Joint detection device for electroencephalogram and photoacoustic imaging

Abstract

The invention provides an electroencephalogram and photoacoustic imaging combined detection device, and relates to the technical field of medical information detection. The joint detection device comprises a conductive composite layer suitable for releasing conductive gel in a state of being in contact with skin; the electroencephalogram electrode is embedded in the conductive composite layer and is suitable for transmitting an electroencephalogram signal to an external signal acquisition device when the conductive composite layer is in contact with the skin; the light-induced ultrasonic transmitter is embedded in one end of the conductive composite layer and is constructed to be capable of converting light energy into ultrasonic energy so as to send out an ultrasonic signal and detect nerves and blood vessels under the skin; and the photoinduced ultrasonic receiver is embedded at the other end of the conductive composite layer and is suitable for receiving the ultrasonic signal reflected by the nerve blood vessel and obtaining the spatial information of the nerve blood vessel by using the reflected ultrasonic signal, so that the spatial information of the nerve blood vessel is associated with the electroencephalogram signal, and an electroencephalogram with a target temporal-spatial resolution is obtained.

Description

Technical Field

[0001] The present disclosure relates to the technical field of medical information detection, and in particular to a combined detection device for electroencephalogram (EEG) and photoacoustic imaging. Background Art

[0002] Electroencephalogram (EEG) detection technology captures the voltage fluctuations generated by the synchronous discharge of neuronal groups through EEG electrodes. Based on millisecond response speed, it can accurately track transient changes in synaptic potentials. It has millisecond time resolution and is suitable for monitoring the rapid dynamic processes of neural activity.

[0003] However, the attenuation and diffusion effects of the skull and soft tissue on electrical signals lead to blurred spatial localization, making it difficult to distinguish signal sources from adjacent brain regions. Single EEG detection technology has high temporal resolution but low spatial resolution. Therefore, how to effectively improve the spatial resolution of EEG is a key issue in current brain science research. Summary of the Invention

[0004] In view of this, the present disclosure provides a joint detection device for electroencephalography and photoacoustic imaging.

[0005] The combined detection device for electroencephalography and photoacoustic imaging provided by the present disclosure includes: a conductive composite layer, adapted to release a conductive gel when in contact with the skin; an electroencephalogram (EEG) electrode, embedded in the conductive composite layer, adapted to transmit EEG signals to an external signal acquisition device when the conductive composite layer is in contact with the skin; a photoultrasound transmitter, embedded in one end of the conductive composite layer, configured to convert light energy into ultrasonic energy to emit ultrasonic signals and detect nerves and blood vessels under the skin; and a photoultrasound receiver, embedded in the other end of the conductive composite layer, adapted to receive ultrasonic signals reflected back from the nerves and blood vessels, and to obtain spatial information of the nerves and blood vessels using the reflected ultrasonic signals, so as to correlate the spatial information of the nerves and blood vessels with the EEG signals and obtain an EEG with a target spatiotemporal resolution.

[0006] According to an embodiment of the present disclosure, it further includes: a pulse laser, which is adapted to send pulse laser to the photoultrasound transmitter and send a trigger signal to the electroencephalogram electrode for synchronously collecting electroencephalogram signals.

[0007] According to an embodiment of the present disclosure, the photoultrasound transmitter includes: an elastic shell, which defines a cavity; a thermal expansion material filled in the cavity, which is suitable for converting light energy into heat energy under light irradiation and causing the thermal expansion material to expand in volume to generate an ultrasonic signal.

[0008] According to an embodiment of the present disclosure, the thermal expansion material includes a polymer material of polydimethylsiloxane and nanoparticles; the nanoparticles include at least one of carbon nanotube particles, molybdenum disulfide, and gold nanoparticles.

[0009] According to an embodiment of the present disclosure, the ratio of carbon nanotube particles to polydimethylsiloxane is 1:8 to 1:9.

[0010] According to an embodiment of the present disclosure, the photo-ultrasound receiver includes a plurality of photo-ultrasound receivers, and the plurality of photo-ultrasound receivers are embedded in the conductive composite layer in an array.

[0011] According to an embodiment of the present disclosure, a photoacoustic receiver includes: a packaging shell; a single-mode optical fiber, which is arranged in the packaging shell and is suitable for transmitting input light; a hollow-core optical fiber, one end of which is connected to the output end of the single-mode optical fiber and is suitable for providing a hollow cavity; and a reflective diaphragm, which is connected to the other end of the hollow-core optical fiber and can be deformed in response to an ultrasonic signal to change the cavity length of the hollow cavity.

[0012] According to an embodiment of the present disclosure, the outer diameters of the single-mode optical fiber and the hollow-core optical fiber are consistent.

[0013] According to an embodiment of the present disclosure, the conductive composite layer includes: a base layer having an upper surface and a lower surface; a gel layer arranged on the lower surface, the gel layer being capable of releasing conductive gel when the conductive composite layer is in contact with the skin; and a base silver film arranged on the upper surface, suitable for transmitting EEG signals.

[0014] According to an embodiment of the present disclosure, the gel layer includes a porous composite material composed of silver nanoparticles and polymethylhydrogensiloxane, and polyvinyl alcohol hydrogel filled in the porous composite material.

[0015] According to the embodiments of the present disclosure, by integrating the EEG electrodes, photoultrasound transmitters and photoultrasound receivers in the composite conductive layer, the two functions of EEG signal transmission and ultrasonic detection can be realized simultaneously. After the EEG signals are collected by the EEG electrodes and the ultrasonic signals reflected by the neurovascular are collected by the ultrasonic transmitter and the ultrasonic receiver, it is convenient to obtain the hemodynamic image of the neurovascular using the ultrasonic signals reflected by the neurovascular according to the principle of photoacoustic imaging, and establish a correlation between the slight changes in blood flow velocity and the EEG signals, thereby obtaining an EEG image with high temporal and spatial resolution, and realizing the effect of improving the spatial resolution of the EEG signal by using the high spatial resolution of the ultrasonic signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0017] Figure 1 The figure schematically shows the overall structure of the combined detection device of electroencephalography and photoacoustic imaging according to an embodiment of the present disclosure;

[0018] Figure 2The structure diagram of the photo-induced ultrasound receiver according to an embodiment of the present disclosure is schematically shown;

[0019] Figure 3 The flowchart of the method for generating spatiotemporal resolution EEG images according to an embodiment of the present disclosure is schematically shown.

[0020] Reference numerals

[0021] 1. EEG electrodes;

[0022] 2. Photo-induced ultrasound transmitter;

[0023] 3. Photo-induced ultrasound receiver;

[0024] 31. Encapsulation shell;

[0025] 32. Single-mode optical fiber;

[0026] 33. Hollow core optical fiber;

[0027] 34. Reflective diaphragm;

[0028] 4. Pulsed laser;

[0029] 5. Conductive composite layer;

[0030] 51. Base silver film;

[0031] 52. basal layer;

[0032] 53. Gel layer. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0034] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0035] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0036] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art. For example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc. When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art. For example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.

[0037] It should also be noted that directional terms such as "upper," "lower," "front," "back," "left," and "right" mentioned in the embodiments are merely references to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, identical elements are represented by identical or similar reference numerals. Conventional structures or configurations will be omitted where they may cause confusion in understanding this disclosure.

[0038] Figure 1 The figure schematically shows the overall structure of the combined detection device of electroencephalography and photoacoustic imaging according to an embodiment of the present disclosure.

[0039] According to the combined detection device of electroencephalography and photoacoustic imaging provided by the present disclosure, Figure 1 As shown, the combined detection device includes a conductive composite layer 5, an electroencephalogram (EEG) electrode, a photoultrasound transmitter 2, and a photoultrasound receiver 3. The conductive composite layer 5 is adapted to release a conductive gel when in contact with the skin. The EEG electrode is embedded in the conductive composite layer 5 and adapted to transmit EEG signals to an external signal acquisition device when the conductive composite layer 5 is in contact with the skin. The photoultrasound transmitter 2 is embedded in one end of the conductive composite layer 5 and adapted to generate an ultrasonic signal under light irradiation to detect nerves and blood vessels. The photoultrasound receiver 3 is embedded in the other end of the conductive composite layer 5 and adapted to receive ultrasonic signals reflected back from the nerves and blood vessels, and to obtain spatial information of the nerves and blood vessels using the reflected ultrasonic signals, so as to correlate the spatial information of the nerves and blood vessels with the EEG signals and obtain an EEG with a target spatiotemporal resolution.

[0040] The conductive composite layer 5 can be composed of a conductive material and another base material (such as a polymer). The conductive composite layer 5 provides a good electrical conduction path and ensures that the EEG electrodes can accurately capture EEG signals. The conductive composite layer 5 has a first surface and a second surface. The first surface has a certain mechanical strength to support the electronic components. The second surface is flexible to meet skin contact requirements.

[0041] The EEG electrodes may include conductive probes embedded within the conductive composite layer 5 and EEG sensors located outside the conductive composite layer 5. When brain neurons become excited, they produce electrical potential changes, which are transmitted through the scalp to the conductive probes. The conductive probes transmit electrical signals to the EEG sensors, which can then be connected to an external signal acquisition device to transmit the EEG signals. In some embodiments, the conductive probes include, but are not limited to, silver-silver chloride probes and silver nanowire probes.

[0042] When the photoultrasound transmitter 2 receives a laser pulse of a specific wavelength, the absorbent material inside it rapidly absorbs the light energy, causing a sharp increase in the local temperature. This temperature change causes the material to expand, generating pressure waves, or ultrasound waves. These waves can penetrate brain tissue to the nerves and blood vessels, where they are reflected.

[0043] The photoacoustic receiver 3 receives the ultrasonic signal reflected from the tissue for photoacoustic imaging. Photoacoustic imaging combines the high contrast of optics with the high resolution of ultrasound to provide spatial location information of nerves and blood vessels.

[0044] Since EEG sensing has millisecond-level time resolution, by combining the spatial position information of blood vessels provided by photoacoustic imaging, an EEG with a target temporal and spatial resolution can be obtained. The EEG with a target temporal and spatial resolution has both high temporal and spatial resolution.

[0045] In some embodiments, the photoultrasound transmitter 2 and the photoultrasound receiver 3 may be disposed on both sides of the EEG electrodes.

[0046] In such an embodiment, by integrating the EEG electrodes, the photoultrasound transmitter 2 and the photoultrasound receiver 3 in the composite conductive layer, the two functions of EEG signal transmission and ultrasonic detection can be realized simultaneously. After the EEG signals are collected by the EEG electrodes and the ultrasonic signals reflected by the neurovascular are collected by the ultrasonic transmitter and the ultrasonic receiver, it is convenient to obtain the hemodynamic image of the neurovascular using the ultrasonic signals reflected by the neurovascular according to the principle of photoacoustic imaging, and establish a correlation between the slight changes in blood flow velocity and the EEG signals, thereby obtaining an EEG image with high temporal and spatial resolution, and realizing the effect of improving the spatial resolution of the EEG signal by using the high spatial resolution of the ultrasonic signal.

[0047] According to the embodiments of the present disclosure, Figure 1 As shown, the combined detection device further includes a pulse laser 4, which is adapted to send pulse lasers to the photoultrasound transmitter 2 and send trigger signals to the electroencephalogram electrodes for synchronously collecting electroencephalogram signals.

[0048] Specifically, the pulse laser 4 is connected to the ultrasonic transmitter, emitting pulsed laser light (wavelength 800-1000 nm), and causing the photoultrasonic transmitter 2 to generate 1-10 MHz ultrasonic waves. At the same time, the pulse laser 4 is also connected to the trigger input port of the EEG electrode 1. Each time the pulse laser 4 sends a pulsed laser to the photoultrasonic transmitter 2, it synchronously sends a trigger signal to the EEG electrode 1 to align the timestamps of the EEG signal and the ultrasonic signal to ensure that the time error is less than 1 ms.

[0049] In such an embodiment, by using the same pulse light source for the EEG electrode 1 and the photoultrasound transmitter 2, the compatibility problem caused by different light sources is solved, and real-time matching of optical EEG-ultrasound imaging data is achieved.

[0050] According to the embodiments of the present disclosure, Figure 1 As shown, the conductive composite layer 5 includes a base layer 52, a gel layer 53, and a base silver film 52. The base layer 52 has an upper surface and a lower surface. The gel layer 53 is disposed on the lower surface and is capable of releasing conductive gel when the conductive composite layer 5 is in contact with the skin. The base silver film 52 is disposed on the upper surface and is suitable for transmitting EEG signals.

[0051] The base layer 52 can be made of flexible polymers, including but not limited to polyimide (PI), polyethylene terephthalate (PET), and polydimethylsiloxane (PDMS). The base layer 52 serves as the support for the entire structure and can provide mechanical strength, flexibility, and adhesion to other layers.

[0052] The base silver film 52 can be a pure silver film or a silver-silver chloride (Ag / AgCl) mixed coating, which acts as a conductive layer to provide a low-resistance path for transmitting EEG signals.

[0053] The gel layer 53 includes a porous composite material composed of silver nanoparticles and polymethylhydrogensiloxane, and polyvinyl alcohol hydrogel filled in the porous composite material.

[0054] When the conductive composite layer 5 is in contact with the skin, the polyvinyl alcohol hydrogel can be slowly released to the contact interface between the conductive composite layer 5 and the skin to reduce the impedance of the contact interface and improve the conductive performance.

[0055] According to an embodiment of the present disclosure, a photoultrasound transmitter 2 includes an elastic housing and a thermal expansion material. The elastic housing defines a cavity. The thermal expansion material is filled within the cavity and is adapted to convert light energy into heat energy under illumination, causing the thermal expansion material to expand in volume, thereby generating an ultrasonic signal.

[0056] The elastic shell can be made of materials such as polydimethylsiloxane, silicone, or polyurethane. The cavity can be configured into a cylindrical, spherical, or microfluidic structure.

[0057] In some embodiments, an elastic cavity with a certain curvature and size can be designed according to the curvature and internal structure of the brain skull, so that the ultrasound transmitter can better fit the skull surface and improve the transmission efficiency of the ultrasound signal.

[0058] When a light pulse hits the surface of a light-absorbing material, the electrons in the material absorb the photon energy and jump to a higher energy level. This energy is converted into heat, causing instantaneous volume expansion. This periodic expansion-contraction cycle generates ultrasonic signals.

[0059] In some embodiments, the thermal expansion material may include carbon nanotubes, graphene foam, or metal nanoparticles.

[0060] Preferably, the thermal expansion material may be a polymer material of polydimethylsiloxane and nanoparticles, wherein the nanoparticles include at least one of carbon nanotube particles, molybdenum disulfide, and gold nanoparticles.

[0061] Carbon nanotubes have a unique electronic band structure, with energy level differences matching the energy of photons of specific wavelengths, enabling efficient photon absorption. For example, single-walled carbon nanotubes exhibit significant light absorption in the near-infrared region. This is because the energy of near-infrared photons precisely matches the energy difference required for electron transitions in carbon nanotubes. The absorbed light energy is rapidly converted into heat, which causes a localized temperature rise within the material. According to the principle of thermal expansion, the material's volume expands as the temperature rises. This expansion is a rapid mechanical motion, generating stress waves within the material. These stress waves propagate into the biological tissue being examined in the form of ultrasonic waves.

[0062] By utilizing carbon nanotube particles and highly elastic polydimethylsiloxane (PDMS) as light-absorbing particles and elastic media, and combining them with the transmission properties of the brain skull, an ultrasound transmitter can penetrate brain tissue to the greatest extent possible and reach the capillaries. The lattice vibration modes within the carbon nanotubes can effectively convert photon energy into thermal energy, generating heat more efficiently under the same light intensity. By combining them with highly elastic materials such as PDMS, the thermal expansion generated by the carbon nanotubes can better coordinate with other materials, making the thermal expansion process more uniform and effective, thereby improving the intensity and quality of ultrasound emission. When a pulsed laser is incident on the elastic cavity, a broadband, high-frequency ultrasound signal can be generated based on the photoacoustic effect. This allows thermal energy to be more efficiently converted into ultrasound energy.

[0063] In an illustrative embodiment, the photoacoustic transmitter 2 can be prepared by uniformly dispersing carbon nanotube particles in PDMS to form a composite material with excellent mechanical properties and photoacoustic effects. The mass ratio of carbon nanotubes to PDMS is 1:8 to 1:9. The method for uniformly dispersing the carbon nanotube particles in the PDMS elastic medium is as follows: Place the raw materials in a test tube. First, use a point-to-point vortex oscillator to oscillate the test tube for 40 to 60 seconds to initially disperse the carbon nanotube particles. Then, place the test tube in an ultrasonic oscillator and oscillate continuously for 7 to 8 minutes to fully disperse the carbon nanotubes. Fill the composite material into the cavity of a suitable elastic shell to produce the photoacoustic transmitter 2.

[0064] According to an embodiment of the present disclosure, the photo-ultrasound receiver 3 includes a plurality of photo-ultrasound receivers 3 , which are embedded in the conductive composite layer 5 in an array.

[0065] Specifically, the array structure of the photoultrasound receivers 3 may be arranged in a 4×4, 8×8 or custom irregular array manner to form a spatially distributed multi-channel detection system to cover the target area.

[0066] In such an embodiment, high-resolution hemodynamic images can be generated by performing image reconstruction based on ultrasound signals using the geometric position information of the ultrasound receiver array.

[0067] Figure 2 The structural diagram of the photoultrasound receiver 3 according to the embodiment of the present disclosure is schematically shown.

[0068] According to the embodiments of the present disclosure, Figure 2 As shown, the photoacoustic receiver 3 includes an encapsulating housing 31, a single-mode optical fiber 32, a hollow-core optical fiber 33, and a reflective diaphragm 34. The single-mode optical fiber 32 is disposed within the encapsulating housing 31 and is adapted to transmit input light. One end of the hollow-core optical fiber 33 is connected to the output end of the single-mode optical fiber 32, thereby forming a hollow cavity. The reflective diaphragm 34 is connected to the other end of the hollow-core optical fiber 33 and is capable of deforming in response to ultrasonic signals to change the length of the hollow cavity.

[0069] Based on the principle of optical Fabry-Perot interference, when the ultrasound reflected from the nerves and blood vessels acts on the reflective diaphragm 34 of the ultrasound receiver, the reflective diaphragm 34 deforms, causing the length of the hollow cavity to change, thereby achieving phase modulation of the light waves transmitted in the optical fiber.

[0070] Specifically, the incident light from the single-mode fiber 32 undergoes a first reflection at the end faces of the single-mode fiber 32 and the hollow-core fiber 33. The transmitted light entering the hollow-core fiber 33 is then transmitted through the hollow-core fiber 33 to the reflective diaphragm 34, where it undergoes a second reflection. After being transmitted through the hollow-core fiber 33, the transmitted light is recoupled into the single-mode fiber 32, where it interferes with the first reflected light. When the reflective diaphragm 34 deforms upon receiving the ultrasonic wave, the cavity length of the ultrasonic receiver changes, causing the intensity distribution of the interference spectrum of the two reflected lights to change. This achieves phase modulation of the transmitted light wave, converting the information of the ultrasonic signal into changes in the optical signal. The ultrasonic signal information can then be obtained by detecting the changes in the optical signal.

[0071] According to the embodiment of the present disclosure, the outer diameters of the single-mode optical fiber 32 and the hollow-core optical fiber 33 are consistent, thereby facilitating packaging of the single-mode optical fiber 32 and the hollow-core optical fiber 33 in the packaging shell 31 .

[0072] Figure 3 The flowchart of the method for generating spatiotemporal resolution EEG images according to an embodiment of the present disclosure is schematically shown.

[0073] like Figure 3 As shown, the method includes operations S310-380.

[0074] In operation S310 , EEG signals are collected using the EEG electrodes 1 .

[0075] The sampling frequency can be set to ≥1 kHz, covering the 0.5-100 Hz frequency band, ensuring that the full-band characteristics of EEG activity are captured.

[0076] In operation S320 , the photo-ultrasound receiver 3 is used to collect ultrasound signals.

[0077] A pulsed laser 4 (wavelength 800-1000 nm) excites the carbon nanotube-PDMS composite material, generating 1-10 MHz ultrasonic waves. The deformation signal of the reflective diaphragm 34 is detected by an optical fiber receiver array, and the photoacoustic effect is used to convert the light energy into ultrasonic signals.

[0078] In operation S330 , the EEG signal is pre-processed.

[0079] It can filter out low-frequency baseline drift (such as respiratory interference) and high-frequency noise (such as 50 Hz power frequency interference), as well as separate and remove biological artifacts such as eye movements and electromyography, retaining pure EEG signals.

[0080] In operation S340 , the ultrasonic signal is pre-processed.

[0081] Based on the principle of Fabry-Perot interferometry, the phase change of the optical signal is converted into the amplitude of the ultrasonic pressure wave. Using short-time Fourier transform, the characteristics of blood flow velocity variation (0.1-5 Hz) are extracted to capture the dynamics of microvascular pulsation. Based on the geometric position of the ultrasound receiver array, hemodynamic images are generated with a spatial resolution of ≤0.5 mm.

[0082] Simultaneously, the synchronous trigger signal from pulsed laser 4 aligns the timestamps of the EEG and photoacoustic data, ensuring a time error of ≤1 ms. The photoacoustic imaging vascular locations are mapped to the EEG electrode coordinate system. Combined with a standard MRI / CT brain template, the 3D coordinates of the EEG electrodes are correlated with the photoacoustic vascular locations, establishing a spatial correspondence between brain region activation and blood flow.

[0083] In operation S350 , EEG features are extracted.

[0084] Extract time domain features: Extract the amplitude and latency of event-related potentials (ERPs) to reflect the temporal response characteristics of specific brain regions. Extract frequency domain features: Calculate the power spectral density of alpha waves (8-12 Hz) and beta waves (12-30 Hz) to analyze brain function. Generate EEG spectrograms based on time domain features and frequency domain features.

[0085] In operation S360 , ultrasonic features are extracted.

[0086] Extract features such as microvascular blood flow velocity and blood volume change rate, and generate a blood flow distribution heat map.

[0087] In operation S370 , features are fused.

[0088] The EEG spectrogram (time × frequency) and photoacoustic blood flow heat map (space × time) are input into the convolutional neural network to extract spatiotemporal features (time × space × frequency band), and output EEG images with high spatiotemporal resolution. The spatial resolution can reach submillimeter spatial accuracy, thereby improving the spatial resolution of EEG.

[0089] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A combined detection device for electroencephalography and photoacoustic imaging, characterized in that: include: A conductive composite layer adapted to release the conductive gel when in contact with the skin; an electroencephalogram electrode, embedded in the conductive composite layer and adapted to transmit electroencephalogram signals to an external signal acquisition device when the conductive composite layer is in contact with the skin; a photo-ultrasound transmitter, embedded in one end of the conductive composite layer, configured to convert light energy into ultrasonic energy to emit ultrasonic signals and detect nerves and blood vessels under the skin; A photoacoustic receiver is embedded in the other end of the conductive composite layer and is suitable for receiving the ultrasonic signal reflected back from the neurovascular vessel, and using the reflected ultrasonic signal to obtain the spatial information of the neurovascular vessel, so as to associate the spatial information of the neurovascular vessel with the electroencephalogram signal and obtain an electroencephalogram with the target spatiotemporal resolution.

2. The joint detection device according to claim 1, characterized in that: Also includes: A pulse laser is adapted to send pulse laser to the photoultrasound transmitter and send a trigger signal for synchronously collecting brain electrical signals to the electroencephalogram electrodes.

3. The joint detection device according to claim 1, characterized in that: The photoultrasound transmitter comprises: an elastic shell, wherein a cavity is defined in the elastic shell; The thermal expansion material is filled in the cavity and is adapted to convert light energy into heat energy under light irradiation and cause the thermal expansion material to expand in volume, thereby generating the ultrasonic signal.

4. The joint detection device according to claim 3, characterized in that: The thermal expansion material includes a polymer material of polydimethylsiloxane and nanoparticles; The nanoparticles include at least one of carbon nanotube particles, molybdenum disulfide, and gold nanoparticles.

5. The joint detection device according to claim 4, characterized in that: The ratio of the carbon nanotube particles to the polydimethylsiloxane is 1:8 to 1:

9.

6. The joint detection device according to claim 1, characterized in that: The photo-ultrasound receivers include a plurality of photo-ultrasound receivers, which are embedded in the conductive composite layer in an array.

7. The joint detection device according to claim 1 or 5, characterized in that: The photoultrasound receiver comprises: Package shell; a single-mode optical fiber disposed in the package housing and adapted to transmit input light; A hollow-core optical fiber, one end of which is connected to the output end of the single-mode optical fiber and is suitable for providing a hollow cavity; A reflective diaphragm is connected to the other end of the hollow-core optical fiber, and the reflective diaphragm can be deformed in response to the ultrasonic signal to change the cavity length of the hollow cavity.

8. The joint detection device according to claim 7, characterized in that: The outer diameters of the single-mode optical fiber and the hollow-core optical fiber are consistent.

9. The joint detection device according to claim 1, characterized in that: The conductive composite layer comprises: a basal layer having an upper surface and a lower surface; A gel layer is provided on the lower surface, and the gel layer is capable of releasing the conductive gel when in contact with the conductive composite layer and the skin; A base silver film is arranged on the upper surface and is suitable for transmitting brain electrical signals.

10. The joint detection device according to claim 9, characterized in that: The gel layer includes a porous composite material composed of silver nanoparticles and polymethylhydrogensiloxane, and a polyvinyl alcohol hydrogel filled in the porous composite material.

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