Closed-loop transcutaneous wireless energy transfer system that meets human thermal safety

Abstract

The application discloses a closed-loop transcutaneous wireless energy transmission system in line with human thermal safety, which comprises a transmitting end for transmitting wireless energy, a receiving end for receiving wireless energy and an energy storage module connected with the receiving end, wherein the energy storage module outputs current to a master control circuit in an artificial anal sphincter prosthesis, and the transmitting end collects in-vivo voltage information from the receiving end and performs closed-loop control. The application adopts a high-order compensation network and closed-loop control to realize controllable output voltage, and can maintain the output voltage unchanged during the charging process regardless of whether the coil is offset or tilted, so that the highest temperature of the equipment is ensured to be not higher than 42.5 DEG C.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless powered medical devices, and particularly relates to a closed-loop transcutaneous wireless energy transmission system conforming to human thermal safety. BACKGROUND

[0002] A safe and stable transcutaneous wireless energy transmission system is the key to the clinical application of artificial anal sphincter. The existing transcutaneous wireless energy transmission system adopts a series-series compensation network, and the output voltage changes with the change of the receiving end impedance, which leads to the instability of the receiving end voltage during the charging process, and it is difficult to control. In addition, the receiving end is easy to deviate or tilt after being implanted in the body, which leads to the change of mutual inductance between the transmitting and receiving coils. If the transmitting voltage is not adjusted accordingly, it will lead to insufficient receiving voltage. The existing receiving end integrates the battery, coil and receiving end circuit, and the human tissue thermal safety is not fully considered in the design. High temperature will occur in a short time during the charging process, which is easy to scald the implanted tissue. SUMMARY

[0003] The present application is aimed at the problem that the receiving end voltage of the existing wireless in-vivo charging technology cannot be controlled constantly, which leads to easy overheating of the device, and the deficiency that the transmitting power cannot be accurately controlled in a closed loop according to the change of mutual inductance. A closed-loop transcutaneous wireless energy transmission system conforming to human thermal safety is proposed, which adopts a high-order compensation network and closed-loop control to realize controllable output voltage. Whether the coil deviates or tilts during the charging process, the output voltage can be maintained unchanged, which ensures the receiving power and the maximum temperature of the device does not exceed 42.5 DEG C.

[0004] The present application is realized by the following technical solutions:

[0005] The present application relates to a closed-loop transcutaneous wireless energy transmission system conforming to human thermal safety, comprising a transmitting end for transmitting wireless energy, a receiving end for receiving wireless energy, and an energy storage module connected to the receiving end, wherein: the energy storage module outputs current to the main control circuit in the artificial anal sphincter prosthesis, and the transmitting end collects the in-vivo voltage information from the receiving end and performs closed-loop control.

[0006] The transmitting end comprises a control module and a power module, a wireless communication module, a sampling module and an inverter module connected to the control module respectively, wherein: the control module calculates the voltage value of the transmitting end voltage to be adjusted according to the in-vivo voltage information, generates the PWM signal required by the inverter module, and simultaneously performs closed-loop control on the transmitting power; the wireless communication module receives the in-vivo voltage information from the in-vivo master control circuit in the artificial anal sphincter prosthesis and inputs the in-vivo voltage information to the control module; the sampling module collects the input DC voltage, input current and battery voltage of the inverter module in real time; the inverter module converts the DC voltage into a square wave according to the PWM signal and inputs the square wave into the compensation topology module with a high-order compensation network, the compensation topology module and the transmitting coil form a high-order resonant circuit, the transmitting coil is opposite to the receiving end and outputs wireless energy.

[0007] The receiving end comprises a circular receiving circuit, a ring-shaped coil, a spliced magnetic isolation sheet and a combined heat sink, wherein: the circular receiving circuit is arranged in the central groove of the spliced magnetic isolation sheet, and the combined heat sink is attached to the back of the circular receiving circuit and the spliced magnetic isolation sheet.

[0008] The closed-loop control refers to that: after receiving the in-vivo voltage information, the control module calculates the difference value ΔU2 between the in-vivo voltage information and the set voltage, calculates the value ΔU1 of the transmitting voltage to be adjusted according to the relationship between the receiving voltage and the transmitting voltage under the high-order compensation topology, and then adjusts the transmitting voltage by the PID algorithm according to the relationship between the control voltage output by the control module and the output voltage of the BUCK circuit in the power module, so as to realize the closed-loop control.

[0009] Technical effects

[0010] Compared with the prior art, the combination of the high-order compensation network and the closed-loop control method realizes the constant receiving voltage when the mutual inductance of the coil is constant or changes, and the low temperature rise in the charging process is realized by improving the receiving end. When the coil is offset or tilted, the transmitting power and the coil position do not need to be adjusted in real time, and at the same time, the problem of overheating and burning of the tissue of the receiving end of the existing transcutaneous energy transmission system can be solved, and the receiving end will not exceed the upper limit of the human body thermal safety temperature during the charging process. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a schematic diagram of the system of the present application;

[0012] Figure 2 It is a closed-loop control principle diagram of the embodiment;

[0013] Figure 3 It is a voltage regulation control circuit schematic diagram of the embodiment;

[0014] Fig. 4 is a receiving end schematic diagram of the embodiment;

[0015] Figure 5 It is a distribution schematic diagram of the energy storage module of the embodiment;

[0016] Figure 6A and Figure 6B Transmission performance effect diagram for the embodiment;

[0017] Figure 7 Temperature rise comparison effect diagram for the embodiment and prior art;

[0018] In the figure: transmitting end 1, receiving end 2, artificial anal sphincter prosthesis 3, energy storage module 4, in-vivo main control circuit 5, control module 102, and power supply module 101, wireless communication module 103, sampling module 107, display module 108, inverter module 104, compensation topology module 105, transmitting coil 106, circular receiving circuit 203, annular coil 201, spliced magnetic isolation sheet 202, combined heat sink 204, 205, lithium battery combination 301, charging management module 302, series compensation capacitor 203-1, four Schottky diodes 203-2, voltage stabilizing chip 203-3, and voltage detection circuit 203-4 connected thereto. DETAILED DESCRIPTION

[0019] As Figure 1 shown, the embodiment relates to a closed-loop transcutaneous wireless energy transmission system in line with human thermal safety, comprising: transmitting end 1 for transmitting wireless energy, receiving end 2 for receiving wireless energy, and energy storage module 4 connected to receiving end 2, wherein: energy storage module 4 outputs current to in-vivo main control circuit 5 in artificial anal sphincter prosthesis 3, and transmitting end 1 collects in-vivo voltage information from receiving end 2 and performs closed-loop control.

[0020] The transmitting end 1 comprises: control module 102 and power supply module 101, wireless communication module 103, sampling module 107, and inverter module 104 connected thereto, wherein: control module 102 calculates the voltage value that the transmitting end voltage should be adjusted according to the in-vivo voltage information, generates the PWM signal required by the inverter module while performing closed-loop control on the transmitting power; wireless communication module 103 receives the in-vivo voltage information sent by in-vivo main control circuit 5 in artificial anal sphincter prosthesis 3 and inputs it to control module 102; sampling module 107 collects the input DC voltage, input current, and battery voltage of inverter module 104 in real time; inverter module 104 converts the DC voltage into a square wave according to the PWM signal and inputs it into compensation topology module 105 with a high-order compensation network, and compensation topology module 105 and transmitting coil 106 form a high-order resonant circuit, and transmitting coil 106 is directly opposite receiving end 2 and outputs wireless energy.

[0021] The power supply module 101 comprises: lithium battery, adjustable BUCK circuit, and voltage stabilizing module, wherein: the adjustable BUCK circuit outputs the adjusted voltage to inverter circuit 104 as input DC voltage.

[0022] The transmitter 1 is further provided with a display module 108 connected to the control module 102. The display module uses an LCD screen to display the transmitter voltage and current information and the internal voltage information during the charging process.

[0023] The transmitting coil 106 is a planar spiral coil with a manganese-zinc ferrite magnetic shielding sheet attached to its back to improve the quality factor.

[0024] like Figure 2 As shown, the closed-loop control refers to the following: after receiving the internal voltage information, the control module 102 calculates the difference △U2 between it and the set voltage, calculates the value △U1 that the transmission voltage needs to be adjusted according to the relationship between the received voltage and the transmitted voltage under the high-order compensation topology, and then inputs △U1 into the PID algorithm to adjust the transmission voltage according to the relationship between the output voltage of the control module and the BUCK output voltage in the power supply module, thereby realizing closed-loop control.

[0025] The relationship between the received voltage and the transmitted voltage specifically refers to: Among them: U o To receive voltage, U i Where is the transmitting voltage, M is the mutual inductance of the coils, and L1 is the series compensation inductance.

[0026] like Figure 3 As shown, the relationship between the output voltage of the control module and the output voltage of the BUCK circuit in the power supply module refers to: Where: V B V is the output voltage of the BUCK circuit. C R1 and R2 are the voltage regulator resistors for the output voltage of the control module, and R3 is the resistor that applies the control module voltage to the reference voltage point A. F V is the reference voltage for the internal chip of the BUCK circuit. d The voltage drop of diode D1 in the output branch of the control module.

[0027] The control module outputs a control voltage V via a DAC. C By changing the voltage at the reference voltage point of the BUCK circuit chip, the BUCK output voltage V is thus changed. B It changes with the reference voltage at point A.

[0028] The high-order compensation network is an LCC compensation network composed of a series compensation inductor, a parallel compensation capacitor, and a coil series compensation capacitor.

[0029] In this embodiment, the series compensation inductor is a wire-wound chip inductor, the parallel compensation capacitor is a chip ceramic capacitor, and the coil series compensation capacitor is a high-voltage CBB capacitor that can withstand high-frequency current.

[0030] likeFigure 4A As shown in the figure, the receiving end 2 comprises a combination of heat sinks 204, 205, and a spliced magnetic isolation sheet 202, a circular receiving circuit 203 and a ring-shaped coil 201 connected thereto, wherein the circular receiving circuit 203 is arranged in the middle of the ring-shaped coil 201.

[0031] As shown in the figure, the circular receiving circuit 203 comprises a series compensation capacitor 203-1, four Schottky diodes 203-2, a voltage stabilizing chip 203-3 and a voltage detection circuit 203-4, wherein the voltage stabilizing chip 203-3 is arranged at the center of the circuit board, the four Schottky diodes 203-2 are arranged diagonally, and the voltage detection circuit 203-4 is arranged at the edge. Figure 4B

[0032] The ring-shaped coil 201 adopts a single-layer planar spiral coil, and the inner diameter is 1mm larger than the outer diameter of the circular receiving circuit.

[0033] The spliced magnetic isolation sheet 202 adopts a ferrite magnetic isolation sheet, which comprises a center circular magnetic isolation sheet above the circuit board and a ring-shaped magnetic isolation sheet below the ring-shaped coil, wherein the outer edge of the center circular magnetic isolation sheet and the inner edge of the ring-shaped magnetic isolation sheet are overlapped and fixed with glue.

[0034] The outer diameter of the center circular magnetic isolation sheet is 1mm larger than the outer diameter of the circular circuit board, which is used to reduce the eddy current effect of the electromagnetic field on the circuit board and increase the mutual inductance of the coil. The inner diameter of the ring-shaped magnetic isolation sheet is slightly larger than the outer diameter of the circuit board, and the outer diameter is consistent with the outer diameter of the coil.

[0035] The combination of heat sinks comprises a heat-conducting silica gel sheet 204 pasted on the receiving circuit board and a graphene heat-conducting sheet 205 pasted on the overall surface of the receiving end.

[0036] The outer diameter of the heat-conducting silica gel sheet is consistent with the outer diameter of the receiving circuit board, and the outer diameter of the graphene heat-conducting sheet is consistent with the outer diameter of the ring-shaped magnetic isolation sheet.

[0037] As shown in the figure, when the energy storage module 4 is arranged in the artificial anal sphincter prosthesis 3, a plurality of lithium battery combinations 301 and a plurality of corresponding charging management modules 302 are adopted. Figure 5 The in-vivo main control circuit 5 comprises a microcontroller and an in-vivo wireless communication module, wherein the microcontroller outputs the collected in-vivo voltage information to the transmitting end 1 through the in-vivo wireless communication module.

[0038]

[0039] ​​In the environment where the room temperature is constant at 23℃, the receiving end is placed under the fresh pork skin at 10mm, the transmitting coil is set on the surface of the pork skin, and the experiment of transcutaneous wireless energy transmission is carried out for 1 hour under the initial transmitting voltage of 7V and the initial transmitting current of 0.21A. The experimental results show that the receiving voltage is basically stable and unchanged within 1 hour, the in-vivo battery voltage is charged from 3.35V to 3.79V within 1 hour, and the average transmission efficiency is 92.7%. The temperature of this embodiment rises from 27.6℃ to 33.2℃ under the condition of 1 hour charging, and the temperature rise is 5.6℃. The theoretical maximum temperature of the implanted body is 42.1℃, and the actual temperature will be lower after the blood flow carries away part of the heat, which meets the human body thermal safety.

[0040] As shown in Figure 6A and Figure 6B the effect diagram of the in-vitro charging for 1 hour by using the embodiment is shown.

[0041] As shown in Figure 7 the temperature rise comparison effect diagram of the embodiment and the prior art under the condition of 1 hour charging is shown.

[0042] Compared with the prior art, the average transmission efficiency of the present application is increased from 87.2% of the prior art to 92.7% during the 1 hour charging process, the maximum temperature rise of the receiving end is 5.6℃, which is about 78% lower than the temperature rise of 25.4℃ of the prior art, and can meet the human body thermal safety.

[0043] The above specific embodiments can be adjusted in different ways by those skilled in the art without departing from the principles and purposes of the present application, the protection scope of the present application is subject to the claims and is not limited by the above specific embodiments, and each implementation scheme within the scope is subject to the constraints of the present application.

Claims

1. A closed loop transcutaneous wireless energy transfer system in compliance with human thermal safety, characterized in that, The application relates to a transmitting end for transmitting wireless energy, a receiving end for receiving wireless energy and an energy storage module connected with the receiving end, wherein the energy storage module outputs current to a master control circuit in an artificial anal sphincter prosthesis, the transmitting end collects in-vivo voltage information from the receiving end and performs closed-loop control. The transmitting end comprises a control module and a power supply module with a BUCK circuit, a wireless communication module, a sampling module and an inverter module connected with the control module, wherein the control module calculates a voltage value to which the voltage of the transmitting end should be adjusted according to the in-vivo voltage information, generates a PWM signal required by the inverter module and performs closed-loop control on the transmitting power; the wireless communication module receives in-vivo voltage information from an in-vivo master control circuit in the artificial anal sphincter prosthesis and inputs the in-vivo voltage information into the control module; the sampling module collects input direct-current voltage, input current and battery voltage of the inverter module in real time; the inverter module converts the direct-current voltage into a square wave according to the PWM signal and inputs the square wave into a compensation topology module with a high-order compensation network; the compensation topology module and a transmitting coil form a high-order resonant loop; the transmitting coil faces the receiving end and outputs wireless energy. The receiving end comprises a circular receiving circuit, a ring-shaped coil, a spliced magnetic isolation sheet and a combined heat dissipation sheet, wherein the circular receiving circuit is arranged in a central groove of the spliced magnetic isolation sheet, and the combined heat dissipation sheet is attached to the back of the circular receiving circuit and the spliced magnetic isolation sheet. The power supply module comprises a lithium battery, an adjustable BUCK circuit and a voltage stabilizing module, wherein the adjustable BUCK circuit outputs the adjusted voltage to the inverter circuit as input direct-current voltage. The transmitting coil adopts a planar spiral coil, and a manganese-zinc ferrite magnetic isolation sheet is attached to the back of the transmitting coil to improve the quality factor.

2. The closed-loop, transcutaneous, wireless energy transfer system of claim 1, wherein, The circular receiving circuit comprises series compensation capacitors, four Schottky diodes, a voltage stabilizing chip and a voltage detection circuit, wherein the voltage stabilizing chip is arranged at the center of a circuit board, the four Schottky diodes are arranged at the corners in dispersion, and the voltage detection circuit is arranged at the edge.

3. The closed loop, transcutaneous, wireless energy transfer system for human thermal safety according to claim 1, wherein, The ring-shaped coil adopts a single-layer planar spiral coil.

4. The closed loop, transcutaneous, wireless energy transfer system for human thermal safety according to claim 1, wherein, The spliced magnetic isolation sheet adopts a ferrite magnetic isolation sheet and comprises a central circular magnetic isolation sheet above a circuit board and a ring-shaped magnetic isolation sheet below the ring-shaped coil, wherein the outer edge of the central circular magnetic isolation sheet and the inner edge of the ring-shaped magnetic isolation sheet are overlapped and fixed by glue. The combined heat dissipation sheet comprises a heat-conducting silica gel sheet attached to the receiving circuit board and a graphene heat-conducting sheet attached to the surface of the receiving end.

5. The closed loop, transcutaneous, wireless energy transfer system for human thermal safety according to claim 1, wherein, The in-vivo master control circuit comprises a microcontroller and an in-vivo wireless communication module, wherein the microcontroller outputs the collected in-vivo voltage information to the transmitting end through the in-vivo wireless communication module.

6. The closed loop, transcutaneous, wireless energy transfer system for human thermal safety according to claim 1, wherein, The closed-loop control refers to that after the control module receives the in-vivo voltage information, the control module calculates the difference value Delta U2 between the in-vivo voltage information and a set voltage, calculates the value Delta U1 to which the transmitting voltage should be adjusted according to the relationship between the receiving voltage and the transmitting voltage under the high-order compensation topology, adjusts the transmitting voltage according to the relationship between the control voltage output by the control module and the output voltage of the BUCK circuit in the power supply module and the PID algorithm, and realizes the closed-loop control.

7. A closed loop transcutaneous wireless energy transfer system consistent with human thermal safety according to any one of the preceding claims, wherein, The reference voltage point is the reference voltage output end of the internal chip of the BUCK circuit.

8. The closed loop, transcutaneous, wireless energy transfer system of claim 7, wherein, The relationship between the receiving voltage and the transmitting voltage is specifically as follows: Wherein: U o is the receiving voltage, U i is the transmitting voltage, M is the mutual inductance value of the coil, and L1 is the series compensation inductance value. The relationship between the control module output voltage and the BUCK circuit output voltage in the power module is: Wherein: is the BUCK circuit output voltage, is the control voltage output by the control module, and is the voltage regulating resistor of the two BUCK circuits, is the resistor through which the control module voltage acts on the reference voltage point, is the internal chip reference voltage of the BUCK circuit, is the voltage drop of the diode D1 in the control module output branch, and the control module outputs the control voltage through the DAC Changes the voltage at the BUCK circuit chip reference voltage point, and further changes the BUCK output voltage Changes with the change of the A point reference voltage; ​ a first voltage regulating resistor a second voltage regulating resistor disposed between the reference voltage point and the output voltage of the BUCK circuit a resistor disposed between the reference voltage point and the ground potential, through which the voltage of the control module acts on the reference voltage point and a diode D1 of the output branch of the control module is disposed between the reference voltage point and the output of the control module in turn.

9. The closed loop, transcutaneous, wireless, energy transfer system in compliance with human thermal safety according to claim 1, characterized by, The high-order compensation network is an LCC compensation network composed of series compensation inductance, parallel compensation capacitance and coil series compensation capacitance.

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