Controllable visual stimulation system for magnetic resonance environment

Abstract

The invention discloses a controllable visual stimulation system for a magnetic resonance environment. The system comprises a controllable stimulation source module, a magnetic compatible display module, a magnetic resonance imaging module and a data processing module, the controllable stimulation source module generates dynamic visual stimulation patterns through the computer control system and the projector, the dynamic visual stimulation patterns are projected to the display screen made of non-magnetic materials, and then various visual stimulation modes including plane images, stereo images and unshielded binocular independent visual stimulation are achieved through the cylindrical lens grating by means of optical refraction and parallax principles. The magnetic resonance imaging module is used for synchronously collecting brain imaging data in the experiment process, and the visual stimulation signals and the imaging data are stored and analyzed in real time through the data processing module. According to the invention, the binocular vision principle of the cylindrical lens grating is utilized, accurate vision input in a complex vision stimulation scene is realized, meanwhile, the problem of magnetic field interference of traditional display equipment in a magnetic resonance environment is avoided, and the imaging quality and the experiment safety are ensured.

Description

Technical Field

[0001] This invention relates to the fields of neuroscience and medical imaging, and more specifically to a controllable visual stimulation system for use in a magnetic resonance environment. Background Technology

[0002] Magnetic resonance imaging (MRI) is widely used in neuroscience research to detect brain activity. This technology helps scientists delve into the structure and function of the brain, revealing the connections between neural activity and behavior and cognition. In neuroscience research, visual stimulation is one of the important sources of external signals and is often used to study how the brain processes and responds to different types of visual information. This type of research helps to reveal the interaction between visual perception, cognitive function, and neurons, especially when performed simultaneously with MRI, allowing for more precise analysis of the brain's neural responses and activation patterns of functional areas in response to visual stimulation.

[0003] However, conducting synchronized visual stimulation in a magnetic resonance imaging (MRI) environment presents technical challenges. Traditional visual stimulation devices (such as LCD displays) contain metal components and electronic components that generate magnetic interference in high-intensity magnetic fields. This not only affects image quality but also poses significant safety hazards, threatening both personal and equipment safety, thus rendering them unusable in an MRI environment. Furthermore, most display-based visual stimulation devices offer limited stimulation modes, failing to provide diverse visual input and thus unable to meet the diverse visual stimulation needs of complex neuroscience and clinical trials, such as stereoscopic vision and independent binocular stimulation.

[0004] For example, patent application CN106901739A discloses a virtual reality stimulation device for functional magnetic resonance imaging (fMRI), including a virtual visual presentation component, an auditory presentation component, a motion detection feedback component, and a motion control component. Specifically, the virtual visual presentation component includes an eye mask frame and a left and right presentation component disposed within the eye mask frame. The left and right presentation components each include an OLED screen for displaying virtual visual stimulation images and a VR eyepiece disposed in front of the OLED screen. Patent application CN101658419A discloses a projection system for a magnetic resonance imaging (MRI) system. This projection system includes a projector, a reflector, an image transmission fiber optic cable, a projection screen, and a head coil reflector. The projector is connected to the image transmission fiber optic cable and projects image information onto the projection screen. The image on the projection screen is reflected by the head coil reflector, allowing the patient being examined to see the image on the projection screen.

[0005] To more accurately study the brain's response to different visual stimuli, developing a magnetically compatible visual stimulation system that can operate safely in a magnetic resonance imaging (MRI) environment and provide multiple stimulation modes is of significant scientific and clinical importance. This will not only advance research in brain functional imaging but also provide more precise neurological function assessments in clinical diagnosis and treatment. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a controllable visual stimulation system and method suitable for magnetic resonance imaging (MRI) environments. This system achieves safe visual stimulation through magnetic compatibility design and supports multiple stimulation modes to adapt to different experimental needs. This invention utilizes a cylindrical lens grating and a projection system to generate visual stimulation patterns. The cylindrical lens grating is made of a transparent, non-magnetic material and possesses specific optical properties: it has a focusing function in the horizontal direction, precisely guiding the displayed image to the viewer's left and right eyes to create diverse visual stimulation effects, while maintaining a constant light path in the vertical direction. Through this structural design, the system achieves three modes: planar image visual stimulation, stereoscopic image visual stimulation, and unobstructed binocular independent visual stimulation. These modes utilize the principles of optical refraction and parallax to accurately present two-dimensional images, three-dimensional stereoscopic images, or binocular independent images, respectively, adapting to various visual stimulation scenarios. While achieving multiple visual stimuli, this invention employs a magnetic compatibility system design to avoid the magnetic interference problems of metallic materials in traditional display devices, enabling the safe and effective generation of dynamic visual stimulation in MRI environments while ensuring the magnetic compatibility and imaging quality of the imaging system.

[0007] This invention is achieved through the following technical solution: This invention provides a system and method for controllable visual stimulation in a magnetic resonance environment. The system includes a controllable stimulus source module, a magnetically compatible display module, a magnetic resonance imaging module, and a data processing module. The controllable stimulus module includes a computer control system and a projector; The computer control system is used to dynamically generate visual stimulus patterns and transmit them to the projector; The projector receives image information from the computer control system as a visual stimulus source and projects the visual stimulus information onto the display screen.

[0008] The controllable stimulus source module generates dynamic visual stimulus patterns through a computer control system and projector, projecting them onto a display screen made of non-magnetic material. Then, through a cylindrical lens grating, various visual stimulus modes are achieved using optical refraction and parallax principles, including planar images, stereoscopic images, and unobstructed binocular independent visual stimulation. The magnetic resonance imaging module is used to simultaneously acquire brain imaging data during the experiment, and the data processing module performs real-time storage and analysis of the visual stimulus signals and imaging data.

[0009] Furthermore, the controllable stimulus source module should be located at a safe distance from the magnetic resonance imaging module. As one possible implementation, the controllable stimulus source module is installed outside the magnetic resonance chamber, and the projector's output window should be fixed to the wall of the magnetic resonance chamber to prevent the strong magnetic field generated during the operation of the magnetic resonance imaging module from affecting the computer control system and the projector's metal components.

[0010] The magnetically compatible display module includes a display screen and a cylindrical lens grating.

[0011] The display screen is a transparent screen made of non-magnetic material, used to receive images projected by a projector.

[0012] The cylindrical lens grating is made of transparent, non-magnetic material. The side closest to the display screen is flat, while the other side consists of semi-cylindrical lenses with identical structures arranged periodically in the horizontal direction. The cylindrical lens grating focuses in the horizontal direction perpendicular to the cylindrical axis, but does not focus in the vertical direction parallel to the cylindrical axis. In other words, it acts as a converging lens in the horizontal direction and does not alter the path of light in the vertical direction.

[0013] Furthermore, the focal plane of the cylindrical lens grating coincides with the display screen.

[0014] As one possible implementation, the cylindrical lens grating has the following properties: the radius of curvature r of the semi-cylindrical surface of the cylindrical lens, the refractive index n of the cylindrical lens material, the thickness d of the cylindrical lens, and the grating pitch p. The sub-pixel spacing t of the display screen, the distance s between the display screen and the cylindrical lens grating, the horizontal distance D between the experimental subject or patient and the apex of the semi-cylindrical surface of the cylindrical lens (i.e., viewing distance), and the interocular distance e of the experimental subject or patient.

[0015] As one possible implementation, based on optical refraction and geometric properties, the properties of the cylindrical lens grating, the display screen, and the spatial relationship between the experimental subject or patient satisfy... cylindrical lens thickness , grid pitch Where m is the number of viewpoints. As one possible implementation, for both binocular independent visual stimulation and binocular stereoscopic visual stimulation, the number of viewpoints m can be set to 2.

[0016] By projecting image information onto the display screen through the controllable stimulus source module, experimental subjects or patients can see that these pixels form a complete image at that location, thus achieving visual stimulation.

[0017] Furthermore, the controllable stimulus source module controls the display screen to display the left-eye image on a portion of its sub-pixels and the right-eye image on another portion of its sub-pixels. Utilizing the refraction effect of the cylindrical lens grating, light is guided into a specific observation area. Specifically, under the refraction of the lens on the cylindrical lens grating, the light emitted from the left and right eye sub-pixels is deflected after passing through the grating. Light from the left-eye pixel enters the viewer's left eye, and light from the right-eye pixel enters the viewer's right eye, achieving unobstructed independent binocular visual stimulation.

[0018] Furthermore, the controllable stimulus source module encodes the pixels of the display screen to generate stereoscopic image pairs corresponding to the left and right eyes. The controllable stimulus source module and the magnetically compatible display module project the stereoscopic image pairs of the left and right eyes onto the left and right sub-pixels of the display screen, respectively. The light from the left eye pixel enters the viewer's left eye, and the light from the right eye pixel enters the viewer's right eye. Under the fusion of the brain, stereoscopic vision is generated, thereby stimulating the binocular stereoscopic vision of the experimental subjects or patients.

[0019] The magnetic resonance imaging module includes a magnetic resonance imaging machine.

[0020] The magnetic resonance imaging (MRI) machine includes a main magnet, a shimming coil, a gradient coil, a radio frequency (RF) coil, and a computer system. The RF coil employs a transmitting coil and a receiving coil, wherein the receiving coil is a wearable head-mounted coil that does not obstruct the eyes of the test subject or patient. Alternatively, the RF coil can be a wearable head-mounted coil integrating transmitting and receiving functions.

[0021] The data processing module stores, processes, and analyzes visual stimulus signals and magnetic resonance imaging image data in real time.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a magnetically compatible visual stimulus generation scheme that enables simultaneous stimulation and imaging detection in a magnetic resonance environment. By using a projector and display screen instead of a traditional electronic display screen to generate visual stimuli, it avoids the abnormalities or image quality issues that can occur with the metal materials in electronic display screens under magnetic field conditions.

[0023] Furthermore, the present invention employs a cylindrical lens grating, which can realize the functions of planar image visual stimulation, stereoscopic image visual stimulation, and unobstructed binocular individual visual stimulation, covering a variety of visual stimulation scenarios. Moreover, the device is simple and can be dynamically controlled. Attached Figure Description

[0024] Figure 1 This is the overall intent of the system of the present invention; Figure 2 This is a schematic diagram of the system structure of the present invention; Figure 3This refers to the spatial relationship between the magnetically compatible display module and the experimental subject or patient in the system of this invention; Figure 4 This is a pixel arrangement diagram of the display screen for implementing the visual stimulation method of the present invention. Detailed Implementation

[0025] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the invention is not limited to the specific embodiments disclosed below.

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] Example 1: A controllable system for magnetic resonance visual stimulation, such as Figure 1 As shown, it includes a controllable stimulus source module 100, a magnetically compatible display module 200, a magnetic resonance imaging module 300, and a data processing module 400.

[0028] In one embodiment, such as Figure 2 As shown, a specific controllable system for magnetic resonance visual stimulation is provided, including a computer control system 1, a projector 2, a magnetic resonance observation chamber wall 3, a display screen 4, a cylindrical lens grating 5, the head of the experimental subject or patient 6, the right eye 7, the left eye 8, a wearable head coil 9, and a magnetic resonance imaging machine 10.

[0029] Computer control system 1 generates and transmits visual stimulus patterns, which are then sent to projector 2. Both computer control system 1 and projector 2 are mounted outside the wall 3 of the magnetic resonance observation chamber and are magnetically shielded to avoid interference from the magnetic resonance environment. Projector 2 projects image information onto display screen 4, which is used to display the visual stimulus patterns and is made of a non-magnetic transparent material.

[0030] The cylindrical lens grating 5 is located behind the display screen 4 and is made of transparent, non-magnetic material. One side of it is flat, and the other side consists of semi-cylindrical lenses arranged periodically in the horizontal direction. The spatial structure is shown in the attached figure. Figure 2 As shown in the diagram, the cylindrical lens grating 5 has a focusing function in the horizontal direction, while not changing the light propagation path in the vertical direction. It should be noted that the material of the cylindrical lens grating includes, but is not limited to, polycarbonate, acrylic resin, and other optically transparent non-magnetic materials.

[0031] The cylindrical lens grating 5 is made of a transparent, non-magnetic material. The side closest to the display screen is flat, while the other side consists of a series of identical semi-cylindrical lenses arranged periodically in the horizontal direction. The cylindrical lens grating 5 focuses in the horizontal direction perpendicular to the cylindrical axis, but does not focus in the vertical direction parallel to the cylindrical axis. In other words, it acts as a converging lens in the horizontal direction and does not alter the path of light in the vertical direction. The focal plane of the cylindrical lens grating coincides with the display screen.

[0032] The right eye 7 and left eye 8 of the test subject or patient's head 6 are oriented towards the cylindrical lens grating 5, with the horizontal direction of both eyes aligned with the periodic repetition direction of the cylindrical lens grating 5. The test subject or patient's head 6 is fitted with a wearable head coil 9. The wearable head coil 9 ensures that both eyes of the test subject or patient are unobstructed, guaranteeing uninterrupted visual stimulation and image formation.

[0033] The magnetic resonance imaging (MRI) machine 10 includes a main magnet, shimming coils, gradient coils, and radio frequency coils. MRI is used to acquire brain imaging data in real time and can be performed synchronously with visual stimulation.

[0034] The data processing module stores and analyzes visual stimulus signals and magnetic resonance imaging data in real time.

[0035] As one specific implementation method, such as Figure 3 As shown, the cylindrical lens grating 5 has the following optical and geometric properties: the radius of curvature r of the semi-cylindrical surface of the cylindrical lens, the refractive index n of the cylindrical lens material, the thickness d of the cylindrical lens, and the grating pitch p of the cylindrical lens. The sub-pixel spacing t of the display screen 4, and the distance s between the display screen 4 and the cylindrical lens grating 5. The horizontal distance D between the binoculars 7 and 8 of the experimental subject or patient 6 and the apex of the semi-cylindrical surface of the cylindrical lens (i.e., viewing distance), and the interocular distance e of the experimental subject or patient.

[0036] As one specific implementation, based on optical refraction and geometric properties, the properties of the cylindrical lens grating 5, the display screen 4, and the spatial relationship between the experimental subject or patient 6 satisfy... cylindrical lens thickness , grid pitch Where m is the number of viewpoints. For binocular independent visual stimulation and binocular stereoscopic visual stimulation, the number of viewpoints m can be 2.

[0037] Compared to existing technologies, this embodiment uses magnetically compatible non-magnetic material optical elements and display modules, and installs the controllable stimulation source module 100 and data processing module 400 outside the magnetic resonance observation room. This can effectively avoid electromagnetic field interference problems that may be generated by metal devices in a magnetic environment, and realize safe and effective visual stimulation in a magnetically compatible environment. It can simultaneously acquire magnetic resonance brain imaging data when visual stimulation is applied, and collaboratively analyze the neural response of various brain regions to visual stimulation.

[0038] Example 2: A controllable method for magnetic resonance visual stimulation.

[0039] In this embodiment, the visual stimulation is implemented in three modes: planar image visual stimulation, stereoscopic image visual stimulation, and unobstructed binocular independent visual stimulation. In these modes, the computer control system generates different image content as needed, and through the coordinated action of the display screen and the cylindrical lens grating, ensures that light is accurately transmitted to the visual field of the experimental subject or patient.

[0040] The pixels on the display screen are divided into two groups: left eye pixels (41) and right eye pixels (42), arranged alternately horizontally. Pixels in the same column vertically belong to the same group. Figure 4 As shown. The horizontal direction is consistent with the horizontal direction of the eyes of the test subject or patient.

[0041] In the planar image visual stimulation mode, the computer control system generates a two-dimensional image and projects the image information onto a display screen. Left-eye pixel 41 and right-eye pixel 42 on the display screen are encoded with specific image content; each pair of adjacent left and right-eye pixels corresponds to the same pixel in the two-dimensional image. When the image passes through a cylindrical lens grating, the light is focused horizontally and guided to the eyes of the test subject or patient, ensuring that both eyes receive the same two-dimensional image. This mode is simple and direct, suitable for routine visual stimulation.

[0042] In the stereoscopic visual stimulation mode, the computer control system alternately encodes pre-captured or virtually generated left and right eye images with parallax in the horizontal direction and projects these images onto the left-eye pixel group 41 and right-eye pixel group 42 on the display screen. When the images pass through the cylindrical lens grating, due to the horizontal refraction of the grating, the light emitted by the left and right eye pixels is guided to the observer's left and right eyes respectively. Because the left and right eyes receive different image information and fuse it in the brain, the experimental subjects or patients experience a precise stereoscopic visual effect.

[0043] Magnetic resonance imaging (MRI) machines can perform brain imaging while the test subject or patient receives stereoscopic visual stimulation, recording and studying the responses of different brain regions to stereoscopic visual stimulation.

[0044] In the unobstructed binocular independent visual stimulation mode, the computer control system generates completely independent image visual stimuli for each eye, performs alternating horizontal encoding, and projects this image information onto the left-eye pixel group 41 and the right-eye pixel group 42 on the display screen. When the image passes through the lenticular grating, due to the horizontal refraction of the lenticular grating, light from the left-eye pixel 41 only enters the left eye, and light from the right-eye pixel 42 only enters the right eye. This ensures that each eye receives an independent image without overlap or interference. This mode is suitable for experimental scenarios requiring different stimuli for the left and right eyes to test the independent response of binocular vision. Specifically, the computer control system can load only the left-eye pixel group 41 corresponding to the left-eye image or the right-eye pixel group 42 corresponding to the right-eye image, without loading the other group of pixels. This achieves unobstructed monocular visual stimulation, while the other eye does not receive visual stimulus signals from the display screen, eliminating the need for additional occlusion and avoiding the impact of occlusion on neural activity.

[0045] Magnetic resonance imaging (MRI) machines can perform brain imaging while the test subject or patient receives independent visual stimulation from both eyes. They can record and study the responses of different brain regions to visual stimulation from the left and right eyes, as well as the brain responses to different visual stimuli received by both eyes.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A controllable visual stimulation system for use in a magnetic resonance environment, characterized in that, include: It can control the stimulus source module, the magnetically compatible display module, the magnetic resonance imaging module, and the data processing module; The controllable stimulus module includes a computer control system and a projector; The computer control system is used to dynamically generate visual stimulus patterns and transmit them to the projector; The projector receives image information from the computer control system as a visual stimulus source and projects the visual stimulus information onto the magnetically compatible display module. The magnetic resonance imaging module is used to synchronously acquire brain imaging data during the experiment, and the data processing module stores and analyzes the visual stimulus signals and imaging data in real time.

2. The controllable visual stimulation system according to claim 1, characterized in that, The controllable stimulus source module is positioned at a safe distance from the magnetic resonance imaging module.

3. The controllable visual stimulation system according to claim 2, characterized in that, The controllable stimulus source module is installed outside the magnetic resonance chamber, and the projector's output window is located on the wall of the magnetic resonance chamber.

4. The controllable visual stimulation system according to claim 1, characterized in that, The magnetically compatible display module includes a display screen and a cylindrical lens grating.

5. The controllable visual stimulation system according to claim 4, characterized in that, The display screen is a transparent screen made of non-magnetic material, used to receive images projected by the projector; the cylindrical lens grating is made of transparent non-magnetic material, with one side near the display screen being flat, and the other side consisting of semi-cylindrical lenses with the same structure arranged periodically in the horizontal direction.

6. The controllable visual stimulation system according to claim 5, characterized in that, The cylindrical lens grating is focused in the horizontal direction perpendicular to the cylindrical axis and not focused in the vertical direction parallel to the cylindrical axis; the focal plane of the cylindrical lens grating coincides with the display screen.

7. The controllable visual stimulation system according to claim 4, characterized in that, The controllable stimulus source module controls the display screen to display the left eye image in a portion of its sub-pixels and the right eye image in another portion of its sub-pixels. By utilizing the refraction effect of the cylindrical lens grating, light is guided into a specific observation area. That is, under the refraction effect of the lens on the cylindrical lens grating, the light emitted from the left and right eye sub-pixels is deflected after passing through the cylindrical lens grating. The light from the left eye pixel enters the viewer's left eye, and the light from the right eye pixel enters the viewer's right eye, thus achieving unobstructed binocular independent visual stimulation.

8. The controllable visual stimulation system according to claim 4, characterized in that, The controllable stimulus source module encodes the pixels of the display screen to generate stereoscopic image pairs corresponding to the left and right eyes. The controllable stimulus source module and the magnetically compatible display module project the stereoscopic image pairs of the left and right eyes onto the left and right sub-pixels of the display screen, respectively. The light from the left eye pixel enters the viewer's left eye, and the light from the right eye pixel enters the viewer's right eye. Under the fusion of the brain, stereoscopic vision is generated, realizing the binocular stereoscopic vision stimulation of the experimental subjects or patients.

9. The controllable visual stimulation system according to claim 1, characterized in that, The magnetic resonance imaging module includes a magnetic resonance imaging machine; The magnetic resonance imaging machine includes a main magnet, a shimming coil, a gradient coil, a radio frequency coil, and a computer; the radio frequency coil uses a transmitting coil and a receiving coil, wherein the receiving coil is a wearable head coil and does not obstruct the eyes of the experimental subject or patient; the radio frequency coil is a wearable head coil that integrates transmitting and receiving.

10. The controllable visual stimulation system according to claim 1, characterized in that, The data processing module stores, processes, and analyzes visual stimulus signals and magnetic resonance imaging image data in real time.

Images