CN218943366U - Single-channel surface electromyographic signal acquisition and processing equipment - Google Patents

Abstract

The embodiment of the utility model provides single-channel surface electromyographic signal acquisition and processing equipment, and relates to the field of surface electromyographic signal acquisition. The device comprises an electrode interface, a myoelectricity acquisition and processing unit, a main control unit, an isolation power supply unit, a communication isolation unit and a communication interface unit; the electrode interface is connected to the main control unit through the myoelectricity acquisition and processing unit, the main control unit is in communication connection with the communication isolation unit, the communication isolation unit is in communication connection with the communication interface unit, the communication interface unit is connected with the isolation power supply unit, and the isolation power supply unit is respectively connected with the myoelectricity acquisition and processing unit and the main control unit. The utility model combines hardware filtering and software filtering and introduces communication isolation, has the characteristics of excellent single-channel acquisition effect and weak software filtering decoding interference, and simultaneously reduces the interference of power supply on signal acquisition through the power supply isolation unit, thereby being suitable for being widely popularized and used in rehabilitation treatment of cerebral apoplexy patients.

Description

Single-channel surface electromyographic signal acquisition and processing equipment

Technical Field

The utility model relates to the field of surface electromyographic signal acquisition, in particular to single-channel surface electromyographic signal acquisition processing equipment.

Background

Along with the increasing aging of the modern society, the health problem is revealed, the number of people suffering from apoplexy is increased, and the demand of the society for rehabilitation therapy is increasing. Compared with normal healthy people, the brain stroke patient has very weak myoelectric signals at the hemiplegia side, and the current rehabilitation equipment is often based on multichannel design, and multichannel myoelectric signal acquisition equipment is often huge in volume, complex in operation and high in requirements on equipment operators, and can be used after auxiliary teaching is carried out by special medical staff. The multichannel electromyographic signal acquisition equipment is adopted to assist rehabilitation of a cerebral apoplexy patient, so that not only is the electromyographic signal acquisition effect poor, but also the equipment is high in use difficulty, severe in use condition and environmental limitation, and is not beneficial to rehabilitation of the cerebral apoplexy patient. Therefore, aiming at rehabilitation of cerebral apoplexy patients, there is a great need to design rehabilitation equipment suitable for acquiring cerebral apoplexy electromyographic signals. Based on the technical problems, the applicant provides a technical scheme of the application.

Disclosure of Invention

The utility model aims to provide single-channel surface electromyographic signal acquisition and processing equipment, which acquires electromyographic signals of the same target area through an electrode interface, processes the acquired surface electromyographic signals into digital electromyographic signals by a main control unit after differential amplification and high-pass filtering processing, and transmits the digital electromyographic signals to an upper computer.

In order to achieve the above object, the present utility model provides a single-channel surface electromyographic signal acquisition and processing device, including: the myoelectricity acquisition and processing unit is connected with the main control unit, the myoelectricity acquisition and processing unit and the electrode interface in sequence, and the electrode interface is connected to a pair of sampling electrodes; the electrode interface is used for receiving two first electromyographic signals acquired by the pair of sampling electrodes on the same target area and transmitting the first electromyographic signals to the electromyographic acquisition processing unit; the myoelectricity acquisition processing unit is used for carrying out differential amplification on the two first myoelectricity signals to obtain a second myoelectricity signal; the myoelectricity acquisition processing unit is also used for filtering the second myoelectricity signal and sending the filtered second myoelectricity signal to the main control unit; the main control unit is used for carrying out analog-to-digital conversion on the second electromyographic signal to obtain a digital electromyographic signal, and sending the digital electromyographic signal to the upper computer.

In one embodiment, the myoelectricity acquisition processing unit includes: the differential amplifying unit is connected to the electrode interface, and the high-pass filtering unit is connected to the main control unit; the differential amplification unit is used for carrying out differential amplification on the two first electromyographic signals to obtain differential amplification signals; the high-pass filtering unit is used for filtering and amplifying the differential amplification signal to obtain the second electromyographic signal.

In one embodiment, the high-pass filtering unit is further provided with a voltage follower; the voltage follower is used for providing a reference voltage signal for the high-pass filtering unit and the differential amplifying unit.

In one embodiment, the surface electromyographic signal acquisition processing device further comprises: the isolation transformer module, the linear voltage stabilizer and the LC filter are connected in sequence; the isolation voltage transformation module is connected to a power supply, the linear voltage stabilizer is also connected to the main control unit, and the LC filter is also connected to the myoelectricity acquisition and processing module; the isolation transformation module is used for carrying out power supply isolation on the input power supply voltage and outputting the power supply voltage to the linear voltage stabilizer; the linear voltage stabilizer is used for stabilizing the input direct-current voltage and outputting a voltage signal of a preset voltage to supply power for the main control unit; the LC filter is used for supplying power to the myoelectricity acquisition processing unit after filtering the voltage signal of the preset voltage.

In one embodiment, the isolation transformer module comprises: the power management chip is connected to a power supply, and the rectifying unit is connected to the linear voltage stabilizer.

In one embodiment, the differential amplifying unit includes: an instrumentation amplifier and a first resistor;

the forward input pin and the reverse input pin of the instrument amplifier are respectively connected to the two first electromyographic signals, and the output end of the instrument amplifier is connected to the high-pass filtering unit; the first resistor is connected in parallel between a first bias pin and a second bias pin of the instrumentation amplifier.

In one embodiment, the high-pass filtering unit includes: an operational amplifier, a second resistor and a third resistor; the first input end of the operational amplifier is connected to the differential amplification unit, the second input end of the operational amplifier is used for receiving a reference voltage signal, the first output end of the operational amplifier is connected to the main control unit, and the operational amplifier outputs the differential amplification signal through the first output end; the second input end of the operational amplifier receives a voltage signal of a target voltage value through the second resistor, the second input end of the operational amplifier is grounded through the third resistor, the second input end of the operational amplifier is used for receiving a reference voltage signal, and the second output end of the operational amplifier is used for outputting the reference voltage signal.

In one embodiment, the surface electromyographic signal acquisition processing device further comprises: the communication interface and the communication isolation module is connected between the main control unit and the communication interface; the communication isolation module includes: a signal isolation chip and two paths of static protection circuits; the signal isolation chip is connected to the main control unit, and the signal isolation chip is connected to the communication interface through two paths of the static protection circuits.

In one embodiment, the main control unit is configured to perform band-pass filtering on the second myoelectric signal through a band-pass filter after filtering the interference signal in the second myoelectric signal by using a power frequency filter, and then perform moving average filtering on the second myoelectric signal.

In one embodiment, the filtering frequency of the power frequency filter is 50Hz, and the filtering frequency of the band-pass filter is 10 to 400Hz.

Drawings

FIG. 1 is a schematic diagram of a single-channel surface electromyographic signal acquisition and processing device according to the utility model;

fig. 2 is a schematic connection diagram of a differential amplifying unit of a single-channel surface electromyographic signal acquisition and processing device in the utility model;

fig. 3 is a schematic connection diagram of a high-pass filter unit of a single-channel surface electromyographic signal acquisition and processing device in the utility model.

Detailed Description

The following detailed description of various embodiments of the present utility model will be provided in connection with the accompanying drawings to provide a clearer understanding of the objects, features and advantages of the present utility model. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the utility model, but rather are merely illustrative of the true spirit of the utility model.

In the following description, for the purposes of explanation of various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that an embodiment may be practiced without one or more of the specific details. In other instances, well-known devices, structures, and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" will be understood to be open-ended, meaning of inclusion, i.e. to be interpreted to mean "including, but not limited to.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "or/and" unless the context clearly dictates otherwise.

In the following description, for the purposes of clarity of presentation of the structure and manner of operation of the present utility model, the description will be made with the aid of directional terms, but such terms as "forward," "rearward," "left," "right," "outward," "inner," "outward," "inward," "upper," "lower," etc. are to be construed as convenience, and are not to be limiting.

As shown in fig. 1, a single-channel surface electromyographic signal acquisition and processing device includes: the myoelectricity acquisition and processing unit 2, the main control unit 3, the communication isolation module 4, the communication interface 5, the main control unit 3, the myoelectricity acquisition and processing unit 2 and the electrode interface 1 are sequentially connected, the electrode interface 1 is connected to a pair of sampling electrodes, the communication interface 5 is connected to the upper computer 7, and the communication isolation module 4 is connected between the main control unit 3 and the communication interface 5.

The electrode interface 1 is configured to receive two first myoelectric signals acquired by the pair of sampling electrodes on the same target area, and transmit the first myoelectric signals to the myoelectric acquisition processing unit 2. The pair of sampling electrodes can adopt the existing medical electrode sheet, the existing medical electrode sheet is installed on the electrode interface 1 in a button mode, and when in use, the sampling electrodes are adhered to the same target area of skin, so that two first electromyographic signals are obtained. Because cerebral apoplexy patient generally only need carry out two kinds of actions of making a fist and stretching out the palm of suffering side, need take precedence when using to the motion characteristic of cerebral apoplexy patient, paste the sampling electrode on patient's wrist department skin, form the electromyographic signal collection of single passageway, avoided the interference of multichannel multiple signal.

The myoelectricity acquisition and processing unit 2 comprises a differential amplification unit 21 and a high-pass filtering unit 20 which are connected with each other, wherein the differential amplification unit 21 is connected to the electrode interface 1, and the high-pass filtering unit 20 is connected to the main control unit 3. The differential amplifying unit 21 is configured to perform differential amplification on the two first myoelectric signals, so as to obtain differential amplified signals. The high-pass filtering unit 20 is configured to filter and amplify the differential amplified signal to obtain the second electromyographic signal. The high-pass filtering unit 20 is further provided with a voltage follower, and the voltage follower is used for providing a reference voltage signal for the high-pass filtering unit 20 and the differential amplifying unit 21.

In one example, the differential amplifying unit 21 includes an instrumentation amplifier and a first resistor. The forward input pin and the reverse input pin of the instrumentation amplifier are respectively connected to the two first electromyographic signals, and the output end of the instrumentation amplifier is connected to the high-pass filtering unit 20; the first resistor is connected in parallel between a first bias pin and a second bias pin of the instrumentation amplifier. As shown in fig. 2, the instrumentation amplifier uses an TI-specific instrumentation amplifier chip INA826AIDGKR, which has the characteristics of wide signal acquisition range, low noise and low power consumption, and amplifies the acquired surface electromyographic signals 50 times. the-IN pin and the +IN pin of the chip are respectively connected with two paths of differential signal wires and the-VS pin ground wire of the chip to form differential amplification acquisition of surface electromyographic signals. The first bias pin RG_1 pin and the second bias pin RG_2 pin of the chip are connected in parallel with a first resistor R7, and the resistance value of R7 is 1 Kohm. The REF pin of the chip is connected to a reference voltage signal and the VOUT pin of the chip outputs a surface electromyographic signal (shown as SINGLESAMPLE in fig. 2) that is amplified by the first signal.

In one example, the high-pass filter unit 20 includes an operational amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, and a second capacitor. The first input terminal of the operational amplifier is connected to the differential amplifying unit 21, and the first capacitor C11 (with a capacitance value of 10 nf) and the fourth resistor R4 (with a resistance value of 1k ohm) form an LC filter to perform filtering, the fourth resistor R4 and the fifth resistor R2 (with a resistance value of 50k ohm) perform signal amplification, and the second capacitor C7 (with a capacitance value of 6.8 nf) performs signal filtering. The second input end of the operational amplifier is used for receiving a reference voltage signal, the first output end of the operational amplifier is connected to the main control unit 3, and the operational amplifier outputs the differential amplified signal through the first output end. The second input end of the operational amplifier receives a voltage signal with a target voltage value through the second resistor R5 (the resistance value is 10k ohms), the second input end of the operational amplifier is grounded through the third resistor R6 (the resistance value is 10k ohms), the second input end of the operational amplifier is used for receiving a reference voltage signal, and the second output end of the operational amplifier is used for outputting the reference voltage signal. As shown in fig. 3, the operational amplifier adopts a precise operational amplifier chip AD8607ARZ-REEL, the right side of the precise operational amplifier chip AD8607ARZ-REEL is designed as a first channel, and is an active high-pass filter with an inverting operational amplifier function, a-INA pin of the chip is sequentially connected with a resistor R4 and a capacitor C11 and then connected with a VOUT pin of a TI-specific instrumentation amplifier chip INA826AIDGKR, and receives a surface electromyographic signal amplified by the first signal (shown in SINGLESAMPLE in fig. 3), the resistance value of R4 is 1k ohms, and the capacitance value of C11 is 10uf. The OUTA pin of the chip is connected with the-INA pin of the chip through a resistor R2, the resistance value of R2 is 50k ohms, a capacitor C7 is connected with the resistor R2 in parallel, the capacitance value of C7 is 6.8nf, the OUTA pin of the chip outputs the myoelectricity amplified signal (shown as SINGLEADC in fig. 3) obtained after high-pass filtering and secondary signal amplification, and the myoelectricity amplified signal is sent to the main control unit 3. The second channel on the left side of the TI special instrument amplifier chip INA826AIDGKR is designed as a voltage follower, the +INB pin of the chip is connected with a 3.3V direct current power supply through a resistor R5 and is grounded through a resistor R6, the resistance value of R5 is 10k ohms, and the resistance value of R6 is 10k ohms. The +V pin of the chip is connected with a 3.3V direct current power supply and grounded through a capacitor C10, and the capacitance value of the capacitor C10 is 100nf. the-INB pin and the OUTB pin of the chip are connected and then output the reference voltage signal. The +INA pin on the right side of the precise operational amplifier chip AD8607ARZ-REEL and the REF pin of the TI special instrument amplifier chip INA826AIDGKR are connected with the reference voltage signal. The reference voltage signal is half of a 3.3V direct current power supply, namely 1.75V, so that negative voltage signals are prevented from being generated, and signal filtering and amplification are facilitated.

The main control unit 3 performs analog-to-digital conversion on the second electromyographic signal, after receiving the second electromyographic signal from the high-pass filtering unit 20, filters the interference signal in the second electromyographic signal by using a power frequency filter, performs band-pass filtering on the second electromyographic signal by using a band-pass filter, and then performs moving average filtering on the second electromyographic signal. The filtering frequency of the power frequency filter is 50Hz, and the filtering frequency range of the band-pass filter is 10-400 Hz. In this embodiment, the main control unit 3 uses an STM32 series single-chip microcomputer to perform analog-to-digital conversion on the second electromyographic signal, and then performs sliding windowing processing, where the window length is set to 256ms, the step length is set to 128ms, and the sampling frequency is set to 1KHZ. The power frequency filter, the band-pass filter and the moving average filter are all performed in a software filtering mode, a 50HZ wave trap is adopted to filter power frequency interference signals, the band-pass filter is adopted to take out digital electromyographic signals with the frequency in the range of 10 to 400HZ, the moving average filter is adopted, after the moving average filter, the main control unit 3 performs signal decoding on the second electromyographic signals, the signal decoding result is compared with a preset decoding threshold value, and if the signal decoding result is in the decoding threshold value range, the signal decoding result is output. The surface electromyographic signals are processed by adopting a mode of combining hardware filtering and software filtering, so that the surface electromyographic signals are high in anti-interference capability in the acquisition and processing processes, stable and good surface electromyographic signals can be obtained, and the method is suitable for being widely popularized and used in rehabilitation treatment of cerebral apoplexy patients.

The communication interface 5 is used for sending the digital electromyographic signals to the upper computer 7 and supplying power for the surface electromyographic signal acquisition and processing equipment. In this embodiment, the communication interface 5 is a Type-C interface, and the surface electromyographic signal acquisition processing device communicates with the main control unit 3 through the Type-C interface. The communication isolation module 4 connected between the main control unit 3 and the communication interface 5 includes: a signal isolation chip and two paths of static protection circuits; the signal isolation chip is connected to the main control unit 3, and the signal isolation chip is connected to the communication interface 5 through two paths of the static protection circuits. The signal isolation chip adopts an ISO7221BDR chip to avoid unnecessary interference brought by signal wires, and the communication input end and the communication output end of the signal isolation chip are respectively connected with a TPD1E10B06DPYR chip to provide two paths of signal wire ESD protection, so that the anti-interference effect is further improved.

As shown in fig. 1, the surface electromyographic signal acquisition and processing device further includes: an isolation transformer module 6, a linear voltage stabilizer 63 and an LC filter 64 connected in sequence; the isolation transformer module 6 is connected to a power supply, the linear voltage stabilizer 63 is also connected to the main control unit 3, and the LC filter 64 is also connected to the myoelectricity acquisition and processing module 2; the isolation transformation module 6 is configured to perform power supply isolation on an input power supply voltage and output the power supply voltage to the linear voltage stabilizer 63; the linear voltage stabilizer 63 is configured to stabilize an input dc voltage and output a voltage signal of a preset voltage to power the main control unit 3; the LC filter 64 is configured to filter the voltage signal of the preset voltage and then supply power to the myoelectricity acquisition processing unit 2. The isolation transformer module 6 includes: the power management chip 61 is connected to a power supply, the isolation transformer 61 and the rectifying unit 62 are sequentially connected, and the rectifying unit 62 is connected to the linear voltage regulator 63. In this embodiment, the Type-C interface is used to supply power, the preset voltage is 3.3V, the rectifying unit 62 uses a rectifying diode, the LC filter 64 includes an inductor and at least one capacitor, and the inductor uses a 3.3UH inductor.

The utility model can be applied to rehabilitation training of cerebral apoplexy patients, when in use, the electrode interface 1 is installed in a button mode, so that the electrode plate is pasted on the skin, the single-channel surface electromyographic signal acquisition and processing equipment is connected with external equipment through a TYPE-C interface, and the electromyographic signals after acquisition and processing are sent to the upper computer 7 or other external equipment. In one example, the myoelectricity acquisition and processing unit 2 further includes a power supply indicator and a function indicator, where the power supply indicator is used for displaying the power supply condition of the device, the function indicator is used for displaying the myoelectricity acquisition condition of the device, when the surface myoelectricity acquisition and processing device with the single channel is correctly worn and connected as required, the power supply indicator lights up, when the myoelectricity acquisition and processing is being performed, the function indicator lights up, and when the function indicator lights off, the myoelectricity acquisition and processing is ended. The utility model combines hardware filtering and software filtering and introduces communication isolation, has the characteristics of excellent single-channel acquisition effect and weak software filtering decoding interference, simultaneously reduces the interference of power supply on signal acquisition through the power supply isolation unit 6, and is suitable for being widely popularized and used in rehabilitation treatment of cerebral apoplexy patients.

While the preferred embodiments of the present utility model have been described in detail above, it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above detailed description. In general, in the claims, the terms used should not be construed to be limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.

Claims (10)

1. A single-channel surface electromyographic signal acquisition and processing device is characterized by comprising: the myoelectricity acquisition and processing unit is connected with the main control unit, the myoelectricity acquisition and processing unit and the electrode interface in sequence, and the electrode interface is connected to a pair of sampling electrodes;

the electrode interface is used for receiving two first electromyographic signals acquired by the pair of sampling electrodes on the same target area and transmitting the first electromyographic signals to the electromyographic acquisition processing unit;

the myoelectricity acquisition processing unit is used for carrying out differential amplification on the two first myoelectricity signals to obtain a second myoelectricity signal;

the myoelectricity acquisition processing unit is also used for filtering the second myoelectricity signal and sending the filtered second myoelectricity signal to the main control unit;

the main control unit is used for carrying out analog-to-digital conversion on the second electromyographic signal to obtain a digital electromyographic signal, and sending the digital electromyographic signal to the upper computer.

2. The single-channel surface electromyographic signal acquisition and processing device of claim 1, wherein the electromyographic acquisition and processing unit comprises: the differential amplifying unit is connected to the electrode interface, and the high-pass filtering unit is connected to the main control unit;

the differential amplification unit is used for carrying out differential amplification on the two first electromyographic signals to obtain differential amplification signals;

the high-pass filtering unit is used for filtering and amplifying the differential amplification signal to obtain the second electromyographic signal.

3. The single-channel surface electromyographic signal acquisition and processing device according to claim 2, wherein the high-pass filtering unit is further provided with a voltage follower;

the voltage follower is used for providing a reference voltage signal for the high-pass filtering unit and the differential amplifying unit.

4. The single-channel surface electromyographic signal acquisition and processing device of claim 1, further comprising: the isolation transformer module, the linear voltage stabilizer and the LC filter are connected in sequence; the isolation voltage transformation module is connected to a power supply, the linear voltage stabilizer is also connected to the main control unit, and the LC filter is also connected to the myoelectricity acquisition processing unit;

the isolation transformation module is used for carrying out power supply isolation on the input power supply voltage and outputting the power supply voltage to the linear voltage stabilizer;

the linear voltage stabilizer is used for stabilizing the input direct-current voltage and outputting a voltage signal of a preset voltage to supply power for the main control unit;

the LC filter is used for supplying power to the myoelectricity acquisition processing unit after filtering the voltage signal of the preset voltage.

5. The single channel surface electromyographic signal acquisition processing device of claim 4, wherein the isolation transformation module comprises: the power management chip is connected to a power supply, and the rectifying unit is connected to the linear voltage stabilizer.

6. The single-channel surface electromyographic signal acquisition processing device of claim 2, wherein the differential amplification unit comprises: an instrumentation amplifier and a first resistor;

the forward input pin and the reverse input pin of the instrument amplifier are respectively connected to the two first electromyographic signals, and the output end of the instrument amplifier is connected to the high-pass filtering unit;

the first resistor is connected in parallel between a first bias pin and a second bias pin of the instrumentation amplifier.

7. The single-channel surface electromyographic signal acquisition processing device of claim 3, wherein the high-pass filtering unit comprises: an operational amplifier, a second resistor and a third resistor;

the first input end of the operational amplifier is connected to the differential amplification unit, the second input end of the operational amplifier is used for receiving a reference voltage signal, the first output end of the operational amplifier is connected to the main control unit, and the operational amplifier outputs the differential amplification signal through the first output end;

the second input end of the operational amplifier receives a voltage signal of a target voltage value through the second resistor, the second input end of the operational amplifier is grounded through the third resistor, the second input end of the operational amplifier is used for receiving a reference voltage signal, and the second output end of the operational amplifier is used for outputting the reference voltage signal.

8. The single-channel surface electromyographic signal acquisition and processing device of claim 1, further comprising: the communication interface and the communication isolation module is connected between the main control unit and the communication interface;

the communication isolation module includes: a signal isolation chip and two paths of static protection circuits; the signal isolation chip is connected to the main control unit, and the signal isolation chip is connected to the communication interface through two paths of the static protection circuits.

9. The single-channel surface electromyographic signal acquisition and processing device according to claim 1, wherein the main control unit is configured to perform bandpass filtering on the second electromyographic signal through a bandpass filter after filtering an interference signal in the second electromyographic signal by using a power frequency filter, and then perform moving average filtering on the second electromyographic signal.

10. The single-channel surface electromyographic signal acquisition and processing device according to claim 9, wherein the filtering frequency of the power frequency filter is 50Hz, and the filtering frequency of the band-pass filter is 10 to 400Hz.

Images