An fnirs host for use in conjunction with an mri imaging system and fnirs system

Abstract

The application provides an fnirs host and fnirs system for use with an MRI imaging system. The fnirs host includes a communication interface and a shielded housing containing a set of APD devices, each APD device configured to be connected to a corresponding D probe on a head cap via a first optical fiber bundle, the pins or plating of each APD device employing a second non-ferromagnetic metal; a main processor and processing circuit configured to be electrically connected to the set of APD devices, employing a third non-ferromagnetic metal; and a light source portion or a driving portion, the light source portion or the driving portion operating under the control of the main processor and the processing circuit, neither of the light source portion or the driving portion containing ferromagnetic material. The fnirs host is small in size and can be placed in a scanning hole of an MRI scanning room, shortening the length of the optical fiber on the head cap worn by the subject and facilitating the adjustment of the probe on the head cap worn by the subject.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of near-infrared brain function imaging, in particular to an fnirs host for use in cooperation with an MRI imaging system and an fnirs system. BACKGROUND

[0002] The fnirs (functional near-infrared spectroscopy) device and the MRI (magnetic resonance imaging) device are two brain imaging technologies with different physical principles, and the brain information obtained by the two technologies can complement each other in many aspects, thereby providing more comprehensive diagnostic information for doctors. The combination of the MRI and fnirs modalities can more accurately diagnose and evaluate the brain function state. However, the MRI scanning room does not allow built-in ferromagnetic materials, and it is difficult to reasonably place the fnirs device in the radiology MRI scanning room.

[0003] The existing method can be seen from Figure 1 The host and the upper computer are placed outside the scanning room, for example, in the control room or workstation. At the same time, a waveguide hole is formed in the wall of the scanning room, and the optical fiber connected to the head cap worn by the subject is connected to the host outside the scanning room through the waveguide hole, and the near-infrared light emitted by the LED outside the scanning room is transmitted to the S probe (emission probe) on the head cap worn by the subject through the optical fiber passing through the wall, so as to emit near-infrared light to the head of the subject.

[0004] However, placing the host and the upper computer outside the scanning room causes the optical fiber passing through the wall to be as long as 5-10 meters, which not only causes significant light attenuation, but also is prone to breakage when being dragged due to its own weight. In addition, in the case where the subject needs to cooperate with the EEG (electroencephalogram) and PET (positron emission tomography) modalities, the subject needs to drag the optical fiber as long as 5-10 meters to first debug the probe on the head cap and the fnirs detection signal in the control room, then go to the treatment room to inject medicine while dragging the long optical fiber, and finally return to the scanning room. It is extremely inconvenient. Moreover, if the subject needs to be in the scanning room, the optical fiber corresponding to each probe needs to be removed before going to inject medicine, and after the subject returns to the scanning room, the optical fiber needs to be reinstalled for each probe, and after the installation, the probe and the fnirs detection signal still need to be debugged. Not only is the operation time long, but also the instability is high. SUMMARY

[0005] In view of the above technical problems in the prior art, the present application is proposed. The present application provides an fnirs host for use in cooperation with an MRI imaging system and an fnirs system. The fnirs host does not contain ferromagnetic materials and has a small volume, and can be placed in the scanning hole of the MRI scanning room, thereby shortening the length of the optical fiber connecting the probe on the head cap and the fnirs host, enabling the subject to move conveniently, and simplifying the steps of debugging the probe for the subject and reducing the operation time.

[0006] According to a first aspect of the present application, there is provided an fnirs host for use in cooperation with an MRI imaging system, the fnirs host being sized to be placed within a predetermined peripheral space range concentric with a scan bore of the MRI imaging system, the fnirs host comprising specifically a communication interface and a shielded housing. The communication interface is configured to be communicatively connected to a host computer in a control room in a wired manner without introducing ferromagnetic materials, to transmit fnirs detection data to the host computer. The shielded housing is made of a first non-ferromagnetic metal, and the shielded housing contains therein a set of APD devices, each APD device being configured to be connected to a corresponding D probe on a headgear via a first optical fiber bundle to receive near-infrared light emitted from a head of a subject and convert the near-infrared light into an electrical signal, and a package of each APD device being made of a non-ferromagnetic material, and a metal adopted by pins or plating of each APD device being a second non-ferromagnetic metal; a main processor and a processing circuit configured to be electrically connected to the set of APD devices to process the electrical signal to obtain fnirs detection data, wherein a metal adopted by electrical devices and electrical connection lines is a third non-ferromagnetic metal; and a light source part for transmitting near-infrared light to a corresponding S probe on the headgear via a second optical fiber bundle, or a driving part for connecting to each near-infrared LED at the corresponding S probe on the headgear via an electrical wire to make the near-infrared LED emit near-infrared light, the light source part or the driving part being operated under control of the main processor and the processing circuit, and neither the light source part nor the driving part containing ferromagnetic materials.

[0007] According to a second aspect of the present application, there is provided an fnirs system for use in cooperation with an MRI imaging system, comprising a headgear for mounting probes, an fnirs host for use in cooperation with an MRI imaging system as described in various embodiments of the present application, a control system in a machine room and a host computer in a control room, the MRI imaging system comprising a scan bore.

[0008] Compared with the prior art, the beneficial effects of the embodiments of the present application are as follows:

[0009] The fnirs host provided by the embodiments of the present application is sized to be placed within a predetermined peripheral space range concentric with a scan bore of an MRI imaging system, the shielded housing is made of a first non-ferromagnetic metal, pins or plating of APD devices in the shielded housing adopt a second non-ferromagnetic metal, electrical devices and electrical connection lines are made of a third non-ferromagnetic metal, and neither the light source part nor the driving part contains ferromagnetic materials, so that the fnirs host can be placed in the scan bore of the MRI imaging system without affecting the magnetic field environment and without causing harm to equipment and personnel.

[0010] In this embodiment, the fnirs host is placed in the scanning hole, and is communicatively connected to the host computer in the control room through the communication interface of the fnirs host in a wired manner without introducing magnetic materials. The fnirs host is connected to the probe on the head cap worn by the subject through a second optical fiber or wire, and since the fnirs host is directly placed in the scanning hole, the distance between the fnirs host and the head cap of the subject is short, and the length of the second optical fiber or wire is shortened (for example, the length of the second optical fiber or wire only needs to be 0.5 meters). In this way, the subject can conveniently move with the second optical fiber or wire and the fnirs host. Alternatively, the fnirs host can be placed in the scanning hole at all times, and the second optical fiber or wire can be removed for convenient movement, and then connected to the fnirs host after returning to the scanning room.

[0011] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented in accordance with the content of the description, and in order to make the above description and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0012] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components throughout the several views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, various embodiments discussed herein, and are not intended to limit the present disclosure to the embodiments presented in the figures. Such embodiments are illustrative and exemplary, and not intended to be exhaustive or exclusive, of the present methods, apparatus, systems, or non-transitory computer readable medium having instructions for implementing the methods.

[0013] Figure 1 A schematic diagram showing the configuration of the fnirs host used in cooperation with the MRI imaging system according to the prior art is shown.

[0014] Figure 2 A schematic diagram showing the fnirs host provided according to the embodiments of the present application for use in cooperation with the MRI imaging system placed in the scanning hole is shown.

[0015] Figure 3 A schematic diagram showing the spatial variation of the gradient magnetic field in the MRI imaging system according to the embodiments of the present application is shown.

[0016] Figure 4 A schematic diagram showing the provision of a support platform in the predetermined peripheral spatial range of the isocenter in the scanning hole for placing devices related to the electroencephalograph used in cooperation with the MRI system according to the embodiments of the present application is shown.

[0017] Figure 5 A structural diagram of an fnirs host for use in cooperation with an MRI imaging system is shown.

[0018] Figure 6 A structural diagram of a fiber bundle interface, a fiber bundle connector, a wire bundle interface, and a wire bundle connector is shown.

[0019] Figure 7 A structural diagram of a first mounting frame inside the host is shown.

[0020] Figure 8 A structural diagram of an fnirs system for use in cooperation with an MRI imaging system is shown. DETAILED DESCRIPTION

[0021] In order to make the skilled in the art better understand the technical solutions of the present application, the present application will be described in detail below in conjunction with the drawings and specific embodiments. The embodiments of the present application will be further described in detail below in conjunction with the drawings and specific embodiments, but not as a limitation to the present application.

[0022] The "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are used for the purpose of distinguishing and facilitating description, but not rigidly limited to "first" and "second". For example, "first non-ferromagnetic metal" and "second non-ferromagnetic metal" can be the same non-ferromagnetic metal, or different non-ferromagnetic metals. The "including" or "containing" and similar words used in the present application mean that the elements before the word cover the elements listed after the word, and do not exclude the possibility of also covering other elements. In the present application, the arrows shown in the figure are only an example of the execution order, but not a limitation, and the technical solutions of the present application are not limited to the execution order described in the embodiments. The steps in the execution order can be combined, decomposed, and exchanged in order, as long as the logical relationship of the execution content is not affected.

[0023] All the terms used in the present application (including technical terms or scientific terms) have the same meaning as understood by the ordinary skilled in the art to which the present application belongs, unless otherwise specifically defined. It should also be understood that the terms defined in, such as general dictionaries, should be interpreted to have meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or excessively formalized sense, unless otherwise defined explicitly herein. The technology and equipment known to the ordinary skilled in the relevant art can not be discussed in detail, but in appropriate cases, the technology and equipment should be considered as part of the specification.

[0024] In some embodiments of the present application, an fnirs host for use in cooperation with an MRI imaging system is provided, as shown in Figure 2 The fnirs host 101 is adapted to be placed within a predetermined peripheral spatial range concentric to the scan bore of the MRI imaging system.

[0025] During the MRI image acquisition process, the gradient magnetic field plays a key role in spatial positioning. By applying gradient magnetic fields in three directions (usually x-direction (transverse direction), y-direction (height direction), and z-direction (longitudinal direction)), the signal characteristics at different spatial positions are different. As shown in Figure 3 , the strength of the gradient magnetic field changes with the radial distance from the isocenter (the distance from the isocenter in the x-y cross section), and the gradient magnetic field strength is smallest at the isocenter, and the farther away from the isocenter, the more obvious the gradient magnetic field changes, and the rate of change of the magnetic field strength at the edge of the gradient coil is the largest.

[0026] Therefore, the fnirs host 101 is placed as centrally as possible within the scan bore, and the magnetic field at the position of the fnirs host 101 changes more gently, and the induced electromagnetic force and eddy current are smaller, so that the effect of the electromagnetic force on the fnirs host 101 can be reduced, and displacement or damage of the components of the fnirs host 101 due to force can be avoided, and the heat generated by the eddy current and the interference with the MRI magnetic field are also reduced, which is beneficial to ensure the normal operation of the fnirs device and the quality of the MRI image.

[0027] In some embodiments, a support platform can also be provided within the predetermined peripheral spatial range concentric to the scan bore for placing related devices such as electroencephalograph amplifiers used in cooperation with the MRI system, as shown in Figure 2 and Figure 4 The support platform is raised from the bottom of the scan bore, so that the electroencephalograph amplifiers and fnirs host 101 placed on the support platform are closer to the center of the scan bore.

[0028] The complete MRI imaging system site layout mainly includes a control room (also referred to as an operation room) in which MRI professionals operate the MRI equipment, a scanning room (also referred to as a scanning room) opposite the control room and connected thereto, that is, a place where a patient receives scanning, a machine room (storing various cabinets related to MRI, including a radio frequency transmission system, a gradient transmission system, a radio frequency receiving and reconstruction system, and a magnet refrigeration system and power supply, etc., also referred to as an equipment room) next to the scanning room. The site layout can also include a workstation (a place where a doctor views and analyzes MRI images) and a treatment room. In some cases, the workstation and the control room can be integrated. When using modalities such as EEG and PET in combination with MRI, the subject is usually given conductive glue or contrast agent in the treatment room. The fnirs host 101 specifically includes a communication interface 201, a shielded shell 202, a group of APD devices 203 contained in the shielded shell 202, a main processor and processing circuit 204, and a light source part or driving part 205, which will be described in detail below. Figure 5

[0029] As shown in Figure 5 , the communication interface 201 is configured to be communicatively connected to the host computer in the control room (also referred to as the operation room) in a wired manner without introducing ferromagnetic materials, to transmit fnirs detection data to the host computer. A hole (for example, a reserved waveguide hole) can be opened on the wall of the scanning room to pass the communication cable.

[0030] The wired manner can be a wire or an optical fiber. After the fnirs host 101 is placed in the scanning hole, the wire or optical fiber connected to the communication interface 201 is connected to the host computer in the control room through the hole in the wall. That is, the communication interface 201 is connected to the host computer in the control room via a wire or an optical fiber to transmit fnirs detection data. The wire or optical fiber for communication can be basically fixed, such as being plugged into the communication interface 201 in a pluggable manner. Once the fnirs host 101 is to be moved, the wire or optical fiber for communication can be unplugged from the communication interface 201, and then plugged into the communication interface 201 when the fnirs host 101 is back in place in the scanning hole. In this way, the wire or optical fiber for communication will not be dragged or moved, so even if it is relatively long, it will not affect the convenience of the subject's activity, nor will it affect the accuracy of the signal.

[0031] In addition, the fnirs host 101 and the host computer can also communicate through a wireless transmission manner. The wireless transmission manner includes point-to-point communication in a 5G communication mode, Wifi direct (without a router) communication mode, etc., which is not limited.

[0032] ​The shielding shell 202 is made of a first non-ferromagnetic metal, such as aluminum, copper, gold, silver, etc. In a preferred embodiment, the first non-ferromagnetic metal is aluminum, which is inexpensive and has a small density and light weight, facilitating installation and movement. The shielding shell 202 made of aluminum can effectively shield the strong magnetic field generated by the MRI imaging system and the electromagnetic waves in the surrounding environment.

[0033] In some other embodiments of the present application, the shielding shell 202 has a first size in a first dimension, a second size in a second dimension, and a third size in a third dimension, wherein the first size is smaller than the second size, and the second size is smaller than the third size.

[0034] Specifically, the first size is along the y-axis direction, the second size is along the x-axis direction, and the third size is along the z-axis direction. By setting the first size to be smaller than the second size, the shielding shell 202 has a flat cross-section in the x-y plane, facilitating stacking with other devices such as an EEG amplifier. When the fnirs host 101 is stacked with other devices, it is required to remain in the radial direction without deviating from the center. Further, by setting the second size to be smaller than the third size, the largest third size of the shielding shell 202 is along the z-axis direction (see Figure 3 ), and the rate of change of the gradient magnetic field is low over a sufficient length in the z-axis direction, so that a position with a low rate of change of the gradient magnetic field can be found along the z-axis direction to place the shielding shell 202.

[0035] Returning to the embodiments of the present application, each APD device 203 is configured to be connected to a corresponding D probe (receiving probe) on the headgear via a first optical fiber bundle to receive near-infrared light emitted from the head of the subject and convert it into an electrical signal, and the package of each APD device 203 is made of a non-ferromagnetic material, and the metal used for the pins or plating of each APD device 203 is a second non-ferromagnetic metal.

[0036] The APD device 203, i.e. Avalanche Photodiode, is provided in the fnirs host 101, and the APD device 203 is connected to the corresponding D probe on the headgear via a first optical fiber bundle. The first optical fiber bundle has good light transmission characteristics, and can efficiently transmit the near-infrared light emitted from the corresponding D probe on the headgear of the subject to the APD device 203. This connection method can ensure that the near-infrared light has less loss during transmission, and can accurately guide the near-infrared light to the corresponding APD device 203 for detection, while reducing the mutual interference between the lines exposed to the scanning hole (because it is an optical fiber bundle) and the magnetic field.

[0037] The APD device 203 converts the received near-infrared light into an electrical signal by using the internal photoelectric effect, and the electrical signal can be subsequently amplified and processed by the main processor and processing circuit 204, which is not limited.

[0038] The package of each APD device 203 is made of a non-ferromagnetic material to avoid interfering with the magnetic field strength of the MRI imaging system, affecting the imaging quality, and damaging the equipment or causing harm to the subject.

[0039] In this embodiment, the main processor and processing circuit 204 are configured to be electrically connected to a group of APD devices 203 to process the electrical signal to obtain fnirs detection data, wherein the metal used in the electrical device and the electrical connection line is a third non-ferromagnetic metal.

[0040] In some embodiments, the second non-ferromagnetic metal and the third non-ferromagnetic metal are copper. Copper has higher electrical conductivity, produces less eddy current and less heat under changing magnetic fields, and has less difference in magnetic permeability with air, which can reduce the interference with the magnetic field, eddy current effect, heat generation and signal artifacts.

[0041] Specifically, after the APD device 203 converts the received near-infrared light emitted from the subject's head into an electrical signal, the electrical signal containing physiological information related to the subject's head tissue is transmitted to the main processor and processing circuit 204 through electrical connection. However, the electrical signal can be weak and may be mixed with noise and other interference factors. The main processor and processing circuit 204 perform a series of processing operations on the received electrical signal, including amplifying the signal to increase the strength of the signal to a level that can be effectively analyzed, filtering to remove high-frequency noise or other irrelevant interference components and improve the quality of the signal, and analog-to-digital conversion to convert continuous analog electrical signals into digital signals for further analysis and processing by computers or other digital processing devices. In addition, it can also include feature extraction, data correction and other processing steps to highlight the feature information related to fnirs detection.

[0042] After a series of processing, the main processor and processing circuit 204 convert the original electrical signal into fnirs detection data, which is transmitted to the host computer in the control room through the communication interface 201 in a wired manner based on the communication interface circuit, so that the host computer can analyze the fnirs detection data to obtain blood oxygen parameters, blood flow changes and other physiological parameter-related numerical values, waveforms or images.

[0043] In this embodiment, the corresponding D probe on the headgear worn by the subject is connected to the fnirs host 101 via an optical fiber, while the corresponding S probe can be designed differently.

[0044] For example, one design is that the shielding shell 202 contains the light source part 205, wherein the light source part 205 adopts a set of near-infrared LED devices, and further includes a light source driving circuit capable of driving the near-infrared LED to emit near-infrared light. In the case that no electronic device is arranged in the corresponding S probe on the head cap worn by the subject, the light source part 205 emits near-infrared light, and the near-infrared light is transmitted to the corresponding S probe on the head cap via the second optical fiber bundle. That is, the shielding shell 202 includes the light source part 205 that transmits the near-infrared light to the corresponding S probe on the head cap via the second optical fiber bundle.

[0045] In some embodiments, the fnirs host 101 further includes an optical fiber bundle interface for detachably plugging an optical fiber bundle, wherein the optical fiber bundle includes the first optical fiber bundle and / or the second optical fiber bundle, and specifically, an end of the optical fiber bundle away from the probe is formed with an optical fiber bundle connector, and the optical fiber bundle interface is detachably plugged with the optical fiber bundle connector. The optical fiber bundle connector includes the first optical fiber bundle connector and / or the second optical fiber bundle connector. The first optical fiber bundle connector is formed by gathering the ends of the first optical fiber bundle away from the D probes, and the second optical fiber bundle connector is formed by gathering the ends of the second optical fiber bundle away from the S probes.

[0046] Exemplarily, Figure 6 The optical fiber bundle connector 601 shown can be plugged into the optical fiber bundle interface 602, which can be the first optical fiber bundle connector, the second optical fiber bundle connector, or both the first optical fiber bundle connector and the second optical fiber bundle connector. In addition, the fnirs host 101 can further include a wire bundle interface 605 for detachably plugging a wire bundle, and specifically, an end of the wire bundle away from the S probe is formed with a wire bundle connector 604, and the wire bundle interface 605 is detachably plugged with the wire bundle connector 604.

[0047] In some embodiments, continuing to refer to Figure 6 The optical fiber bundle connector 601 includes a second mounting bracket 606 and a set of optical fiber structure heads 603 integrally formed with the second mounting bracket 606, or the optical fiber bundle connector 601 includes a second mounting bracket 606 and a set of optical fiber structure heads 603 detachably screwed on the second mounting bracket 606. The optical fiber structure heads 603 are fixed with optical fibers, and the second mounting bracket 606 is further provided with at least two screws, and the optical fiber bundle interface 602 is provided with a set of notches corresponding to the optical fiber structure heads 603 and at least two threaded holes. When the optical fiber structure heads 603 are inserted into the corresponding notches, the screws are screwed into the corresponding threaded holes to complete the firm plugging of the optical fiber bundle connector 601 and the optical fiber bundle interface 602.

[0048] In some embodiments, in combination with Figure 6and Figure 7 The fnirs host 101 further comprises a first mounting frame 701 disposed in the shielded housing 202, the first mounting frame 701 is provided with a slot hole, the APD device 203 is embedded in one end of the slot hole, and a limiting thread is arranged on the inner wall of the slot hole. The slot of the fiber bundle interface 602 is arranged in one-to-one correspondence with the APD device 203.

[0049] The light receiving end of the fiber structure head 603 can be connected to a D probe, and the light emitting end of the fiber structure head 603 can be inserted into the slot hole on the first mounting frame 701 through the slot of the fiber bundle interface 602 and directly connected with the APD device 203. Specifically, the light emitting end of the fiber structure head 603 and the APD device 203 can form a gap therebetween, and a filter can be arranged in the gap to filter out interference light other than near-infrared light.

[0050] The APD device 203 can be stably installed through the first mounting frame 701, so that the APD device 203 and the fiber structure head 603 can maintain a relatively stable positional relationship.

[0051] The above-mentioned first mounting frame 701 can be configured as a plate, and the slot holes opened thereon can be arranged in one-to-one correspondence with the APD device 203.

[0052] Since the APD device 203 generates heat during operation, and the change of the magnetic field in the scanning room also causes the metal to heat up, the temperature and heat itself can affect the working condition of the APD device 203, and the temperature sensor 703 can be used to monitor the heating condition of the APD device 203 in real time. In some embodiments, the first mounting frame 701 is composed of ceramic matrix composite material, polyimide or carbon fiber. These materials do not interfere with the magnetic field during MRI scanning and do not produce artifacts, and have good thermal conductivity and hardness, which are suitable for use in the MRI scanning room.

[0053] In some embodiments, a plurality of temperature sensors 703 are embedded in the mounting frame 701, and each APD device 203 surrounds and is adjacent to a corresponding temperature sensor 703. In this way, the temperature of the heat conductor, i.e. the first mounting frame 701, which is in sufficient heat exchange with the APD device 203, is monitored by the temperature sensor 703 to indirectly monitor the temperature of the APD device 203.

[0054] In some embodiments, the plate surface of the first mounting frame 701 can be perpendicular to the axial direction of the fiber structure head 603.

[0055] Exemplarily, the light outlet end of the fiber structure head 603 can be sleeved with a threaded part, which can be connected with the first mounting frame 701 through threads, so that the fiber structure head 603 can be mounted to the first mounting frame 701 through the threaded part.

[0056] In some embodiments, a limiting thread is arranged in the hole wall of the slot hole of the first mounting frame 701, that is, after the threaded part of the fiber structure head 603 enters the position of the limiting thread, it cannot continue to enter inward. After the APD device 203 is embedded at one end of the slot hole, there is a certain gap, such as 1 mm, between the APD device 203 and the limiting thread. In this way, through the positioning of the limiting thread, when the fiber structure head 603 is mounted to the first mounting frame 701, the problem of crushing the APD device 203 to cause the APD device 203 to break is avoided, and the distance between the APD device 203 and the fiber structure head 603 can also be limited, so as to avoid affecting the light coupling efficiency due to too far distance.

[0057] Another design is that the shielding shell 202 contains a driving part (not shown in Figure 5 The corresponding S-probe on the headgear worn by the subject is installed with near-infrared LEDs, and the fnirs host 101 is connected to each near-infrared LED at the corresponding S-probe on the headgear through wires. In this case, the driving part can transmit a driving signal to each near-infrared LED at the corresponding S-probe on the headgear through wires, and each near-infrared LED generates near-infrared light based on the driving signal. That is, the shielding shell 202 includes a driving part, each near-infrared LED driven by the driving part is located at the corresponding S-probe on the headgear, and the driving part is connected to the corresponding S-probe through wires. The wires can be made of copper. Copper has higher electrical conductivity, generates less eddy current and less heat under a changing magnetic field, and has less difference in magnetic permeability with air, which can reduce the interference on the corresponding S-probe on the headgear, eddy current effect, heat generation and signal artifacts.

[0058] In a preferred embodiment, both the wires and the electronic devices are installed in the shielding shell 202, reducing the wires exposed to the magnetic field in the scanning hole, so as to avoid as much as possible the interference on the corresponding S-probe on the headgear.

[0059] In some embodiments, the near-infrared LED is preferably made of a material that does not contain ferromagnetic properties, such as but not limited to lead-free perovskite near-infrared LED, organic semiconductor and quantum dot (such as PbS quantum dot, Ag2S quantum dot) near-infrared LED, etc., which will not be described here.

[0060] In some embodiments, the fnirs host 101 further comprises a wire bundle interface and / or an optical fiber bundle interface, the wire bundle interface being configured to detachably plug the wire bundle, each near-infrared LED at the corresponding S-probe on the head cap being connected with a wire to form the wire bundle; the optical fiber bundle interface being configured to detachably plug the first optical fiber bundle and / or the second optical fiber bundle. The specific plugging manners have been listed above and will not be repeated here.

[0061] The light source part 205 or the driving part does not contain ferromagnetic material.

[0062] The main processor and processing circuit 204 can generate corresponding control logic and instructions according to the preset program or algorithm, and the instructions will be transmitted to the light source part 205 or the driving part. For example, the main processor and processing circuit 204 will send instructions to the driving part according to the requirements of near-infrared detection, so that the driving part drives the near-infrared LED to emit light according to a specific frequency and intensity.

[0063] The fnirs host 101 provided by the embodiments of the present application does not contain ferromagnetic material and has a small volume and a size suitable for being placed in the scanning hole of the MRI imaging system. Moreover, by arranging the optical fiber bundle interface and / or the wire bundle interface on the fnirs host 101, the wire bundle and the optical fiber bundle can be conveniently plugged on the fnirs host 101.

[0064] For example, before performing MRI and fnirs joint acquisition, the probes on the head cap worn by the subject are debugged. Two hosts can be prepared, one is a detection host placed in the scanning hole, and the other is a debugging host placed in the control room. The subject can connect the optical fiber bundle and / or the wire bundle of the probes on the head cap to the debugging host in the control room, debug each probe first, disconnect the connection with the debugging host after debugging, and then plug the optical fiber bundle and / or the wire bundle to the detection host after the subject enters the scanning room. At this time, only fine tuning is needed, thereby improving the efficiency of probe debugging.

[0065] In addition, when the fnirs host 101 does not include the optical fiber bundle interface and / or the wire bundle interface, due to the small size and light weight of the fnirs host 101, the subject can also wear a head cap and carry the fnirs host 101 in and out of the control room (the communication interface 201 is unplugged from the cable for communication with the host computer in the control room), and debug the probe on the head cap worn by the subject in the control room. After debugging, the subject keeps the wearing posture and carries the fnirs host 101 into the scanning room, places the fnirs host 101 into the scanning hole, and inserts the communication cable into the communication interface 201. In this way, the subject can conveniently carry the fnirs host 101 in and out of the scanning room, which can also improve the efficiency of probe debugging, and can ensure the stability of signal transmission.

[0066] In some embodiments, the wire includes a shielding layer, and the shielding layer is driven by a voltage follower. By using a voltage follower to drive the shielding layer, the potential fluctuation on the shielding layer can be effectively reduced, and the electromagnetic interference caused by the potential change can be reduced. At the same time, the high input impedance of the voltage follower can avoid the load effect on the circuit connected thereto, and ensure the stability of the reference voltage source or the related potential. By driving the wire shielding layer through the voltage follower in the scanning room instead of directly grounding, the common-mode interference signal caused by the strong magnetic field to the wire can be more effectively suppressed, the transmission quality of the electrical signal is ensured, and the reliability and accuracy of the detection system are improved.

[0067] In some embodiments, the fnirs host 101 further includes an optoelectronic converter to receive an optical synchronization trigger clock signal of an MRI scan sequence from a control system of a machine room via an optical fiber, and convert it into an electrical pulse to be transmitted to the main processor and processing circuit 204.

[0068] Specifically, the control system of the machine room is responsible for controlling the operation of the MRI scanning device, including the start, stop and setting of various parameters of the MRI scan sequence. Through the optical fiber, the machine room control system sends an optical synchronization trigger clock signal of the MRI scan sequence to the fnirs host 101, and the optical synchronization trigger clock signal carries the time information and synchronization instructions of the MRI scan, which is beneficial to realize the synchronous acquisition of fnirs and MRI.

[0069] The photoelectric converter converts the received optical synchronous trigger clock signal into an electrical pulse. Since the main processor and processing circuit 204 inside the fnirs host 101 usually process data and control in the form of electrical signals, the optical synchronous trigger clock signal is converted into an electrical pulse so that the main processor and processing circuit 204 can recognize and process it. This conversion ensures that the fnirs host 101 can accurately obtain the synchronization information of the MRI scan sequence, and the two can be clocked to synchronize with the MRI scan to achieve data acquisition.

[0070] In some embodiments, the fnirs host 101 also includes a memory for backing up all collected data, which can ensure that the collected data will not be lost in the event of device failure, power failure, or other failures. Moreover, the backed-up collected data can also be used for comparison and verification between different research projects, and also provides a basis for data quality control and auditing.

[0071] Before performing MRI and fnirs data acquisition, the host computer and the fnirs host 101 can be time-aligned, for example, the host computer and the fnirs host 101 can be time-aligned based on a marking device, and an alignment mark can be generated and stored in the memory. That is, the memory stores an alignment mark in the corresponding field, and the alignment mark indicates whether the fnirs host 101 has been time-aligned with the host computer before the scan is started.

[0072] When the fnirs host 101 is started, it is determined whether the fnirs host 101 has been time-aligned with the host computer based on the alignment mark, for example, if the memory stores the alignment mark, it is considered that the host computer and the fnirs host 101 have been time-aligned, and only after time alignment can the data be collected synchronously.

[0073] This is only an exemplary illustration and does not constitute a limitation on the specific manner.

[0074] In some embodiments, the fnirs host 101 is built-in with a secondary battery (not shown), which can provide power support for the fnirs host 101 without external power supply, ensuring the normal operation of the device. The secondary battery can provide stable voltage and current output for the fnirs host 101.

[0075] wherein, Figure 4 The battery shown can be a secondary battery, which is elevated from the bottom of the scan hole by a support platform, and the EEG amplifier, fnirs host 101 and secondary battery are stacked on the support platform to be close to the center of the scan hole.

[0076] For example, the fnirs host 101 with a built-in secondary battery can be charged outside the scanning room, and after the charging is completed, it can be placed in the scanning hole for use. The secondary battery can be other types of MRI-compatible batteries, such as sodium batteries with non-metallic casings, lithium-ion batteries with non-metallic casings, solid-state batteries with non-metallic casings, etc.

[0077] In addition, the fnirs host 101 can also not be built-in with a battery, but a special power supply unit is provided externally, which has the characteristics of MRI safety and can work safely and stably in the MRI scanning environment, without causing electromagnetic interference to the MRI equipment, nor being affected by the strong magnetic field of the MRI to cause performance degradation or safety problems.

[0078] In some embodiments of the present application, the processing circuit includes an anti-aliasing filter 206 configured to perform a low-pass operation with a cutoff frequency lower than the lower limit of the frequency of the radio frequency (RF) signals emitted by the MRI imaging system when it is working, and higher than twice the upper limit of the frequency of the near-infrared brain function imaging detection signal.

[0079] The MRI imaging system emits radio frequency (RF) signals when it is working, and the frequency range of these signals is wide. The anti-aliasing filter 206 sets the cutoff frequency lower than the lower limit of the frequency of the radio frequency (RF) signals emitted by the MRI imaging system when it is working, in order to effectively prevent the RF signals of the MRI from entering the processing circuit of the fnirs host 101, and avoid interfering with the near-infrared brain function imaging detection signal.

[0080] The cutoff frequency of the anti-aliasing filter 206 is set to be higher than twice the upper limit of the frequency of the near-infrared brain function imaging detection signal, so that when the detection signal is sampled and processed, the integrity and accuracy of the signal can be ensured, and high-frequency noise and other interference signals are prevented from passing through the filter, thereby improving the signal-to-noise ratio and resolution of the system, and ensuring the quality of the near-infrared brain function imaging detection signal. For example, the cutoff frequency of the anti-aliasing filter 206 can be set to 100Hz to 10kHz, which can effectively filter out the RF signals of the MRI and well preserve the near-infrared brain function imaging detection signal.

[0081] In some embodiments, the processing circuit further comprises an amplifier and an analog-to-digital converter 207, the amplifier being configured to receive the differential input signal to suppress common-mode interference caused by the MRI magnetic field. When the amplifier receives the differential input signal, a subtraction operation is performed on the two input signals. Since the common-mode interference has substantially the same magnitude and phase on both lines, the common-mode interference signal is greatly weakened or even completely cancelled out during the subtraction process. While the useful differential signal is normally amplified. In this way, the amplifier effectively suppresses the common-mode interference caused by the MRI magnetic field through processing of the differential input signal, thereby improving the quality and stability of the signal.

[0082] In some embodiments, the processing circuit further comprises an electrostatic discharge protection unit 208 configured to prevent electrostatic hazards caused by plugging of the wire harness. The electrostatic discharge protection unit 208 limits the voltage and current during electrostatic discharge by adopting a series of electrostatic protection measures, such as installing electrostatic discharge resistors, transient voltage suppression diodes (TVS) and other components. When static electricity is generated and accumulated to a certain extent, the electrostatic discharge protection unit 208 can quickly guide the static electricity to the ground or limit the transient high voltage generated by electrostatic discharge within a safe range, thereby protecting the electronic components in the fnirs host 101 from electrostatic hazards and ensuring the normal operation of the system and the stability of signal transmission.

[0083] In some embodiments, an fnirs system for use in cooperation with an MRI imaging system is provided, in particular, as shown in Figure 8 Fig. 8, comprising a head cap 801 for mounting a probe, an fnirs host 802 for use in cooperation with an MRI imaging system as described in various embodiments of the present application, a control system in a machine room and a host computer 803 in a control room, the MRI imaging system comprising a scan bore.

[0084] In some embodiments, the fnirs host 802 is sized to fit within the scan bore, placed within a predetermined peripheral space range at the isocenter of the scan bore. The fnirs host 802 is small and light in size, and the subject can conveniently carry the fnirs host 802 in and out of the scan room.

[0085] In some embodiments, a near-infrared LED is installed on the S-probe of the head cap 801, the near-infrared LED being connected to the fnirs host 802 via a wire, the near-infrared LED being free of ferromagnetic materials to avoid affecting the MRI magnetic field environment and damaging the equipment, and the length of the wire being less than 2.5 meters.

[0086] In some embodiments, the D-probe on the head cap 801 is connected to the fnirs host 802 via a first optical fiber bundle, the length of the first optical fiber bundle being less than 2.5 meters.

[0087] In some embodiments, the S-probes on the head cap 801 are connected to the fnirs host 802 via a second fiber bundle, the length of the second fiber bundle is less than 2.5 meters.

[0088] That is, the fnirs host 802 is placed in the scanning hole, which greatly shortens the length of the line connecting the probes on the head cap 801 and the fnirs host 802, and the length of the line is less than 2.5 meters, such as only 2 meters, 1.5 meters, 1 meter or 0.5 meter. Therefore, after wearing the head cap, the subject can conveniently separate from the fnirs host 802, and can directly carry the fnirs host 802 to move freely in and out of the scanning room.

[0089] In some embodiments, the control system sends an optical synchronization trigger clock signal of an MRI scan sequence, which is transmitted to the fnirs host 802 via a high-speed serial interface and an optical fiber, and the fnirs host 802 converts the optical synchronization trigger clock signal into an electrical pulse and transmits it to the host processor and processing circuit. The fnirs host 802 and the MRI imaging system can be time-aligned to achieve synchronous data acquisition.

[0090] In some embodiments, the upper computer 803 is configured to perform gradient artifact removal processing on the received fnirs detection data. The fnirs host 802 transmits fnirs detection data to the upper computer 803, and the upper computer 803 performs complex data processing and analysis, including performing gradient artifact (GA) removal processing on the received fnirs detection data. The GA removal processing can include at least one of AAS (adaptive averaging method), DAE (denoising autoencoder), deep learning network and LOGDAE. In some embodiments, the fnirs host 802 sends the synchronization time marker together with the fnirs detection data to the upper computer 803 for performing the GA removal processing.

[0091] Specifically, the optical synchronization trigger clock signal of the MRI scan sequence is converted into an electrical pulse and transmitted to the fnirs host 802, and the fnirs host 802 obtains a synchronization time marker based on the electrical pulse signal and sends it to the upper computer 803 together with the fnirs detection data. The synchronization time marker records the precise time information of data acquisition, which is of great significance for GA removal processing. Because the generation of gradient artifacts can be related to specific time points or time periods in the detection process, for example, it appears synchronously with a specific pulse sequence of the MRI scan. The upper computer 803 can use the synchronization time marker to associate and analyze the data with the time information, more accurately identify and locate the gradient artifacts, and thus use more targeted methods for removal, improving the effect and accuracy of artifact removal.

[0092] In the various embodiments described above, the processor may be a processing device that includes one or more general-purpose processing devices, such as a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), etc. More specifically, the processor may be a Complex Instruction Set Computing (CISC) microprocessor, a Reduced Instruction Set Computing (RISC) microprocessor, a Very Long Instruction Word (VLIW) microprocessor, a processor that runs other instruction sets, or a processor that runs a combination of instruction sets. The processor may also be one or more special-purpose processing devices, such as an Application-Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), a System-on-Chip (SoC), etc.

[0093] This application describes various operations or functions that can be implemented as software code or instructions, or defined as software code or instructions. Such content can be directly executable source code or differential code (“incremental” or “patch” code) (“object” or “executable” form). The software code or instructions can be stored in a computer-readable storage medium and, when executed, can cause a machine to perform the described functions or operations, and include any mechanism for storing information in a machine-accessible form, such as recordable or non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, etc.).

[0094] Furthermore, although exemplary embodiments have been described herein, their scope includes any and all embodiments based on this application that have equivalent elements, modifications, omissions, combinations (e.g., schemes involving intersections of various embodiments), adaptations, or alterations. Elements in the claims will be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, which will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered illustrative only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0095] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, which will be apparent to those of ordinary skill in the art upon reviewing the above description. Additionally, the various features described above can be grouped together or divided into separate features for the purpose of simplifying the present disclosure. This should not be interpreted as a requirement to practice any claim in its full scope unless the claim does not encompass additional embodiments to those that can be claimed. The scope of the application should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “comprising” are open-ended, that is, are intended to mean one or more items, products, or methods which can be purchased, used, or collected, e.g., “including” a fruit may mean that the fruit can be an apple, an orange, a banana, a grape, or any other fruit. Further, the terms “first” and “second” are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0096] The above embodiments are only exemplary embodiments of the present application, and are not intended to limit the present application, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements should also be considered to fall within the protection scope of the present application.

Claims

1. An fnirs host for use in conjunction with an MRI imaging system, characterized in that, The fnirs host is adapted to be placed in a predetermined peripheral space range of isocenter in a scanning hole of an MRI imaging system, and specifically comprises: a communication interface configured to be communicatively connected to a host computer in a control room in a wired manner without introducing ferromagnetic materials, to transmit fnirs detection data to the host computer; a shielding shell made of a first non-ferromagnetic metal, the shielding shell containing: a set of APD devices, each APD device being configured to be connected to a corresponding D probe on a headgear via a first optical fiber bundle to receive near-infrared light emitted from the head of a subject and convert it into an electrical signal, and the package of each APD device being made of a non-ferromagnetic material, and the metal used in the pins or plating of each APD device being a second non-ferromagnetic metal; a main processor and processing circuit configured to be electrically connected to the set of APD devices to process the electrical signals to obtain fnirs detection data, wherein the electrical devices and electrical connection lines use a third non-ferromagnetic metal; and a light source part for transmitting near-infrared light to a corresponding S probe on a headgear via a second optical fiber bundle, or a driving part for connecting to each near-infrared LED at the corresponding S probe on the headgear via an electrical wire to make it emit near-infrared light, the light source part or the driving part being operated under the control of the main processor and processing circuit, and neither of the light source part nor the driving part containing ferromagnetic materials.

2. The fnirs host for use in conjunction with an MRI imaging system of claim 1, wherein, The communication interface is connected to the host computer in the control room via an electrical wire or an optical fiber to transmit fnirs detection data.

3. Fnirs host for use in conjunction with an MRI imaging system according to claim 1 or 2, characterized in that, The electrical wire contains a shielding layer, and the shielding layer is driven by a voltage follower.

4. The fnirs host for use in conjunction with an MRI imaging system according to claim 1 or 2, characterized in that, Further comprising an optoelectronic converter to receive an optical synchronization trigger clock signal from an MRI scan sequence of a machine room control system via an optical fiber and convert it into an electrical pulse to transmit to the main processor and processing circuit.

5. The fnirs host for use in conjunction with an MRI imaging system according to claim 1 or 2, characterized in that, The fnirs host is built-in with a secondary battery.

6. The fnirs host for use with an MRI imaging system of claim 1 or 2, wherein, The light source part uses a set of near-infrared LED devices.

7. The fnirs host for use with an MRI imaging system according to claim 1 or 2, characterized in that, The first non-ferromagnetic metal is aluminum.

8. The fnirs host for use with an MRI imaging system of claim 1 or 2, wherein, The second non-ferromagnetic metal and the third non-ferromagnetic metal are copper.

9. The fnirs host for use with an MRI imaging system of claim 1, wherein, The processing circuit comprises: an anti-aliasing filter configured to perform low-pass operation at a cutoff frequency lower than the lower limit of the frequency of the RF signal emitted by the MRI imaging system when operating, and higher than twice the upper limit of the frequency of the near-infrared brain function imaging detection signal, with a stopband attenuation greater than a predetermined dB number; an amplifier and an analog-to-digital converter, the amplifier being used to receive a differential input signal to suppress common-mode interference caused by the MRI magnetic field.

10. The fnirs host for use with an MRI imaging system of claim 1, wherein, In the case of transmitting near-infrared light to the corresponding S probe on the headgear via a second optical fiber bundle, the fnirs host further comprises an optical fiber bundle interface; the optical fiber bundle interface is used to detachably plug the first optical fiber bundle and the second optical fiber bundle.

11. The fnirs host for use with an MRI imaging system of claim 1, wherein, The fnirs host further comprises a wire bundle interface and an optical fiber bundle interface, in the case that each near-infrared LED at the corresponding S-probe on the headgear is connected to the fnirs host via a wire to cause the near-infrared LED to emit near-infrared light, the wire bundle interface is used for detachably plugging the wire bundle, and the optical fiber bundle interface is used for detachably plugging the first optical fiber bundle.

12. The fnirs host for use in conjunction with an MRI imaging system of claim 11, wherein, The processing circuit further comprises: An electrostatic discharge protection unit configured to prevent electrostatic hazards caused by plugging of the wire bundle.

13. The fnirs host for use with an MRI imaging system of claim 1, wherein, The shielded housing has a first dimension, a second dimension, and a third dimension, wherein the first dimension is smaller than the second dimension, and the second dimension is smaller than the third dimension.

14. The fnirs host for use with an MRI imaging system of claim 1, wherein, Further comprising a memory for backing up all collected data.

15. The fnirs host for use with an MRI imaging system of claim 14, wherein, The corresponding field of the memory stores an alignment identifier, which indicates whether the fnirs host has been time-aligned with the host computer before the start of scanning. When the fnirs host is started, it is determined whether the fnirs host has been time-aligned with the host computer according to the alignment identifier.

16. An fnirs system for use in conjunction with an MRI imaging system, characterized in that, The headgear for mounting the probe, the fnirs host for use in cooperation with the MRI imaging system according to any one of claims 1 to 15, the control system in the machine room, and the host computer in the control room, wherein the MRI imaging system comprises a scanning hole.

17. The fnirs system for use with an MRI imaging system of claim 16, wherein, The S-probe on the headgear is provided with a near-infrared LED, the near-infrared LED is connected to the fnirs host via a wire, the near-infrared LED does not contain ferromagnetic material, and the length of the wire is less than 2.5 meters.

18. The fnirs system for use with an MRI imaging system of claim 16, wherein, The D-probe on the headgear is connected to the fnirs host via a first optical fiber bundle, and the length of the first optical fiber bundle is less than 2.5 meters.

19. The fnirs system for use with an MRI imaging system of claim 16, wherein, The S-probe on the headgear is connected to the fnirs host via a second optical fiber bundle, and the length of the second optical fiber bundle is less than 2.5 meters.

20. The fnirs system for use with an MRI imaging system of claim 16, wherein, The control system sends an optical synchronization trigger clock signal of an MRI scanning sequence to the fnirs host via a high-speed serial interface and an optical fiber, and the fnirs host converts the optical synchronization trigger clock signal into an electrical pulse and transmits it to the main processor and the processing circuit.

21. The fnirs system for use with an MRI imaging system of claim 16, wherein, The host computer is configured to perform gradient artifact removal processing on the received fnirs detection data.

22. The fnirs system for use with an MRI imaging system of claim 21, wherein, The gradient artifact removal processing adopts at least one of an adaptive averaging method, a denoising autoencoder, a deep learning network, and a LOGDAE.

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