 1 , wherein the device comprises a power element and the wireless receiver receives the power to charge the power element.

15. The system of claim 1 , wherein the device comprises an implantable medical device, an injectable medical device, or an insertable medical device.

16. The system of claim 1 , wherein the device comprises a wearable medical device or a wearable consumer device.

17. The system of claim 1 , wherein the device comprises a medical device, a diagnostic device, a hearing aid, or a wireless earbud.

18. A system compromising: a device comprising a wireless receiver to receive power for the device; and a charger comprising: a wireless transmitter to transmit the power to the wireless receiver of the device, the wireless transmitter comprising an array of coils; and a control portion configured to: transmit a plurality of calibration pulses to the device via the array of coils; receive, from the device, an electrical parameter measured by the device in response to each calibration pulse of the plurality of calibration pulses; and determine an amplitude and phase for each coil of the array of coils based on the received electrical parameters.

19. The system of claim 18, wherein the electrical parameter comprises a power, a voltage, or a current.

20. The system of claim 18, wherein to transmit the plurality of calibration pulses to the device via the array of coils, the control portion is configured to: apply a first calibration pulse of the plurality of calibration pulses to a first coil of the array of coils; apply a second calibration pulse of the plurality of calibration pulses to a second coil of the array of coils; apply a third calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising a same amplitude and phase; calculate a relative phase between magnetic fields of the first coil and the second coil based on the received electrical parameters in response to the first, second, and third calibration pulses;apply a fourth calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising the same amplitude and a phase applied to the second coil shifted by minus the relative phase compared to the first coil; and determine the actual phase shift between magnetic fields of the first coil and the second coil based on the received electrical parameters in response to the first, second, and fourth calibration pulses.

21. The system of claim 18, wherein to transmit the plurality of calibration pulses to the device via the array of coils, the control portion is configured to: apply a first calibration pulse of the plurality of calibration pulses to a first coil and a second coil of the array of coils comprising a first amplitude and / or a first phase for the first coil and a second amplitude and / or a second phase for the second coil; apply a second calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising a third amplitude and / or a third phase for the first coil and a fourth amplitude and / or a fourth phase for the second coil; apply a third calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising a fifth amplitude and / or a fifth phase equal to the first amplitude and / or the first phase plus the third amplitude and / or the third phase for the first coil and a sixth amplitude and / or a sixth phase equal to the second amplitude and / or the second phase plus the fourth amplitude and / or the fourth phase for the second coil; calculate a relative phase between magnetic fields of the first coil and the second coil based on the received electrical parameters in response to the first, second, and third calibration pulses; apply a fourth calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising the same amplitude and a phase applied to the second coil shifted by minus the relative phase compared to the first coil; anddetermine the actual phase shift between magnetic fields of the first coil and the second coil based on the received electrical parameters in response to the first, second, and fourth calibration pulses.

22. The system of claim 18, wherein to transmit the plurality of calibration pulses to the device via the array of coils, the control portion is configured to: apply a first calibration pulse of the plurality of calibration pulses to a first coil and a second coil of the array of coils comprising a first amplitude and / or a first phase for the first coil and a second amplitude and / or a second phase for the second coil; apply a second calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising a third amplitude and / or a third phase for the first coil and a fourth amplitude and / or a fourth phase for the second coil; apply a third calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising a fifth amplitude and / or a fifth phase for the first coil and a sixth amplitude and / or a sixth phase for the second coil; calculate a relative phase between magnetic fields of the first coil and the second coil based on the received electrical parameters in response to the first, second, and third calibration pulses; apply a fourth calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising the same amplitude and a phase applied to the second coil shifted by minus the relative phase compared to the first coil; and determine the actual phase shift between magnetic fields of the first coil and the second coil based on the received electrical parameters in response to the first, second, and fourth calibration pulses.

23. The system of claim 18, wherein to transmit the plurality of calibration pulses to the device via the array of coils, the control portion is configured to: apply a first calibration pulse of the plurality of calibration pulses to a first coil and a second coil of the array of coils comprising a first amplitude and / or afirst phase for the first coil and a second amplitude and / or a second phase for the second coil; apply a second calibration pulse of the plurality of calibration pulses to the first coil and the second coil comprising a third amplitude and / or a third phase for the first coil and a fourth amplitude and / or a fourth phase for the second coil; and receive an actual phase shift between magnetic fields of the first coil and the second coil measured by the device in response to the first and second calibration pulses.

24. The system of claim 18, wherein the control portion is configured to: determine a relative orientation of the device with respect to the charger; wherein each calibration pulse is transmitted from a single coil of the array of coils and / or a subset of at least two coils of the array of coils; and input the relative orientation of the device with respect to the charger and the received electrical parameter coupled to the device in response to each calibration pulse to a trained machine learning model to determine a location of the device with respect to the charger at an output of the machine learning model.

25. The system of claim 24, wherein the control portion is configured to determine the amplitude and phase for each coil of the array of coils based on the location of the device with respect to each coil of the array of coils.

26. The system of claim 24, wherein the machine learning model comprises a neural network.

27. The system of claim 18, wherein the control portion is configured to: determine a relative orientation of the device with respect to the charger; wherein each calibration pulse is transmitted from a single coil of the array of coils and / or a subset of at least two coils of the array of coils; and input the relative orientation of the device with respect to the charger and the received electrical parameter coupled to the device in response to each calibration pulse to a trained machine learning model to determine the amplitudeand phase of each coil of the array of coils at an output of the machine learning model.

28. The system of claim 18, wherein the control portion is configured to: determine a relative orientation of the device with respect to the charger; wherein each calibration pulse is transmitted from a single coil of the array of coils and / or a subset of at least two coils of the array of coils; and input the relative orientation of the device with respect to the charger and the received electrical parameter coupled to the device in response to each calibration pulse to a trained machine learning model to determine a maximum transmit power within a Specific Absorption Rate (SAR) limit at an output of the machine learning model.

29. The system of claim 18, wherein the control portion is configured to transmit power to the device by applying the corresponding amplitude and phase to each coil of the array of coils.

30. The system of claim 18, wherein the device comprises a power element and the wireless receiver receives the power to charge the power element.31 . A system compromising: an implantable medical device configured to be implanted in a patient, the device comprising: a power element; and a wireless receiver to receive power for the device; and a charger comprising: a wireless transmitter to transmit the power to the wireless receiver of the device, the wireless transmitter comprising an array of coils; and a control portion configured to adjust an amplitude and phase applied to each coil of the array of coils to transmit power to the device based on a location of the device with respect to the charger.

32. The system of claim 31 , wherein the control portion is configured to: determine a relative orientation of the device with respect to the charger; calculate a magnetic field of each coil of the array of coils relative to the device based on the orientation of the device with respect to the charger and a magnetic field distribution of each coil of the array of coils; transmit a plurality of calibration pulses to the device, each calibration pulse transmitted from a single coil of the array of coils and / or a subset of at least two coils of the array of coils; receive, from the device, a measured electrical parameter coupled to the device in response to each calibration pulse; determine the location of the device with respect to the charger based on the received electrical parameter coupled to the device in response to each calibration pulse; and determine the amplitude and phase for each coil of the array of coils based on the location of the device with respect to each coil of the array of coils.

33. The system of claim 31 , wherein the control portion is configured to: apply a first calibration pulse to a first coil of the array of coils; receive, from the device, a measured first electrical parameter received by the device in response to the first calibration pulse; apply a second calibration pulse to a second coil of the array of coils; receive, from the device, a measured second electrical parameter received by the device in response to the second calibration pulse; apply a third calibration pulse to the first coil and the second coil comprising a same amplitude and phase; receive, from the device, a measured third electrical parameter received by the device in response to the third calibration pulse; calculate a relative phase between magnetic fields of the first coil and the second coil based on the first electrical parameter, the second electrical parameter, and the third electrical parameter;apply a fourth calibration pulse to the first coil and the second coil comprising the same amplitude and comprising a phase applied to the second coil shifted by minus the relative phase compared to the first coil; receive, from the device, a measured fourth electrical parameter received by the device in response to the fourth calibration pulse; determine the actual phase shift between magnetic fields of the first coil and the second coil equals the relative phase in response to the fourth electrical parameter being equal to the first electrical parameter plus the second electrical parameter; determine the actual phase shift between magnetic fields of the first coil and the second coil equals minus the relative phase in response to the fourth electrical parameter not being equal to the first electrical parameter plus the second electrical parameter; and determine the amplitude and phase of the first coil and the second coil based on the actual phase shift between the magnetic fields of the first coil and the second coil.

34. The system of claim 31 , wherein the array of coils comprises: a first coil; a second coil partially overlapping the first coil; and a third coil partially overlapping the first coil and partially overlapping the second coil.

35. The system of claim 31 , wherein the array of coils comprises: a first coil; a second coil partially overlapping the first coil; a third coil partially overlapping the second coil; and a fourth coil partially overlapping the third coil and partially overlapping the first coil.

36. The system of claim 31 , wherein the array of coils comprises: a first coil;a second coil partially overlapping the first coil; a third coil partially overlapping the second coil; and a fourth coil partially overlapping the third coil, partially overlapping the second coil, and partially overlapping the first coil.

37. The system of claim 31 , wherein the array of coils comprises: a first coil; a second coil partially overlapping the first coil; a third coil partially overlapping the second coil; a fourth coil partially overlapping the third coil, partially overlapping the second coil, and partially overlapping the first coil; and a fifth coil partially overlapping the fourth coil and partially overlapping the first coil.

38. The system of claim 31 , wherein the array of coils comprises: a first coil; a second coil partially overlapping the first coil; a third coil partially overlapping the second coil and partially overlapping the first coil; a fourth coil partially overlapping the third coil; a fifth coil partially overlapping the fourth coil, partially overlapping the third coil, and partially overlapping the second coil; and a sixth coil partially overlapping the fifth coil and partially overlapping the second coil.

39. The system of claim 31 , wherein the array of coils comprises: a first coil; a second coil partially overlapping the first coil; a third coil partially overlapping the second coil; a fourth coil partially overlapping the third coil and partially overlapping the second coil;a fifth coil partially overlapping the fourth coil, partially overlapping the second coil, and partially overlapping the first coil; a sixth coil partially overlapping the fifth coil; a seventh coil partially overlapping the sixth coil, partially overlapping the fifth coil, and partially overlapping the fourth coil; and an eighth coil partially overlapping the seventh coil and partially overlapping the fourth coil.

40. The system of claim 31 , wherein each coil of the array of coils comprises a spiral coil.41 . The system of claim 31 , wherein the control portion is configured to adjust an amplitude and phase applied to each coil of the array of coils to transmit power to the medical device based on a Specific Absorption Rate (SAR) limit.

42. The system of claim 31 , wherein the implantable medical device comprises an element to treat sleep disordered breathing.

43. A charger comprising: a wireless transmitter to transmit power to a wireless receiver of a device, the wireless transmitter comprising an array of coils; and a control portion configured to: determine a location of the device relative to the charger; and determine an amplitude and phase for each coil of the array of coils based on the location of the device relative to the charger.

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