Implantable medical device and wireless energy transmission method

Abstract

The present application provides an implantable medical device and a wireless energy transmission method, wherein the receiving coil of the implantable medical device outputs an AC voltage, the rectifier circuit converts the AC voltage into a DC voltage, the electrical stimulation module has a first working state and a second working state, and the load balancing circuit controls the controllable load to access the output end of the rectifier circuit when the electrical stimulation module is in the second working state, and controls the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range. By controlling the controllable load to dynamically access the output end of the rectifier circuit, when the electrical stimulation module switches between the first working state and the second working state, the load change of the implantable medical device is stable, thereby reducing the fluctuation of the reflected impedance of the transmitting end, ensuring that the power amplifier of the transmitting end outputs a stable voltage signal, thereby avoiding the occurrence of erroneous demodulation data output of the implantable medical device based on coil pair coupling communication, and improving the effectiveness and accuracy of communication.

Description

Technical Field

[0001] The present application relates to the technical field of wireless energy transmission, and in particular to an implantable medical device and a wireless energy transmission method. Background Art

[0002] There are two ways to power implantable medical devices: one is battery power, including disposable batteries and rechargeable batteries, and the other is battery-free power. Rechargeable battery and battery-free implantable medical devices often use coil pair coupling to transmit power from the external transmitter to the implant receiving end, which is rectified by the rectifier circuit and supplied to the battery management unit or application circuit. The transmitting coil of the transmitter and the receiving coil of the implantable medical device form a coil pair.

[0003] When the coil pair is used for both wireless energy transmission and communication, the load change of the rectifier circuit of the implantable medical device will affect the communication quality between the coil pairs, especially when pulses are output and when they are not output. For example, when implantable medical devices such as spinal cord nerve stimulators and micro peripheral nerve stimulators output stimulation pulses and when they do not output stimulation pulses, the load after the rectifier circuit is different and is a mutation, thereby affecting the effectiveness and accuracy of communication. Summary of the invention

[0004] In view of this, the present application provides an implantable medical device and a wireless energy transmission method to solve the deficiencies in the related art.

[0005] In a first aspect of the present application, an implantable medical device is provided, comprising:

[0006] The receiving coil is used to receive the energy sent by the sending coil at the sending end and output an AC voltage;

[0007] A rectifier circuit, used for converting the AC voltage into a DC voltage;

[0008] an electrical stimulation module, having a first working state and a second working state, wherein the electrical stimulation module outputs stimulation pulses when in the first working state and does not output stimulation pulses when in the second working state;

[0009] A load balancing circuit is used to control a controllable load to be connected to the DC output end of the rectifier circuit when the electrical stimulation module is in the second working state, and to control the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, and the preset range is determined according to the power consumption of the electrical stimulation module in the first working state.

[0010] According to one embodiment of the present application, the load balancing circuit includes:

[0011] A control unit, configured to generate a control signal according to the working state of the electrical stimulation module;

[0012] A switch circuit, wherein the control end of the switch circuit receives the control signal, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state, so as to connect the controllable load to the DC output end of the rectifier circuit.

[0013] According to one embodiment of the present application, the electrical stimulation module includes a storage unit, and the storage unit is used to store the working parameters of the electrical stimulation module, and the working parameters include the frequency, width and / or amplitude of the stimulation pulse output by the electrical stimulation module;

[0014] The control unit is specifically used for:

[0015] Acquire the operating parameters from the storage unit;

[0016] Determining the working state of the electrical stimulation module according to the working parameters;

[0017] A control signal is generated according to the working state of the electrical stimulation module.

[0018] According to an embodiment of the present application, the control signal includes a pulse width modulation PWM wave, and the switch circuit includes an NMOS tube;

[0019] The NMOS tube is specifically used for:

[0020] The gate of the NMOS tube receives the PWM wave, and the NMOS tube is turned on when the PWM wave is at a high level.

[0021] According to one embodiment of the present application, the controllable load includes at least one of the following: a resistor array, and an energy storage circuit.

[0022] According to one embodiment of the present application, the energy storage circuit includes an adjustable constant current source and an energy storage unit, wherein the adjustable constant current source is used to charge the energy storage unit;

[0023] The load balancing circuit is specifically used for:

[0024] When the electrical stimulation module is in the second working state, controlling the energy storage circuit to be connected to the DC output terminal of the rectifier circuit;

[0025] The output current of the adjustable constant current source is controlled so that the sum of the power consumption of the energy storage circuit and the electrical stimulation module is within the preset range.

[0026] In a second aspect of the present application, a wireless energy transmission method is provided, which is applied to an implantable medical device, wherein the implantable medical device comprises: a receiving coil, a rectifier circuit, an electrical stimulation module, a load balancing circuit and a controllable load, and the method comprises:

[0027] The receiving coil receives energy sent by the sending coil at the sending end and outputs an AC voltage;

[0028] The rectifier circuit converts the AC voltage into a DC voltage;

[0029] The electrical stimulation module has a first working state and a second working state. The electrical stimulation module outputs stimulation pulses when in the first working state, and does not output stimulation pulses when in the second working state.

[0030] When the electrical stimulation module is in the second working state, the load balancing circuit controls the controllable load to be connected to the DC output end of the rectifier circuit, and controls the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, and the preset range is determined according to the power consumption of the electrical stimulation module in the first working state.

[0031] According to one embodiment of the present application, the load balancing circuit includes a control unit and a switch circuit; when the electrical stimulation module is in the second working state, the load balancing circuit controls the controllable load to be connected to the DC output end of the rectifier circuit, including:

[0032] The control unit generates a control signal according to the working state of the electrical stimulation module;

[0033] The control end of the switch circuit receives the control signal, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state, so as to connect the controllable load to the DC output end of the rectifier circuit.

[0034] According to one embodiment of the present application, the electrical stimulation module includes a storage unit, and the storage unit is used to store the working parameters of the electrical stimulation module, and the working parameters include the frequency, width and / or amplitude of the stimulation pulse output by the electrical stimulation module;

[0035] The control unit generates a control signal according to the working state of the electrical stimulation module, including:

[0036] The control unit obtains the operating parameters from the storage unit;

[0037] Determining the working state of the electrical stimulation module according to the working parameters;

[0038] A control signal is generated according to the working state of the electrical stimulation module.

[0039] According to one embodiment of the present application, the control signal includes a pulse width modulation PWM wave, and the switch circuit includes an NMOS tube; the control end of the switch circuit receives the control signal, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state, including:

[0040] The gate of the NMOS tube receives the PWM wave, and the NMOS tube is turned on when the PWM wave is at a high level.

[0041] According to one embodiment of the present application, the controllable load includes at least one of the following: a resistor array, and an energy storage circuit.

[0042] According to one embodiment of the present application, the energy storage circuit includes an adjustable constant current source and an energy storage unit, wherein the adjustable constant current source is used to charge the energy storage unit;

[0043] The controlling the controllable load to be connected to the DC output terminal of the rectifier circuit and controlling the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range includes:

[0044] Controlling the energy storage circuit to be connected to the DC output terminal of the rectifier circuit;

[0045] The output current of the adjustable constant current source is controlled so that the sum of the power consumption of the energy storage circuit and the electrical stimulation module is within the preset range.

[0046] It can be seen from the above technical scheme that the receiving coil of the implantable medical device receives the energy sent by the transmitting coil of the transmitting end and outputs an AC voltage, the rectifier circuit converts the AC voltage into a DC voltage, the electrical stimulation module has a first working state and a second working state, the electrical stimulation module outputs a stimulation pulse when it is in the first working state, and does not output a stimulation pulse when it is in the second working state, and the load balancing circuit controls the controllable load to access the DC output end of the rectifier circuit when the electrical stimulation module is in the second working state, and controls the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, and the preset range is determined according to the power consumption of the electrical stimulation module in the first working state. By controlling the controllable load to dynamically access the DC output end of the rectifier circuit, when the electrical stimulation module switches between the first working state and the second working state, the load change of the implantable medical device is stable, thereby reducing the fluctuation of the reflected impedance of the transmitting end, ensuring that the power amplifier of the transmitting end outputs a stable voltage signal, and thus avoiding the occurrence of erroneous demodulation data output of the implantable medical device based on coil-pair coupling communication, thereby improving the effectiveness and accuracy of communication.

[0047] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a structural schematic diagram of an implantable medical device provided in an embodiment of the present application;

[0049] Figure 2 is a schematic diagram of a stimulation pulse and a control signal provided in an embodiment of the present application;

[0050] Figure 3 This is a schematic diagram of a load balancing principle provided by an embodiment of the present application;

[0051] Figure 4 This is a schematic diagram of a load balancing principle provided by an embodiment of the present application;

[0052] Figure 5 is a structural diagram of an in vitro transmitting end provided in an embodiment of the present application;

[0053] Figure 6 It is a flowchart of a wireless energy transmission method provided in an embodiment of the present application;

[0054] Figure 7 It is a structural schematic diagram of an implantable medical device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0055] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0056] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0057] In order to enable those skilled in the art to better understand the technical solutions provided by the embodiments of the present application and to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings.

[0058] Rechargeable battery and battery-free implantable medical devices often use coil pair coupling to transmit power from the transmitter to the implant receiving end, where the transmitter coil and the receiver coil of the implantable medical device form a coil pair. However, when the coil pair is used for both wireless energy transmission and communication, if the load after the rectifier circuit of the implantable medical device changes significantly, the communication quality between the coil pairs will be affected.

[0059] For example, the implantable medical device includes an electrical stimulation module after the rectifier circuit. When the electrical stimulation module does not output stimulation, the current is 0.1mA, and this current is continuous. When the electrical stimulation module outputs stimulation, the current is 4mA, the pulse width is 1ms, and the cycle is 10ms. In this way, in a 10ms cycle, there is a large current of 1ms and a small current of 9ms. During the 1ms stimulation output period, because a large current needs to pass, the load is in a low resistance state. During the 9ms time when no stimulation output is performed, because the current passing is small, the load is in a high resistance state. That is to say, the load after the rectifier circuit changes significantly within a certain period, and this load change will affect the effectiveness and accuracy of wireless communication based on coil pair coupling of the implantable medical device.

[0060] The voltage fluctuation of the neurostimulator can easily interfere with the output waveform of the electrical stimulation, affecting the therapeutic effect of the electrical stimulation output of the neurostimulator. In addition, the bit errors caused by the reduced accuracy of communication make it impossible to obtain the working status of the neurostimulator in time. For devices implanted in the human body and with high requirements on the accuracy of electrical stimulation, this situation will cause great safety hazards to users.

[0061] In view of this, the embodiment of the present application discloses an implantable medical device, which controls the controllable load to dynamically access the DC output end of the rectifier circuit, so that when the electrical stimulation module switches between outputting stimulation pulses (first working state) and not outputting stimulation pulses (second working state), the power consumption of the implantable medical device is stable, thereby making the load change of the implantable medical device stable, thereby reducing the fluctuation of the reflected impedance of the transmitting end, and ensuring that the power amplifier of the transmitting end outputs a stable voltage signal. Since the power amplifier of the transmitting end can output a stable voltage signal, the DC voltage output by the rectifier circuit of the implantable medical device also tends to be stable, thereby ensuring the therapeutic effect of the electrical stimulation output of the neurostimulator. At the same time, since the power amplifier of the transmitting end can output a stable voltage signal, it is possible to avoid the erroneous demodulation data output of the implantable medical device based on the coil-pair coupling communication, thereby improving the effectiveness and accuracy of the communication. When the effectiveness and accuracy of the communication are improved, the above-mentioned bit error situation can be reduced, and the performance and reliability of the neurostimulator can be improved.

[0062] like Figure 1 As shown, Figure 1 It is a structural schematic diagram of an implantable medical device provided in an embodiment of the present application.

[0063] In the embodiments of the present application, an implantable medical device may be a medical device that is fully or partially inserted into the human body through surgery or other medical means, and is left in the human body for a long time or temporarily after the surgery. The implantable medical device may be used to treat, repair or replace damaged tissues, organs or functions of the human body.

[0064] The embodiments of the present application do not specifically limit the type of implantable medical device, and the implantable medical device includes an electrical stimulation module, which can output stimulation pulses. For example, the implantable medical device may include a neurostimulator (such as a spinal cord neurostimulator, a micro peripheral nerve stimulator, etc.), a cardiac defibrillator, etc.

[0065] like Figure 1 As shown, the implantable medical device may include a receiving coil 110 , a rectifying circuit 120 , an electrical stimulation module 130 and a load balancing circuit 140 .

[0066] The following is a detailed explanation of each part of the implantable medical device.

[0067] 1. The receiving coil 110 is used to receive energy sent by the transmitting coil at the transmitting end and output an AC voltage.

[0068] In an embodiment of the present application, the implantable medical device can perform wireless energy transmission and wireless communication with an external transmitting end based on the coupling of a coil pair, where the coil pair includes a receiving coil 110 of the implantable medical device and a transmitting coil of the transmitting end. The receiving coil 110 can receive energy sent by the transmitting coil of the transmitting end and output an AC voltage.

[0069] Exemplarily, the receiving coil 110 and the transmitting coil of the transmitting end may include a resonant coil, a micro-spiral coil or other customized coils, and the embodiments of the present application do not specifically limit the types of the receiving coil 110 and the transmitting coil of the transmitting end.

[0070] In some embodiments, the transmitting end can apply an AC voltage signal to the transmitting coil. The change in the voltage waveform causes the current in the transmitting coil to change accordingly, and the changing current will generate a changing magnetic field in space. This changing magnetic field can propagate to the surrounding space in the form of electromagnetic waves. The receiving coil 110 senses the change in the magnetic field in the surrounding space and outputs an AC voltage.

[0071] In some embodiments, the implantable medical device also includes a resonant circuit. After the receiving coil 110 receives the energy sent by the transmitting coil at the transmitting end and outputs an AC voltage, the AC voltage is transmitted to the resonant circuit. The resonant circuit can adjust and optimize the frequency of the AC voltage to ensure that it matches the resonant frequency of the receiving coil 110, thereby improving the energy conversion efficiency.

[0072] In some embodiments, the implantable medical device also includes an impedance matching circuit. The AC voltage processed by the resonant circuit will be further transmitted to the impedance matching circuit. The impedance matching circuit can adjust and optimize the impedance characteristics of the circuit to ensure that the input impedance of the implantable medical device matches the characteristic impedance of the transmission line, thereby reducing energy reflection and loss during transmission, thereby further improving the energy conversion efficiency and stability of the overall system.

[0073] 2. The rectifier circuit 120 is used to convert the AC voltage into a DC voltage.

[0074] The rectifier circuit 120 is used to rectify the AC voltage output by the receiving coil 110 , and convert the AC voltage with periodic positive and negative changes into a DC voltage with a single direction.

[0075] Exemplarily, the rectifier circuit 120 may include a half-wave rectifier circuit, a full-wave rectifier circuit (such as a bridge rectifier), etc.

[0076] In some embodiments, the implantable medical device further includes a filter circuit, which can smooth the pulsating DC voltage output by the rectifier circuit 120 and reduce the ripple in the voltage (ie, the AC component in the voltage), thereby providing a more stable DC voltage output.

[0077] In some embodiments, the implantable medical device also includes a power supply network, which may include components such as an energy storage circuit and a power management circuit. The energy storage circuit can be used to store the electrical energy rectified by the rectifier circuit 120, and the power management circuit can be used to monitor and distribute the electrical energy rectified by the rectifier circuit 120.

[0078] 3. The electrical stimulation module 130 has a first working state and a second working state. The electrical stimulation module outputs stimulation pulses when in the first working state, and does not output stimulation pulses when in the second working state.

[0079] In an embodiment of the present application, the electrical stimulation module 130 can operate based on the DC voltage output by the rectifier circuit 120, and the working states of the electrical stimulation module 130 include a first working state and a second working state, wherein the electrical stimulation module 130 outputs stimulation pulses when in the first working state, and the stimulation pulses can stimulate human tissue or the nervous system to achieve the purpose of treatment, rehabilitation or pain relief, etc. The electrical stimulation module 130 does not output stimulation pulses when in the second working state.

[0080] It can be understood that, usually, the electrical stimulation module 130 has low power consumption and a small current passing through it when not outputting stimulation pulses (i.e., the second working state), and exhibits a high-resistance load characteristic; while it has high power consumption and a large current passing through it when outputting stimulation pulses (i.e., the first working state), and exhibits a low-resistance load characteristic. That is to say, changes in the working state of the electrical stimulation module 130 will cause changes in the load after the rectifier circuit 120.

[0081] In some embodiments, the electrical stimulation module 130 includes a storage unit, which is used to store operating parameters of the electrical stimulation module 130, including the frequency, width and / or amplitude of the stimulation pulses output by the electrical stimulation module 130;

[0082] Regarding the working parameters, the working parameters may be preset working parameters, and the preset working parameters may be pre-stored in the storage unit of the electrical stimulation module 130. For example, when the implantable medical device leaves the factory or is initially configured, the preset working parameters are written into the storage unit of the electrical stimulation module 130.

[0083] Alternatively, the working parameter may be a working parameter received by the implantable medical device in real time, and the implantable medical device and the transmitting end may perform wireless communication based on the coupling of the coil pair, so that the implantable medical device may receive the working parameter sent by the transmitting end in real time.

[0084] The operating parameters are used to control specific properties of the stimulation pulses output by the electrical stimulation module 130. Specifically, the operating parameters may include: the frequency, width and / or amplitude of the stimulation pulses.

[0085] The frequency refers to the number of stimulation pulses generated by the electrical stimulation module 130 per unit time, usually in Hertz. For example, if the electrical stimulation module 130 is set to generate 100 stimulation pulses per second, the frequency of the stimulation pulses in the working parameters is 100 Hz.

[0086] Width refers to the length of time each stimulation pulse lasts, usually measured in milliseconds. The width of a stimulation pulse determines how long the stimulation pulse lasts on the target tissue (such as a nerve or muscle).

[0087] Amplitude refers to the intensity of the voltage or current of the stimulation pulse. The amplitude of the stimulation pulse determines the stimulation intensity of the stimulation pulse on the target tissue.

[0088] 4. A load balancing circuit 140 is used to control a controllable load to be connected to the DC output terminal of the rectifier circuit when the electrical stimulation module is in the second working state, and to control the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, and the preset range is determined according to the power consumption of the electrical stimulation module in the first working state.

[0089] In an embodiment of the present application, when the electrical stimulation module 130 does not output a stimulation pulse (i.e., the second working state), the load balancing circuit 140 controls the controllable load to be connected to the DC output end of the rectifier circuit 120, and controls the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module 130 is within a preset range. Therefore, when the electrical stimulation module 130 does not output a stimulation pulse, the implantable medical device can consume the rectified electric energy of the rectifier circuit 120 through the controllable load, thereby ensuring that the load changes of the implantable medical device during the period when no stimulation pulses are output and the period when stimulation pulses are output are stable.

[0090] In some embodiments, when the electrical stimulation module 130 is in the first working state, the load balancing circuit 140 controls the controllable load to not be connected to the DC output end of the rectifier circuit 120 .

[0091] In some embodiments, the controllable load can be controlled according to actual needs, so as to control and adjust the power consumption of the controllable load. The above-mentioned controllable load includes at least one of the following: a resistor array, an energy storage circuit, that is, the controllable load can be a resistor array, an energy storage circuit, or a combination of an energy storage circuit and a resistor array.

[0092] In some embodiments, the load balancing circuit 140 can determine a preset range, which is determined based on the power consumption of the electrical stimulation module 130 in the first working state, and the power consumption of the electrical stimulation module 130 in the first working state can be determined by the working parameters stored in the storage unit of the electrical stimulation module 130.

[0093] For example, the working parameters may include the frequency, width and amplitude of the stimulation pulse. Based on these working parameters, the power consumption of the electrical stimulation module 130 in the first working state can be estimated. After obtaining the power consumption of the electrical stimulation module 130 in the first working state, the load balancing circuit 140 can determine the preset range based on the power consumption value and the preset power consumption fluctuation threshold. For example, the power consumption of the electrical stimulation module 130 in the first working state is 0.2W, and the preset power consumption fluctuation threshold is 0.02W. The preset range can be determined to be greater than or equal to 0.18W and less than or equal to 0.22W.

[0094] In some embodiments, the load balancing circuit 140 may include a control unit and a switch circuit.

[0095] The control unit may generate a control signal according to the working state of the electrical stimulation module 130 and transmit the control signal to the control end of the switch circuit;

[0096] The control end of the switching circuit can receive a control signal from the control unit, and the control signal is used to control the switching circuit to be turned on when the electrical stimulation module 130 is in the second working state, so as to connect the controllable load to the DC output end of the rectifier circuit 120, and to be disconnected when the electrical stimulation module 130 is in the first working state, so as not to connect the controllable load to the DC output end of the rectifier circuit 120.

[0097] Exemplarily, the control unit may include an MCU, digital control logic, etc., and the switch circuit may include an NMOS, a PMOS, an insulated gate bipolar transistor IGBT (Insulated gate bipolar transistor) switch circuit, etc.

[0098] The control unit can generate a control signal according to the working state of the electrical stimulation module 130:

[0099] In some embodiments, the electrical stimulation module 130 may include a storage unit for storing working parameters of the electrical stimulation module 130, including the frequency, width and / or amplitude of the stimulation pulses output by the electrical stimulation module 130. The control unit may obtain the working parameters from the storage unit of the electrical stimulation module 130, determine the working state of the electrical stimulation module 130 according to the working parameters, and generate a control signal according to the working state of the electrical stimulation module 130.

[0100] like Figure 2 As shown, Figure 2 is a schematic diagram of a stimulation pulse and a control signal provided in an embodiment of the present application. The electrical stimulation module 130 can generate the following according to the working parameters in the storage unit: Figure 2 In the stimulation pulse shown, T1 is the time during which the electrical stimulation module 130 outputs the stimulation pulse in one cycle, and T2 is the idle time after the stimulation pulse ends, that is, the time during which the electrical stimulation module 130 does not output the stimulation pulse.

[0101] The control unit can obtain the working parameters from the storage unit of the electrical stimulation module 130, determine the working state of the electrical stimulation module 130 according to the working parameters, and then generate the working state of the electrical stimulation module 130 according to the working state of the electrical stimulation module 130. Figure 2The control signal shown in FIG. 1 has a period that is the same as the period of the stimulation pulse, T1=T3, T2=T4. The control signal is at a low level during the T3 period and at a high level during the T4 period. After receiving the control signal, the control end of the switch circuit is disconnected during the T3 period, that is, disconnected when the electrical stimulation module 130 outputs the stimulation pulse, and the controllable load is not connected to the DC output end of the rectifier circuit 120. The control end is turned on during the T4 period, that is, turned on when the electrical stimulation module 130 does not output the stimulation pulse, so as to connect the controllable load to the DC output end of the rectifier circuit 120.

[0102] The embodiments of the present application do not specifically limit the method by which the control unit generates a control signal according to the working state of the electrical stimulation module 130. For example, in some embodiments, the electrical stimulation module 130 can feedback its current working state information to the control unit through a sensor or a state feedback mechanism (such as a pin level, an interrupt signal, etc.), and the control unit can generate a control signal according to the working state of the electrical stimulation module 130, etc.

[0103] The control end of the switch circuit may receive a control signal from the control unit, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module 130 is in the second working state:

[0104] In some embodiments, the control signal includes a pulse width modulation (PWM) wave, and the switch circuit includes an NMOS tube.

[0105] PWM wave is a periodic signal consisting of a series of high level (usually 1 or logic high) and low level (usually 0 or logic low) pulses.

[0106] The gate of the NMOS tube can receive a PWM wave. The NMOS tube is turned on when the above-mentioned PWM wave is at a high level, so as to connect the controllable load to the DC output terminal of the rectifier circuit 120 when the electrical stimulation module 130 does not output a stimulation pulse. The NMOS tube is cut off when the above-mentioned PWM wave is at a low level, so as not to connect the controllable load to the DC output terminal of the rectifier circuit 120 when the electrical stimulation module 130 outputs a stimulation pulse.

[0107] The embodiments of the present application do not specifically limit the form of the control signal and the switching circuit. For example, the control signal may also include a pulse code modulation PCM (Pulse Code Modulation) wave or other forms of signals with specific timing and duty cycle, and the switching circuit may include other types of switching elements such as PMOS tubes and IGBTs.

[0108] The load balancing circuit 140 may determine a preset range:

[0109] In some embodiments, the control unit can obtain working parameters from the storage unit of the electrical stimulation module 130, determine the power consumption of the electrical stimulation module 130 in the first working state according to the working parameters, and then determine the above-mentioned preset range according to the power consumption of the electrical stimulation module 130 in the first working state.

[0110] In an embodiment of the present application, the receiving coil of the implantable medical device receives the energy sent by the transmitting coil of the transmitting end and outputs an AC voltage, the rectifier circuit converts the AC voltage into a DC voltage, the electrical stimulation module has a first working state and a second working state, the electrical stimulation module outputs a stimulation pulse when in the first working state, and does not output a stimulation pulse when in the second working state, and the load balancing circuit controls the controllable load to access the DC output end of the rectifier circuit when the electrical stimulation module is in the second working state, and controls the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, and the preset range is determined according to the power consumption of the electrical stimulation module in the first working state. By controlling the controllable load to dynamically access the DC output end of the rectifier circuit, when the electrical stimulation module switches between the first working state and the second working state, the load change of the implantable medical device is stable, thereby reducing the fluctuation of the reflected impedance of the transmitting end, ensuring that the power amplifier of the transmitting end outputs a stable voltage signal, and thus avoiding the occurrence of erroneous demodulation data output of the implantable medical device based on coil-pair coupling communication, thereby improving the effectiveness and accuracy of communication.

[0111] In some embodiments, the controllable load may be an energy storage circuit, and the energy storage circuit may include an adjustable constant current source and an energy storage unit, wherein the adjustable constant current source is used to charge the energy storage unit.

[0112] Exemplarily, the energy storage unit includes a capacitor, a battery, etc., which is not specifically limited in the embodiments of the present application.

[0113] In some embodiments, the load balancing circuit 140 may control the energy storage circuit to be connected to the DC output terminal of the rectifier circuit 120 when the electrical stimulation module 130 is in the second working state;

[0114] The output current of the adjustable constant current source is controlled, so that the energy storage unit is charged with the output current of the adjustable constant current source, so that the sum of the power consumption of the energy storage circuit and the electrical stimulation module 130 is within the above-mentioned preset range.

[0115] like Figure 3 As shown, Figure 3 It is a schematic diagram of a load balancing principle provided in an embodiment of the present application, wherein the energy storage circuit includes an adjustable constant current source and an energy storage unit.

[0116] The control unit may generate a control signal according to the working state of the electrical stimulation module 130 and transmit the control signal to the control end of the switch circuit.

[0117] The control end of the switching circuit can receive a control signal from the control unit, and the control signal is used to control the switching circuit to disconnect when the electrical stimulation module 130 outputs a stimulation pulse (i.e., the first working state). When the switching circuit is disconnected, the energy storage circuit as a whole is not connected to the DC output end of the rectifier circuit. At this time, the adjustable constant current source in the energy storage circuit cannot charge the energy storage unit, no current passes through the energy storage circuit, and the energy storage circuit does not consume power.

[0118] The control signal is also used to control the switch circuit to be turned on when the electrical stimulation module 130 does not output a stimulation pulse (i.e., the second working state). When the switch circuit is turned on, the energy storage circuit is connected to the DC output end of the rectifier circuit, and the output current of the adjustable constant current source in the energy storage circuit can be controlled. The output current of the adjustable constant current source is used to charge the energy storage unit, while ensuring that the sum of the power consumption of the energy storage circuit and the electrical stimulation module 130 is within a preset range.

[0119] In an embodiment of the present application, by controlling the energy storage circuit to dynamically connect to the DC output end of the rectifier circuit, when the electrical stimulation module switches between outputting stimulation pulses (i.e., the first working state) and not outputting stimulation pulses (i.e., the second working state), the power consumption of the implantable medical device is stable, thereby making the load change of the implantable medical device stable, thereby reducing the fluctuation of the reflected impedance at the transmitting end, ensuring that the power amplifier at the transmitting end outputs a stable voltage signal, and thereby avoiding erroneous demodulation data output of the implantable medical device based on coil-pair coupling communication, thereby improving the effectiveness and accuracy of communication.

[0120] like Figure 4 As shown, Figure 4 1 is a schematic diagram of a load balancing principle provided by an embodiment of the present application, wherein the energy storage circuit includes an adjustable constant current source and an energy storage unit. The adjustable constant current source can output a current used by the electrical stimulation module 130 for stimulation output and a current used by the energy storage unit for charging.

[0121] The control unit can obtain working parameters from the storage unit of the electrical stimulation module 130, and determine the working state of the electrical stimulation module 130 according to the working parameters. The control unit can generate a first control signal and a second control signal according to the working state of the electrical stimulation module 130, and transmit the first control signal to the control end of the switching circuit, and transmit the second control signal to the control end of the stimulation channel switch.

[0122] In some embodiments, the control end of the stimulation channel switch receives a second control signal from the control unit, and the second control signal is used to control the stimulation channel switch to be turned on when the electrical stimulation module 130 needs to output a stimulation pulse (i.e., the first working state). When the stimulation channel switch is turned on, the adjustable constant current source can output the current used by the electrical stimulation module 130 for stimulation output, so that the electrical stimulation module 130 outputs a stimulation pulse.

[0123] When the stimulation channel switch is turned on, the control end of the switching circuit can receive a first control signal from the control unit. The first control signal is used to control the switching circuit to be disconnected when the electrical stimulation module 130 outputs a stimulation pulse (i.e., the first working state). When the switching circuit is disconnected, the adjustable constant current source in the energy storage circuit cannot charge the energy storage unit, no current passes through the energy storage circuit, and the energy storage circuit does not consume power.

[0124] In some embodiments, the control end of the stimulation channel switch receives a second control signal from the control unit, and the second control signal is used to control the stimulation channel switch to be disconnected when the electrical stimulation module 130 does not need to output a stimulation pulse (i.e., the second working state). When the stimulation channel switch is disconnected, the electrical stimulation module 130 cannot output a stimulation pulse.

[0125] When the stimulation channel switch is disconnected, the control end of the switching circuit receives a first control signal from the control unit, and the first control signal is used to control the switching circuit to be turned on when the electrical stimulation module 130 does not output a stimulation pulse (i.e., the second working state). When the switching circuit is turned on, the output current of the adjustable constant current source in the energy storage circuit can be controlled, and the energy storage unit can be charged using the output current of the adjustable constant current source. At this time, the current output by the adjustable constant current source for charging the energy storage unit can be equal to the current output by the adjustable constant current source for stimulation output by the electrical stimulation module 130, thereby ensuring that the sum of the power consumption of the energy storage circuit (power consumption during charging) and the power consumption during the period when the electrical stimulation module 130 does not output a stimulation pulse is equal to the power consumption during the period when the electrical stimulation module 130 outputs a stimulation pulse.

[0126] In an embodiment of the present application, the control unit in the load balancing circuit can control the stimulation channel switch to be turned on when the electrical stimulation module needs to output a stimulation pulse, and control the energy storage circuit not to be connected to the DC output end of the rectifier circuit, so that the adjustable constant current source in the energy storage circuit cannot charge the energy storage unit according to the working parameters stored in the electrical stimulation module; and control the stimulation channel switch to be turned off when the electrical stimulation module does not need to output a stimulation pulse, and control the energy storage circuit to be connected to the DC output end of the rectifier circuit, and use the output current of the adjustable constant current source to charge the energy storage unit, so that when the electrical stimulation module switches between outputting stimulation pulses (i.e., the first working state) and not outputting stimulation pulses (i.e., the second working state), the current consumed by the implantable medical device remains unchanged, thereby stabilizing the power consumption and load changes of the implantable medical device, thereby reducing the fluctuation of the reflected impedance of the transmitting end, ensuring that the power amplifier of the transmitting end outputs a stable voltage signal, and thereby avoiding the occurrence of erroneous demodulation data output in the implantable medical device based on coil-pair coupling communication, thereby improving the effectiveness and accuracy of communication.

[0127] like Figure 5 As shown, Figure 5 This is a structural schematic diagram of an extracorporeal transmitting end provided in an embodiment of the present application. The extracorporeal transmitting end may include a DC power supply circuit 510, a power amplifier 520, a signal modulation circuit 530, a high-frequency clock circuit 540, a signal demodulation circuit 550, a main control unit 560 and a resonant transmitting coil 570.

[0128] The DC power supply circuit 510 can provide a DC voltage, and the DC voltage outputted by the DC power supply circuit 510 is adjustable. The adjustable voltage is outputted to the power amplifier 520 , so that the output power of the power amplifier 520 can be adjusted.

[0129] The signal modulation circuit 530 receives the high-frequency clock pulse generated by the high-frequency clock circuit 540 . The signal modulation circuit 530 can adjust the high-frequency clock pulse and then transmit the adjusted high-frequency clock pulse to the power amplifier 520 , thereby achieving a small range adjustment of the output power of the power amplifier 520 .

[0130] The power amplifier 520 amplifies the input signal according to the adjustment of the pulse width of the high-frequency clock pulse by the signal modulation circuit 530 and the DC voltage provided by the DC power supply circuit 510, and then transmits it to the resonant transmitting coil 570, and finally presents an amplitude shift keying (ASK) modulated voltage waveform on the resonant transmitting coil 570, and the modulation depth can be determined by the pulse width of the high-frequency clock pulse and the DC voltage.

[0131] When the ASK modulated voltage waveform is applied to the resonant transmitting coil 570, the change in the voltage waveform causes the current in the resonant transmitting coil 570 to change accordingly, and the changing current will generate a changing magnetic field in space. This changing magnetic field can propagate to the surrounding space in the form of electromagnetic waves, thereby realizing wireless energy transmission or signal transmission.

[0132] The resonant transmitting coil 570 can receive the communication signals sent by the implantable medical device and transmit the communication signals to the signal demodulation circuit 550. The signal demodulation circuit 550 demodulates the communication signals, extracts the target information, and transmits the target information to the main control unit 560 for further analysis and processing.

[0133] In an embodiment of the present application, the implantable medical device can perform wireless energy transmission and wireless communication with an external transmitting end based on the coupling of the coil pair.

[0134] like Figure 6 As shown, Figure 6 It is a flow chart of a wireless energy transmission method provided in an embodiment of the present application.

[0135] The wireless energy transmission method can be applied to an implantable medical device, which includes a receiving coil, a rectifier circuit, an electrical stimulation module, a load balancing circuit and a controllable load.

[0136] The wireless energy transmission method may include the following steps:

[0137] S601: The receiving coil receives energy sent by the sending coil of the sending end and outputs an AC voltage;

[0138] S602: The rectifier circuit converts the AC voltage into a DC voltage;

[0139] S603: The electrical stimulation module has a first working state and a second working state, the electrical stimulation module outputs stimulation pulses when in the first working state, and does not output stimulation pulses when in the second working state;

[0140] S604: When the electrical stimulation module is in the second working state, the load balancing circuit controls the controllable load to be connected to the DC output end of the rectifier circuit, and controls the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, and the preset range is determined according to the power consumption of the electrical stimulation module in the first working state.

[0141] About load balancing circuit:

[0142] In some embodiments, the load balancing circuit includes a control unit and a switch circuit;

[0143] The load balancing circuit controls the controllable load to be connected to the DC output end of the rectifier circuit when the electrical stimulation module is in the second working state, including:

[0144] The control unit generates a control signal according to the working state of the electrical stimulation module;

[0145] The control end of the switch circuit receives the control signal, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state, so as to connect the controllable load to the DC output end of the rectifier circuit.

[0146] In some embodiments, the electrical stimulation module comprises a storage unit, the storage unit is used to store the working parameters of the electrical stimulation module, the working parameters include the frequency, width and / or amplitude of the stimulation pulse output by the electrical stimulation module;

[0147] The control unit generates a control signal according to the working state of the electrical stimulation module, including:

[0148] The control unit obtains the operating parameters from the storage unit;

[0149] Determining the working state of the electrical stimulation module according to the working parameters;

[0150] A control signal is generated according to the working state of the electrical stimulation module.

[0151] In some embodiments, the control signal includes a pulse width modulation (PWM) wave, and the switch circuit includes an NMOS tube; the control end of the switch circuit receives the control signal, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state, including:

[0152] The gate of the NMOS tube receives the PWM wave, and the NMOS tube is turned on when the PWM wave is at a high level.

[0153] About controllable load:

[0154] In some embodiments, the controllable load includes at least one of the following: a resistor array, a tank circuit.

[0155] The implementation process of each step in the above-mentioned wireless energy transmission method is specifically described in the implementation process of the functions and effects of the corresponding parts in the above-mentioned implantable medical device, which will not be repeated here.

[0156] like Figure 7 As shown, Figure 7This is a schematic diagram of the structure of an implantable medical device provided by another embodiment of the present application. The implantable medical device may include: a receiving coil, a resonant circuit, an impedance matching circuit, a rectifier circuit, a filter module, a power supply network, an electrical stimulation module, a control unit, a switch circuit, a controllable load, a downlink demodulation module, and an uplink modulation module.

[0157] The implantable medical device can perform wireless energy transmission and wireless communication with an external transmitting end based on the coupling of a coil pair, wherein the coil pair includes a receiving coil of the implantable medical device and a transmitting coil of the transmitting end.

[0158] The receiving coil receives the energy sent by the transmitting coil at the transmitting end and outputs an AC voltage, which is transmitted to the resonant circuit. The resonant circuit can adjust and optimize the frequency of the AC voltage to ensure that it matches the resonant frequency of the receiving coil. The AC voltage processed by the resonant circuit will be further transmitted to the impedance matching circuit. The impedance matching circuit can adjust and optimize the impedance characteristics of the circuit to ensure that the input impedance of the implantable medical device matches the characteristic impedance of the transmission line.

[0159] The rectifier circuit converts the AC voltage after the above processing into a DC voltage. The filter circuit can smooth the pulsating DC voltage output by the rectifier circuit and reduce the ripple in the voltage (that is, the AC component in the voltage). The power supply network will store, monitor and distribute the electrical energy rectified by the rectifier circuit.

[0160] The electrical stimulation module includes a storage unit, which is used to store working parameters of the electrical stimulation module, including the frequency, width and amplitude of the stimulation pulse output by the electrical stimulation module. The electrical stimulation module can work based on the DC voltage output by the rectifier circuit, and the electrical stimulation module is in a first working state and a second working state according to the working parameters, wherein the first working state includes the electrical stimulation module outputting the stimulation pulse, and the second working state includes the electrical stimulation module not outputting the stimulation pulse.

[0161] The control unit obtains working parameters from the storage unit of the electrical stimulation module, determines the working state of the electrical stimulation module according to the working parameters, generates a control signal according to the working state of the electrical stimulation module, and transmits the control signal to the switching circuit. The control unit can also determine the power consumption of the electrical stimulation module in a first working state according to the working parameters, and determine a preset range according to the power consumption of the electrical stimulation module in the first working state.

[0162] The control end of the switch circuit receives a control signal, which is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state (that is, the electrical stimulation module does not output stimulation pulses) so as to connect the controllable load to the DC output end of the rectifier circuit, and to control the switch circuit to be disconnected when the electrical stimulation module is in the first working state (that is, the electrical stimulation module outputs stimulation pulses) so as not to connect the controllable load to the DC output end of the rectifier circuit.

[0163] After the controllable load is connected to the DC output end of the rectifier circuit, the control unit controls the controllable load, controls and adjusts the power consumption of the controllable load, so that the sum of the power consumption of the controllable load and the electrical stimulation module in the second working state (i.e., the electrical stimulation module does not output stimulation pulses) is within a preset range.

[0164] By controlling the controllable load to dynamically access the DC output end of the rectifier circuit, when the electrical stimulation module switches between the first working state and the second working state, the load change of the implantable medical device is stable, thereby reducing the fluctuation of the reflected impedance of the transmitting end, ensuring that the transmitting end power amplifier outputs a stable voltage signal, and thus avoiding erroneous demodulation data output of the implantable medical device based on coil-pair coupling communication, thereby improving the effectiveness and accuracy of communication.

[0165] It should be noted that, in this article, relational terms such as target and target are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0166] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An implantable medical device, characterized in that: include: The receiving coil is used to receive the energy sent by the sending coil at the sending end and output an AC voltage; A rectifier circuit, used for converting the AC voltage into a DC voltage; an electrical stimulation module, having a first working state and a second working state, wherein the electrical stimulation module outputs stimulation pulses when in the first working state and does not output stimulation pulses when in the second working state; a load balancing circuit, configured to control a controllable load to be connected to a DC output terminal of the rectifier circuit when the electrical stimulation module is in the second working state, and to control the controllable load so that the sum of the power consumption of the controllable load and the electrical stimulation module is within a preset range, wherein the preset range is determined according to the power consumption of the electrical stimulation module in the first working state; The load balancing circuit comprises: A control unit, configured to generate a control signal according to the working state of the electrical stimulation module; A switch circuit, wherein the control end of the switch circuit receives the control signal, and the control signal is used to control the switch circuit to be turned on when the electrical stimulation module is in the second working state, so as to connect the controllable load to the DC output end of the rectifier circuit.

2. The implantable medical device according to claim 1, characterized in that: The electrical stimulation module comprises a storage unit, and the storage unit is used to store the working parameters of the electrical stimulation module, and the working parameters include the frequency, width and / or amplitude of the stimulation pulse output by the electrical stimulation module; The control unit is specifically used for: Acquire the operating parameters from the storage unit; Determining the working state of the electrical stimulation module according to the working parameters; A control signal is generated according to the working state of the electrical stimulation module.

3. The implantable medical device according to claim 1, characterized in that: The control signal includes a pulse width modulation (PWM) wave, and the switch circuit includes an NMOS tube; The NMOS tube is specifically used for: The gate of the NMOS tube receives the PWM wave, and the NMOS tube is turned on when the PWM wave is at a high level.

4. The implantable medical device according to claim 1, characterized in that: The controllable load includes at least one of the following: a resistor array and an energy storage circuit.

5. The implantable medical device according to claim 4, characterized in that: The energy storage circuit comprises an adjustable constant current source and an energy storage unit, wherein the adjustable constant current source is used to charge the energy storage unit; The load balancing circuit is specifically used for: When the electrical stimulation module is in the second working state, controlling the energy storage circuit to be connected to the DC output terminal of the rectifier circuit; The output current of the adjustable constant current source is controlled so that the sum of the power consumption of the energy storage circuit and the electrical stimulation module is within the preset range.

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