Perspective inspection instrument

Abstract

Provided is a perspective inspection instrument 1 that is capable of accurately measuring a fusion maintenance capacity and that enables reduction in size and weight.　The perspective inspection instrument 1 includes a hand-held body 2. The body 2 includes: a window part 3 in which two light-transmitting members 8 and 9 are arranged to be overlapped; and a variable mechanism 11 that cooperates with the two light-transmitting members 8 and 9 to continuously vary the transmittance of light transmitted through the window part 3.

Description

Strabismus testing equipment

[0001] The present invention relates to a strabismus examination instrument.

[0002] Conventionally, strabismus testing devices with a handheld main body have been known (see, for example, Non-Patent Document 1). Non-Patent Document 1 discloses a testing device used to test the ability to maintain fusion (hereinafter referred to as "fusional maintenance ability"). The testing device disclosed in Non-Patent Document 1 has a plate-type main body with multiple windows formed in a vertical row, and filters with different light transmittances are disposed in each window. In a test using the testing device disclosed in Non-Patent Document 1, the windows are aligned with one eye of a patient with indirect exotropia, and the windows aligned with the eyes are changed in ascending order of transmittance, and the ability to maintain fusion is measured based on the transmittance of the filters when strabismus appears.

[0003] Ryota Takada and 15 others, "Evaluation of the ability to maintain heterophoria using a newly developed red filter ladder," Journal of the Japan Association of Orthoptists, Japan Association of Orthoptists, 2017, Vol. 46, pp. 245-256

[0004] However, in conventional configurations, the transmittance of the filter changes stepwise for each window, and the change in transmittance of the window is not continuous, resulting in abrupt changes in the brightness of the light seen by the subject. Therefore, with conventional configurations, it is difficult for the examiner to distinguish whether strabismus is caused by abrupt changes in brightness or whether the transmittance of the filter fitted to one eye is low enough to cause strabismus, resulting in an inaccurate measurement of fusional maintenance ability. Furthermore, ensuring the area of ​​multiple windows increases the size and weight of the main body. Therefore, the present invention was made in consideration of the above-mentioned circumstances, and its object is to provide a strabismus testing device that can accurately measure fusional maintenance ability while being compact and lightweight.

[0005] In order to achieve the above object, the present invention provides a strabismus examination instrument including a handheld main body, the main body including a window portion in which two light-transmitting members are arranged overlapping each other, and a variable mechanism that cooperates with the two light-transmitting members to continuously vary the transmittance of light passing through the window portion. This specification includes the entire contents of Japanese Patent Application No. 2023-204460, filed on December 4, 2023.

[0006] According to the present invention, fusional image maintenance ability can be accurately measured, and a compact and lightweight device can be achieved.

[0007] Figure 1 is a perspective view of a strabismus test instrument. Figure 2 is an exploded perspective view of a strabismus test instrument. Figure 3 is a plan view of a strabismus test instrument. Figure 4 is an enlarged view of Figure 3. Figure 5 is a perspective view of a strabismus test instrument. Figure 6 is a plan view of a strabismus test instrument. Figure 7 is an end view of a strabismus test instrument. Figure 8 is an end view of a strabismus test instrument. Figure 9 is a perspective view of a strabismus test instrument with the handheld body removed. Figure 10 is an enlarged view of Figure 9.

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [First embodiment] Figures 1, 2, and 3 are views showing a strabismus examination device 1 according to a first embodiment. Figure 1 is a perspective view of the strabismus examination device 1, Figure 2 is an exploded perspective view of the strabismus examination device 1, and Figure 3 is a plan view of the strabismus examination device 1.

[0009] The strabismus test instrument 1 is an instrument for measuring fusional maintenance ability. The strabismus test instrument 1 includes a handheld main body 2. The main body 2 includes a window 3 and a grip 4. The main body 2 is composed of a pair of cases 5 and 6. A red filter 7 and a pair of light-transmitting members 8 and 9 are stacked and disposed inside the window 3 of each of the cases 5 and 6, with one surface facing each other. The red filter 7 and the pair of light-transmitting members 8 and 9 are stacked and housed in the pair of cases 5 and 6, and are supported by the pair of cases 5 and 6. The window 3 is a portion through which the line of sight of a subject tested with the strabismus test instrument 1 passes, and has a circular shape. An operating unit 10 for rotating the light-transmitting member 9 within the plane of the window 3 is housed inside the grip 4 of each of the cases 5 and 6.

[0010] The red filter 7 is a circular plate that transmits long-wavelength visible light. The pair of light-transmitting members 8 and 9 are circular polarizing plates. Each of the pair of light-transmitting members 8 and 9 has a slit formed on one surface. The pair of light-transmitting members 8 and 9 change the transmittance of light passing through the window portion 3 by changing the relative angle between the slit of the light-transmitting member 8 and the slit of the light-transmitting member 9.

[0011] As shown in FIG. 2 , the strabismus examination instrument 1 includes a variable mechanism 11. The variable mechanism 11 continuously varies the transmittance of light passing through the window portion 3 by cooperating with a pair of light-transmitting members 8 and 9. A circular ring member 12 is attached to the outer periphery of the light-transmitting member 9. A circular rack gear 13 is formed on the surface of the circular ring member 12. The variable mechanism 11 includes a pinion gear 14 that meshes with the rack gear 13. An operating unit 10 that applies a rotational force to the pinion gear 14 is attached to a rotation shaft 15 of the pinion gear 14. The variable mechanism 11 is housed inside the pair of cases 5 and 6 with the axial direction of the rotation shaft 15 of the pinion gear 14 aligned with the axial direction of the shaft 4A of the grip portion 4. More specifically, the variable mechanism 11 is housed inside the pair of cases 5 and 6 with the rotation shaft 15 of the pinion gear 14 journaled by a bearing 17 of the case 6. It should be noted that the variable mechanism 11 continuously varying the light transmittance means that the light transmittance is gradually varied without jumping or discretely changing.

[0012] The operating unit 10 is rotated in a direction X perpendicular to the axis 4A of the grip 4. When the operating unit 10 is rotated to the right in Fig. 3, the pinion gear 14 rotates clockwise in Fig. 2, and the light transmitting member 9 rotates in the direction of arrow X1 in conjunction with the rotation of the pinion gear 14. When the operating unit 10 is rotated to the left in Fig. 3, the pinion gear 14 rotates counterclockwise in Fig. 2, and the light transmitting member 9 rotates in the opposite direction, i.e., in the direction of arrow X2 in conjunction with the rotation of the pinion gear 14. The light transmitting member 8 is fixed to the window 3 so as not to rotate in conjunction with the rotation of the light transmitting member 9.

[0013] 4 is an enlarged view of FIG. 3. As shown in FIG. 4, an arrow 18 is provided on the annular member 12, and a display unit 19 indicating the level of fusional image maintenance ability is provided on the window 3 on the case 6 side. The display unit 19 has a scale S indicating the level of fusional image maintenance ability. The scale S is provided in an annular shape on the window 3. The scale S is provided in small divisions. When the light transmitting member 9 rotates, the arrow 18 rotates integrally therewith, and the arrow 18 points to the scale S corresponding to the rotation angle of the light transmitting member 9. In this embodiment, when the arrow 18 points to the scale S, the pair of light transmitting members 8, 9 are in a state where the transmittance of light passing through the window 3 is highest. In other words, when the arrow 18 points to the scale S, the relative angle between the slits in the light transmitting member 8 and the slits in the light transmitting member 9 is approximately 0° when viewed from the window 3. Therefore, when the light-transmitting member 9 rotates in conjunction with the rotation of the annular member 12 and the arrow 18 moves from the scale S1 toward the scale S2 or the scale S3, the transmittance of the light passing through the window portion 3 decreases.

[0014] To measure fusional maintenance ability, an examiner such as a doctor grasps the grip 4 and places the window 3 over one of the eyes of a subject suffering from indirect exotropia. The examiner then measures the degree of fusional maintenance ability using the strabismus testing device 1. The examiner reduces the transmittance of light passing through the window 3 by rotating the operating unit 10 from a state in which the arrow 18 points to the scale S1, and stops rotating the operating unit 10 when strabismus occurs. At this point, the scale S indicated by the arrow 18 represents the degree of fusional maintenance ability. The examiner can easily measure the degree of the subject's fusional maintenance ability simply by checking the scale S indicated by the arrow 18.

[0015] As described above, the strabismus examination instrument 1 includes a handheld main body 2. The main body 2 includes a window 3 in which two light-transmitting members 8, 9 are arranged in an overlapping manner, and a variable mechanism 11 that causes the two light-transmitting members 8, 9 to cooperate to continuously vary the transmittance of light passing through the window 3.

[0016] This allows the transmittance of light passing through the window 3 to be continuously variable, thereby preventing sudden changes in the brightness of the light seen by the subject. This allows for accurate measurement of fusional maintenance ability. Furthermore, since two light-transmitting members 8 and 9 are arranged in the window 3, the number of windows 3 can be reduced compared to devices with multiple windows. Therefore, the strabismus testing device 1 can accurately measure fusional maintenance ability and can be made smaller and lighter.

[0017] The variable mechanism 11 rotates the light transmitting member 9 within the plane of the window portion 3 .

[0018] According to this, the light transmittance can be continuously varied by rotating the light transmitting member 9 within the plane of the window portion 3, so there is no need to provide a light transmitting member 9 with an area larger than the window portion 3, and there is no need to ensure that the range over which the light transmitting member 9 can be rotated is larger than the area of ​​the window portion 3. Therefore, it is possible to achieve a further reduction in size and weight.

[0019] The variable mechanism 11 includes a rack gear 13 that rotates the light transmitting member 9 , a pinion gear 14 that meshes with the rack gear 13 , and an operating unit 10 that applies a rotational force to the pinion gear 14 .

[0020] According to this, the light transmittance can be changed by operating the operation unit 10, so that the fusion maintenance ability can be measured more easily.

[0021] The main body 2 includes a grip portion 4 that supports the window portion 3. The operation portion 10 is disposed on the grip portion 4.

[0022] This allows the transmittance of light passing through the window portion 3 to be changed by the hand holding the strabismus test instrument 1, making it easier to measure the ability to maintain fusion.

[0023] The operating portion 10 is rotated in a direction perpendicular to the axis 4A of the grip portion 4.

[0024] This allows the subject to move the fingers of the hand gripping the grip portion 4 in the direction in which the subject wishes to move his or her line of sight, making it easier to measure the subject's ability to maintain fusion.

[0025] In the window portion 3, a red filter 7 is disposed so as to overlap two light transmitting members 8 and 9.

[0026] When strabismus occurs, diplopia occurs, and the subject sees the color of the visual object as split into red and non-red colors. This allows the subject to easily report the timing of the occurrence of strabismus to the examiner, allowing the examiner to accurately grasp the timing of the occurrence of strabismus. Therefore, by including the red filter 7, the strabismus examination instrument 20 can increase the possibility of more accurately measuring fusional maintenance ability.

[0027] In the first embodiment described above, the operation unit 10 is provided on the grip portion 4, but the operation unit 10 does not have to be provided on the grip portion 4. The operation unit 10 may be provided, for example, near the connection between the window portion 3 and the grip portion 4.

[0028] In the first embodiment described above, the light transmitting member 9 is configured to be rotated relatively manually. In other embodiments, the light transmitting member 9 may be rotated electrically. In this case, the strabismus examination instrument 1 includes a battery, a control device having a processor such as a CPU (Central Processing Unit), a motor that rotates the pinion gear 14, a button that specifies the rotation direction of the motor, wiring, etc., which may be attached to the main body 21. In the strabismus examination instrument 1 of this other embodiment, the control device rotates the motor in response to a button operated by the examiner, thereby electrically rotating the light transmitting member 9.

[0029] In the first embodiment described above, the light transmitting member 9 is configured to rotate, but the light transmitting member 8 may be rotated by the same method as the light transmitting member 9 .

[0030] In the first embodiment described above, the light transmitting member 9 is configured to rotate, but the light transmitting members 8 and 9 may be configured to rotate in different directions.

[0031] In the first embodiment described above, the red filter 7, the light-transmitting member 8, and the light-transmitting member 9 are arranged in the order of red filter 7, light-transmitting member 8, and light-transmitting member 9 from case 5 to case 6, but the arrangement order of the red filter 7, the light-transmitting member 8, and the light-transmitting member 9 is not limited to this and may be in any order.

[0032] In the first embodiment described above, the red filter 7 is arranged inside the window portion 3, but the red filter 7 may be arranged outside the window portion 3. In this case, the red filter 7 may be arranged detachably outside the window portion 3 using a magnet or the like.

[0033] In the first embodiment described above, the strabismus examination instrument 1 is configured to include the red filter 7, but the strabismus examination instrument 1 does not have to include the red filter 7. Furthermore, the strabismus examination instrument 1 may include a color filter other than transparent, such as a green filter or a blue filter, instead of the red filter 7. Furthermore, the strabismus examination instrument 1 may include an ND filter instead of the red filter 7.

[0034] The first embodiment described above merely shows one aspect of the present invention, and any modifications and applications are possible within the scope of the present invention.

[0035] Second Embodiment Next, a second embodiment will be described. Fig. 5 is a perspective view of the oblique vision examination instrument 20. Fig. 6 is a plan view of the same. Figs. 7 and 8 are end views of the same. Fig. 9 is a perspective view of the oblique vision examination instrument 20 with the handheld main body 21 removed. Fig. 10 is an enlarged view of Fig. 9.

[0036] The strabismus test instrument 20 is an instrument for measuring fusion maintenance ability, similar to the strabismus test instrument 1. The strabismus test instrument 20 has a hollow box-shaped main body 21. The main body 21 has a window frame 25 that holds a pair of light-transmitting members 23, 24, and this window frame 25 has a pair of window portions 22 on upper and lower opposing surfaces in FIG.

[0037] The pair of light-transmitting members 23, 24 are wedge-shaped members having the same slope and are colored red. Convex pieces 26 extending in the longitudinal direction are formed on both short-side ends of the pair of light-transmitting members 23, 24. The pair of light-transmitting members 23, 24 are inserted into the main body 21 so that the convex pieces 26 fit into concave grooves 27 extending in the longitudinal direction and formed in the inner wall of the main body 21. The wedge-shaped light-transmitting members 23, 24 are held in the window frame 25 with their opposing surfaces facing each other and their opposing surfaces parallel or approximately parallel.

[0038] The strabismus examination instrument 20 includes a variable mechanism 28. The variable mechanism 28 is a mechanism that linearly varies the transmittance of light passing through the window portion 22 by cooperating with a pair of light-transmitting members 23, 24. A rack gear 29 extending in the longitudinal direction is formed on each of the opposing surfaces of the pair of light-transmitting members 23, 24 at both ends in the shorter direction. The variable mechanism 28 includes two pinion gears 30, 31 that mesh with the rack gear 29 formed at one end, and two pinion gears 32, 33 that mesh with the rack gear 29 formed at the other end. The pinion gears 30, 32 are gears that share a rotation shaft 34, and both ends of the rotation shaft 34 are supported in the groove 27. The pinion gears 31, 33 are gears that share a rotation shaft 35, and both ends of the rotation shaft 35 are supported in the groove 27.

[0039] In the strabismus examination instrument 20, at least one of the two light-transmitting members 23, 24 is moved in the longitudinal direction. When the light-transmitting member 23 is moved in the direction of arrow X3 in the longitudinal direction, the pinion gears 30, 31, 32, and 33 rotate counterclockwise in FIG. 9, and the light-transmitting member 24 slides in the direction of arrow X4 in the longitudinal direction. In other words, when the light-transmitting member 23 is moved in the direction of arrow X3, the light-transmitting member 24 slides in the direction of arrow X4, with the tip of the light-transmitting member 24 moving away from the main body 21. On the other hand, when the light-transmitting member 23 is moved in the direction of arrow X4 in the longitudinal direction, the pinion gears 30, 31, 32, and 33 rotate clockwise in FIG. 9, and the light-transmitting member 24 slides in the direction of arrow X3. The same is true for light transmitting member 24: when light transmitting member 23 is moved in the direction of arrow X3, it slides in the direction of arrow X4, and when light transmitting member 23 is moved in the direction of arrow X4, it slides in the direction of arrow X3. When light transmitting member 23 slides in the direction of arrow X3, light transmitting members 23, 24 also slide within the plane of window portion 22, and the thickness of light transmitting members 23, 24 increases inside main body 2, and the transmittance of light passing through window portion 22 decreases. On the other hand, when light transmitting member 23 slides in the direction of arrow X4, light transmitting members 23, 24 also slide within the plane of window portion 22, and the thickness of light transmitting members 23, 24 decreases inside main body 2, and the transmittance of light passing through window portion 22 increases.

[0040] To measure fusional maintenance ability, an examiner such as a doctor holds the main body 21 and places the window 22 over one of the eyes of a subject suffering from indirect exotropia. The examiner then measures the degree of fusional maintenance ability using the strabismus testing device 20. The examiner moves at least one of the light-transmitting members 23, 24 to reduce the transmittance of light passing through the window 22, and stops the sliding of the light-transmitting members 23, 24 when strabismus occurs. This allows the examiner to measure the degree of the subject's fusional maintenance ability.

[0041] As described above, the variable mechanism 28 slides the light transmitting members 23 and 24 within the plane of the window portion 22 .

[0042] This allows the light transmittance to be linearly changed by sliding the light-transmitting members 23, 24 within the surface of the window portion 3, so that the light transmittance can be linearly changed with one window portion 3, thereby making it possible to reduce the size and weight.

[0043] The main body 21 includes a window frame 25. The light transmitting members 23 and 24 have wedge shapes with the same slope. The window frame 25 holds the light transmitting members 23 and 24 facing each other.

[0044] This makes it possible to make the light transmittance at the window 22 uniform, and to prevent the occurrence of a situation in which the timing of occurrence of strabismus varies depending on the position of the eye to which the window 22 is applied. Therefore, fusional maintenance ability can be measured more accurately.

[0045] The light transmitting members 23 and 24 have rack gears 29 on their opposing surfaces. The window frame 25 has pinion gears 30, 31, 32, and 33 that mesh with the rack gear 29.

[0046] According to this, the light transmittance can be changed by manipulating the light transmitting members 23 and 24, so that the fusional image maintenance ability can be measured more easily.

[0047] The light transmitting members 23 and 24 are colored red.

[0048] When strabismus occurs, diplopia occurs, and the subject sees the color of the visual object as split into red and non-red colors. This allows the subject to easily report the timing of the occurrence of strabismus to the examiner, and the examiner can accurately grasp the timing of the occurrence of strabismus. Therefore, by making the light-transmitting members 23 and 24 red, the strabismus examination instrument 20 can increase the possibility of more accurately measuring the ability to maintain fusion.

[0049] In the second embodiment described above, the light-transmitting members 23 and 24 are configured to be red, but the light-transmitting members 23 and 24 may be configured to be a color other than red as long as they are a color other than transparent.

[0050] In the second embodiment described above, the light-transmitting members 23, 24 are wedge-shaped members, but the shape of the light-transmitting members 23, 24 does not have to be wedge-shaped as long as the light-transmitting members 23, 24 are colored so that the color gradually becomes darker from one end to the other end in the longitudinal direction.

[0051] It should be noted that the above-described embodiments are intended to illustrate the technology of the present invention, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0052] REFERENCE SIGNS LIST 1, 20 Strabismus examination device 2, 21 Main body 3, 22 Window portion 4 Grip portion 7 Red filter 8, 9, 23, 24 Light-transmitting member 10 Operation portion 11, 28 Variable mechanism 13, 29 Rack gear 14, 30 to 33 Pinion gear 25 Window frame

Claims

1. A strabismus examination instrument comprising a hand-held main body, the main body comprising: a window portion in which two light-transmitting members are arranged so as to overlap; and a variable mechanism that causes the two light-transmitting members to cooperate with each other to continuously vary the transmittance of light passing through the window portion.

2. The strabismus examination instrument according to claim 1, wherein the variable mechanism rotates the light transmitting member within the plane of the window portion.

3. The strabismus examination instrument according to claim 2, wherein the variable mechanism comprises a rack gear that rotates the light-transmitting member, a pinion gear that meshes with the rack gear, and an operating unit that applies a rotational force to the pinion gear.

4. The strabismus examination instrument according to claim 3, wherein the main body includes a grip portion that supports the window portion, and the operating portion is disposed on the grip portion.

5. The strabismus examination instrument according to claim 4, wherein the operating portion is rotated in a direction perpendicular to the axis of the grip portion.

6. The strabismus examination tool according to any one of claims 1 to 5, wherein a color filter other than transparent is arranged in the window portion so as to overlap the two light transmitting members.

7. The strabismus examination instrument according to claim 1, wherein the variable mechanism slides the light transmitting member within a plane of the window portion.

8. The strabismus examination instrument according to claim 7, wherein the main body comprises a window frame having the window portion, the light-transmitting members have wedge shapes having the same gradient as each other, and the window frame holds the light-transmitting members facing the window portion.

9. The oblique vision examination instrument according to claim 8, wherein the light transmitting members have rack gears on opposing surfaces, and the window frame is provided with a pinion gear that meshes with the rack gear.

10. The strabismus examination tool according to any one of claims 7 to 9, wherein the light-transmitting member is of a color other than transparent.

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