CN217285744U - Eye axis length measuring system - Google Patents

Abstract

The utility model discloses an axis length measuring system, including SLD light source, sample arm, reference arm, coupler and photoelectric sensor, the coupler is used for dividing the light that the SLD light source produced into two tunnel, and handles in reference arm and sample arm respectively to and export to photoelectric sensor after carrying out optical modulation with the reverberation that reference arm and sample arm original route were returned; the sample arm comprises a first collimating mirror and a low-pass reflector, the first collimating mirror is used for collimating the light from the coupler into collimated light, and the collimated light enters the fundus after being reflected by the low-pass reflector; and a flat glass which can rotate and allow light rays to pass through is obliquely arranged between the first collimating mirror and the low-pass reflector and is close to the first collimating mirror. The irradiation range of the collimated light around human eyes is enlarged, and the required data can be captured more conveniently.

Description

System for measuring eye axis length

Technical Field

The utility model relates to an ophthalmology equipment, in particular to long measurement system of eye axis.

Background

The eye axis length measuring instrument is usually used for measuring the thickness of each layer of an eyeball from a cornea to an eyeground, assisting in measuring the corneal curvature and the pupil size, even scanning and measuring the eyeball to establish a three-dimensional model thereof, and obtaining a complete eyeball data simulation structure.

The traditional eye axis length measuring system comprises an SLD light source, a sample arm, a reference arm, a coupler and a photoelectric sensor,

the coupler is used for dividing light generated by the SLD light source into two paths, respectively processing the two paths in the reference arm and the sample arm, and outputting reflected light returned by the original paths of the reference arm and the sample arm to the photoelectric sensor after optical modulation;

the sample arm comprises a first collimating mirror and a low-pass reflector, the first collimating mirror is used for collimating light from the coupler into collimated light, and the collimated light enters the fundus after being reflected by the low-pass reflector.

The reference arm comprises a second collimating mirror, two pyramid prisms and a reflector, light rays coming out of the coupler are collimated into collimated light rays through the second collimating mirror and then reach the reflector after passing through the two pyramid prisms, and the light rays reflected by the reflector return to the coupler in the original path.

Since the human eye always has a slight jitter in a time frame, it is difficult to fix completely. And because the visual axis and the optical axis of the eyeball of a person have a certain angle of declination, if the light rays emitted into the eye are perpendicular to the position of the fundus macula lutea according to the visual axis, the light rays are certainly not perpendicular to the eyeball, the reflected light rays on the surface of the crystal also have a declination, and the reflected light rays are collected to cause great difficulty, namely the light rays are difficult to enter the original emission point.

SUMMERY OF THE UTILITY MODEL

To the prior art problem, the utility model provides an axis of eye length measurement system enlarges the irradiation range of collimated light around people's eye, more conveniently snatchs the data of needs.

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes: an eye axis length measuring system comprises an SLD light source, a sample arm, a reference arm, a coupler and a photoelectric sensor,

the coupler is used for dividing light generated by the SLD light source into two paths, processing the two paths in the reference arm and the sample arm respectively, and outputting reflected light returned by the original paths of the reference arm and the sample arm to the photoelectric sensor after optical modulation;

the sample arm comprises a first collimating mirror and a low-pass reflector, the first collimating mirror is used for collimating light coming out of the coupler into collimated light, the collimated light enters the fundus after being reflected by the low-pass reflector, and plate glass which can rotate and can be penetrated by the light is obliquely arranged between the first collimating mirror and the low-pass reflector and is close to the first collimating mirror.

Meaning that light passes through the plate glass and the surface of the plate glass is not perpendicular to the optical axis direction. The plate glass is driven to rotate by a motor and a gear mechanism, and the mechanism is a conventional rotating mechanism. The rotating glass plate is set to allow the parallel collimated light to pass through the rotating glass plate, so that the light passing through the glass plate moves in a circular motion. The light entering the eyes can shake in a larger range, and the required data can be grasped more conveniently.

That is, the plate glass at the inclination rotates at a high speed under the driving of the motor, so that the collimated linear light beam moves in a winding manner, and the winding range covers a certain range around the eye axis, thereby more conveniently collecting the reflected light and entering the original emission point, and more conveniently capturing the required data.

The utility model discloses a distance of this piece in each surface of eyeball is measured to OCT optics principle. The light emitted by the SLD light source enters the sample arm through the coupler and is collimated into collimated light through the collimating mirror. Then enters the eyes after being reflected by a low-pass reflector. The light is reflected back on each surface up into the coupler. The light emitted by the light source SLD passes through the coupler, the other part of the light enters the reference arm, the light of the reference arm returns to the coupler after being reflected by the reflector on the reference arm, and the two paths of light are output from the output end in the coupler and reach the photoelectric sensor. The signals are processed to obtain the information collected by the light of the sample arm on each surface of the eye, namely the thickness of each surface, namely the principle of measuring the axial length of the eye.

In the scheme, the optical imaging device further comprises a Placido disc surface, an imaging mirror group and a cornea eye ground graph acquisition device, wherein a central hole is formed in the center of the Placido disc surface, a plurality of circles of light rings are arranged on the Placido disc surface, light emitted by the light rings of the Placido disc surface irradiates the eye ground, the light enters the low-pass reflector after being reflected, and the light penetrating through the low-pass reflector enters the imaging mirror group and then enters the cornea eye ground graph acquisition device.

Preferably: the first large objective lens of the imaging lens group is positioned in a central hole of the Placido plate surface.

The Placido plate surface is provided with a hole at the center for light and lenses to penetrate.

Measurements of corneal curvature and corneal topography can be achieved. The schematic diagram of measuring the corneal curvature is shown in fig. 2, and a halo (object point) of a point A on the Placido disc surface irradiates on the cornea, is reflected by the cornea and then is imaged on a corneal fundus graph acquisition device through an optical system. According to the image point distribution on the cornea fundus graph acquisition device, the curvature of the cornea and other characteristics can be calculated.

The corneal fundus graph is measured as shown in fig. 4, and a plurality of circles of lighted standard apertures, a, B,. are imaged on a corneal fundus graph acquisition device after passing through an optical system of the map, and the A, B,. correspond to the A', B.

After the cornea fundus graph collecting device collects the multiple circles of annular images, standard cornea curvature data are compared, and actually measured cornea surface data can be obtained through comparison. This calculation method is prior art.

In the above scheme, the first large objective lens of the imaging lens group is located in the central hole of the Placido plate surface. By adopting the structural design, the imaging optical system is not placed behind the Placido disc surface, so that the functions are realized, the structure is compact, and the corneal base profile measurement and the corneal curvature measurement can be taken into consideration.

The utility model discloses a Placido quotation design has following benefit on eye axle length measurement system's the main beam axis:

when measuring the corneal fundus image, the position of the patient (i.e. the eye to be measured) needs to be exactly the same as the machine placement position, which is called "alignment". In the prior art, a light emitting device and a receiving device are additionally arranged on the left side and the right side of a machine, and whether the alignment is ideal or not is judged by sensing the position of corneal reflection light. And the utility model discloses with Placido quotation design on eye axle length measurement system's main optical axis, both can realize cornea curvature radius's measurement, simultaneously, in eye axle length measurement, realized counterpointing, and counterpoint the accuracy. That is to say, when the measurement is performed by using the OCT light (the above-mentioned function of measuring the length of the eye axis), the light incident on the eye surface coinciding with the central optical axis is used to measure the interference signals on each surface of the eye until the parameters of the eye can be measured, and on the premise that the measurement is accurate, that is, when the length of the eye axis is measured, the alignment is already performed, and when the length of the eye axis is measured, the alignment is required to be very accurate, which is far more reliable than the conventional method that only the reflected light from the eye surface is used as the basis for determining the alignment! And is more accurate.

In the scheme, the method comprises the following steps: the cornea fundus graph acquisition device is a CCD.

In the scheme, the method comprises the following steps: the reference arm comprises a second collimating mirror, two pyramid prisms and a reflector, light rays coming out of the coupler are collimated into collimated light rays through the second collimating mirror and then reach the reflector after passing through the two pyramid prisms, and the light rays reflected by the reflector return to the coupler in the original path.

In the scheme, the method comprises the following steps: the inclination angle of the plate glass is 1-5 degrees.

Has the advantages that: the utility model discloses a position slope that is close to first collimating mirror between first collimating mirror and low pass reflector is provided with the plate glass that can the rotatory confession light pass for the straight line light beam after the collimation is the motion of winding, thereby makes the winding scope cover the certain scope of eye axle periphery, thereby more conveniently grabs the data that remove needs.

Drawings

Fig. 1 is a schematic view of the optical structure of the present invention.

Fig. 2 is a schematic diagram of corneal radius of curvature measurement.

Fig. 3 is a schematic diagram of a corneal topography measurement system.

Fig. 4 is a schematic diagram of a conventional alignment method.

Detailed Description

The present invention will be further described with reference to the following examples and accompanying drawings.

Example 1

As shown in fig. 1-3, the eye axis length measuring system of the embodiment of the present invention includes an SLD light source 1, a sample arm, a reference arm, a coupler 2, and a photosensor 3.

The coupler 2 is used for dividing the light generated by the SLD light source 1 into two paths, processing the two paths in the reference arm and the sample arm respectively, and outputting the reflected light returned by the original paths of the reference arm and the sample arm to the photoelectric sensor 3 after optical modulation.

The sample arm comprises a first collimating mirror 4 and a low-pass reflector 5, the first collimating mirror 4 is used for collimating the light coming out of the coupler 2 into collimated light, and the collimated light enters the fundus after being reflected by the low-pass reflector 5.

The reference arm comprises a second collimating mirror 6, two pyramid prisms 7 and a reflector 8, light rays coming out of the coupler 2 are collimated into collimated light rays through the second collimating mirror 6, then reach the reflector 8 after passing through the two pyramid prisms 7, and return to the coupler 3 in the original path after being reflected by the reflector 8.

A flat glass 11 which can rotate and allow light to pass through is obliquely arranged between the first collimating mirror 4 and the low-pass reflecting mirror 5 and is close to the first collimating mirror 4, and the inclination angle of the flat glass 11 is 1-5 degrees.

The center of Placido quotation 8 is equipped with the centre bore, is provided with many circles of light rings on Placido quotation 8 from outside to inside, and Placido quotation 8's structure is prior art, and the light that the light ring of Placido quotation launches out shines the eye ground, gets into low pass mirror 5 after the reflection, and the light that passes low pass mirror 5 gets into imaging mirror group 9, then gets into cornea eye ground figure collection system 10. The first large objective lens of the imaging lens group 9 is located in the central hole of Placido plate surface 8.

Fig. 1-2 are schematic diagrams of corneal curvature measurement: a point A on the Placido disc surface represents a circle of light rings (object points), irradiates the cornea, is reflected by the cornea and then is imaged on the cornea fundus graph acquisition device 10 through an optical system. According to the image point distribution on the cornea fundus graph acquisition device 10, the curvature of the cornea and other characteristics can be calculated.

In FIG. 2, when b > r, it can be seen that:

as shown in fig. 3, a plurality of circles of lighted standard apertures, a, B, are formed on the Placido disc surface, and are imaged on a corneal fundus pattern collecting device after passing through the optical system of the upper drawing, wherein the standard apertures correspond to the standard apertures, a, B, a.

After the cornea fundus graph acquisition device collects the plurality of circles of annular images, the standard cornea curvature data are compared, and the actually measured cornea surface data can be obtained through comparison. This calculation method is prior art.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents as used in the actual practice.

Claims (6)

1. An eye axis length measuring system comprises an SLD light source, a sample arm, a reference arm, a coupler and a photoelectric sensor,

the coupler is used for dividing light generated by the SLD light source into two paths, processing the two paths in the reference arm and the sample arm respectively, and outputting reflected light returned by the original paths of the reference arm and the sample arm to the photoelectric sensor after optical modulation;

the sample arm comprises a first collimating mirror and a low-pass reflector, the first collimating mirror is used for collimating light coming out of the coupler into collimated light rays, and the collimated light rays enter the fundus after being reflected by the low-pass reflector, and the sample arm is characterized in that:

and a flat glass which can rotate and can allow light to pass through is obliquely arranged between the first collimating mirror and the low-pass reflecting mirror and is close to the first collimating mirror.

2. The eye axis length measuring system according to claim 1, wherein: the optical imaging device is characterized by further comprising a Placido disc surface, an imaging mirror group and a cornea eye ground graph acquisition device, wherein a central hole is formed in the center of the Placido disc surface, a plurality of circles of light rings are arranged on the Placido disc surface, light emitted by the light rings of the Placido disc surface irradiates the eye ground, enters the low-pass reflector after being reflected, and light penetrating through the low-pass reflector enters the imaging mirror group and then enters the cornea eye ground graph acquisition device.

3. The eye axis length measuring system according to claim 2, wherein: the first large objective lens of the imaging lens group is positioned in a central hole of the Placido plate surface.

4. An eye axis length measuring system according to any one of claims 2-3, wherein: the cornea fundus graph acquisition device is a CCD.

5. The eye axis length measuring system according to claim 1, wherein: the reference arm comprises a second collimating mirror, two pyramid prisms and a reflector, light rays coming out of the coupler are collimated into collimated light rays through the second collimating mirror and then reach the reflector after passing through the two pyramid prisms, and the light rays reflected by the reflector return to the coupler in the original path.

6. The eye axis length measuring system according to claim 1, wherein: the inclination angle of the plate glass is 0.1-5 degrees.

Images