Multi-point wireless monitoring system for ischemic heart

Abstract

The invention discloses a multi-point wireless monitoring system for an ischemic heart, and relates to the technical field of medical signal processing, the system comprises an adhesive conductive layer hydrogel patch, a sensor layer, a wireless monitoring system implanted subcutaneously, and a display terminal; the wireless monitoring system comprises a signal processing module, a power management module, a voltage management module, a wireless electric energy receiving module and a Bluetooth signal transmission module; the current change of the drain electrode is detected through the sensor layer so as to monitor the contractility conditions of different sites of the ischemic heart; the adhesive conductive layer hydrogel patch provides adhesive force between the sensor layer and the cardiac muscle; the voltage management module outputs different grid voltage and source voltage to the sensor layer; the signal processing module processes the current change of the drain electrode, and then the Bluetooth signal transmission module processes the current change and sends the current change to a display terminal. According to the invention, the wireless monitoring system can be implanted in vivo, and real-time and continuous monitoring of the contractility condition of ischemic myocardium is realized.

Description

Technical Field

[0001] The invention relates to the technical field of medical signal processing, and in particular to a multi-point wireless monitoring system for ischemic heart. Background Art

[0002] Cardiovascular disease is the leading cause of death in humans, and one of its prominent features is myocardial ischemia. Severe myocardial ischemia can lead to arrhythmias and decreased myocardial contractility caused by fibrosis. Therefore, real-time monitoring of mechanical physiological signals of ischemic myocardium is particularly important. Monitoring mechanical physiological signals such as relaxation, contraction amplitude and rhythm of ischemic myocardium can reflect myocardial contractility and pumping function, and has important applications in the diagnosis of cardiovascular diseases. However, the existing technology has the following problems: 1. For the signal output of the pressure sensor for monitoring heart beats, most of them can only rely on external multimeters or oscilloscopes for detection, and there is no microcircuit system that can be implanted in the body to output the sensor signal.

[0003] 2. For hydrogel sensors for ischemic heart monitoring, the force applied to the hydrogel changes with the heart beating, and the magnitude of the force is monitored by using changes in parameters such as the resistance or capacitance of the entire hydrogel; therefore, the hydrogel sensor can only monitor the magnitude of force in a large range of the area covered by the hydrogel, and cannot accurately monitor the magnitude of force at each point in the heart.

[0004] Therefore, there is an urgent need for a solution that can accurately monitor the cardiac contractility at various points in the heart. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-point wireless monitoring system for ischemic heart. The wireless monitoring system is implanted in the body to monitor the contractility of multiple points of the ischemic myocardium in real time and continuously.

[0006] To achieve the above object, the present invention provides the following solutions: An ischemic heart multi-point wireless monitoring system, comprising an adhesive conductive layer hydrogel patch, a sensor layer, a wireless monitoring system, and a display terminal; The adhesive conductive layer hydrogel patch is used to adhere the sensor layer to the surface of the ischemic heart through the adhesive conductive layer hydrogel on the surface of the patch; The sensor layer is a FET type sensor layer made of flexible electrodes, which is used to monitor the contraction force of different sites of the ischemic heart by detecting the current change of the drain electrode, and transmit it to the wireless monitoring system; The wireless monitoring system includes a signal processing module, a power management module, a voltage management module, a wireless power receiving module, and a Bluetooth signal transmission module. The wireless monitoring system is implanted subcutaneously, and the sensor layer is connected to the wireless monitoring system via a flexible wire. The voltage management module is used to output different gate voltages and source voltages to the sensor layer; the signal processing module is used to convert the received drain current changes into voltage and perform signal amplification processing on the voltage; the Bluetooth signal transmission module is used to perform analog-to-digital conversion on the amplified voltage to obtain information of different monitoring sites and send it to the display terminal; the wireless power receiving module is used to receive the electric energy transmitted by the wireless power transmitting device outside the human body using the principle of electromagnetic induction, and is connected to the power management module, and the power management module is used to power the signal processing module, the power management module, and the Bluetooth signal transmission module.

[0007] Furthermore, the preparation method of the adhesive conductive layer hydrogel is: The amino-modified carbon nanotubes are ultrasonically mixed in a buffer solution, and then an appropriate amount of dopamine solution is added to physically coat the surface of the carbon nanotubes by in-situ polymerization of dopamine to generate polydopamine. Then, acrylic acid solution, a crosslinker and an initiator are added to polymerize under appropriate conditions to obtain an adhesive conductive layer hydrogel.

[0008] Furthermore, the cross-linking agent is N,N-methylenebisacrylamide, the initiator is phenyl (2,4,6-trimethylbenzoyl) lithium phosphate, and the buffer is Tris buffer with a pH of 8.5.

[0009] Furthermore, the amount of the amino-modified carbon nanotubes is 30-60 mg, the amount of the buffer solution is 7 ml, the ultrasonic mixing time is 1-2 h, the amount of dopamine is 8-10 mg, the amount of the acrylic acid solution is 3 ml, the amount of the cross-linking agent is 6-10 mg, and the amount of the initiator is 20-30 mg.

[0010] Furthermore, the suitable condition is irradiation with ultraviolet light.

[0011] Furthermore, the sensor layer is prepared according to the following method: S1. Making flexible electrodes using an FPC flexible circuit board: the FPC flexible circuit board includes a bottom PI film, a top PI film, and an electrode arranged between the bottom PI film and the top PI film, the electrode including a source electrode, a drain electrode, and a gate electrode, and the top PI film is removed from the electrode portion corresponding to each monitoring site; S2. Making a sensor layer using the flexible electrode: making source, drain and gate lines on the same plane, then forming a graphene channel between the source and drain by wet transfer of graphene, and finally forming an air layer between the gate and the drain and source at each monitoring site by folding it in half to obtain the sensor layer.

[0012] Furthermore, there are multiple monitoring sites.

[0013] Furthermore, the Bluetooth signal transmission module uses the nrf52832 chip, and the display terminal is a mobile phone APP.

[0014] Furthermore, the wireless power receiving module includes a receiving coil implanted in the body, the receiving coil is used to couple and receive electromagnetic waves sent by the transmitting coil of the wireless power transmitting device outside the human body, and convert them into a 5V voltage output. The power management module converts the received 5V voltage into a 3.3V voltage to power the wireless monitoring system.

[0015] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the present invention provides a multi-point wireless monitoring system for ischemic heart, which provides adhesion force for the sensor through the adhesion of the conductive layer patch, so that it adheres to the surface of the heart to monitor the signal; it can monitor the contraction force of multiple sites of the heart within the patch range in real time and continuously. The sensor layer prepared by the present invention can be completed by simply folding it in half after wet transfer of graphene, which is simple to make and low in cost; the wireless monitoring circuit made by the present invention is small in size, and can be implanted in the body after packaging, and can achieve real-time monitoring; the present invention uses a wireless power supply module to power the system, avoiding the trouble of frequent battery replacement after the battery power is exhausted. In addition, the patch composed of adhesive hydrogel and sensor can not only be implanted in the body for real-time and continuous monitoring of multiple points, but also can be directly attached to the surface of the isolated heart to measure the contraction force of the isolated heart. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 This is a distribution diagram of the sensor electrode circuit of an embodiment of the present invention, where the yellow area is the electrode circuit; the outer white line is the sensor shape, and the sensor shape is cut out according to the white line; the rectangular electrodes on the left and right sides are the areas connected to the wireless monitoring circuit; Figure 2 This is an enlarged view of the monitoring part of the sensor of the embodiment of the present invention. In the figure, each monitoring site is composed of a source electrode and a drain electrode. The lower electrode of each monitoring site is the source electrode, the upper electrode is the drain electrode, and the middle gray area is the graphene channel; the three electrodes on the right are gate electrodes; Figure 3 This is a longitudinal cross-sectional view of each monitoring site formed after folding of an embodiment of the present invention. In the figure, the gate is at the top, the source and drain are at the bottom, the graphene channel is in the middle, and the air layer in the middle is formed by folding the flexible electrodes on both sides; Figure 4 A schematic diagram of the structure of a wireless monitoring system in an embodiment of the present invention; Figure 5 The system structure diagram of the ischemic heart multi-point wireless monitoring system of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The purpose of the present invention is to provide a multi-point wireless monitoring system for ischemic heart. By implanting the wireless monitoring system into the body, the contractility of multiple points of the heart can be monitored in real time and continuously.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, an ischemic heart multi-point wireless monitoring system provided by an embodiment of the present invention includes an adhesive conductive layer hydrogel patch, a sensor layer, a wireless monitoring system, and a display terminal; The adhesive conductive layer hydrogel patch is used to adhere the sensor layer to the surface of the ischemic myocardium through the adhesive conductive layer hydrogel on its surface; The sensor layer is a FET type sensor layer made of flexible electrodes, which is used to monitor the contraction force of different monitoring sites of the ischemic heart by detecting the current change of the drain electrode, and transmit it to the wireless monitoring system; The wireless monitoring system includes a signal processing module, a power management module, a voltage management module, a wireless power receiving module, and a Bluetooth signal transmission module. The wireless monitoring system is implanted subcutaneously, and the sensor layer is connected to the wireless monitoring system via a flexible wire. The voltage management module is used to output different gate voltages and source voltages to the sensor layer; the signal processing module is used to convert the received drain current changes into voltage and perform signal amplification processing on the voltage; the Bluetooth signal transmission module is used to perform analog-to-digital conversion on the amplified voltage to obtain information of different monitoring sites, and send it to the display terminal via Bluetooth; the wireless power receiving module is used to receive electrical energy transmitted by a wireless power transmitting device outside the human body using the principle of electromagnetic induction, and is connected to the power management module, and the power management module supplies power to the signal processing module, the voltage management module, and the Bluetooth signal transmission module.

[0022] In this embodiment, Figure 2 As shown, there are 8 monitoring sites, so that the multi-point contractility of the heart at 8 different sites of the heart within the patch range can be monitored, so as to more accurately judge the ischemic heart repair status.

[0023] In this embodiment, the CPU of the Bluetooth signal transmission module is an nrf52832 chip, and the display terminal is a mobile phone APP.

[0024] In this embodiment, the wireless power receiving module uses the principle of electromagnetic induction. The wireless power receiving module includes a receiving coil implanted in the body. The receiving coil is used to couple and receive electromagnetic waves sent by the transmitting coil of the wireless power transmitting device outside the human body, and convert them into a 5V voltage output. The power management module converts the received 5V voltage into a 3.3V voltage to power the wireless monitoring system. The power management module converts the 5V voltage received from the wireless power receiving module into a 3.3V voltage to power the Bluetooth signal transmission module.

[0025] In this embodiment, the wireless monitoring system uses AD software to design a circuit diagram, connects the sensor monitoring signal with the circuit, and the printed circuit board (PCB) of the circuit part is encapsulated with polydimethylsiloxane (PDMS) and implanted into the body. The nrf52832 chip on the circuit transmits the sensor signal wirelessly.

[0026] In a further embodiment, the preparation method of the adhesive conductive layer hydrogel is: 30 mg of amino-modified carbon nanotubes were mixed ultrasonically in 7 ml of Tris buffer (PH=8.5) for 1 hour, and then 9 mg of dopamine was added. The carbon nanotube surface was physically coated with polydopamine by in situ polymerization of dopamine to provide viscosity and conductivity to the hydrogel. Then 3 ml of acrylic acid solution, 6 mg of N,N-methylenebisacrylamide (BIS) and 25 mg of phenyl (2,4,6-trimethylbenzoyl) lithium phosphate (LAP) were added and polymerized under ultraviolet light to produce an adhesive conductive layer hydrogel. The adhesion is used to adhere the sensor to the surface of the ischemic heart to provide a stable signal monitoring environment, and the conductivity provides suitable conductivity for the ischemic heart myocardial tissue.

[0027] In a further embodiment, Figure 2-4 As shown, the sensor layer is prepared according to the following method: S1. Making flexible electrodes using FPC flexible circuit boards: The FPC flexible circuit board includes a bottom PI film, a top PI film, and electrodes arranged between the bottom PI film and the top PI film, wherein the electrodes include a source electrode, a drain electrode, and a gate electrode, and the top PI film is removed from the electrode portion corresponding to each monitoring site; since the thickness of the film is greater than the thickness of the electrode, the top PI film can be partially removed from each monitoring site; S2. Making a sensor layer using the flexible electrode: making a source, a drain and a gate line on the same plane, then forming a graphene channel between the source and the drain by wet transfer of graphene, and finally folding it in half to obtain a sensor. After folding, an air layer is formed between the gate and the drain and the source at each monitoring point. The air layer is compressed to different degrees by applying different forces to the monitoring points, and the capacitance between the gate and the source and the drain changes. The voltage applied to the gate and the source remains unchanged, and the contraction force is monitored by monitoring the current change of the drain.

[0028] Application in SD rat heart model: First, assemble the parts after they are made, adhere the conductive patch to the flexible sensor monitoring part, and connect the sensor signal export part to the wireless circuit part; after the SD rat heart model is constructed, the conductive patch and the sensor monitoring part are implanted on the surface of the ischemic heart, and the wireless circuit part is implanted under the skin. The sensor and the wireless circuit are transmitted through the ribs using flexible wires. Since the wireless circuit adopts the principle of wireless power supply, a wireless power supply coil is placed at the implantation site of the wireless circuit in the rat, and the receiving coil in the circuit receives energy to power the system. The signals monitored by the sensor are collected, and the collected information includes the information of the 8 monitoring sites on the sensor. A rainbow map real-time display software is made using the LabVIEW development environment to more vividly observe the stress conditions of each point.

[0029] In summary, the ischemic heart multi-point wireless monitoring system provided by the present invention can realize real-time and continuous monitoring of the contractility of multiple points of the heart within the patch range by implanting the wireless monitoring system into the body.

[0030] The remaining technical features in this embodiment can be flexibly selected by those skilled in the art according to actual conditions to meet different specific practical needs. However, it is obvious to those skilled in the art that it is not necessary to adopt these specific details to implement the present invention. In other examples, in order to avoid confusing the present invention, the well-known components, structures or parts are not specifically described, which are all within the technical protection scope defined by the technical solution claimed for protection in the claims of the present invention.

[0031] Modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the scope of protection of the claims attached to the present invention. In the above description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details are not necessary to practice the present invention. In other examples, in order to avoid confusing the present invention, well-known technologies, such as specific construction details, operating conditions and other technical conditions, are not specifically described.

[0032] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A multi-point wireless monitoring system for ischemic heart, characterized in that: It includes an adhesive conductive layer hydrogel patch, a sensor layer, a wireless monitoring system, and a display terminal; The adhesive conductive layer hydrogel patch is used to adhere the sensor layer to the surface of the ischemic heart through the adhesive conductive layer hydrogel on the surface of the patch; The sensor layer is a FET type sensor layer made of flexible electrodes, which is used to monitor the contraction force of different sites of the ischemic heart by detecting the current change of the drain electrode and transmit it to the wireless monitoring system; The wireless monitoring system includes a signal processing module, a power management module, a voltage management module, a wireless power receiving module, and a Bluetooth signal transmission module. The wireless monitoring system is implanted subcutaneously, and the sensor layer is connected to the wireless monitoring system via a flexible wire. The voltage management module is used to output different gate voltages and source voltages to the sensor layer; the signal processing module is used to convert the received drain current change into a voltage and perform signal amplification processing on the voltage; The Bluetooth signal transmission module is used to perform analog-to-digital conversion on the amplified voltage to obtain information of different monitoring sites and send it to the display terminal; the wireless power receiving module is used to receive the electrical energy transmitted by the wireless power transmitting device outside the human body using the principle of electromagnetic induction, and is connected to the power management module, and the power management module is used to power the signal processing module, the power management module, and the Bluetooth signal transmission module.

2. The multi-point wireless monitoring system for ischemic heart according to claim 1, characterized in that: The preparation method of the adhesive conductive layer hydrogel is: The amino-modified carbon nanotubes are ultrasonically mixed in a buffer solution, and then an appropriate amount of dopamine solution is added to physically coat the surface of the carbon nanotubes by in-situ polymerization of dopamine to generate polydopamine. Then, acrylic acid solution, a crosslinker and an initiator are added to polymerize under appropriate conditions to obtain an adhesive conductive layer hydrogel.

3. The multi-point wireless monitoring system for ischemic heart according to claim 2, characterized in that: The cross-linking agent is N,N-methylenebisacrylamide, the initiator is phenyl (2,4,6-trimethylbenzoyl) lithium phosphate, and the buffer is Tris buffer with a pH of 8.

5.

4. The multi-point wireless monitoring system for ischemic heart according to claim 2, characterized in that: The amount of the amino carbon nanotubes is 30-60 mg, the amount of the buffer is 7 ml, the ultrasonic mixing time is 1-2 h, the amount of dopamine is 8-10 mg, the amount of the acrylic acid solution is 3 ml, the amount of the crosslinker is 6-10 mg, and the amount of the initiator is 20-30 mg.

5. The multi-point wireless monitoring system for ischemic heart according to claim 2, characterized in that: The appropriate condition is irradiation with ultraviolet light.

6. The multi-point wireless monitoring system for ischemic heart according to claim 1, characterized in that: The sensor layer is prepared according to the following method: S1. Making flexible electrodes using an FPC flexible circuit board: the FPC flexible circuit board includes a bottom PI film, a top PI film, and an electrode arranged between the bottom PI film and the top PI film, the electrode including a source electrode, a drain electrode, and a gate electrode, and the top PI film is removed from the electrode portion corresponding to each monitoring site; S2. Making a sensor layer using the flexible electrode: making source, drain and gate lines on the same plane, then forming a graphene channel between the source and drain by wet transfer of graphene, and finally forming an air layer between the gate and the drain and source at each monitoring site by folding it in half to obtain the sensor layer.

7. The multi-point wireless monitoring system for ischemic heart according to claim 1, characterized in that: There are multiple monitoring sites.

8. The multi-point wireless monitoring system for ischemic heart according to claim 1, characterized in that: The Bluetooth signal transmission module uses the nrf52832 chip, and the display terminal is a mobile phone APP.

9. The multi-point wireless monitoring system for ischemic heart according to claim 1, characterized in that: The wireless power receiving module includes a receiving coil implanted in the body, which is used to couple and receive electromagnetic waves sent by a transmitting coil of a wireless power transmitting device outside the human body and convert them into a 5V voltage output. The power management module converts the received 5V voltage into a 3.3V voltage to power the wireless monitoring system.

Images