阅读说明：本技术 眼屈光力测量设备以及方法 (Ophthalmic refractive power measurement apparatus and method ) 是由 边光春 山藤大辅 于 2019-05-30 设计创作，主要内容包括：本公开的一个方面的测量设备朝受检眼的眼底投射测量光并接受来自眼底的反射光,并且基于光接收信号对受检眼的眼屈光力进行测量。而且对测量值的可靠度进行判定。具体而言,以不定次数连续执行基于光接收信号对眼屈光力进行测量的处理,直到符合结束条件为止。每次执行处理时将所获得的眼屈光力的测量值与表示测量值的可靠度的信息共同显示在显示器上。(A measurement apparatus of one aspect of the present disclosure projects measurement light toward a fundus of an eye to be examined and receives reflected light from the fundus, and measures eye refractive power of the eye to be examined based on a light reception signal. And the reliability of the measured value is determined. Specifically, the process of measuring the eye refractive power based on the light reception signal is continuously executed an indefinite number of times until the end condition is satisfied. The obtained measurement value of the ocular refractive power is displayed on a display together with information indicating the reliability of the measurement value each time the processing is performed.)

1. An ophthalmic refractive power measurement apparatus, characterized by having:

A light projecting unit configured to project measurement light toward a fundus of an eye to be examined;

a light receiving section configured to receive reflected light from the fundus; and

A control part, and

The control unit is configured to control the operation of the motor,

continuously performing a process of measuring an eye refractive power of the eye to be inspected based on the light reception signal from the light receiving section an indefinite number of times until an end condition is met, and

The reliability of the measured value of the ocular refractive power is judged each time the processing is performed,

The measured value is displayed on a display together with information representing the degree of reliability each time the process is performed.

2. The ophthalmic optical power measurement device of claim 1,

the control unit starts the continuous execution of the processing without performing the automatic fogging.

3. The ophthalmic optical power measurement device of claim 1 or 2,

Has an input unit configured to input an instruction from an operator, and

the control unit continuously executes the processing during a period from when a start instruction is input through the input unit to when an end instruction is input through the input unit.

4. The ophthalmic optical power measurement apparatus of any one of claims 1-3,

the control unit displays the measurement value on the display in a display format corresponding to the reliability among a plurality of predetermined display formats, and thereby displays the measurement value and information indicating the reliability on the display together.

5. The ophthalmic optical power measurement device of claim 4,

The control unit displays the measured value on the display in a color corresponding to the reliability among a plurality of predetermined colors.

6. The ophthalmic optical power measurement apparatus of any one of claims 1-5,

The control unit displays a list of a plurality of measurement values of the eye refractive power obtained by executing the processing a plurality of times in a list display area of the display.

7. The ophthalmic optical power measurement device of claim 6,

The control section adds the measurement value of the ocular refractive power obtained by the processing to the list display area each time the processing is executed.

8. The ophthalmic optical power measurement device of claim 7,

When the space of the list display area is not enough to display a new measurement value of the eye refractive power, the control section deletes the measurement value of the lowest reliability among the measurement values of the eye refractive power already displayed in the list display area from the list display area.

9. The ophthalmic optical power measurement apparatus of any one of claims 1-8,

the control unit displays a latest measurement value among the plurality of measurement values of the eye refractive power obtained by executing the processing a plurality of times in a temporary display area of the display, and displays a list of measurement values with the reliability equal to or higher than a reference in a list display area of the display.

10. The ophthalmic optical power measurement apparatus of any one of claims 6-9,

The control unit arranges the plurality of measurement values in an order corresponding to the reliability of each of the plurality of measurement values displayed in the list display area.

11. The ophthalmic optical power measurement apparatus of any one of claims 1-10,

Has a detection unit configured to detect the position of the eye to be inspected, and

The control section determines the reliability based on the position of the eye to be inspected detected by the detection section.

12. The ophthalmic optical power measurement device of claim 11,

The control section further determines the reliability based on a spatial distribution of the reflected light indicated by the light reception signal.

13. the ophthalmic optical power measurement apparatus of any one of claims 1-12,

The control unit is configured to measure the eye refractive power in any one of a plurality of operation modes,

The plurality of operating modes includes a first operating mode and a second operating mode,

In the first operation mode, the control section measures the eye refractive power based on a light reception signal from the light receiving section after performing automatic fogging; in the second operation mode, the control section starts to continuously execute the processing without executing the automatic fogging.

14. The ophthalmic optical power measurement device of claim 13,

The control unit starts the operation in the second operation mode instead of the first operation mode when a specific condition is satisfied after the operation in the first operation mode is started, and starts the continuous execution of the processing without executing the automatic fogging.

15. the ophthalmic optical power measurement device of claim 14,

the control unit starts the operation in the second operation mode on the condition that at least one of a case where the measurement of the ocular refractive power in the first operation mode fails and a case where the reliability of the measured value of the ocular refractive power in the first operation mode is lower than a predetermined criterion is set.

16. A method of ocular refractive power measurement performed by a computer, comprising:

Continuously performing, at an indefinite number of times, a process of acquiring a light reception signal from an optical system configured to project measurement light toward a fundus of an eye to be examined and to receive reflected light from the fundus, and measuring an eye refractive power of the eye to be examined based on the light reception signal, until an end condition is satisfied;

determining the reliability of the measured value of the ocular refractive power each time the processing is performed; and

The measured value is displayed on a display together with information representing the degree of reliability each time the process is performed.

Technical Field

The present disclosure relates to an ocular refractive power measurement apparatus and method.

Background

Measuring devices for measuring the refractive power of an eye are known. In order to obtain a correct measurement value, it is preferable to perform measurement in a state where the position of the eye to be examined with respect to the measurement system is properly aligned and in a state where the eye to be examined is relaxed. Therefore, the conventional measuring device has a function of detecting the alignment state of the eye to be inspected and a function of putting the optotype in a foggy state. The measurement apparatus measures the eye refractive power with, for example, the alignment state as appropriate as a condition. The measurement apparatus performs a pre-measurement before performing a main measurement of eye refractive power, and brings the optotype into a foggy state based on the measurement result of the pre-measurement, thereby relaxing the eye to be examined.

there is also known a measuring apparatus that performs a plurality of consecutive measurements of the refractive power of the eye as disclosed in japanese patent laid-open No. 10-94516. The measuring device calculates the reliability of the measured value and selectively displays the measured value with higher reliability on the display section based on the calculated reliability information. Alternatively, the measuring device weights the measured values for each time based on the information of the reliability, and displays the weighted average of the measured values on the display section.

Disclosure of Invention

The measurement of the ocular refractive power is not only for adults but also for children. Accurate measurement of the eyes of a child is difficult due to the child's restlessness. For example, in order to set the optotype in a foggy state, it is necessary to predict the refractive power of the eye. However, if it is waited for the alignment state to become accurate in order to reliably form the fogging state, it takes time until the prediction amount is performed.

When the subject is a child, the alignment state may vary greatly. Due to this variation, the alignment state at the time of the pre-measurement is often inaccurate even if the pre-measurement is performed after the alignment state is accurate.

Even if a prescribed number of consecutive measurements are made, all or most of the measurements may be less reliable, so that it may be necessary to make the consecutive measurements again. The longer the time it takes to measure, the more likely the child will be to become uncooperative with the measurement. This tendency also increases the difficulty of making proper measurements for the child.

Accordingly, it is desirable for an aspect of the present disclosure to provide an ocular refractive power measurement apparatus and method that are sufficiently suitable for ambulatory subjects including children.

An ocular refractive power measurement apparatus according to an aspect of the present disclosure has a light projecting section, a light receiving section, and a control section. The light projecting unit is configured to project measurement light toward the fundus oculi of the eye. The light receiving portion is configured to receive reflected light from the fundus.

The control unit is configured to continuously perform a process of measuring the eye refractive power of the eye to be examined based on the light reception signal from the light receiving unit, an indefinite number of times until the end condition is satisfied. The control unit is further configured to determine the reliability of the measured value of the eye refractive power each time the processing is executed. The control unit is further configured to display the measured value and information indicating the reliability on the display at each execution of the processing.

The inventors of the present disclosure found that the measurement of the scatterity performed after the alignment state becomes accurate does not play an effective role from the viewpoint of improving the accuracy for a highly mobile subject. The number of measurements per unit time can be increased more than the measurement of the null-dispersion by continuously performing the measurement of the ocular refractive power. As a result, the possibility of obtaining more highly reliable measurement values in a short time is increased.

According to the present disclosure, it is also possible to help the inspector reliably grasp the situation regarding whether accurate measurement is being performed or not based on the display information of the display. By grasping the situation, the examiner can appropriately cope with the situation, and can complete an appropriate examination in a short time. Therefore, according to an aspect of the present disclosure, an ocular refractive power measurement apparatus sufficiently suitable for a restless subject can be provided.

According to another aspect of the present disclosure, the control unit may be configured to start the continuous execution of the above-described processing without performing the automatic fogging. The automatic fogging may mean that the optotype appearing in the eye to be examined is in a fogging state. Automatic fogging may also refer to the visual target being in a fogged state based on a pre-measured value of the ocular refractive power of the eye being examined. The automatic fogging may mean that the optotype is brought into a fogging state by changing the distance between the eye to be examined and the optotype.

For a person who is restless, the effect of automatic fogging is not good. In order to properly perform automatic fogging, it is generally necessary to pre-measure the refractive power of the eye after the alignment state becomes accurate. In this case, time is consumed before the main measurement starts. If the above-described processing is started to be continuously executed without performing the automatic fogging, the continuous measurement of the eye refractive power can be promptly performed.

according to another aspect of the present disclosure, the measuring apparatus may have an input portion configured to input an instruction from an operator. The control unit may be configured to start the continuous execution of the processing on condition that a start instruction is input through the input unit. The end condition may be input by an input unit. The control unit may be configured to continuously execute the above-described processing from when the start command is input to when the end command is input through the input unit.

Ending the continuous measurement based on the end instruction enables control of causing the measurement apparatus to continuously perform the continuous measurement until a desired measurement result is obtained, and to promptly end the measurement in a case where the desired measurement result is obtained.

According to another aspect of the present disclosure, the control unit may be configured to display the measurement value on the display in a display format corresponding to the reliability among a plurality of display formats defined in advance. The control unit may be configured to display the measured value on the display in a color corresponding to the reliability among a plurality of predetermined colors. The reliability is expressed based on the color, so that the examiner can easily grasp the examination condition.

According to another aspect of the present disclosure, the control unit may be configured to list the measured values of the ocular refractive power obtained by performing the processing a plurality of times in a list display area of the display. By displaying the list, the examiner can grasp the state of the eye examination by the continuous measurement.

According to another aspect of the present disclosure, the control section may be configured to add the measured value of the eye refractive power obtained by the processing to the list display area each time the processing is executed.

The control unit may be configured to delete, from the list display area, a measurement value with the lowest reliability among the measurement values of eye refractive power already displayed in the list display area when the space of the list display area is not enough for displaying a new measurement value of eye refractive power.

According to another aspect of the present disclosure, the control section may be configured to display a latest measurement value among a plurality of measurement values of the ocular refractive power obtained by performing the processing a plurality of times in a temporary display area of the display. The control unit may be configured to list and display measurement values having a reliability equal to or higher than a reference among the plurality of measurement values of the obtained eye refractive power in a list display area of the display.

According to another aspect of the present disclosure, the control unit may be configured to arrange the plurality of measurement values displayed in the list display area in an order corresponding to the reliability of each of the plurality of measurement values. With this configuration, information required by the examiner can be provided clearly and easily.

According to another aspect of the present disclosure, an eye refractive power measurement apparatus may have a detection portion configured to detect a position of an eye to be examined. The reliability of the measured values varies depending on the amount of positional deviation of the eye to be examined relative to the measuring system. Therefore, the control unit may be configured to determine the reliability of the measurement value based on the position of the eye to be examined detected by the detection unit.

the control unit may be configured to determine the reliability based on a spatial distribution of the reflected light indicated by the light reception signal. The reliability of the measured value can be determined, for example, from the image quality of the received light, based on the spatial distribution of the reflected light. Therefore, according to the above configuration, the reliability can be determined more accurately.

According to another aspect of the present disclosure, the control portion may be configured to measure the eye refractive power in any one of a plurality of operation modes. The plurality of operating modes may include a first operating mode and a second operating mode. In the first operation mode, the control portion may measure the eye refractive power based on the light reception signal from the light receiving portion after performing the automatic fogging. In the second operation mode, the control portion may start to continuously perform the above-described processing without performing the automatic fogging.

According to another aspect of the present disclosure, the control unit may be configured to start the operation in the second operation mode instead of the first operation mode when a specific condition is satisfied after the operation in the first operation mode is started, thereby starting the continuous execution of the above-described processing without executing the automatic fogging. The control unit may be configured to start the operation in the second operation mode on the condition that the measurement of the ocular refractive power in the first operation mode fails. The control unit may be configured to start the operation in the second operation mode on the condition that the reliability of the measured value of the eye refractive power in the first operation mode is lower than a predetermined criterion.

According to another aspect of the present disclosure, there may be provided an ocular refractive power measurement method performed by a computer. The ocular refractive power measurement method may include: continuously performing, at an indefinite number of times, a process of acquiring a light reception signal from an optical system configured to project measurement light toward a fundus of an eye to be examined and to receive reflected light from the fundus, and measuring an eye refractive power of the eye to be examined based on the light reception signal, until an end condition is satisfied; judging the reliability of the measured value of the ocular refractive power each time the processing is performed; and displaying the measured value together with information indicating the degree of reliability on a display each time the process is performed.

According to another aspect of the present disclosure, a computer program for causing a computer to execute an eye refractive power measurement method, and/or a recording medium having the computer program recorded thereon may be provided.

Drawings

fig. 1 is a schematic configuration diagram showing an optical system of a measuring apparatus.

fig. 2 is a block diagram showing a control system of the measuring apparatus.

Fig. 3 is a flowchart showing a main control process executed by the control apparatus.

Fig. 4 is a flowchart showing a first measurement process performed by the control device.

Fig. 5 is a flowchart showing a second measurement process performed by the control device.

Fig. 6 is a flowchart showing the iterative measurement process executed by the control device.

fig. 7 is a diagram showing an example of the configuration of a screen displayed on the display.

fig. 8 is a flowchart showing a list update process performed by the control device.

fig. 9 is an explanatory diagram about display of the measurement values corresponding to the reliability.

Fig. 10 is a flowchart showing a mode switching process executed by the control device.

Description of reference numerals

1 … measuring device; 3 … optical system of the device; 7 … control system;

11. 12 … illumination source; 20 … imaging element for observation; 22 … optotype light source; 24 … optotypes;

34 … aligning the light source; 36. 38 … alignment detection sensor; 40 … measuring light source;

54 … imaging element for measurement; 61 … drive 1; 62 … drive 2;

63 … drive 3 rd; 64 … drive No. 4; 70 … control device; 71 … processor;

73 a memory 73 …; a 75 … display; 79 … input interface; 750 … picture;

751 … real-time display of regions; 755 … List display area; e … eye under examination;

OS1 … viewing optics; OS2 … optotype optical system; OS3 … alignment detection optics;

An OS4 … ocular refractive power measurement optical system; OS41 … projects light optics;

OS42 … receives optical system

Detailed Description

Embodiments exemplified by the present disclosure will be described below with reference to the drawings.

The measurement apparatus 1 of the present embodiment shown in fig. 1 is an eye refractive power measurement apparatus. The measurement apparatus 1 projects measurement light toward the fundus of the eye E through the window W. And receives reflected light from the fundus corresponding to the measurement light. The refractive power of the eye E to be examined (hereinafter also referred to as eye refractive power) is measured based on the light reception signal.

as shown in fig. 1, the measuring device 1 has an optical system 3 and a control system 7 of the device. The optical system 3 of the apparatus has an observation optical system OS1, a sighting mark optical system OS2, an alignment detection optical system OS3, and an eye refractive power measurement optical system OS 4.

The observation optical system OS1 is provided for observing the anterior segment of the eye E. The optotype optical system OS2 is arranged for presenting optotypes 24. The alignment detection optical system OS3 is provided for detecting the position of the eye E to be examined relative to the optical system 3 of the apparatus. The eye power measurement optical system OS4 is provided for measuring the power of the eye E to be examined.

the observation optical system OS1 mainly includes: illumination light sources 11, 12; a lens 14; a heat reflecting mirror 16, a lens 18; and an observation image pickup device 20. The illumination light sources 11 and 12 are configured to emit infrared light having a wavelength of 780nm, for example. The heat reflecting mirror 16 is configured to transmit infrared light from the illumination light sources 11 and 12 through the heat reflecting mirror 16. The heat mirror 16 is also configured to reflect light from the alignment light source 34, the measurement light source 40, and the sighting mark light source 22.

In the observation optical system OS1, the infrared light irradiated by the illumination light sources 11 and 12 and reflected at the anterior eye portion of the eye E is guided onto the observation image pickup device 20 via the lens 14, the heat mirror 16, and the lens 18.

the optotype optical system OS2 mainly includes: a target light source 22, a target 24, a lens 26, a half mirror 28, a mirror 30, a heat mirror 32, a heat mirror 16, and a lens 14. As can be seen from this description, optotype optical system OS2 includes several optical components in common with observation optical system OS 1.

The sighting mark light source 22 is configured to irradiate visible light with a wavelength of 400-700 nm, for example. The optotype 24 is configured to be movable in the optical axis direction. The movement of the optotype 24 is controlled by the control system 7.

the half mirror 28 is configured to transmit light from the optotype light source 22 through the half mirror 28 and reflect light from the alignment light source 34. The heat mirror 32 is configured to transmit the light from the sighting mark light source 22 and the alignment light source 34 through the heat mirror 32 and to reflect the light from the measurement light source 40.

In the optotype optical system OS2, light emitted from the optotype light source 22 passes through the optotype 24, passes through the lens 26 and the half mirror 28, and is reflected by the mirror 30. Then, the light reflected by the mirror 30 is transmitted through the heat mirror 32 and reflected at the heat mirror 16, and then irradiated to the eye E via the lens 14.

the alignment detection optical system OS3 mainly includes: alignment light source 34, half mirror 28, mirror 30, heat mirror 32, heat mirror 16, lens 14, and alignment detection sensors 36, 38 (in other words, profile sensors).

the alignment light source 34 is configured to irradiate infrared light having a wavelength of 810nm, for example. Light from the aiming light source 34 is reflected at the half mirror 28 and reflected at the mirror 30. The reflected light is transmitted through the heat mirror 32, reflected by the heat mirror 16, and then irradiated to the eye E via the lens 14. The illumination light is reflected at the cornea of the eye E and guided to the alignment detection sensors 36, 38.

The ophthalmic refractive power measurement optical system OS4 includes: a projection light optical system OS41 and a reception light optical system OS 42. The projection light optical system OS41 mainly includes: a measurement light source 40, a lens 42, a reflector 44, a perforated mirror 46, a parallel plane plate 48, a heat mirror 32, a heat mirror 16, and a lens 14.

The receiving optical system OS42 mainly includes: a lens 50, a ring lens 52, a measurement image pickup element 54, and optical components common to the projection light optical system OS 41. The common optical components are: lens 14, heat mirror 16, heat mirror 32, parallel plane plate 48, and perforated mirror 46.

The measurement light source 40 is constituted by, for example, a superluminescent diode (SLD) having high interference. The measuring light source 40 is configured to emit infrared light having a wavelength of 880nm, for example, as a measuring beam. The measurement imaging element 54 is configured to be movable in the optical axis direction. The control system 7 controls the movement of the measurement imaging element 54.

The parallel plane plate 48 is disposed on an optical path shared by the projection light optical system OS41 and the reception light optical system OS 42. Specifically, the parallel plane plate 48 is inclined so that the measuring beam enters a position at a predetermined distance from the pupil center of the eye E, and the parallel plane plate 48 is disposed so as to rotate around the optical axis of the common optical path in the inclined state. The rotation of the parallel plane plate 48 is controlled by the control system 7. The measuring beam is rotated circumferentially on the pupil of the eye E by rotation of the parallel plane plate 48. This rotation can suppress speckle noise generated by using a light source having high interference. The parallel plane plate 48 is disposed at a position conjugate to the pupil of the eye E, for example.

The light beam from the measurement light source 40 is reflected at the mirror 44 via the lens 42, and is reflected at the heat mirror 32 and the heat mirror 16 through the hole of the central portion of the perforated mirror 46 and the parallel flat plate 48. The light beam reflected by the heat mirror 16 is irradiated to the fundus of the eye E via the lens 14. The light beam reflected by the fundus of the eye E to be inspected is reflected at the heat mirror 16 and the heat mirror 32 via the lens 14 and passes through the parallel plane plate 48. The light flux having passed through the parallel plane plate 48 is reflected by the annular lens portion of the perforated mirror 46, and then guided to the measurement image pickup device 54 via the lens 50 and the annular lens 52.

The optical system 3 of the apparatus having the above-described structure is arranged so that the whole thereof can be displaced in the XYZ direction. The displacement of the optical system 3 of the device is controlled by a control system 7. The displacement is performed in order to align the eye E to be examined with the position of the optical system 3 of the device. The X direction described herein corresponds to the left-right direction, the Y direction corresponds to the up-down direction, the Z direction corresponds to the front-back direction, and the front-back direction corresponds to the optical axis direction.

As shown in fig. 2, the control system 7 includes a 1 st driving device 61, a 2 nd driving device 62, a 3 rd driving device 63, a 4 th driving device 64, a control device 70, a display 75, and an input interface 79.

The 1 st driving device 61 is configured such that the 1 st driving device 61 is controlled by the control device 70 to move the optotype 24 in the optical axis direction. The 2 nd driving device 62 is configured such that the controller 70 controls the 2 nd driving device 62 to rotate the parallel plane plate 48 around the optical axis center.

The 3 rd driving device 63 is configured such that the control device 70 controls the 3 rd driving device 63 to move the measurement imaging element 54 in the optical axis direction. The 4 th driving device 64 is configured such that the 4 th driving device 64 is controlled by the control device 70 to move the optical system 3 of the apparatus in the XYZ-direction.

The 1 st driving device 61, the 2 nd driving device 62, the 3 rd driving device 63, the 4 th driving device 64, the display 75, the input interface 79, the observation imaging device 20, the alignment detection sensors 36 and 38, and the measurement imaging device 54 are connected to the control device 70.

The control device 70 has a processor 71 and a memory 73. The memory 73 includes ROM, RAM, and flash memory. The processor 71 performs a process of controlling the measuring apparatus 1 in accordance with a computer program recorded in the memory 73 to realize various functions.

the display 75 has, for example, a Liquid Crystal Display (LCD). The display 75 is controlled by the control device 70 to display various information to the examiner. The input interface 79 has an operation lever and a key switch for the examiner to operate the measurement apparatus 1. The input interface 79 functions as an input unit or an operation unit. The input interface 79 inputs a command signal from the examiner to the control device 70.

Although not shown, the control system 7 may further include a printing device for providing the measurement result to the inspector as a printed matter. The control system 7 may also have data communication means for providing measurement results to an external information processing device.

A video signal representing a captured image of the anterior segment is input from the observation imaging device 20 to the control device 70. The control device 70 displays the image of the anterior segment on the display 75 based on the video signal (see fig. 7).

Further, detection signals are also input from the alignment detection sensors 36, 38 to the control device 70. The detection signal indicates the received light distribution of the cornea reflected light (light spot) received by the alignment detection sensors 36, 38.

The control device 70 calculates three-dimensional position coordinates (i.e., XYZ position coordinates) of the eye E to be inspected with respect to the optical system 3 of the apparatus as an alignment index based on the detection signals from the alignment detection sensors 36, 38. The control device 70 controls the 4 th driving device 64 based on the alignment index as necessary, thereby performing alignment between the optical system 3 of the apparatus and the eye E.

Further, a light reception signal of the annular image formed on the measurement image pickup element 54, that is, a light reception signal of the annular image corresponding to the measurement light beam reflected by the fundus of the eye E to be inspected is also input from the measurement image pickup element 54 to the control device 70. The control device 70 measures the refractive power of the eye E from the annular image represented by the light reception signal.

Specifically, the control device 70 detects the coordinates of the ring image. The control device 70 performs ellipse fitting on the annular image by the least square method or the like based on the detected position coordinates of the annular image. The control device 70 calculates refractive values of S (sphere power), C (astigmatism power), and a (axis angle of astigmatism) as measured values relating to the refractive power of the eye E from the fitted elliptical shape. The control device 70 displays the calculated measurement value of the eye E on the display 75. The control device 70 stores the measurement value as historical measurement data in the memory 73.

in order to provide the measurement results to the examiner, for example, upon request from the examiner after the examination is finished, the historical measurement data is stored in the memory 73, particularly, in the flash memory. For example, the history measurement data is stored, presented to the examiner as a printed matter, or transferred to an external information processing apparatus.

Next, details of processing performed by the control device 70 to measure the eye refractive power will be described. The control device 70 is configured to repeatedly execute the main control process shown in fig. 3. In the main control process, the control device 70 waits until the examiner inputs a start instruction through the input interface 79 (S110). When the start command is input (S110: yes), the control device 70 determines whether or not the measurement mode selected from the plurality of measurement modes is the continuous measurement mode (S120).

The control device 70 can receive an operation designated by the examiner for the measurement mode via the input interface 79 by displaying a graphical user interface for mode selection on the display 75.

If the control device 70 determines that the designated measurement mode is not the continuous measurement mode (S120: no), the first measurement process corresponding to the normal measurement mode is executed (S130). If the control device 70 determines that the designated measurement mode is the continuous measurement mode (yes in S120), the second measurement process corresponding to the continuous measurement mode is executed (S140). After that, the main control process is ended.

In the first measurement process (S130), the control device 70 measures the refractive power of the eye E after performing the automatic fogging.

As shown in fig. 4, when the control device 70 starts the first measurement process, the refractive power of the eye E is pre-measured (S210). In the pre-measurement, the refractive power of the eye E is measured to appropriately form the fogging state. Specifically, the control device 70 controls the 4 th driving device 64 based on the alignment index, thereby adjusting the position of the optical system 3 of the apparatus in the XYZ direction with respect to the eye E. I.e. the position of the optical system 3 of the alignment device and the eye E to be examined.

Then, the control device 70 lights up the measurement light source 40, and projects a spot-like point light source image onto the fundus of the eye E while rotating the parallel flat plate 48. The point light source image projected on the fundus is reflected and formed into a ring shape on the measurement imaging device 54 by the ring lens 52. At this time, the control device 70 moves the measurement image pickup element 54 in the optical axis direction to form the finest and brightest annular image on the measurement image pickup element 54. Then, the control device 70 predicts the refractive power of the eye E from the annular image.

After the end of the pre-measurement (S210), the control device 70 executes the automatic fogging based on the measured value of the refractive power obtained by the pre-measurement (S220). That is, the control device 70 moves the optotype 24 in the optical axis direction, thereby positioning the optotype 24 at a position conjugate to the fundus of the eye E. Then, the control device 70 moves the optotype 24 by a distance corresponding to the appropriate diopter to form the foggy state of the optotype 24 with respect to the eye E (S220).

the control device 70 performs main measurement in the foggy state (S230). That is, the control device 70 turns on the measurement light source 40 and forms an annular image on the measurement imaging element 54, as in the case of the pre-measurement. The refractive power of the eye E is measured based on the light reception signal of the measurement imaging device 54.

Then, the control device 70 displays the measurement value of the refractive power on the display 75, and saves the measurement value as historical measurement data in the memory 73 (S240). After that, the first measurement process is ended (S130).

In the second measurement process (S140) shown in fig. 5, the control device 70 continuously measures the refractive power of the eye E without performing pre-measurement and automatic fogging. When the control device 70 starts the second measurement process, the refractive power of the eye E is not measured by the pre-measurement, and the optotype 24 and the measurement imaging element 54 are fixed at the standard positions without performing the automatic fog vision based on the measured values (S310). The standard position is a predetermined position.

According to another example, the control device 70 may fix the optotype 24 and the measurement imaging device 54 at positions designated by the examiner through the input interface 79 instead of the standard positions. The control device 70 may control the 4 th driving device 64 to place the optical system 3 of the apparatus at a standard position or at a position designated by the examiner through the input interface 79.

Thereafter, the control device 70 repeatedly and continuously executes the repeated measurement processing shown in fig. 6 (S320) until the examiner inputs an end instruction through the input interface 79. If an end instruction is input (S330: yes), the control device 70 ends the second measurement process, and thus ends the continuous measurement of refractive power.

When the repetition of the measurement process is started, the control device 70 acquires a ring image (S410). That is, the control device 70 lights the measurement light source 40 to form an annular image on the measurement image pickup element 54. Then, the control device 70 acquires a light reception signal of the measurement image pickup device 54 indicating the ring image from the measurement image pickup device 54.

Further, the control device 70 acquires an alignment index of the eye E when the annular image is formed (S420). In S420, the control device 70 acquires detection signals of the alignment detection sensors 36, 38. And, the control device 70 calculates, as an alignment index, three-dimensional position coordinates of the eye E with respect to the optical system 3 of the apparatus based on the detection signal.

Then, the control device 70 calculates a measured value of refractive power from the annular image indicated by the light reception signal acquired in S410 (S430). The measured values include refractive values of S (sphere power), C (astigmatism power), and a (astigmatism axis angle) associated with the eye E to be examined.

Further, the control device 70 calculates the reliability of the latest measurement value calculated in S430 (S440). The calculated reliability may be any one of the following scores Z1, Z2, Z3, Z4, or may be a weighted sum of two or more of the scores Z1, Z2, Z3, Z4.

the fraction Z1 is a fraction based on the alignment error between the eye E to be examined and the optical system 3 of the device. The alignment error may be calculated as an error D (dX, dY, dZ) between the three-dimensional position coordinate P of the eye E with respect to the optical system 3 of the apparatus (X, Y, Z) and the reference position P0 (X0, Y0, Z0) P-P0. The score Z1 is defined such that the larger the alignment error (absolute value), the smaller the value displayed by the score Z1; and the smaller the alignment error, the larger the value displayed by the score Z1. For example, the fraction Z1 may be a value calculated by the formula Z1 ═ D | to which a negative sign is added before the alignment error (absolute value).

The score Z2 is a score based on the amount of missing of the ring image received by the measurement image pickup element 54. The shortage corresponds to an error between the number of points constituting the ring image detected by the measurement image pickup element 54 and a theoretical value. The score Z2 is defined such that the larger the deficiency, the smaller the value displayed by the score Z2; the smaller the deficiency amount, the larger the value shown by the score Z2.

The score Z3 is a score based on the magnitude of distortion of the ring image detected by the measurement image pickup element 54. The magnitude of the distortion corresponds to the error between the annular image and the theoretical shape. The score Z3 is defined such that the larger the distortion, the smaller the value displayed by the score Z3; and the smaller the distortion, the larger the value displayed by the score Z3.

The score Z4 is a score based on the difference between the measured value and the average value or the difference between the measured value and the central value. The score Z4 is defined such that the larger the difference, the smaller the value displayed by the score Z4; and the smaller the difference, the larger the score Z4 shows. In the continuous measurement of refractive power, the fraction Z4 can be calculated after a predetermined number or more of measured values are obtained.

Then, the control device 70 determines the display color of the measured value as the color corresponding to the calculated reliability (S450). For example, the control device 70 determines which of the "high", "medium", and "low" criteria the reliability of the measured value is in, in accordance with a predetermined criterion.

when the reliability is "low", the control device 70 determines the display color as the 1 st color (for example, "red"). When the reliability is "medium", the control device 70 determines the display color to be the 2 nd color (for example, "white") different from the 1 st color. When the reliability is "high", the control device 70 determines the display color as the 3 rd color (for example, "blue") different from both the 1 st color and the 2 nd color.

After that, the control device 70 displays the latest refractive power measurement value calculated in S430 in the color determined in S450 on the real-time display region 751 of the display 75 (S460). The reliability of the latest measurement value is thereby displayed on the display 75 as color information together with the measurement value.

In the second measurement process, control device 70 may display screen 750 shown in fig. 7 on display 75. This screen 750 includes a real-time display region 751, an operation object display region 753, and a list display region 755.

By controlling the display 75 by the control device 70, the latest photographed image (live view image) of the anterior segment of the eye E and the latest refractive power measurement value are displayed in the live view display region 751 together. When the last measurement value is displayed on the real-time display region 751, the control device 70 may control the display 75 to display the latest measurement value on the real-time display region 751 instead of the last measurement value (S460).

A graphical user interface including a plurality of operation objects is displayed in the operation object display region 753. A plurality of measurement values obtained by continuous measurement are displayed in a list in the list display area 755. Specifically, the measured values with the reliability equal to or higher than the reference are displayed in a list in the list display area 755.

The control device 70 determines whether or not the reliability of the latest measurement value is equal to or higher than a reference (S470). When the reliability is judged to be equal to or higher than the reference level (S470: YES), the list update process shown in FIG. 8 is executed (S480). As a result, the measurement values with reliability equal to or higher than the reference value, including the latest measurement value, are displayed in a list in the list display area 755.

When it is judged that the reliability is less than the reference (S470: no), the control device 70 does not additionally display the latest measurement value in the list display area 755, but ends the iterative measurement process. If no termination command is input from the examiner (no in S330), the control device 70 executes the repeated measurement process again (S320).

Next, details of the list update processing executed by the control device 70 in S480 will be described with reference to fig. 8. When the list update process is started, control device 70 determines whether or not there is a free area for adding and displaying the latest measurement value in list display area 755 (S510). If it is determined that there is a free area (yes in S510), control device 70 executes the process of S530.

If it is determined that there is no free area (S510: no), the control device 70 deletes the measurement value with the lowest reliability among the measurement value groups displayed in the list display area 755, that is, deletes the measurement value with the lowest reliability in the measurement value list, from the list display area 755 (S520). When there are a plurality of measurement values with the lowest reliability, the control device 70 deletes the measurement value with the lowest reliability and the oldest measurement value from the list display area 755 (S520). The process of S530 is then executed.

In S530, the control device 70 additionally displays the latest measurement value in the list display area 755. The control device 70 may additionally display the measurement value in the list display area 755 in the color corresponding to the reliability determined in S450. In one example, a plurality of measurement values including the latest measurement value are arranged in time series and displayed in a list in the list display area 755.

The control device 70 may execute the process of S535 instead of the process of S530. In S535, the control device 70 adds and displays the latest measurement values to the list display area 755 so that the measurement values are arranged in order of reliability and displayed in a list.

Then, the control device 70 saves the measurement values additionally displayed in the list display area 755 in the memory 73 as the historical measurement data (S540), and ends the list update process (S480).

According to the second measurement processing, the refractive power of the eye E is continuously measured. Also, as shown in fig. 9, when each measurement is finished, the latest measurement value is displayed in the real-time display region 751 in a color corresponding to the reliability. This allows the information on the reliability to be displayed on the display 75 in real time together with the latest measured value.

When the reliability is equal to or higher than the reference level, the latest measurement value is displayed in the list display area 755 in addition, and the latest measurement value and the old measurement values with the reliability equal to or higher than the reference level are displayed in a list on the display 75. According to the example of fig. 9, the reliability being more than the reference corresponds to the reliability being more than "medium".

The measurement device 1 of the present embodiment described above is effective in that it is provided with a continuous measurement mode for measuring the eye E of a restless subject, particularly a child.

In measuring the refractive power of the eye, automatic fogging is preferably performed to relax the eye E to be examined. However, for a person who is restless, it is difficult or time-consuming to properly perform automatic fogging because the alignment state between the eye E and the optical system 3 of the device is unstable. Compared with a stable adult, the effect of automatic fog vision is not good. Also, the longer the measurement time is dragged, the less the child is engaged in the measurement.

In view of the above, in the continuous measurement mode (second measurement processing), continuous measurement of refractive power is promptly started without performing the pre-measurement and the automatic fogging from the time when the examiner inputs the start command through the input interface 79 to the time when the examiner inputs the end command. By this continuous measurement, the number of times of measurement per unit time can be increased, and more measurement values with higher reliability measured in an accurate alignment state can be acquired in a short time.

according to the measuring apparatus 1 of the present embodiment, it is also effective to sequentially display the measurement values of each measurement on the display 75 at the end of each measurement in the process of continuous measurement. At this time, the measurement value is displayed on the display 75 in a display form corresponding to the reliability, specifically, in a color corresponding to the reliability. Thereby, the information of the reliability is displayed on the display 75 together with the measured value.

Therefore, the inspector can reliably grasp the situation as to whether or not accurate measurement is being performed based on the display information of the display 75. By grasping the situation, the examiner can appropriately cope with the situation, and can complete an appropriate examination in a short time. Specifically, the measurement apparatus 1 can be caused to continuously perform the continuous measurement until a desired measurement result is obtained, and in the case where the desired measurement result is obtained, an end instruction can be input and the continuous measurement can be ended promptly.

In the present embodiment, many measurement values can be obtained in a short time by continuous measurement without performing automatic fogging. Moreover, by displaying the measured value and the reliability in real time, an inspector can easily master whether accurate measurement is carried out or not in the continuous measurement process. Therefore, the measuring instrument 1 of the present embodiment is sufficiently suitable for a highly mobile subject.

In particular, in the present embodiment, since the measurement values with high reliability are also displayed in the list display area 755, the examiner can grasp the situation of the eye examination by the continuous measurement.

In the present embodiment, when the list of measurement values displayed on the screen 750 is full, the measurement values with low reliability and the older measurement values are preferentially deleted from the list so as to keep information having value for the examiner as much as possible in the list.

Therefore, in the present embodiment, the measurement information of the refractive power required by the examiner can be displayed in a list in a clear and understandable manner. In particular, according to the example (S535) in which the measurement values are sequentially displayed in the list display area 755 in a list according to the reliability, information required by the examiner can be provided more clearly and easily.

In one example, the reliability is determined based on the position of the eye E and the spatial distribution of the reflected light. Specifically, the reliability is determined based on the alignment error of the eye E, the amount of missing annular image, and the magnitude of distortion. With this configuration, the reliability can be determined more accurately.

In the present embodiment, the continuous measurement mode and the normal measurement mode are switched and executed based on an instruction from the examiner. According to the above switching of the modes, more appropriate refractive power measurement can be performed for children and adults, respectively. Therefore, according to the present embodiment, an ophthalmic refractive power measurement apparatus with higher convenience can be provided.

The present disclosure is not limited to the above embodiments, and various embodiments can be adopted. In the above embodiment, the continuous measurement is ended based on the end instruction of the examiner from the input interface 79. However, the control device 70 may be operated to terminate the continuous measurement without receiving a termination command. For example, the control device 70 may be operated to terminate the continuous measurement on the condition that a predetermined number of measured values based on the reliability or more are obtained after the continuous measurement is started.

The measured values with reliability less than the reference may also be displayed in the list display area 755. When the display area of the display 75 is small, it is also conceivable not to provide the list display area 755.

That is, the measurement device 1 may be configured to display the measurement values in real time, but not to display a list. In this case, the measuring apparatus 1 may store the measured value for each time in the memory 73, and provide a list of the measured values to the examiner together with information of reliability in the form of, for example, a print after the examination is finished. The list of the measured values may be supplied as digital data from the measuring device 1 to an external information processing apparatus.

The measuring instrument 1 may be configured to display the 1 st screen on the display 75 when continuous measurement is performed, and to display the 2 nd screen on the display 75 after the continuous measurement is completed. The 1 st screen is not provided with the list display area 755 but is constituted by the real-time display area 751. The 2 nd screen is composed of a list display area 755 instead of the real-time display area 751. That is, the measuring instrument 1 may be configured to display a list of the measured values on the display 75 only after the end of the continuous measurement.

The processes performed by the control device 70 may be performed out of the order described. The execution order of the plurality of steps that can produce the same result even if the execution order is changed is not limited to the order described above. Several steps may also be performed concurrently.

for example, the control device 70 may be configured to concurrently execute a process of acquiring a light reception signal from the measurement image pickup device 54 and calculating a measurement value of refractive power, and a process of calculating an alignment index based on detection signals from the alignment detection sensors 36 and 38. In this case, in order to calculate the alignment index at the time of measurement with good accuracy, the alignment detection sensors 36 and 38 may perform the detection operation at a cycle shorter than that of the imaging operation performed by the measurement imaging element 54.

The control device 70 may repeatedly calculate the alignment index at a cycle shorter than the cycle of calculating the measurement value of the refractive power. For example, the control device 70 may calculate the measurement value of the refractive power at a cycle of about 200 milliseconds, and calculate the alignment index at a cycle of about 20 milliseconds.

The measurement device 1 may be configured to be capable of simultaneously measuring the refractive powers of both eyes of the examinee or capable of switching the measurement of the refractive powers of both eyes of the examinee in accordance with an instruction of the examinee. Therefore, the measuring instrument 1 may have a multiple structure corresponding to at least a part of the optical system 3 and the control system 7 of the instrument corresponding to the left and right eyes. In this case, the measurement values of the refractive powers of the left and right eyes may be displayed on the display 75 in at least one of a real-time display and a list display.

The measuring apparatus 1 may be configured to automatically switch the measurement mode from the normal measurement mode to the continuous measurement mode when a specific condition is satisfied after the start of the operation in the normal measurement mode.

For example, the control device 70 may be configured to repeat the mode switching process shown in fig. 10 concurrently during execution of the first measurement process (S130), continue execution of the first measurement process when the specific condition is not met (S610: no), and interrupt the first measurement process (S620) and start execution of the second measurement process (S630) when the specific condition is met (S610: yes). The specific condition may be a condition based on the occurrence of a failure in measurement and/or a condition based on the reliability of the measurement value.

For example, the measurement device 1 may be configured to automatically switch the measurement mode to the continuous measurement mode when a measurement failure occurs a plurality of times in succession in the normal measurement mode. The measuring instrument 1 may be configured to automatically switch the measurement mode to the continuous measurement mode when only a measurement value having a reliability lower than a predetermined standard (for example, a measurement value having a reliability of "low") is obtained.

Alternatively, the measuring instrument 1 may be configured such that information for advising switching to the continuous measurement mode, such as "whether or not to switch to the continuous measurement mode?", is displayed on the display 75, and then the measuring instrument 1 can switch the measurement mode from the normal measurement mode to the continuous measurement mode in accordance with an instruction from the examiner.

In addition, the functions of 1 component element in the above embodiment may be provided dispersed among a plurality of component elements. The functions possessed by the plurality of constituent elements may be integrated into 1 constituent element. A part of the configuration of the above-described embodiment may be omitted. All aspects included in the technical idea defined by the terms described in the claims are embodiments of the present disclosure.

Finally, the correspondence between the terms is explained. The projection light optical system OS41 corresponds to an example of the light projection unit; the light receiving optical system OS42 corresponds to an example of a light receiving unit, and the alignment detection optical system OS3 corresponds to an example of a detection unit. The input interface 79 corresponds to an example of an input unit.