System and method for transferring energy to an implant

Abstract

A system for transferring energy to an implant, the system comprising one or more transmitters configured to transmit one or more corresponding energy transfer signals to the implant; the implant comprises an electrically powered functional module and an implant receiver associated with the functional module, the implant receiver being configured for receiving the energy transfer signals, and converting at least part of the energy transfer signals into an electrical implant signal for powering the implant; the implant further comprises a passive backscatter module associated with the implant receiver, the passive backscatter module being configured, responsive to the implant receiver receiving the energy transfer signals, for passively causing at least one reflection signal to be reflected from the implant receiver; the system also comprises a monitoring unit configured for receiving the reflection signal, and a control module associated with the monitoring unit, and configured, based on a reflection power of the received reflection signal, to control transmission parameters of the transmitters.

Description

[0001] SYSTEM AND METHOD FOR TRANSFERRING ENERGY TO AN IMPLANT

[0002] TECHNICAL FIELD

[0003] The invention relates to a system and method for transferring energy to an implant. The invention further relates to a flexible patch for powering or charging an implant and a method for powering or charging the implant using the flexible patch.

[0004] BACKGROUND

[0005] Conventionally, medical implants placed inside a patient’s body are powered by batteries that are depleted over time. In order to replace a battery of a medical implant, the patient has to undergo a costly and difficult surgical procedure to replace the battery and possibly suffer surgical complications.

[0006] To address this problem, technologies allowing for non-invasive energy transfer to implants have been proposed. However, existing technologies fail to accurately assess the amount of energy absorbed by a patient's tissue during an energy transfer process. This is problematic since excessive energy absorption in tissue can lead to potential health risks, including heating and mechanical damage. In addition, existing technologies that assess the amount of energy absorbed by a patient’s tissue are often reliant on costly and complex external devices that suffer from operational delays, further compounding inefficiencies in energy transfer to the implant and elevating safety risks for the patient.

[0007] Accordingly, it is an object of the present disclosure to provide a new system and method for non-invasively transferring energy to an implant safely and efficiently.

[0008] References considered to be relevant as background to the presently disclosed subject matter are listed below. Acknowledgement of the references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter. U.S. Patent No. 11,369,267 B2, published on June 28, 2022, describes a reconfigurable implantable system for ultrasonic power control and telemetry. It includes a charging device that includes an ultrasonic transducer to transmit and receive ultrasonic signals transmitted through a biological body, and a signal generator to drive the ultrasonic transducer to transmit an ultrasonic charging signal through the biological body. The system further includes an implantable device configured to communicate wirelessly with the charging device through the biological body via an ultrasonic communication link between the implantable device and the charging device. An implantable ultrasonic transducer receives the ultrasonic charging signal from the charging device and transmits ultrasonic signals through the biological body. A power unit coupled to the ultrasonic transducer harvests energy from the received ultrasonic charging signal when the implantable device is in an energy harvesting mode. A communication unit is configured to switch the implantable device between the energy harvesting mode and an ultrasonic communication mode, and to read data from the sensing or actuation unit and transmit the data through the implantable ultrasonic transducer when the implantable device is in the ultrasonic communication mode.

[0009] International Patent Application Publication No. 2022046770 Al, published on March 3, 2022, describes method and system embodiments for discovering or tracking a device implantable in a subject using ultrasonic waves. The method for tracking the implantable device can include establishing a synchronization state with the implantable device, estimating a location of the implantable device, and determining whether to maintain or to adjust where an ultrasonic beam is being focused based on ultrasonic signal strength. The method for discovering an implantable device powered using ultrasonic waves can include emitting an ultrasonic beam to successively focus on a plurality of focal points, receiving ultrasonic backscatter corresponding to the ultrasonic beam focused on the focal point, and comparing the received ultrasonic backscatter with a predetermined pattern associated with the implantable device to be discovered to generate a score indicating how likely the ultrasonic backscatter comprises the predetermined pattern; and determining a location of the implantable device based on the scores.

[0010] U.S. Patent Application Publication No. 20220062650 Al, published on March 3,

[0011] 2022, describes method and system embodiments for controlling power provided to a device implantable in a subject. In some embodiments, a method is performed at the implantable device to receive, from an interrogator, powering ultrasonic waves having a wave power. Then, energy from the powering ultrasonic waves is converted into an electrical signal to power the implantable device. Information that indicates whether more power or less power should be transmitted to the implantable device is transmitted to the interrogator.

[0012] U.S. Patent No. 10,589,108 B2, published on March 17, 2020, and U.S. Patent No. 10,252,066 B2, published on April 9, 2019, describe a system for providing energy to a bio-implantable medical device that includes an acoustic energy delivery device and a bio-implantable electro-acoustical energy converter. The acoustic energy delivery device generates acoustic energy with a multi-dimensional array of transmitting electroacoustical transducers. The acoustic energy is received by one or more receiving electroacoustical transducers in the bio-implantable electro-acoustical energy converter. The receiving electro-acoustical transducers convert the acoustic energy to electrical energy to power the bio-implantable medical device directly or indirectly. An external alignment system provides lateral and / or angular positioning of an ultrasound energy transmitter over an ultrasound energy receiver. The acoustic energy transmitter alignment system comprises either or both x-y-z plus angular positioning components, and / or a substantially multi-dimensional array of transmitters plus position sensors in both the transmitter and receiver units.

[0013] U.S. Patent No. 8,974,366 Bl, published on March 10, 2015, provides a bioimplantable energy capture and storage assembly. The assembly includes an acoustic energy transmitter and an acoustic energy receiver. The acoustic energy receiver also functions as an energy converter for converting acoustic energy to electrical energy. An electrical energy storage device is connected to the energy converter, and is contained within a bio-compatible implant for implantation into tissue. The acoustic energy transmitter is separate from the implant, and comprises a substantially 2-dimensional array of transmitters. The acoustic energy converter may also provide conditioned power directly to a load, connected to the energy converter.

[0014] Ghanbari et al., “Optimizing Volumetric Efficiency and Modeling Backscatter Communication in Biosensing Ultrasonic Implants,” IEEE, 16 July 2020, provides a systematic design approach for an implant piezoceramic geometry and operation frequency to minimize the overall volume of the implant. European Patent No. 3,568,879 Bl, published on May 29, 2024, discloses a conformable piezoelectric transducer array for performing ultrasound or the like, including a silicone elastomer substrate and a silicone elastomer superstate. A plurality of piezoelectric transducer elements is disposed between the substrate and superstate. A first electrical interconnect layer electrically interconnects a first surface of the transducer elements adjacent to the substrate and a second electrical interconnect layer electrically interconnecting a second surface of the transducer elements adjacent to the superstate.

[0015] Rathod, “A Review of Acoustic Impedance Matching Techniques for Piezoelectric Sensors and Transducers,” MDPI, Sensors 2020, 20, 4051, presents standard methods to match an acoustic impedance of piezoelectric sensors, actuators and transducers with the surrounding wave propagation media.

[0016] Hu et al., “Stretchable Ultrasonic Transducer Arrays for Three-Dimensional Imaging on Complex Surfaces,” Sci. Adv. 2018; 4, 23 March 2018, reports a stretchable ultrasound probe that can conform to nonplanar complex surfaces.

[0017] GENERAL DESCRIPTION

[0018] In accordance with a first aspect of the presently disclosed subject matter, there is provided a system for transferring energy to an implant, the system comprising: one or more transmitters configured to transmit one or more corresponding energy transfer signals to the implant; said implant comprising: o an electrically powered functional module; o an implant receiver associated with the functional module, said implant receiver being configured for receiving said energy transfer signals, and converting at least part of said energy transfer signals into an electrical implant signal for powering said implant; and o a passive backscatter module associated with said implant receiver, said passive backscatter module being configured, responsive to said implant receiver receiving said energy transfer signals, for passively causing at least one reflection signal to be reflected from said implant receiver; a monitoring unit configured for receiving said reflection signal; and a control module associated with said monitoring unit, and configured, based on a reflection power of said received reflection signal, to control transmission parameters of said transmitters.

[0019] The energy transfer signals may be configured for being transmitted through a medium towards said implant, wherein said control module is configured for calculating at least one of the following: (a) the power absorbed in the medium, (b) the reflection power of the received reflection signal, and (c) the power absorbed in the implant. Calculating these parameters allows the system to determine how much of the energy of transmitted energy transfer signals were actually converted to implant power, and how much energy was lost, allowing the control module to assess the efficiency of the transmission and adjust transmission parameters continuously to improve efficiency.

[0020] In accordance with one example, this calculation may be based on subtraction of the effectively reflected power, which accounts for both forward and backward transmission losses, from the power transmitted to the implant. Predefined algorithms may be used to accurately account for these transmission losses, ensuring the precise management of the energy utilized by the implant. Thus, the control module may be configured for calculating the implant power of the electrical implant signal.

[0021] In accordance with one design variation, the system may comprise a single transmitter. In accordance with another design variation, the system may comprise an array of transmitters, which may be arranged in a grid. Specifically, the transmitters may be arranged in rows and columns, either aligned or offset with respect to one another, to cover a given area. In accordance with a specific example, the arrangement may be such that the distance between any two adjacent transmitters is approximately X / 2, X being the nominal wavelength of the energy transfer signal.

[0022] In the above example, for each respective transmitter of said two or more transmitters, said control module may be configured, based on said absorbed power and said implant power, to control given parameters of said transmission parameters, said given parameters including an amplitude and a phase of said respective transmitter.

[0023] The control module may further be configured for monitoring one or more safety criteria, said safety criteria including at least one of the following: a Thermal Index (TI), a Mechanical Index (MI), or a temperature of said transmitter. The control module may further be configured for adjusting a total transmission power of said one or more transmitters, based on said absorbed power, said implant power and a value of at least one of said safety criteria exceeding a threshold.

[0024] The array of transmitters may be a phased array of transducers, and the amplitude and phase of each of said two or more transmitters may also be controlled based on said total transmission power.

[0025] The energy transfer signal may be an acoustic signal, and the implant receiver may also include at least one transducer, such that the reflection signal may be reflected from said implant transducer. Specifically, the implant transducer may be an ultrasonic transducer and the energy transfer signal may be an acoustic signal.

[0026] In operation, the control module may be configured for adjusting one or more of said transmission parameters based on one or more predefined rules. Specifically, the control module may be configured for employing a reinforcement learning policy for adjusting said one or more transmission parameters.

[0027] In accordance with one design, the control module may be configured for determining an energy transfer policy of said one or more transmitters, said policy determining an amplitude and phase of the transmitted energy transfer signal of each of said one or more transmitters, utilizing a processing circuitry configured to: a. obtain, a multi-stepped simulation within a simulated environment, the simulated environment comprising: (a) a model of the implant transducer, and (b) one or more models of the one or more transmitters, having: (i) an amplitude of the transmitted energy transfer signal, (ii) a phase of the transmitted energy transfer signal, and (iii) a corresponding energy transfer policy; b. execute, the multi-stepped simulation, wherein at each step of the multi-stepped simulation, the multi-stepped simulation: i. senses a state of the implant transducer and of the transmitters, utilizing the models of the simulated environment; ii. allocates, utilizing the state of the implant transducer, of the one or more transmitters, and of the corresponding energy transfer policy, a given amplitude and a given phase for each of the one or more transmitters to be used in a next step of the multi-stepped simulation by the transmitters to transmit the energy transfer signal; iii. calculates an energy delta between a total amount of energy transmitted by the one or more transmitters and the energy transfer energy actually used for energy transfer the implant battery during the current step of the multi-stepped simulation; iv. receives a reward, the reward is energy delta calculated for the current phase of the multi-stepped simulation; and v. makes changes to the corresponding energy transfer policy in accordance with the reward; and c. upon the execution of the multi-stepped simulation meeting a convergence condition at a given step, determine, the energy transfer policy to be the corresponding energy transfer policy at the given step.

[0028] The convergence condition may be that a deviation of an expectation of an accumulated reward for a threshold number of previous steps of the multi-stepped simulation, previous to the given step, is below a first deviation threshold.

[0029] The model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with data taken from a given patient using said implant and transmitters.

[0030] In accordance with one example, the model of the transducer of the implant, and the one or more models of the one or more transmitters may be associated with historical data taken from one or more patients. In accordance with another example, the model of the transducer of the implant, and the one or more models of the one or more transmitters may be associated with simulated data.

[0031] The passive backscatter module may comprise one or more impedance elements, each of said impedance elements having an impedance value. The passive backscatter module may also be configured for performing switching in order to selectively electrically couple at least one impedance element of said impedance elements to said implant transducer for varying a load impedance of the implant, thereby passively causing said reflection signal to be reflected from said implant transducer. Specifically, the at least one impedance element that is electrically coupled to said implant transducer is changed over time.

[0032] In accordance with one variation, the implant may be a rechargeable implant comprising an implant battery which may be rechargeable by the system via said energy transfer signal. In this case, once the battery is at least partially charged, the implant may resume its operation, even when the transmission of energy transfer signal from the system is halted.

[0033] In this case, the implant may comprise a power management unit associated with the implant transducer and the implant battery, said power management unit being configured to regulate a charging of the implant battery.

[0034] Alternatively, the implant may be passively powered, i.e. configured for being operated only when receiving energy transfer signals.

[0035] In either case, said implant may comprise: an electrically powered functional module; at least one implant receiver associated with the functional module, said implant receiver being configured for receiving one or more energy transfer signals from one or more remote transmitters, and converting at least part of said energy transfer signals into an electrical implant signal for powering said implant; and a passive backscatter module associated with said implant receiver and configured, responsive to said implant receiver receiving said energy transfer signals, for passively causing a reflection signal to be reflected from said implant receiver.

[0036] It should be appreciated that in both cases, the entire system, and specifically, the implant transducer may be configured for being completely passive, i.e. drawing no power from the implant. Specifically, for implants employing an implant battery, the backscatter mechanism may be arranged so as not to draw power from the implant battery.

[0037] The implant itself may be a medical implant in which the functional module may be configured for providing some medical function. Examples of such functions may be, but are not limited to, alleviation of pain, nerve stimulation, pacemaker, digestion etc.

[0038] In view of the above, it should be appreciated that the reflection signal produced by the one or more implant transducers is a passive, unmodulated signal, meaning that it meets the following two conditions: i. the power required for producing the reflection signal is not generated by any component associated with the implant, i.e. does not originate internally of the body; and ii. the implant does not contain any communication processors configured for generating a modulated signal. Instead, the reflected signal is simply a passive reflection resulting in the one or more transducers receiving the energy transfer signal (or portion thereof).

[0039] In accordance with another aspect of the subject matter of the present application, there is provided an implant configured for being powered by a remote transmitter, said implant comprising: an electrically powered functional module; at least one implant receiver associated with the functional module, said implant receiver being configured for receiving one or more energy transfer signals from said remote transmitter, and converting at least part of said energy transfer signals into an electrical implant signal for powering said implant, wherein said energy transfer signals are not modulated with data; and a passive backscatter module associated with said implant receiver and configured, responsive to said implant receiver receiving said energy transfer signals, for passively causing a reflection signal to be reflected from said implant receiver.

[0040] In accordance with still another aspect of the subject matter of the present application there is provided a transmission arrangement configured for transferring energy to an implant, the transmission arrangement comprising: one or more transmitters configured to transmit one or more corresponding energy transfer signals to the implant; a monitoring unit configured for receiving reflection signal generated by the implant; and a control module associated with said monitoring unit, and configured, based on a reflection power of said received reflection signal, to control transmission parameters of said transmitters.

[0041] In accordance with yet a further aspect of the subject matter of the present application, there is provided a method for transferring energy to an implant using the system of the previous aspects of the present application, said method comprising the steps of: • transmitting one or more energy transfer signals from said one or more transmitters towards said implant;

[0042] • receiving said energy transfer signals, by said implant receiver;

[0043] • converting at least part of said energy transfer signals into an electrical implant signal, by said implant receiver, for powering said implant, wherein a reflection signal is reflected from said implant receiver responsive to said implant receiver receiving said energy transfer signals;

[0044] • receiving said reflection signal by said monitoring unit;

[0045] • determining a reflection power of said reflection signal received by said monitoring unit;

[0046] • determining, by said control module, based on said reflection power, whether to adjust one or more transmission parameters of said transmitter; and

[0047] • upon determining that the transmission parameters are to be adjusted, adjusting, by said control module, the transmission parameters.

[0048] In operation, the transmission arrangement may be positioned externally on the skin of a patient, at a location corresponding to the internal position of the implant. The control module may then instruct the one or more transmitters to generate a weak energy transfer signal prompting the passive backscatter module to commence it operation, and thereafter, instruct the one or more transmitter to begin transmitting a strong energy transfer signal configured for operating the implant or powering it.

[0049] In accordance with yet another aspect of the subject matter of the present application, there is provided a flexible patch for providing power to an implant, said flexible patch comprising at least one transmitter configured for transmitting an energy transfer signal to an implant comprising an implant transducer, to thereby power the implant, and associated with at least one monitoring unit configured for receiving a reflection signal from said implant, wherein said flexible patch further comprises a socket for detachable connection to a power source for providing power to said transmitter and said monitoring unit.

[0050] The flexible patch may be designed such that it power may be provided towards: (a) directly powering an electrical module of the implant and / or (b) charging a power source providing power to said electrical module. The flexible patch may further comprise a control module configured for assessment of medium loss of said energy transfer signal to said receiver component to thereby monitor the power level of said implant battery during charging.

[0051] Additionally, the flexible patch may comprise a location indicator configured for assisting the user in determining the correct placement of the patch with respect to the implant.

[0052] The flexible patch may be configured for connection to an external power source. In accordance with one example, the patch may comprise both the transmitters, the control module, and the monitoring unit, while according to another example, the patch may comprise only the transmitters, while the control module and monitoring unit constitute part of an external device configured for connection to the flexible patch. Alternatively, the patch may be provided with a socket configured for receiving therein a power source in the form of a battery. In either case, the patch may be completely disposable, wherein the power sourced is kept while the flexible patch is discarded.

[0053] The flexible patch may be configured for conforming its shape to a surface on which it is placed. Specifically, the flexible patch may comprise an attachment layer configured for fitting said patch to a patient. The attachment layer may be provided with a removable protective cover layer preventing said attachment prior to removal.

[0054] The flexible patch may comprise at least one layered portion comprising layers having high acoustic impedance properties, interlaced with layers having low acoustic impedance properties. Specifically, the layers may be chosen such that the overall acoustic impedance of said layered portion matches a natural acoustic impedance of the patient, the layered portion also comprise at least one piezoelectric layer, and at least one electrode printed on a flexible material.

[0055] In operation, the flexible patch may be applied to the patient using the following steps: a. attaching the flexible patch to a power source to begin generating an energy transfer signal; b. placing the flexible patch on a patient until indication of proper location is provided; c. marking the location; d. removing the protective layer; and e. fixing the patch to the patient.

[0056] In accordance with still another aspect of the subject matter of the present application, there is provided a flexible patch configured for generating a focused energy transfer signal, said patch comprising: at least one layered portion comprising layers of layers having high acoustic impedance properties, interlaced with layers having low acoustic impedance properties; at least one transmitter electrode printed on a flexible layer; at least one piezoelectric layer; and at least one electrical contact for the connection of a power source.

[0057] In accordance with yet another aspect of the subject matter of the present application, there is provided a system for determining an energy transfer policy of one or more transmitters configured for transmitting an energy transfer signal to an implant transducer in order to remotely power an implant, said policy determining an amplitude and phase of the transmitted energy transfer signal of each of said one or more transmitters, the system comprising a processing circuitry configured to: a. obtain, a multi-stepped simulation within a simulated environment, the simulated environment comprising: (a) a model of the implant transducer, and (b) one or more models of the one or more transmitters, having: (i) an amplitude of the transmitted energy transfer signal, (ii) a phase of the transmitted energy transfer signal, and (iii) a corresponding energy transfer policy; b. execute, the multi-stepped simulation, wherein at each step of the multi-stepped simulation, the multi-stepped simulation: i. senses a state of the implant transducer and of the transmitters, utilizing the models of the simulated environment; ii. allocates, utilizing the state of the implant transducer, of the one or more transmitters, and of the corresponding energy transfer policy, a given amplitude and a given phase for each of the one or more transmitters to be used in a next step of the multi-stepped simulation by the transmitters to transmit the energy transfer signal, iii. calculates an energy delta between a total amount of energy transmitted by the one or more transmitters and the energy actually used for powering the implant during the current step of the multi-stepped simulation, iv. receives a reward, the reward is energy delta calculated for the current phase of the multi-stepped simulation, and v. makes changes to the corresponding energy transfer policy in accordance with the reward; and c. upon the execution of the multi-stepped simulation meeting a convergence condition at a given step, determine, the energy transfer policy to be the corresponding energy transfer policy at the given step.

[0058] BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to understand the presently disclosed subject matter and to see how it may be carried out in practice, the subj ect matter will now be described, by way of non-limiting examples only, with reference to the accompanying drawings. The dimensions of components and features shown in the drawings are chosen for convenience and clarity of presentation and are not necessarily to scale. In the drawings:

[0060] Fig- 1 is a schematic illustration of a system for transferring energy to an implant, in accordance with one example of the disclosed subject matter;

[0061] Fig- 2 is a schematic illustration of an implant used in the system shown in Fig. 1;

[0062] Fig- 3 is a block diagram of the system shown in Figs. 1 and 2;

[0063] Fig. 4 is a block diagram of one example of an implant used in the system shown in Figs. 1 to 3;

[0064] Fig. 5 is a flowchart illustrating one example of a sequence of operations for transferring energy using the system shown in Figs. 1 to 4;

[0065] Fig. 6 is a schematic isometric illustration of a system for transferring energy to an implant, in accordance with another example of the disclosed subject matter;

[0066] Fig. 7A is a schematic isometric illustration of a wire powered flexible patch, in accordance with another example of the disclosed subject matter;

[0067] Fig. 7B is a schematic isometric illustration of a battery powered flexible patch, in accordance with another example of the disclosed subject matter; Fig. 7C is a schematic isometric illustration of another example of a wire powered flexible patch, in accordance with another example of the disclosed subject matter;

[0068] Fig. 7D is a schematic isometric illustration of attachment layers of a flexible patch, in accordance with another example of the disclosed subject matter;

[0069] Figs. 8A to 8D are schematic isometric illustrations of the steps of fitting a flexible patch onto a patient’s skin, in accordance with one example of the disclosed subject matter;

[0070] Fig. 9A is a schematic isometric illustration of a transmitter substrate used in the flexible patch, in accordance with one example of the disclosed subject matter;

[0071] Fig. 9B is a schematic isometric exploded isometric view detailing the layers of the substrate shown in Fig. 9A; and

[0072] Fig. 10 is an exemplary flowchart illustrating one example of a sequence of operations carried out for determining a transmission policy for remotely powering or charging an implant, in accordance with the presently disclosed subject matter.

[0073] DETAILED DESCRIPTION

[0074] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the presently disclosed subject matter. However, it will be understood by those skilled in the art that the presently disclosed subject matter may be practiced without these specific details. In other instances, well- known methods, procedures, and components have not been described in detail so as not to obscure the presently disclosed subject matter.

[0075] In the drawings and descriptions set forth, identical reference numerals indicate those components that are common to different embodiments or configurations.

[0076] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “transmitting”, “converting”, “adjusting”, “regulating”, “controlling”, “assessing”, “dividing”, “subtracting” or the like, include actions and / or processes, including, inter alia, actions and / or processes of a computer, that manipulate and / or transform data into other data, said data represented as physical quantities, e.g. such as electronic quantities, and / or said data representing the physical objects. The terms “computer”, “processor”, “processing circuitry” and “controller” should be expansively construed to cover any kind of electronic device with data processing capabilities, including, by way of non-limiting example, a personal desktop / laptop computer, a server (e.g., a cloud computing server), a computing system, a communication device, a smartphone, a tablet computer, a smart television, a processor (e.g. digital signal processor (DSP), a microcontroller, a field- programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc.), a group of multiple physical machines sharing performance of various tasks, virtual servers co-residing on a single physical machine, any other electronic computing device, and / or any combination thereof.

[0077] As used herein, the phrase "for example," "an additional example", "such as", "for instance" and variants thereof describe non-limiting embodiments of the presently disclosed subject matter. Reference in the specification to "one case", "some cases", "other cases" or variants thereof means that a particular feature, structure or characteristic described in connection with the embodiment s) is included in at least one embodiment of the presently disclosed subject matter. Thus, the appearance of the phrase "one case", "some cases", "other cases" or variants thereof does not necessarily refer to the same embodiment(s).

[0078] It is appreciated that, unless specifically stated otherwise, certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

[0079] In embodiments of the presently disclosed subject matter, fewer, more and / or different stages than those shown in Figs. 5 and 10 may be executed. Figs. 1 to 4, 6, 7A to 7D and 9A to 9B illustrate schematics of the architecture of the implant energy transfer system, in accordance with embodiments of the presently disclosed subject matter. Each module in Figs. 1 to 4, 6 and 7A to 7C can be made up of any combination of software, hardware and / or firmware that performs the functions as defined and explained herein. In other embodiments of the presently disclosed subject matter, the system may comprise fewer, more, and / or different modules than those shown in Figs. 1 to 4, 6 and 7A to 7C.

[0080] Any reference in the specification to a method should be applied mutatis mutandis to a system capable of executing the method and should be applied mutatis mutandis to a non-transitory computer readable medium that stores instructions that once executed by a computer result in the execution of the method.

[0081] Any reference in the specification to a system should be applied mutatis mutandis to a method that may be executed by the system and should be applied mutatis mutandis to a non-transitory computer readable medium that stores instructions that may be executed by the system.

[0082] Any reference in the specification to a non-transitory computer readable medium should be applied mutatis mutandis to a system capable of executing the instructions stored in the non-transitory computer readable medium and should be applied mutatis mutandis to method that may be executed by a computer that reads the instructions stored in the non-transitory computer readable medium.

[0083] Attention is first drawn to Figs. 1 and 2, in which an implant energy transfer system is shown, generally designated 1, and comprising an energy transmission module 10, located externally of the body (shown herein as a cross-section of tissue T), and an implant 20, located internally to the body, and configured for being operated or charged by said energy transmission module 10.

[0084] The energy transmission module 10 comprises a control module 14 configured for controlling the transmission signals emitted by a plurality of transmitters 16, arranged in an array R, shown herein to include 15 transmitters in a 3X5 grid, connected to the control module 14 via cables Ci. The transmission module 10 further comprises a monitoring unit 18, configured for receiving signals and providing them back to the control module 14.

[0085] The implant 20 comprises a main body 22 which houses a functional module constituted by a control unit 25 and an electrode 29 extending outside the implant and configured for performing a medical function. Examples of such a function may be alleviation of pain, nerve stimulation, pacemaker etc. The implant 20 further comprises a backscatter mechanism 30, constituted by a receiver 32 and a load 34. All of the components of the implant 20 are powered by a battery 40 connected to the control unit 25 via connections C2, and to the control module 30 via cables C3.

[0086] The transmission module 10 is configured for transmitting, via the transmitters 16, energy transfer signals to the implant 20 across the tissue T and over a distance d between the transmitters 16 and the implant receiver 32 (each of the transmitters 16 transmits an energy transfer signal), wherein a total power of the energy transfer signals is PT. A portion of the power PT in the energy transfer signals is absorbed by the tissue T and surrounding organs (not shown) along a forward path of the energy transfer signals from the transmitters 16 to the implant 20. The energy transfer signals impinge on the implant with a total power Pt= LFPT, where LF represents the forward loss along the forward path. The backscatter mechanism 30 is configured, responsive to the implant receiver 32 receiving the energy transfer signals, for passively causing at least one reflection signal to be reflected from the implant receiver 32 towards the transmission module 10. The reflection signal is reflected from the implant receiver 32 with a power Pt = T(ZL)PI, where T(ZL) is the reflection coefficient of the implant 20, and wherein the reflection coefficient T(ZL) of the implant 20 depends on a load impedance ZL of the implant 20. The reflection signal is then received back at the transmission module 10 by the monitoring unit 18 with a power PR = PrLB, where LB represents the backward loss of the reflection signal along a backward path of the reflection signal from the implant 20 to the transmission module 10. Based on the power of the received reflection signal, the control module 14 is configured for individually controlling transmission parameters of each of the transmitters 16 to transmit additional energy transfer signals towards the implant 20, as detailed further herein, inter alia, with reference to Fig. 5. By controlling the transmission parameters of each of the transmitters 16, control module 14 controls a transmission pattern produced by the transmitter array R.

[0087] In the present disclosure, since the reflection signal that is reflected from the implant receiver 32 towards the transmission module 10 is passively reflected, there is no need for the implant 20 to have a power source and a communication processor for actively generating a reflection signal based on the energy transfer signals. This simplifies the implant 20 in the disclosed energy transfer system 1. The passive reflection of the reflection signal from the implant receiver 32 also allows for a real-time assessment of both the power absorbed in the tissue T and the power delivered to the implant 20, thereby increasing a reliability, safety and efficiency of the energy transfer system 1, as detailed further herein, inter alia with reference to Fig. 5.

[0088] Attention is now drawn to Fig. 3, a block diagram of one example of an implant energy transfer system 100 for transferring energy to an implant 20, in accordance with the presently disclosed subject matter. In accordance with the presently disclosed subject matter, system 100 comprises an energy transmission module 10 and an implant 20. Energy transmission module 10 is configured to include a control module 14, one or more transmitters 16, and a monitoring unit 18.

[0089] The one or more transmitters 16 are configured for concurrently transmitting a corresponding one or more energy transfer signals towards the implant 20. In some cases, energy transmission module 10 includes a single transmitter 16, for example, a single transducer 16’, as illustrated in Fig. 6. In some cases, energy transmission module 10 includes an array of two or more transmitters 16, for example, a phased array R of transducers 16, as illustrated in Fig. 1. In some cases, energy transmission module 10 includes, for the array of transmitters 16, a linear array of transducers.

[0090] In some cases, the one or more energy transfer signals are one or more acoustic signals, i.e., one or more acoustic waves. In some cases, the one or more acoustic signals are one or more ultrasound signals, i.e., one or more ultrasound waves, and the energy transmission module 10 includes a single ultrasound transducer 16 or an array of ultrasound transducers 16.

[0091] Implant 20 is configured to include an electrically powered functional module 125, an implant receiver 32, and a passive backscatter module 135.

[0092] In some cases, implant 120 is a medical implant, and electrically powered functional module 125 is configured for providing a medical function. It is to be noted that the implant 20 can be of any type, including, but not limited to, a neurostimulator, cardiovascular device, or even an artificial organ.

[0093] Implant receiver 32 is associated with, e.g., electrically coupled to, the electrically powered functional module 125, as detailed further herein, inter alia with reference to Fig. 4. Implant receiver 32 is configured for receiving one or more energy transfer signals from the one or more transmitters 16. Implant receiver 32 is further configured for converting at least part of the one or more energy transfer signals into an electrical implant signal for powering the implant 20. That is, implant receiver 32 is configured for harvesting energy from the one or more energy transfer signals for powering the implant 20.

[0094] In some cases, energy transmission module 10 includes a single transducer or an array of transducers. In such cases, implant receiver 32 includes at least one implant transducer 132. In some cases, the at least one implant transducer 132 is a linear array of implant transducers. In cases in which the one or more energy transfer signals are ultrasound signals, the at least one implant transducer 132 is at least one ultrasound transducer.

[0095] Passive backscatter module 135 is associated with the implant receiver 32, as detailed further herein, inter alia, with reference to Fig. 4. It is to be noted that the passive backscatter module 135 is part of the load 34 of the implant 20 (when at least one of the impedance elements (310-a, 310-b, ..., 310-n) of the passive backscatter module 135 is electrically coupled to the implant receiver 32), and that the implant receiver 32 and the load 34 of the implant form a backscatter mechanism 30, as disclosed earlier herein, inter alia with reference to Figs. 1 and 2. Backscatter mechanism 30 is configured, responsive to the implant receiver 32 receiving the one or more energy transfer signals from the energy transmission module 10, for passively causing at least one reflection signal to be reflected from the implant receiver 32 towards the energy transmission module 10. Specifically, passive backscatter module 135 is configured to adjust a load impedance (i.e., an input impedance) of the implant 20 for a fixed period of time in each cycle of the energy transfer signals, as detailed further herein, inter alia with reference to Fig. 4, for passively causing the reflection signal to be reflected from the implant receiver 32 during the fixed period of time.

[0096] Implant 20 is further configured to include a Power management unit (PMU) 140. In some cases, PMU 140 is configured to regulate a distribution of the power in the electrical implant signal to the electrically powered functional module 125. In some cases, implant 20 is configured to include a rechargeable implant battery 40, for powering the implant. In this case, PMU 140 is configured, based on the power in the electrical implant signal (i.e., the energy harvested from the energy transfer signals), to regulate a charging of the implant battery 40.

[0097] Monitoring unit 18 is configured for receiving the at least one reflection signal that is reflected from the implant 20 towards the energy transmission module 10. In some cases, monitoring unit 18 includes a single receiver, for example, a single transducer. For example, if the one or more transmitters 16 are ultrasound transducers, then the monitoring unit 18 also includes at least one ultrasound transducer. In some cases, monitoring unit 18 comprises an array of two or more receivers, including, for example, a phased array of transducers or a linear array of transducers. In some cases, the same transducer or array of transducers is used to both: (a) transmit one or more energy transfer signals from the energy transmission module 10 to the implant 20, and (b) receive at least one reflection signal reflected from the implant 20 towards the energy transmission module 10.

[0098] Control module 14 is configured to include a power detection module 165 and a processing circuitry 180. In some cases, control module 14 is associated with a data repository (not shown), wherein the data repository is optionally distributed.

[0099] Power detection module 165 is configured to detect a power, PR, of the reflection signal that arrives back at the energy transmission module 10 from the implant 20.

[0100] System 100 is configured, e.g., using processing circuitry 180, to control transmission parameters of the one or more transmitters 16. As detailed further herein, inter alia with reference to Fig. 5, the transmission parameters are controlled based on: (a) a power, PR, of the reflection signal that arrives back at the energy transmission module 10 from the implant 20, (b) a power, PT, of the energy transfer signals that are transmitted from the energy transmission module 10 to the implant 20, and (c) an impedance of the load 34 of the implant 20 when the reflection signal is reflected from the implant 20.

[0101] Attention is now drawn to Fig. 4, a block diagram of one example of an implant 20 used in the system 10 shown in Figs. 1 to 3.

[0102] In accordance with the presently disclosed subject matter, implant 20 is configured to include an implant receiver 32. In some cases, implant receiver 32 is configured to include at least one implant transducer 132, as detailed earlier herein, inter alia with reference to Fig. 3.

[0103] Implant receiver 32 is configured to receive one or more energy transfer signals from the energy transmission module 10. Implant receiver 32 also reflects at least one reflection signal towards the energy transmission module 10 in response to receiving the one or more energy transfer signals when the passive backscatter module 135 is associated with (i.e., electrically coupled to) the implant receiver 32. Since a reflection signal is reflected from the implant receiver 32 when the passive backscatter module 135 is associated with the implant receiver 32, some of the power, Pt, of the one or more energy transfer signals that arrive at the implant receiver 32 is not available for powering the implant 20. That is, the power that is available for powering the implant 20 (i.e., the electrical implant signal) when the passive backscatter module 135 is associated with the implant receiver 32 is (approximately) the difference between the power, Pt, of the one or more energy transfer signals that arrive at the implant receiver 32 and the power, Pr, of the reflection signal that is reflected from the implant receiver 32.

[0104] Implant receiver 32 is configured to convert at least part of the energy transfer signals into an electrical implant signal for powering the implant 20. The implant 20 operates in two different states during each cycle of energy transfer signals. During a first time period within each cycle, for example, between 95% and 99% (95%, 96%, 97%, 98%, 99%, etc.) of the cycle, passive backscatter module 135 is not associated with the implant receiver 32. In this case, the load impedance of the implant 20 is (approximately) a designated load impedance for the implant (e.g., 50 Q), and (approximately) all of the power of the energy transfer signals is converted into the electrical implant signal. Moreover, during a remaining time period within each cycle, passive backscatter module 135 is associated with the implant receiver 32. In this case, the load impedance of the implant 20 is changed, and only a part of the power of the energy transfer signals is converted into the electrical implant signal. As a non-limiting example, if the designated load impedance of the implant 20 (i.e., the load impedance of the implant 20 when the passive backscatter module 135 is not associated with the implant receiver 32) is 50 Q, then the load impedance when the passive backscatter module 135 is associated with the implant receiver 32 may be between 10 Q and 40 Q (e.g., 10 Q, 15 Q, 20 Q, 25 Q, 30 Q, 35 Q, 40 Q, etc.).

[0105] In some cases, implant receiver 32 is further configured to include an AC-to-DC converter (not shown in Fig. 4) that converts the AC electrical implant signal into a DC electrical implant signal. The AC-to-DC converter includes a rectifier for converting the AC electrical implant signal into a DC electrical implant signal. In some cases, the AC- to-DC converter further includes a capacitor for smoothing out the DC electrical implant signal.

[0106] Implant 20 is further configured to include an electrically powered functional module 125, as detailed earlier herein, inter alia with reference to Figs. 1 to 3. Implant 20 also is configured to include a power management unit 140. If implant 20 includes an implant battery 40, then the power management unit 140 is configured to regulate the charging of the implant battery 40, and the implant battery 40 is configured to power the electrically powered functional module 125. If implant 20 does not include an implant battery 40, then the power management unit 140 is configured to distribute power to the electrically powered functional module 125.

[0107] Implant 20 is configured to include a passive backscatter module 135. Passive backscatter module 135 is configured to passively cause a reflection signal to be reflected from the implant receiver 32 in response to the implant receiver 32 receiving the one or more energy transfer signals from the energy transmission module 10. Specifically, passive backscatter module 135 is configured for performing switching of switches (e.g., FETs) 315 in order to selectively electrically couple at least one impedance element of one or more impedance elements (310-a, 310-b, . . . , 310-n) to the implant receiver 32 for varying a load impedance of the implant 20, thereby passively causing the reflection signal to be reflected from the implant receiver 32.

[0108] In some cases, the one or more energy transfer signals that are transmitted by the energy transmission module 10 are generated, e.g., using spread spectrum techniques, to control the operation of the passive backscatter module 135, e.g., the switching of the switches 315. Alternatively, in some cases, the operation of the passive backscatter module 135 is predefined in the implant 20. In all cases, the passive backscatter module 135 is entirely powered by the energy transfer signals that are transmitted from the energy transmission module 10 to the implant 20. As a result, the implant 20 does not have to include a power supply and a communication processor for generating a reflection signal to be reflected from the implant 20, but rather the reflection signal is passively reflected from the implant 20. In this manner, the implant 20 can be operated simply, and both the power absorbed by a medium (e.g., tissue T) between the energy transmission module 10 and the implant 20 and the power delivered to the implant 20 can be accurately assessed in real-time, as detailed further herein, inter alia with reference to Fig. 5.

[0109] By assessing the absorbed power and the delivered power in real-time, the reliability and efficiency of the energy transfer system 100 is improved, as detailed further herein, inter alia with reference to Fig. 5. Moreover, in some cases, by assessing the power delivered to the implant 20 over time, the charge level of the implant battery 40, if used, can be determined. Specifically, by monitoring the amount of energy transferred to the battery over the course of operation of the energy transmission module, it may be possible to discern the amount by which the implant battery was charged.

[0110] In an exemplary scenario, a patient may receive an indication (by various means, not related to the system 100) that the battery level of their implant is running low, e.g. at 10%. The patient may then go to charge the implant battery using the system 100. The system 100 may deliver 5W / hr for three hours, for a total of 15W. Using the monitoring unit, the control module 10 calculates that 20% of the energy has been absorbed in the tissue, while 80% has gone towards charging the implant battery. Knowing the implant battery has a capacity of 20W, a simple calculation may yield that the implant battery had 2W prior to charging (10% of 20W), and received 12W (80% of 15W), thus currently being charged at 85%. It should be noted that the figures given in this scenario are also exemplary.

[0111] Passive backscatter module 135 is configured to include one or more impedance elements (310-a, 310-b, ..., 310-n). In some cases, each of the impedance elements has an impedance value that serves as a distinct reference point. By selectively electrically coupling at least one of the impedance elements (310-a, 310-b, . . . , 310-n) to the implant receiver 32 (e.g., including, inter alia, implant transducer 132), an impedance of the load 34 of the implant 20 is adjusted. This results in the reflection signal being reflected from the implant receiver 32. Each of the impedance elements (310-a, 310-b, ..., 310-n) is associated with a switch 315 for electrically coupling the respective impedance element to the implant receiver 32.

[0112] In some cases, system 100 is configured for cycling through the impedance elements (310-a, 310-b, ..., 310-n).

[0113] By cycling through the impedance elements (310-a, 310-b, . . . , 310-n), system 100 is configured to derive a more granular and accurate profile of the electrical properties of the medium (e.g., animal tissue) between the energy transmission module 10 and the implant 20, thereby facilitating a nuanced understanding of the electrical characteristics of the medium. If the medium is animal tissue, the above-mentioned multi-impedance approach allows for a comprehensive assessment, accommodating for the complex and heterogeneous nature of biological tissues. The ability to switch between different impedances and gauge the channel’s response (i.e., the response of the medium) provides a robust mechanism to optimize energy transfer, ensuring efficient operation of the implant 20 while safeguarding the surrounding tissues from potential adverse effects.

[0114] Attention is now drawn to Fig- 5, a flowchart illustrating one example of a sequence of operations 400 for transferring energy using the energy transfer system (1, 1', 100) that is detailed in the present disclosure, inter alia, with reference to Figs. 1 to 4 and 6.

[0115] In accordance with one aspect of the present disclosure, system (1, 1', 100) is configured, e.g., using energy transmission module 10, for transmitting a low power signal (e.g., 10 to 20 pW) to the implant 20 to activate the passive backscatter module 135 (block 404)

[0116] Following the activation of the passive backscatter module 135, system (1, 1', 100) is configured, e.g., using energy transmission module 10, to transmit a cycle of one or more energy transfer signals from a corresponding one or more transmitters 16 towards an implant 20 across a medium (e.g., animal tissue T), for example, as shown in Figs. 1 and 6 (block 408). The one or more transmitters 16 can be a single transmitter or an array of transmitters, for example, a single transducer or a phased array of transducers, as detailed earlier herein, inter alia with reference to Figs. 1 to 3. It is to be noted that the power of the energy transfer signals can be several orders of magnitude greater than the power of the low power signal that is transmitted to activate the passive backscatter module 135.

[0117] The implant receiver 32 of implant 20 is configured to receive the one or more energy transfer signals, wherein at least one reflection signal is reflected from the implant 20 responsive to the implant receiver 32 receiving the one or more energy transfer signals (block 412) The reflection signal is reflected from the implant 20 by adjusting, by passive backscatter module 135, during a part of the cycle, an impedance of a load 34 of the implant 20, as detailed earlier herein, inter alia with reference to Fig. 4. Since the reflection signal is reflected from the implant receiver 32 during a part of the cycle, only a part of the one or more energy transfer signals that is: (i) received by the implant receiver 32 and (ii) not reflected by the implant receiver 32 is converted by the implant receiver 32 into an electrical implant signal for powering the implant 20. This part of the one or more energy transfer signals is referred to below as a remainder of the one or more energy transfer signals received by the implant receiver 32. In some cases, implant receiver 32 includes at least one implant transducer 132, as detailed earlier herein, inter alia with reference to Fig. 3.

[0118] The implant receiver 32 is further configured to convert the remainder of the one or more energy transfer signals received by the implant receiver 32 into an electrical implant signal for powering the implant 20, as detailed earlier herein, inter alia with reference to Fig. 4 (block 416)

[0119] System (1, T, 100) is configured, e.g., using monitoring unit 18, for receiving the reflection signal reflected from the implant receiver 32 towards the energy transmission module 10 (block 420)

[0120] System (1, T, 100) is further configured, e.g., using power detection module 165, for determining a reflection power of the reflection signal (block 424).

[0121] System (1, T, 100) is configured, e.g., using control module 14, for performing, based on the reflection power of the reflection signal and a reflection coefficient of the implant 20, a real-time assessment of a portion of a transmission power of the energy transfer signals that is absorbed in the medium (e.g., animal tissue T) (block 428). This portion of the transmission power is referred to hereinafter as absorbed power. The reflection coefficient T(ZL) of the implant 20 depends on the impedance ZL of the load 34 of the implant 20.

[0122] To explain how the absorbed power is assessed, attention is redrawn to Fig. 1. The total power that is delivered to the implant 20 and absorbed by the medium (e.g., T) is (approximately) the difference between the transmission power, PT, of the energy transfer signals and the reflection power, PR, of the reflection signal that arrives back at the energy transmission module 10. The reflection power, PR, is calculated as follows: PR = PTLBLFF(ZL), wherein Lpis the forward loss of the energy transfer signals between the energy transmission module 10 and the implant 20 (i.e., the percentage of the power of the energy transfer signals that is lost during the propagation of the energy transfer signals between the energy transmission module 10 and the implant 20), and wherein LB is the backward loss of the reflection signal between the implant 20 and the energy transmission module 10 (i.e., the percentage of the power of the reflection signal that is lost during the propagation of the reflection signal between the implant 20 and the energy transmission module 10). Since the total power that is delivered to the implant 20 and absorbed by the medium (e.g., T) is (approximately) the difference between the transmission power, PT, of the energy transfer signals and the reflection power, PR, of the reflection signal that arrives back at the energy transmission module 10, system (1, 1', 100) is configured, e.g., using control module 14, for performing a real-time assessment of the implant power of the electrical implant signal (i.e., the power that is delivered to the implant 20) by subtracting the reflection power, PR, and the absorbed power, AMedium, from the transmission power, PT (block 432).

[0123] System (1, 1', 100) is configured, e.g., using control module 14, to monitor one or more safety criteria that are defined by a safety threshold (block 436). The monitoring of the one or more safety criteria is performed to ensure the safe delivery of the one or more energy transfer signals to the implant 20. Specifically, with regards to the delivery of ultrasonic energy transfer signals, it is recognized that there are potential risks associated with excessive ultrasonic exposure, especially in terms of tissue heating. The monitored safety criteria can include either a Thermal Index (TI) or a Mechanical Index (MI) for diagnostic ultrasound, which provides an estimate of the potential temperature increase in animal tissue T. To minimize the risk of thermal injury, it’s recommended that the TI should typically not exceed a value of 6.0 for bone-related applications and 2.0 for soft tissues. Additionally, in some cases, the monitored safety criteria include the temperature of the transmitters 16. The temperature of the transmitters 16 is monitored to ensure that it remains within safe operational limits, for example, below 43 °C, to prevent any potential skin bums or discomfort to the patient.

[0124] System (1, T, 100) is configured, e.g., using control module 14, to control transmission parameters of each of the one or more transmitters 16, including, inter alia, an amplitude and phase of each of the transmitter’s 16. The transmission parameters are controlled based on the absorbed power (i.e., the power absorbed in the medium), the implant power (i.e., the power delivered to the implant), and one or more values of one or more safety criteria, including, inter alia, a TI or a MI, and, optionally, a temperature of the transmitters 16.

[0125] That is, system (1, T, 100) is configured, e.g., using control module 14, to determine, based on the absorbed power, the implant power, and one or more values of one or more safety criteria, if one or more of the transmission parameters of the one or more transmitters 16 are to be adjusted (block 440). If system (1, 1', 100) determines, e.g., using control module 14 (e.g., a closed loop control module), that there is no need to update the transmission parameters, system (1, 1', 100) is configured, during a next cycle of the transmission of one or more energy transfer signals, to transmit the energy transfer signals while leaving the transmission parameters unchanged. On the other hand, if system (1, 1', 100) determines, e.g., using control module 14, that one or more transmission parameters of the one or more transmitters 16 are to be adjusted, system (1, 1', 100) is configured, e.g., using control module 14, to adjust the one or more transmission parameters that are to be adjusted (block 444). It is to be noted that blocks 408 - 440 in the flowchart in Fig. 5 are performed for each cycle of the transmission of energy transfer signals.

[0126] System (1, 1', 100) is configured, e.g., using control module 14, to control the amplitude and phase of each of the one or more transmitters 16. If the energy transmission module 10 includes two or more transmitters 16, for example, an array R of phased array transducers 16, as illustrated in Fig. 1, system (1, 1', 100) is configured to control the amplitude and phase of each of the transmitters 16, based on the assessed absorbed power and implant power, to allocate the total power of the transmitted energy transfer signals among the transmitters 16. System (1, 1', 100) is configured to allocate the total power of the transmitted energy transfer signals among the transmitters 16 (i.e., carry out a policy), based on the assessed absorbed power and implant power, to efficiently transfer energy to the implant 20, and thereby minimize the absorbed power. For example, system (1, 1', 100) may not allocate power to one of the transmitters 16 in a phase array R of transmitters 16 if the electrical transfer signal from the respective transmitter 16 is to encounter a bone in the human body.

[0127] It is to be noted, more generally, that each of the transmitters 16 in a phased array R of transmitters 16 is provided with an amplitude and a phase to optimize the power efficiency of the communications link between the energy transmission module 10 and the implant 20. Put differently, by controlling the amplitude and the phase of each of the transmitters 16, the phased array R of transmitters 16 allows for focusing the energy transfer signals towards the implant 20 in a manner similar to a lens or a phased array of antennas to optimize the power efficiency of the communications link. To make things clear, the allocation of the amplitude and phase to each of the transmitters 16 in an array R of transmitters 16, provided a given value for the total power of the energy transfer signals, is determined, based on the power absorbed in the medium (e.g., tissue T) and the power delivered to the implant 20, in order to optimize the efficiency of the power transfer. The given value for the total power of the energy transfer signals is dynamically determined, based on the absorbed power in the medium, the delivered power to the implant, and at least one of the safety criteria, to ensure that the power absorbed in the patient's tissue stays within safe limits while the implant gets sufficient power to power the implant 20. All of this is done in real-time in order to obtain accurate readings of the absorbed power in the medium (e.g., tissue T) and the delivered power to the implant 20, even if changes occur in the communications link between the energy transmission module 10 and the implant 20, such as variations in tissue density or composition or movement of the implant 20. This results in an improved reliability and stability of the energy transfer communication link between the energy transmission module 10 and the implant 20.

[0128] The system (1, T, 100), e.g., using control module 14, is configured to adjust the transmission parameters, as detailed above, using any one of various control systems. The control system in various examples can be rule-based, Al-based, machine learning-based, or a hybrid of rule-based and Al-based approaches. A rule-based control system operates using predefined "if-then" rules. In our patient’s context, it follows specific instructions to adjust the behavior of the system (1, T, 100). For instance, a rule might dictate: "If tissue power absorption exceeds a threshold, reduce transmitted power." This approach ensures consistent and predictable actions throughout its operation.

[0129] In some cases, the control system is a reinforcement learning-based system, as detailed further herein, inter alia with reference to Fig. 10 In some cases, the control system is a deep reinforcement learning-based system that is configured to receive an ultrasound image of the implant 20 created by the array R of transmitters 16 in the energy transmission module 10, the current state of the amplitude and phase for each of the transmitters 16 in the array R, and the power efficiency (the ratio of implant power to absorbed power) achieved by the current state. The control system outputs a new arrangement of amplitudes and phases for the transmitters 16 in the array R, aiming to minimize the loss in the tissue. This control system is responsible for setting the amplitude and phase for each transmitter 16 in the array R, with the primary objective of minimizing the absorbed power in the tissue, improving the efficiency of the energy transfer between the energy transmission module 10 and the implant 20, and transmitting power towards the implant 20, for example, to charge its implant battery 40.

[0130] It is to be noted that, with reference to Fig. 5, some of the blocks can be integrated into a consolidated block or can be broken down to a few blocks and / or other blocks may be added. Furthermore, in some cases, the blocks can be performed in a different order than described herein. It is to be further noted that some of the blocks are optional. It should be also noted that whilst the flow diagrams are described also with reference to the system elements that realizes them, this is by no means binding, and the blocks can be performed by elements other than those described herein.

[0131] With reference to Fig- 6, another example of the system is shown, generally designated 1’, which is essentially identical to the previously disclosed system 1, with one of the differences being that instead of an array R of transmitters 16, the transmission module 10’ comprises only a single transmitter 16’.

[0132] Turning now to Fig. 7A, a flexible patch is shown, generally designated 501, and constituting an energy transmission module 510, having similar working principles as energy transmission module 10 previously described. The flexible patch 501 is configured for being fitted to a patient’s skin (shown Figs. 8A to 8D), at a location corresponding to that of an implant of the patient, and is in the form of a flat flexible surface 502.

[0133] The flexible patch 501 comprises a control module 514 configured for controlling the transmission patterns of an array R of transmitters 516. The flexible patch 501 shown in Fig. 7A is electrically powered by an external power source (not shown) via cable 506. The flexible patch 501 further comprises an adhesive layer 504 configured for securing the patch 501 to the patient, and a protective layer 505, attached over the adhesive layer 504.

[0134] Attention is now drawn to Fig. 7B, in which another example of a flexible patch is shown, generally designated 501’, and differing from the previously described patch 501, in that it is not powered by cable. Instead, the patch 501’ is provided with a battery port 530 configured for removably receiving therein a designated battery 540 (shown in Figs. 8A to 8D) powering the patch 501’ via contacts 532 and 534. The arrangement shown in system 501’ provides an important advantage, as the flexible patch 501’ may be completely disposable, while the battery 540 may be used for powering a plurality of patches 501’ . Specifically, once the procedure involving the patch 501’ is over, the battery 540 can be out of the port 530, the patch 501’ may be disposed of, and the battery 540 may be placed into another patch 501’, and so on, until the battery is depleted.

[0135] In addition, the patch 501 ’ is provided with an indication light 550, configured for indicating to the applicator of the patch 501’ that it is properly placed on the patient’s body. The specific application of the patch 501’ and the use of the indication light 550 will further be discussed with respect to Figs. 8A to 8D.

[0136] With reference to Fig. 7C, another example is shown of a system generally designated 501”, in which the flexible patch is designed to comprise only the transmission array R and a set of contacts 508”, and is configured for being attached to an external unit 601” which includes the control module and monitoring unit (not shown).

[0137] It will be appreciated that this configuration allows for the manufacturing of an extremely simply and cheap patch, wherein the majority of complicated (and costly) functional components such as circuit boards are contained within the external unit 601”. In this way, it becomes even more efficient and cost effective for the flexible patch 501” to be a single-use item, while the external unit 601” is reusable.

[0138] The unit 601” may comprise a screen configured for displaying various forms of data regarding the transmission of the energy transfer signals.

[0139] Turning now to Fig. 7D, the layered structure of the patch 501’ is shown, comprising the main body 502, an adhesive layer 504 configured for properly attaching the patch 501’ to the patient’s body, and a removable protective layer 505, covering the adhesive side of the adhesive layer 504. As will be shown in Figs. 8A to 8D, this protective layer 505 has to be removed from the patch 501’, before applying the patch 501’ to the patient’s skin.

[0140] Attention is now drawn to Figs. 8A to 8D, in which a schematic representation of steps of applying the patch to the patient are shown as follows:

[0141] Fig. 8A shows a preliminary step before applying the patch 501’. A battery 540 is inserted into the port 530 of the patch 501’ in order to power it. Once the patch is powered, the transmission module 510 begins transmitting energy transfer signals to the implant 20. The patch 501’ is then placed on the patient’s skin S, at an estimated location corresponding to the implant. The patch 501’ is then moved around (arrows r), and based on a monitoring unit 518 (not shown), the control module 514 is able to determine the optimal location for performing the energy transfer to the implant 20. This action is performed with the protective layer 505 still on.

[0142] Fig. 8B shows a state where the optimal location has been determined. At this point, the control module 510 sends a signal to the indication light 550 to turn on, indicating to the user that the optimal location has been achieved.

[0143] Fig. 8C shows the next step in which the patch 501’ is slightly lifted above the optimal location allowing for the peeling off of the protective layer 505 (in the direction of arrow P).

[0144] Fig. 8D shows the final step in which the patch 501’ is placed back on the patient’s skin S, such that the adhesive layer 504 firmly attaches the patch 501’ to the optimal location for the remainder of the procedure. Prior to this step, a gel may be applied to the patient’s skin, similar to that used in ultrasound examinations, configured for preventing loss of energy during transmission of the energy transfer signals from the patch to the implant.

[0145] Once the procedure is over, the battery 540 is pulled out of the port 530, the patch 501’ is peeled from the patient’s skin S and discarded (being disposable).

[0146] Attention is now drawn to Figs. 9A and 9B, in which a transmission unit of the patch 501 is shown, having an array R of transmitters 516, fitted with a layered structure 560 configured for performing acoustic impedance matching. Specifically, the layered structure 560 comprises a set of alternating layers of high acoustic impedance materials 562 and low acoustic impedance materials 564. The design is such that the arrangement of the layers 562 and 564 is configured for matching the acoustic impedance of the energy transfer signal passed therethrough from the transmitters 516 to that of the human tissue T, thereby reducing energy reflections and losses. The alternating layers may be made, for example, from: High acoustic impedance materials, typically of over the acoustic impedance of the PZT ceramic (30MRayl), such as gold (63.8MRayl) and steel (45MRayl) with low acoustic impedance materials such as parylene (2.58MRayl) and epoxy (3.05MRayl). By utilizing this structure, a thin device can be easily achieved. The materials can be applied to the patch using standard coating methods such as physical vapor deposition. The patch itself, with its interconnects, can be made of materials such as mylar, polyimide, PEEK or transparent conductive polyester film, printed with copper traces in standard PCB techniques.

[0147] Fig. 10 is an exemplary flowchart illustrating one example of a sequence of operations carried out for determining a policy for remotely powering or charging an implant, in accordance with the presently disclosed subject matter.

[0148] According to certain examples of the presently disclosed subject matter, an energy transmission module 10 for determining a policy for remotely powering or charging an implant can be configured to perform a policy determination process 700, e.g., utilizing a policy determination module.

[0149] An implant of a patient can be operated or charged remotely, for example, by utilizing one or more transmitters 16 that are located on a body of the patient. The transmitters 16 emit energy transfer signals that can operate or recharge the implant. The energy transfer signals are dependent on the amplitude and phase of the one or more transmitters 16 and on the pattern in which these transmitters are employed to transmit their corresponding energy transfer signals. The policy that is utilized to decide which transmitters of the transmitters 16 are utilized and how they are employed - which amplitude and phase of the transmitted signal are utilized for each of the transmitters 16 can be determined automatically using a reinforcement learning machine learning technique.

[0150] This policy may be based on at least two parameters: a first amount of power defining the power of the one or more energy transfer signals to an implant receiver 32 of the implant 20, and a second amount of power, defining the amount of power actually received by the implant, thereby being able to decide on an amplitude and phase of the energy transfer signals in the next transmission.

[0151] For this purpose, the energy transmission module 10 can be configured to obtain, a multi-stepped simulation within a simulated environment, the simulated environment comprising: (a) a model of the implant receiver 32 of the implant 20, and (b) one or more models of the one or more transmitters 16, having: (i) a spatial location, (ii) an amplitude of the energy transfer signal, (iii) a phase of the energy transfer signal, and (iv) a corresponding policy (block 710). After obtaining the multi-stepped simulation, the energy transmission module 10 is further configured to execute the multi-stepped simulation, wherein at each step of the multi-stepped simulation, the multi-stepped simulation: (a) senses a state of the transducer of the implant and of the transmitters, utilizing the models of the simulated environment, (b) allocates, utilizing the state of transducer of the implant and of the transmitters and the corresponding energy transfer policy, a given amplitude and a given phase for each of the transmitters to be used in a next step of the multi-stepped simulation by the transmitters to transmit the energy transfer signal, (c) calculates an energy delta between a total amount of energy transmitted by the transmitters, being the sum of the first amounts of energy transfer power transmitted by the transmitters during the current step of the multi-stepped simulation and the second amount of energy transfer power that actually powered or charged the implant during the current step of the multi-stepped simulation, (d) receives a reward, the reward is energy delta calculated for the current phase of the multi-stepped simulation, and (e) makes changes to the corresponding energy transfer policy in accordance with the reward (block 720).

[0152] In some cases, the model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with data taken from a given patient using said implant and transmitters. In other cases, the model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with historical data taken from one or more patients. It can also be that the model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with simulated data, for example, simulated based on historical information.

[0153] Upon the execution of the multi-stepped simulation meeting a convergence condition at a given step, determine, the energy transfer policy to be the corresponding energy transfer policy at the given step (block 730). In some cases, the convergence condition is that a deviation of an expectation of an accumulated reward for a threshold number of previous steps of the multi-stepped simulation, previous to the given step, is below a first deviation threshold.

[0154] A system for remotely energy transfer an implant allowing one or more transmitters connected to a power source and configured to transmit an energy transfer signal associated with a first amount of energy transfer power to an transducer of the implant, thereby energy transfer the implant by a second amount of energy transfer power, to decide on an amplitude and phase of the transmitted energy transfer signal, wherein at least emitter if the transmitters utilizes the energy transfer policy described above to decide on a given amplitude and on a given phase of the transmitted energy transfer signal. The energy transfer policy can determine the pattern of transmitters used by the system when energy transfer the implant.

[0155] It is to be understood that the presently disclosed subject matter is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The presently disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways. Hence, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present presently disclosed subject matter.

[0156] It will also be understood that the system according to the presently disclosed subject matter can be implemented, at least partly, as a suitably programmed computer. Likewise, the presently disclosed subject matter contemplates a computer program being readable by a computer for executing the disclosed method. The presently disclosed subject matter further contemplates a machine-readable memory tangibly embodying a program of instructions executable by the machine for executing the disclosed method.

[0157] Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations, and modifications can be made without departing from the scope of the invention, mutatis mutandis

Claims

CLAIMS:

1. An implant energy transfer system, the system comprising: an implant comprising: o an electrically powered functional module; o an implant receiver associated with the functional module, said implant receiver being configured for receiving one or more energy transfer signals, and converting at least part of said energy transfer signals into an electrical implant signal for powering said implant; and o a passive backscatter module associated with said implant receiver, said passive backscatter module being configured, responsive to said implant receiver receiving said energy transfer signals, for passively causing at least one reflection signal to be reflected from said implant receiver; an energy transmission module comprising: o one or more transmitters configured to transmit said one or more energy transfer signals to the implant; o a monitoring unit configured for receiving said reflection signal; and a control module associated with said monitoring unit, and configured, based on a reflection power of said received reflection signal, to control transmission parameters of said transmitters.

2. A system according to Claim 1, wherein said energy transfer signals are transmitted through a medium towards said implant; and wherein said control module is configured, for calculating at least one of the following: (a) the power absorbed in the medium, (b) the reflection power of the received reflection signal, and (c) the power absorbed in the implant.

3. A system according to Claim 1 or 2, wherein said control module is configured to calculate the implant power of the electrical implant signal.

4. A system according to Claim 3, wherein said one or more transmitters is a single transmitter; and wherein said transmission parameters, being transmission parameters of said transmitter, are controlled based on said absorbed power and said implant power.

5. A system as defined in Claim 4, wherein said transmission parameters include at least one of an amplitude or a phase.

6. A system according to Claim 4 or 5, wherein said transmitter is a single-element transducer; wherein said implant receiver includes at least one implant transducer; and wherein said reflection signal is reflected from said implant transducer.

7. A system according to Claim 3, wherein said one or more transmitters is an array of two or more transmitters; and wherein, for each respective transmitter of said two or more transmitters, said control module is configured, based on said absorbed power and said implant power, to control given parameters of said transmission parameters, said given parameters including an amplitude and a phase of said respective transmitter.

8. A system according to Claim 3, wherein said control module is further configured for: monitoring one or more safety criteria, said safety criteria including at least one of the following: a Thermal Index (TI), a Mechanical Index (MI), or a temperature of said transmitter; and adjusting a total transmission power of said one or more transmitters, based on said absorbed power, said implant power and a value of at least one of said safety criteria exceeding a threshold.

9. A system according to claim 7, wherein said array of two or more transmitters is an array of transducers; wherein said implant receiver includes at least one implant transducer; and wherein said reflection signal is reflected from said implant transducer.

10. A system according to claim 9, wherein said array of transducers is a phased array of transducers.

11. A system according to any one of Claim 6, 9 or 10, wherein said energy transfer signal is an acoustic signal.

12. A system according to Claim 11, wherein said implant transducer is an ultrasonic transducer, and wherein said acoustic signal is an ultrasound signal.

13. A system according to any one of Claims 2 to 12, wherein said medium is animal tissue.

14. A system according to any one of Claims 1 to 13, wherein said passive backscatter module comprises one or more impedance elements, each of said impedance elements having an impedance value.

15. A system according to Claim 14, wherein said passive backscatter module is configured for performing switching in order to selectively electrically couple at least oneimpedance element of said impedance elements to said implant receiver for varying a load impedance of the implant, thereby passively causing said reflection signal to be reflected from said implant receiver.

16. A system according to Claim 15, wherein said at least one impedance element that is electrically coupled to said implant transducer is changed over time.

17. A system according to any one of Claims 1 to 16, wherein said control module is configured to adjust one or more of said transmission parameters based on one or more predefined rules.

18. A system according to any one of Claims 1 to 17, wherein said control module is configured for employing a reinforcement learning policy for adjusting said one or more transmission parameters.

19. The system according to any one of Claims 1 to 18, wherein said functional module is configured for providing a medical function.

20. The system according to any one of claims 1 to 19, wherein the implant further comprises: an implant battery configured for powering said functional module; and a power management unit associated with the implant transducer and the implant battery, said power management unit being configured to regulate a charging of the implant battery.

21. An implant configured for being powered by one or more remote transmitters, said implant comprising: an electrically powered functional module; at least one implant receiver associated with the functional module, said implant receiver being configured for receiving one or more energy transfer signals from said one or more remote transmitters, and converting at least part of said energy transfer signals into an electrical implant signal for powering said implant; and a passive backscatter module associated with said implant receiver and configured, responsive to said implant receiver receiving said energy transfer signals, for passively causing a reflection signal to be reflected from said implant receiver.

22. An energy transmission module comprising:o one or more transmitters configured to transmit one or more corresponding energy transfer signals to an implant; o a monitoring unit configured for receiving a reflection signal from said implant; and o a control module associated with said monitoring unit, and configured, based on a reflection power of said received reflection signal, to control transmission parameters of said transmitters23. A method for transferring energy to an implant using the system of any one of Claims 1 to 20, said method comprising the steps of• transmitting one or more energy transfer signals from said one or more transmitters towards said implant;• receiving said energy transfer signals, by said implant receiver;• converting at least part of said energy transfer signals into an electrical implant signal, by said implant receiver, for powering said implant, wherein a reflection signal is reflected from said implant receiver responsive to said implant receiver receiving said energy transfer signals;• receiving said reflection signal by said monitoring unit;• determining a reflection power of said reflection signal received by said monitoring unit;• determining, by said control module, based on said reflection power, whether to adjust one or more transmission parameters of said transmitter; and• upon determining that the transmission parameters are to be adjusted, adjusting, by said control module, the transmission parameters.

24. A flexible patch for providing power to an implant, said flexible patch comprising at least one transmitter configured for transmitting an energy transfer signal to an implant comprising an implant transducer, to thereby power the implant, and associated with at least one monitoring unit configured for receiving a reflection signal from said implant, wherein said flexible patch further comprises a socket for detachable connection to a power source for providing power to said transmitter and said monitoring unit.

25. A flexible patch according to Claim 24, wherein said power may be provided towards: (a) directly powering an electrical module of the implant and / or (b) charging a power source providing power to said electrical module.

26. A flexible patch according to Claim 24 or 25, wherein said patch further comprises a control module configured for assessment of medium loss of said energy transfer signal to said receiver component to thereby monitor the power level of said implant battery during charging.

27. A flexible patch according to Claim 24, 25 or 26, wherein said patch comprises a location indicator configured for assisting the user in determining the correct placement of the patch with respect to the implant.

28. A flexible patch according to any one of Claims 24 to 27, wherein said patch is disposable.

29. A flexible patch according to any one of Claims 24 to 28, wherein said socket is configured for removably receiving therein a battery.

30. A flexible patch according to any one of Claims 24 to 29, wherein said patch is configured to conform its shape to a surface on which it is placed.

31. A flexible patch according to any one of Claims 24 to 30, wherein said patch comprises an attachment layer configured for fitting said patch to a patient.

32. A flexible patch according to Claim 30, wherein said attachment layer is provided with a removable protective layer preventing said attachment.

33. A flexible patch according to any one of Claims 24 to 32, wherein said patch comprises at least one layered portion comprising layers having high acoustic impedance properties, interlaced with layers having low acoustic impedance properties.

34. A flexible patch according to Claim 33, wherein said layers are chosen such that the overall acoustic impedance of said layered portion matches a natural acoustic impedance of the patient.

35. A flexible patch according to Claim 33 or 34, wherein said layered portion comprises at least one piezoelectric layer, and at least one electrode printed on a flexible material.

36. A method for powering an implant using the flexible patch of any one of Claims 24 to 35, said method comprising the steps of:f. Attaching the flexible patch to a power source to begin generating an energy transfer signal; g. placing the flexible patch on a patient until indication of proper location is provided; h. marking the location; i. removing the protective layer; and j . fixing the patch to the patient.

37. A flexible patch configured for generating a focused energy transfer signal, said patch comprising: at least one layered portion comprising layers of layers having high acoustic impedance properties, interlaced with layers having low acoustic impedance properties; at least one transmitter electrode printed on a flexible layer; at least one piezoelectric layer; and at least one electrical contact for the connection of a power source.

38. A flexible patch according to Claim 37, wherein said at least one piezoelectric layer is constituted by a piezoceramic resonator.

39. A system for determining an energy transfer policy of one or more transmitters configured for transmitting an energy transfer signal to an implant transducer in order to remotely power an implant, said policy determining an amplitude and phase of the transmitted energy transfer signal of each of said one or more transmitters, the system comprising a processing circuitry configured to: d. obtain, a multi-stepped simulation within a simulated environment, the simulated environment comprising: (a) a model of the implant transducer, and (b) one or more models of the one or more transmitters, having: (i) an amplitude of the transmitted energy transfer signal, (ii) a phase of the transmitted energy transfer signal, and (iii) a corresponding energy transfer policy; e. execute, the multi-stepped simulation, wherein at each step of the multi-stepped simulation, the multi-stepped simulation: i. senses a state of the implant transducer and of the transmitters, utilizing the models of the simulated environment;ii. allocates, utilizing the state of the implant transducer, of the one or more transmitters, and of the corresponding energy transfer policy, a given amplitude and a given phase for each of the one or more transmitters to be used in a next step of the multistepped simulation by the transmitters to transmit the energy transfer signal, iii. calculates an energy delta between a total amount of energy transmitted by the one or more transmitters and the energy transfer energy actually used for energy transfer the implant battery during the current step of the multi-stepped simulation, iv. receives a reward, the reward is energy delta calculated for the current phase of the multi-stepped simulation, and v. makes changes to the corresponding energy transfer policy in accordance with the reward; and f. upon the execution of the multi-stepped simulation meeting a convergence condition at a given step, determine, the energy transfer policy to be the corresponding energy transfer policy at the given step.

40. A system of claim 38, wherein the convergence condition is that a deviation of an expectation of an accumulated reward for a threshold number of previous steps of the multi-stepped simulation, previous to the given step, is below a first deviation threshold.

41. A system of Claim 38 or 39, wherein the model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with data taken from a given patient using said implant and transmitters.

42. A system for determining a energy transfer policy according to Claim 38, 39 or 40, wherein the model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with historical data taken from one or more patients.

43. A system for determining a energy transfer policy according to any one of Claims 38 to 41, wherein the model of the transducer of the implant, and the one or more models of the one or more transmitters are associated with simulated data.

44. A system for remotely powering or charging an implant battery allowing one or more transmitters connected to a power source and configured to transmit one or more energy transfer signals associated with a first amount of power to an transducer of the implant, thereby powering or charging the implant by a second amount of power, to decide on an amplitude and phase of the transmitted energy transfer signals, wherein atleast one transmitter of the transmitters utilizes the power transfer policy of claim 40 to decide on a given amplitude and on a given phase of the transmitted energy transfer signal.

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