Atomic magnetometer magnetoencephalography system based on wireless transmission and magnetoencephalography detection method

Abstract

The present invention provides an atomic magnetometer magnetoencephalography system and magnetoencephalography detection method based on wireless transmission, which relates to the field of magnetoencephalography detection technology, and includes a wearable structural member, an atomic magnetometer, an acquisition host computer, and a control module; the atomic magnetometer can form a magnetic field detection array, and the acquisition host computer can be used to store magnetoencephalography signals collected by the atomic magnetometer; the control module is electrically connected to the atomic magnetometer via a flexible printed circuit, and the control module is connected to the acquisition host computer via wireless communication. The control module of the present invention is connected to the acquisition host computer via wireless communication, and the control module does not need to be connected to the acquisition host computer by means of a wired circuit, so that the wearer will not be constrained by the circuit during the test, thereby improving the flexibility of use and solving the problem of limited movement of the person being tested. In addition, there is no need to use a wired circuit between the control module and the acquisition host computer, and there is no need to consider the specifications and cost of the wired circuit, thereby reducing the cost of the test.

Description

Technical Field

[0001] The present invention relates to the field of brain magnetoencephalography technology, and in particular to a wireless transmission-based atomic magnetometer brain magnetoencephalography system and a brain magnetoencephalography detection method. Background Art

[0002] Magnetoencephalography (MEG), a noninvasive, real-time functional imaging technique for detecting postsynaptic magnetic changes in brain neurons, has broad application value and prospects in clinical medicine and neuroscience research. MEG uses two magnetic field detection technologies: superconducting quantum interference (SQUID) and atomic magnetometer (OPM).

[0003] Among them, since SQUIDMEG works in a superconducting environment, it needs to use a dewar tank to store liquid helium and provide insulation. As a result, the entire device is very large and difficult to move, the subjects' activities are very restricted, and the experimental paradigm design is greatly restricted. In addition, due to the insulation requirements, the magnetic detection sensitive unit is far away from the scalp, and the detected brain magnetic signal is severely attenuated.

[0004] In contrast, OPMMEG operates at room temperature and has higher ultimate sensitivity, more flexible array configuration, and higher spatiotemporal resolution. It offers superior performance and application prospects compared to SQUIDMEG, and can detect EEG signals closer to the scalp, with greater sensitivity to these signals. This is particularly important in the field of neuroscience, which is interested in weak EEG signals. Furthermore, OPMMEG is smaller and more portable, making it more convenient to use in a wider variety of scanning environments. Therefore, the portability and adaptability of OPMMEG to the environment have greatly expanded the application scope of EEG detection technology, bringing more possibilities to brain science research and clinical practice.

[0005] In existing technologies, an OPMMEG system typically consists of a magnetic field shielding device, an OPM detector array, an OPM control system, a host computer, and supporting structural components. The OPM operates by laser pumping alkali metal atoms. OPM can be categorized as either magnetic modulation or non-magnetic modulation systems based on the presence of magnetic modulation. It can also be categorized as single-axis, dual-axis, or tri-axis OPM detection based on the detectable magnetic field axis. Different detection systems also require corresponding OPM control systems for precise control of these components.

[0006] Furthermore, magnetic field shielding devices are generally divided into two types: magnetic shielding barrels and magnetic shielding rooms. OPMMEGs using shielding barrels require the subject to lie on the acquisition bed first, secure the OPM detector array, and then push it to the bottom of the shielding barrel. OPMMEGs using shielding rooms require the subject to secure the detector array and then complete the MEG measurement in the shielding room while remaining still or moving slightly. Because the OPM is very sensitive to direct current (DC) residual magnetism and alternating current (AC) magnetic noise, and the OPM control system usually has residual magnetism and magnetic noise, it can only be placed outside the magnetic shielding device to prevent interference. In this case, the existing OPMMEG has the following problems:

[0007] First, for OPMMEGs using a shielded barrel, the cable connecting the OPM and the electronics system usually needs to be more than 4 meters long, which is extremely inconvenient. In addition, the cable needs to move repeatedly during each MEG experiment, so the cable needs to have low impedance, high shielding, high mechanical properties, and high stability. This increases the size of the cable, as well as the cost and design difficulty.

[0008] Second, OPMMEG using a shielded room also faces the cable problem. Because the electronic system needs to be placed outside the magnetic shield, the cable length usually needs to be more than 4 meters, and the subjects will be restrained by the cable when moving during the MEG test.

[0009] Therefore, how to improve the existing technology of OPMMEG, such as high requirements for cable specifications, cumbersome data acquisition operations, and limited paradigm design due to restricted subject activities, in order to improve the magnetoencephalography acquisition method has become a technical problem that needs to be solved urgently. Summary of the Invention

[0010] In order to solve at least one of the above-mentioned defects in the prior art, the technical problem to be solved by the embodiments of the present invention is to provide an atomic magnetometer magnetoencephalography system and a magnetoencephalography detection method based on wireless transmission, which are used to improve the data acquisition effect of magnetoencephalography.

[0011] The above-mentioned object of the present invention can be achieved by adopting the following technical solutions. The present invention provides an atomic magnetometer magnetoencephalography system based on wireless transmission, comprising:

[0012] A wearing structure provided in the magnetic shielding space;

[0013] An atomic magnetometer, disposed on the wearable structure, capable of forming a magnetic field detection array, which can be used to detect brain magnetic signals;

[0014] An acquisition host computer, which is arranged outside the magnetic shielding space and can be used to store brain magnetic signals collected by the atomic magnetometer;

[0015] A control module is provided on the wearable structure. The control module is electrically connected to the atomic magnetometer through a flexible printed circuit. The control module is connected to the acquisition host computer through wireless communication. The control module can be used to realize state control and data transmission of the atomic magnetometer upward, receive wireless control and trigger instructions from the acquisition host computer downward, and wirelessly transmit the collected brain magnetic signals to the acquisition host computer.

[0016] In a preferred embodiment of the present invention, the control module includes a main controller, a non-magnetic control circuit module, a non-magnetic acquisition circuit module, a wireless communication module, and a battery module arranged on the main controller. The main controller is electrically connected to the atomic magnetometer via the flexible printed circuit. At least one of the main controller, the non-magnetic control circuit module, the non-magnetic acquisition circuit module, the wireless communication module, the battery module, and the flexible printed circuit is non-magnetized.

[0017] In a preferred embodiment of the present invention, at least one of the non-magnetic control circuit module and the non-magnetic acquisition circuit module is non-magnetized, and the non-magnetic control circuit module and the non-magnetic acquisition circuit module are electrically connected to the main controller and connected to the atomic magnetometer through the flexible printed circuit.

[0018] In a preferred embodiment of the present invention, the main controller is non-magnetized, and includes a circuit board and electronic components arranged on the circuit board. The circuit board is printed by a non-magnetic process, and the electronic components are formed by non-magnetic materials.

[0019] In a preferred embodiment of the present invention, the main controller and / or the non-magnetic control circuit module and / or the non-magnetic acquisition circuit module can be designed in an ordinary magnetic manner, and a magnetic field shielding layer is provided to achieve the same effect as the non-magnetic design. The magnetic field shielding layer is formed by a soft magnetic material, and the soft magnetic material can play a low-frequency magnetic field shielding role for the main controller and / or the non-magnetic control circuit module and / or the non-magnetic acquisition circuit module. If the magnetic field shielding layer is provided, the residual magnetism of the magnetic field shielding layer needs to be reduced by demagnetization, and if it is taken out of the magnetic shielding space and exposed to the geomagnetic environment, it needs to be demagnetized again when working again.

[0020] In a preferred embodiment of the present invention, in addition to the battery module, the control module is configured as a chip through a non-magnetic system-level package.

[0021] In a preferred embodiment of the present invention, the battery module is non-magnetized, and the battery module includes a non-magnetic battery pack and a non-magnetic battery driving module. The non-magnetic battery pack is formed by non-magnetic lithium-ion polymer material, and the non-magnetic battery driving module includes a non-magnetic boost voltage stabilization circuit. The non-magnetic battery pack is electrically connected to the main controller through the non-magnetic boost voltage stabilization circuit.

[0022] In a preferred embodiment of the present invention, a clock synchronization module is further included. The clock synchronization module is communicatively connected to the control module and the acquisition host computer, and the clock synchronization module can be used to synchronize the clocks of the control module and the acquisition host computer. Preferably, the clock synchronization module is wirelessly connected to the control module and the acquisition host computer.

[0023] In a preferred embodiment of the present invention, the clock synchronization module is arranged outside the shielded space, and the clock synchronization module includes:

[0024] A wireless synchronizer, which is connected to the control module and the acquisition host computer via wireless communication;

[0025] A stimulation host computer is communicatively connected to the wireless synchronizer, and the stimulation host computer can be used to transmit the control signal issued by the stimulation to the wireless synchronizer triggered by the stimulation, and the clocks of the control module, the acquisition host computer and the stimulation host computer are synchronized through the wireless synchronizer.

[0026] In a preferred embodiment of the present invention, the packet sending and receiving time of the wireless communication mode is no more than 1 ms, and the heartbeat packet protocol is disabled; and / or the transmission power of the wireless communication mode is less than 0 dBm.

[0027] In a preferred embodiment of the present invention, the wireless communication method is one of the communication methods of a Bluetooth module, a Wifi module, a Lora module or a Zigbee module.

[0028] In a preferred embodiment of the present invention, the wearing structure includes a helmet and a connecting frame connected to the helmet, the atomic magnetometer is arranged on the helmet, and the control module is arranged on the connecting frame.

[0029] In a preferred embodiment of the present invention, the atomic magnetometer is any one of a non-magnetically modulated single-axis OPM detector, a magnetically modulated dual-axis OPM detector, and a magnetically modulated three-axis OPM detector.

[0030] In a preferred embodiment of the present invention, the wireless communication method uses a full-field antenna or a directional gain antenna.

[0031] In a preferred embodiment of the present invention, the distance between the control module and the atomic magnetometer is no less than 20 cm.

[0032] The present invention also provides a magnetoencephalography detection method, which uses the aforementioned atomic magnetometer magnetoencephalography system based on wireless transmission. The magnetoencephalography detection method specifically includes the following steps:

[0033] The wearable structure is arranged in the magnetic shielding space, and the wearable structure is worn on the head of the person being tested;

[0034] Controlling the atomic magnetometer through the control module to form a magnetic field detection array, and using the magnetic field detection array to measure the magnetoencephalogram data of the wearer;

[0035] The control module is used to transmit the acquired magnetoencephalogram data to the acquisition host computer via wireless communication.

[0036] In a preferred embodiment of the present invention, the wireless transmission-based atomic magnetometer magnetoencephalography system further includes a clock synchronization module, and the following steps are further included before using the magnetic field detection array to measure the magnetoencephalography data of the wearer:

[0037] The clock synchronization module is used to synchronize the clocks of the control module and the acquisition host computer.

[0038] The technical solution of the present invention has the following significant beneficial effects:

[0039] When using the wireless transmission-based atomic magnetometer magnetoencephalography system described in the present invention, the wearable structure is placed on the head of the person being measured. The atomic magnetometer generates a magnetic field detection array, which is used to measure the wearer's magnetoencephalogram (MEG). Furthermore, during use, the front end of the atomic magnetometer can be fixed to the scalp of the person being measured, which helps improve the accuracy of the MEG measured by the atomic magnetometer and achieves better results.

[0040] Furthermore, by placing the wearable structure, atomic magnetometer, and control module within a magnetically shielded space, magnetic interference from the external environment is reduced, helping to improve the atomic magnetometer's measurement accuracy. Furthermore, because the control module and the acquisition host computer are connected via wireless communication, the control module no longer requires a wired connection to the acquisition host computer, freeing the wearer from the constraints of wired circuits during testing. This significantly increases the system's flexibility and the testee's freedom of movement, resolving the limitations of conventional designs caused by the subject's restricted movement.

[0041] Furthermore, by connecting the control module and the acquisition host computer via wireless communication, there is no need for wired circuits between the control module and the acquisition host computer, and there is no need to consider the specifications and costs of wired circuits, which significantly reduces testing costs. Furthermore, since the control module and the acquisition host computer do not use wired circuits to transmit signals, it also helps reduce the magnetic noise generated by wired circuits during use, further improving the measurement accuracy of the atomic magnetometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the various components in the drawings are merely illustrative and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the various components of the present invention. Those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to specific circumstances under the guidance of the present invention.

[0044] Figure 1 This is a schematic structural diagram of the atomic magnetometer magnetoencephalography system based on wireless transmission according to the present invention;

[0045] Figure 2 This is a functional connection block diagram of the control module of the present invention;

[0046] Figure 3 The schematic diagram of the structure of a dual-light non-magnetic modulation single-axis OPM detector;

[0047] Figure 4 A schematic diagram of the structure of a dual-axis OPM detector with single optical magnetic modulation;

[0048] Figure 5 A schematic diagram of the structure of a three-axis OPM detector with dual optical and magnetic modulation;

[0049] Figure 6 A data graph for measuring an empty room using the present invention;

[0050] Figure 7 The power spectrum data of the brain magnetic signal perpendicular to the occipital lobe is collected by applying the present invention;

[0051] Figure 8 For the general Figure 7The time domain waveform of the acquired EEG signal after bandpass filtering at 7Hz-13Hz;

[0052] Figure 9 This is a structural schematic diagram of the present invention applied in a shielding cylinder;

[0053] Figure 10 The figure is a structural diagram of the present invention applied in a magnetic shielding room.

[0054] Reference numerals in the above drawings:

[0055] 100. Wearing structure; 110. Connecting frame;

[0056] 200, atomic magnetometer; 210, alkali metal atom gas cell; 220, laser; 230, magnetic compensation self-calibration modulation coil; 240, gas cell heating and temperature control module; 250, photodiode; 260, circular polarizer;

[0057] 300, collecting host computer;

[0058] 400, control module; 410, main controller; 420, wireless communication module; 430, battery module; 431, non-magnetic battery pack; 432, non-magnetic battery drive module; 440, non-magnetic control circuit module; 450, non-magnetic acquisition circuit module;

[0059] 500, wireless synchronizer;

[0060] 600, stimulate the host computer;

[0061] 700. Flexible printed circuit. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0063] Implementation Method 1

[0064] Please refer to Figure 1 and Figure 2As shown, an embodiment of the present invention provides an atomic magnetometer magnetoencephalography system based on wireless transmission, which includes a wearable structure 100, an atomic magnetometer 200, an acquisition host computer 300 and a control module 400 arranged in a magnetic shielding space; the atomic magnetometer 200 is arranged on the wearable structure 100, and the atomic magnetometer 200 can form a magnetic field detection array, which can be used to detect brain magnetic signals; the acquisition host computer 300 is arranged outside the shielding space, and the acquisition host computer 300 can It can be used to store the brain magnetic signals collected by the atomic magnetometer 200; the control module 400 is set on the wearable structure 100, the control module 400 is electrically connected to the atomic magnetometer 200 through the flexible printed circuit 700, and the control module 400 is connected to the acquisition host computer 300 through wireless communication. The control module 400 can be used to realize the state control and data transmission of the atomic magnetometer 200 upward, receive wireless control and trigger instructions from the acquisition host computer 300 downward, and wirelessly transmit the collected brain magnetic signals to the acquisition host computer 300.

[0065] In general, when using this wireless transmission-based atomic magnetometer MEG system, the wearable structure 100 is worn on the head of the person being measured. The atomic magnetometer 200 forms a magnetic field detection array, which is used to measure the wearer's MEG. Furthermore, during use, the front end of the atomic magnetometer 200 can be fixed to the person's scalp, which helps improve the accuracy of the MEG measured by the atomic magnetometer 200 and achieves better results.

[0066] Furthermore, by placing the wearable structure 100, the atomic magnetometer 200, and the control module 400 within a magnetically shielded space, magnetic interference from the external environment can be reduced, thereby helping to improve the measurement accuracy of the atomic magnetometer 200. Furthermore, because the control module 400 is connected to the acquisition host computer 300 via wireless communication, the control module 400 does not need to be connected to the acquisition host computer 300 via a wired circuit. Thus, the wearer is not constrained by the wired circuit during the test, significantly improving the flexibility of the system and the degree of freedom of the person being tested, and resolving the problem of limited paradigm design caused by the limited movement of the person being tested in the prior art.

[0067] Furthermore, by wirelessly connecting the control module 400 and the acquisition host computer 300, there is no need for wired circuits between the control module 400 and the acquisition host computer 300, and there is no need to consider the specifications and costs of wired circuits, significantly reducing testing costs. Furthermore, since the control module 400 and the acquisition host computer 300 do not use wired circuits to transmit signals, the magnetic noise generated by wired circuits during use is also reduced, further improving the measurement accuracy of the atomic magnetometer 200.

[0068] Designers can adjust the specific formation method and size of the magnetic shielding space according to usage needs. For example, the shielding space is formed by a shielding barrel or a shielding room, and no specific restrictions are made here.

[0069] The present invention utilizes a control module 400 in conjunction with a collection host computer 300, enabling the collected MEG data to be displayed in real time on the collection host computer 300 and stored remotely, similar to wired communication. Designers can determine the specific configurations of the collection host computer 300 and stimulation host computer 600 based on their specific needs, such as a computer or controller equipped with corresponding programs, and this is not a specific limitation.

[0070] Experimental research in neuroscience often requires precise recording of trigger times within experimental paradigms, requiring a trigger signal with synchronization capabilities. Existing technologies use wired transmission to effectively control signal delay and jitter, accurately marking trigger times. However, wireless communication presents pressing technical challenges in better controlling signal delay and jitter, and accurately marking trigger times.

[0071] In order to solve the above problems, an embodiment of the present invention further includes a clock synchronization module, which is communicatively connected to the control module 400 and the acquisition host computer 300. The clock synchronization module can be used to synchronize the clocks of the control module 400 and the acquisition host computer 300.

[0072] The clock synchronization module can synchronize the clocks of the control module 400 and the acquisition host computer 300, ensuring the clock synchronization between the control module 400 and the acquisition host computer 300, thereby better controlling the delay jitter problem during signal transmission and accurately marking the trigger time.

[0073] In a feasible embodiment, the clock synchronization module is arranged outside the shielded space, and the clock synchronization module includes a wireless synchronizer 500 and a stimulation host computer 600. The wireless synchronizer 500 is connected to the control module 400 and the acquisition host computer 300 through wireless communication; the stimulation host computer 600 is communicatively connected with the wireless synchronizer 500, and the stimulation host computer 600 can be used to transmit the control signal issued by the stimulation to the wireless synchronizer 500 triggered by the stimulation, and the clock of the control module 400, the acquisition host computer 300 and the stimulation host computer 600 are synchronized through the wireless synchronizer 500.

[0074] The wireless synchronizer 500 may utilize a low-latency wireless communication protocol to synchronize the magnetic field data with the stimulation trigger signal.

[0075] By arranging the clock synchronization module outside the shielded space, it is possible to prevent the magnetic noise generated by the clock synchronization module from affecting the atomic magnetometer 200 .

[0076] In another feasible embodiment, the stimulation and control circuit modules can be independently timed using high-precision synchronized clock crystals, with synchronization performed only once at the start. Specifically, the stimulation and control circuit modules are configured on the control module 400 and the acquisition host computer 300. Before use, the control module 400, the acquisition host computer 300, and the stimulation host computer 600 are synchronized once using a wireless synchronizer 500.

[0077] For example, if the deviation between crystal oscillators is 1 ppm, then the time error between the stimulus trigger signal and the magnetic field data can be guaranteed to be no more than 1 ms within 16.67 minutes without the need for a second synchronization.

[0078] In existing technologies, the emission, transmission, and reception of radio electromagnetic waves occupy a wide range of frequency bands. This includes not only electromagnetic wave variations caused by encoding rates in the MHz and GHz range, but also the response to receiving and sending packets in the frequency band of interest for EEG signals (1-100Hz). Some wireless communication methods also use a "heartbeat packet" mechanism to maintain connections between devices, all of which can interfere with OPMMEG's detection of EEG signals.

[0079] In order to solve the above problem, in an embodiment of the present invention, the packet sending and receiving time of the wireless communication mode is no more than 1 ms, and the heartbeat packet protocol is disabled.

[0080] Since the bandwidth of the atomic magnetometer 200 generally does not exceed the kHz frequency band, by modifying the communication protocol so that the timeout for sending and receiving packets is no more than 1ms, and disabling interference protocols such as heartbeat packets, the noise caused by wireless communication is adjusted to outside the effective detection signal frequency band, thereby eliminating interference with the magnetoencephalography signal acquisition in the communication protocol.

[0081] Furthermore, by making the transmission power of the wireless communication mode less than 0 dBm, the stray noise of the wireless communication signal can be reduced through power control.

[0082] Specifically, the wireless communication method is one of a Bluetooth module, a Wi-Fi module, a Lora module, or a Zigbee module. Designers can determine and modify the specific communication protocol and specific transmission power based on the communication module used, and no specific restrictions are imposed here.

[0083] Of course, in other feasible embodiments, designers may use other types of wireless communication modules 420 according to usage requirements, and no specific limitation is made here.

[0084] In an embodiment of the present invention, the wearing structure 100 includes a helmet and a connecting frame 110 connected to the helmet. The atomic magnetometer 200 is disposed on the helmet, and the control module 400 is disposed on the connecting frame 110 .

[0085] The atomic magnetometer 200 can be installed and fixed more stably through the helmet, so that the atomic magnetometer 200 can form a magnetic field detection array on the helmet. The magnetic field detection array can be used to measure brain magnetism in different areas of the wearer's brain, which helps to obtain a brain magnetograph covering the entire brain.

[0086] Preferably, the helmet can be configured as a rigid structure. This prevents deformation during use, allowing the helmet to maintain a fixed shape, thereby facilitating the stability of the atomic magnetometer 200. The specific shape and size of the helmet 1 can be determined by the designer based on usage requirements and are not specifically limited herein.

[0087] In addition, a connecting frame 110 is also connected to the helmet. By installing the control module 400 on the connecting frame 110, on the one hand, it helps to better install and fix the control module 400, and on the other hand, it helps to shorten the distance between the atomic magnetometer 200 and the control module 400, thereby reducing the length of the flexible printed circuit 700 between the atomic magnetometer 200 and the control module 400.

[0088] Furthermore, in order to prevent the control module 400 from being exposed to the outside, a protective shell can be provided on the control module 400, and the control module 400 is connected to the connecting frame 110 through the protective shell. Designers can adjust the specific structure of the connecting frame 110 according to the needs of use, and no specific limitation is made here.

[0089] Of course, in other feasible embodiments, designers can adjust the specific structure of the wearable structure 100 so that the atomic magnetometer 200 can be fixed around the heart to meet the needs of magnetocardiography measurement, and no specific limitation is made here.

[0090] In this embodiment of the present invention, the control module 400 is spaced at least 20 cm from the atomic magnetometer 200. By securing the control module 400 and the atomic magnetometer 200 at least 20 cm apart, interference from the control module 400 on the atomic magnetometer 200 is reduced. Furthermore, the control module 400 can communicate wirelessly with the acquisition host computer 300, significantly reducing the use of wired circuits and, consequently, lowering experimental costs.

[0091] In existing technologies, when OPM control circuits are placed within a shielded space, the DC residual magnetism and AC magnetic noise generated by the circuits significantly impact detection results. These noise sources are likely to increase the local noise level of the environment and introduce specific interference, severely compromising signal purity and signal-to-noise ratio, thereby affecting the quality of the collected data.

[0092] To address the above issues, in an embodiment of the present invention, the control module 400 includes a main controller 410, a wireless communication module 420 disposed on the main controller 410, a battery module 430, a non-magnetic control circuit module 440, and a non-magnetic acquisition circuit module 450. The main controller 410 is electrically connected to the atomic magnetometer 200 via a flexible printed circuit 700, and at least one of the main controller 410, the wireless communication module 420, the battery module 430, the non-magnetic control circuit module 440, and the non-magnetic acquisition circuit module 450 is in a non-magnetized configuration.

[0093] By making at least one of the main controller 410, wireless communication module 420, battery module 430, non-magnetic control circuit module 440, and non-magnetic acquisition circuit module 450 non-magnetic, the generation of magnetic noise is reduced, thereby improving the measurement quality of magnetoencephalography. Preferably, the main controller 410, wireless communication module 420, non-magnetic battery module 430, non-magnetic control circuit module 440, and non-magnetic acquisition circuit module 450 are all non-magnetic.

[0094] In an embodiment of the present invention, the main controller 410 is non-magnetized and includes a circuit board and electronic components arranged on the circuit board. The circuit board is printed by a non-magnetic process, and the electronic components are formed by non-magnetic materials.

[0095] By using non-magnetic technology to print circuit boards and using non-magnetic materials to form electronic components, the non-magnetic transformation of circuit boards and electronic components is achieved, thereby eliminating magnetic noise on the circuit boards and electronic components.

[0096] The specific preparation process is as follows: First, a printed circuit board (PCB) is prepared using a non-magnetic process; second, in the principle design of the circuit, ferromagnetic (iron, nickel, cobalt, etc.) electronic components are not used, and are replaced by components made of other materials such as ceramics, and the use of high-conductivity materials is limited; finally, solder that does not contain ferromagnetic components is used to solder the components.

[0097] Of course, designers can adjust the specific composition and structure of the circuit board and electronic components according to usage needs, and no specific restrictions are imposed here.

[0098] In an embodiment of the present invention, at least one of the non-magnetic control circuit module 440 and the non-magnetic acquisition circuit module 450 is non-magnetized. The non-magnetic control circuit module 440 and the non-magnetic acquisition circuit module 450 are electrically connected to the main controller 410 and electrically connected to the atomic magnetometer 200 via the flexible printed circuit 700. Preferably, both the non-magnetic control circuit module 440 and the non-magnetic acquisition circuit module 450 are non-magnetized.

[0099] The control module 400 can realize state control and data transmission of the atomic magnetometer 200 upward through the non-magnetic control circuit module 440, and can wirelessly transmit the collected brain magnetic signals downward to the acquisition host computer 300 through the non-magnetic acquisition circuit module 450.

[0100] Specifically, a magnetic field shielding layer is provided on the main controller 410 and / or the non-magnetic control circuit module 440 and / or the non-magnetic acquisition circuit module 450. The magnetic field shielding layer is formed by soft magnetic material. The soft magnetic material can shield the main controller 410 and / or the non-magnetic control circuit module 440 and / or the non-magnetic acquisition circuit module 450 from low-frequency magnetic fields.

[0101] Designers can determine the specific type and composition of the soft magnetic material according to usage requirements. For example, the soft magnetic material can be a soft magnetic alloy, and no specific restrictions are made here.

[0102] By demagnetizing the magnetic field shielding layer and placing it in a shielded space, the interference of residual magnetism and magnetic noise can be limited, solving the interference problem of residual magnetism and magnetic noise caused by the circuit being introduced into the magnetic shielding space.

[0103] The shielding layer is not provided on the antenna used for wireless communication. Furthermore, the soft magnetic alloy shielding that covers each circuit cannot be exposed to magnetic fields such as the Earth's magnetic field and must be demagnetized before each use.

[0104] The designer can adjust the specific location of the magnetic field shielding layer according to the use requirements, and no specific limitation is given here. Preferably, the main controller 410, the non-magnetic control circuit module 440 and the non-magnetic acquisition circuit module 450 are all provided with a magnetic field shielding layer.

[0105] In the embodiment of the present invention, except for the battery module 430, the control module 400 is configured as a chip through a system-level package. By configuring the control module 400 as a chip, the volume of the control module 400 is significantly reduced, which helps to reduce the space occupancy and the corresponding power consumption, making the entire system more lightweight. The lightweight system can be freely placed in a magnetic shielding space such as a magnetic shielding cylinder or a shielding room, such as Figure 9 and Figure 10 The embodiment shown can better meet the wearable requirements of brain magnetic detection equipment.

[0106] In existing technologies, OPMMEGs typically require power from the power grid. However, to achieve wireless and portable OPMMEGs, batteries must be integrated into the OPM control system to support independent operation. However, after high-intensity discharge, the ferromagnetic metal material inside existing batteries retains a certain degree of magnetism. This residual magnetism can cause localized magnetic field inhomogeneities in the battery, and current fluctuations within the battery can also generate magnetic noise.

[0107] In order to solve the above problems, in an embodiment of the present invention, the battery module 430 is non-magnetized, and the battery module 430 includes a non-magnetic battery pack 431 and a non-magnetic battery driving module 432. The non-magnetic battery pack 431 is formed by non-magnetic lithium-ion polymer material, and the non-magnetic battery driving module 432 includes a non-magnetic boost voltage stabilization circuit. The non-magnetic battery pack 431 is electrically connected to the main controller 410 through the non-magnetic boost voltage stabilization circuit.

[0108] By using a non-magnetic lithium-ion polymer battery for power, the device eliminates the magnetic noise generated by ferromagnetic materials such as nickel foil, which are commonly used in most current lithium-ion batteries. Since non-magnetic lithium-ion polymer batteries do not contain any ferromagnetic materials, they are more suitable for measuring weak EEG signals.

[0109] Furthermore, the non-magnetic battery pack 431 is electrically connected to the non-magnetic main controller 410 via a non-magnetic boost and voltage-stabilizing circuit. Together, these circuits provide stable power. Furthermore, the use of a non-magnetic boost and voltage-stabilizing circuit prevents variations in battery charge from introducing noise into the detected EEG signals. The non-magnetic boost and voltage-stabilizing circuit can be demagnetized using a magnetic field shielding layer. Designers can determine the specific configuration of the non-magnetic boost and voltage-stabilizing circuit based on specific needs and are not specifically limited here.

[0110] In one feasible embodiment of the present invention, the wireless communication method uses a full-field antenna. The full-field antenna can realize omnidirectional signal transmission and reception, so that the experimental paradigm reduces the directional design restrictions.

[0111] In another embodiment of the present invention, wireless communication utilizes a directional gain antenna. Directional gain antennas utilize the relative positions of components to transmit high-power communications in the gain direction, extending communication distance and minimizing interference from stray wireless communication signals on MEG detection.

[0112] In an embodiment of the present invention, the atomic magnetometer 200 is any one of a non-magnetically modulated single-axis OPM detector, a magnetically modulated dual-axis OPM detector, and a magnetically modulated three-axis OPM detector.

[0113] Specifically, such as Figure 3 、 Figure 4 and Figure 5 In the embodiment shown, the non-magnetically modulated single-axis OPM detector, the magnetically modulated dual-axis OPM detector and the magnetically modulated three-axis OPM detector are all composed of an alkali metal atom gas chamber 210, a laser 220, a magnetic compensation self-calibration modulation coil 230, a gas chamber heating and temperature control module 240, a photodiode 250 and a circular polarizer 260.

[0114] The non-magnetic modulation OPM configuration requires the pump light and detection light to overlap perpendicularly within the alkali metal atom gas chamber 210, with the magnetic field measurement direction perpendicular to the two optical paths. The magnetic modulation dual-axis measurement configuration requires the modulation magnetic field direction to be perpendicular to the pump light within the alkali metal gas chamber. The magnetic modulation tri-axis measurement configuration requires the generation of two mutually perpendicular optical paths within the alkali metal gas chamber, with the two beams optionally overlapping or non-overlapping.

[0115] In this system, the alkali metal atom gas chamber 210 within the atomic magnetometer 200 is a core component. It is heated to a certain temperature by the gas chamber heating and temperature control module 240, causing the alkali metal atoms to vaporize. The alkali metal atoms stored in the gas chamber are polarized by pump light passing through the circular polarizer 260. The magnetic compensation self-calibration modulation coil 230 is responsible for providing magnetic field modulation signals, magnetic field calibration, and compensation. Magnetic field modulation enables the measurement of multi-axis EEG signals, magnetic field calibration is responsible for calibrating the measured EEG signals to standard units, and the compensation magnetic field is responsible for further reducing the static magnetic field size of the gas chamber within the magnetically shielded environment. The photodiode 250 is responsible for converting the obtained optical signal into an electrical signal and transmitting it to the control module 400.

[0116] In this system, the control module 400 is mainly responsible for the control and information transmission of the atomic magnetometer 200. The control module 400 may include: a main controller 410, a wireless communication module 420, a non-magnetic battery pack 431, a non-magnetic battery drive module 432, a non-magnetic control circuit module 440 and a non-magnetic acquisition circuit module 450.

[0117] In this system, the non-magnetic control circuit module 440 within the control module 400 is connected to the atomic magnetometer 200 to control it. Different control circuits correspond to different types of atomic magnetometers 200. Its primary function is to generate control signals for heating, frequency stabilization, atomic number density locking, magnetic field modulation, calibration, and magnetic field compensation, based on control commands transmitted from the main controller 410.

[0118] In this system, the non-magnetic acquisition circuit module 450 in the control module 400 is also connected to the atomic magnetometer 200 to receive and amplify the acquisition signal in the probe and transmit the signal to the main controller 410 .

[0119] In this system, the non-magnetic battery driving module 432 in the control module 400 is responsible for raising the voltage of the non-magnetic battery pack 431 to the voltage required by the system, and setting a voltage stabilization function module so that the power supply voltage of the control module 400 does not change with the battery power.

[0120] In this system, the wireless communication module 420 within the control module 400 is responsible for transmitting the instructions from the acquisition host computer 300 and the trigger signal from the stimulation-triggered wireless synchronizer 500 to the main controller 410, and at the same time transmitting the EEG acquisition signal of the main controller 410 to the acquisition host computer 300 in real time.

[0121] There are two ways to design the synchronization of trigger signals:

[0122] 1. After the stimulation-triggered wireless synchronizer 500 receives the stimulation trigger signal from the stimulation host computer 600, it adds the time stamp of the stimulation-triggered wireless synchronizer 500 and sends it to the acquisition host computer 300.

[0123] 2. When the stimulation-triggered wireless synchronizer 500 receives the trigger signal from the stimulation host computer 600, it sends it directly to the acquisition host computer 300 through real-time wireless communication without adding a time stamp. At the same time, the wireless communication module 420 also sends the brain magnetic data received from the main controller 410 to the acquisition host computer 300 through real-time wireless communication on different channels, and aligns the acquisition channel and the stimulation trigger channel according to the clock of the acquisition host computer 300.

[0124] In the empty room experiment, the system was placed in a magnetic field uniform area of a magnetic shielding space. No objects were placed except the system of the present invention. The empty room data was collected for 30 seconds and the power spectrum of the collected signal was displayed on Figure 6 .

[0125] In the eye-opening and eye-closing alpha wave suppression experiment, the atomic magnetometer 200 was placed in the occipital lobe of the subject, 2 cm away from the median fissure. This location was determined in advance by the wired EEG acquisition system as the channel location with the most obvious alpha wave response among the 30 channels in the occipital lobe. The experimental paradigm was that the subject followed the voice prompt to perform a block cycle experiment of 5 seconds of eyes closed and 5 seconds of eyes open, repeated 30 times. The power spectrum of the EEG signal collected perpendicular to the axis of the occipital lobe was displayed in Figure 7 , the time domain EEG signals after 7-13 Hz bandpass filtering are displayed on Figure 8 .

[0126] Based on the above innovative designs and improvements, this application realizes the portable improvement of wireless communication magnetoencephalography, solves the difficulties originally faced in wired and wireless transmission, enables it to be more widely used in fields such as psychology and medicine, and provides more comprehensive and in-depth data support for neuroscience and medical research.

[0127] In addition, the present invention carried out an empty room test and an open-eye-closed alpha wave suppression experiment to verify its feasibility and effectiveness. Figure 6 As shown in the figure, it can be seen that the sensitivity of the atomic magnetometer magnetoencephalography system based on wireless transmission in this application is about The power spectrum of the brain magnetic signal between opening and closing eyes in the alpha wave suppression experiment is as follows Figure 7 As shown in the figure, the time domain waveform of the EEG signal after 7-13Hz bandpass filtering (including α wave frequency band) is as follows: Figure 8 As shown. Figure 7 and Figure 8 It can be seen that the present invention can accurately measure the α wave suppression when a person opens his eyes and the α wave signal when he closes his eyes, and the power spectrum between open and closed eyes is significantly different in the α wave frequency band.

[0128] Implementation Method 2

[0129] An embodiment of the present invention provides a magnetoencephalography (MEG) detection method, which uses the wireless transmission-based atomic magnetometer MEG system described in Embodiment 1. The MEG detection method specifically includes the following steps:

[0130] Step 1000: placing the wearable structure 100 in a magnetic shielding space, and wearing the wearable structure 100 on the head of the person being tested;

[0131] Step 2000: Controlling the atomic magnetometer 200 through the control module 400 to form a magnetic field detection array, and using the magnetic field detection array to measure the wearer's magnetoencephalogram data;

[0132] Step 3000: Utilize the control module 400 to transmit the acquired MEG data to the acquisition host computer 300 via wireless communication.

[0133] The specific structure, working principle and beneficial effects of the atomic magnetometer magnetoencephalography system based on wireless transmission are the same as those described in the first embodiment and will not be repeated here.

[0134] This magnetoencephalography detection method utilizes the wireless transmission-based atomic magnetometer magnetoencephalography system of Example 1, allowing the control module 400 to communicate with the acquisition host computer 300 without the aid of a wired circuit, so that the wearer will not be constrained by the wired circuit during the test, significantly improving the flexibility of use and the freedom of the person being tested, and solving the limitations of the paradigm design caused by the restricted activities of the person being tested in the prior art.

[0135] Furthermore, by connecting the acquisition host computer 300 and the control module 400 via wireless communication, there is no need to use a wired circuit between the acquisition host computer 300 and the control module 400, and there is no need to consider the specifications and costs of the wired circuit, thereby significantly reducing the test cost.

[0136] In an embodiment of the present invention, the wireless transmission-based atomic magnetometer magnetoencephalography system further includes a clock synchronization module and the following steps before measuring magnetoencephalography data of the wearer using the magnetic field detection array:

[0137] Step 4000: Perform clock synchronization on the control module 400 and the acquisition host computer 300 through the clock synchronization module.

[0138] By synchronizing the clocks of the control module 400 and the acquisition host computer 300, the clock synchronization between the control module 400 and the acquisition host computer 300 is ensured, thereby better controlling the delay jitter problem during signal transmission and accurately marking the trigger time.

[0139] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "essentially consisting of..." describing a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel features of the combination. The use of the terms "comprising" or "including" to describe the combination of elements, ingredients, parts or steps herein also contemplates an embodiment that is essentially composed of these elements, ingredients, parts or steps. By using the term "may", it is intended to illustrate that any attribute described that "may" include is optional. Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0140] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An atomic magnetometer magnetoencephalography system based on wireless transmission, characterized in that: include: A wearable structure, an atomic magnetometer, and a control module are provided within the magnetic shielding space, wherein the atomic magnetometer and the control module are both provided on the wearable structure, the atomic magnetometer can form a magnetic field detection array, and the magnetic field detection array can be used to detect brain magnetic signals; the control module is electrically connected to the atomic magnetometer, and the distance between the control module and the atomic magnetometer is not less than 20 cm; The control module includes a main controller, a non-magnetic control circuit module, a non-magnetic acquisition circuit module, a wireless communication module, and a battery module arranged on the main controller. The main controller is electrically connected to the atomic magnetometer via a flexible printed circuit. At least one of the non-magnetic control circuit module, the non-magnetic acquisition circuit module, the wireless communication module, the battery module, and the flexible printed circuit is non-magnetized. The main controller is non-magnetized and includes a circuit board and electronic components arranged on the circuit board. The circuit board is printed using a non-magnetic process, and the electronic components are formed using non-magnetic materials. The preparation process of the main controller includes: preparing a printed circuit board using a non-magnetic process; not using ferromagnetic electronic components and limiting the use of high-conductivity materials; and soldering the components using solder that does not contain ferromagnetic components. The main controller and / or the non-magnetic control circuit module and / or the non-magnetic acquisition circuit module are provided with a magnetic field shielding layer, and the magnetic field shielding layer is formed of a soft magnetic material, and the soft magnetic material can shield the main controller and / or the non-magnetic control circuit module and / or the non-magnetic acquisition circuit module from the magnetic field; An acquisition host computer is arranged outside the magnetic shielding space and can be used to store brain magnetic signals collected by the atomic magnetometer; The control module is connected to the acquisition host computer via wireless communication. The packet sending and receiving time of the wireless communication method is no more than 1ms, and the heartbeat packet protocol is closed. The transmission power of the wireless communication method is less than 0dBm. The control module can be used to realize the state control and data transmission of the atomic magnetometer upward, receive wireless control and trigger instructions from the acquisition host computer downward, and wirelessly transmit the collected brain magnetic signals to the acquisition host computer.

2. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: It also includes a clock synchronization module, which is communicatively connected to the control module and the acquisition host computer, and can be used to synchronize the clocks of the control module and the acquisition host computer.

3. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 2, characterized in that: The clock synchronization module is arranged outside the shielded space, and the clock synchronization module includes: A wireless synchronizer, which is connected to the control module and the acquisition host computer via wireless communication; A stimulation host computer is communicatively connected to the wireless synchronizer, and the stimulation host computer can be used to transmit the control signal issued by the stimulation to the wireless synchronizer triggered by the stimulation, and the clocks of the control module, the acquisition host computer and the stimulation host computer are synchronized through the wireless synchronizer.

4. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: The wireless communication mode is one of the communication modes of Bluetooth module, Wifi module, Lora module or Zigbee module.

5. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: The wearing structure comprises a helmet and a connecting frame connected to the helmet, the atomic magnetometer is arranged on the helmet, and the control module is arranged on the connecting frame.

6. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: At least one of the non-magnetic control circuit module and the non-magnetic acquisition circuit module is in a non-magnetized configuration. The non-magnetic control circuit module and the non-magnetic acquisition circuit module are electrically connected to the main controller and the atomic magnetometer, respectively.

7. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: In addition to the battery module, the control module is configured as a chip through a non-magnetic system-level package.

8. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: The battery module includes a non-magnetic battery pack and a non-magnetic battery driving module. The non-magnetic battery pack is formed by non-magnetic lithium-ion polymer material. The non-magnetic battery driving module includes a non-magnetic boost voltage stabilization circuit. The non-magnetic battery pack is electrically connected to the main controller through the non-magnetic boost voltage stabilization circuit.

9. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1, characterized in that: The atomic magnetometer is any one of a non-magnetically modulated single-axis OPM detector, a magnetically modulated dual-axis OPM detector, and a magnetically modulated three-axis OPM detector.

10. The atomic magnetometer magnetoencephalography system based on wireless transmission according to claim 1 or 3, characterized in that: The wireless communication method adopts a full-field antenna or a directional gain antenna.

11. A magnetoencephalography detection method, characterized in that: Using the atomic magnetometer magnetoencephalography system based on wireless transmission according to any one of claims 1 to 10, the magnetoencephalography detection method specifically comprises the following steps: The wearing structure is arranged in the magnetic shielding space, and the wearing structure is worn on the head of the person being tested; Controlling the atomic magnetometer through the control module to form a magnetic field detection array, and using the magnetic field detection array to measure the magnetoencephalogram data of the wearer; The control module is used to transmit the acquired magnetoencephalogram data to the acquisition host computer via wireless communication.

12. The magnetoencephalography detection method according to claim 11, wherein: The wireless transmission-based atomic magnetometer magnetoencephalography system further includes a clock synchronization module and the following steps before measuring magnetoencephalography data of the wearer using the magnetic field detection array: The clock synchronization module is used to synchronize the clocks of the control module and the acquisition host computer.

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