Deep muscle electrical stimulation experiment system capable of measuring electric field distribution

Abstract

The invention provides a deep muscle electrical stimulation experiment system capable of measuring electric field distribution. The deep muscle electrical stimulation experiment system comprises a microcontroller, an electric signal transmission module, a voltage signal acquisition module, a tension signal acquisition module and a supporting module, the microcontroller is used for generating an electrical stimulation signal and receiving, processing and analyzing three-dimensional electric field distribution and muscle tension data of the phase interference electric field; the electrical signal transmission module is used for outputting electrical stimulation signals, superposing the electrical stimulation signals to form coherent wave signals with different vector directions, and collecting voltage and muscle tension signals; the voltage signal acquisition module is used for measuring three-dimensional electric field distribution of a phase interference electric field; the tension signal acquisition module is used for recording deep muscle tension signals; the support module is used for fixing a plurality of metal balls, a plurality of pairs of test electrodes, a force transducer, a muscle specimen, a one-dimensional mobile platform and the like. The three-dimensional electric field distribution of the phase interference electric field can be measured, and the electric stimulation effect of the vector direction change of the electric field on deep muscles can be researched.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical instruments, and particularly relates to an electrical stimulation experimental system for deep muscles capable of measuring electric field distribution, whose function is to measure the three-dimensional electric field distribution of the phase interference electric field and display the change of the phase interference electric field vector direction in space on the electrical stimulation effect of deep muscles. Background Art

[0002] Electrical stimulation technology has long been widely used in clinical treatment of muscle diseases and in the field of sports training to improve muscle function. In the past, direct current and low-frequency alternating current were mostly used for electrical stimulation, but both direct current and low-frequency alternating current are difficult to penetrate deep into human tissues and cannot effectively stimulate deep muscles of the human body. Many widely used electrical stimulation technologies, such as Neuromuscular Electrical Stimulation (NMES), Functional Electrical Stimulation (FES), etc., use low-frequency electricity, and generally output the stimulation current through surface electrodes on the skin. In conventional electrical stimulation experiments, such as in physiology teaching and research, the electrical stimulation signals used are mostly square waves, sine waves or triangular waves, and only one output is required.

[0003] In 2017, Grossman et al. used Temporal Interference Electrical Fields (TI) in the journal *Cell* to achieve non-invasive stimulation of deep brain nerve tissues without causing excitement of nerve tissues in the superficial brain regions of mice, demonstrating that TI is an effective means of selective non-invasive electrical stimulation of deep tissues. This method uses two pairs of electrodes to apply two sinusoidal alternating current signals above kilohertz with a certain frequency difference. Under the interference effect, a low-frequency envelope wave electric field will be generated in the central region where the two currents are superimposed. This electric field changes with time and space, and the electric field distribution is very complex. TI electric field stimulation is a new type of non-invasive deep stimulation means with great research value and application prospect internationally. How to improve the effectiveness of TI technology is a topic of concern in this field. The electromagnetic field is a vector field, with magnitude and direction at each point in space. Due to the limitations of previous calculation and measurement means, the research on the interaction between anisotropic excitable tissues (such as muscle and nerve tissues) and the electromagnetic field has only focused on the electric field strength. Whether the biological response caused by TI electric field stimulation will be affected by the electric field vector direction, that is, the relationship between the TI electric field vector direction and the stimulation effect has not been reported in the literature, and a new type of experimental measurement device is needed.

[0004] Muscles are anisotropic excitable tissues and are one of the most commonly used specimens for electrical stimulation. Muscles are sensitive to electrical signals and can quickly respond after electrical stimulation, making it easy to directly observe muscle contraction. Studying the effects of TI stimulation on isolated muscles will significantly reduce the experimental difficulty and complexity.

[0005] In a preliminary search for comparative documents related to muscle electrical stimulation, it was found that:

[0006] Comparative document 1, with the invention name "Device for in-situ testing of the elasticity of frog muscle bundles" (CN207640425U), discloses: providing a device for in-situ testing and acquisition of the elasticity of frog muscle bundles. The controller is used to send a test signal to the electro-acupuncture stimulation module and receive and process the feedback signal from the force-sensing module. The device outputs a single-channel electrical pulse stimulation signal. The muscle bundle is horizontally fixed, and an electro-acupuncture needle (stimulation electrode) directly contacts the muscle bundle. The drawback of this invention is that it only focuses on the simple process of collecting the contraction force generated by frog muscles during electrical stimulation and does not consider the specific stimulating effects caused by a certain specific electrical signal.

[0007] Comparative document 2 ("A simple and effective auxiliary device for detecting the physiological functions of isolated sciatic nerve and gastrocnemius muscle of toads", Cui Hong, Song Tingting, etc., Chinese Journal of Pathophysiology, Vol. 32, No. 9, pp. 1723-1728) discloses: lifting the sciatic nerve ligation thread and placing the sciatic nerve on the electrode in the nerve trough (a stimulation electrode made of a stainless steel syringe needle). The stimulation parameter is a single stimulus, and a square wave signal is used. Fix the crossbar on the iron stand with a double concave clamp; connect the ligation thread of the knee joint cartilage to the tension transducer; adjust the base of the iron stand to keep the nerve trough in a nearly horizontal state. The attached Figure 1 representation shows that: the fixing bracket includes a bracket, and a force sensor is fixed at the top of the bracket. The force sensor is connected to the muscle through a connecting wire; a muscle placement device is arranged in the middle of the bracket, and simply placing 1 muscle vertically in the organ bath plays a fixing role; the nutrition device is: soaking the specimen fixed on the L-shaped tube in Ringer's solution for 1 h. It can be seen that comparative document 2 detects the physiological functions of the two by directly stimulating the sciatic nerve to cause the contraction of the gastrocnemius muscle.

[0008] The intention of Comparative Document 3 (CN113470496B, with the invention title "A Demonstration System for Muscle Contraction") is to demonstrate the selective stimulation effect of coherent waves on a muscle array. In the embodiment, 5 excised muscles are fixed by petal-shaped fixing rings to form a circular deep structure with 4 muscles arranged around (shallow layer) and 1 muscle in the center (deep layer); the upper ends of the 5 excised muscles are respectively connected to 5 force sensors; the wires pass through the fixing columns of the petal-shaped fixing rings and are connected to 4 electrode plates on the side wall, directly outputting 2 high-frequency sine signals to the 4 shallow muscles within the petal-shaped fixing ring. The result is that 1 muscle in the center (deep layer) contracts due to the stimulation of the coherent wave generated by the superposition of the 2 high-frequency sine signals, and the corresponding 1 force sensor records the change in tension; however, the 4 muscles around (shallow layer) directly receiving the electrical signals (because they are mainly stimulated by alternating current signals above 1 kHz and do not become excited and do not contract) remain stationary, and the change in tension recorded by the corresponding 4 force sensors is significantly smaller than the change in tension recorded by the force sensor corresponding to the muscle in the center (deep layer). Thus, it can be seen that this invention focuses on the effect difference between the muscles around (shallow layer) and the muscle in the center (deep layer) in the muscle array under the stimulation of the same coherent wave. The deficiency of this invention is that the connection method between the stimulation signal output module and the electrode plate is fixed, one wire is connected to the corresponding one electrode plate, and the electrode plate is fixed on the side wall of the petal-shaped fixing ring, unable to adjust the relative position between the electrode plate (stimulation electrode) and the muscle specimen, and unable to superpose to form coherent electric fields with different vector directions.

[0009] In summary, none of the existing inventions have the following functions: (1) measuring the three-dimensional electric field distribution of the phase interference electric field, (2) displaying the electrostimulation effect on deep muscles caused by the change in the vector direction of the phase interference electric field in space, etc. In order to display the stimulation effect of the change in the vector direction of the phase interference electric field on deep muscles, it is first necessary to measure the three-dimensional electric field distribution of the phase interference electric field, and then study the change in the electrostimulation effect on deep muscles caused by the change in the electric field vector direction. There is an urgent need in the field to design an innovative electrostimulation experiment system, which has stable performance, is easy to operate and has obvious effects, integrating stimulation signal output, a stable support structure, voltage signal acquisition and tensile force signal acquisition, especially can conveniently output two independent alternating current signals above kHz, quickly adjust the circuit output mode to superpose and form phase interference electric fields with different vector directions, is easy to change the relative spatial positions of the stimulation electrode, test electrode and muscle specimen, directly evaluate the stimulation effect, and is conducive to the theoretical research work in the aspect of muscle electrostimulation. Summary of the Invention

[0010] The present invention provides an electrostimulation experiment system for deep muscles that can measure the electric field distribution, can adjust the relative spatial positions of the stimulation electrode, test electrode and muscle specimen, quickly adjust the circuit output mode, directly evaluate the stimulation effect, and is conducive to the theoretical research work in the aspect of muscle electrostimulation.

[0011] In the first aspect of the present invention, a deep muscle electrical stimulation experiment system capable of measuring the electric field distribution is provided. The electrical stimulation experiment system includes a microcontroller, an electrical signal transmission module, a voltage signal acquisition module, a tensile force signal acquisition module, and a support module.

[0012] The electrical signal transmission module is used to output electrical stimulation signals and collect voltage and muscle tensile force signals. The electrical signal transmission module includes an input / output (I / O) device, a linear stimulation isolator, a four-pole triple-throw band switch, and a metal ball. The I / O device includes an output D / A module and an input A / D module. The D / A module is used for the mutual conversion between digital signals and analog signals, and the A / D module is used for the mutual conversion between analog signals and digital signals. The output D / A module of the I / O device is respectively connected to the microcontroller and the linear stimulation isolator. The four-pole triple-throw band switch is respectively connected to the linear stimulation isolator and the metal ball. The metal ball is used to output electrical stimulation signals. The voltage signal acquisition module includes three pairs of test electrodes, and the electrodes are used to measure the three-dimensional electric field distribution of the phase interference electric field. The voltage signal acquisition module is connected to the input A / D module, and transmits the collected voltage analog signal to the electrical signal transmission module. The input A / D module converts the voltage analog signal into a digital signal and transmits it to the microcontroller. The tensile force signal acquisition module is used to collect muscle tensile force signals, and transmits the collected tensile force analog signal data to the input A / D module to be converted into a digital signal and transmitted to the microcontroller. The support module includes a lifting device, a plurality of support rods, a variety of fixing rods, and multiple three-dimensional displacement devices. The three-dimensional displacement devices are used to fix the support rods and the fixing rods. The metal ball is fixed at the bottom end of the support rod. The three-dimensional displacement devices can adjust the movement of the metal ball in any direction in space. The lifting device includes a lifting platform and a liftable insulating container. The three-dimensional displacement devices and the lifting device are respectively detachably fixed on the support module.

[0013] The above-mentioned insulating container is filled with a liquid conductive medium. There are two linear stimulation isolators, which respectively output two-way kilohertz sinusoidal alternating current signals through the metal balls to generate a phase interference electric field in the liquid conductive medium of the insulating container, and generate phase interference electric fields with different vector directions through different position states of the four-pole triple-throw band switch. The metal ball is completely immersed in the conductive medium of the insulating container.

[0014] The above-mentioned tensile force signal acquisition module includes a force sensor and a signal transmitter. The head of the force sensor has a vertical annular hook for hanging the muscle and measuring the muscle tensile force data. The signal transmitter is used to amplify the output signal of the force sensor. The signal transmitter is respectively connected to the force sensor and the A / D module of the I / O device.

[0015] The above voltage signal acquisition module further includes a signal amplifier. The test electrodes respectively collect the voltage signals at two points in the X, Y, and Z directions of a certain point of the phase interference electric field at any point in space. The signal amplifier is respectively connected to the test electrodes and the A / D module of the I / O device, and is used to amplify the voltage analog signal and output a voltage digital signal.

[0016] A composite test bracket is fixed on the above three-dimensional displacement platform. The composite test bracket includes a one-dimensional displacement platform and I-shaped and II-shaped fixing rods. One side of the one-dimensional displacement platform is fixedly connected to the three-dimensional displacement platform through the I-shaped fixing rod. The force sensor is fixed at the end of the I-shaped fixing rod. The other side of the one-dimensional displacement platform is fixedly connected to the upper end of the II-shaped fixing rod. A muscle is fixedly hung between the vertical annular hook on the force sensor and the end of the II-shaped fixing rod. By moving the one-dimensional displacement platform up and down, the pre-tension of the muscle can be adjusted.

[0017] The above liquid conductive medium has an electrical conductivity similar to that of the muscle to be measured. In a specific embodiment, the electrical conductivity of the liquid conductive medium is 80-120% of the electrical conductivity of the muscle to be measured.

[0018] There are more than 6 above three-dimensional displacement platforms. Each of the 4 three-dimensional displacement platforms is fixed with a support rod, and the support rod is used to fix a metal ball. On the other 2 three-dimensional displacement platforms, III-shaped and IV-shaped fixing rods are respectively fixed. The bottom surface of the III-shaped fixing rod is fixed with two pairs of electrode needles for measuring the electric field distribution in the X and Y axis directions at any point in the phase interference electric field. The bottom surface of the IV-shaped fixing rod is fixed with a pair of electrode needles for measuring the electric field distribution in the Z axis direction at any point in the phase interference electric field.

[0019] For the above experimental system for electrically stimulating muscles, the support module is a double-layer base. There are more than 6 three-dimensional displacement platforms. Each of the 4 three-dimensional displacement platforms is fixed with a support rod, and the end of each support rod is respectively fixed with a metal ball. On the other 2 three-dimensional displacement platforms, III-shaped and IV-shaped fixing rods are respectively fixed. The bottom surface of the III-shaped fixing rod is fixed with two pairs of electrode needles for measuring the electric field distribution in the X and Y axis directions at any point in the phase interference electric field. The bottom surface of the IV-shaped fixing rod is fixed with a pair of electrode needles for measuring the electric field distribution in the Z axis direction at any point in the phase interference electric field. The three-dimensional displacement platform can be disassembled or installed on the base as needed.

[0020] The above support module is a double-layer base. The double-layer base is divided into an upper plate, a lower plate, and a bottom rod connecting and fixing the upper plate and the lower plate. The distance between the upper plate and the lower plate is adjusted by adjusting the length of the bottom rod. The upper plate is in a shape of a double-square with a hollow in the middle. In a specific embodiment, both the upper plate and the lower plate are optical plates.

[0021] A plurality of threaded fixing holes are distributed on the upper plate and the lower plate, and the three-dimensional displacement platform is fixed at any position on the double-layer base through the threaded fixing holes. The three-dimensional displacement platform is detachably or fixedly installed on the base according to requirements, and the threaded fixing holes are evenly distributed.

[0022] The main body of the above-mentioned support rod is hollow and can be arranged with wires.

[0023] The structure of the present invention mainly consists of five parts, and the main components of each part are as follows.

[0024] (1) Microcontroller. In the embodiment of the present invention, the microcontroller adopts a microcomputer.

[0025] 1. Computer: Write the stimulation signal code in the computer MATLAB software, which can generate any required electrical stimulation signal and demonstrate the stimulation effects of different stimulation signals on muscles; receive the three-dimensional electric field distribution data of the measured phase interference electric field and the tensile force data generated when the muscle is electrically stimulated, and perform various data analysis and processing in the computer.

[0026] (2) Electrical signal transmission module.

[0027] This module includes a USB-6361 multi-functional I / O device, two A395 linear stimulation isolators, a four-pole three-throw band switch and four metal balls, and realizes three main functions. (1) Output electrical stimulation signal: After converting the electrical stimulation digital signal generated by the microcontroller into an analog signal through the D / A of the USB-6361 multi-functional I / O device, it passes through two A395 linear stimulation isolators, a four-pole three-throw band switch and four metal balls, and outputs two kHz alternating current signals with a constant current in three ways, and then superimposes to generate a phase interference electric field with different vector directions. In the embodiment of the present invention, two kHz sinusoidal alternating current signals are output, and in practical applications, various different alternating current signals can be output in the microcontroller according to requirements; (2) Collect voltage signals: When measuring the three-dimensional electric field distribution of the phase interference electric field, through the A / D of the USB-6361 multi-functional I / O device, the voltage analog signals at two points at a small distance on both sides of the measured point in the X or Y or Z direction recorded by the signal amplifier in the voltage signal acquisition module are converted into digital signals and then input into the microcontroller; (3) Collect tensile force signals: When collecting the tensile force change generated after the muscle specimen is stimulated by the phase interference electric field, through the A / D of the USB-6361 multi-functional I / O device, the tensile force analog signal recorded by the signal transmitter in the tensile force signal acquisition module is converted into a digital signal and then input into the microcontroller. The above-mentioned output of electrical stimulation signals, collection of voltage signals and collection of tensile force signals are three independent operation processes, which can be carried out synchronously or separately.

[0028] 2. USB-6361 Multi-Functional I / O Device: The USB-6361 multi-functional I / O device produced by National Instruments Corporation of the United States, with a supporting USB cable, is connected to a computer through a USB interface. The USB-6361 multi-functional I / O device has a total of two pairs of D / A output interfaces and multiple pairs of A / D input interfaces. Each pair of output interfaces can output one analog stimulation signal, and each pair of input interfaces can input one digital electrical signal. During the process of outputting an electrical stimulation signal, the USB-6361 multi-functional I / O device can convert the digital signal generated in the microcontroller into an analog signal, and then transmit the electrical stimulation signal to the A395 linear stimulation isolator through the output interface. During the process of transmitting the voltage signal or the tensile force signal back to the microcontroller, the USB-6361 multi-functional I / O device receives the voltage signal recorded by the signal amplifier in the voltage signal acquisition module, or the USB-6361 multi-functional I / O device receives the tensile force signal recorded by the signal transmitter in the tensile force signal acquisition module, converts the analog signal into a digital signal and then inputs it into the microcontroller.

[0029] 3. The First A395 Linear Stimulation Isolator: The A395 linear stimulation isolator produced by World Precision Instruments Company of the United States has one input interface and two output interfaces, one positive and one negative. The input interface of the first A395 linear stimulation isolator is connected to the first pair of D / A output interfaces of the USB-6361 multi-functional I / O device, and the output interfaces of the first A395 linear stimulation isolator are connected to two of the incoming wire ports of the four-way three-position switch; one A395 linear stimulation isolator outputs a stimulation current with stable intensity, so that the stimulation current is not interfered by the change of the external resistance.

[0030] 4. The Second A395 Linear Stimulation Isolator: The input interface of the second A395 linear stimulation isolator is connected to the second pair of D / A output interfaces of the USB-6361 multi-functional I / O device, and the output interfaces are connected to the other two incoming wire ports of the four-way three-position switch; the rest of the structure of the second A395 linear stimulation isolator is the same as that of the first A395 linear stimulation isolator.

[0031] 5. Four-Way Three-Position Switch: The four-way three-position switch has 4 incoming wire ports, 4 outgoing wire ports and 1 knob. The 4 incoming wire ports are connected to the output ends of 2 A395 linear stimulation isolators, and the 4 outgoing wire ports are connected to the wires of 4 metal balls. By connecting different circuits inside the four-way three-position switch and rotating the knob to connect a certain circuit, the output form of the two electrical signals can be conveniently changed, and the direction of the phase interference electric field vector formed in space changes. The wiring method of the four-way three-position switch is shown in Attachment Figure 3 A-3C.

[0032] 6. First metal sphere (E1): A conductive sphere made of metal material, with appropriate size, serving as a stimulating electrode and can be regarded as a point electrode. The surface of the metal sphere is welded to the wire. The first metal sphere is exactly fitted into the circular structure on the end plane of the Z-shaped body of the first support rod. The wire extends through the internal hollow tube of the Z-shaped body and passes out through the fine holes on the surface, and is connected to the first outlet of the four-way three-position switch.

[0033] 7. Second metal sphere (E2): The second metal sphere is fitted into the circular structure on the end plane of the Z-shaped body of the second support rod and is connected to the second outlet of the four-way three-position switch; the remaining structure of the second metal sphere is the same as that of the first metal sphere.

[0034] 8. Third metal sphere (E3): The third metal sphere is fitted into the circular structure on the end plane of the Z-shaped body of the third support rod and is connected to the third outlet of the four-way three-position switch; the remaining structure of the third metal sphere is the same as that of the first metal sphere.

[0035] 9. Fourth metal sphere (E4): The fourth metal sphere is fitted into the circular structure on the end plane of the Z-shaped body of the fourth support rod and is connected to the fourth outlet of the four-way three-position switch; the remaining structure of the fourth metal sphere is the same as that of the first metal sphere.

[0036] (III) Voltage signal acquisition module.

[0037] This module includes a signal amplifier and multiple pairs of electrode needles (test electrodes), measures the three-dimensional electric field distribution of the phase interference electric field, measures the electric field strength at the center point between the two needles in this direction through two pairs of electrode needles in the three directions of the X, Y, and Z axes. The recorded voltage signal is transmitted into a multi-channel signal amplifier, and then connected to the A / D in the USB-6361 multi-functional I / O device in the electrical signal transmission module.

[0038] 10. BMA-400 signal amplifier: A four-channel BMA-400 amplifier produced by CWE, Inc. in the United States. Multiple input terminals of the BMA-400 amplifier are connected to the wires of multiple pairs of electrode needles, and the corresponding output terminals are connected to the A / D input terminals of the USB-6361 multi-functional I / O device. After the signal amplifier amplifies the voltage signals in the three directions of the XYZ axes at any point in space recorded by multiple pairs of test electrodes, the analog signals are converted into digital signals through the A / D of the USB-6361 multi-functional I / O device and then input into the microcontroller.

[0039] 11. First pair of electrode needles (X-axis direction): The monopolar electrode needles are test / recording electrodes for measuring the three-dimensional electric field distribution of the phase interference electric field. Two electrode needles form a pair of dipole electrodes. The electrode needles have a certain hardness. Except for small areas at the tip and the tail of the needle, the rest of the surface is evenly coated with an insulating and waterproof coating. Therefore, most of the electrode needles are insulated and waterproof, and only the tip and the tail are conductive. A transparent, insulating and waterproof conical needle sleeve is sleeved on the surface of the electrode needle. The thinnest part of the conical needle sleeve is tightly sleeved at the end of the tip of the electrode needle, and waterproof treatment is carried out here to ensure that the electrode needle does not leak electricity due to the infiltration of external liquid when measuring the electric field distribution, and can protect the electrode needle, thus not affecting the measurement result. The bottom of the conical needle sleeve has a certain thickness and length, and the inner surface of the bottom has threads, and the size matches the external surface threads of the hollow cylindrical protrusion on the bottom surface of the hood-shaped electrode holder on the type III and type IV fixing rods. The first pair of electrode needles are arranged at a certain distance in the X-axis direction, and after the tails of the needles are connected to wires, they are connected to the first input terminal of the BMA-400 type amplifier.

[0040] 12. Second pair of electrode needles (Y-axis direction): The second pair of electrode needles are arranged at a certain distance in the Y-axis direction and are connected to the second input terminal of the BMA-400 type amplifier; the rest of the structure of the second pair of electrode needles is the same as that of the first pair of electrode needles.

[0041] 13. Third pair of electrode needles (Z-axis direction): The third pair of electrode needles are arranged at a certain distance in the Z-axis direction and are connected to the third input terminal of the BMA-400 type amplifier; the rest of the structure of the third pair of electrode needles is the same as that of the first pair of electrode needles.

[0042] (4) Tensile signal acquisition module.

[0043] This module includes a force sensor and a signal transmitter, which collect the tensile force changes generated after the muscle specimen is stimulated by the phase interference electric field. The muscle tensile force is recorded by the force sensor, and the recorded tensile force signal is transmitted into the signal transmitter, and then connected to the A / D in the USB-6361 multifunctional I / O device in the electrical signal transmission module.

[0044] 14. Signal transmitter: A tensile and compressive bidirectional signal transmitter produced by Hyforcell Company, with 2 rows of connection holes at both ends. The left side is connected to the positive and negative power supplies and the A / D in the USB-6361 multifunctional I / O device, and the right side is connected to the force sensor. The signal transmitter amplifies the output signal of the force sensor, and then is converted into an electrical signal recognizable by the computer through the A / D in the USB-6361 multifunctional I / O device.

[0045] 15. Force sensor: A high-precision beam-type force sensor produced by Hyforcell. There are 4 wires at the end of the force sensor, which are connected to the positive and negative poles of the power supply and the signal transmitter respectively. One end of the force sensor has a screw hole for fixation, and the force sensor can be fixed under the sensor-one-dimensional platform fixing plane of the I-shaped fixing rod with the provided screws. There is a vertical hanging ring hook at the lower end of the head of the force sensor. It is vertically suspended, and a muscle can be hung on the vertical ring hook of the force sensor with a cotton thread or a thread made of other materials to record the tensile force change of the muscle during the electrical stimulation process.

[0046] (V) Support module.

[0047] This module includes multiple support rods and a supporting set of multi-dimensional displacement platforms, multiple fixing rods of various different shapes (4 types of fixing rods such as type I, II, III, and IV) and a supporting set of multi-dimensional displacement platforms, as well as a one-dimensional moving platform, an optical plate, a bottom rod, a lifting platform, and a cylindrical container, and realizes four main functions: (1) Changing the electrical signal output mode: The support rod is fixed on the three-dimensional displacement platform, and the support rod is used to fix the metal ball. By adjusting the three-dimensional displacement platform, the spatial position of the metal ball can be arbitrarily changed, so that the electrical signal output mode changes, and different forms of phase interference electric fields are superimposed; (2) Fixing the device for collecting the tensile force signal: The combination of type I and type II fixing rods and the supporting three-dimensional displacement platform is used to fix the force sensor, the muscle specimen, and the one-dimensional moving platform, and the pre-tension before muscle electrical stimulation can be adjusted, and the tensile force change of the muscle during the electrical stimulation process can be recorded; (3) Fixing the electrode needles: The type III fixing rod is used to fix 2 pairs of electrode needles, and the electric field distribution in the XY-axis direction at any point in the phase interference electric field can be measured; the type IV fixing rod is used to fix 1 pair of electrode needles, and the electric field distribution in the Z-axis direction at any point in the phase interference electric field can be measured. The type I and type II fixing rods are combined and fixed on the same supporting three-dimensional displacement platform, and the type III and type IV fixing rods are respectively fixed on the other two supporting three-dimensional displacement platforms. Therefore, the 4 types of fixing rods are 3 sets of independent fixing brackets that can be used separately; (4) Forming a base and a liftable test container: The base structure is composed of an optical plate and a bottom rod. The upper and lower optical plates are fixed as a whole by multiple bottom rods with screws and are stably placed on the workbench; the cylindrical container is fixed on the workbench surface of the lifting platform, and the two form a whole. By adjusting the handwheel of the lifting platform, the spatial position (vertical height) of the cylindrical container can be changed; the lifting platform is fixed on the lower optical plate, and the other components are fixed on the upper optical plate. The base provides a fixed position for each structure.

[0048] 16. The first support rod (S1): It includes a fixed plane and a Z-shaped main body, which are connected at a certain angle. Several fixed holes that match the threaded fixing holes on the working surface of the three-dimensional displacement platform are distributed on the fixed plane; the Z-shaped main body is made of a thin, insulating, waterproof and relatively rigid material, with fine holes evenly distributed on its surface, and is hollow inside to form a hollow tube with a small diameter and an appropriate length. These structures can minimize the influence on the electric field distribution of the phase interference electric field formed by superposition when it is inside the container; the end plane of the Z-shaped main body is a vertical plane with several arc-shaped extensions, thus forming a ring-shaped structure slightly smaller than the diameter of the metal ball. The first support rod is fixed to the first three-dimensional displacement platform.

[0049] 17. The second support rod (S2): The second support rod is fixed to the second three-dimensional displacement platform; the rest of the structure of the second support rod is the same as that of the first support rod.

[0050] 18. The third support rod (S3): The third support rod is fixed to the third three-dimensional displacement platform; the rest of the structure of the third support rod is the same as that of the first support rod.

[0051] 19. The fourth support rod (S4): The fourth support rod is fixed to the fourth three-dimensional displacement platform; the rest of the structure of the fourth support rod is the same as that of the first support rod.

[0052] 20. The first three-dimensional displacement platform (P1, fixing the first support rod S1): The LWD4090 three-dimensional displacement platform produced by TOTEN Company in China can move precisely within a large range on the X, Y, and Z axes of space, with a moving accuracy of 0.1 mm. The three-dimensional displacement platform has a working surface with threaded fixing holes evenly distributed on it, and there is an adjustment handle on each of the three moving axes. By rotating the adjustment handles on the X, Y, and Z axes in sequence, the three-dimensional displacement platform can move along the sliding rails on the X, Y, and Z axes respectively, so as to move within a large space range. The first three-dimensional displacement platform is used to fix the first support rod S1.

[0053] 21. The second three-dimensional displacement platform (P2, fixing the second support rod S2): The second three-dimensional displacement platform is used to fix the second support rod S2; the rest of the structure of the second three-dimensional displacement platform is the same as that of the first three-dimensional displacement platform.

[0054] 22. The third three-dimensional displacement platform (P3, fixing the third support rod S3): The third three-dimensional displacement platform is used to fix the third support rod S3; the rest of the structure of the third three-dimensional displacement platform is the same as that of the first three-dimensional displacement platform.

[0055] 23. The fourth three-dimensional displacement platform (P4, fixing the fourth support rod S4): The fourth three-dimensional displacement platform is used to fix the fourth support rod S4; the rest of the structure of the fourth three-dimensional displacement platform is the same as that of the first three-dimensional displacement platform.

[0056] 24. Type I fixing rod: The Type I fixing rod consists of two mutually perpendicular fixing planes (a three-dimensional platform - rod fixing plane and a sensor - one-dimensional platform fixing plane) and a crossbeam connecting the two fixing planes in the middle. The three-dimensional platform - rod fixing plane is distributed with fixing holes that match the threaded fixing holes on the workbench surface of the three-dimensional displacement platform; on one side of the sensor - one-dimensional platform fixing plane, there are fixing holes that match the fixing plane of the one-dimensional moving platform, and several rows of small fixing holes that match the size of the fixing holes of the force sensor are evenly distributed at the front end below; the main body of the crossbeam is a solid cuboid rod.

[0057] 25. Type II fixing rod: The Type II fixing rod consists of one fixing plane and an L-shaped main body at the lower end. The L-shaped main body is made of a material with insulation, waterproofing, and relatively high strength and stiffness, and has an appropriate length. The L-shaped main body extends vertically downward, and a small horizontal plane extends from its bottom end. There is a small hole in the central area at the end of the horizontal plane. The small hole is vertically aligned with the center point of the annular hook at the lower end of the head of the force sensor. A cotton thread or a thread made of other materials can be used to fix one end of the muscle in this small hole to record the tensile force change of the muscle during the electrical stimulation process.

[0058] 26. Type III fixing rod: The Type III fixing rod consists of one fixing plane, a vertically downward hood-shaped electrode holder, and a connecting rod between the two. The fixing plane of the Type III fixing rod is distributed with fixing holes that match the threaded fixing holes on the workbench surface of the three-dimensional displacement platform; both the hood-shaped electrode holder and the connecting rod are made of a thin and insulating waterproof material. The bottom surface of the hood-shaped electrode holder is a horizontal plane, and there are 4 equally spaced and orthogonally distributed hollow cylindrical protrusions on the bottom surface. The inner surface of the hollow cylindrical protrusions is covered with a conductive coating, and the inner diameter of the hollow part is close to the diameter of the electrode needle; there are threads on the outer surface of the hollow cylindrical protrusions, which match the thread size of the inner surface at the thickest part of the conical needle sleeve of the electrode needle body; the diameter of the connecting rod is smaller and has an appropriate length. There are 4 built-in channels extending upward from the inner surface of the 4 hollow cylindrical protrusions inside the vertical section of the connecting rod. The inner surfaces of the channels are all covered with a conductive coating, and there are 4 corresponding conductive openings at the highest vertical position of the connecting rod, which can be used to connect wires.

[0059] 27. Type Ⅳ fixing rod: The Type Ⅳ fixing rod consists of a fixing plane, a hood-shaped electrode holder facing forward, and a connecting rod between the two. Fixing holes that match the threaded fixing holes on the work surface of the three-dimensional displacement platform are distributed on the fixing plane of the Type Ⅳ fixing rod; both the hood-shaped electrode holder and the connecting rod are made of thin, light, and insulating waterproof materials. The bottom surface of the hood-shaped electrode holder is a vertical surface, and there are two parallel hollow cylindrical protrusions on the bottom surface. The distance between the two protrusions is equal to the distance between the hollow cylindrical protrusions on the bottom surface of the hood-shaped electrode holder of the Type Ⅲ fixing rod. The inner surface of the hollow cylindrical protrusion is covered with a conductive coating, and the inner diameter of the hollow part is similar to the diameter of the electrode needle; there are threads on the outer surface of the hollow cylindrical protrusion, which match the thread size on the inner surface of the thickest part at the bottom of the conical needle sleeve of the electrode needle body; the connecting rod has a smaller diameter and an appropriate length. There are two built-in channels extending upward from the inner surfaces of the two hollow cylindrical protrusions inside the vertical section of the connecting rod. The inner surfaces of the channels are covered with conductive coatings, and there are two corresponding conductive openings at the highest vertical position of the connecting rod, which can be used to connect wires.

[0060] 28. One-dimensional moving platform: It has a fixing plane, a lifting plane, and an adjusting handle. The fixing plane of the one-dimensional moving platform is vertically fixed to the sensor-one-dimensional platform fixing plane of the Type I fixing rod, and the lifting plane is vertically fixed to the fixing plane of the Type II fixing rod, so that the one-dimensional moving platform, the Type I fixing rod, and the Type II fixing rod form an integral body. By rotating the adjusting handle of the one-dimensional moving platform, the lifting plane of the one-dimensional moving platform can move in the vertical direction, while the fixing plane of the one-dimensional moving platform remains stable. Then the Type II fixing rod can be lifted and lowered in the vertical direction, and the Type I fixing rod remains stable, thereby changing the vertical distance between the Type II fixing rod and the force measuring sensor fixed to the Type I fixing rod. Since one end of the muscle specimen is fixed to the vertical annular hook of the force measuring sensor, and the other end is fixed to the thin hole at the end of the horizontal plane at the bottom of the Type II fixing rod, when rotating the adjusting handle of the one-dimensional moving platform, the tightness of both ends of the muscle specimen changes accordingly: the smaller the vertical distance between the Type II fixing rod and the force measuring sensor, the looser the connection between both ends of the muscle specimen; the larger the vertical distance between the Type II fixing rod and the force measuring sensor, the tighter the connection between both ends of the muscle specimen, and the muscle specimen is stretched, thereby adjusting the pre-tension of the muscle specimen before electrical stimulation.

[0061] 29. The fifth three-dimensional displacement platform (P5, fixing the Type I fixing rod): The fifth three-dimensional displacement platform is used to fix the Type I fixing rod; the rest of the structure of the fifth three-dimensional displacement platform is the same as that of the first three-dimensional displacement platform.

[0062] 30. The sixth three-dimensional displacement platform (P6, fixing the Type Ⅲ fixing rod): The sixth three-dimensional displacement platform is used to fix the Type Ⅲ fixing rod; the rest of the structure of the sixth three-dimensional displacement platform is the same as that of the first three-dimensional displacement platform.

[0063] 31. The seventh three-dimensional displacement platform (P7, fixed type-IV fixing rod): The seventh three-dimensional displacement platform is used to fix the type-IV fixing rod; the remaining structure of the seventh three-dimensional displacement platform is the same as that of the first three-dimensional displacement platform.

[0064] 32. Optical plate: It has a certain thickness, large stiffness and strength, is not easily deformed, and has a regular shape. The optical plate is covered with uniformly distributed threaded fixing holes and is divided into two parts: the central area of the upper plate is hollowed out, and the surrounding area is reserved; the lower plate is uniformly complete without hollowing out in the central area, and the bottom of the four corners of the lower plate is supported by pads.

[0065] 33. Bottom rod: It has great strength and stiffness. There are threaded fixing holes at the centers of the upper and lower surfaces of the bottom rod. The sizes of these fixing holes match those of the threaded fixing holes on the optical plate. The upper and lower optical plates and multiple bottom rods are fixed together with screws through the fixing holes and are stably placed on the workbench to form a base structure; there is a knob at the center of the bottom rod, and the length of the bottom rod can be changed by adjusting the knob, thereby changing the distance between the upper and lower optical plates.

[0066] 34. Lifting platform: It includes a handwheel, a high-precision scale, and a workbench surface. By manually adjusting the handwheel and referring to the high-precision scale, the height of the workbench surface of the lifting platform can be finely changed; the workbench surface is uniformly distributed with threaded fixing holes, and the area of the workbench surface is similar to the bottom surface of the cylindrical container.

[0067] 35. Cylindrical container: It is made of insulating and highly rigid materials, is hollow inside, has no cover, and both the surface and the bottom surface have a certain thickness. The bottom surface of the cylindrical container is uniformly distributed with fixing holes, which match the sizes of the fixing holes on the workbench surface of the lifting platform. The cylindrical container can be fixed on the workbench surface of the lifting platform, and the two form an integral body to form a liftable test container. By adjusting the handwheel of the lifting platform, the spatial position (height) of the cylindrical container can be changed. A liquid conductive medium is placed inside the cylindrical container, and its conductivity is similar to that of the muscle specimen.

[0068] 36. Muscle: That is, the muscle specimen. In actual application, a suitable muscle specimen can be selected according to requirements. In Example 2 of the present invention, a single isolated frog gastrocnemius muscle is used as the muscle specimen and is placed in the liquid conductive medium inside the cylindrical container, and the spatial position of the muscle specimen can be adjusted arbitrarily. Since the conductivity of the liquid conductive medium inside the cylindrical container is similar to that of the muscle specimen, when an electrical stimulus is applied, the liquid conductive medium and the muscle specimen can be regarded as a whole. The single isolated muscle placed in the liquid conductive medium is relatively deep in the spatial position and is equivalent to the deep muscle. The stimulation effect of the phase interference electric field output by the stimulation electrode and superimposed inside the cylindrical container on the deep muscle can be evaluated by collecting the tensile signal of the muscle specimen.

[0069] Beneficial effects

[0070] Adopting the technical solution provided by the present invention, compared with the known public technology, it has the following beneficial effects:

[0071] The present invention can measure the three-dimensional electric field distribution of the phase interference electric field and study the influence of the change of the electric field vector direction on the stimulation effect of deep muscles. It integrates the output of stimulation signals, a stable composite support structure, voltage signal acquisition, and tensile signal acquisition. In particular, it can conveniently output two independent alternating current signals above kHz with arbitrary parameters, quickly adjust the circuit output mode, easily change the relative spatial positions of the stimulating electrode, the testing electrode, and the muscle specimen, and directly evaluate the stimulation effect of the phase interference electric field on deep muscles using a single isolated muscle specimen. At the same time, it is an experimental system with stable performance, simple operation, and obvious effects, which is beneficial to the theoretical research work in the field of muscle electrical stimulation; especially the support module in the present invention can be used in combination or alone: through a four-pole three-throw switch, a three-dimensional displacement platform, a supporting rod, and a metal ball fixed on the supporting rod and other structures, the stimulating electrode can be conveniently connected in various forms, so as to quickly change the circuit output mode and adjust the spatial position of the stimulating electrode. Then, the direction characteristics of the phase interference electric field vector formed by the superposition of the outputs of the four stimulating electrodes will change; through various fixing rods with different shapes (such as four types of fixing rods I, II, III, and IV) and supporting three-dimensional displacement platforms, one-dimensional moving platforms and other structures, it is possible to conveniently measure the three-dimensional electric field distribution of the phase interference electric field, fix the muscle specimen and adjust its spatial position, and conveniently adjust the pre-tension of the muscle before electrical stimulation. Description of the Drawings

[0072] Figure 1 It is a connection schematic diagram of the system provided by the present invention (only showing the connection relationship between components). The entire experimental system is placed on the workbench.

[0073] Figure 2 It is a connection schematic diagram of the output of the electrical stimulation signal in the present invention, including a microcontroller 1, a USB-6361 multi-functional I / O device 2, a first A395 linear stimulation isolator 3, a second A395 linear stimulation isolator 4, a four-pole three-throw switch 5, a first metal ball (E1) 6, a second metal ball (E2) 7, a third metal ball (E3) 8, and a fourth metal ball (E4) 9. The two output interfaces, one positive and one negative, corresponding to the first A395 linear stimulation isolator 3 are the A+ and A- ports, and the two output interfaces, one positive and one negative, corresponding to the second A395 linear stimulation isolator 4 are the B+ and B- ports, which are respectively input into the four inlets of the four-pole three-throw switch 5; the four outlets of the four-pole three-throw switch 5 are respectively connected to the four metal balls.

[0074] Figure 3 It is a wiring diagram of the four-pole three-throw switch 5 in the present invention. Figure 3A-3C successively represent three different wiring modes in the four-pole three-throw waveband switch 5, enabling the A+ and A- ports and B+ and B- ports of two A395 linear stimulation isolators 3 and 4 to be connected to four stimulation electrodes E1, E2, E3, and E4 in three different ways. By rotating the knob of the four-pole three-throw waveband switch 5 to different gears, two-channel electrical stimulation signals corresponding to the wiring modes are output, and coherent waves with different electric field vector directions are obtained by superposition. Figure 3 A (Ⅰ), Figure 3 B (Ⅰ) and Figure 3 C (Ⅰ) represent specific wiring modes, Figure 3 A (Ⅱ), Figure 3 B (Ⅱ) and Figure 3 C (Ⅱ) represent the connection relationships between the output ports of two A395 linear stimulation isolators 3 and 4 and the stimulation electrodes.

[0075] Figure 4 This is a schematic diagram of the connection between the voltage signal acquisition module and other components in the present invention, including a BMA-400 signal amplifier 10, a first pair of electrode needles 11, a second pair of electrode needles 12, a third pair of electrode needles 13, a USB-6361 multifunctional I / O device 2, and a microcontroller 1.

[0076] Figure 5 This is a schematic diagram of a single electrode needle in the present invention. Figure 5 A represents a three-dimensional schematic diagram of the electrode needle. Figure 5 B represents the front view of the electrode needle. The tip and a small part of the tail of the electrode needle are conductive ( Figure 5 the blank parts in A and Figure 5 B); the rest of the surface is evenly coated with an insulating and waterproof coating ( Figure 5 the diagonal parts in A and Figure 5 B), and is sleeved with an insulating and waterproof conical needle sleeve. Therefore, most of the electrode needle is insulated and waterproof, and only the tip and the tail are conductive. The present invention uses a total of three pairs of electrode needles, namely the first pair of electrode needles 11, the second pair of electrode needles 12, and the third pair of electrode needles 13. The structures of the above three pairs of electrode needles are all as Figure 5 shown.

[0077] Figure 6 This is a schematic diagram of the connection between the tensile force signal acquisition module and other components in the present invention, including a force sensor 15, a signal transmitter 14, a USB-6361 multifunctional I / O device 2, and a microcontroller 1.

[0078] Figure 7 This is a schematic diagram of a single strut in the present invention. Figure 7 A represents a three-dimensional schematic diagram of the strut. Figure 7 B represents the top view of the strut.

[0079] Figure 8Schematic diagram of the combined use of the first metal ball 6, the first support rod 16 and the first three-dimensional displacement platform 20 in the present invention. Only one group is taken as an example, and the other three groups are the same. Figure 8 A shows the three-dimensional schematic diagram of this combined structure, Figure 8 B shows the side view of this combined structure.

[0080] Figure 9 Schematic diagram of the I-shaped fixing rod 24 in the present invention, Figure 9 A shows the three-dimensional schematic diagram of the I-shaped fixing rod 24, Figure 9 B shows the bottom view of the I-shaped fixing rod 24.

[0081] Figure 10 Schematic diagram of the II-shaped fixing rod 25 in the present invention, Figure 10 A shows the three-dimensional schematic diagram of the inner side of the II-shaped fixing rod 25, Figure 10 B shows the three-dimensional schematic diagram of the outer side of the II-shaped fixing rod 25.

[0082] Figure 11 Schematic diagram of the III-shaped fixing rod 26 in the present invention, Figure 11 A shows the three-dimensional schematic diagram of the III-shaped fixing rod 26, Figure 11 B - D successively show the top view, bottom view and side view of the III-shaped fixing rod 26.

[0083] Figure 12 Schematic diagram of the IV-shaped fixing rod 27 in the present invention, Figure 12 A shows the three-dimensional schematic diagram of the IV-shaped fixing rod 27, Figure 12 B - D successively show the top view, bottom view and side view of the IV-shaped fixing rod 27.

[0084] Figure 13 Schematic diagram of the one-dimensional moving platform 28 in the present invention, Figure 13 A shows the three-dimensional schematic diagram of the one-dimensional moving platform 28, [[ID=4 B shows the front view of the one-dimensional moving platform 28.

[0085] ​ Schematic diagram of the combined use of the force sensor 15, the I-shaped fixing rod 24, the II-shaped fixing rod 25, the one-dimensional moving platform 28 and the fifth three-dimensional displacement platform 29 in the present invention. ​ A - B respectively show the three-dimensional schematic diagram of this combined structure.

[0086] ​ Schematic diagram of the combined use of the first pair of electrode needles 11, the second pair of electrode needles 12, the III-shaped fixing rod 26 and the sixth three-dimensional displacement platform 30 in the present invention, measuring the electric field distribution of the phase interference electric field in the XY-axis direction. ​ A shows the three-dimensional schematic diagram of this combined structure, ​B represents a side view of the combined structure.

[0087] ​ This is a schematic diagram of the combined use of the third pair of electrode needles 13, type-IV fixing rods 27, and the seventh three-dimensional displacement platform 31 in the present invention, for measuring the electric field distribution of the phase interference electric field in the Z-axis direction. ​ A represents a three-dimensional schematic diagram of the combined structure, ​ B represents a side view of the combined structure.

[0088] ​ This is a schematic diagram of the combined use of the optical plate 32 and the bottom rod 33 in the present invention, and the two form a base. The optical plate 32 is divided into upper and lower plates. The central area of the upper plate is hollowed out, and a circle is reserved around it; the central area of the lower plate is not hollowed out, and the bottom of the four corners is supported by pads.

[0089] ​ This is a schematic diagram of the combined use of the lifting platform 34 and the cylindrical container 35 in the present invention, and the two form a liftable test container. ​ A represents a three-dimensional schematic diagram of the combined structure, ​ B - D successively represent the side view, front view, and top view of the combined structure.

[0090] ​ This is the main assembly diagram and position schematic diagram of the experimental system for measuring the three-dimensional electric field distribution in the present invention, showing the assembly and positional relationship among four sets of metal balls 6, 7, 8, 9, support rods 16, 17, 18, 19 and three-dimensional displacement platforms 20, 21, 22, 23, three pairs of electrode needles 11, 12, 13 and their supporting type-III fixing rods 26 and type-IV fixing rods 27, three-dimensional displacement platforms 30, 31, optical plate 32 and bottom rod 33, lifting platform 34 and cylindrical container 35, etc. To clearly and intuitively show the orientation of each structure in the experimental system, except for the optical plate 32, bottom rod 33, and lifting platform 34, the remaining structures are reduced in proportion. ​ A - C successively represent the top view, front view, and three-dimensional schematic diagram of the above combined structure; ​Figure D shows a schematic plan view of the planar positions between the metal balls 6, 7, 8, 9 and the three pairs of electrode needles 11, 12, 13. The intersection point O of the X, Y, and Z axes is the test point. The specific assembly is as follows: The optical plate 32 and the bottom rod 33 form the base. The three-dimensional displacement platforms 20, 21, 22, 23 of the four fixed support rods 16, 17, 18, 19 are installed at the four diagonal corners of the upper plate of the optical plate 32. The three-dimensional displacement platforms 30, 31 of the two fixed type III fixed rods 26 and type IV fixed rods 27 are installed on the opposite sides of the upper plate of the optical plate 32. The cylindrical container 35 and the lifting platform 34 form an integral liftable test container, and the lifting platform 34 is fixed to the lower plate of the optical plate 32. In practical applications: By adjusting the adjustment knobs of the corresponding three-dimensional displacement platforms, the spatial positions of the metal balls 6, 7, 8, 9 and the electrode needles 11, 12, 13 can be arbitrarily changed. Then, by adjusting the handwheel of the lifting platform 34, the cylindrical container 35 filled with the liquid conductive medium is placed at an appropriate height, and the metal balls 6, 7, 8, 9 and the electrode needles 11, 12, 13 are completely immersed in the liquid conductive medium inside the cylindrical container 35, forming a phase interference electric field inside the container, and measuring the three-dimensional electric field distribution. The metal balls 6, 7, 8, 9 are connected to the electrical signal transmission module, and the electrode needles 11, 12, 13 are connected to the voltage signal acquisition module.

[0091] ​ This is the main assembly drawing and position schematic diagram of the electrical stimulation muscle experiment system of the present invention, showing the assembly and positional relationship among the four sets of metal balls 6, 7, 8, 9, the support rods 16, 17, 18, 19 and the three-dimensional displacement platforms 20, 21, 22, 23, the muscle specimen 36, the force sensor 15, the type I fixed rod 24, the type II fixed rod 25, the one-dimensional moving platform 28 and the fifth three-dimensional displacement platform 29, the optical plate 32 and the bottom rod 33, the lifting platform 34 and the cylindrical container 35, etc. To clearly and intuitively show the orientation of each structure in the experimental system, except for the optical plate 32, the bottom rod 33 and the lifting platform 34, the other structures are reduced in equal proportion. ​ A - C successively represent the top view, the front view and the three-dimensional schematic diagram of the above combined structure; ​D shows a schematic diagram of the planar position between the metal balls 6, 7, 8, 9 and the muscle specimen 36. The specific assembly is as follows: The optical plate 32 and the bottom rod 33 form a base. The three-dimensional displacement platforms 20, 21, 22, 23 of the four fixed support rods 16, 17, 18, 19 are installed at the four diagonals of the upper plate of the optical plate 32. The three-dimensional displacement platform 29 for fixing the type I fixing rod 24, the type II fixing rod 25, the one-dimensional moving platform 28 and the force measuring sensor 15 is installed on one side of the upper plate of the optical plate 32. The cylindrical container 35 and the lifting platform 34 form an integral liftable test container, and the lifting platform 34 is fixed to the lower plate of the optical plate 32. In practical applications: By adjusting the adjustment knobs of the corresponding three-dimensional displacement platforms, the spatial positions of the metal balls 6, 7, 8, 9 and the muscle specimen 36 can be arbitrarily changed. Then, by adjusting the handwheel of the lifting platform 34, the cylindrical container 35 filled with the conductive medium is set at an appropriate height, and the metal balls 6, 7, 8, 9 and the muscle specimen 36 are completely immersed in the liquid conductive medium inside the cylindrical container 35, forming a phase interference electric field inside the container, and studying the electrostimulation effect of the change in the vector direction of the phase interference electric field on the deep muscle. The metal balls 6, 7, 8, 9 are connected to the electrical signal transmission module, and the force measuring sensor 15 is connected to the tensile signal acquisition module.

[0092] Explanation of the reference numerals in the figure:

[0093] 1. Computer; 2. USB-6361 multi-functional I / O device; 3. First A395 linear stimulation isolator; 4. Second A395 linear stimulation isolator; 5. Four-pole triple-throw band switch; 6. First metal ball; 7. Second metal ball; 8. Third metal ball; 9. Fourth metal ball; 10. BMA-400 signal amplifier; 11. First pair of electrode needles (in the X-axis direction); 12. Second pair of electrode needles (in the Y-axis direction); 13. Third pair of electrode needles (in the Z-axis direction); 14. Signal transmitter; 15. Force measuring sensor; 16. First support rod; 17. Second support rod; 18. Third support rod; 19. Fourth support rod; 20. First three-dimensional displacement platform; 21. Second three-dimensional displacement platform; 22. Third three-dimensional displacement platform; 23. Fourth three-dimensional displacement platform; 24. Type I fixing rod; 25. Type II fixing rod; 26. Type III fixing rod; 27. Type IV fixing rod; 28. One-dimensional moving platform; 29. Fifth three-dimensional displacement platform; 30. Sixth three-dimensional displacement platform; 31. Seventh three-dimensional displacement platform; 32. Optical plate; 33. Bottom rod; 34. Lifting platform; 35. Cylindrical container; 36. Muscle. Specific implementation method

[0094] The content of the present invention is to provide an experimental system for electrostimulation of muscles, including two functions: measuring the three-dimensional electric field distribution of the phase interference electric field and displaying the electrostimulation effect of the change in the vector direction of the phase interference electric field in space on the deep muscle.

[0095] To achieve the above object, the present invention provides the following technical solutions:

[0096] The present invention provides an experimental system for electrically stimulating muscles, comprising a microcontroller, an electrical signal transmission module, a voltage signal acquisition module, a tensile force signal acquisition module, and a support module.

[0097] The microcontroller is used to generate an electrical stimulation signal, the electrical stimulation signal being a sine signal, and to process and analyze the three-dimensional electric field distribution of the phase interference electric field, that is, the voltage signals at two points in the XYZ directions of any point in space of the phase interference electric field at this point, as well as the muscle tensile force signal;

[0098] The electrical signal transmission module is used to output the electrical stimulation signal and to acquire the voltage and muscle tensile force signals; during the process of outputting the electrical stimulation signal, the electrical signal transmission module receives the electrical stimulation signal generated by the microcontroller, and is provided with two circuits for outputting the electrical stimulation signal, and the output modes of the two circuits can be quickly changed, that is, the output modes of the two sine signals can be quickly changed, so as to form coherent wave signals with different vector directions in space by superposition; during the process of acquiring the voltage signal, the electrical signal transmission module converts the voltage analog signal recorded by the voltage signal acquisition module into a voltage digital signal and then inputs it into the microcontroller; during the process of acquiring the muscle tensile force signal, the electrical signal transmission module converts the tensile force analog signal recorded by the tensile force signal acquisition module into a tensile force digital signal and then inputs it into the microcontroller;

[0099] The voltage signal acquisition module is used to acquire the voltage signals at two points in the XYZ directions of any point in space of the phase interference electric field at a certain point; when the voltage signal acquisition module acquires the voltage signals at two points in the X direction of any point, it actually means acquiring the voltage between two very small distance points on both sides of this point in the X direction, and dividing the voltage between the two points by the distance between the two points to obtain the electric field strength at the middle point, and acquiring the voltage signals at two points in the Y and Z directions in space in the same principle, so as to measure the three-dimensional electric field distribution of the phase interference electric field; the voltage signal acquisition module transmits the acquired voltage signal data to the electrical signal transmission module and then inputs it into the microcontroller;

[0100] The tensile force signal acquisition module is used to acquire the muscle tensile force signal, and transmits the acquired tensile force signal data to the electrical signal transmission module and then inputs it into the microcontroller;

[0101] The support module is used to form a stable support structure to fix multiple metal balls (stimulating electrodes), multiple pairs of electrode needles (testing electrodes), a force sensor, a muscle specimen, and a one-dimensional moving platform in space, and the spatial positions of the stimulating electrodes can be changed arbitrarily; the support module provides a hollow liftable insulating container, which is used to fill a liquid conductive medium, and the alternating current signals above kilohertz output via the stimulating electrodes are superimposed in the liquid conductive medium inside the container to form a phase interference electric field; the base structure in the support module is used to provide fixed sites for each structure in the present invention.

[0102] The electrical signal transmission module is connected to the microcontroller;

[0103] The voltage signal acquisition module and the tensile force signal acquisition module are respectively connected to the electrical signal transmission module;

[0104] The above voltage signal acquisition module includes multiple pairs of independent electrode needles (testing electrodes) and signal amplifiers; one pair of electrode needles is used as a pair of testing electrodes, the first pair of electrode needles is in the X-axis direction, the second pair of electrode needles is in the Y-axis direction, and the third pair of electrode needles is in the Z-axis direction. The distance between each pair of electrode needles is the same, and there are 3 pairs of independent testing electrodes in total. The three-dimensional electric field distribution of the phase interference electric field is measured by the paired electrode needles in the three directions of the X, Y, and Z axes; the input end of the signal amplifier is connected to the electrode needles, and the output end is connected to the analog-to-digital (A / D) conversion of the input / output (I / O) device; after the signal amplifier amplifies the voltage signal recorded by the electrode needles, it outputs to the A / D to convert the analog signal into a digital signal, and then inputs it into the microcontroller;

[0105] The above tensile force signal acquisition module includes a force sensor and a signal transmitter; the force sensor is fixedly suspended with a cotton thread or a thread of other materials at one end of the muscle to measure the muscle tensile force data; the input end of the signal transmitter is connected to the force sensor, and the output end is connected to the A / D of the I / O device; the signal transmitter amplifies the output signal of the force sensor, outputs to the A / D to convert the analog signal into a digital signal, and then inputs it into the microcontroller;

[0106] The above support module includes multiple support rods and a supporting set of multiple three-dimensional displacement platforms, multiple fixing rods of various different shapes (such as four types of fixing rods of type I, II, III, and IV) and a supporting set of multiple three-dimensional displacement platforms, as well as a one-dimensional moving platform, an optical plate, a bottom rod, a lifting platform, and a cylindrical container;

[0107] The support rod includes a fixed plane and a Z-shaped body. There is an angle between the fixed plane and the Z-shaped body. Several fixing holes that match the threaded fixing holes on the working surface of the three-dimensional displacement platform are distributed on the fixed plane. The Z-shaped body of the support rod is made of a thin, lightweight, insulating, waterproof, and relatively high-rigidity material. Fine holes are evenly distributed on the surface, and the interior is hollow to form a hollow tube with a small diameter and an appropriate length, so that when the Z-shaped body of the support rod is inside the container, the influence on the electric field distribution of the phase interference electric field formed by superposition is minimized. There are several arc-shaped extensions on the end plane of the Z-shaped body of the support rod, forming a ring-shaped structure slightly smaller than the diameter of the metal ball. A total of four support rods are provided and are sequentially fixed on the supporting three-dimensional displacement platform.

[0108] The three-dimensional displacement platform can perform precise movement with a large stroke on the XYZ three axes. Multiple threaded fixing holes are distributed on the working surface of the three-dimensional displacement platform. By sequentially rotating the adjustment knobs on the XYZ three axes of the three-dimensional displacement platform, it can move along the slide rails on the XYZ three axes respectively, so that the three-dimensional displacement platform can move within a large spatial range. A total of seven three-dimensional displacement platforms are provided. Four of the three-dimensional displacement platforms are used to fix the supporting rods, and three are used to fix four types of fixing rods.

[0109] The three-dimensional displacement platform and the supporting rod are fixed as a whole through the fixing holes. The metal ball is exactly fitted into the ring-shaped structure on the bottom plane of the support rod. The wire extends through the hollow interior of the Z-shaped body and passes out through the fine holes on the surface and is connected to the outlet of the four-way three-position switch.

[0110] The support rod, the three-dimensional displacement platform, and the metal ball form a whole. A total of four sets are provided. By rotating the adjustment knob of the three-dimensional displacement platform, the corresponding metal ball can be moved arbitrarily in space.

[0111] The fixing rods are divided into four types: type I, type II, type III, and type IV, and are all integrally formed by 3D printing.

[0112] The type I and type II fixing rods are used in combination to fix the force sensor, the muscle specimen, and the one-dimensional moving platform.

[0113] The type III fixing rod is used to fix 2 pairs of electrode needles to measure the electric field distribution at any point in the XY axis direction in the phase interference electric field.

[0114] The type IV fixing rod is used to fix 1 pair of electrode needles to measure the electric field distribution at any point in the Z axis direction in the phase interference electric field.

[0115] The type-I fixing rod is composed of two mutually perpendicular fixing planes (a three-dimensional platform-rod fixing plane and a sensor-one-dimensional platform fixing plane) and a cross beam in the middle. On the three-dimensional platform-rod fixing plane, there are fixing holes that match the threaded fixing holes on the workbench surface of the three-dimensional displacement platform for mechanical connection between the two. On one side surface of the sensor-one-dimensional platform fixing plane, there are fixing holes that match the threaded fixing holes on the fixing plane of the one-dimensional moving platform for mechanical connection between the two. Below the sensor-one-dimensional platform fixing plane, a plurality of small fixing holes that match the fixing holes of the force sensor are evenly distributed for mechanical connection between the two;

[0116] The type-II fixing rod is composed of one fixing plane and an L-shaped main body at the lower end. The L-shaped main body is made of a thin, lightweight, insulating, waterproof and relatively rigid material, with a hollow interior forming a hollow tube, having a smaller diameter and an appropriate length. The L-shaped main body extends vertically downward, and a small horizontal plane extends from its bottom end, and there is a small hole in the central area at the end of the horizontal plane;

[0117] The type-III fixing rod is composed of one fixing plane, a hood-shaped electrode holder extending vertically downward, and a connecting rod between the two. The hood-shaped electrode holder and the connecting rod are both made of thin, lightweight and insulating waterproof materials. The bottom surface of the hood-shaped electrode holder is a horizontal plane, and there are 4 equally spaced and orthogonally distributed hollow cylindrical protrusions on the bottom surface. The inner surface of the hollow cylindrical protrusion is a conductive coating, and the pore diameter of the hollow cylindrical protrusion is close to the diameter of the electrode needle; the outer surface of the hollow cylindrical protrusion has threads that match the threads on the inner surface of the thickest part at the bottom of the tapered needle sleeve of the electrode needle body; the connecting rod has a smaller diameter and an appropriate length, with small holes evenly distributed on its surface, and there are 4 built-in channels extending from the inner surfaces of the 4 hollow cylindrical protrusions inside. The inner surfaces of the channels are all covered with conductive coatings, and there are 4 corresponding conductive openings at the highest vertical position of the connecting rod for connecting wires;

[0118] The Type-IV fixing rod is composed of a fixing plane, a forward-facing hood-shaped electrode holder, and a connecting rod between the two. The hood-shaped electrode holder and the connecting rod are both made of thin, lightweight, and insulating waterproof materials. The bottom surface of the hood-shaped electrode holder is a vertical plane, and there are two parallel hollow cylindrical protrusions on the bottom surface. The distance between the two protrusions is equal to the distance between the hollow cylindrical protrusions on the bottom surface of the hood-shaped electrode holder of the Type-III fixing rod. The inner surface of the hollow cylindrical protrusion is covered with a conductive coating, and the inner diameter of the hollow part is close to the diameter of the electrode needle. The outer surface of the hollow cylindrical protrusion has threads that match the thread size of the thickest part of the inner surface of the conical needle sleeve of the electrode needle body. The connecting rod has a smaller diameter and an appropriate length, with fine holes evenly distributed on its surface. There are two built-in channels extending from the inner surfaces of the two hollow cylindrical protrusions inside. The inner surfaces of the channels are both covered with a conductive coating, and there are two corresponding conductive openings at the highest vertical position of the connecting rod for connecting wires.

[0119] The Type-I and Type-II fixing rods are combined and fixed on the same supporting three-dimensional displacement platform, while the Type-III and Type-IV fixing rods are respectively fixed on the other two supporting three-dimensional displacement platforms.

[0120] The four types of fixing rods and their supporting three-dimensional displacement platforms are three sets of independent fixing brackets that can be used separately.

[0121] The one-dimensional moving platform has a fixing plane, a lifting plane, and an adjusting handle. The fixing plane of the one-dimensional moving platform is vertically fixed to the sensor-one-dimensional platform fixing plane of the Type-I fixing rod, and the lifting plane is vertically fixed to the fixing plane of the Type-II fixing rod. By rotating the adjusting handle of the one-dimensional moving platform, the Type-II fixing rod can be lifted and lowered in the vertical direction.

[0122] The optical plate is covered with evenly distributed threaded fixing holes. The optical plate has high stiffness and strength, is not easily deformed, and has a regular shape. The optical plate is divided into upper and lower parts. The central area of the upper plate is hollowed out, and the surrounding area is reserved. The lower plate has a uniform thickness and is not hollowed out. There are support pads at the bottoms of the four corners of the lower plate.

[0123] The bottom rod has great strength and stiffness. There are fixing holes at the centers of the upper and lower surfaces, and the sizes of these holes match the fixing holes on the optical plate. There is a knob at the center of the rod, and the length of the rod can be changed by adjusting the knob. A total of four bottom rods are provided.

[0124] The upper and lower optical plates and multiple bottom rods are fixed into a whole with screws through the fixing holes and are stably placed on the workbench to form a base structure.

[0125] The lifting table includes a handwheel, a high-precision scale, and a workbench surface. The workbench surface is evenly distributed with fixing holes, and the area of the workbench surface is close to the bottom surface of the cylindrical container.

[0126] The surface and bottom surface of the cylindrical container have a certain thickness, and fixing holes are evenly distributed on the bottom surface but do not penetrate the bottom surface;

[0127] The interior of the cylindrical container is a liquid conductive medium;

[0128] The fixing holes on the workbench surface of the lifting table match the fixing holes on the bottom surface of the cylindrical container, and the cylindrical container can be fixed on the workbench surface of the lifting table. The two form an integral body, and by adjusting the handwheel of the lifting table, the spatial position (vertical height) of the cylindrical container can be changed;

[0129] The lifting table and the cylindrical container constitute a liftable insulating container;

[0130] A further setting of the present invention is that the electrical signal transmission module includes an I / O device, a linear stimulation isolator, a four-way three-position switch, and metal balls, where:

[0131] The I / O device is respectively connected to the microprocessor and the linear stimulation isolator, and the I / O device is connected to the microcontroller through a USB interface; when outputting an electrical stimulation signal, the D / A in the I / O device converts the digital signal generated in the microcontroller into an analog signal, and then transmits the electrical stimulation signal to the linear stimulation isolator through the output interface; when measuring the three-dimensional electric field distribution of the phase interference electric field, the A / D in the I / O device converts the analog signal recorded by the signal amplifier in the voltage signal acquisition module into a digital signal, and then transmits the voltage signal to the microcontroller through the input interface; when recording the change in the pulling force generated after the muscle specimen is stimulated by the phase interference electric field, the A / D in the I / O device converts the pulling force analog signal recorded by the signal transmitter in the pulling force signal acquisition module into a digital signal, and then transmits the pulling force signal to the microcontroller through the input interface;

[0132] The linear stimulation isolator is used to output a stimulation current with stable intensity. There are two linear stimulation isolators in total. The input end of the linear stimulation isolator is connected to the D / A output interface of the I / O device that outputs a sine signal, and the output end of the linear stimulation isolator is connected to the incoming line port of the four-way three-position switch in the electrical signal transmission module, outputting two sine alternating current signals in kHz;

[0133] The four-way three-position switch has a total of four incoming line ports, four outgoing line ports, and three rotatable blades. The four incoming line ports of the four-way three-position switch are connected to the output ends of the two linear stimulation isolators, the four outgoing line ports of the four-way three-position switch are connected to the wires connecting the four metal balls, and different circuits can be connected after the three rotatable blades of the four-way three-position switch are adjusted.

[0134] The metal balls are used to output electrical stimulation signals. The metal balls are made of spherical metal materials, with appropriate sizes, and their surfaces are connected to wires to serve as stimulation electrodes. Four metal balls are provided in total and are sequentially connected to the four outlet ports of a four-pole triple-throw switch. The metal balls are all fixed on corresponding support rods.

[0135] The above-mentioned microcontroller, electrical signal transmission module, voltage signal acquisition module, and tensile force signal acquisition module are respectively connected to a power supply.

[0136] Term Explanation

[0137] Three-dimensional electric field distribution of the phase interference electric field: The electric field intensities of the phase interference electric field at any point in space in the X, Y, and Z-axis directions at that point.

[0138] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described 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 making creative efforts shall fall within the protection scope of the present invention.

[0139] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0140] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0141] The content of the present invention is to provide an experimental system for electrical stimulation of muscles. In order to show the stimulation effect of the change in the direction of the phase interference electric field vector on muscles, first, it is necessary to measure the three-dimensional electric field distribution of the phase interference electric field, and then study the change in the electrical stimulation effect on muscles caused by the change in the direction of the electric field vector. Therefore, the present invention has two functions: 1. Measuring the three-dimensional electric field distribution of the phase interference electric field; 2. Showing the electrical stimulation effect of the change in the direction of the phase interference electric field vector in space on deep muscles. The present invention realizes the above two functions through two independent test processes, so as to show the stimulation effect of the change in the direction of the phase interference electric field vector on muscles. Each test process has its corresponding structural setting, and the corresponding structure can be disassembled or assembled according to the test purpose and the order of the tests.

[0142] Embodiment 1 Assembly and demonstration of the experimental system for measuring the three-dimensional electric field distribution of the present invention

[0143] As ​ 、 ​ 、 ​ and ​ shown, the present invention provides an experimental system for measuring the three-dimensional electric field distribution of the phase interference electric field, including a microcontroller, an electrical signal transmission module, a voltage signal acquisition module, and a support module;

[0144] The microcontroller 1 is used to generate two alternating current stimulation signals above kHz and record the measurement of the three-dimensional electric field distribution of the phase interference electric field, that is, the electric field intensities of the phase interference electric field at any point in space in the XYZ directions at this point. The measurement of the electric field intensity in the X direction at this point is the voltage between two points with similar distances along the X direction divided by the distance between the two points. Therefore, the electric field intensity is calculated from the measured voltage signal.

[0145] The electrical signal transmission module is used to output the electrical stimulation signal and collect the voltage signal. Output the electrical stimulation signal: used to receive the electrical stimulation signal generated by the microcontroller 1, output two alternating current stimulation signals above kHz, the output mode of the electrical stimulation signal can be quickly changed, the spatial position of the stimulation electrode can be arbitrarily changed, and the coherent wave signal is formed by superposition; Collect the voltage signal: when measuring the three-dimensional electric field distribution of the phase interference electric field, convert the voltage analog signal recorded by the voltage signal acquisition module into a voltage digital signal and then input it into the microcontroller 1; The electrical signal transmission module is connected to the microcontroller 1;

[0146] The voltage signal acquisition module is used to collect the voltage signals of the phase interference electric field at any point in space in the XYZ directions at a certain point, and then input the voltage signal data into the electrical signal transmission module; The voltage signal acquisition module is connected to the electrical signal transmission module;

[0147] The support module is used to provide a base for fixing the present invention, fix the stimulating electrode and the testing electrode, and provide a liftable cylindrical insulating container filled with a conductive medium. Two alternating current stimulating signals above kHz output via the stimulating electrode are superimposed in the container to form a phase interference electric field;

[0148] In Embodiment 1, the microcontroller 1 used is a computer. Stimulating signals are written in the computer MATLAB software, and two alternating current signals above kHz are output. The parameters of the stimulating signals can be adjusted arbitrarily, and the three-dimensional electric field distribution of the phase interference electric field formed by different stimulating signals is measured;

[0149] In Embodiment 1, the electrical signal transmission module includes a USB-6361 multifunctional I / O device 2, two A395 linear stimulating isolators 3 and 4, a four-pole three-throw band switch 5, and four metal balls 6, 7, 8, 9, where:

[0150] The USB-6361 multifunctional I / O device 2 is connected to the microcontroller 1 through a USB interface. When outputting an electrical stimulating signal, the USB-6361 multifunctional I / O device 2 converts the digital signal generated in the microcontroller 1 into an analog signal, and then transmits the electrical stimulating signal to the A395 linear stimulating isolator 3 through the output interface; the USB-6361 multifunctional I / O device 2 converts the voltage analog signal recorded by the BMA-400 signal amplifier 10 into a digital signal and inputs it into the microcontroller 1.

[0151] The two A395 linear stimulating isolators 3 and 4 are used to output a constant stimulating current. There are two A395 linear stimulating isolators in total: the input interface of the first A395 linear stimulating isolator 3 is connected to the first pair of output interfaces of the USB-6361 multifunctional I / O device 2, and the output interface (two output interfaces, one positive and one negative, are the A+ and A- ports) is connected to two of the incoming wire ports of the four-pole three-throw band switch 5; the input interface of the second A395 linear stimulating isolator 4 is connected to the second pair of output interfaces of the USB-6361 multifunctional I / O device 2, and the output interface (two output interfaces, one positive and one negative, are the B+ and B- ports) is connected to the other two incoming wire ports of the four-pole three-throw band switch 5; by setting two A395 linear stimulating isolators, two independent alternating current signals above kHz can be output.

[0152] The four-pole three-position band switch 5 is used to quickly change the output form of two alternating current signals above kHz, and the direction of the phase interference electric field vector formed by superposition in space changes. The four inlets of the four-pole three-position band switch 5 are connected to the A+ and A- ports of the first A395 linear stimulation isolator 3 and the B+ and B- ports of the second A395 linear stimulation isolator 4. The four outlets of the four-pole three-position band switch 5 are connected to four metal balls (E1, E2, E3, E4) 6, 7, 8, and 9. There are a total of 3 wiring methods. By rotating the knob of the four-pole three-position band switch 5 to the first / second / third gear, the two electric signals output from the two A395 linear stimulation isolators 3 and 4 are respectively transmitted to the corresponding metal balls according to the preset 3 wiring methods. Specifically: (1) The A+ port is connected to E1, the A- port is connected to E2, the B+ port is connected to E3, and the B- port is connected to E4, that is, an electric signal is output on the metal balls (E1, E2) 6 and 7, and another electric signal is output on the metal balls (E3, E4) 8 and 9; (2) The A+ port is connected to E1, the A- port is connected to E3, the B+ port is connected to E2, and the B- port is connected to E4, that is, an electric signal is output on the metal balls (E1, E3) 6 and 8, and another electric signal is output on the metal balls (E2, E4) 7 and 9; (3) The A+ port is connected to E1, the A- port is connected to E4, the B+ port is connected to E3, and the B- port is connected to E2, that is, an electric signal is output on the metal balls (E1, E4) 6 and 9, and another electric signal is output on the metal balls (E3, E2) 8 and 7.

[0153] The four metal balls (E1, E2, E3, E4) 6, 7, 8, and 9 serve as stimulation electrodes and are connected to the four outlets of the four-pole three-position band switch 5. During the test, they are placed inside a container filled with a conductive medium to output two alternating current signals above kHz to form a phase interference electric field.

[0154] In Embodiment 1, the voltage signal acquisition module includes a BMA-400 signal amplifier 10, a first pair of electrode needles (in the X-axis direction) 11, a second pair of electrode needles (in the Y-axis direction) 12, and a third pair of electrode needles (in the Z-axis direction) 13, where:

[0155] The three input ends of the BMA-400 signal amplifier 10 are connected to the wires of the three pairs of electrode needles, and the output end is connected to the A / D input end of the USB-6361 multifunctional I / O device 2. After the BMA-400 signal amplifier 10 amplifies the voltage signals in the three directions of the X, Y, and Z axes at the measurement points recorded by the multiple pairs of electrode needles, the analog signals are converted into digital signals through the A / D of the USB-6361 multifunctional I / O device 2 and then input into the microcontroller 1 for data processing and analysis.

[0156] The three pairs of electrode needles 11, 12, and 13 have the same structure. They are conductive only at the tip and the tail, and are all dipole electrodes. They are respectively fixed inside the hollow cylindrical protrusions on the bottom surface of the hood-shaped electrode holder on the type III and type IV fixing rods. There are matching threads between them that can be tightened, and the connection is treated with waterproof insulation to avoid affecting the measurement results. The tips of the three pairs of electrode needles 11, 12, and 13 measure the three-dimensional electric field distribution of the measured points, and the tails are connected to the input end of the BMA-400 signal amplifier 10 after being connected to wires.

[0157] The first pair of electrode needles (in the X-axis direction) 11 is inserted into the hollow cylindrical protrusion in the X-axis direction on the bottom surface of the hood-shaped electrode holder on the type III fixing rod, and is arranged at a certain distance in the X-axis direction. The tail is connected to the first input end of the BMA-400 signal amplifier 10 after being connected to a wire;

[0158] The second pair of electrode needles (in the Y-axis direction) 12 is inserted into the hollow cylindrical protrusion in the Y-axis direction on the bottom surface of the hood-shaped electrode holder on the type III fixing rod, and is arranged at a certain distance in the Y-axis direction. The tail is connected to the second input end of the BMA-400 signal amplifier 10 after being connected to a wire;

[0159] The third pair of electrode needles (in the Z-axis direction) 13 is inserted into the hollow cylindrical protrusion on the bottom surface of the hood-shaped electrode holder on the type IV fixing rod, and is arranged at a certain distance in the Z-axis direction. The tail is connected to the third input end of the BMA-400 signal amplifier 10 after being connected to a wire.

[0160] In Embodiment 1, the support module includes the first support rod 16, the second support rod 17, the third support rod 18, the fourth support rod 19, the first three-dimensional displacement platform 20, the second three-dimensional displacement platform 21, the third three-dimensional displacement platform 22, and the fourth three-dimensional displacement platform 23, where:

[0161] The four support rods 16, 17, 18, and 19 have the same structure, and are all fixed on the workbenches of the corresponding four three-dimensional displacement platforms 20, 21, 22, and 23 through the threaded holes on the fixed plane; the end planes of the Z-shaped bodies of the four support rods 16, 17, 18, and 19 are vertical, and there are several arc-shaped extensions on the plane, forming a ring-shaped structure slightly smaller than the diameter of the metal ball. The four metal balls 6, 7, 8, and 9 are respectively fitted and fixed in the ring-shaped structures of the corresponding four support rods 16, 17, 18, and 19;

[0162] The four three-dimensional displacement platforms 20, 21, 22, and 23 have the same structure and can move precisely within a large range on the three spatial axes of X, Y, and Z. There is an adjustment handle on each of the three moving axes. By sequentially rotating the adjustment handles on the X, Y, and Z axes, the three-dimensional displacement platform can be moved along the slide rails on the X, Y, and Z axes respectively, so as to move within a large spatial range.

[0163] The first support rod 16 is fixed to the first three-dimensional displacement platform 20, and the metal ball 6 is fixed to the first support rod 16.

[0164] The second support rod 17 is fixed to the second three-dimensional displacement platform 21, and the metal ball 7 is fixed to the second support rod 17;

[0165] The third support rod 18 is fixed to the third three-dimensional displacement platform 22, and the metal ball 8 is fixed to the third support rod 18;

[0166] The fourth support rod 19 is fixed to the fourth three-dimensional displacement platform 23, and the metal ball 9 is fixed to the fourth support rod 19.

[0167] By adjusting the adjustment handle of the three-dimensional displacement platform, the support rod can be finely moved in space, so that the spatial position of the metal ball can be arbitrarily adjusted.

[0168] In Embodiment 1, the support module further includes a type-III fixing rod 26, a type-IV fixing rod 27, a sixth three-dimensional displacement platform 30, and a seventh three-dimensional displacement platform 31, where:

[0169] The type-III fixing rod 26 is fixed to the working surface of the sixth three-dimensional displacement platform 30 through a threaded hole on the fixing plane. There is a downward-facing hood-shaped electrode holder on the type-III fixing rod 26. Its bottom surface is horizontal and has 4 equally spaced and orthogonally distributed hollow cylindrical protrusions. The inner surface of the protrusion is covered with a conductive coating and extends upward to form an internal channel, which opens at the vertical highest point of the connecting rod. The first pair of electrode needles 11 is inserted into the hollow cylindrical protrusion in the X-axis direction, and the second pair of electrode needles 12 is inserted into the hollow cylindrical protrusion in the Y-axis direction. The tail of the electrode needle is in close contact with the inner surface of the hollow cylindrical protrusion, and a wire is welded at the opening and connected to the input end of the BMA-400 signal amplifier 10;

[0170] The type-IV fixing rod 27 is fixed to the working surface of the seventh three-dimensional displacement platform 31 through a threaded hole on the fixing plane. There is a forward-facing hood-shaped electrode holder on the type-IV fixing rod 27. Its bottom surface is vertical and has 2 parallel hollow cylindrical protrusions. The inner surface of the protrusion is covered with a conductive coating and extends upward to form an internal channel, which opens at the vertical highest point of the connecting rod. The third pair of electrode needles 13 is inserted into the hollow cylindrical protrusion, and the tail of the needle is in close contact with the inner surface of the hollow cylindrical protrusion. A wire is welded at the opening and connected to the third input end of the BMA-400 signal amplifier 10.

[0171] Type III fixing rods 26 are used to secure two pairs of electrode needles 11 and 12, measuring the electric field distribution along the X and Y axes at any point in the phase interference electric field. Type IV fixing rods 27 are used to secure a third pair of electrode needles 13, measuring the electric field distribution along the Z axis at any point in the phase interference electric field. Type III fixing rods 26 and Type IV fixing rods 27 are respectively secured to matching three-dimensional displacement platforms 30 and 31, forming two sets of test stands that can be used in combination or independently.

[0172] In Example 1, the support module further includes an optical plate 32, a bottom rod 33, a lifting platform 34, and a cylindrical container 35, wherein:

[0173] The optical plate 32 is divided into an upper plate and a lower plate, both of which are evenly spaced with threaded fixing holes. The central area of the upper plate is hollowed out, and a circle around it is retained to form a U-shaped; the lower plate is complete, and the four diagonal bottoms of the lower plate are supported by pads.

[0174] The bottom rods 33 have threaded holes on their upper and lower surfaces. Four bottom rods 33 are screwed to the four diagonal corners of the upper and lower optical plates 32. This secures the upper and lower optical plates 32 and the four bottom rods 33 together to form a base structure that can be placed stably on a workbench. Adjusting the knob in the center of the bottom rod 33 adjusts the rod's length, thereby adjusting the distance between the upper and lower optical plates.

[0175] The lifting platform 34 includes a hand wheel, a high-precision ruler and a work surface. By manually adjusting the hand wheel against the high-precision ruler, the height of the work surface of the lifting platform 34 can be finely changed.

[0176] The cylindrical container 35 is hollow and uncovered. It is fixed to the work surface of the lifting platform 34, forming a single unit that can be raised or lowered. Adjusting the lifting platform 34's handwheel allows the vertical height of the cylindrical container 35 to be quickly adjusted. During measurement, the cylindrical container 35 is filled with a liquid conductive medium.

[0177] The first three-dimensional displacement platform 20, the second three-dimensional displacement platform 21, the third three-dimensional displacement platform 22 and the fourth three-dimensional displacement platform 23 are installed at the four diagonal corners of the upper plate of the optical plate 32; the sixth three-dimensional displacement platform 30 and the seventh three-dimensional displacement platform 31 are installed on the opposite sides of the upper plate of the optical plate 32; the lifting platform 34 is installed on the lower plate of the optical plate 32; the base structure composed of the optical plate 32 and the bottom rod 33 provides a fixed position for the above-mentioned multiple three-dimensional displacement platforms.

[0178] During the experiment of measuring the three-dimensional electric field distribution, the microcontroller 1 outputs two alternating current stimulation signals above kilohertz to the electrical signal transmission module, and receives the three-dimensional electric field distribution of the phase interference electric field measured by the voltage signal acquisition module. By adjusting the adjustment handle of the three-dimensional displacement platform, the spatial positions of the metal balls 6, 7, 8, 9 and the electrode needles 11, 12, 13 can be arbitrarily changed. Then, by adjusting the handwheel of the lifting platform 34, the cylindrical container 35 filled with the conductive medium is raised, and the metal balls 6, 7, 8, 9 and the electrode needles 11, 12, 13 are completely immersed inside the cylindrical container 35, forming a phase interference electric field inside the container, and measuring the three-dimensional electric field distribution.

[0179] Example 2 Assembly and Demonstration of the Muscle Electrical Stimulation Contraction Experimental System of the Present Invention

[0180] As ​ 、 ​ 、 ​ 、 ​ and ​ shown, the present invention provides an experimental system for muscle electrical stimulation contraction, including a microcontroller, an electrical signal transmission module, a tensile signal acquisition module and a support module;

[0181] The microcontroller 1 is used to generate two alternating current stimulation signals above kilohertz and record the tensile signals of muscle electrical stimulation.

[0182] The electrical signal transmission module is used to output electrical stimulation signals and acquire tensile signals. Output electrical stimulation signals: used to receive the electrical stimulation signals generated by the microcontroller 1, output two alternating current stimulation signals above kilohertz, the output mode of the electrical stimulation signals can be quickly changed, the spatial positions of the stimulation electrodes can be arbitrarily changed, and coherent wave signals are superimposed; Acquire voltage signals: used to acquire the tensile force changes generated when the muscle specimen 36 is stimulated by the phase interference electric field, convert the tensile analog signal recorded by the tensile signal acquisition module into a tensile digital signal and then input it into the microcontroller 1; The electrical signal transmission module is connected to the microcontroller 1;

[0183] The tensile signal acquisition module is used to acquire the tensile force changes generated when the muscle specimen 36 is stimulated by the phase interference electric field, and then input the tensile signal data into the electrical signal transmission module; The tensile signal acquisition module is connected to the electrical signal transmission module;

[0184] The support module is used to provide a base for fixing the present invention, fix the stimulation electrodes 6, 7, 8, 9 and the force sensors 15, the muscle specimen 36, and provide a liftable cylindrical insulating container filled with a conductive medium, and two alternating current stimulation signals above kilohertz output via the stimulation electrodes are superimposed inside the container to form a phase interference electric field;

[0185] In Embodiment 2, the microcontroller 1 used is a computer. A stimulation signal is written in the computer MATLAB software, and two alternating current signals above kHz are output. The parameters of the stimulation signal can be adjusted arbitrarily to study the phase interference electric field formed by different stimulation signals and its effect on muscle electrical stimulation;

[0186] In Embodiment 2, the electrical signal transmission module includes a USB-6361 multifunctional I / O device 2, two A395 linear stimulation isolators 3 and 4, a four-pole three-throw band switch 5, and four metal balls 6, 7, 8, and 9, where:

[0187] The USB-6361 multifunctional I / O device 2 is connected to the microcontroller 1 through a USB interface. When outputting an electrical stimulation signal, the USB-6361 multifunctional I / O device 2 converts the digital signal generated in the microcontroller 1 into an analog signal, and then transmits the electrical stimulation signal to the A395 linear stimulation isolator 3 through the output interface; when collecting the muscle tension signal, the USB-6361 multifunctional I / O device 2 converts the tension analog signal recorded by the signal transmitter 14 into a digital signal and then inputs it into the microcontroller 1;

[0188] The two A395 linear stimulation isolators 3 and 4 are used to output a constant stimulation current. There are two A395 linear stimulation isolators in total: the input interface of the first A395 linear stimulation isolator 3 is connected to the first pair of output interfaces of the USB-6361 multifunctional I / O device 2, and the output interface (two output interfaces, one positive and one negative, are the A+ and A- ports) is connected to two of the incoming wire ports of the four-pole three-throw band switch 5; the input interface of the second A395 linear stimulation isolator 4 is connected to the second pair of output interfaces of the USB-6361 multifunctional I / O device 2, and the output interface (two output interfaces, one positive and one negative, are the B+ and B- ports) is connected to the other two incoming wire ports of the four-pole three-throw band switch 5; by setting two A395 linear stimulation isolators, two independent alternating current signals above kHz can be output.

[0189] The four-pole three-position band switch 5 is used to quickly change the output form of two alternating current signals above kHz, and the direction of the phase interference electric field vector formed by superposition in space changes. The four inlets of the four-pole three-position band switch 5 are connected to the A+ and A- ports of the first A395 linear stimulation isolator 3 and the B+ and B- ports of the second A395 linear stimulation isolator 4. The four outlets of the four-pole three-position band switch 5 are connected to four metal balls (E1, E2, E3, E4) 6, 7, 8, and 9. There are a total of 3 wiring methods. By rotating the knob of the four-pole three-position band switch 5 to the first / second / third gear, the two electrical signals output from the two A395 linear stimulation isolators 3 and 4 are transmitted to the corresponding metal balls according to the preset 3 wiring methods respectively. Specifically: (1) The A+ port is connected to E1, the A- port is connected to E2, the B+ port is connected to E3, and the B- port is connected to E4, that is, an electrical signal is output on the metal balls (E1, E2) 6 and 7, and another electrical signal is output on the metal balls (E3, E4) 8 and 9; (2) The A+ port is connected to E1, the A- port is connected to E3, the B+ port is connected to E2, and the B- port is connected to E4, that is, an electrical signal is output on the metal balls (E1, E3) 6 and 8, and another electrical signal is output on the metal balls (E2, E4) 7 and 9; (3) The A+ port is connected to E1, the A- port is connected to E4, the B+ port is connected to E3, and the B- port is connected to E2, that is, an electrical signal is output on the metal balls (E1, E4) 6 and 9, and another electrical signal is output on the metal balls (E3, E2) 8 and 7.

[0190] The four metal balls (E1, E2, E3, E4) 6, 7, 8, and 9 serve as stimulation electrodes and are connected to the four outlets of the four-pole three-position band switch 5. During the test, they are placed inside a container filled with a conductive medium to output two alternating current signals above kHz and then superpose to form a phase interference electric field.

[0191] In Embodiment 2, the tensile force signal acquisition module includes a signal transmitter 14 and a force sensor 15, where:

[0192] The left side of the signal transmitter 14 is connected to the positive and negative power supplies and the A / D in the USB-6361 multifunctional I / O device 2, and the right side is connected to the force sensor 1 . The signal transmitter 14 amplifies the output signal of the force sensor 15 and then converts it into an electrical signal recognizable by the microcontroller 1 through the A / D in the USB-6361 multifunctional I / O device 2.

[0193] The tail ends of the force sensor 15 are respectively connected to the positive and negative poles of the power supply and the signal transmitter 14. One end of the force sensor 15 is fixed under the sensor-one-dimensional platform fixing plane of the I-shaped fixing rod 24 with a supporting screw. A nut is used to separate the force sensor 15 from the sensor-one-dimensional platform fixing plane to prevent the influence on the tensile signal acquisition due to the contact between the sensor and the fixing plane. There is a ring-shaped hook at the lower end of the head of the force sensor 15, which is vertically suspended. A muscle can be hung on the ring-shaped hook of the force sensor 15 with a cotton thread or a thread made of other materials to record the tensile force change of the muscle during the electrical stimulation process.

[0194] In Embodiment 2, the support module includes a first support rod 16, a second support rod 17, a third support rod 18, a fourth support rod 19, a first three-dimensional displacement platform 20, a second three-dimensional displacement platform 21, a third three-dimensional displacement platform 22, and a fourth three-dimensional displacement platform 23, where:

[0195] The four support rods 16, 17, 18, and 19 have the same structure and are all fixed on the work surfaces of the corresponding four three-dimensional displacement platforms 20, 21, 22, and 23 through the threaded holes on the fixing plane; the end planes of the Z-shaped bodies of the four support rods 16, 17, 18, and 19 are in the vertical direction, and there are several arc-shaped extensions on the planes, forming a ring-shaped structure slightly smaller than the diameter of the metal ball. The four metal balls 6, 7, 8, and 9 are respectively fitted and fixed in the ring-shaped structures of the corresponding four support rods 16, 17, 18, and 19;

[0196] The four three-dimensional displacement platforms 20, 21, 22, and 23 have the same structure and can be precisely moved within a large range on the X, Y, and Z axes of space. There is an adjustment handle on each of the three moving axes. By sequentially rotating the adjustment handles on the X, Y, and Z axes, the three-dimensional displacement platform can be moved along the slide rails on the X, Y, and Z axes respectively, so as to move within a large space range.

[0197] The first support rod 16 is fixed to the first three-dimensional displacement platform 20, and the metal ball 6 is fixed to the first support rod 16.

[0198] The second support rod 17 is fixed to the second three-dimensional displacement platform 21, and the metal ball 7 is fixed to the second support rod 17;

[0199] The third support rod 18 is fixed to the third three-dimensional displacement platform 22, and the metal ball 8 is fixed to the third support rod 18;

[0200] The fourth support rod 19 is fixed to the fourth three-dimensional displacement platform 23, and the metal ball 9 is fixed to the fourth support rod 19.

[0201] ]>By adjusting the adjustment handles of the three-dimensional displacement platform, the support rod can be finely moved in space, so that the spatial position of the metal ball can be arbitrarily adjusted.

[0202] In Embodiment 2, the support module further includes a Type-I fixing rod 24, a Type-II fixing rod 25, a one-dimensional moving platform 28, and a fifth three-dimensional displacement platform 29, where:

[0203] The Type-I fixing rod 24 has two mutually perpendicular three-dimensional platform-rod fixing planes and a sensor-one-dimensional platform fixing plane. The Type-I fixing rod 24 is fixed on the workbench surface of the fifth three-dimensional displacement platform 29 through the threaded holes on the three-dimensional platform-rod fixing plane. One end of the force measuring sensor 15 is fixed below the sensor-one-dimensional platform fixing plane with a matching screw, and the one-dimensional moving platform 28 is fixed on the side of the sensor-one-dimensional platform fixing plane with a matching screw.

[0204] The Type-II fixing rod 25 consists of a fixing plane and an L-shaped main body at the lower end. The L-shaped main body extends vertically downward, and a small horizontal plane extends from its bottom end. There is a small hole in the central area at the end of the horizontal plane. The center point of this small hole is vertically aligned with the center point of the annular hook at the lower end of the head of the force measuring sensor 15. One end of the muscle specimen 36 can be fixed in this small hole with a cotton thread or a thread made of other materials to record the change in the pulling force of the muscle during the electrical stimulation.

[0205] The one-dimensional moving platform 28 has a fixing plane, a lifting plane, and an adjusting handle. The one-dimensional moving platform 28 is vertically fixed to the sensor-one-dimensional platform fixing plane of the Type-I fixing rod 24 through the fixing plane, and the one-dimensional moving platform 28 is vertically fixed to the fixing plane of the Type-II fixing rod 25 through the lifting plane, and the three form an integral body. By rotating the adjusting handle of the one-dimensional moving platform 28, the lifting plane of the one-dimensional moving platform 28 can move in the vertical direction, while the fixing plane of the one-dimensional moving platform 28 remains stable. Then the Type-II fixing rod 25 can be lifted and lowered in the vertical direction, and the Type-I fixing rod 24 remains stable, thereby changing the vertical distance between the Type-II fixing rod 25 and the force measuring sensor 15 fixed to the Type-I fixing rod 24. Since one end of the muscle specimen 36 is fixed to the vertical annular hook of the force measuring sensor 15 and the other end is fixed to the small hole at the end of the horizontal plane at the bottom end of the Type-II fixing rod 25, when the adjusting handle of the one-dimensional moving platform 28 is rotated, the tightness of both ends of the muscle specimen 36 changes accordingly: the smaller the vertical distance between the Type-II fixing rod 25 and the force measuring sensor 15, the looser the connection between both ends of the muscle specimen 36; the larger the vertical distance between the Type-II fixing rod 25 and the force measuring sensor 15, the tighter the connection between both ends of the muscle specimen 36, and the muscle specimen 36 is stretched, thereby adjusting the pre-tension of the muscle 36 before electrical stimulation.

[0206] A liquid conductive medium is placed inside a cylindrical container, and its conductivity is similar to that of a muscle specimen. The concentration of cells and electrolytes in muscle tissue is relatively high, resulting in a relatively high conductivity, approximately 0.5 - 1.5 S / m. In this embodiment, a single isolated frog gastrocnemius muscle is used as the muscle specimen, so Ringer's solution is selected as the liquid conductive medium and can nourish the muscle specimen. During the experiment, the conductivity of Ringer's solution is measured in real time. The concentration of NaCl in Ringer's solution is increased or decreased within a small range so that the conductivity of the adjusted Ringer's solution is more than 80% of the conductivity of the muscle specimen. Generally, a conductivity of the liquid conductive medium that is 80 - 120% of the conductivity of the muscle specimen is acceptable.

[0207] The type-I fixing rod 24, type-II fixing rod 25 and the fifth three-dimensional displacement platform 29 are used in combination to fix the force sensor 15, muscle specimen 36 and one-dimensional moving platform 28, and can adjust the pre-tension before muscle electrical stimulation and record the change in the pulling force of the muscle during electrical stimulation. The type-I fixing rod 24 and type-II fixing rod 25 are combined and fixed on the same three-dimensional displacement platform 29, and it is a composite test bracket used in combination.

[0208] In Embodiment 2, the support module further includes an optical plate 32, a bottom rod 33, a lifting platform 34, and a cylindrical container 35, where:

[0209] The optical plate 32 is divided into an upper plate and a lower plate, and both are evenly covered with threaded fixing holes. The central area of the upper plate is hollowed out, and a circle is reserved around it; the lower plate is complete, and the four bottom corners of the lower plate are supported by pads.

[0210] The upper and lower rod surfaces of the bottom rod 33 have threaded fixing holes. Four bottom rods 33 are fixed to the four bottom corners of the upper and lower plates of the optical plate 32 with screws, so that the upper and lower plates of the optical plate 32 and the four bottom rods 33 are fixed as a whole to form a base structure and are stably placed on the workbench. By adjusting the knob at the center of the bottom rod 33, the length of the bottom rod can be adjusted, thereby adjusting the height difference between the upper and lower optical plates.

[0211] The lifting platform 34 includes a handwheel, a high-precision scale and a workbench surface. By manually adjusting the handwheel with reference to the high-precision scale, the height of the workbench surface of the lifting platform 34 can be finely changed;

[0212] The cylindrical container 35 is hollow inside and has no lid, and is fixed on the workbench surface of the lifting platform 34, and the two form an integral body to form a liftable test container. By adjusting the handwheel of the lifting platform 34, the longitudinal height of the cylindrical container 35 can be quickly changed. During the measurement, the inside of the cylindrical container 35 is filled with a conductive medium.

[0213] The first three-dimensional displacement platform 20, the second three-dimensional displacement platform 21, the third three-dimensional displacement platform 22, and the fourth three-dimensional displacement platform 23 are installed at the four diagonal corners of the upper plate of the optical plate 32; the fifth three-dimensional displacement platform 29 is installed on one side edge of the upper plate of the optical plate 32; the lifting table 34 is installed on the lower plate of the optical plate 32; the base provides a fixed position for the above structure.

[0214] During the experiment of muscle electrostimulation contraction, the microcontroller 1 outputs two alternating current stimulation signals above kHz to the electrical signal transmission module, and receives the muscle tension changes recorded by the tension signal acquisition module. By adjusting the adjustment handle of the three-dimensional displacement platform, the spatial positions of the metal balls 6, 7, 8, 9, and the muscle specimen 36 can be arbitrarily changed. Then, by adjusting the handwheel of the lifting table 34, the cylindrical container 35 filled with the conductive medium is raised, and the metal balls 6, 7, 8, 9, and the muscle specimen 36 are completely immersed inside the cylindrical container 35, forming a phase interference electric field inside the container, and studying the electrostimulation effect of the phase interference electric field with different vector directions on the muscle.

[0215] The above embodiments are only used to illustrate the present invention. All deformations, modifications, and applications made by those familiar with this technology within the spirit of the present invention should fall within the scope of the present invention.

Claims

1. A deep muscle electrical stimulation experiment system capable of measuring electric field distribution, the electrical stimulation experiment system comprising a microcontroller, an electrical signal transmission module, a voltage signal acquisition module, a tensile force signal acquisition module, and a support module, characterized in that the electrical signal transmission module is used for outputting electrical stimulation signals and acquiring voltage and muscle tensile force signals. The electrical signal transmission module includes an input / output device, a linear stimulation isolator, a four-pole triple-throw band switch, and a metal ball. The input / output device includes an output D / A module and an input A / D module. The D / A module is used for the mutual conversion between digital signals and analog signals, and the A / D module is used for the mutual conversion between analog signals and digital signals. The output D / A module of the input / output device is respectively connected to the microcontroller and the linear stimulation isolator. The four-pole triple-throw band switch is respectively connected to the linear stimulation isolator and the metal ball. The metal ball is used for outputting electrical stimulation signals. The voltage signal acquisition module includes three pairs of test electrodes, and the electrodes are used for measuring the three-dimensional electric field distribution of the phase interference electric field. The voltage signal acquisition module is connected to the input A / D module, and transmits the acquired voltage analog signal to the electrical signal transmission module. The input A / D module converts the voltage analog signal into a digital signal and transmits it to the microcontroller. The tensile force signal acquisition module is used for acquiring muscle tensile force signals, and transmits the acquired tensile force analog signal data to the input A / D module to be converted into a digital signal and transmitted to the microcontroller. The support module includes a lifting device, a plurality of support rods, a variety of fixing rods, and a plurality of three-dimensional displacement devices. The three-dimensional displacement devices are used for fixing the support rods and the fixing rods. The metal ball is fixed at the bottom end of the support rod. The three-dimensional displacement devices can adjust the metal ball to move in any direction in space. The lifting device includes a lifting platform and a liftable insulating container. The three-dimensional displacement devices and the lifting device are respectively detachably fixed on the support module.

2. The experimental system for electrically stimulating muscles according to claim 1, characterized in that, The insulating container is filled with a liquid conductive medium. There are two linear stimulation isolators, which respectively output two-way kilohertz sinusoidal alternating current signals through the metal balls to generate a phase interference electric field by superposition in the liquid conductive medium of the insulating container, and generate phase interference electric fields with different vector directions through different position states of the four-pole triple-throw band switch. The metal ball is completely immersed in the conductive medium of the insulating container.

3. The experimental system for electrically stimulating muscles according to claim 2, characterized in that, The tensile force signal acquisition module includes a force sensor and a signal transmitter. The head of the force sensor has a vertical annular hook for hanging muscles and measuring muscle tensile force data. The signal transmitter is used for amplifying the output signal of the force sensor. The signal transmitter is respectively connected to the force sensor and the A / D module of the input / output device.

4. The experimental system for electrically stimulating muscles according to claim 3, wherein, The voltage signal acquisition module further includes a signal amplifier. The test electrodes respectively acquire the voltage signals of two points in the XYZ directions at a certain point of the phase interference electric field at any point in space. The signal amplifier is respectively connected to the test electrodes and the A / D module of the input / output device, and is used for amplifying the voltage analog signal and outputting a voltage digital signal.

5. The experimental system for electrically stimulating muscles according to any one of claims 1-4, characterized in that, A composite test bracket is fixed on the three-dimensional displacement platform. The composite test bracket includes a one-dimensional displacement platform and type-I and type-II fixing rods. One side of the one-dimensional displacement platform is fixedly connected to the three-dimensional displacement platform through the type-I fixing rod. The force sensor is fixed at the end of the type-I fixing rod. The other side of the one-dimensional displacement platform is fixedly connected to the upper end of the type-II fixing rod. A muscle is fixedly hung between the vertical annular hook on the force sensor and the end of the type-II fixing rod. The pre-tension of the muscle can be adjusted by moving the one-dimensional displacement platform up and down.

6. The experimental system for electrically stimulating muscles according to any one of claims 1-4, characterized in that, The liquid conductive medium has a conductivity similar to that of the muscle to be measured.

7. The experimental system for electrically stimulating muscles according to claim 5, wherein There are more than 6 three-dimensional displacement platforms. A support rod is fixed on each of the 4 three-dimensional displacement platforms, and a metal ball is fixed at the end of each support rod. Type-III and type-IV fixing rods are respectively fixed on the 2 three-dimensional displacement platforms. Two pairs of electrode needles are fixed on the bottom surface of the type-III fixing rod for measuring the electric field distribution in the X and Y axis directions at any point in the phase interference electric field. One pair of electrode needles is fixed on the bottom surface of the type-IV fixing rod for measuring the electric field distribution in the Z axis direction at any point in the phase interference electric field.

8. The experimental system for electrically stimulating muscles according to any one of claims 1-4, characterized in that, The support module is a double-layer base. There are more than 6 three-dimensional displacement platforms. A support rod is fixed on each of the 4 three-dimensional displacement platforms, and a metal ball is fixed at the end of each support rod. Type-III and type-IV fixing rods are respectively fixed on the 2 three-dimensional displacement platforms. Two pairs of electrode needles are fixed on the bottom surface of the type-III fixing rod for measuring the electric field distribution in the X and Y axis directions at any point in the phase interference electric field. One pair of electrode needles is fixed on the bottom surface of the type-IV fixing rod for measuring the electric field distribution in the Z axis direction at any point in the phase interference electric field. The three-dimensional displacement platforms can be disassembled or installed on the base as needed.

9. The experimental system for electrically stimulating muscles according to claims 1-4, characterized in that, The support module is a double-layer base, which is divided into an upper plate, a lower plate and a bottom rod connecting and fixing the upper plate and the lower plate. The distance between the upper plate and the lower plate is adjusted by adjusting the length of the bottom rod.

10. The experimental system for electrically stimulating muscles according to claim 9, characterized in that, A plurality of threaded fixing holes are distributed on the upper plate and the lower plate. The three-dimensional displacement platforms are fixed at any position on the double-layer base through the threaded fixing holes.

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