JP4689061B2 - Ophthalmic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ophthalmologic apparatus such as a non-contact tonometer that automatically aligns an eye to be examined and a measurement head and automatically performs measurement when the misalignment falls within a predetermined range.
[0002]
[Prior art]
Conventionally, there is known a non-contact tonometer that automatically aligns an eye to be examined and a measurement head and automatically performs measurement when the misalignment falls within a predetermined range.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional example, when the fixation of the eye to be examined is poor, it takes time to align the alignment, and measurement may not be started easily, which causes a problem that the burden on the subject increases. In addition, when the alignment deviation is outside the specified range, if the measurement is forcibly performed by pressing the measurement start switch, the measurement will be performed regardless of the size of the alignment deviation. There is a problem in that it causes a wasteful measurement.
[0004]
An object of the present invention is to provide an ophthalmic device that solves the above-described problems and can quickly measure even an eye to be examined with poor fixation.
[0005]
Another object of the present invention is to provide an ophthalmic device that can prevent useless measurement with low reliability.
[0006]
[Means for Solving the Problems]
Further, an ophthalmic apparatus according to the present invention includes an alignment detection unit that detects an amount of misalignment between an eye to be measured and a measurement head, a drive unit that moves the position of the measurement head based on the amount of misalignment, and an object to be automatically detected. A control means for performing measurement when the alignment deviation detected by the alignment detection means is within the first allowable range, an input means for starting measurement, and automatic alignment are performed. And a prohibiting means for prohibiting the measurement when the amount of misalignment exceeds a second allowable range wider than the first allowable range when the measurement is forcibly performed by the input of the input means. It is characterized by.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 is a cross-sectional view of an auto-alignment tonometer according to an embodiment. A guide shaft 2 and a feed screw 3 are horizontally mounted on a left and right moving frame 1, and a left and right drive motor 4 is mounted on a side surface of the left and right moving frame 1. Is fixed. A vertical motion frame 5 is placed on the left-right motion frame 1, and a bearing 6 and a female screw bearing 7 fixed to the lower portion of the vertical motion frame 5 are respectively a guide shaft 2 and a feed screw 3 of the left-right motion frame 1. The vertical movement frame 5 can be moved in the horizontal direction.
[0009]
A guide shaft 8 and a feed screw 9 are erected in the vertical direction on the vertical motion frame 5, and a vertical drive motor 10 is fixed to the lower part of the vertical motion frame 5, and the vertical drive motor 10 is one of the feed screws 9. It is directly connected to the end. Further, the guide shaft 8 and the feed screw 9 are respectively fitted to a bearing (not shown) fixed to the longitudinal motion frame 11 and a female screw bearing 12 so that the longitudinal motion frame 11 can be moved up and down. A guide shaft 13 and a feed screw 14 are installed on the longitudinal motion frame 11. A longitudinal drive motor 15 is directly connected to one end of the feed screw 14, and the longitudinal drive motor 15 is fixed to the longitudinal motion frame 11. .
[0010]
The guide shaft 13 and the feed screw 14 of the back and forth motion frame 11 are respectively fitted to a bearing (not shown) and a female screw bearing fixed to the intraocular pressure measuring unit 16, and the feed screw 14 is rotated by the rotation of the front and rear drive motor 15. The intraocular pressure measurement unit 16 is movable in the front-rear direction along the guide shaft 13. In this way, a mechanism for freely moving the tonometry part 16 relative to the eye E in three dimensions in the front-rear, up-down, left-right directions is configured.
[0011]
Further, a joint portion 17 of an air inflow portion (not shown) is attached to the side surface of the intraocular pressure measurement portion 16, and an air generation portion for blowing air is connected to the joint portion 17 via a flexible tube. The air generating unit is composed of a rotary solenoid, a piston, a piston moving arm, and a cylinder. The piston is horizontally moved by the rotation of the rotary solenoid, and the air in the cylinder is passed through the flexible tube and the joint 17 to the intraocular pressure measuring unit 16. It comes to send to.
[0012]
Inside the intraocular pressure measurement unit 16, a nozzle 20 is disposed on an optical path O1 facing the eye E, two lenses 21 and 22 are provided on the front and rear sides of the nozzle 20, and a dichroic mirror 23 is provided behind the lenses 21 and 22. A mask 24, prisms 25a and 25b, a lens 26, and an image sensor 27 are sequentially arranged as shown in FIG. A lens 28, a half mirror 29, a dichroic mirror 30, a projection lens 31, and a measurement light source 32 are arranged on the optical path O 2 in the incident direction of the dichroic mirror 23, and the aperture 33 and corneal deformation are arranged in the reflection direction of the half mirror 29. A light receiving element 34 that is a light receiving portion of the detection system is disposed, and a fixation LED light source 35 is disposed in the incident direction of the dichroic mirror 30.
[0013]
FIG. 3 shows a configuration diagram of the electric control unit, and an MPU 40 for controlling the system is provided. The output of the image sensor 27 is connected to the MPU 40 and the image memory 42 via the A / D converter 41, and the image memory 42 is connected to the MPU 40. The outputs of the pressure sensor 43 that detects the pressure in the air chamber of the light receiving element 34 and the intraocular pressure measurement unit 16 are connected to the MPU 40 via the A / D converter 44. The output of the MPU 40 is connected to the left and right drive motor 4, the vertical drive motor 10 and the front and rear drive motor 15 via the motor drive circuit 45 to control the rotation direction and drive speed of the motors 4, 10 and 15. And is connected to the measurement light source 32 and the fixation LED light source 35 via the drive circuit 46, and has a function of controlling the on / off of each light source 32, 35 and the light quantity, and further connected to the rotary solenoid 47. And has a function of performing the drive control.
[0014]
First, the subject sits in front of the intraocular pressure measurement unit 16 and fixes the fixation LED light source 35 through the fixation target projection optical system. The light flux from the fixation LED light source 35 is reflected by the dichroic mirror 30, passes through the half mirror 29, passes through the nozzle 20 through the lens 28, and is guided to the eye E to be examined.
[0015]
In the observation optical system, the observation image of the eye E passes through the lens 21 and the lens 22 outside the nozzle 20, passes through the dichroic mirror 23, passes through the central opening of the mask 24, passes through the lens 26, and then passes through the lens 26. 27 and displayed on a display (not shown). The examiner operates the trackball or the like while viewing the image on the display, and images the eye E to be imaged on the imaging element 27 of the observation optical system of the tonometry part 16 so that the front / rear, up / down, left / right drive motor 4, 10 and 15 are driven to perform rough alignment.
[0016]
In the alignment projection optical system, the light beam from the measurement light source 32 passes through the projection lens 31, the dichroic mirror 30, and the half mirror 29, and is irradiated into the nozzle 20 through the lens 28 and the dichroic mirror 23. Head for.
[0017]
In the alignment light receiving optical system, a part of the optical system is shared with the observation optical system, and the light beam reflected by the cornea of the eye E is partially transmitted through the lens 21 and the lens 22 and through the dichroic mirror 23. Then, the light enters the prisms 25a and 25b that transmit only the wavelength light of the measurement light source 32 through the mask 24 and is separated into two light beams. One light beam is refracted downward by the left prism 25a, and the other light beam is The light is refracted upward by the right prism 25b.
[0018]
As a result, at an appropriate working distance, the spot image of the measurement light source 32 is imaged as two bright spots on the vertical line in the vicinity of the center on the image sensor 27. When the working distance is shifted back and forth, each of these two bright spots moves relative to each other in the left and right directions with reference to the bright spot position at the proper working distance. When the intraocular pressure measurement unit 16 moves in the vertical and horizontal directions with respect to the eye E, both the two bright spots move in the vertical and horizontal directions without changing their relative positions according to the amount of deviation.
[0019]
The output of the image sensor 27 that is a light receiving unit of the observation optical system and the alignment optical system is sent to a display (not shown) via an image synthesis circuit. In order to display the intraocular pressure measurement result and the alignment index, the image composition circuit receives a character composition signal from the MPU 40 and synthesizes it with the observation image and displays it on the display. Further, the observation image to be subjected to the alignment detection process is sent to the image memory 42 via the A / D converter 41 that digitizes the image. The image stored in the image memory 42 is taken into the MPU 40 and alignment position detection processing is performed.
[0020]
When a key input for starting auto-alignment is performed in a state where an alignment bright spot is reflected on the cornea of the eye E, the position of the alignment bright spot is detected, and a control signal of the MPU 40 is sent to a motor drive circuit according to the amount of deviation. 45, the front / rear, up / down and left / right drive motors 4, 10, 15 are driven. In this manner, feedback control of auto-alignment using the alignment optical system is performed, and the intraocular pressure measurement unit 16 is moved and set to an appropriate position so as to accurately match the appropriate alignment position with respect to the eye E. The motors 4, 10, and 15 can be driven by a trackball, mouse, or key input operation when the eye E cannot be detected by the observation optical system or the alignment optical system.
[0021]
In this way, when the misalignment amount is in an appropriate alignment state within a predetermined range, a trigger signal is generated from the MPU 40 to the drive circuit 46, and the rotary solenoid 47 is automatically driven. Thus, air is sent from the air generation unit to the air chamber, and air is blown from the nozzle 20 to the cornea.
[0022]
The projection optical system of the corneal deformation detection system is shared with the alignment projection optical system, and the light beam emitted from the measurement light source 32 passes through the projection lens 31, the dichroic mirror 30, and the half mirror 29, and enters the nozzle 20 via the lens 28. To the eye E to be examined. The cornea is deformed by the blown air, and the corneal reflected light beam passes through the lens 21 and the lens 22, is partially reflected by the dichroic mirror 23, further partially reflected by the half mirror 29, and received through the aperture 33. Guided to element 34. The output of the light receiving element 34 in this predetermined deformation state is pulsed, the pressure in the air chamber at the peak is measured by the pressure sensor 43, and the signal photoelectrically converted by the pressure sensor 43 and the light receiving element 34 is A / It is digitized by the D converter 44, sent to the MPU 40, and converted into intraocular pressure.
[0023]
At this time, when the fixation of the eye E is poor and does not match the proper alignment position, the fixation range is widened as shown in FIG. 4 according to the time from the start of auto-alignment. It is possible to perform automatic measurement by auto-alignment even for an eye E having a poor quality.
[0024]
In addition, for the eye E, whose fixation is very poor and the automatic alignment cannot be measured automatically even if the range of the proper alignment position is wide, usually the measurement start switch is pressed and auto alignment is interrupted. Measurement is forcibly performed. If the alignment deviation at this time is too large, a measurement error occurs even if measurement is performed, and unnecessary measurement is performed. Therefore, it is determined whether or not the alignment position when the measurement start switch is pressed is within a predetermined range for performing the forced measurement, and if it is not within the predetermined range, the measurement is not performed. .
[0025]
Depending on the time from the start of auto-alignment, the range of the proper alignment position should be kept constant without widening, and the measurement start switch is pressed for eye E with poor fixation, and auto-alignment is interrupted and forced. When measuring automatically, it is determined whether or not the alignment position when the measurement start switch is pressed is within a predetermined range for forced measurement. It is good also as a structure which does not perform.
[0026]
The present invention can be used not only for tonometers but also for other ophthalmic devices such as a fundus camera and an eye refractometer.
[0027]
【The invention's effect】
As described above, the ophthalmologic apparatus according to the present invention changes the allowable range of misalignment according to the time from the start of the movement of the measuring head, thereby enabling quick measurement even for the subject's eye with poor fixation. This can be done and the burden on the subject can be reduced.
[0028]
In addition, the ophthalmic apparatus according to the present invention has an alignment error when the measurement start is forced by pressing the measurement start switch because the fixation of the eye to be examined is poor during auto-alignment and the alignment error does not fall within a predetermined range. By prohibiting measurement when is greater than a predetermined value, useless measurement such as measurement errors can be prevented, and the burden on the subject can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an intraocular pressure measurement unit according to an embodiment.
FIG. 2 is a front view of a mask and a prism.
FIG. 3 is a configuration diagram of a block circuit of an electric control unit.
FIG. 4 is a graph showing an allowable range of misalignment.
[Explanation of symbols]
1, 5, 11 Movable frame 4, 10, 15 Motor 16 Intraocular pressure measurement unit 20 Nozzle 24 Mask 25a, 25b Prism 27 Imaging element 32 Measuring light source 34 Light receiving element 35 Fixation lamp 40 MPU
42 Image memory 43 Pressure sensor 47 Solenoid

Claims (1)

  Alignment detection means for detecting the amount of misalignment between the eye to be examined and the measurement head, drive means for moving the position of the measurement head based on the amount of misalignment, and alignment detection by automatically aligning the eye to be examined Control means for performing measurement when the amount of misalignment detected by the means is within the first allowable range, input means for starting measurement, and forced input by the input means during automatic alignment An ophthalmologic apparatus comprising: prohibiting means for prohibiting measurement when the amount of misalignment exceeds a second allowable range that is wider than the first allowable range.

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