Device for adjusting virtual visual target distance of portable nystagmus view instrument

Abstract

The utility model discloses a portable nystagmus view instrument virtual visual target distance adjusting device comprising the following structures: a display module group, the inner side of which is rotatably provided with a first thrust cam; the lens group A and the lens group B are arranged on a visual window on the inner side of the display module and located on the two sides of the first thrust cam respectively, meanwhile, a distance measuring sensor A and a distance measuring sensor B are installed on the lens group A and the lens group B respectively, and the signal output end of the distance measuring sensor A and the signal output end of the distance measuring sensor B are connected with external display interaction equipment; the hand-shifting roller b is rotatably mounted on the side wall of the view end of the shell; the driven gear is rotatably mounted on the side wall of the view end of the shell and is meshed with the teeth on the hand-shifting roller b; the second thrust cam is mounted in the center of the driven gear, and the driven gear can drive the second thrust cam to rotate together when rotating; wherein the inner side of the display module corresponds to the visual field end of the shell, and the display module is fixedly installed on the visual field end of the shell.

Description

Technical Field

[0001] The utility model relates to the technical field of nystagmus imaging instruments, in particular to a device for adjusting the distance of a virtual visual target of a portable nystagmus imaging instrument. Background Art

[0002] A portable nystagmography device is a head-mounted mask that can be worn directly on the head for a quick and convenient nystagmography examination. The visual target is located inside the device, directly in front of the subject's eyes, and displays calibration and stimulation content in a specific manner. Typically, this is an LED light that flickers at a specific frequency. Because the LED is fixed to the motherboard and cannot be moved, its distance from the subject's eyes is fixed. Therefore, it is affected by factors such as the subject's head shape, forehead width, facial flatness, and eye concavity. The actual distance from the built-in visual target of this portable nystagmography device to the subject's eyes is generally between 4 and 6 cm, which is much smaller than the required distance from the visual target to the subject's eyes in the aforementioned nystagmography examination. This will, to a certain extent, affect the credibility and accuracy of the examination results. Utility Model Content

[0003] In view of the above technical problems, the utility model provides a device for adjusting the distance of a virtual viewing target in a portable nystagmus imager.

[0004] In order to achieve the above-mentioned purpose, the technical solution of the present utility model is as follows:

[0005] A device for adjusting the distance of a virtual visual target in a portable nystagmography apparatus comprises:

[0006] A display module, wherein a first thrust cam is rotatably disposed inside the display module;

[0007] Lens group A and lens group B are arranged on the viewing window inside the display module and are located on both sides of the first thrust cam. At the same time, distance sensors A and B are respectively installed on them, and the signal output ends of distance sensors A and B are connected to the external display interaction device;

[0008] The hand-operated roller b is rotatably mounted on the side wall of the housing at the viewing end;

[0009] The driven gear is rotatably mounted on the side wall of the housing at the viewing end and meshes with the teeth on the hand-operated roller b;

[0010] The second thrust cam is installed at the center of the driven gear, and when the driven gear rotates, it can drive the second thrust cam to rotate together;

[0011] The inner side of the display module corresponds to the visual end of the housing, and the display module is fixedly mounted on the visual end of the housing. At this time, the first thrust cam and the second thrust cam are in corresponding contact with each other.

[0012] The hand-operated roller b is rotatably mounted on the side wall of the housing at the viewing end via a damping pad and a roller positioning screw.

[0013] The two sides of the display module are respectively connected to the two high platform nut columns on the viewing end of the shell through module limiting screws A and module limiting screws B and module telescopic springs A and module telescopic springs B respectively mounted on the module limiting screws A and module limiting screws B.

[0014] The beneficial effects of the utility model are:

[0015] 1. The present invention solves the problem that the distance between the visual target of a portable nystagmus analyzer and the subject's eyes is too close to meet the prescribed distance range. By utilizing virtual reality technology to replace the traditional visual target with a virtual visual target, the virtual image equivalent distance can meet the prescribed distance requirement. This ensures that the distance between the visual target and the subject's eyes meets the prescribed range within the narrow space inside the portable nystagmus analyzer. This makes the visual target calibration and the presented stimulation content effective and reliable for the subject, and also greatly improves the convenience and speed of nystagmus examination.

[0016] 2. This utility model solves the problem of the fixed and unadjustable position of the visual target in portable nystagmography. By utilizing a roller linkage, a cam bidirectional spiral push angle, a platform nut column, and a telescopic spring to form a composite linkage device, the horizontal forward and backward movement of the display module (visual target) can be manually and quantitatively adjusted. The adjusted distance is limited by the damping principle. This effectively solves the problem of large variations in the virtual distance from the visual target to the eye during near-eye display, which is affected by factors such as the subject's head shape, forehead width, facial flatness, eye concavity, and the wearing of the portable nystagmography device.

[0017] 3. The present invention incorporates a distance sensor on the lens assembly of the display module's viewing window to measure the distance from the viewing target (display module + lens assembly) to the eye. This sensor displays the actual distance from the viewing target to the eye and the virtual image equivalent distance calculated by the system in real time. When the viewing target (display module + lens assembly) is adjusted and moved, the displayed distance value changes accordingly. Furthermore, the present invention uses a standard value for the virtual image equivalent distance, calculated under ideal conditions, as a reference for calibrating and verifying the adjusted distance value. In actual use, due to factors such as instrument wear, the distance value adjusted by the user may deviate from the actual distance adjusted by proper wear. When the deviation is within a reasonable range, the value is considered valid. However, if the deviation is significant, it should be considered that the portable nystagmography device is not properly worn or is malfunctioning. This design ensures that the distance from the viewing target to the subject's eye is accurate and valid during examinations using the portable nystagmography device. This design significantly reduces the risk of undesirable deviations in the distance from the viewing target to the subject's eye caused by wear or other objective factors, thereby improving the accuracy and reliability of the examination results.

[0018] 4. Double spiral push angles are used to control the forward and backward movement of the sight target. The contact area and force-bearing area between the two spiral push angles are large, and they are always in a spiral linkage state, which can ensure the stability of the sight target during movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 It is a three-dimensional diagram of the utility model;

[0021] Figure 2 It is an exploded view of the utility model;

[0022] Figure 3 It is a three-dimensional diagram of the display module of the present utility model;

[0023] Figure 4 This is a connection diagram of the second thrust cam of the utility model;

[0024] Figure 5 It is a working principle diagram of the utility model;

[0025] Figure 6 It is a schematic diagram of a model of the present utility model;

[0026] Figure 7 It is a schematic diagram of the model principle of the present utility model. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. Furthermore, descriptions of known structures and technologies are omitted in the following description to avoid unnecessary confusion regarding the concepts of the present invention.

[0028] like Figures 1 to 4 As shown, a portable nystagmography device for adjusting the distance of a virtual visual target includes: a display module 1405, on the inner side of which a first thrust cam 1414 is rotatably provided; a lens group A1410 and a lens group B1411 are provided on the viewing window inside the display module 1405 and are located on both sides of the first thrust cam 1414, and are respectively mounted with a distance sensor A1412 and a distance sensor B1413, and the signal output ends of the distance sensor A1412 and the distance sensor B1413 are connected to an external display interaction device; a hand-operated scroll wheel b1401 is rotatable The display module 1405 is mounted on the side wall of the housing 8 at the viewing end; the driven gear 1404 is rotatably mounted on the side wall of the housing 8 at the viewing end and meshes with the teeth on the hand-moving roller b1401; the second thrust cam 1415 is mounted at the center of the driven gear 1404, and when the driven gear 1404 rotates, it can drive the second thrust cam 1415 to rotate together; wherein, the inner side of the display module 1405 corresponds to the viewing end of the housing 8, and the display module 1405 is fixedly mounted on the viewing end of the housing 8. At this time, the first thrust cam 1414 and the second thrust cam 1415 are in contact with each other. The hand-moving roller b1401 is rotatably mounted on the side wall of the housing 8 at the viewing end via the damping pad 1403 and the roller positioning screw 1402. The two sides of the display module 1405 are respectively connected to the two high platform nut columns 1416 on the viewing end of the shell 8 through the module limit screws A1409 and the module limit screws B1408 and the module telescopic springs A1406 and the module telescopic springs B1407 respectively mounted on the module limit screws A1409 and the module limit screws B1408.

[0029] Here’s how it works:

[0030] ① Display module 1405 has two display screens, each corresponding to a viewing window. Lens group A 1410 and lens group B 1411 are mounted outside the viewing windows. The two display screens on display module 1405 are within the focal point of the corresponding lens groups. When calibration content or stimulation content is displayed or played on the screen, it is refracted by the lens groups to generate a magnified erect virtual image. After the content displayed on the screen is refracted by the optical system of the lens groups, the resulting virtual image has an imaging distance of between 0.5 and 2 meters, meaning that the virtual image is equivalently positioned between 0.5 and 2 meters from the subject's eye.

[0031] ② Distance measuring sensors A1412 and B1413 are installed in the center above lens group A1410 and lens group B1411. When the subject wears the portable nystagmography device and turns it on, distance measuring sensors A1412 and B1413 begin to work, and the flexible screen 13 of the portable nystagmography device can display the actual distance between the subject's eyes and the lens group and the virtual image equivalent distance converted by the system;

[0032] ③ When the displayed virtual image equivalent distance is not within the specified distance range from the eye to the visual target (exceeds or is less than), the distance between the utility model and the subject's eye can be manually adjusted to meet the specified required range; the specific adjustment principle and method are as follows:

[0033] A. The manual dial roller b1401 and its linked driven gear 1404 are aligned during assembly. After this alignment, the helical angle of the second thrust cam 1415 and the helical angle of the first thrust cam 1414, which are assembled as required, are in the lowest position. At this point, the dial number displayed on the manual dial roller b1401 is 0, representing the display module 1405, or the visual target, which is closest to the subject's eyes.

[0034] B. Turn the hand wheel b1401 counterclockwise. The distance between the display module 1405 and the subject's eyes will increase. The working principle is as follows:

[0035] a. After aligning and assembling the hand-operated roller b1401, the second thrust cam 1415, and the first thrust cam 1414 according to step ①, the display module will be in the lowest position. At this time, rotate the hand-operated roller b1401 counterclockwise, which will drive the second thrust cam 1415 below to rotate counterclockwise. The spiral push angle on the second thrust cam 1415 will rotate the corresponding spiral push angle of the first thrust cam 1414 from the lowest position to the highest position, and the distance between the display module 1405 and the subject's eyes will gradually increase.

[0036] b. When the combination of the spiral push angle on the second thrust cam 1415 and the spiral push angle of the first thrust cam 1414 on the display module 1405 is at the lowest position, the number on the first dial wheel is 0, and the hand dial wheel b1401 has a total of four numbers: 0, 1, 2, and 3. As the hand dial wheel b1401 is rotated counterclockwise, the numbers on the hand dial wheel b1401 will gradually increase. The flexible screen 13 of the portable nystagmography device is adjusted to the distance measurement interface. The hand dial wheel b1401 is rotated counterclockwise. The numbers on the flexible screen 13 representing the actual distance from the display module 1405 to the subject's eye and the virtual image equivalent distance will also increase in real time. Otherwise, the numbers will decrease.

[0037] C. When designing the product, it is assumed that the portable nystagmography device is correctly worn on the subject's head in accordance with the specifications, and that the subject's eyes are absolutely flat relative to the device (i.e., the ideal state is such that there is no sunken or convex eye). Based on this ideal state, the actual physical distance between the device and the eyes is calculated based on the rotation of the linkage mechanical structure to push the display module horizontally backward. The actual distance between the device and the eyes corresponding to each number on the hand-dial wheel b1401 is: number 0 = 4 cm, number 1 = 5 cm, number 2 = 6 cm, and number 3 = 7 cm. The corresponding algorithm can be used to deduce the distance based on the refractive index of the lens assembly, distance mapping, and other parameters. The virtual image equivalent distance of each actual distance is: 0 = 4cm = 0.5m, 1 = 5cm = 1m, 2 = 6cm = 1.5m, 3 = 7cm = 2m. These are the standard values ​​calculated by simulation under ideal conditions. In actual use, they will be affected by factors such as the examinee's head shape, forehead width, facial flatness, eye convexity and concavity, and the wearing of the portable nystagmus imager. The actual values ​​and the standard values ​​calculated by simulation will have more or less discrepancies. At this time, it is necessary to adjust the distance of the utility model according to the actual situation to adjust it to the distance range from the visual target to the human eye specified in the nystagmus image examination. The simulated calculation under the above ideal conditions is The standard value will be used as a reference for calibration of the adjustment range. For example, the subject wears the portable nystagmography device and turns it on, and then adjusts the interface of the flexible screen 13 to the distance measurement interface. At this time, the distance measurement sensor A1412 and the distance measurement sensor B1413 will automatically start, and automatically upload the measured distance parameters from the present invention to the subject's eyes to the system and display them on the flexible screen 13. For example, the actual distance measured is 3.72cm, and the system converts the corresponding virtual image equivalent distance to be approximately 0.43m. This value is far less than the specified distance range. At this time, it is necessary to manually increase the actual distance from the present invention to the eye by turning the hand dial wheel b1 counterclockwise. 401. When the number 1 appears on the hand-turned roller b1401, the flexible screen 13 displays the actual distance = 4.92cm and the virtual image equivalent distance = 0.93m. At this time, the standard value calculated by simulation under the ideal state is compared and referenced: the number on the hand-turned roller b1401 = 1 = actual distance 5cm = virtual image equivalent distance 1m. It can be seen that the distance value of the utility model adjusted this time is credible. Because it is affected by factors such as the flatness of the subject's face and the degree of convexity and concavity of the eyes, this error is a reasonable error. If the error is large, it means that the portable nystagmus tryer is not worn properly or has malfunctioned, and it needs to be readjusted or the instrument needs to be checked and adjusted again.

[0038] (3) The mechanical linkage relationship of target adjustment is:

[0039] ① A damping pad 1403 is mounted on the mounting nut column of the hand-moving roller b1401. The damping pad 1403 can increase the damping of the hand-moving roller b1401 so that it can remain in the limited position and not rotate after being moved;

[0040] ② The spiral push angle facing the second thrust cam 1415 is the spiral push angle of the first thrust cam 1414 on the display module 1405;

[0041] ③ Rotating the hand-dialed roller b1401 counterclockwise will drive the second thrust cam 1415 below it, and the spiral push angle of the second thrust cam 1415 will drive the spiral push angle of the first thrust cam 1414, thereby driving the entire utility model to move backward horizontally. Because there are module limit screws A1409 and module telescopic springs A1406 and module telescopic springs B1407 on the high platform nut column 1416 for installing the display module 1405, the movement of the utility model is under pushing and squeezing force, so its movement process is smooth and will not fall off or misplace. According to the above a, it can be known that the adjusted utility model will not rotate because the hand-dialed roller b1401 is damped by the damping pad 1403;

[0042] ④ In the entire structural relationship, because the spiral push angle of the second thrust cam 1415 is always in contact with the spiral push angle of the first thrust cam 1414, the thrust cam will not fall off. When the lowest point of the spiral push angle of the second thrust cam 1415 contacts the lowest point of the spiral push angle of the first thrust cam 1414, the display module 1405 is closest to the human eye, and the number on the hand-shift roller b1401 is 0 at this time. When the highest point of the spiral push angle of the second thrust cam 1415 contacts the highest point of the spiral push angle of the first thrust cam 1414, the utility model is farthest from the human eye, and the number on the hand-shift roller b1401 is 3 at this time.

[0043] Working principle and working process of the whole machine

[0044] ① The present invention uses virtual reality technology to implement the visual target function of a portable nystagmus imaging device and present a full-field stimulation effect. The principle is as follows: the present invention has two display modules 1405, each of which has a viewing window and lens group A 1410 and lens group B 1411. When the patient wears the device and adjusts the orientation and angle, a superimposed virtual reality model of "human eye - lens group - display module (visual target / screen)" is formed, as shown in the schematic diagram. Figure 5 shown.

[0045] In the present invention, the image on the display module 1405 will be refracted by the lens group A1410 and the lens group B1411 to present a 75-150 inch 16:9 virtual high-definition large screen display effect. The display size changes with the change of the distance from the visual target to the eye: the minimum is 75 inches and the maximum is 150 inches. The model diagram is shown as follows: Figure 6 and Figure 7 shown.

[0046] exist Figure 6The actual image is displayed on the physical display module A, and B is the virtual screen. The calculation model of the virtual screen pixel size is as follows:

[0047] px1= ((ppd * arctan((l1 / 2) / d1) * 2)) / ((arctan((l1 / 2) / d1) * 2 * π / 180) *(d1 / cos(fov * π / 180 / 2)))) * l1)

[0048] fov = arctan((l1 / 2) / d1) * 2

[0049] px2=ppd*fov

[0050] d2=d / cos(fov * π / 180 / 2)

[0051] l2 = (fov * π / 180) * d2

[0052] px1= (l1* px2) / l2.

[0053] exist Figure 7 In the figure, l1 is the plane physical size, d1 is the plane distance, l2 is the surface physical size, d2 is the surface distance, px1 is the plane pixel size, px2 is the surface pixel size, PPD = pixels per degree: It is an indicator to measure the clarity and realism of an image. It indicates the number of pixels corresponding to each degree of viewing angle. FOV = field of view: field of view, which indicates the angular range of images that the human eye can receive or display.

[0054] Therefore, when the patient wears the instrument, the visual target can present a full-field stimulation effect of a high-definition large screen in front of the patient's eyes.

[0055] ② The visual target of a traditional nystagmography instrument is generally a strip LED screen or a TV, projector, or display. In the nystagmography examination, there is a certain range of requirements for the distance between the subject's eyes and the visual target, specifically: 1.2-1.4 meters for a strip LED screen and 0.8-1 meter for a TV, projector, or display. Within this distance range, the visual target corresponds to a full-view stimulation of the subject without a visual blind spot, and its calibration and the presented stimulation content are more effective and reliable for the subject. The present invention adopts the linkage relationship between the hand-operated roller b1401 and the spiral push angles of the second thrust cam 1415 and the first thrust cam 1414 to realize the horizontal adjustment of the physical distance between the visual target and the subject's eyes. The movement of the physical distance will cause the corresponding movement of the virtual image equivalent distance. The mapping between the physical distance and the virtual distance is a trigonometric function relationship, and its trigonometric function model is: D_virtual=D_physical×(screen_width / eye_to_screen_distance×tan(FOV_degrees / 2) In the model, D_virtual represents the physical distance, screen_width represents the screen width, eye_to_screen_distance represents the distance between the subject's eyes and the screen, and FOV_degrees represents the field of view. The entire linkage mechanism for adjusting the viewing target in the instrument is equipped with distance sensors A1412 and B1413, which can measure the physical distance between the viewing target (screen) and the subject's eyes in real time. The screen size and the refractive index of the lens assembly are fixed parameters. Therefore, when the physical distance between the viewing target and the subject's eyes changes, the system algorithm can simultaneously calculate the corresponding change in the virtual image equivalent distance in real time, ensuring that the distance between the viewing target and the subject's eyes (the virtual image equivalent distance) is within the specified range for nystagmus examinations. To avoid errors caused by improper instrument wear or other subjective and objective reasons, the present invention has designed a standard value for the virtual image equivalent distance corresponding to the physical distance between the viewing target and the subject's eyes, calculated under ideal conditions, to calibrate and verify the adjusted distance value.

[0056] It should be understood that the above-described specific embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the scope of protection of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. A device for adjusting the distance of a virtual target using a portable nystagmography apparatus, characterized in that: include: A display module (1405) having a first thrust cam (1414) rotatably disposed on its inner side; Lens group A (1410) and lens group B (1411) are arranged on the viewing window inside the display module (1405) and are respectively located on both sides of the first thrust cam (1414). At the same time, a distance sensor A (1412) and a distance sensor B (1413) are respectively installed thereon, and the signal output ends of the distance sensor A (1412) and the distance sensor B (1413) are connected to the external display interaction device; A hand-operated roller b (1401) is rotatably mounted on the side wall of the housing (8) at the viewing end; A driven gear (1404) is rotatably mounted on the side wall of the housing (8) at the viewing end and meshes with the teeth on the hand-operated roller b (1401); A second thrust cam (1415) is mounted at the center of the driven gear (1404), and when the driven gear (1404) rotates, it can drive the second thrust cam (1415) to rotate together; The inner side of the display module (1405) corresponds to the visual field end of the housing (8), and the display module (1405) is fixedly mounted on the visual field end of the housing (8). At this time, the first thrust cam (1414) and the second thrust cam (1415) are in corresponding contact with each other.

2. The device for adjusting the virtual target distance of a portable nystagmography apparatus according to claim 1, characterized in that: The hand-operated roller b (1401) is rotatably mounted on the side wall of the viewing end of the housing (8) via a damping pad (1403) and a roller positioning screw (1402).

3. The device for adjusting the virtual target distance of a portable nystagmography apparatus according to claim 1, characterized in that: The two sides of the display module (1405) are connected to the two high platform nut columns (1416) on the viewing end of the shell (8) through the module limit screws A (1409) and the module limit screws B (1408) and the module telescopic springs A (1406) and the module telescopic springs B (1407) respectively mounted on the module limit screws A (1409) and the module limit screws B (1408).

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