WO2021185371A1

WO2021185371A1 - Implantable diaphragm pacemaker

Info

Publication number: WO2021185371A1
Application number: PCT/CN2021/081937
Authority: WO
Inventors: 石岩; 顾小玉; 蔡茂林; 许未晴; 王一轩; 任帅; 王娜
Original assignee: 北京航空航天大学
Priority date: 2020-03-20
Filing date: 2021-03-20
Publication date: 2021-09-23
Also published as: CN111298292A; CN111298292B

Abstract

Provided is an implantable diaphragm pacemaker, comprising an extracorporeal controller, a wireless power supply module, a receiver and a stimulating electrode, wherein the receiver and the stimulating electrode are implanted into a body, the stimulating electrode is located on a diaphragm and uses a dual electrode to bidirectionally stimulate phrenic nerves on the diaphragm, the receiver is implanted into the epidermis near a collarbone, and the stimulating electrode is electrically connected to the receiver; the interior of the receiver is provided with a constant-current stimulating circuit for controlling a constant-current signal input into the stimulating electrode; and the extracorporeal controller and the receiver are subjected to wireless two-way communication by means of a wireless communication circuit, the extracorporeal controller wirelessly supplies power to the receiver by means of the wireless power supply module, the receiver receives parameters set by the extracorporeal controller, and the extracorporeal controller receives a feedback signal from the receiver, thereby controlling the operation of the wireless power supply module and realizing control over the receiver.

Description

Implantable diaphragm pacemaker

Technical field

The invention relates to the field of medical technology, and more specifically to an implantable diaphragm pacemaker.

Background technique

The diaphragm is located between the chest cavity and the abdominal cavity. It is a dome-shaped platys gracilis muscle that swells upwards. It is the main respiratory muscle and bears 60% to 70% of the inspiratory function. The diaphragm is a skeletal muscle and is innervated by the phrenic nerve. It expands and contracts to complete one exhalation and inhalation. When the patient has difficulty breathing or even cannot breathe spontaneously due to diseases such as high spinal cord injury and chronic obstructive pulmonary disease, the diaphragm pacemaker can be used to restore the patient's spontaneous breathing function.

At present, diaphragm pacemakers can be divided into two types: implantable and external according to the placement of electrodes. External diaphragm pacemakers are widely studied and used in my country. Sun Yat-sen University of Medical Sciences in China successfully invented the external diaphragm pacemaker in 1987. However, the external diaphragm pacemaker is difficult to accurately position the electrode and the stimulation intensity is roughly the same. The treatment effect is not obvious. It can only be used as an auxiliary treatment method for the reconstruction of the patient's respiratory function, and cannot fully restore the patient's spontaneous respiratory function. The implantable diaphragm pacemaker is a kind of diaphragm pacemaker that needs to be implanted in the body. The basic principle is to stimulate the phrenic nerve through electrical pulses to trigger diaphragm contraction, thereby simulating the breathing movement of the human body’s physiological pattern, and implanting diaphragmatic pacing The device is usually used for ventilatory dysfunction, chronic obstructive pulmonary disease, quadriplegia and ventilatory insufficiency caused by high cervical spinal cord injury.

Compared with the external type, the implanted diaphragm pacemaker has the advantages of low current stimulation and low pacing energy to achieve the effect of stable breathing, effectively helping the patient to achieve spontaneous breathing, removing the patient from the ventilator, and improving the quality of life of the patient. In the 1960s, Glenn successfully developed an implantable diaphragm pacemaker. At present, it is mainly produced by three companies: Avery, Atrotech, and Medimplant. However, due to its high price, long supply cycle, The shortcomings such as inconvenient product maintenance are not accepted by patients; although foreign technology has been quite mature, the domestic development of implantable diaphragm pacemakers is only at the experimental stage. The existing traditional implantable diaphragm pacemakers in China do not consider outputting a controllable constant current to the diaphragm pacing electrodes, which is likely to cause damage to the phrenic nerve and diaphragm of the patient.

Therefore, how to achieve a controllable and constant current output of the implantable diaphragm pacemaker and avoid damage to the phrenic nerve and diaphragm is an urgent problem for those skilled in the art to solve.

Summary of the invention

In view of this, the present invention provides an implantable diaphragm pacemaker, the receiver of which can output a controllable constant current to the diaphragm pacing electrode and then to the phrenic nerve, effectively avoiding diaphragm and phrenic nerve damage and fatigue.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

An implantable diaphragm pacemaker, comprising: an external controller, a wireless power supply module, two receivers and two stimulation electrodes; the external controller is electrically connected to the wireless power supply module; the wireless power supply module is connected to the The receiver is wirelessly connected to supply power to the receiver; each of the receivers is electrically connected to one of the stimulation electrodes, and the two stimulation electrodes output bidirectional pulse currents; the receiver and the external controller Perform wireless communication; the external controller transmits a wireless signal to the receiver through a wireless communication circuit, and the receiver controls the station through the second microprocessor in the receiver and the bidirectional constant current stimulation circuit according to the wireless signal The current amplitude and pulse interval output by the receiver, the receiver induces the change in the magnetic field of the wireless power supply module to generate an induced current, and outputs a controllable constant current to act on the stimulation electrode to stimulate the phrenic nerve, thereby stimulating the phrenic nerve. The diaphragm is contracted, and the controllable constant current repeatedly stimulates the phrenic nerve in a cycle, which approximates a breathing movement in a physiological pattern.

Preferably, the receiver and the stimulation electrode are implanted in the body, the stimulation electrode is located on the phrenic nerve, and the receiver is implanted in the receiver near the second rib of the thoracic cavity. The receiver is electrically connected; the wireless power supply transmitting circuit in the wireless power supply module is attached to the upper side of the skin where the receiver is located.

Preferably, the external controller includes a power management system, a wireless communication circuit, a wireless power supply control circuit, a voltage and current detection circuit, a human-computer interaction circuit, and a microprocessor one; the power management system includes a battery protection circuit, a battery Charging circuit, load switch circuit, step-down circuit one, main power supply switch, wireless power supply switch one and wireless power supply switch two; the human-computer interaction circuit controls power supply through the load switch circuit, and is connected to the microprocessor one; The wireless communication circuit controls power supply through the load switch circuit, and is connected to the microprocessor one for wireless communication with the receiver; the wireless power supply control circuit controls power supply through the load switch circuit, and communicates with The wireless power supply module is connected; the microprocessor is connected to the voltage and current detection circuit through the load switch circuit; the step-down circuit is connected to the battery protection circuit and the load switch circuit; The battery protection circuit and the charging circuit are connected to a power source; the wireless power supply module is connected to the wireless power supply power control circuit through the wireless power supply switch; the battery connected to the battery protection circuit is electrically connected to the power supply main switch, so The main power supply switch is electrically connected to the step-down circuit; the battery protection circuit is electrically connected to the battery charging circuit, the step-down circuit is electrically connected to the battery protection circuit, and the step-down circuit is electrically connected to The load switch circuit, the human-computer interaction circuit and the microprocessor are electrically connected;

The wireless power supply control circuit includes a power supply control circuit one and a wireless power supply control circuit two, and the load switch circuit is electrically connected to the wireless power supply control circuit one and the wireless power supply control circuit two; The first power supply control circuit is connected to the wireless power supply module through the first wireless power supply switch, and the second wireless power supply control circuit is connected to the wireless power supply module through the second wireless power supply switch; the microprocessor first determines the wireless power supply. Whether the power supply switch is closed, so as to realize the power supply of the load switch circuit to the wireless power supply control circuit.

Preferably, the external controller is used to adjust the current amplitude, pulse interval, and respiration frequency of the receiver; the breathing cycle is adjustable in the range of 5-30 times/min, and the current amplitude is adjustable in the range of 0-10mA, The pulse interval is adjustable in the range of 10-200ms; the power management system is mainly used to control battery charging and discharging, and to control the power supply and power off of each module; the wireless communication circuit mainly switches the microprocessor one and the Mutual communication between receivers; the wireless power supply control circuit limits the wireless transmission power of the wireless power supply module within a certain range to limit the voltage received by the receiver, and the wireless power supply of the wireless power supply module The first transmitting circuit and the second wireless power supply transmitting circuit are used for wireless power supply; the voltage and current detection circuit is used to detect battery voltage and total current, and the current in the wireless power supply control circuit. If the circuit is found to be abnormal, it includes wireless Whether the power supply transmitter circuit is in good contact with the external controller, the health of the battery, etc., will prompt the corresponding abnormal content, and if necessary, start the protection program to cut off the power; the microprocessor 1 controls and coordinates the work of the other circuits.

Preferably, the receiver includes a rectifier circuit, a step-down circuit two, a bidirectional constant current stimulation circuit, and a microprocessor two; the rectifier circuit is connected with a receiving coil, and is connected to the wireless power supply module by radio through the receiving coil The rectifier circuit is electrically connected to the second step-down circuit; the second microprocessor is electrically connected to the second step-down circuit and the two-way constant current stimulation circuit; the receiving coil receives alternating current and transmits it to the rectifier The circuit is rectified and transmitted to the second step-down circuit for step-down processing, and finally powers the second microprocessor and the bidirectional constant current stimulation circuit of the receiver; the second microprocessor is the bidirectional constant current stimulation circuit. The current stimulation circuit is powered; the wireless communication function module of the second microprocessor performs wireless communication with the wireless communication circuit of the external controller; the bidirectional constant current stimulation circuit is connected to the stimulation electrode through an electrode connector. The receiver receives and executes the parameters set by the external controller, wherein the rectifier circuit is used to rectify and filter the alternating current generated by the wireless power supply module into direct current, which is the second step of the step-down circuit And the two-way constant current stimulation circuit to supply power; the second step-down circuit is used to reduce the higher voltage after rectification to the voltage required by the second microprocessor and the two-way constant current stimulation circuit; the micro-processing The second device is used to execute each control mode; the wireless communication function module of the second microprocessor performs wireless communication with the wireless communication circuit of the external controller, so as to realize the wireless communication with the first microprocessor The constant current stimulation circuit is connected to the stimulation electrode through an electrode connector, and is used to control the magnitude and direction of the stimulation current. The wireless communication function module is a self-contained function module of the second microprocessor.

Preferably, the wireless power supply module includes a wireless power supply transmitting circuit one and a wireless power supply transmitting circuit two, which are respectively wirelessly connected to the receiving coil of one of the receivers to supply energy; the wireless power supply transmitting circuit one and the The configuration of the second wireless power supply transmitter circuit is the same. The first wireless power supply transmitter circuit includes a transmitter coil and a coil drive circuit; the transmitter coil is connected to the coil drive circuit; the coil drive circuit communicates with the wireless power supply through a wireless power switch. The control circuit is electrically connected; the coil drive circuit and the wireless power supply control circuit are electrically connected through a silicone soft wire to realize the control of the external controller to power the receiver; the wireless power supply transmitter circuit is connected to the wireless power supply switch through the wireless power supply switch. The first wireless power supply power control circuit is connected, and the transmitting coil is wirelessly connected with the receiving coil in one of the receivers to realize the power supply to the receiver; the second wireless power supply transmitting circuit is connected to the wireless power supply switch through the wireless power supply switch. The second wireless power supply control circuit is connected, and the transmitting coil is wirelessly connected to the receiving coil in the other receiver. The wireless power supply between the receiver and the wireless power supply module is based on the principle of wireless electromagnetic induction. The wireless power supply module is jointly controlled by a wireless power supply switch in the external controller and the wireless power supply power control circuit. The wireless power supply power control circuit is electrically connected to the wireless power supply module through a silicone flexible wire. The microprocessor in the device controls the transmit power of the wireless power supply module. When it is detected that the wireless power supply switch is closed, the wireless power supply power control circuit starts to work, thereby controlling the wireless power supply module The strength of the electromagnetic field generated by the transmitting coil limits the induced voltage of the receiver, so that the wireless power supply module can wirelessly supply power to the receiver. The wireless power supply transmitting circuit in the wireless power supply module is attached above the skin where the receiver is located, and the transmitting coil of the wireless power supply transmitting circuit one and the receiving coil of one of the receivers are located The two sides of the skin are arranged opposite to each other, and the transmitting coil of the second wireless power supply transmitting circuit and the receiving coil of the other receiver are arranged opposite to each other on the two sides of the skin.

Preferably, the receiver has a disc shape and is insulated by epoxy resin potting. Since the receiver is implanted near the clavicle and ribs, the wireless power supply module is pasted on the upper skin of the receiver with medical tape. The skin and muscle tissue are thin. The receiver and the wireless power supply module The distance between wireless power supply transmitting circuits is 1~2cm, so it is conducive to wireless charging, reducing power transmission distance and power consumption during power transmission.

Preferably, the bidirectional constant current stimulation circuit is provided with an analog switch chip to generate a bidirectional stimulation current, and the two stimulation electrodes are used to achieve bidirectional stimulation with two electrodes. The use of the bidirectional stimulation can avoid affecting other nerves or muscles other than the phrenic nerve, and also avoid phrenic nerve fatigue. The dual electrodes can output two opposite electrical signals. The external controller can set and adjust the respiratory frequency, intensity, pulse width and other parameters of each signal, and then pass the wireless power supply module The receiver is controlled to generate electrical pulses of a certain width and amplitude according to the set parameters, and finally released through the double electrodes to stimulate the phrenic nerve to achieve control of breathing.

Preferably, the first microprocessor communicates with the second microprocessor through the wireless communication circuit.

Preferably, the human-computer interaction circuit includes a display circuit, an adjustment circuit, and a breathing indication circuit; wherein the display circuit, the adjustment circuit, and the breathing indication circuit are connected to a microprocessor during operation, and the display circuit is connected to the Load switch circuit connection.

It can be known from the above technical solutions that, compared with the prior art, the present disclosure provides an implantable diaphragm pacemaker, including an external controller, a wireless power supply module, a receiver and stimulation electrodes; the receiver and stimulation electrodes are implanted In the body, the stimulating electrode is located on the diaphragm and the phrenic nerve on the diaphragm is bidirectionally stimulated with dual electrodes. The receiver is implanted near the epidermis of the second rib in the thoracic cavity. Input the constant current signal of the stimulation electrode; the external controller and the receiver carry out wireless two-way communication through the wireless communication circuit, the external controller wirelessly powers the receiver through the wireless power supply module, the receiver receives the parameters set by the external controller, and the external controller receives The feedback signal of the receiver thus controls the operation of the wireless power supply module and realizes the control of the receiver. In the present invention, a bidirectional constant current stimulation circuit is added to the receiver to realize precise control of the output stimulation current.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work.

Figure 1 is a schematic diagram of the structure of the implantable diaphragm pacemaker provided by the present invention;

Figure 2 is a schematic diagram of the battery protection circuit provided by the present invention;

Figure 3 is a schematic diagram of the battery charging circuit provided by the present invention;

Figure 4 is a schematic diagram of the step-down circuit provided by the present invention;

Figure 5 is a schematic diagram of the load switch circuit provided by the present invention;

Figure 6 is a schematic diagram of the voltage and current detection circuit provided by the present invention;

Fig. 7 is a schematic diagram of a human-computer interaction circuit provided by the present invention;

Fig. 8 is a schematic diagram of a wireless power supply control circuit provided by the present invention;

Figure 9 is a schematic diagram of a wireless communication circuit provided by the present invention;

Fig. 10 is a schematic diagram of a wireless power supply transmitting circuit provided by the present invention;

Figure 11 is a schematic diagram of a wireless power supply connection provided by the present invention;

Figure 12 is a schematic diagram of the connection of the main power switch provided by the present invention;

Figure 13 is a schematic diagram of a microprocessor provided by the present invention;

Figure 14 is a schematic diagram of the receiver provided by the present invention;

Fig. 15 is a schematic diagram of the rectifier circuit and the step-down circuit provided by the present invention;

Figure 16 is a schematic diagram of the second microprocessor provided by the present invention;

Figure 17 is a schematic diagram of the bidirectional constant current stimulation circuit provided by the present invention;

Figure 18 is a schematic diagram of the connection between the stimulation electrode and the nerve provided by the present invention;

Figure 19 is a schematic diagram of a wireless power supply module provided by the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The embodiment of the invention discloses an implantable diaphragm pacemaker, comprising: an external controller, a wireless power supply module, two receivers and two stimulation electrodes; the external controller is electrically connected to the wireless power supply module; the wireless power supply module and the receiver The receiver is connected by radio to supply power to the receiver; each receiver is electrically connected to a stimulation electrode, and the two stimulation electrodes output bidirectional pulse current; the receiver communicates with the external controller wirelessly; the external controller transmits wireless signals through the wireless communication circuit To the receiver, the receiver controls the current amplitude and pulse interval output by the receiver through the microprocessor 2 and the two-way constant current stimulation circuit in the receiver according to the wireless signal. The controlled constant current acts on the stimulating electrode on the diaphragm muscle that stimulates the phrenic nerve, thereby stimulating the phrenic nerve to cause the diaphragm to contract, and the controlled constant current repeatedly stimulates the phrenic nerve in a cycle, which approximates the breathing movement that constitutes a physiological pattern.

In order to further optimize the above technical scheme, the receiver and stimulation electrode are implanted in the body, the stimulation electrode is located on the phrenic nerve, the receiver is implanted in the epidermis near the second rib of the thoracic cavity, and the stimulation electrode is electrically connected to the receiver; in the wireless power supply module The wireless power supply transmitter circuit of the is attached to the top of the skin where the receiver is located.

In order to further optimize the above technical solutions, the external controller includes a power management system, a wireless communication circuit, a wireless power supply control circuit, a voltage and current detection circuit, a human-computer interaction circuit, and a microprocessor one; the power management system includes a battery protection circuit, a battery Charging circuit, load switch circuit, step-down circuit one, main power supply switch, wireless power supply switch one and wireless power supply switch two; the human-computer interaction circuit controls the power supply through the load switch circuit and connects to the microprocessor one; the wireless communication circuit through the load switch The circuit controls the power supply and connects to the microprocessor one for wireless communication with the receiver; the wireless power supply power control circuit controls the power supply through the load switch circuit and is connected to the wireless power supply module, and the wireless power supply control circuit connects to the wireless power supply module through the silicone soft wire The coil drive circuit is connected, the wireless power supply control circuit is electrically connected to the battery charging and discharging circuit of the battery protection circuit; the microprocessor is connected to the voltage and current detection circuit through the load switch circuit; the step-down circuit is connected to the battery protection circuit and the load switch Circuit; the battery protection circuit and the charging circuit are connected to the power supply; the wireless power supply module is connected to the wireless power supply control circuit through the wireless power supply switch; the battery connected to the battery protection circuit is electrically connected to the main power supply switch, and the main power supply switch is electrically connected to the step-down circuit; The battery protection circuit is electrically connected to the battery charging circuit, the step-down circuit is electrically connected to the battery protection circuit, and the step-down circuit is electrically connected to the load switch circuit, the human-computer interaction circuit and the microprocessor;

The wireless power supply power control circuit includes a power supply control circuit one and a wireless power supply control circuit two. The load switch circuit is electrically connected to the wireless power supply control circuit one and the wireless power supply control circuit two; the wireless power supply control circuit one is through the wireless power supply switch one. Connected to the wireless power supply module, the second wireless power supply control circuit is connected to the wireless power supply module through the second wireless power supply switch; the first microprocessor judges whether the wireless power supply switch is closed, so as to realize the power supply of the wireless power supply power control circuit by the load switch circuit.

In order to further optimize the above technical solutions, the external controller is used to adjust the current amplitude, pulse interval and respiration frequency of the receiver; the range of breathing cycle is adjustable from 5-30 times/min, the range of current amplitude is adjustable from 0-10mA, and the pulse interval is adjustable. The range of 10-200ms is adjustable; the power management system is mainly used to control the charging and discharging of the battery, and to control the power supply and power off of each module; the wireless communication circuit mainly transfers the mutual communication between the microprocessor 1 and the receiver; the wireless power supply control circuit Limit the wireless transmitting power of the wireless power supply module to a certain range to limit the voltage received by the receiver. The transmitting coil of the wireless power supply module is used for wireless power supply; the voltage and current detection circuit is used to detect battery voltage and total current, and wireless power supply power If the current in the control circuit is found to be abnormal, including whether the transmitter coil of the wireless power supply module is in good contact with the external controller, the health of the battery, etc., the corresponding abnormal content will be prompted, and the protection program will be turned off if necessary; Device one controls and coordinates the work of the remaining circuits.

In order to further optimize the above technical solution, the receiver includes a rectifier circuit, a step-down circuit two, a wireless communication circuit, a two-way constant current stimulation circuit and a microprocessor two; the rectifier circuit is connected with a receiving coil, which is connected to the wireless power supply module by radio. ; The rectifier circuit is electrically connected with the step-down circuit two; the microprocessor two is electrically connected with the step-down circuit two, the wireless communication circuit and the two-way constant current stimulation circuit; the receiving coil receives the alternating current and transmits it to the rectifier circuit, and then transmits it to the step-down circuit. Second, perform the step-down processing, and finally power the receiver's microprocessor two and the two-way constant current stimulation circuit; the microprocessor two supplies power to the two-way constant current stimulation circuit; the wireless communication function module of the microprocessor two and the wireless controller of the external controller The communication circuit performs wireless communication; the bidirectional constant current stimulation circuit is connected to the stimulation electrode through the electrode connector. The receiver receives and executes the parameters set by the external controller. The rectifier circuit is used to rectify and filter the alternating current generated by the wireless power supply module induced by the receiving coil into direct current, and supply power to the step-down circuit two and the bidirectional constant current stimulation circuit; The second circuit is used to reduce the higher voltage after rectification to the voltage required by the second microprocessor and the two-way constant current stimulation circuit; the second microprocessor is used to execute various control modes; the two-way constant current stimulation circuit is used to control the magnitude of the stimulation current And current direction.

In order to further optimize the above technical solution, the wireless power supply module includes a wireless power supply transmitting circuit one and a wireless power supply transmitting circuit two, which are respectively wirelessly connected to the receiving coil of a receiver to supply energy; the wireless power supply transmitting circuit one and the wireless power supply transmitting circuit two are connected wirelessly. The configuration is the same, the first wireless power supply transmitter circuit includes a transmitter coil and a coil drive circuit; the transmitter coil is connected to the coil drive circuit. The coil drive circuit is electrically connected to the wireless power supply power control circuit through the wireless power supply switch; the coil drive circuit and the wireless power supply power control circuit are electrically connected through the silicone soft wire to realize the control of the external controller to the receiver's power supply; the wireless power supply transmitter circuit is wirelessly connected The power supply switch is connected with the wireless power supply control circuit one, the transmitting coil is wirelessly connected with the receiving coil in a receiver to realize the power supply to the receiver; the wireless power supply transmitting circuit two is connected with the wireless power supply control circuit two through the wireless power supply switch, The transmitting coil is wirelessly connected to the receiving coil in another receiver. The wireless charging between the receiver and the wireless power supply module is based on the principle of wireless electromagnetic induction. The wireless power supply module is jointly controlled by the wireless power supply switch in the external controller and the wireless power supply power control circuit. The wireless power supply control circuit is electrically connected to the wireless power supply module through a silicone soft wire. The microprocessor in the external controller controls the wireless power supply module. The transmission power of the power supply control circuit. When the passive switch is detected to be closed, the wireless power supply control circuit starts to work, thereby controlling the strength of the electromagnetic field generated by the transmitting coil in the wireless power supply module, limiting the induced voltage of the receiver, and realizing the wireless power supply module Provides wireless power to the receiver. The wireless power supply transmitter circuit in the wireless power supply module is attached to the top of the skin where the receiver is located. The transmitter coil of the wireless power supply transmitter circuit one and the receiver coil of a receiver are located on both sides of the skin. The transmitter coil of the wireless power supply transmitter circuit two is opposite to the other The receiving coils of a receiver are located on opposite sides of the skin.

In order to further optimize the above technical scheme, the receiver is disc-shaped and insulated with epoxy resin potting. Since the receiver is implanted near the clavicle and rib skin, the wireless power supply module is pasted on the top of the receiver skin with medical tape. The skin and muscle tissue are thin. The distance between the receiver and the wireless power transmission circuit of the wireless power supply module is 1～ 2cm, so it is conducive to wireless charging, reducing power transmission distance and power consumption during power transmission.

In order to further optimize the above technical scheme, the bidirectional constant current stimulation circuit is equipped with an analog switch chip to generate bidirectional stimulation current, and use two stimulation electrodes to achieve bidirectional stimulation with two electrodes. The use of bidirectional stimulation can avoid affecting other nerves or muscles other than the phrenic nerve, and also avoid phrenic nerve fatigue. Using double electrodes can output two opposite electrical signals. Through the external controller, the respiratory frequency, intensity, pulse width and other parameters of each signal can be set and adjusted, and then the receiver can be controlled by the wireless power supply module to follow the set parameters Electric pulses of a certain width and amplitude are generated, which are finally released through double electrodes to stimulate the phrenic nerve and realize the control of breathing.

In order to further optimize the above technical solution, the first microprocessor communicates with the second microprocessor through a wireless communication circuit.

In order to further optimize the above technical solution, the human-computer interaction circuit includes a display circuit, an adjustment circuit and a breathing indication circuit; the display circuit, the adjustment circuit and the breathing indication circuit are connected to the microprocessor when working, and the display circuit is connected to the load switch circuit.

In order to further optimize the above technical solution, the main power switch and the wireless power switch respectively control the power supply of the entire circuit and the power supply of the wireless power supply module; communicate with the microprocessor through the external interrupt detection method.

In order to further optimize the above technical solutions, the microprocessor one and the microprocessor two use MSP430 series low-power single-chip microcomputers to realize the control and data transmission of each circuit; the step-down circuit in the power management system uses the LM536255 series chip, which can achieve high efficiency and low power consumption. The load switch uses the TSP22810 chip, its turn-off current is 500nA, which can reduce the static power consumption; the constant current circuit is composed of a constant current source circuit based on an operational amplifier, which can output a maximum of 10mA current; the wireless communication circuit uses the N52810 chip, which can be realized Two-way communication between microprocessor 1 and microprocessor 2; the main control chip U10 of the wireless power supply power control circuit uses the LT3592 chip; the constant current stimulation circuit in the receiver uses DA to generate an adjustable voltage signal, which is generated by the constant current stimulation circuit Adjustable constant current. Two sets of constant current source circuits form a bidirectional stimulation circuit. The stimulation electrodes are divided into electrode 1 and electrode 2. There are two situations in the stimulation process. First, electrode 1 outputs a high level, and electrode 2 outputs a low level. At this moment, the current flows from the electrode 1 to the electrode 2; in another case, the electrode 2 outputs a high level, and the electrode 1 outputs a low level. At this time, the current flows from the electrode 2 to the electrode 1.

In order to further optimize the above technical solution, the bidirectional constant current stimulation circuit includes an operational amplifier TLV2171, analog switches ADG721 and DA AD5601; DA is connected to an analog switch, and an operational amplifier is connected through the analog switch, and each operational amplifier is connected to a stimulation electrode. When the microprocessor 2 receives the set current value sent by the external controller, it sets the output voltage of DA according to the current value, then transmits it to the operational amplifier circuit through the analog switch, and converts it into a constant current output to the stimulation electrode through the operational amplifier circuit.

Example

(1) Wireless communication workflow:

S11: As soon as the microprocessor turns on the load switch connected to the wireless communication circuit, it supplies power to the wireless communication circuit, and waits for the initialization of the wireless communication circuit to be completed;

S12: Once the microprocessor sends an instruction to the wireless communication circuit through the serial port, the wireless communication circuit sends the instruction to the receiver. The receiver receives the instruction, and the second microprocessor confirms whether the instruction is correct. If the instruction is correct, it stores the data in the Flash and executes it and feeds it back to the external controller;

S13: After the wireless communication circuit receives the instruction feedback from the receiver, it forwards it to the microprocessor one through the serial port;

S14: Once the microprocessor confirms that the feedback command is correct, the load switch is turned off and the wireless communication circuit is powered off.

(2) Display circuit work flow:

S21: When adjusting the parameters, an interrupt signal is generated to the microprocessor 1, and the microprocessor opens the load switch connected to the human-computer interaction circuit to supply power to the display screen;

S22: After the initialization of the display screen is completed, the parameters will be displayed on the display screen. If no parameter changes within 5 seconds, the load switch will be turned off and the display screen will be powered off.

The receiver generates a constant current working process:

S31: The second microprocessor in the receiver reads the data in Flash (including current intensity, pulse width, and breathing cycle);

S32: Send the law of current intensity, pulse width and breathing cycle to the DA chip to generate a corresponding voltage signal V1 (mV);

S33: The constant current stimulation circuit generates a corresponding constant current signal according to the voltage signal in S32; the current output current (mA) = V1/R, where R is the sampling resistance value in the constant current circuit;

S34: The second microprocessor switches the input signals transmitted to the 2-way constant current circuit of the operational amplifier circuit through the analog switch, and changes the direction of the current applied to the two stimulation electrodes to complete the bidirectional current stimulation.

(3) Two-way communication process:

The wireless communication circuit includes a transmitter module and a receiver module. The controllers of the transmitter module and the receiver module are composed of a Bluetooth chip. The chip contains a controller. The transmitter module and the receiver module are controlled by the controller, so that the microprocessor in the external controller is one The connected wireless communication module communicates with the second microprocessor in the receiver to realize the information interaction between the first microprocessor and the second microprocessor. The set information is transmitted to the wireless communication module, and the wireless communication module forwards the information to the second microprocessor. The second microprocessor confirms the received user information. If it determines that the information is correct, it will feed back the correct instruction to the wireless communication module, and the wireless communication module will This instruction is forwarded to microprocessor one. Once the microprocessor determines that the wireless receiving module receives the information, it turns off the power of the wireless communication module and completes a parameter setting.

Microprocessing one sends the data to the second microprocessor, and the second microprocessor judges and reads it. If the data frame length is correct and the value is within a reasonable range, the data is judged to be correct, and the response data is returned. Whether the processor 2 successfully receives the data, if the reception is successful, then close the wireless communication module, if the reception is unsuccessful, then retransmit. If the number of re-transmissions is greater than 100, it is judged as a failure, displayed and alarmed.

The wireless communication circuit uses the Nordic nRF51822 chip, which contains a 32-bit Cortex-M0 core CPU and Flash, which is characterized by ultra-low power consumption in the field of wireless communication.

(5) Power management system:

The power supply voltage of the encoder and load switch used to adjust the parameters is 3.3V, and the encoder is used to adjust the stimulation current parameters; the current detection voltage is 5V; the single-chip analog acquisition power supply requires a very accurate 3.3V voltage, and at the same time, it must have a low static power. Therefore, the Buck chip is used to efficiently step down the battery voltage to 5V, and then the 5V is used as an input to convert it to a high-precision 3.3V through a voltage reference chip (ie, a high-precision voltage regulator chip). At the same time, it must have low static power consumption. Each system has a separate load switch that works intermittently to achieve extremely low static power consumption.

The voltage regulator of the step-down circuit 1 needs to reduce the power supply 12V to the 5V required by the chip. This voltage difference is very large. If the LDO linear regulator is used, although the ripple is small, it will generate a large energy loss and heat. Reduce system efficiency. Therefore, a DC-DC converter is used for step-down. You can choose the LM53635 chip from Texas Instruments. The LM53635-Q1 synchronous buck regulator is optimized for medical applications and can provide 5V, 3.3V or adjustable output voltage. The chip can adjust the output voltage range from 3.3V to 18V, and the switching frequency is fixed at 2.1MHz. The upper limit of the input voltage range is as high as 36V, and the transient tolerance can reach 42V. At the same time, the chip has built-in filtering and other functions to save surrounding circuit space.

The power supply regulator chip uses the LT1117 device, which is an adjustable 3-terminal positive voltage regulator.

(6) Principle of wireless charging

The receiver is a low-power product and only requires low power, so it cannot be powered by the principle of series resonance. The present invention uses parallel resonance to supply power, and the transmitter coil of the wireless power supply module and the receiver coil of the receiver are set as With the same resonance frequency, power transmission with low static power consumption can be completed. The main energy loss of parallel resonance lies in the loss of capacitors and inductors, so low-loss passive components are selected, the capacitor material is NP0, the inductance material is high-frequency low-loss inductors, and high-frequency low-loss inductors are used.

(7) Power control principle:

Because parallel resonance is current resonance, the voltage between the transmitting and receiving is very high. If the power is not limited, the voltage at the receiving end can easily reach hundreds of volts, which can damage the receiving step-down circuit (withstand voltage of 36V), so the transmitting end needs power Control to achieve the receiving voltage in the safe voltage range. In addition, the distance between the receiving terminal voltage and the coil transmitter has a great influence on the receiving voltage. If it is not controlled, the receiving terminal voltage will change greatly, so the constant current power supply method is used to reduce the distance. The impact on the voltage receiving end, the voltage is controlled below 36V.

(8) In the external controller, the microprocessor one uses the Arm Cortex-M0+ core MSP430FRx series of ultra-low power 16-bit single-chip microcomputers. The internal resources of the chip mainly include 256KB FRAM, 6 16-bit timers, 7 advanced timers, 6 DMA controllers, 8 groups of SPI, 5 groups of IIC, 5 serial ports, 1 12-bit ADC and 9 groups of general-purpose IO ports; its maximum operating frequency can reach 16MHz, and the current consumption in working mode is 118μA/MHz. The single-chip microcomputer communicates with the wireless communication circuit through a serial port.

(9) The voltage and current detection circuit uses the INA199A3 chip. The INA199 series voltage output and current shunt monitors (also called current sensing amplifiers) are often used for overcurrent protection, precision current measurement optimized for the system, or closed-loop feedback circuits.

(10) The receiver's micro-processing two uses Nordic nRF52810 chip, which is an ultra-low-power ultra-low-power chip that integrates Bluetooth and MCU. It has 64MHz, 32-bit ARM Cortex M4MCU, and maintains the deployment of LE secure connections and 2Mbps data processing function. This Bluetooth chip integrates the second microprocessor and the wireless receiving circuit in the wireless communication circuit, which reduces the use space and reduces the overall volume of the receiver. The receiving coil supplies power to the rectifier circuit and the step-down circuit through the principle of electromagnetic induction, so that the step-down circuit 2 outputs a stable 3.3V voltage to the microprocessor 2 to ensure that the microprocessor 2 can work normally, and then realize the external controller through the wireless communication circuit Communication with the receiver of the respiratory cycle, current intensity, and pulse width parameters.

Receiver output constant current signal process:

The wireless communication circuit in the external controller is used as the transmitter, and the wireless communication circuit in the receiver is used as the receiver. The transmitter sends the correct instructions to the receiver, and then controls the second microprocessor to output signals to the digital-to-analog converter to make the digital-to-analog conversion. The device outputs an analog voltage signal, while the second microprocessor controls the analog switch, and outputs a stable voltage to the phrenic nerve through a bidirectional stimulation circuit constructed using the H-bridge principle.

Figure 2 shows the schematic diagram of the battery protection circuit and the battery charging circuit. The battery protection circuit is composed of the battery and ultra-low power battery protection bq77915 chip, which realizes the protection of voltage, current and temperature, as well as battery cell balance. The positive power supply is connected to bq77915 The VC3-VC5 pins of the chip U1, the negative pole is connected to the VC0, VSS, and SRP pins of the bq77915 chip U1.

Figure 3 shows the schematic diagram of the battery charging circuit. The LTM8062 chip is used. In addition, the battery protection circuit is electrically connected to the battery charging circuit to realize a complete power supply system. The BAT_1-BAT_12 pins of the LTM8062 chip U2 are connected to the positive pole of the power supply, and the negative pole is connected to U2. The ground terminal.

Figure 4 is the schematic diagram of the step-down circuit. The step-down routing chip is composed of LM53635, LT1117, and REF3433. Its function is to convert the 12V voltage to 5V and 3.3V. The 5V voltage is the current detection circuit and the chip in the step-down circuit. REF3433, LT1117 power supply, 3.3V voltage for display circuit, wireless communication circuit, regulating circuit, breathing indicator circuit, microprocessor 1 power supply. The AVIN, PVIN1 and PVIN2 pins of U4 formed by the chip LM53635 are connected to the positive electrode of the battery.

Figure 5 is a schematic diagram of the load switch circuit, which is responsible for the on and off of the display circuit, the wireless communication circuit, the wireless power supply control circuit one, the wireless power supply power control circuit two, and the voltage and current detection circuit. The chips used in these switch circuits are all TPS22810, which is equivalent to a switch.

Figure 6 is the schematic diagram of the voltage and current detection circuit. The voltage detection is realized by the resistor divider. The current detection is converted into voltage by the chip INA199. Is the current working normally? The ADC_1 port is connected to the ADC_1 port of the P1.3 pin of the microprocessor, and the ADC_0 port is connected to the ADC_0 port of the P1.2 pin of the microprocessor.

Figure 7 is a schematic diagram of the human-computer interaction circuit. The display circuit uses an OLED screen, and the adjustment circuit uses 3 low-power encoders to complete the user adjustment judgment. The breathing indicator circuit is completed by 2 light-emitting diodes, and the light-emitting diode is on to indicate Inspiratory state, the light-emitting diode is on to indicate exhalation state;

Figure 8 is a schematic diagram of the wireless power supply control circuit. The chip used is LT3592, which controls the current and voltage output by the circuit to prevent the receiving coil voltage from being too high; the Vbat_2 port of U13 is connected to the VOUT of U6 in the load switch circuit Pin, the Vbat_2 port of U14 is connected to the VOUT pin of U7 in the load switch circuit.

Figure 9 is a schematic diagram of the wireless communication circuit. The wireless communication circuit uses the chip N52810 to complete the information interaction through the P3 program download port and the P2 program download port of the micro-processing one to realize the functions of wireless data sending and receiving;

Figure 10 shows the wireless power supply transmitting circuit, which is composed of a coil drive circuit and a transmitting coil to complete the wireless transmission of electrical energy. The chip used is UCC28089; it is connected to the Vbat_2 port that provides electrical energy.

Figure 11 is a schematic diagram of wireless power supply connection, showing the wireless power transmission of the transmitter coil and the receiver coil;

Figure 12 is a schematic diagram of the connection of the main power switch, showing that the battery supplies power to the entire system circuit through the main power switch;

Figure 13 is a schematic diagram of a microprocessor, showing the connection relationship between the microprocessor and other circuits;

Figure 14 is a schematic diagram of the structure of the circuit included in the receiver. The receiver includes a rectifier circuit, a step-down circuit, a bidirectional constant current stimulation circuit, and a second microprocessor.

Figure 15 is a schematic diagram of the rectifier circuit and the step-down circuit. The rectifier circuit includes a receiving coil. The receiving coil converts the AC voltage into a DC voltage through the rectifier bridge and outputs it to the step-down circuit 2. The high voltage is converted to 3.3V to supply power to the second microprocessor and the bidirectional constant current stimulation circuit. The chip used in the second step-down circuit is LMZM23601. The parallel connection point of the capacitors C63-C66 of the second step-down circuit is connected to the rectifier bridge D6 in the rectifier circuit; the VCC3V3 port of the second step-down circuit U18 is connected to the VDD pin of the second microprocessor N52810QFN32 chip.

Figure 16 is a schematic diagram of the second microprocessor. The second microprocessor is a microprocessor with wireless communication function. Its model is N52810, which controls the magnitude and direction of the output current to achieve communication with the bidirectional constant current stimulation circuit. The coil L12 is grounded through the wireless communication antenna, the wireless communication antenna and the wireless communication circuit perform wireless communication, and the P4 interface is the program download port.

Figure 17 shows the bidirectional constant current stimulation circuit, which uses the chip AD5621, the chip ADG721 and two TLV2171 operational amplifiers to output bidirectional current to the stimulation electrodes. The SCLK and SDIN pins of the U22 chip AD5621 are connected to the P0.05 and P0.06 pins of the second microprocessor; the IN1 and IN2 pins of the U24 analog switch chip ADG721 are connected to the P0.09 and P0.10 pins of the second microprocessor; The output pin 1 of the U20A operational amplifier TLV2171 is connected to the stimulation electrode through the electrode connector, and the output pin 7 of the U20B operational amplifier TLV2171 is connected to the stimulation electrode through the electrode connector.

Figure 18 is a schematic diagram of the connection between the stimulation electrode and the nerve, and double stimulation electrodes are placed on the phrenic nerve.

Figure 19 is a schematic diagram of a wireless power supply module. The wireless power supply module connects the wireless power supply transmitter circuit and the wireless power supply power control circuit through a wireless power supply switch.

Beneficial effects:

1) The precise control of the output current is achieved by adding a constant current stimulation circuit in the receiver, eliminating

The relative position of the coil in the wireless power supply module and the coil in the receiver within a certain range affects the stimulation current

Impact.

2) A power management system is set in the external controller, and a load switch circuit is used to achieve intermittent power supply

Control to reduce standby power consumption.

3) The wireless communication module in the external controller and the wireless communication module in the receiver are both two-way communication

Information, can send and receive data to each other, and then realize data analysis and judge the correctness of the data (including

Data packet loss and external data interference, etc.), increase the stability of the receiver.

The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this document, but should conform to the widest scope consistent with the principles and novel features disclosed in this document.

Claims

An implantable diaphragm pacemaker, which is characterized by comprising: an external controller, a wireless power supply module, two receivers and two stimulation electrodes; the external controller is electrically connected to the wireless power supply module; the wireless The power supply module is wirelessly connected to the receiver to transmit electrical energy to supply power to the receiver; each of the receivers is electrically connected to one of the stimulation electrodes, and the two stimulation electrodes output bidirectional pulse currents; the receivers Perform wireless communication with the external controller.
The implantable diaphragm pacemaker according to claim 1, wherein the external controller includes a power management system, a wireless communication circuit, a wireless power supply control circuit, a voltage and current detection circuit, and a human-computer interaction circuit And microprocessor one;

The power management system includes a battery protection circuit, a battery charging circuit, a load switch circuit, a step-down circuit, a main power supply switch and a wireless power supply switch; the human-computer interaction circuit controls the power supply through the load switch circuit, and is connected to the Microprocessor one; the wireless communication circuit controls power supply through the load switch circuit, and is connected to the microprocessor one for wireless communication with the receiver; the wireless power supply power control circuit passes through the load switch circuit Control power supply and connect to the wireless power supply module; the microprocessor is connected to the voltage and current detection circuit through the load switch circuit; the step-down circuit is connected to the battery protection circuit and the load Switch circuit; the battery protection circuit and the charging circuit are connected to a power source; the wireless power supply module is connected to the wireless power supply power control circuit through the wireless power supply switch; the battery connected to the battery protection circuit is connected to the power supply The switch is electrically connected, the main power supply switch is electrically connected to the step-down circuit; the battery protection circuit is electrically connected to the battery charging circuit, and the step-down circuit is electrically connected to the battery protection circuit. A step-down circuit is electrically connected to the load switch circuit, the human-computer interaction circuit and the microprocessor;

The wireless power supply control circuit is electrically connected with the load switch circuit; the wireless power supply control circuit is connected with the wireless power supply module through the wireless power supply switch.
The implantable diaphragm pacemaker according to claim 2, wherein the receiver includes a rectifier circuit, a step-down circuit two, a microprocessor two and a bidirectional constant current stimulation circuit; the rectifier circuit is connected and arranged There is a receiving coil, which is wirelessly connected to the wireless power supply module through the receiving coil, and the rectifier circuit is electrically connected to the second step-down circuit; the second microprocessor is connected to the second step-down circuit and the two-way constant The current stimulation circuit is electrically connected; the wireless communication function module of the second microprocessor performs wireless communication with the wireless communication circuit in the external controller; the two-way constant current stimulation circuit is connected to the stimulation electrode through an electrode connector .
The implantable diaphragm pacemaker according to claim 3, wherein the wireless power supply module comprises a wireless power supply transmitting circuit one and a wireless power supply transmitting circuit two, which are respectively connected to the receiving coil of the receiver. Wireless connection for power supply; the first wireless power supply transmitter circuit has the same configuration as the second wireless power supply transmitter circuit, the first wireless power supply transmitter circuit includes a transmitter coil and a coil drive circuit; the transmitter coil is connected to the coil driver Circuit; The coil drive circuit is electrically connected to the wireless power supply control circuit through a wireless power supply switch.
The implantable diaphragm pacemaker according to claim 3, wherein the receiver is disc-shaped and insulated by epoxy resin potting.
The implantable diaphragm pacemaker according to claim 1, wherein the bidirectional constant current stimulation circuit is provided with an analog switch chip to generate a bidirectional stimulation current, and the two stimulation electrodes are used to achieve bidirectional stimulation with two electrodes .
The implantable diaphragm pacemaker of claim 3, wherein the first microprocessor communicates with the second microprocessor through the wireless communication circuit.
The implantable diaphragm pacemaker according to claim 2, wherein the human-computer interaction circuit includes a display circuit, an adjustment circuit, and a breathing indication circuit; the display circuit, the adjustment circuit, and the breathing The indicating circuit is connected to the microprocessor, and the display circuit is connected to the load switch circuit.