Device for measuring contact impedance between multi-channel electromyography electrode and biological organism

Abstract

The present application provides a device for measuring the contact impedance between a multi-channel electromyography electrode and a biological organism, comprising: a control processor circuit, a power supply circuit, a measurement circuit, a first multi-channel switch, a second multi-channel switch, a third multi-channel switch, a fourth multi-channel switch, an electrode interface and a grounding interface, wherein the control processor circuit is connected to other circuits and switches; the electrode interface is provided with a multi-channel connector, and the multi-channel connector is separately connected to the first multi-channel switch, the third multi-channel switch and the fourth multi-channel switch; the measurement circuit is further separately connected to the second multi-channel switch and the grounding interface; the second multi-channel switch is further connected to the first multi-channel switch; the first multi-channel switch is further separately connected to the third multi-channel switch, the fourth multi-channel switch and the electrode interface; and the third multi-channel switch and the fourth multi-channel switch are connected to the electrode interface, respectively.

Description

Device for measuring contact impedance between myoelectric multi-channel electrode and biological body

[0001] Priority application

[0002] The present application claims priority to Chinese application No. 202410649960.4, filed on May 24, 2024, entitled "Device for measuring contact impedance between myoelectric multi-channel electrode and biological body". TECHNICAL FIELD

[0003] The present application relates to the technical field of contact impedance measurement devices, and in particular to a device for measuring contact impedance between a myoelectric multi-channel electrode and a biological body. BACKGROUND

[0004] Biological electricity is an electrical phenomenon exhibited by living organisms, such as the biological electricity of the human body, which is derived from the functions of cells. Under certain conditions, biological electricity is regular, and certain physiological processes correspond to an electrical response. According to the change process and regularity of biological electricity, it can be inferred whether the physiological process is in a normal state, thereby determining the health status of the human body.

[0005] Biological electricity technology is widely used in the field of medical monitoring, such as electrocardiogram, electroencephalogram, electromyogram, etc. Biological electrical signals are transmitted through human tissues to the body surface, and when measuring biological electricity, a conductive electrode needs to be fixed on the surface of the human body (such as the skin). In the entire transmission path of the biological electrical signal, the human tissue is considered as a good conductor, and its impedance changes accordingly according to the frequency. The contact impedance between the electrode and the skin changes from several million ohms to several tens of ohms, so the contact impedance between the electrode and the skin directly affects the quality of the biological electrical signal. At the same time, it is generally recognized that the size of the contact impedance between the electrode and the skin directly reflects the contact quality between the electrode and the skin.

[0006] Before and after using a biological electrical signal acquisition device, a resistance measuring device needs to be used to measure the contact impedance between the electrode and the skin once, which is beneficial for us to master the contact condition between the electrode and the skin during the test.

[0007] In the aspects of electrocardiogram, electroencephalogram, electromyogram, and EIT imaging, the measurement of contact impedance between the electrode and the skin is mostly two-electrode method. The general process of the two-electrode method is as follows:

[0008] The two electrodes include an excitation electrode and a measurement electrode. The excitation current is denoted as I, and the measured voltage difference is denoted as V. Then, based on the boundary voltage difference being equal to the product of the contact impedance value and the current I, the contact impedance modulus Z is calculated. The two-electrode method takes the measured contact impedance modulus Z as the resistance value between the two electrodes, which is also the contact impedance.

[0009] The method generally determines the size of the contact impedance through one measurement. Due to the existence of a certain working range of the measurement circuit, a single measurement can only cover a part of the impedance range to be measured, and the measurement value obtained often does not agree with the actual contact impedance, the measurement precision is low, and thus the failure of the electromyographic signal collection occurs. In addition, the traditional two-electrode method is only applicable to the measurement of the contact impedance between a single electromyographic channel electrode and the skin when a pair of differential electrodes is attached to the surface of the human skin, and cannot be applicable to the high-density electromyographic collection demand, i.e., the case of quickly measuring the contact impedance of each channel in the case of a large number of electrode channels (such as 64, 128 channels). SUMMARY

[0010] The present application provides a device for measuring the contact impedance between a multi-channel electromyographic electrode and a biological organism to solve the problems in the background art. The device comprises: a control processor circuit (01), a power supply circuit (11), a measurement circuit (21), a first multi-way switch (31), a second multi-way switch (32), a third multi-way switch (35), a fourth multi-way switch (36), an electrode interface (41), and a ground interface (42).

[0011] The control processor circuit (01) is connected with other circuits and switches;

[0012] The electrode interface (41) is provided with a multi-way connector (411), and the multi-way connector (411) is connected with the first multi-way switch (31), the third multi-way switch (35), and the fourth multi-way switch (36) respectively.

[0013] The measurement circuit (21) is further connected with the second multi-way switch (32) and the ground interface (42) respectively.

[0014] The second multi-way switch (32) is further connected with the first multi-way switch (31).

[0015] The first multi-way switch (31) is further connected with the third multi-way switch (35), the fourth multi-way switch (36), and the electrode interface (41) respectively.

[0016] The third multi-way switch (35) and the fourth multi-way switch (36) are connected with the electrode interface (41) respectively. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0018] Fig. 1 is a circuit logic diagram of a measuring device according to an embodiment of the present application;

[0019] Fig. 2 is a circuit logic diagram of the measuring device when performing a first measurement according to an embodiment of the present application;

[0020] Fig. 3 is a structure diagram of a control processor according to an embodiment of the present application;

[0021] Fig. 4 is a structure diagram of an electrode interface according to an embodiment of the present application;

[0022] Fig. 5 is a structure diagram of a grounding interface according to an embodiment of the present application;

[0023] Fig. 6 is a structure diagram of a first multi-way switch according to an embodiment of the present application;

[0024] Fig. 7 is a structure diagram of a second multi-way switch according to an embodiment of the present application;

[0025] Fig. 8 is a structure diagram of a third multi-way switch according to an embodiment of the present application;

[0026] Fig. 9 is a structure diagram of a fourth multi-way switch according to an embodiment of the present application;

[0027] Fig. 10 is a structure diagram of a measuring circuit according to an embodiment of the present application;

[0028] Fig. 11 is a structure diagram of a power supply circuit according to an embodiment of the present application;

[0029] Fig. 12 is a structure diagram of a display circuit according to an embodiment of the present application;

[0030] Fig. 13 is a structure diagram of a compensation circuit according to an embodiment of the present application;

[0031] Fig. 14 is a structure diagram of a calibration circuit according to an embodiment of the present application;

[0032] Fig. 15 is a structure diagram of an alarm circuit according to an embodiment of the present application;

[0033] Fig. 16 is a structure diagram of a wireless output circuit according to an embodiment of the present application;

[0034] Fig. 17 is a structure diagram of a storage circuit according to an embodiment of the present application;

[0035] Fig. 18 is a structure diagram of a first button, a second button and a third button according to an embodiment of the present application;

[0036] Fig. 19 is a working circuit schematic diagram of a compensation circuit according to an embodiment of the present application;

[0037] Fig. 20 is a working circuit schematic diagram of a calibration circuit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application. In addition, it should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0039] Fig. 1 is a measuring device for measuring the contact impedance between a multi-channel electrode of a high-density electromyographic signal acquisition device and a biological organism, according to an embodiment of the present application. As shown in Fig. 1, and in combination with Fig. 2, the device comprises a control processor circuit (01), a power supply circuit (11), a measuring circuit (21), a first multi-way switch (31), a second multi-way switch (32), a third multi-way switch (35), a fourth multi-way switch (36), an electrode interface (41), and a ground interface (42).

[0040] The control processor circuit (01) is connected with other circuits and switches;

[0041] The electrode interface (41) is provided with a multi-way connector (411), which is connected with the first multi-way switch (31), the third multi-way switch (35), and the fourth multi-way switch (36) respectively;

[0042] The measuring circuit (21) is further connected with the second multi-way switch (32) and the ground interface (42) respectively;

[0043] The second multi-way switch (32) is further connected with the first multi-way switch (31);

[0044] The first multi-way switch (31) is further connected with the third multi-way switch (35), the fourth multi-way switch (36), and the electrode interface (41) respectively;

[0045] The third multi-way switch (35) and the fourth multi-way switch (36) are connected with the electrode interface (41) respectively.

[0046] In the present application, the connection is generally a cable connection without special description, and can be replaced by other connection modes according to actual conditions.

[0047] The high-density myoelectric signal acquisition device multi-channel electrode is an electrode on the high-density myoelectric signal acquisition device, generally includes a signal acquisition electrode (hereinafter referred to as a "signal electrode") and a grounding electrode, wherein the signal acquisition electrode is a flexible electrode attached to the skin surface above the muscle and includes a plurality of channel contact points, and the grounding electrode is a single-channel reference electrode attached to a position away from the muscle to be measured and is not affected by the myoelectric signal. The myoelectric signal acquisition device acquires the myoelectric signal potential difference between the signal electrode and the grounding electrode through the above-mentioned electrodes, so as to diagnose the health and physiological condition of the living body through the myoelectric signal.

[0048] The control processor circuit (01) is connected with the power supply circuit (11), the measurement circuit (21), the display circuit (23), the first multi-way switch (31), the second multi-way switch (32), the third multi-way switch (35), the fourth multi-way switch (36), the electrode interface (41), and the grounding interface (42).

[0049] Optionally, referring to FIG. 3, the control processor circuit (01) includes a microprocessor (011) and a 25Mhz crystal oscillator (012); the microprocessor (011) has control software inside and can be connected with each circuit in the device in a predetermined manner to interact with data and control the working state of the circuit; the 25Mhz crystal oscillator (012) provides a stable and accurate clock signal for the microprocessor (011).

[0050] Further, the microprocessor (011) can be a micro control unit.

[0051] The living body can be a human or other living body.

[0052] The multi-way connector (411) is used for connecting the multi-channel signal electrode of the high-density myoelectric signal acquisition device and receiving the excitation signal for measuring the impedance of the living body from the first multi-way switch (31), the third multi-way switch (35), and the fourth multi-way switch (36).

[0053] Each multi-way connector (411) includes a plurality of channel connection pins, each of which can be connected with one of the connection ends of the first multi-way switch (31), the third multi-way switch (35), or the fourth multi-way switch (36), so as to realize multi-way measurement. When one multi-way connector (411) cannot meet the measurement requirement, a plurality of multi-way connectors (411) can be connected in parallel, or the connection ends can be directly added to the current multi-way connector (411) until the measurement requirement is met.

[0054] Optionally, referring to FIG. 4, a first diode (412) is configured on each channel of the multi-connector (411). FIG. 4 is an example of a multi-connector (411) configured with a first diode (412), which is only an example. The cathode of each first diode (412) is connected to a corresponding pin of the multi-connector (411), and the anode is connected to the negative terminal V12 of the power supply circuit (11).

[0055] The first diode (412) serves as static and surge protection to prevent damage to the internal circuit caused by static and surge voltage received by the multi-connector (411).

[0056] Optionally, referring to FIG. 5, the ground interface (42) includes a ground socket (421) and a second diode (422). The ground socket (421) is connected to the ground electrode. The ground socket (421) is used to receive the excitation return signal returned by the ground electrode. The cathode of the second diode (422) is connected to the ground socket (421), and the anode of the second diode (422) is connected to the negative terminal V12 of the power supply circuit (11).

[0057] The ground electrode is the ground electrode of the myoelectric signal acquisition device. In use, the skin of the living body is connected between the signal electrode and the ground electrode.

[0058] The second diode (422) serves as static and surge protection to prevent damage to the internal circuit caused by static and surge voltage received by the ground socket (421).

[0059] The multi-connector (411) cooperates with the first multi-way switch (31), the second multi-way switch (32), the third multi-way switch (35), and the fourth multi-way switch (36) to realize multi-channel signal transmission. The following is an example.

[0060] For example, referring to FIGS. 1, 2, and 7, the second multi-way switch (32) includes a single-pole three-throw switch multiplexer (321). The control processor circuit (01) is connected to the control pin of the single-pole three-throw switch multiplexer (321). The single-pole three-throw switch multiplexer (321) will switch the internal switch according to the signal 0132 sent by the control processor circuit (01) to forward the received first excitation signal T11 to the input pin of the first multi-way switch (31), the compensation circuit (22), or the calibration circuit (27).

[0061] Referring to FIG. 1, FIG. 2 and FIG. 6, the first multiplexer (31) is a single-pole three-throw switch multiplexer (311); the control processor circuit (01) sends a control signal 0131 to the single-pole three-throw switch multiplexer (311), and the single-pole three-throw switch multiplexer (311) switches the internal switch according to the received control signal 0131, and sends the received first excitation signal T11 to the input end of the third multiplexer (35), the input end of the fourth multiplexer (36) or one pin of the electrode interface (41);

[0062] Referring to FIG. 1, FIG. 2 and FIG. 8, the third multiplexer (35) includes a single-pole thirty-two-throw switch multiplexer (351); the single-pole thirty-two-throw switch multiplexer (351) receives the control signal 0135 sent by the control processor circuit (01), and the single-pole thirty-two-throw switch multiplexer (351) switches the internal switch according to the received control signal 0135, and forwards the first excitation signal T11 to the corresponding path of the electrode interface (41);

[0063] Referring to FIG. 1, FIG. 2 and FIG. 9, the fourth multiplexer (36) includes a single-pole thirty-two-throw switch multiplexer (361); the single-pole thirty-two-throw switch multiplexer (361) receives the control signal 0136 sent by the control processor circuit (01), and the single-pole thirty-two-throw switch multiplexer (361) switches the internal switch according to the received control signal 0136, and forwards the first excitation signal T11 to the corresponding path of the electrode interface (41).

[0064] From the above, it can be seen that the third multiplexer (35) includes 32 paths, which can be numbered 1-32, the fourth multiplexer (36) includes 32 paths, which can be numbered 33-64, and the first multiplexer (31) can also directly send the first excitation signal T11 to the right leg drive electrode pin of the electrode interface 41. Therefore, there are a total of 65 paths, and the electrode interface 41 also has 65 paths (including the right leg drive electrode pin) to connect the 65 channels on the signal electrode. In use, according to the instructions sent by the control processor circuit (01), each path is switched in turn, so that the contact impedance corresponding to each channel can be obtained.

[0065] In addition, it should be noted that this is only an example, and when the multiplexer cannot meet the measurement requirements, the number of first multiplexers (31), third multiplexers (35) and fourth multiplexers (36) can be increased to increase the number of paths and channels, thereby meeting the measurement requirements.

[0066] Optionally, referring to FIG. 2 and FIG. 10, the measurement circuit (21) comprises an impedance measurement chip (211) configured with an impedance measurement circuit and a digital signal processor (English full name: Digital Signal Processing; English abbreviation: DSP) connected with each other; the digital signal processor is connected with the control processor circuit (01), the input of the impedance measurement circuit, i.e. the excitation return signal T12 input, is connected with the ground interface (42), and the first excitation signal output T11 of the impedance measurement circuit is connected with the second multi-way switch (32). The impedance measurement chip (211) can use AD5933 or other integrated circuits with integrated excitation signal generation function and excitation return signal analysis function, and the impedance measurement chip (211) can also be replaced by a circuit composed of discrete components with the same function.

[0067] The control processor circuit (01) performs data interaction with the digital signal data processor through a preset communication mode. After the digital signal processor receives the control information 0121 sent by the control processor circuit (01), the digital signal processor sends a signal output instruction to the impedance measurement circuit. When the impedance measurement circuit receives the output instruction, the output pin outputs a first excitation signal T11 in the form of a sine wave. The first excitation signal T11 passes through the specified electrode path through the cooperation of the first multi-way switch (31), the third multi-way switch (35), the fourth multi-way switch (36) and the electrode interface (41) to pass through the measured object, and then the first excitation signal T11 will be attenuated in amplitude and changed in phase to generate a first excitation return signal T12. The first excitation return signal T12 is returned to the input pin of the impedance measurement chip through the ground interface (42) and transmitted to the DSP through the input pin. The DSP performs discrete Fourier transform (DFT) on the first excitation return signal T12 and sends the transformed data to the control processor circuit (01) to scan each frequency point. The internal software of the control processor circuit (01) calculates the measured impedance value.

[0068] Among them, the measured object is a signal electrode, a biological organism and a ground electrode connected in series.

[0069] Optionally, referring to FIG. 11, the power supply circuit (11) comprises a lithium ion battery (111), a battery management chip (112), and a power converter (113); wherein the lithium ion battery (111) is responsible for powering the entire measuring device, can be repeatedly charged and discharged, has a temperature measuring circuit inside, and will send a temperature signal 1111 inside the lithium ion battery (111) to the control processor circuit (01) to prevent power supply abnormalities caused by high battery temperature; the battery management chip (112) is responsible for detecting the power usage status of the entire measuring device and sending power data 1121 to the control processor circuit (01) for processing; the power converter (113) is a low dropout linear regulator, receives the current output by the lithium ion battery (111), stabilizes the current, outputs a direct current power supply, and then powers the entire circuit through the power supply; the positive electrode V11 of the lithium ion battery (111) is connected to the positive electrode of the power converter (113) and the battery management chip (112), and the negative electrode V12 of the lithium ion battery (111) is first connected to the negative electrode of the power converter (11) and the negative electrode of the measuring device, and then connected to the battery management chip (112).

[0070] Optionally, referring to FIGS. 1, 2, and 12, the measuring device further comprises a display circuit (23) comprising a display (231); the display (231) interacts with the control processor circuit (01) through a pre-set communication mode, and can display the measurement process, channel code, impedance value corresponding to the channel, measurement result, power information, memory card information, and wireless connection status.

[0071] Optionally, referring to FIG. 13, the measuring device further comprises a compensation circuit (22), the compensation circuit (22) comprising an amplifier (221), a first single-pole single-throw switch (222), a first resistor (223), a second resistor (224), a third resistor (225), and a fourth resistor (226); a control pin of the first single-pole single-throw switch (222) is connected to the control processor circuit (01), and a control signal 0133 sent by the control processor circuit (01) can control the opening and closing of the first single-pole single-throw switch (222); one end of the first resistor (223) is connected to a positive electrode V11 of a power supply circuit (11), and the other end of the first resistor (223) is connected to a positive input terminal +IN of the amplifier (221); one end of the second resistor (224) is connected to the positive input terminal +IN of the amplifier (221), and the other end of the second resistor (224) is connected to a negative electrode V12 of the power supply circuit (11); one end of the third resistor (225) is used to receive a first excitation signal T11, and the other end of the third resistor (225) is connected to a negative input terminal -VIN of the amplifier (221); one end of the fourth resistor (226) is connected to the negative input terminal -VIN of the amplifier (221), and the other end of the fourth resistor (226) is connected to an output terminal Vout of the amplifier (221).

[0072] Through the connection, the output terminal of the amplifier (221) sends a compensated excitation signal, denoted as a second excitation signal T21, to an input terminal of the two-way switch multiplexer (222); the control processor circuit (01) sends a control signal 0133 to the first single-pole single-throw switch (222), and the first single-pole single-throw switch (222) switches an internal switch to connect or block the connection between the compensated second excitation signal T21 and the input terminal of the first multi-way switch (31).

[0073] Among them, the amplifier (221) is a precision amplifier. The first resistor (223), the second resistor (224), the third resistor (225), and the fourth resistor (226) are high-precision (error less than 0.1%) resistors.

[0074] Since the original measuring circuit (21) has a limited measurement range, when the impedance of the object to be measured is less than a preset value, for example, less than 7 kilohms, the original measuring circuit (21) cannot measure the accurate impedance due to the limited current driving capability and large equivalent output impedance of the first excitation signal T11 output by the original measuring circuit (21). Therefore, after measuring using the original measuring circuit (21), the impedance less than the preset value is compensated by the above-mentioned compensation circuit (22) to the output first excitation signal T11 of the measuring circuit (21) to reduce the output impedance, enhance the driving capability of the excitation signal, and expand the measurement range, and then the measurement is performed to obtain the accurate small impedance value. The connection of the compensation circuit (21) is realized by configuring the second multi-way switch (32).

[0075] Optionally, referring to Fig. 14, the measuring device further comprises a calibration circuit (27), which comprises a standard resistor (271) and a second single-pole single-throw switch (272); one end of the standard resistor (271) is connected with the first excitation signal T11, the other end of the standard resistor (271) is connected with one end of the second single-pole single-throw switch (272), the other end of the second single-pole single-throw switch (272) is connected with the excitation return signal input end of the measuring circuit (21), and the second single-pole single-throw switch (272) is further connected in communication with the control processor circuit (01).

[0076] The standard resistor (271) is used to provide a reference resistance value R for the measuring circuit (21); the second single-pole single-throw switch (272) can receive the control signal 0127 sent by the control processor circuit (01), and the second single-pole single-throw switch (272) can switch the internal switch according to the control signal 0127 to connect and disconnect the standard resistor (271) and the input end of the measuring circuit (21). The known impedance value R in the calibration circuit and the degree of the measuring circuit (21) in the case of connecting the standard resistor (271) are used to calibrate the internal coefficient of the measuring circuit, so that the measurement error is effectively controlled.

[0077] The standard resistor (271) is a resistor with a known resistance value, and the resistance value can be determined according to the actual situation, and a high-precision standard resistor (with an error less than 0.1%) is selected.

[0078] Optionally, referring to Fig. 15, the measuring device further comprises an alarm circuit (24), which comprises a buzzer (241), a third diode (242) and an N-channel MOSFET (243); the gate of the N-channel MOSFET (243) is connected with the control processor circuit (01) to receive the control level signal sent by the control processor circuit (01), the drain of the N-channel MOSFET (243) is connected with the negative electrode of the buzzer (241), and the source of the N-channel MOSFET (243) is connected with the negative electrode V12 of the power supply circuit (11); one of the feet of the buzzer (241) is connected with the positive electrode V11 of the power supply circuit (11), and the other foot is connected with the drain of the N-channel MOSFET (243), and the buzzer (241) can emit a prompt sound according to the control signal 0124; the anode of the third diode (242) is connected with the positive electrode of the buzzer (241), and the cathode of the third diode (242) is connected with the negative electrode of the buzzer (241), which is used to eliminate the spike signal generated when the alarm circuit (24) works, so as to ensure the normal work of the alarm circuit (24).

[0079] Optionally, referring to FIG. 16, the measuring device further comprises a wireless transmission circuit (25), which comprises a wireless module (251), and the wireless module (251) is respectively in communication connection with the control processor circuit (01) and a terminal device client.

[0080] The wireless module (251) is a multi-protocol module, which can communicate with the control processor circuit (01) through a preset communication interface. The control processor circuit (01) will send data information 0125 to the terminal device in real time through the wireless module (251). The terminal device can be a mobile phone or an upper computer. Further, a client application program corresponding to the measuring device is installed on the terminal device. Through the client application program, the user can view the data sent by the control processor circuit 01, and also can send data information to the control processor circuit (01) through the wireless module (251) using the terminal device.

[0081] Optionally, referring to FIG. 17, the measuring device further comprises a storage circuit (26), which comprises a self-ejecting MicroSD card slot (261) and a memory (262), and the self-ejecting MicroSD card slot (261) is respectively in communication connection with the memory (262) and the control processor circuit 01.

[0082] The self-ejecting MicroSD card slot (261) can adapt to a MicroSD (TF card) memory (262). The control processor circuit (01) is connected with the self-ejecting MicroSD card slot (261) through a preset communication mode, and will store the measured impedance data and device state to the MicroSD (TF card) memory (262) through the self-ejecting MicroSD card slot (261), so as to realize the function of local data storage. The control processor circuit (01) can also be connected with the self-ejecting MicroSD card slot (261) through a preset communication mode, and read the data in the MicroSD (TF card) memory (262).

[0083] Optionally, referring to FIG. 18, the device further comprises a first button (43), a second button (44), and a third button (45); the first button (43) comprises a first tactile switch (431) and a fourth diode (432), the second button (44) comprises a second tactile switch (441) and a fifth diode (442), and the third button (45) comprises a third tactile switch (451) and a sixth diode (452); the first tactile switch (431), the second tactile switch (441), and the third tactile switch (451) are connected to the control processor circuit (01) and output control signals to the control processor circuit (01) after being pressed, and the control processor circuit (01) sends corresponding signals to control the relevant circuit according to the functions defined by the internal software; the cathode of the fourth diode (432) is connected to the pin of the first tactile switch (431), and the anode is connected to the negative electrode V12 of the power supply circuit (11); the cathode of the fifth diode (442) is connected to the pin of the second tactile switch (441), and the anode is connected to the negative electrode V12 of the power supply circuit (11); the cathode of the sixth diode (452) is connected to the pin of the third tactile switch (451), and the anode is connected to the negative electrode V12 of the power supply circuit (11).

[0084] Among them, the fourth diode (432), the fifth diode (442), and the sixth diode (452) play a role in static and surge protection, preventing static and surge voltage from damaging the internal circuit when using the first tactile switch (431), the second tactile switch (441), and the third tactile switch (451).

[0085] When it is necessary to measure whether the connection between the electrode of the electromyographic signal acquisition device and the muscle meets the requirements, a preliminary impedance value measurement can be performed first, referring to FIG. 2, the preliminary impedance value measurement process is as follows:

[0086] Pressing the second button (44) for 5 seconds, the control processor circuit (01) performs self-checking on the measurement circuit, and after the self-checking is passed, "measuring" is displayed on the display circuit (23), and the second button (44) is pressed again, and the device starts to measure the impedance value of the object to be measured.

[0087] After the control processor circuit (01) receives the start test instruction 4401 from the second button (44), the control processor circuit (01) sends an instruction signal (0121) to the measurement circuit (21) to trigger the measurement, the measurement circuit (21) sends a sine wave, that is, the first excitation signal T11 to the input end of the second multiplexer (32), the control processor circuit (01) sends the second multiplexer (32) switching instruction 0132, the first excitation signal T11 passes through the second multiplexer (32) to the input end of the first multiplexer (31), the control processor circuit (01) sends the first multiplexer (31) switching instruction 0131, the first excitation signal T11 passes through the first multiplexer (31) to the input end of the third multiplexer (35) or to the input end of the fourth multiplexer (36) or directly to the right leg drive electrode pin of the electrode interface (41). The first multiplexer (31), the third multiplexer (35) and the fourth multiplexer (36) will switch in the order preset by the switching instruction, and the first excitation signal T11 will be connected to the electrode points in each channel No. 1-65 of the electrode interface (41) in turn, so as to realize multi-channel measurement and improve the accuracy of measurement. When the electrode is in close contact with the skin, the contact impedance of the electrode-skin contact interface is small at this time, and the impedance of the normal human skin tissue is small under the high frequency of the first excitation signal T11, so the overall impedance of the measured object is small. The first excitation signal T11 will attenuate when passing through the skin tissue, thereby generating a first excitation return signal T12. The first excitation return signal T12 is connected to the ground interface (42) through the ground electrode (for example, the ground electrode can be a bracelet electrode worn on the skin or a conventional Ag / AgCl gel electrode), and then the first excitation return signal T12 is sent to the input pin of the measurement circuit (21) through the ground interface (42). After the measurement circuit (21) receives the first excitation return signal T12, the DSP inside the measurement circuit (21) will perform discrete Fourier processing on the first excitation return signal T12. The measurement circuit (21) sends the measurement result data to the control processor circuit (01) for processing to complete the preliminary impedance value measurement.

[0088] The above measurement process, the compensation circuit (22) and the calibration circuit (27) are disconnected by the second multiplexer (32) and do not participate in this measurement. The output end of the compensation circuit (22) is disconnected by the first single-pole single-throw switch (222) inside it.

[0089] When the preliminary measurement is completed and some channels have impedance less than the preset value, the first excitation signal T11 output by the measurement circuit (21) is compensated by the above-mentioned compensation circuit (22) to expand the measurement range, and then the measurement is performed again to obtain the accurate value of the contact impedance under the small resistance condition. Alternatively, referring to FIG. 19, the small impedance measurement process is as follows:

[0090] When the control processor circuit (01) completes the preliminary resistance value collection, it will calculate and process according to the measured impedance value data. When the measured impedance value is insufficient in precision (for example, the preliminary measured impedance is less than the preset value of 5K ohms or 7K ohms, etc.), the control processor circuit (01) will send a channel switching signal (0132) to make the second multi-way switch (32) switch the sinusoidal first excitation signal T11 to the compensation circuit (22). The first excitation signal T11 is amplified in driving capability by the compensation circuit (22) and sends the compensated second excitation signal T21 to the input end of the first single-pole single-throw switch (222). The control processor circuit (01) will send a channel switching signal 0133 to make the first single-pole single-throw switch (222) in the compensation circuit (22) conductive. The compensated second excitation signal T21 will pass through the first single-pole single-throw switch (222) and be sent to the input end of the first multi-way switch (31). The control processor circuit (01) will send a first multi-way switch (31) switching instruction 0131. The second excitation signal T21 is connected to the input end of the third multi-way switch (35), or the input end of the fourth multi-way switch (36), or the right leg driving electrode pin of the electrode interface (41) through the first multi-way switch (31). The signal return process of the returned second excitation return signal T22 is the same as that of the above-mentioned first excitation return signal T12, which will not be described here.

[0091] When measuring small impedance, the calibration circuit (27) will receive the switching control signal (0127) sent by the control processor circuit (01) to make the second single-pole single-throw switch (272) in the calibration circuit (27) internal disconnected, so the calibration circuit (27) will not participate in the work.

[0092] The second multi-way switch (32) is a single-pole three-throw switch multiplexer (321) inside. When the second multi-way switch (32) outputs to the compensation circuit (22), the other outputs are disconnected from the input end, so the signal path from the second multi-way switch (32) to the first multi-way switch (31) is disconnected.

[0093] When the control processor circuit (01) completes the small impedance value measurement, it will calculate and process again according to the measured impedance value data and save all the data.

[0094] Combining the preliminary measurement and small impedance measurement results, the final measurement results will be displayed through the display circuit (23). The resistance values of each channel are displayed row by row, and the display page can be switched by pressing the third button (45) and the first button (43).

[0095] When the measured value is insufficient in precision, it can be calibrated by the calibration circuit 27. Optionally, referring to FIG. 20, the calibration process is as follows:

[0096] When the measurement accuracy is insufficient, the internal calibration instruction can be triggered by long pressing the button (45). The control processor circuit (01) sends a channel switching signal (0132) to make the second multi-way switch (32) switch the first excitation signal T11 to the calibration circuit (27). The control processor circuit (01) sends a channel switching signal (0127) to make the input and output terminals of the second single-pole single-throw switch (272) in the calibration circuit (27) conductive. The standard resistor (271) in the calibration circuit (27) is connected to the input terminal of the measurement circuit (21), triggering the measurement of the standard resistor (271) and taking the measurement value as the standard corresponding impedance value. The control processor circuit (01) recalculates the calibration coefficient in the measurement software according to the standard impedance corresponding measurement value and records it for future measurement.

[0097] Exemplarily, the measurement process is described taking the signal electrode, the human body, and the ground electrode as examples.

[0098] Install the signal electrode and the ground electrode:

[0099] One end of the signal electrode is fixedly connected to the skin, ensuring that each metal point of the signal electrode is in close contact with the skin. The other end of the signal electrode is inserted into the electrode interface (41) of the measurement device.

[0100] Insert the plug of the ground electrode into the ground interface (42) of the measurement device. The other end of the ground electrode is in contact with the skin using a ground bracelet or a gel electrode.

[0101] Power-on test:

[0102] Press the second button (44) and hold for 5 seconds, then release your hand. At this time, the measurement device is powered on and performs self-checking. After about 3 seconds, you can see the "device normal" prompt on the display 231, indicating that the measurement device can be used for impedance measurement. If a continuous "ding ding ding" short three sound is emitted, indicating that the detection is abnormal, the measurement device cannot be used.

[0103] Immediately release the second button (44) after pressing it. The device starts testing. After about 3 seconds, you can hear a continuous "ding" sound for 1 second, indicating that the test is complete.

[0104] Data display:

[0105] After the test is completed, the channel number and the contact impedance value can be displayed on the display. It should be noted that the displayed contact impedance value is the accurate value combined with the preliminary impedance measurement and the small impedance measurement results.

[0106] When the number of electrodes is too large, press the first button (43) immediately and release it to page down.

[0107] Pressing the third button (45) immediately releases, page up, to view the test results in the measuring device end;

[0108] Pressing the third button (45) for a long time can trigger the internal calibration function, and after calibration, the second button (44) needs to be pressed again to trigger the measurement.

[0109] Data transfer:

[0110] Method one: connect to the terminal device through the wireless function, such as mobile phone APP or computer PC client, data backup;

[0111] Method two: pull out the TF memory card in the SD card slot and insert it into the computer or adapter to copy and cut the measurement data.

[0112] The electromyography multi-channel electrode and the contact impedance measurement device between the biological organism provided by the application comprise a control processor circuit, a plurality of multi-way switches, and an electrode interface provided with a multi-way connector; through the plurality of multi-way switches and the electrode interface provided with the multi-way connector, a multi-channel measurement device is set, and the current loop of the specified channel electrode point of the high-density electrode can be turned on to the excitation output of the measurement circuit (21) under the cooperation of the plurality of multi-way switches and the electrode interface provided with the multi-way connector according to the instruction sent by the control processor circuit, one contact impedance value is measured by using the channel of each electrode point, and the contact state of the muscle and the electrode is determined through a plurality of contact impedance values, so as to ensure the reliability of the contact of each channel electrode point, and then the success rate of electromyography signal acquisition is also improved. In addition, when the impedance to be measured is small, the second multi-way switch (32) is configured by the control processor circuit to connect the compensation circuit (22) to the measurement loop, so as to increase the output driving capability of the first excitation signal T11 output by the measurement circuit (21), reduce the output impedance, so that the circuit can measure the impedance value in a smaller range, so as to cope with a large range of contact impedance values to be measured of the high-density electromyography electrode. In addition, by connecting the input end of the second multi-way switch (32) to the output end connected with the calibration circuit (27), the first excitation signal T11 can be introduced into the calibration circuit, the standard resistance (271) with a known impedance value in the calibration circuit is used, and the degree of the measurement circuit (21) in the case of connecting the standard resistance (271) is used to calibrate the internal coefficient of the measurement circuit, so that the measurement error is effectively controlled. The above-mentioned multi-channel switching, small impedance compensation measurement and calibration technology can be flexibly combined under software configuration, so as to automatically and quickly measure the contact impedance of the multi-channel electrode with high precision, guide the attachment and installation of the high-density electromyography electrode, and guarantee the signal quality of measurement.

[0113] In addition, it should be noted that the scope of the present application includes the feasible technical solutions formed by the specific combinations of the above technical features, and should also cover the feasible other technical solutions formed by the arbitrary combinations of the above technical features or equivalent features without departing from the above application concept.

[0114] Finally, it should be noted that the content not described in the technical solutions of the present application can be implemented using the prior art. In addition, the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A device for measuring the impedance of the interface between a multi-channel myoelectric electrode and a living organism, characterized in that it comprises: The application relates to a measurement device for measuring the voltage of a battery, comprising: a control processor circuit (01), a power supply circuit (11), a measurement circuit (21), a first multiplexer (31), a second multiplexer (32), a third multiplexer (35), a fourth multiplexer (36), an electrode interface (41), and a ground interface (42); the control processor circuit (01) is connected with other circuits and switches; the electrode interface (41) is provided with a multiplexer connector (411) connected with the output ends of the first multiplexer (31), the third multiplexer (35), and the fourth multiplexer (36) respectively; the output end of the measurement circuit (21) is further connected with the second multiplexer (32), and the input end is further connected with the ground interface (42); the output end of the second multiplexer (32) is further connected with the first multiplexer (31); the output end of the first multiplexer (31) is further connected with the third multiplexer (35), the fourth multiplexer (36), and the electrode interface (41) respectively; the third multiplexer (35) and the fourth multiplexer (36) are connected with the electrode interface (41) respectively; the measurement device further comprises a compensation circuit (22), wherein the compensation circuit (22) comprises an amplifier (221), a first single-pole single-throw switch (222), a first resistor (223), a second resistor (224), a third resistor (225), and a fourth resistor (226); the control foot of the first single-pole single-throw switch (222) is connected with the control processor circuit (01), and the control signal (0133) sent by the control processor circuit (01) can control the opening and closing of the first single-pole single-throw switch (222); one end of the first resistor (223) is connected with the positive electrode V11 of the power supply circuit (11), and the other end of the first resistor (223) is connected with the positive input end +VIN of the amplifier (221); one end of the second resistor (224) is connected with the positive input end +VIN of the amplifier (221), and the other end of the second resistor (224) is connected with the negative electrode V12 of the power supply circuit (11); one end of the third resistor (225) is connected with one output end of the second multiplexer (32) for receiving a first excitation signal T11, and the other end of the third resistor (225) is connected with the reverse input end -VIN of the amplifier (221); one end of the fourth resistor (226) is connected with the reverse input end -VIN of the amplifier (221), and the other end of the fourth resistor (226) is connected with the output foot Vout of the amplifier (221) and the input end of the first multiplexer (31).

2. The measuring device of claim 1, wherein, The measuring device further comprises a calibration circuit (27), which comprises a standard resistor (271) and a second single-pole single-throw switch (272); one end of the standard resistor (271) is connected to one end of the second single-pole single-throw switch (272), the other end of the standard resistor (271) is connected to an output pin of the second multi-way switch (32), the other end of the second single-pole single-throw switch (272) is connected to the measuring circuit (21), and the second single-pole single-throw switch (272) is further connected to the control processor circuit (01) in communication.

3. The measuring device of claim 2, wherein, The measuring device further comprises an alarm circuit (24), which comprises a buzzer (241), a third diode (242) and an N-channel MOSFET (243); the gate of the N-channel MOSFET (243) is connected to the control processor circuit (01) in communication, the drain of the N-channel MOSFET (243) is connected to the negative electrode of the buzzer (241), the source of the N-channel MOSFET (243) is connected to the negative electrode V12 of the power supply circuit (11); the positive electrode of the buzzer (241) is connected to the positive electrode V11 of the power supply circuit (11), and the negative electrode is connected to the drain of the N-channel MOSFET (243); the negative electrode of the third diode (242) is connected to the positive electrode of the buzzer (241), and the positive electrode of the third diode (242) is connected to the negative electrode of the buzzer (241).

4. The measuring device of claim 2, wherein, The ground interface (42) comprises a ground socket (421) and a second diode (422); the ground socket (421) is connected to a ground electrode; the ground socket (421) is used to receive the first excitation return signal T12 returned by the ground electrode; the cathode of the second diode (422) is connected to the ground socket (421), and the anode of the second diode (422) is connected to the negative electrode V12 of the power supply circuit (11).

5. The measuring device of claim 1, wherein, Each channel of the multi-way connector (411) is configured with a first diode (412); the cathode of each first diode (412) is connected to a corresponding pin of the multi-way connector (411), and the anode is connected to the negative electrode V12 of the power supply circuit (11).

6. The measuring device of claim 1, wherein, The measuring circuit (21) comprises an impedance measurement chip (211) configured with an impedance measurement circuit and a digital signal processor connected to each other; the digital signal processor is connected to the control processor circuit (01), and the impedance measurement circuit is connected to the second multi-way switch (32) and the ground interface (42) respectively.

7. The measuring device of claim 2, wherein, The measuring device further comprises a wireless transmission circuit (25), which comprises a wireless module (251) connected to the control processor circuit (01) and a terminal device in communication respectively.

8. The measuring device of claim 2, wherein, The measuring device further comprises a storage circuit (26), which comprises a self-ejecting MicroSD card slot (261) and a memory (262), and the self-ejecting MicroSD card slot (261) is respectively in communication connection with the memory (262) and the control processor circuit (01).

9. The measuring device according to any one of claims 1 to 8, characterized in that The device further comprises a first button (43), a second button (44) and a third button (45); the first button (43) comprises a first tactile switch (431) and a fourth diode (432), the second button (44) comprises a second tactile switch (441) and a fifth diode (442), and the third button (45) comprises a third tactile switch (451) and a sixth diode (452); the first tactile switch (431), the second tactile switch (441) and the third tactile switch (451) are connected with the control processor circuit (01); the cathode of the fourth diode (432) is connected with the pin of the first tactile switch (431), and the anode is connected to the negative electrode V12 of the power supply circuit (11); the cathode of the fifth diode (442) is connected with the pin of the second tactile switch (441), and the anode is connected to the negative electrode V12 of the power supply circuit (11); the cathode of the sixth diode (452) is connected with the pin of the third tactile switch (451), and the anode is connected to the negative electrode V12 of the power supply circuit (11).

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