Photoelectrode for synchronously collecting bio-electricity signals and hemodynamic signals

Abstract

The invention discloses a photoelectrode for synchronously collecting bioelectricity signals and hemodynamic signals, which comprises a three-pole concentric ring electrode, a first signal conditioning circuit matched with the three-pole concentric ring electrode, a hemodynamic collection module, a main control module, a Bluetooth transmission module and a power supply module, wherein the three-pole concentric ring electrode is used for collecting a skin differential bio-electricity signal; the haemodynamics acquisition module is used for acquiring haemodynamics signals; the main control module is used for controlling the collection process of the three-pole concentric ring electrode and the hemodynamic collection module, preprocessing the bio-electricity signal and transmitting the bio-electricity signal and the hemodynamic signal outwards through the Bluetooth transmission module; the power supply module is used for supplying power.

Description

Technical Field

[0001] The present invention relates to the field of physiological signal acquisition, and in particular to an optical electrode for synchronously acquiring bioelectric signals and hemodynamic signals. Background Art

[0002] The synchronous acquisition of bioelectric signals (EEG), electromyography (EMG) and functional near-infrared spectroscopy (fNIRS) has important application value in the detection of physiological activities. EEG reflects the electrophysiological changes of neuronal activity in real time by recording electrical signals on the scalp. Electromyography (EMG) reflects the functional state of muscles by measuring the current of muscles on the surface of the body. Functional near-infrared spectroscopy (fNIRS) irradiates the human body with near-infrared light to measure the concentration changes of oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) in the blood, reflecting the blood oxygen dynamics of tissues. Based on the property of hemoglobin absorbing light of different wavelengths, fNIRS can indirectly infer the state of brain activity by detecting the intensity changes of reflected light. The synchronous acquisition of EEG or EMG and fNIRS can provide dual information: EEG or EMG has extremely high sensitivity in temporal resolution, while fNIRS can provide good spatial resolution, especially in the monitoring of blood oxygen dynamics in deep brain areas. Therefore, EEG / EMG-fNIRS fusion technology can more comprehensively reveal the dynamic relationship between bioelectric signal activity and blood oxygen changes, and provide rich multimodal information for understanding complex brain functions such as attention, memory and emotional regulation, as well as the activities of other human tissues. This method has broad application prospects in the fields of cognitive neuroscience, neurological disease diagnosis, brain-computer interface and tissue functional status assessment.

[0003] The spatial resolution of traditional bioelectric signals (EEG) is low, mainly due to the physical limitations of signal conduction. EEG records the electrical activity of the brain through electrodes on the surface of the scalp, but the signal will be weakened when passing through the meninges, skull and scalp, and diffuse during conduction, resulting in a blurred original spatial distribution; this process is called the volume conductor effect. In addition, the number of EEG electrodes is limited, usually placed on the scalp in a 10-20 system, and the sampling density is insufficient to accurately capture the subtle activities of all brain regions. Therefore, although EEG has extremely high temporal resolution, it is still difficult to compete with technologies such as fMRI or MEG in terms of spatial positioning. Traditional electromyography (EMG) acquisition is also generally low in spatial resolution. This is mainly because traditional surface electromyography electrodes are placed on the surface of the skin, making it difficult to distinguish signals from specific muscle fibers or small-scale muscle activity, especially when the electrodes cover a large skin area, the signals of different muscles or muscle fiber groups will be mixed together. In addition, surface electromyography signals are also affected by the skin, electrode spacing and volume conductor effects, making it difficult to accurately separate the activities of adjacent tissues. Summary of the invention

[0004] To achieve the above-mentioned purpose and other related purposes, the present invention discloses an optical electrode for synchronously collecting bioelectric signals and hemodynamic signals, comprising: a three-pole concentric ring electrode, a first signal conditioning circuit matched with the three-pole concentric ring electrode, a hemodynamic acquisition module, a main control module, a Bluetooth transmission module and a power supply module, wherein: The three-pole concentric ring electrode is used to collect differential bioelectric signals on the skin surface of the measured tissue; The hemodynamic acquisition module is used to acquire hemodynamic signals; The main control module is used to control the acquisition process of the three-pole concentric ring electrode and the hemodynamic acquisition module, pre-process the bioelectric signal, and transmit the bioelectric signal and hemodynamic signal to the outside through the Bluetooth transmission module; The power supply module is used for supplying power.

[0005] Furthermore, the hemodynamic acquisition module includes a multi-wavelength light source, a control and drive circuit matching the light source, a photodetector, and a second signal conditioning circuit matching the photodetector, wherein: The multi-wavelength light source is used to send photons of two different wavelengths to the tissue under test, and changes the on-off timing according to the control signal of the control and drive circuit matched with the light source; The photodetector is used to collect photons emitted from the skin of the measured tissue after being scattered by the human body to form fNIRS signals.

[0006] Furthermore, the three-pole concentric ring electrode, the first signal conditioning circuit matching the three-pole concentric ring electrode, the hemodynamic acquisition module, the main control module, the Bluetooth transmission module and the power supply module are all integrated on an FPC flexible circuit board for fitting the tissue to be measured, wherein the three-pole concentric ring electrode, the multi-wavelength light source and the photodetector are integrated on one side of the FPC flexible circuit board that fits the tissue to be measured.

[0007] Furthermore, the three-pole concentric ring electrode includes an electrode sheet base, an insulating ring, an inner ring electrode sheet, a middle ring electrode sheet, an outer ring electrode sheet and an electrode needle. The electrode sheet base is fixed on the FPC flexible circuit board. The inner ring electrode sheet, the middle ring electrode sheet and the outer ring electrode sheet are arranged from the inside to the outside with the center of the electrode sheet base as the center of the circle, and the distances between the inner ring electrode sheet, the middle ring electrode sheet and the outer ring electrode sheet are the same. The insulating rings are respectively arranged between the inner ring electrode sheet and the middle ring electrode sheet and between the outer ring electrode sheet and the middle ring electrode sheet. A number of electrode needles are arranged, and the electrode needles are arranged on the inner ring electrode sheet, the middle ring electrode sheet and the outer ring electrode sheet.

[0008] Furthermore, the three-pole concentric ring electrode also includes a sleeve, the electrode needle is inserted into the sleeve, the other end of the sleeve is fixedly connected to the surface of the corresponding electrode sheet, a spring is arranged in the sleeve, one end of the spring is fixedly connected and electrically connected to the electrode needle, and the other end of the spring is fixedly connected and electrically connected to the corresponding electrode sheet.

[0009] Furthermore, a voltage follower is connected between the electrode sheet base and the FPC flexible circuit board.

[0010] Furthermore, it also includes a host computer, which is provided with an optical impedance detection module; the optical electrode establishes a communication connection with the host computer via a Bluetooth module, and the working process of the optical electrode includes: When the optical impedance detection module detects that the optical impedance value is lower than the optical impedance threshold, it starts collecting data; The three-pole concentric ring electrodes collect differential bioelectric signals on the skin surface of the measured tissue; The multi-wavelength light source sends photons of two different wavelengths to the tissue being tested, and changes the on-off timing according to the control signal of the control and drive circuit matched with the light source; The photodetector collects photons emitted from the skin of the tissue being tested after being scattered by the human body; The first signal conditioning circuit processes the skin differential bioelectric signals collected by the three-pole concentric ring electrodes and inputs them into the main control module; The second signal conditioning circuit processes the signal collected by the photoelectric detector and inputs it to the main control module; The main control module transmits the signals of the first signal conditioning circuit and the second signal conditioning circuit to the host computer through the Bluetooth module.

[0011] Furthermore, the FPC flexible circuit board is provided with an end line row which can be connected to other photoelectrodes.

[0012] Furthermore, the entire surface of the photoelectrode is filled with polydimethylsiloxane.

[0013] Furthermore, the host computer is also used for: The Laplace potential is obtained based on the signal collected by the three-pole concentric ring electrode, including: ; Where V1 is the average potential collected by the outer ring electrode, V2 is the average potential collected by the middle ring electrode, V3 is the average potential collected by the inner ring electrode, and r is the distance between the three concentric rings; The fNIRS signals collected by the photodetector are converted into hemodynamic-related parameters using the modified Lambert-Beer law.

[0014] By adopting the above technical solution, multimodal biological signals can be collected for detection in the fields of EEG, EMG, ECG, tissue activity, tissue hemodynamics, etc. By introducing three-pole concentric ring electrodes, high spatial resolution bioelectric signal collection can be achieved. The three-pole concentric ring electrodes are used simultaneously with fNIRS technology to accurately locate the area where physiological activities occur, collect more accurate multimodal biological signals, and improve the accuracy of tissue functional status signal analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, among which:

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 A partial enlarged schematic diagram of part A.

[0017] Figure numerals: 1. flexible circuit board; 2. multi-wavelength light source; 3. photodetector; 4. three-pole concentric ring electrode; 41. electrode sheet base; 42. insulating ring; 43. inner ring electrode sheet; 44. middle ring electrode sheet; 45. outer ring electrode sheet; 46. electrode needle; 47. sleeve; 5. end wire row. DETAILED DESCRIPTION

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

[0019] Reference Figure 1 The embodiment of the present invention provides an optical electrode for synchronously collecting bioelectric signals and hemodynamic signals, comprising: The three-pole concentric ring electrode 4, the first signal conditioning circuit matched with the three-pole concentric ring electrode 4, the hemodynamic acquisition module, the main control module, the Bluetooth transmission module and the power supply module, wherein: The three-pole concentric ring electrode 4 is used to collect differential bioelectric signals on the skin surface of the measured tissue; The hemodynamic acquisition module is used to collect fNIRS signals related to hemodynamics; The main control module is used to control the acquisition process of the three-pole concentric ring electrode 4 and the hemodynamic acquisition module, pre-process the bioelectric signal, and transmit the bioelectric signal and the hemodynamic signal to the outside through the Bluetooth transmission module; The power supply module is used for supplying power.

[0020] As mentioned above, the entire surface of the photoelectrode is filled with polydimethylsiloxane to increase its softness and make it biocompatible.

[0021] By adopting the above technical solution, multimodal biological signals can be collected for detection in the fields of EEG, EMG, ECG, tissue activity, tissue hemodynamics, etc. By introducing the three-pole concentric ring electrode 4, high spatial resolution bioelectric signal collection is achieved. The three-pole concentric ring electrode 4 is used simultaneously with the fNIRS technology to accurately locate the area where physiological activities occur, collect more accurate multimodal biological signals, and improve the accuracy of tissue functional status signal analysis.

[0022] The hemodynamic acquisition module includes a multi-wavelength light source 2, a control and drive circuit matched with the light source, a photodetector 3, and a second signal conditioning circuit matched with the photodetector. The multi-wavelength light source 2 and the photodetector are connected to the FPC flexible circuit board 1 through a universal ball head mechanism, which is used to change the angle and extension distance between the multi-wavelength light source 2 and the photodetector to adapt to the curvature of the head and closely fit the head skin; wherein: The multi-wavelength light source 2 is used to send photons of two different wavelengths to the tissue under test, and change the on-off timing according to the control signal of the control and drive circuit matched with the light source; The photodetector 3 is used to collect photons emitted from the skin of the measured tissue after being scattered by the human body to form fNIRS signals.

[0023] Reference Figure 1 The three-pole concentric ring electrode 4, the first signal conditioning circuit matched with the three-pole concentric ring electrode 4, the hemodynamic acquisition module, the main control module, the Bluetooth transmission module and the power supply module are all integrated on the FPC flexible circuit board 1 for fitting the measured tissue, wherein the three-pole concentric ring electrode 4, the multi-wavelength light source 2 and the photodetector 3 are integrated on the side of the FPC flexible circuit board 1 fitting the measured tissue, and the FPC flexible circuit board 1 is provided with an end line row 5 which can be connected to other photoelectrodes, which can be multiplexed to increase the number of acquisition channels.

[0024] Reference Figure 2The three-pole concentric ring electrode 4 includes an electrode sheet base 41, an insulating ring 42, an inner ring electrode sheet 43, a middle ring electrode sheet 44, an outer ring electrode sheet 45 and an electrode needle 46. The electrode sheet base 41 is fixed on the FPC flexible circuit board 1, and the inner ring electrode sheet 43, the middle ring electrode sheet 44 and the outer ring electrode sheet 45 are arranged from the inside to the outside with the center of the electrode sheet base 41 as the center of the circle, and the distances between the inner ring electrode sheet 43, the middle ring electrode sheet 44 and the outer ring electrode sheet 45 are the same. The insulating ring 42 is respectively arranged between the inner ring electrode sheet 43 and the middle ring electrode sheet 44. A plurality of electrode needles 46 are provided between the electrode pieces 44 and between the outer ring electrode piece 45 and the middle ring electrode piece 44. The electrode needles 46 are provided on the inner ring electrode piece 43, the middle ring electrode piece 44 and the outer ring electrode piece 45. A sleeve 47 is provided on the three-pole concentric ring electrode 4. The electrode needle 46 is inserted into the sleeve 47. The other end of the sleeve 47 is fixedly connected to the surface of the corresponding electrode piece. A spring is provided in the sleeve 47. One end of the spring is fixedly connected and electrically connected to the electrode needle 46. The other end of the spring is fixedly connected and electrically connected to the corresponding electrode piece.

[0025] The electrode needle 46, the spring and the sleeve 47 cooperate with each other and can adaptively adjust the length according to the curvature of the measured tissue to closely fit the measured tissue skin.

[0026] The three-pole concentric ring electrode 4 has a high spatial resolution. Thanks to its multi-ring structure design, the electrode can perform differential measurements on electrical signals in different radial regions, thereby enhancing the sensitivity to local signals. This design enables the electrode to mainly record local signals close to the electrode, suppressing interference from distant signals; at the same time, the three-pole concentric structure can capture subtle radial potential changes and achieve accurate positioning of local signals. In addition, the differential signal acquisition method of each pair of concentric ring electrodes can effectively avoid signal interference in deep and adjacent areas, thereby significantly improving the spatial resolution.

[0027] The three-pole concentric ring electrode 4 and its first signal conditioning circuit are used to collect local bioelectric signals with high spatial resolution, especially shallow electrical activity signals near the surface of the measured tissue. Through the concentric inner ring, middle ring and outer ring, radial differential measurement can be performed, which can more sensitively detect the potential changes near the surface of the measured tissue, while suppressing the interference of electrical signals in distant or deep areas. The electrode is connected to the first signal conditioning circuit, which includes a buffer circuit, a filter circuit, and an amplifier circuit. The collected bioelectric signal is amplified and filtered, and then transmitted to the main control module, which transmits and sends it through the Bluetooth module.

[0028] A voltage follower is connected between the electrode sheet base 41 and the FPC flexible circuit board 1 .

[0029] Since the impedance of the skin-electrode interface of the metal electrode is very large, a voltage follower is introduced in this embodiment to provide ultra-high input impedance to ensure signal quality.

[0030] The multi-wavelength light source 2 and the photodetector 3 are respectively located on both sides of the FPC flexible circuit board 1 , the distance between the multi-wavelength light source 2 and the photodetector 3 is 2.5-3.5 cm, and the three-pole concentric ring electrode 4 is located at the midpoint of the line connecting the multi-wavelength light source 2 and the photodetector 3 .

[0031] The main control module controls the on and off timing of the light source and the collection timing of the detector. The light source emits two photons of different wavelengths into the human body. After multiple scattering, they are emitted from the skin surface and received by the photodetector. After receiving the escaped photons, the photodetector undergoes photoelectric conversion, amplification, and filtering, and then transmits them to the main control module and is transmitted to the outside world via Bluetooth.

[0032] It also includes a host computer, which is provided with an optical impedance detection module; the optical electrode establishes a communication connection with the host computer through a Bluetooth module.

[0033] In addition, the host computer is also used to receive signals transmitted by Bluetooth, process bioelectric signals and light intensity signals, and set parameters such as the sampling rate of the device, the arrangement order of multiple modules, and channel multiplexing.

[0034] The working process of the photoelectrode includes: When the optical impedance detection module detects that the optical impedance value is lower than the optical impedance threshold, it starts collecting data; The three-pole concentric ring electrode 4 collects the differential bioelectrical signal of the skin on the surface of the tissue being tested; The multi-wavelength light source 2 sends photons of two different wavelengths to the tissue under test, and changes the on-off timing according to the control signal of the control and drive circuit matched with the light source; The photodetector collects photons emitted by the skin of the measured tissue after being scattered by the human body, forming fNIRS signals; The first signal conditioning circuit processes the differential bioelectrical signal of the skin on the surface of the tissue to be tested collected by the three-pole concentric ring electrode 4 and inputs it to the main control module; The second signal conditioning circuit processes the signal collected by the photoelectric detector and inputs it to the main control module; The main control module transmits the signals of the first signal conditioning circuit and the second signal conditioning circuit to the host computer through the Bluetooth module.

[0035] The host computer is also used to obtain the Laplace potential according to the signal collected by the three-pole concentric ring electrode 4, including: In this embodiment, the fNIRS signal collected by the photodetector 3 is converted into hemodynamic related parameters by modifying the Lambert-Beer law, and the differential bioelectric signal collected by the three-pole concentric ring electrode 4 is calculated by the "nine-point method" to calculate the Laplace potential of the skin surface of the measured point: ; Wherein V1 is the average potential collected by the outer ring electrode sheet 45, V2 is the average potential collected by the middle ring electrode sheet 44, V3 is the average potential collected by the inner ring electrode sheet 43, and r is the distance between the three concentric rings.

[0036] In this embodiment, the electrical signal intensity converted from the optical signal received by the photodetector 3 is greater than or equal to 200mV, which is considered to be valid data. The host computer is provided with an optical impedance detection module. When the displayed optical impedance value is lower than the threshold, the collection can be started. The optical impedance value is presented as the inverse of the electrical signal intensity, and the threshold is 1 / 200.

[0037] When testing in this embodiment, firstly, a bandage is used to wrap or an elastic cloth cap to fix the relative position of the photoelectrode and the tissue to be tested, and the installation position and posture of the photoelectrode are adjusted so that the electrode, light source, and photodetector are close to the skin surface, and the optical impedance detection module of the host computer is observed. If the optical impedance value is within an acceptable range, the start acquisition button can be clicked to perform the signal acquisition operation. In this embodiment, the scalability of the photoelectrode is achieved by connecting two or more photoelectrodes through the end line row 5, and multiple photoelectrodes automatically identify the number of connections and the arrangement mode, and transmit them to the host computer. The host computer performs adaptive networking, automatically adjusts the light source on and off timing, and the photodetector acquisition timing, and realizes multi-channel multiplexing. Through the unique differential measurement potential method of the three-pole concentric ring electrode 4, combined with multi-wavelength photoelectric signal detection, through the Lambert-Beer law, combined with the different extinction coefficients of oxygenated hemoglobin and deoxygenated hemoglobin for 600-900nm light, the dual-modal detection of human tissue hemodynamic parameters is inferred.

[0038] The advantages of the present invention include: using a three-pole concentric ring electrode 4 to collect bioelectric signals, the three-pole concentric ring electrode 4 has high spatial resolution, low noise, enhanced shallow sensitivity and good anti-artifact performance, and its concentric multi-layer structure can accurately collect local bioelectric signals, reduce signal interference between distant and deep adjacent areas, and filter out background noise to improve the signal-to-noise ratio. The ring design also ensures stable contact between the electrode and the skin, reducing the impact of electrode drift. The scalability of the photoelectrode, multiple photoelectrodes can be connected by wiring to form a new collection network, and the photodetectors between the photoelectrodes can be reused when connected, thereby improving the utilization rate of the photodetectors and increasing the number of sampling channels. The retractable electrode, the retractable and steerable light source and the photodetector can adaptively adjust the angle and length according to the curvature of the surface of the tissue being measured to improve the fit.

[0039] Those skilled in the art will appreciate that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined.

[0040] For the method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0041] It can be known from the description of the above implementation modes that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server or a network device, etc.) to execute the methods described in the various implementation modes of the present application or certain parts of the implementation modes.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoelectrode for synchronously collecting bioelectric signals and hemodynamic signals, characterized in that: include: A three-pole concentric ring electrode (4), a first signal conditioning circuit matched with the three-pole concentric ring electrode (4), a hemodynamic acquisition module, a main control module, a Bluetooth transmission module and a power supply module, wherein: The three-pole concentric ring electrode (4) is used to collect skin differential bioelectric signals; The hemodynamic acquisition module is used to collect fNIRS signals related to hemodynamics; The main control module is used to control the acquisition process of the three-pole concentric ring electrode (4) and the hemodynamic acquisition module, pre-process the bioelectric signal, and transmit the bioelectric signal and the hemodynamic signal to the outside through the Bluetooth transmission module; The power supply module is used for supplying power.

2. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 1, characterized in that: The hemodynamic acquisition module comprises a multi-wavelength light source (2), a control and drive circuit matched with the light source, a photodetector (3) and a second signal conditioning circuit matched with the photodetector (3), wherein: The multi-wavelength light source (2) is used to send photons of two different wavelengths to the tissue under test, and change the on-off timing according to the control signal of the control and driving circuit matched with the light source; The photoelectric detector (3) is used to collect photons emitted from the skin of the tissue to be tested after being scattered by the human body.

3. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 2, characterized in that: The three-pole concentric ring electrode (4), a first signal conditioning circuit matched with the three-pole concentric ring electrode (4), a hemodynamic acquisition module, a main control module, a Bluetooth transmission module and a power supply module are all integrated on an FPC flexible circuit board (1) for adhering to the tissue to be measured, wherein the three-pole concentric ring electrode (4), a multi-wavelength light source (2) and a photodetector (3) are integrated on a side of the FPC flexible circuit board (1) adhering to the tissue to be measured.

4. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 3, characterized in that: The three-pole concentric ring electrode (4) comprises an electrode sheet base (41), an insulating ring (42), an inner ring electrode sheet (43), a middle ring electrode sheet (44), an outer ring electrode sheet (45) and an electrode needle (46); the electrode sheet base (41) is fixed on an FPC flexible circuit board (1); the inner ring electrode sheet (43), the middle ring electrode sheet (44) and the outer ring electrode sheet (45) are arranged from the inside to the outside with the center of the electrode sheet base (41) as the center of the circle, and the distances between the inner ring electrode sheet (43), the middle ring electrode sheet (44) and the outer ring electrode sheet (45) are the same; the insulating ring (42) is respectively arranged between the inner ring electrode sheet (43) and the middle ring electrode sheet (44) and between the outer ring electrode sheet (45) and the middle ring electrode sheet (44); a plurality of electrode needles (46) are arranged, and the electrode needles (46) are arranged on the inner ring electrode sheet (43), the middle ring electrode sheet (44) and the outer ring electrode sheet (45).

5. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 4, characterized in that: The three-pole concentric ring electrode (4) further comprises a sleeve (47), an electrode needle (46) is inserted into the sleeve (47), the other end of the sleeve (47) is fixedly connected to the surface of the corresponding electrode sheet, a spring is arranged in the sleeve (47), one end of the spring is fixedly connected and electrically connected to the electrode needle (46), and the other end of the spring is fixedly connected and electrically connected to the corresponding electrode sheet.

6. The photoelectrode for synchronous collection of bioelectric signals and hemodynamic signals according to claim 5, characterized in that: A voltage follower is connected between the electrode sheet base (41) and the FPC flexible circuit board (1).

7. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 3, characterized in that: It also includes a host computer, which is provided with an optical impedance detection module; the optical electrode establishes a communication connection with the host computer through a Bluetooth module, and the working process of the optical electrode includes: When the optical impedance detection module detects that the optical impedance value is lower than the optical impedance threshold, it starts collecting data; The three-pole concentric ring electrode (4) collects differential bioelectric signals on the skin surface of the measured tissue; The multi-wavelength light source (2) sends photons of two different wavelengths to the tissue under test, and changes the on-off timing according to the control signal of the control and driving circuit matched with the light source; The photodetector (3) collects photons emitted from the skin of the tissue being tested after being scattered by the human body to form fNIRS signals; The first signal conditioning circuit processes the differential bioelectrical signal on the skin surface of the measured tissue collected by the three-pole concentric ring electrode (4) and inputs the signal to the main control module; The second signal conditioning circuit processes the signal collected by the photoelectric detector (3) and inputs the processed signal to the main control module; The main control module transmits the signals of the first signal conditioning circuit and the second signal conditioning circuit to the host computer through the Bluetooth module.

8. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 3, characterized in that: The FPC flexible circuit board (1) is provided with an end line row (5) which can be connected to other photoelectrodes.

9. The photoelectrode for synchronous acquisition of bioelectric signals and hemodynamic signals according to claim 1, characterized in that: The entire surface of the photoelectrode is filled with polydimethylsiloxane.

10. The photoelectrode for synchronous collection of bioelectric signals and hemodynamic signals according to claim 7, characterized in that: The host computer is also used for: The Laplace potential is obtained according to the signal collected by the three-pole concentric ring electrode (4), including: ； Wherein V1 is the average potential collected by the outer ring electrode sheet (45), V2 is the average potential collected by the middle ring electrode sheet (44), V3 is the average potential collected by the inner ring electrode sheet (43), and r is the distance between the three concentric rings; The fNIRS signal collected by the photodetector (3) is converted into hemodynamic related parameters by using the modified Lambert-Beer law.

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