JPH01181843A - Ophthalmic device - Google Patents

Abstract

PURPOSE:To safely and easily switch two measuring systems having different functions by providing the edge part position recognizing means and the edge part position setting means of a detected edge which is in contact with the cornea of an eye to be examined. CONSTITUTION:A first measuring system measuring the cornea refraction force of an examined eye E and a second measuring system obtaining an eye axis length are provided in a main body 2 provided on a sliding stand 1. In the second measuring system, when a contact shoe slides in the direction of the examined eye E, a motor driving controller drives and controls an electric motor 16 at a high speed in an initial sliding stage, and when the switch of a probe holder 13 is turned on, the low-speed sliding of the electric motor 16 is controlled. Thus, a switching time is shortened, and a fear that the probe 12 collides with the cornea of the examined eye E at intersive inertia force can be evaded. At the time of the measurement of cornea refraction force, after a suitable alignment operation is carried out while a television monitor 8 is being observed, when a mode is switched to an eye axis length measuring mode, the alignment operation is not readjusted, the measurement of the eye axis length can be immediately measured.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a measuring system for measuring corneal refractive power in a non-contact manner to the cornea of an eye to be examined, such as a measuring means, and an ultrasonic axial length measuring means. The present invention relates to an ophthalmological device that combines a measuring system that performs contact measurement, such as the above.

[Prior Art] For example, in cataract surgery in which a cloudy crystalline lens is extracted and an artificial crystalline lens is inserted, when selecting an artificial crystalline lens with an appropriate refractive power, the corneal refractive power is measured using an optical measuring device. Next, the length from the cornea to the retina is determined using an ultrasonic axial length measuring device, and the refractive power of the artificial crystalline lens is calculated from both values using a predetermined formula.

[Problems to be solved by the invention] However, in the past, corneal refractive power and axial length were measured using separate devices. The operation of performing seven alignments and then measuring must be performed separately for each device, which poses a problem that measurement is troublesome and time-consuming.

Furthermore, not only is a large installation space required,
There are also problems such as having to move patients with poor eyesight.

Therefore, there is a desire to combine the function of measuring corneal refractive power and the function of measuring axial length in one device, but the corneal refractive power measurement system requires measurement while maintaining a relatively long spatial distance. In contrast, the axial length measurement system requires the detection end to be in contact with the cornea of the eye to be examined. If you try to move the sliding table in the optical axis direction to perform these two measurements, the alignment with the subject's eye will collapse, resulting in the problem of having to re-align it. There is a point.

Furthermore, when switching the ultrasound probe to the measurement state using power, if the end position of the probe with respect to the cornea is set uniformly, it becomes impossible to adjust the contact pressure between the probe and the cornea.
There is also the problem that the operator's requests cannot be fully met.

[Object of the Invention] An object of the present invention is to solve the above-mentioned problems and to enable safe and easy switching between two measuring systems with different functions. By providing an end position recognition means and an end position setting means,
An object of the present invention is to provide an ophthalmologic apparatus in which the end position of a detection end can be freely set.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to provide a first measurement system that detects eye information to be examined while maintaining a predetermined distance from the cornea of the eye to be examined; A second measurement system that detects information on the eye to be examined with the end of the detection end in contact with the cornea is attached to the measuring instrument main body supported on the same sliding table,
In an ophthalmological apparatus in which the first and second measurement systems can be switched while the position of the eye to be examined is fixed, when the measurement state of the first measurement system is switched to the measurement state of the second measurement system. , the end of the detection end of the second measurement system is set to a variable predetermined position in the optical axis direction of the measuring instrument body with respect to the cornea position of the eye to be examined in the proper measurement state of the first measurement system; This ophthalmologic apparatus is characterized by having an end position setting means for detecting the position of the detection end, and an end position recognition means for recognizing the position of the detection end.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

In FIG. 1, inside the main body 2 provided on the sliding table 1,
A first measurement system for measuring the corneal refractive power of the eye E to be examined and a second measurement system for determining the axial length are provided. 1st
In the measurement system, an objective lens 3 is placed opposite the eye E to be examined.
A two-dimensional image sensor 7 consisting of a mirror 4.5, an imaging lens 6, a COD, etc. is arranged behind it along the optical path, and the output of this two-dimensional image sensor 7 is connected to a television monitor 8. There is. And objective lens 3, mirror 4.5
has an integral structure, and a wire 10 driven by an electric motor 9
It can be moved up and down. Further, around the objective lens 1, as shown in FIG. 2, a plurality of projection index light sources 11a to 11d made of light emitting diodes or the like are arranged at equal intervals around the optical axis. Furthermore, in the second measurement system, the ultrasonic probe 12 placed behind the mirror 4 is connected to the sliding guide member 14 via the probe holder 13.
The ultrasonic probe 12 is held forward by a tension spring 15. Further, the ultrasonic holder 13 can be moved back and forth by a wire 17 moved by an electric motor 16. In addition, in Figure 1,
Reference numerals 18 and 19 indicate guide rollers that guide the wires 10 and 17, respectively, 20a an operation stick, and 20b a vertical adjustment ring. Here, the projection target light sources 11a to lid are placed with a predetermined spatial distance between them. When projected onto the cornea of the optometrist E, corneal reflection images of the projection target light sources 11a to lid are formed due to the convex mirror action of the cornea. It is well known that since the mutual relationship between the positions of light spots in an image changes, corneal refractive power, degree of corneal astigmatism, and axial angle can be determined by detecting this change.

The first measurement system detects the corneal reflection images of the projection target light sources 11a to 11d by forming an image on a two-dimensional image sensor 7 using an optical system consisting of an objective lens 3, a mirror 4.5, and an imaging lens 6. ing. This detection signal is processed in an electric circuit (not shown) and further subjected to arithmetic processing to determine corneal refractive power, corneal astigmatism, and axial angle. The two-dimensional image sensor 7 can be used not only to detect measurement signals but also as a mechanism for observing the anterior segment of the eye E. While observing the anterior segment on the TV monitor 8, alignment can be performed by operating the sliding table 1. It is made possible.

In the second measurement system, switches 21a and 21b for detecting the position of the probe holder 13 are attached to a switch base plate 22, as shown in FIG. The feed shaft 2
By turning an adjustment knob 26 provided at the end of the probe 4, the positions of the switch base plate 22, that is, the switches 21a and 21b can be moved in the sliding direction of the probe 12 and set to any desired position. . Further, a pointer 27 is provided on the switch base plate 22, and the setting position can be read from a scale plate 28 combined with the pointer 27. An ultrasonic oscillator and a receiver are built into the probe 12, and the probe 12 is connected to an electric circuit section (not shown) via a cable 12a.

When the probe 12 slides in the direction of the eye E, a motor drive controller (not shown) switches the electric motor 1 at a high speed at the beginning of the slide.
6, and when the probe holder 13 turns on the switch 21a, the electric motor 16 is driven and controlled for low-speed sliding.
Further, when the probe holder 13 reaches a position where the switch 21b is turned on, the electric motor 16 is stopped. This shortens the switching time and allows the probe 12 to connect to the cornea E of the eye E.
It is possible to avoid the risk of hitting c with a strong inertial force.

With the ultrasound probe 12 in contact with the cornea Ec of the eye E, ultrasonic pulses are emitted from the tip of the probe 12 and the reflected echo from the retina of the eye E is received. It is well known that the axial length from the surface of Ec to the retina can be detected and a measured value obtained.

After measuring the corneal refractive power and axial length of the eye E in this way, these values can be calculated using empirically obtained formulas.
It is also well known that the refractive power of an artificial lens can be calculated.

In this embodiment, when measuring the corneal refractive power, the ultrasound probe 12
is retracted behind the mirror 4 so as not to obstruct the corneal refractive power measurement optical path. However, when switching to the axial length measurement mode using a changeover switch (not shown), the objective lens 3 and mirror 4
．． 5 descends, then the probe 12 starts moving in the direction of the eye E, and the probe holder 13 closes the switches 21a and 21b.
After sequentially turning on the probe 12, the probe 12 stops moving and its tip contacts the cornea Ha, resulting in the state shown in FIG. 3. At this time, the objective lens 3 and the mirror 4.5 are lowered by a drive mechanism including an electric motor 9, a wire 10, and the like. Similarly, the movement of the probe 12 is also performed by a drive mechanism consisting of an electric motor 16, a wire 17, and the like.

Here, the position of the cornea of the eye E to be examined when measuring the corneal refractive power should be approximately the same as the position of the tip of the ultrasound probe 12 when measuring the axial length, or the position of the tip of the ultrasound probe 12 should be slightly aligned in the optical axis direction. The adjustment knob 26 can be used to arbitrarily set whether or not it should be exposed. By doing so, if the mode is switched to the axial length measurement mode after performing appropriate alignment operations while observing the television monitor 8 during corneal refractive power measurement, the probe 12 can be adjusted without readjusting the alignment. The tip of the eyepiece is advanced to a position where it touches the cornea, and the axial length can be immediately measured.

FIG. 4 shows a second embodiment, in which the same reference numerals as in FIG. 3 represent the same or equivalent members. In this embodiment, the switch base plate 2 on which the switches 21a and 21b are attached is
2a and 22b are separated, and the switches 21a and 21b are connected to the respective feed shafts 24a and 24b and adjustment knobs 26a and 2.
6b allows for individual adjustment. Also,
The pointer 27b provided on the switch base plate 22b is the scale plate 2.
The scale 28a that is combined with the pointer 27a provided on the switch base plate 22a is the scale 28a that is combined with the pointer 27a provided on the switch base plate 22a.
b. With this configuration, probe 1
Since the position of the switch 21a that changes the sliding speed of the probe 2 to a low speed and the position of the switch 21b that detects the stop position of the probe 12 can be set independently, the mode can be changed from the refractive power measurement mode of the cornea Ec to the axial length measurement mode. It becomes possible to freely set the time required for switching.

FIG. 5 shows a third embodiment. In this embodiment, as a position detection means of the probe holder 13, a plurality of striped reflecting parts are provided as shown in FIG. Hole 30a
A non-contact photodetector consists of a mark plate 30 provided with a mark plate 30, a pair of light emitting elements 31 and a light receiving element 32 provided on the probe holder 13 side, and a light receiving element 33 for detecting a reference position placed at a reference position. The light receiving element 32 receives the reflected light from the light emitting element 31 toward the mark plate 30, and when the mark plate 30 moves and the light emitting element 31 comes near the reference position, the light from the light emitting element 31 is The light receiving element 33 receives the light through the light flux transmission hole 30a.

FIG. 7 shows an example of the signal processing system of this embodiment, in which pulsed signals output from the light receiving element 32 as the probe holder 13 slides are integrated by an adder 34.
The addition output of the integrator 34 is reset by the output signal of the light receiving element 33. The speed calculator 35 includes an initial speed setting device 36,
The data from the final speed setter 37 and the adder 34 are input, a speed control signal S is calculated and outputted, and the electric motor 16 shown in FIG. 1 is driven and controlled via the motor drive controller 38. The content of the calculation in the speed calculator 35 is that the speed change from the initial speed value to the final speed value by the initial speed setter 36 and the final speed setter 37 is calculated by the adder 3.
It is possible to calculate as a function for the output data of No. 4 and set an arbitrary function type in the speed calculator 35. On the other hand, the speed calculator 35 outputs a stop command signal to the speed control signal S when the output data of the adder 34 and the value of the end position setter 39 match, and when the output signal of the light receiving element 33 is input. It is designed to give. Also in this example,
It is possible to control the speed to minimize the time required to switch from the corneal refractive power measurement mode to the axial length measurement mode.

In this embodiment, the mark plate 30 is constructed of a 1-bit encoder, but it can also be constructed of a multi-bit encoder that can read the absolute value of the position.

Further, in the above-described embodiment, the corneal refractive power measuring means is held at a predetermined distance from the cornea of the eye to be examined as the first measurement system for detecting information about the eye to be examined, and the end of the detection terminal is brought into contact with the cornea. In this case, an ultrasonic axial length measuring means is applied as a second measurement system for detecting information on the subject's eye, and the detection end is an ultrasonic probe, but this is merely an example. Of course, other measurement means may be applied to the first measurement system and the second measurement system.

[Effects of the Invention] As explained above, the ophthalmological device according to the present invention allows the end position of the detection end that contacts the cornea of the eye to be examined to be set arbitrarily, so that For example, corneal refractive power can quickly shift from the functional state of the first measuring system, which performs measurements while maintaining a distance, to the functional state of the second measuring system, which performs measurements by bringing the detection end into contact with the cornea. If the time required for switching from the measurement mode to the axial length measurement mode is set appropriately by setting the low-speed sliding start position of the probe appropriately, the corneal refractive power and the axial length can be can be measured continuously and quickly, making it possible to significantly reduce the burden on patients and practitioners during cataract surgery and the like.

[Brief explanation of the drawing]

The drawings show an embodiment of the ophthalmological apparatus according to the present invention, in which FIG. 1 is an overall configuration diagram, FIG. 2 is a front view of an example of the arrangement of projection index light sources, and FIGS. FIG. 6 is a plan view of the mark plate, and FIG. 7 is a block diagram of the signal processing system. 1 is a sliding table, 2 is a main body, 3 is an objective lens, 7 is a two-dimensional image sensor, 8 is a television monitor, 9.16 is an electric motor, 1
0.17 is a wire, 11a to 11d are projection target light sources, 1
2 is an ultrasonic probe, 13 is a probe holder, 14 is a sliding guide member, 15 is a tension spring, 21a, 21b are switches, 22 is a switch base plate, 24 is a feed shaft, 25 is a male screw, 26 is an adjustment knob, 27 is a pointer, 28 is a scale plate, 3
0 is a mark plate, 30a is a luminous flux transmission hole, 31 is a light emitting element,
32 and 33 are light receiving elements, 34 is an adder, 35 is a speed calculator, 36 is an initial speed setter, 37 is a final speed setter, 38 is a motor drive controller, and 39 is an end position setter. Figure 1 Figure 2 Figure 0-11c Figure 5 Ryo 6 Figure 7

Claims (1)

[Scope of Claims] 1. A first measurement system that detects information on the eye to be examined while maintaining a predetermined distance from the cornea of the eye to be examined, and an end of the detection end in contact with the cornea of the eye to be examined. A second measuring system for detecting information on the eye to be examined is attached to the main body of the measuring instrument supported on the same sliding table, and the first,
In an ophthalmological apparatus in which a second measurement system can be switched, when the measurement state of the first measurement system is switched to the measurement state of the second measurement system, the end of the detection end of the second measurement system an end position setting means for setting the detection end to a variable predetermined position in the optical axis direction of the measuring instrument body with respect to the corneal position of the eye to be examined in the proper measurement state of the first measurement system; An ophthalmological apparatus characterized by having an end position recognition means for recognizing. 2. A driving means for setting the functional state of the second measurement system using power, and a speed control means for controlling the driving speed of the detection end based on the output of the end position recognition means. The ophthalmological device according to scope 1. 3. The ophthalmologic apparatus according to claim 1, wherein the first measurement system is corneal refractive power measurement means, and the second measurement system is ultrasonic axial length measurement means.