FnIRs host used in cooperation with MRI imaging system and fnIRs system

Abstract

The invention provides an fnIRs host and an fnIRs system which are used in cooperation with an MRI (Magnetic Resonance Imaging) system. The fnirs host comprises a communication interface and a shielding shell, a group of APD devices are accommodated in the shielding shell, each APD device is respectively configured to be connected to a corresponding D probe on the head cap through a first optical fiber bundle, and metal adopted by a pin or a coating of each APD device is second non-ferromagnetic metal; the main processor and the processing circuit are configured to be electrically connected to a group of APD devices, and the adopted metal is third non-ferromagnetic metal; and the light source part or the driving part operates under the control of the main processor and the processing circuit, and the light source part or the driving part does not contain a ferromagnetic material. The fnirs host is small in size and can be placed in a scanning hole of an MRI scanning room, the length of an optical fiber on a head cap worn by a subject is shortened, and a probe on the head cap worn by the subject can be conveniently adjusted.

Description

Technical Field

[0001] This application relates to the technical field of near-infrared brain functional imaging, and particularly relates to a fnirs host and a fnirs system for collaborative use with an MRI imaging system. Background Art

[0002] Near-infrared brain functional imaging (fnirs) devices and magnetic resonance imaging (MRI) devices are two brain imaging technologies with different physical principles. The brain information obtained can be complementary at many levels, thus providing doctors with more comprehensive diagnostic information. Combining the two modalities of MRI and fnirs can more accurately diagnose and evaluate the brain function state. However, ferromagnetic materials are not allowed to be built into the MRI scanning room, and it is difficult to reasonably place the fnirs device in the radiology MRI scanning room.

[0003] The existing methods can be referred to Figure 1 . The host and the upper computer are placed outside the scanning room, for example, in the control room or the workstation. At the same time, waveguide holes are opened on the wall of the scanning room, and the optical fiber connected to the headcap worn by the subject is connected to the host outside the scanning room through the waveguide holes. The near-infrared light emitted outside the scanning room, such as by an LED, is transmitted to the S probe (emitting probe) on the headcap worn by the subject through the optical fiber passing through the wall, so as to emit near-infrared light to the subject's head.

[0004] However, placing both the host and the upper computer outside the scanning room results in an optical fiber passing through the wall being as long as 5 to 10 meters, which not only causes significant light attenuation, but also is prone to breakage due to its own weight during dragging. 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 an optical fiber 5 to 10 meters long to first debug the probe on the headcap and the fnirs detection signal in the control room, then drag the long optical fiber to the treatment room to inject medicine, and finally return to the scanning room, which is extremely inconvenient. Moreover, if the subject needs to be in the scanning room, after removing the optical fibers corresponding to each probe and then going to inject medicine, when the subject returns to the scanning room, the optical fibers need to be reinstalled for each probe one by one. After installation, the probe and the fnirs detection signal still need to be debugged. This not only takes a long time to operate, but also has a high degree of instability. Summary of the Invention

[0005] In view of the above technical problems existing in the prior art, this application is proposed. This application provides a fnirs host and a fnirs system for collaborative use with an MRI imaging 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, so as to be able to shorten the length of the optical fiber between the probe on the headcap and the fnirs host, enabling the subject to move conveniently, and can also simplify the steps of debugging the probe for the subject and reduce the debugging operation time.

[0006] According to the first aspect of the present application, there is provided a fnirs main unit for collaborative use with an MRI imaging system. The size of the fnirs main unit is adapted to be placed within a predetermined peripheral space range of the isocenter in the scanning hole of the MRI imaging system. The fnirs main unit specifically includes a communication interface and a shielding housing. The communication interface is configured to communicatively connect to a host computer in the control room in a wired manner without introducing ferromagnetic materials, so as to transmit fnirs detection data thereto. The shielding housing is made of a first non-ferromagnetic metal. The shielding housing houses: a group of APD devices, each APD device is respectively configured to be connected to a corresponding D probe on the headcap 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 is made of a non-ferromagnetic material, and the pins or coatings of each APD device are made of a second non-ferromagnetic metal; a main processor and a processing circuit, which are configured to be electrically connected to the group of APD devices to process the electrical signal to obtain fnirs detection data, and the electrical devices and electrical connection lines therein are made of a third non-ferromagnetic metal; and a light source unit for transmitting near-infrared light to the corresponding S probe on the headcap via a second optical fiber bundle, or a driving unit for connecting each near-infrared LED to the corresponding S probe on the headcap via a wire to cause it to emit near-infrared light. The light source unit or the driving unit operates under the control of the main processor and the processing circuit, and neither the light source unit nor the driving unit contains ferromagnetic materials.

[0007] According to the second aspect of the present application, there is provided a fnirs system for collaborative use with an MRI imaging system, including a headcap for mounting a probe, a fnirs main unit for collaborative use with an MRI imaging system as described in various embodiments of the present application, a control system in the machine room, and a host computer in the control room. The MRI imaging system includes a scanning hole.

[0008] Compared with the prior art, the beneficial effects of the embodiments of the present application are as follows: The fnirs main unit provided by the embodiments of the present application has a size adapted to be placed within a predetermined peripheral space range of the isocenter in the scanning hole of the MRI imaging system. The shielding housing is made of a first non-ferromagnetic metal. The pins or coatings of the APD devices in the shielding housing are made of a second non-ferromagnetic metal. The electrical devices and electrical connection lines are made of a third non-ferromagnetic metal. Neither the light source unit nor the driving unit contains ferromagnetic materials. Therefore, the fnirs main unit can be placed in the scanning hole of the MRI imaging system without affecting the magnetic field environment and without causing harm to the equipment and personnel.

[0009] In this embodiment, the fnirs main unit is placed inside the scanning hole and communicatively connected to the host computer in the control room in a wired manner without introducing magnetic materials through the communication interface of the fnirs main unit. The fnirs main unit is connected to the probe on the headcap worn by the subject through a second optical fiber or wire. Since the fnirs main unit is directly placed inside the scanning hole, the distance between the fnirs main unit and the subject's headcap is relatively short, shortening the length of the second optical fiber or wire (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 around with the second optical fiber or wire and the fnirs main unit. Or, the fnirs main unit can be always placed inside the scanning hole. After removing the second optical fiber or wire, the subject can conveniently move around with the second optical fiber or wire and then reconnect the second optical fiber or wire to the fnirs main unit after returning to the scanning room.

[0010] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above description and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings, which are not necessarily to scale, the same reference numerals may describe similar components in different views. Similar reference numerals with alphabetical suffixes or different alphabetical suffixes may represent different examples of similar components. The drawings generally illustrate various embodiments by way of example and not limitation, and are used in conjunction with the specification and the claims to explain the disclosed embodiments. Such embodiments are illustrative and exemplary and are not intended to be an exhaustive or exclusive embodiment of the method, apparatus, system, or non-transitory computer-readable medium having instructions for implementing the method.

[0012] Figure 1 FIG. shows a schematic structural diagram of a fnirs main unit used in conjunction with an MRI imaging system according to the prior art.

[0013] Figure 2 FIG. shows a schematic diagram of a fnirs main unit provided according to an embodiment of the present application placed inside a scanning hole for use in conjunction with an MRI imaging system.

[0014] Figure 3 FIG. shows a schematic diagram of the spatial variation of the gradient magnetic field in an MRI imaging system according to an embodiment of the present application.

[0015] Figure 4 FIG. shows a schematic diagram of providing a support platform within a predetermined peripheral space range of the isocenter inside the scanning hole for placing related devices such as an electroencephalogram amplifier used in conjunction with an MRI system.

[0016] Figure 5 Shows a schematic structural diagram of a fnirs mainframe for use in conjunction with an MRI imaging system according to an embodiment of the present application.

[0017] Figure 6 Shows a schematic structural diagram of an optical fiber bundle interface, an optical fiber bundle connector, a wire bundle interface, and a wire bundle connector according to an embodiment of the present application.

[0018] Figure 7 Shows a schematic structural diagram of a first mounting bracket inside the mainframe according to an embodiment of the present application.

[0019] Figure 8 Shows a schematic diagram of a fnirs system for use in conjunction with an MRI imaging system according to an embodiment of the present application. Detailed implementation

[0020] To enable those skilled in the art to better understand the technical solutions of the present application, the present application will be described in detail below in conjunction with the accompanying drawings and specific implementation manners. The embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, but it is not a limitation to the present application.

[0021] The "first", "second" and similar terms used in the present application do not indicate any order, quantity or importance, but are only used for distinction and convenience in expression, but do not rigidly limit that "first" and "second" must be different. For example, the "first non-ferromagnetic metal" and the "second non-ferromagnetic metal" may be the same non-ferromagnetic metal or different non-ferromagnetic metals. The terms "including" or "comprising" and similar terms used in the present application mean that the elements before the term cover the elements listed after the term, and do not exclude the possibility of also covering other elements. In the present application, the arrows shown in the figures for each step are only examples of the execution order and not limitations. The technical solutions of the present application are not limited to the execution order described in the embodiments. Each step in the execution order can be executed together, can be decomposed, and can be reordered as long as it does not affect the logical relationship of the execution content.

[0022] All terms used in the present application (including technical terms or scientific terms) have the same meaning as understood by those of ordinary skill in the art to which the present application pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such here. Technologies and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies and devices should be regarded as part of the specification.

[0023] In some embodiments of the present application, a fnirs host for collaborative use with an MRI imaging system is provided. As Figure 2 shown, the fnirs host 101 is adapted to be placed within a predetermined peripheral space range of the isocenter in the scan hole of the MRI imaging system.

[0024] During the process of MRI image acquisition, the gradient magnetic field plays a key role in spatial positioning. By applying gradient magnetic fields in three directions (usually the x-direction (transverse), y-direction (height direction), and z-direction (longitudinal)), the signal characteristics at different positions in space are made different. As Figure 3 shown, the intensity of the gradient magnetic field varies with the radial distance from the isocenter (the distance from the isocenter in the x-y cross-section). The intensity of the gradient magnetic field is the smallest at the isocenter, and the farther away from the isocenter, the more obvious the change in the gradient magnetic field. The rate of change of the magnetic field intensity is the largest at the edge of the gradient coil.

[0025] Thus, by placing the fnirs host 101 as centered as possible in the scan hole, the magnetic field change at the position where the fnirs host 101 is located is smoother, and the induced electromagnetic force and eddy currents are smaller. Thereby, the influence of the electromagnetic force on the fnirs host 101 can be reduced, avoiding displacement or damage of the components of the fnirs host 101 due to force. At the same time, the heat generated by the eddy currents and the interference to the MRI magnetic field are also reduced, which is beneficial to ensuring the normal operation of the fnirs device and the quality of the MRI image.

[0026] In some embodiments, a support platform can also be provided within a predetermined peripheral space range of the isocenter in the scan hole to place related devices such as an electroencephalogram amplifier used in conjunction with the MRI system. As Figure 2 and Figure 4 shown, the support platform is raised from the bottom of the scan hole, so that the electroencephalogram amplifier and the fnirs host 101 placed on the support platform are closer to the center of the scan hole.

[0027] The complete site layout of the MRI imaging system mainly includes a control room (also known as the operation room) where MRI professionals operate the MRI equipment, a scanning room directly opposite and connected to the control room (i.e., the place where patients undergo scans, also known as the scanning chamber), and a machine room next to the scanning room (which houses various cabinets related to MRI, including the radio frequency transmission system, gradient emission system, radio frequency reception and reconstruction system, as well as the magnet refrigeration system and power supply, etc., also known as the equipment room). This site layout may also include a workstation (i.e., the place where doctors view and analyze MRI images) and a treatment room. Among them, in some cases, the workstation and the control room may also be integrated. When using modalities such as EEG and PET in conjunction with MRI, conductive gel or contrast agent is usually applied to the subject in the treatment room. The fnirs host 101 specifically includes a communication interface 201, a shielding housing 202, a group of APD devices 203 housed in the shielding housing 202, a main processor and processing circuit 204, and a light source unit or drive unit 205, which will be described in detail below in conjunction with Figure 5 for detailed description.

[0028] As Figure 5 shown, the communication interface 201 is configured to communicably connect to a host computer in the control room (also known as the operation room) in a wired manner that does not introduce ferromagnetic materials, so as to transmit fnirs detection data to it. Communication cables can be passed through openings (such as reserved waveguide holes) in the wall of the scanning room.

[0029] Among them, 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 passes through the hole in the wall and is connected to the host computer in the control room. That is to say, 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 used for communication can be basically fixed, such as being plugged into the communication interface 201 in a pluggable manner. Once the fnirs host 101 needs to be moved, the wire or optical fiber used for communication can be unplugged from the communication interface 201, and then plugged back into the communication interface 201 after the fnirs host 101 returns to its position in the scanning hole. In this way, the wire or optical fiber used 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 activities, nor will it affect the accuracy of the signal.

[0030] In addition, the fnirs host 101 and the host computer can also communicate through a wireless transmission method. The wireless transmission method includes point-to-point communication in the 5G communication mode, Wifi direct (without the need for a router) communication mode, etc., which are not limited herein.

[0031] The shielding housing 202 is made of a first non-ferromagnetic metal. Metals such as aluminum, copper, gold, and silver are all non-ferromagnetic metals. In a preferred embodiment, the first non-ferromagnetic metal is aluminum. Aluminum metal is inexpensive, has a relatively small density and is light in weight, which is convenient for installation and movement. Making the shielding housing 202 of aluminum can effectively shield the strong magnetic field generated by the MRI imaging system and the electromagnetic waves in the surrounding environment.

[0032] In some other embodiments of the present application, the shielding housing 202 has a first dimension with a first size, a second dimension with a second size, and a third dimension with a third size. Among them, the first size is smaller than the second size, and the second size is smaller than the third size.

[0033] 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 cross-section of the shielding housing 202 in the x-y plane is a flat shape, which is convenient for stacking with other combined devices such as electroencephalogram amplifiers. When the fnirs host 101 is stacked with other devices, it is necessary to keep the radial deviation from the isocenter. Further, by setting the second size to be smaller than the third size, the largest third size of the shielding housing 202 is along the z-axis direction (return to see Figure 3 ), and the rate of change of the gradient magnetic field is relatively low over a sufficient length in the z-axis direction. In this way, a position with a relatively low rate of change of the gradient magnetic field can be found along the z-axis direction to place the shielding housing 202.

[0034] Returning to the embodiments of the present application, each APD device 203 is respectively configured to be connected to the corresponding D probe (receiving probe) on the headgear via a first optical fiber bundle to receive the near-infrared light emitted from the subject's head and convert it into an electrical signal. Moreover, the packages of each APD device 203 are made of non-ferromagnetic materials, and the metals used for the pins or coatings of each APD device 203 are second non-ferromagnetic metals.

[0035] The APD device 203 is an avalanche photodiode. The APD device 203 is arranged in the fnirs host 101. The APD device 203 is connected to the corresponding D probe on the headgear through 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 of the subject's headgear to the APD device 203. This connection method can ensure that the loss of near-infrared light during transmission is small, and can accurately guide the near-infrared light to the corresponding APD device 203 for detection, while reducing the mutual interference between the lines (because it is an optical fiber bundle) exposed in the scan hole and the magnetic field.

[0036] The APD device 203 utilizes the internal photoelectric effect to convert the received near-infrared light into electrical signals. Subsequently, these electrical signals can be amplified, processed, etc. by the main processor and the processing circuit 204, without limitation here.

[0037] The encapsulation of each APD device 203 is made of non-ferromagnetic material to avoid interfering with the magnetic field strength of the MRI imaging system, affecting the imaging quality, and avoiding damaging the equipment or causing harm to the examinee.

[0038] In this embodiment, the main processor and the processing circuit 204 are configured to be electrically connected to a group of the APD devices 203 to process the electrical signals to obtain fnirs detection data, and the metals used for the electrical devices and electrical connection lines therein are the third non-ferromagnetic metal.

[0039] In some embodiments, the second non-ferromagnetic metal and the third non-ferromagnetic metal are copper. Copper has a higher electrical conductivity, generates less eddy current and less heat under a changing magnetic field, and has a smaller magnetic permeability difference from air, which can reduce the interference with the magnetic field, eddy current effect, heat generation, and signal artifacts.

[0040] Specifically, after the APD device 203 converts the received near-infrared light emitted from the examinee's head into electrical signals, these electrical signals are transmitted to the main processor and the processing circuit 204 through electrical connection. These electrical signals contain physiological information related to the examinee's head tissue, but the electrical signals may be relatively weak and may be mixed with noise and other interference factors. The main processor and the processing circuit 204 perform a series of processing operations on the received electrical signals, including: amplifying the signal to increase the signal strength to a level that can be effectively analyzed; filtering operation to remove high-frequency noise or other irrelevant interference components in the signal and improve the signal quality; analog-to-digital conversion to convert the continuous analog electrical signal into a digital signal for further analysis and processing by a computer or other digital processing devices. In addition, it may also include processing steps such as feature extraction and data correction of the signal to highlight the feature information related to fnirs detection.

[0041] After a series of processing, the main processor and the processing circuit 204 convert the original electrical signals into fnirs detection data. This fnirs detection data is transmitted to the host computer in the control room in a wired manner through the communication interface 201 based on the communication interface circuit, for the host computer to perform specific analysis based on the fnirs detection data to obtain physiological parameter-related values, waveforms, or images such as blood oxygen parameters and blood flow changes.

[0042] In this embodiment, the corresponding D probes on the headgear worn by the examinee are connected to the fnirs host 101 via optical fibers, while the corresponding S probes can adopt different designs.

[0043] For example, in one design, a light source unit 205 is accommodated in a shielding housing 202. The light source unit 205 employs a group of near-infrared LED devices and also includes a light source driving circuit, which can drive the near-infrared LEDs to emit near-infrared light. There are no electronic devices provided inside the corresponding S probe on the headgear worn by the subject. In this case, the light source unit 205 emits near-infrared light, and the near-infrared light is transmitted to the corresponding S probe on the headgear via the second optical fiber bundle. That is to say, the shielding housing 202 includes the light source unit 205 that transmits near-infrared light to the corresponding S probe on the headgear via the second optical fiber bundle.

[0044] In some embodiments, the fnirs host 101 further includes an optical fiber bundle interface for detachably plugging in an optical fiber bundle. The optical fiber bundle includes a first optical fiber bundle and / or a second optical fiber bundle. Specifically, a fiber bundle connector is formed at one end of the optical fiber bundle away from the probe, and the optical fiber bundle interface is detachably plugged with the fiber bundle connector. The fiber bundle connector includes a first fiber bundle connector and / or a second fiber bundle connector. Among them, the first fiber bundle connector is formed by converging the ends of the first optical fiber bundle away from the D probe, and the second fiber bundle connector is formed by converging the ends of the second optical fiber bundle away from the S probe.

[0045] Exemplarily, Figure 6 The shown fiber bundle connector 601 can be plugged into the optical fiber bundle interface 602. The fiber bundle connector 601 can be a first fiber bundle connector, or a second fiber bundle connector, or both a first fiber bundle connector and a second fiber bundle connector. In addition, the fnirs host 101 may further include a wire bundle interface 605 for detachably plugging in a wire bundle. Specifically, a wire bundle connector 604 is formed at one end of the wire bundle away from the S probe, and the wire bundle interface 605 is detachably plugged with the wire bundle connector 604.

[0046] In some embodiments, continuing to refer to Figure 6 , the fiber bundle connector 601 includes a second mounting bracket 606 and a group of optical fiber structure heads 603 integrally formed therewith; or, the fiber bundle connector 601 includes a second mounting bracket 606 and a group of optical fiber structure heads 603 detachably screwed onto the second mounting bracket 606. An optical fiber is fixed in each optical fiber structure head 603. The second mounting bracket 606 is further provided with at least two screws. The optical fiber bundle interface 602 is provided with a group of notches corresponding to the optical fiber structure heads 603 one by one and at least two threaded holes. When the optical fiber structure heads 603 are all inserted into the corresponding notches, the screws are screwed into the corresponding threaded holes to complete the firm plugging of the fiber bundle connector 601 and the optical fiber bundle interface 602.

[0047] In some embodiments, in combination with Figure 6and Figure 7 The fnirs host 101 further includes a first mounting bracket 701 disposed within the shielding housing 202. The first mounting bracket 701 is provided with a slot. The APD device 203 is embedded at one end of the slot, and the inner wall of the slot is provided with a limiting thread. The notches on the fiber bundle interface 602 are arranged in one-to-one correspondence with the APD device 203.

[0048] The light-receiving end of the fiber structure head 603 can be connected to the D probe. The light-emitting end of the fiber structure head 603 can be inserted into the slot on the first mounting bracket 701 through the notch on the fiber bundle interface 602 and directly connected to the APD device 203. Among them, optical fibers are fixed in each fiber structure head 603. By inserting the fiber structure head 603 into the corresponding notch, an optical signal is transmitted to the APD device 203. Specifically, there may be a gap between the light-emitting end of the fiber structure head 603 and the APD device 203, and a filter may be provided within the gap between the two to filter out interfering light other than near-infrared light.

[0049] The APD device 203 can be stably installed through the first mounting bracket 701, so that the APD device 203 and the fiber structure head 603 can maintain a relatively stable positional relationship.

[0050] The above-mentioned first mounting bracket 701 can be configured as a plate shape, and the slots opened thereon are arranged in one-to-one correspondence with the APD device 203.

[0051] Since the APD device 203 generates heat during operation, and the magnetic field change in the scanning room can also cause the metal to heat up, temperature and heat itself will affect the working condition of the APD device 203. A temperature sensor 703 can be used to monitor the heat generation of the APD device 203 in real time. In some embodiments, the first mounting bracket 701 is made of a ceramic matrix composite material, polyimide or carbon fiber. These materials will not interfere with the magnetic field during the MRI scanning process and will not generate artifacts, and they all have good thermal conductivity and hardness, and are suitable for use in the MRI scanning room.

[0052] In some embodiments, a plurality of temperature sensors 703 are embedded in the mounting bracket 701, and each APD device 203 surrounds and is adjacent to the corresponding temperature sensor 703. In this way, by using the temperature sensor 703 to monitor the temperature of the first mounting bracket 701, which is a heat conductor that has sufficient heat exchange with the APD device 203, the temperature of the APD device 203 is indirectly monitored.

[0053] In some embodiments, the plane of the first mounting bracket 701 can be perpendicular to the axial direction of the fiber structure head 603.

[0054] Exemplarily, a threaded member may be sleeved on the light-emitting end of the optical fiber structure head 603, and the threaded member may be threadedly connected to the first mounting bracket 701, so that the optical fiber structure head 603 can be mounted on the first mounting bracket 701 through the threaded member.

[0055] In some embodiments, a limiting thread is provided on the inner wall of the slot hole of the first mounting bracket 701, that is, after the threaded member of the optical fiber structure head 603 enters the position of the limiting thread, it cannot continue to enter inward. There is a certain gap, such as 1 mm, between the APD device 203 and the limiting thread after the APD device 203 is embedded at one end of the slot hole. In this way, through the positioning of the limiting thread, when the optical fiber structure head 603 is mounted on the first mounting bracket 701, the problem of crushing the APD device 203 due to pressing the APD device 203 can be avoided, and the distance between the APD device 203 and the optical fiber structure head 603 can be limited, so as to avoid affecting the optical coupling efficiency due to too far a distance.

[0056] Another design is that a driving part (not shown in Figure 5 is accommodated in the shielding housing 202, and a near-infrared LED is installed in the corresponding S probe on the headgear worn by the subject. The fnirs host 101 is connected to each near-infrared LED at the corresponding S probe on the headgear via an electric wire. 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 the electric wire, and each near-infrared LED generates near-infrared light based on the driving signal. That is to say, the shielding housing 202 includes a driving part, and the driven near-infrared LEDs are located at the corresponding S probes on the headgear, and the driving part is connected to the corresponding S probe via an electric wire. The electric wire can be made of copper. Copper has a higher electrical conductivity, less eddy current and less heat generation under a changing magnetic field, and a smaller magnetic permeability difference from air, which can reduce magnetic field interference, eddy current effect, heat generation and signal artifacts.

[0057] In a preferred embodiment, the electric wire and the electronic device are both installed in the shielding housing 202, reducing the electric wire exposed to the magnetic field in the scanning hole, so as to avoid interfering with the time-division lighting of the corresponding S probe on the headgear as much as possible.

[0058] In some embodiments, the near-infrared LED is preferably made of a material that does not contain ferromagnetic materials, such as but not limited to lead-free perovskite near-infrared LEDs, organic semiconductors, and quantum dot (such as PbS quantum dots, Ag2S quantum dots) near-infrared LEDs, etc., which will not be elaborated here.

[0059] In some embodiments, the fnirs host 101 further includes a wire harness interface and / or an optical fiber bundle interface. Each near-infrared LED at the corresponding S probe on the headcap is connected with a wire to form a wire harness, and the wire harness interface is used for detachably plugging the wire harness; the optical fiber bundle interface is used for detachably plugging the first optical fiber bundle and / or the second optical fiber bundle. The specific plugging methods have been listed above and will not be elaborated here.

[0060] Wherein, the light source unit 205 or the driving unit operates under the control of the main processor and the processing circuit 204, and neither the light source unit 205 nor the driving unit contains ferromagnetic materials.

[0061] The main processor and the processing circuit 204 can generate corresponding control logics and instructions according to a preset program or algorithm, and these instructions will be transmitted to the light source unit 205 or the driving unit. For example, the main processor and the processing circuit 204 will send instructions to the driving unit according to the requirements of near-infrared detection, so that it drives the near-infrared LED to emit light at a specific frequency and intensity.

[0062] The fnirs host 101 provided by the embodiments of the present application does not contain ferromagnetic materials, and has a small volume, and its size is suitable for being placed in the scanning hole of the MRI imaging system. Moreover, by providing an optical fiber bundle interface and / or a wire harness interface on the fnirs host 101, the portable plugging of the wire harness and the optical fiber bundle on the fnirs host 101 can be realized.

[0063] For example, before performing combined acquisition of MRI and fnirs, when debugging the probes on the headcap worn by the subject, two hosts can be prepared. One is the detection host, which is placed in the scanning hole, and the other is the debugging host, which is placed in the control room. The subject can connect the optical fiber bundle and / or the wire harness of the probes on the headcap to the debugging host in the control room, first debug each probe, and after debugging, disconnect the connection with the debugging host. After the subject enters the scanning room, plug the optical fiber bundle and / or the wire harness into the detection host, and only fine-tuning is required at this time, thereby improving the efficiency of probe debugging.

[0064] In addition, when the fnirs host 101 does not include a fiber optic bundle interface and / or a wire bundle interface, since the fnirs host 101 is small and lightweight, the subject can also wear the headcap and carry the fnirs host 101 in and out of the control room (removing the cable for communicating with the upper computer in the control room), and debug the probes on the headcap 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 in place in the scanning hole, and inserts the communication cable into the communication interface 201. In this way, the subject can carry the fnirs host 101 in and out of the scanning room conveniently, improve the efficiency of probe debugging, and ensure the stability of signal transmission.

[0065] 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 potential changes can be reduced. At the same time, the high input impedance of the voltage follower can avoid generating a load effect on the connected circuit and ensure the stability of the reference voltage source or related potential. Driving the wire shielding layer by a voltage follower in the scanning room instead of directly grounding can more effectively suppress the common-mode interference signal brought by the strong magnetic field to the wire, ensure the transmission quality of the electrical signal, and improve the reliability and accuracy of the detection system.

[0066] In some embodiments, the fnirs host 101 further includes an optoelectronic converter to receive an optical synchronous trigger clock signal of the MRI scan sequence from the control system in the machine room via an optical fiber and convert it into an electrical pulse for transmission to the main processor and the processing circuit 204.

[0067] Specifically, the control system in the machine room is responsible for controlling the operation of the MRI scanning device, including starting, stopping the MRI scan sequence, and setting various parameters. Through the optical fiber, the control system in the machine room sends the optical synchronous trigger clock signal of the MRI scan sequence to the fnirs host 101. The optical synchronous trigger clock signal carries the time information and synchronization instructions of the MRI scan, which is beneficial to realizing the synchronous acquisition of fnirs and MRI. The optoelectronic converter converts the received optical synchronous trigger clock signal into an electrical pulse. Since the main processor and the processing circuit 204 inside the fnirs host 101 usually process and control data in the form of electrical signals, the optical synchronous trigger clock signal is converted into an electrical pulse so that the main processor and the 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. The two can achieve clock alignment and can realize data acquisition synchronously with the MRI scan.

[0068] In some embodiments, the fnirs host 101 further includes a memory, which is used to back up all the collected data, ensuring that the collected data will not be lost in case of equipment failures, power outages and other faults. Moreover, the backed-up collected data can also be used for comparison and verification between different research projects, and provides a basis for data quality control and auditing.

[0069] Before performing MRI and fnirs data collection, the host computer and the fnirs host 101 can be time-aligned first. For example, the host computer and the fnirs host 101 can be time-aligned based on a marking device, and an alignment identifier is generated and stored in the memory. That is to say, the alignment identifier is stored in the corresponding field of the memory, and the alignment identifier indicates whether the fnirs host 101 has been time-aligned with the host computer before the scan starts.

[0070] When the fnirs host 101 is powered on and started, it is judged whether it has been time-aligned with the host computer through the alignment identifier. For example, if the alignment identifier is stored in the memory, it is considered that the host computer and the fnirs host 101 have been time-aligned, and only after the time alignment can the data be synchronously collected.

[0071] This is only an exemplary illustration and does not constitute a limitation on the specific method.

[0072] In some embodiments, the fnirs host 101 is built-in with a secondary battery (not shown), and the secondary battery can provide power support for the fnirs host 101 without external power access, ensuring the normal operation of the device. The secondary battery can provide a stable voltage and current output for the fnirs host 101.

[0073] Among them, Figure 4 The shown battery can be a secondary battery, which is raised from the bottom of the scan hole through a support platform, and an electroencephalogram amplifier, the fnirs host 101 and the secondary battery are stacked on the support platform to be close to the center of the scan hole.

[0074] For example, the fnirs host 101 with a built-in secondary battery can be charged outside the scan room, and can be placed in the scan hole for use after charging. The secondary battery can be other types of batteries compatible with MRI, such as sodium batteries with non-metallic shells, lithium-ion batteries with non-metallic shells, solid-state batteries with non-metallic shells, etc.

[0075] In addition, the fnirs host 101 may not have a built-in battery, but instead provide an external dedicated power supply unit. The dedicated power supply unit has the characteristics of being MRI-safe and can work safely and stably in the MRI scanning environment, without generating electromagnetic interference to the MRI device and without suffering from performance degradation or safety problems due to the influence of the strong MRI magnetic field.

[0076] In some embodiments of the present application, the processing circuit includes an anti-aliasing filter 206. The anti-aliasing filter 206 is configured to perform a low-pass operation with a cut-off frequency lower than the lower limit of the radio frequency (RF) signal frequency emitted when the MRI imaging system operates and higher than twice the upper limit of the near-infrared brain function imaging detection signal frequency, and the stopband attenuation is greater than a predetermined dB value.

[0077] When the MRI imaging system operates, it emits radio frequency (RF) signals with a relatively wide frequency range. The anti-aliasing filter 206 is set with a cut-off frequency lower than the lower limit of the RF signal frequency emitted when the MRI imaging system operates 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 signals.

[0078] The cut-off frequency of the anti-aliasing filter 206 is set higher than twice the upper limit of the near-infrared brain function imaging detection signal frequency. In this way, when sampling and processing the detection signals, the integrity and accuracy of the signals can be ensured, preventing high-frequency noise and other interference signals 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 signals. For example, the cut-off frequency of the anti-aliasing filter 206 can be set between 100 Hz and 10 kHz, which can well filter out the RF signals of the MRI and well retain the near-infrared brain function imaging detection signals.

[0079] In some embodiments, the processing circuit further includes an amplifier and an analog-to-digital converter 207. The amplifier is used to receive differential input signals to suppress the common-mode interference brought by the MRI magnetic field. When the amplifier receives differential input signals, it will perform a subtraction operation on the two input signals. Since the common-mode interference is basically the same in magnitude and phase on the two lines, the common-mode interference signal will be greatly weakened or even completely cancelled during the subtraction process. And the useful differential signals will be normally amplified. In this way, the amplifier effectively suppresses the common-mode interference brought by the MRI magnetic field through the processing of the differential input signals, improving the quality and stability of the signals.

[0080] In some embodiments, the processing circuit further includes an electrostatic discharge protection unit 208 configured to prevent electrostatic hazards caused by the insertion 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 accumulates 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 the 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.

[0081] In some embodiments, there is provided a fnirs system for use in conjunction with an MRI imaging system. Specifically, as Figure 8 shown, it includes a headcap 801 for mounting probes, a fnirs host 802 for use in conjunction with an MRI imaging system as described in various embodiments of the present application, a control system in the machine room, and a host computer 803 in the control room. The MRI imaging system includes a scanning aperture.

[0082] Among them, the size of the fnirs host 802 is adapted to the scanning aperture and is placed within a predetermined peripheral space range at the isocenter in the scanning aperture. The fnirs host 802 is small and lightweight, and the subject can conveniently move around inside and outside the scanning room with the fnirs host 802.

[0083] In some embodiments, near-infrared LEDs are installed at the S probes on the headcap 801. The near-infrared LEDs are connected to the fnirs host 802 via wires. The near-infrared LEDs do not contain ferromagnetic materials to avoid the influence of ferromagnetic materials on the MRI magnetic field environment and damage to the equipment. The length of the wires is less than 2.5 meters.

[0084] In some embodiments, the D probes on the headcap 801 are connected to the fnirs host 802 via a first optical fiber bundle. The length of the first optical fiber bundle is less than 2.5 meters.

[0085] In some embodiments, the S probes on the headcap 801 are connected to the fnirs host 802 via a second optical fiber bundle. The length of the second optical fiber bundle is less than 2.5 meters.

[0086] That is to say, placing the fnirs host 802 inside the scanning hole greatly shortens the length of the connection line between the probe on the headcap 801 and the fnirs host 802. The length of the line can be less than 2.5 meters, such as only 2 meters, 1.5 meters, 1 meter or 0.5 meters. Therefore, after the subject wears the headcap, they can easily disconnect from the fnirs host 802 and directly carry the fnirs host 802 to move freely inside and outside the scanning room.

[0087] In some embodiments, the control system sends an optical synchronous trigger clock signal of the MRI scan sequence, which is transmitted to the fnirs host 802 via a high-speed serial interface and an optical fiber. The fnirs host 802 converts the optical synchronous trigger clock signal into an electrical pulse and transmits it to the main processor and the processing circuit, enabling time alignment between the fnirs host 802 and the MRI imaging system and synchronous data acquisition.

[0088] In some embodiments, the host computer 803 is configured to perform gradient artifact removal processing on the received fnirs detection data. The fnirs host 802 transmits the fnirs detection data to the host computer 803, and the host 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 may 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 stamp together with the fnirs detection data to the host computer 803 for it to perform GA removal processing.

[0089] Specifically, the optical synchronous trigger clock signal of the MRI scan sequence is converted into an electrical pulse and transmitted to the fnirs host 802. The fnirs host 802 obtains the synchronization time stamp based on the electrical pulse signal and sends it to the host computer 803 together with the fnirs detection data. The synchronization time stamp records the precise time information of data acquisition, which is of great significance for GA removal processing. Because the generation of gradient artifacts may be related to specific time points or time periods during the detection process, such as synchronously occurring with a specific pulse sequence of the MRI scan. The host computer 803 can use the synchronization time stamp to perform correlation analysis of the data with the time information, more accurately identify and locate the gradient artifacts, and thus adopt a more targeted method for removal, improving the effect and accuracy of artifact removal.

[0090] In each of the above embodiments, the processor may be a processing device including more than one general-purpose processing device, 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 running other instruction sets, or a processor running a combination of instruction sets. The processor may also be more than one dedicated processing device, 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.

[0091] This application describes various operations or functions, which may be implemented as software code or instructions or defined as software code or instructions. Such content may be source code that can be directly executed or differential code (“incremental” or “patch” code) (“object” or “executable” form). The software code or instructions may be stored in a computer-readable storage medium, and when executed, may cause a machine to perform the described functions or operations, and include any mechanism for storing information in a form accessible by a machine (e.g., a computing device, an electronic system, etc.), such as a recordable or non-recordable medium (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage medium, optical storage medium, flash device, etc.).

[0092] In addition, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on this application having equivalent elements, modifications, omissions, combinations (e.g., solutions that cross various embodiments), adaptations, or alterations. The elements in the claims will be broadly interpreted based on the language employed in the claims and are not limited to the examples described in this specification or during the implementation of this application, and the examples will be construed as non-exclusive. Therefore, this specification and the examples are intended to be considered only as examples, and the true scope and spirit are indicated by the full scope of the following claims and their equivalents.

[0093] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. For example, other embodiments may be used by those of ordinary skill in the art upon reading the above description. Additionally, in the above detailed description, various features may be grouped together to simplify the present application. This should not be construed as an intention that a disclosed feature not claimed is necessary for any claim. On the contrary, the subject matter of the present application may be less than all of the features of a particular disclosed embodiment. Thus, the claims are hereby incorporated into the detailed description by way of example or embodiment, where each claim stands on its own as a separate embodiment, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations. The scope of the present application should be determined with reference to the appended claims and the full scope of equivalents to which such claims are entitled.

[0094] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions within the essence and protection scope of the present application, and such modifications or equivalent substitutions should also be regarded as falling within the protection scope of the present application.

Claims

1. An fnirs mainframe for collaborative use with an MRI imaging system, characterized in that, The fnirs host is suitable for being placed within a predetermined peripheral space range of the isocenter in a scanning bore of an MRI imaging system, and the fnirs host specifically includes: A communication interface is configured to be communicatively connected to a host computer in a control room in a wired manner without introducing ferromagnetic materials, so as to transmit fnirs detection data thereto; A shielding shell, which is made of a first non-ferromagnetic metal, wherein the shielding shell contains: A group of APD devices, each APD device is respectively configured to be connected to a corresponding D probe on a head cap 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 is made of a non-ferromagnetic material, and the metal used for the pin or plating of each APD device is a second non-ferromagnetic metal; A main processor and a processing circuit configured to be electrically connected to a group of said APD devices to process said electrical signals to obtain fnirs detection data, wherein the metal used in said electrical devices and electrical connection lines is a third non-ferromagnetic metal; and A light source unit that transmits near-infrared light to the corresponding S probe on the head cap via a second optical fiber bundle, or a driving unit that is connected to each near-infrared LED at the corresponding S probe on the head cap via electric wires to make it emit near-infrared light, the light source unit or the driving unit operates under the control of the main processor and the processing circuit, and neither the light source unit nor the driving unit contains ferromagnetic material.

2. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 1, characterized in that, The communication interface is connected to the host computer in the control room via wires or optical fibers to transmit fnirs detection data.

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

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

5. The fnirs main unit for use in cooperation with an MRI imaging system according to claim 1 or 2, characterized in that, The fnirs host is equipped with a secondary battery.

6. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 1 or 2, wherein The light source part adopts a group of near-infrared LED devices.

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

8. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 1 or 2, characterized in that, The second non-ferromagnetic metal and the third non-ferromagnetic metal are copper.

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

10. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 1, wherein It also includes an electrical harness interface and an optical fiber bundle interface; each near-infrared LED at the corresponding S probe on the head cap is connected with an electrical wire to form an electrical harness, and the electrical harness interface is used to detachably plug in the electrical harness; the optical fiber bundle interface is used to detachably plug in the first optical fiber bundle and / or the second optical fiber bundle.

11. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 10, wherein, The processing circuit further comprises: The electrostatic discharge protection unit is configured to prevent electrostatic hazards caused by the plugging and unplugging of the wire harness.

12. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 1, wherein, The shielding housing has a first dimension with a first size, a second dimension with a second size, and a third dimension with a third size, wherein the first size is smaller than the second size, and the second size is smaller than the third size.

13. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 1, wherein, It further includes a memory for backing up all the acquired data.

14. The fnirs mainframe for use in conjunction with an MRI imaging system according to claim 13, wherein, An alignment identifier is stored in the corresponding field of the memory, and the alignment identifier indicates whether the fnirs host has performed time alignment with the upper computer before the scan starts; When the fnirs host is powered on and starts up, it determines whether it has performed time alignment with the upper computer through the alignment identifier.

15. A fnirs system for use in conjunction with an MRI imaging system, characterized in that, It includes a headcap for installing the probe, a fnirs host for collaborative use with the MRI imaging system as described in any one of claims 1 to 14, a control system in the machine room, and an upper computer in the control room, and the MRI imaging system includes a scan hole.

16. The fnirs system for use in conjunction with an MRI imaging system according to claim 15, wherein, A near-infrared LED is installed at the S probe on the headcap, and the near-infrared LED is connected to the fnirs host via a wire, and the near-infrared LED does not contain ferromagnetic materials, and the length of the wire is less than 2.5 meters.

17. The fnirs system for use in conjunction with an MRI imaging system according to claim 15, wherein, The D probe on the headcap 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.

18. The fnirs system for use in conjunction with an MRI imaging system according to claim 15, wherein, The S probe on the headcap 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.

19. The fnirs system for use in conjunction with an MRI imaging system according to claim 15, wherein The control system sends an optical synchronous trigger clock signal of the MRI scan sequence, which is transmitted to the fnirs host via a high-speed serial interface and an optical fiber, and the fnirs host converts the optical synchronous trigger clock signal into an electrical pulse and transmits it to the main processor and the processing circuit.

20. The fnirs system for use in conjunction with an MRI imaging system according to claim 15, wherein The upper computer is configured to perform gradient artifact removal processing on the received fnirs detection data.

21. The fnirs system for use in conjunction with an MRI imaging system according to claim 20, wherein, The gradient artifact removal processing adopts at least one of the adaptive averaging method, the denoising autoencoder, the deep learning network, and LOGDAE.

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