CN100589780C - A reflective artificial lens aberration Hartmann measuring instrument - Google Patents

Abstract

Reflective intraocular lens aberration Hartmann measuring instrument mainly includes: light source, beam matching system, standard spherical mirror, aperture division element, photodetector and computer, among which the aperture division element and photodetector constitute the Hartmann wavefront sensor ; The light emitted by the light source is collimated as parallel light, and the parallel light passes through the artificial crystal to be tested through the reflector and the beam splitter in turn, and the transmitted light wave reaches the standard spherical reflector, and the standard spherical reflector is adjusted axially to make the test The back focus of the artificial lens coincides with the center of the standard spherical mirror, and the reflected light wave returns along the original optical path and passes through the artificial lens to be tested again. After passing through the beam splitter and the beam matching system in turn, it is divided and sampled by the aperture division element and focused to the photoelectric detector. A light spot array is formed on the device, and the collected light spot data is sent to the computer, and the aberration of the artificial lens to be tested is obtained after processing. The invention has a simple and stable structure, and provides a convenient, fast and reliable detection tool for the implantation of ophthalmic clinical artificial lens and the processing and detection of individualized human eye aberration correction artificial lens.

Description

A reflective artificial lens aberration Hartmann measuring instrument

technical field

The invention relates to a reflective Hartmann measuring instrument for intraocular lens aberration, which is a special equipment for clinical ophthalmology implantation of intraocular lens, and is also a high-precision equipment for producing intraocular lens.

Background technique

At present, intraocular lenses have been widely used in the optical correction of high refractive errors and cataract surgery, but most of them can only correct low-order aberrations of the human eye such as defocus and astigmatism. Research shows that the human eye optical system not only has low-order aberrations, but also high-order aberrations such as coma, spherical aberration, etc. Correcting the low-order and high-order aberrations of the human eye at the same time can achieve better visual quality improvement (“VisualPerformance after correcting the monochromatic and chromatic aberrations of the eye", Geun-YoungYoon and David R.Williams, J.Opt.Soc.Am.A/Vol.19, No.2/February). Therefore, intraocular lenses that can only correct low-order aberrations of the human eye can no longer meet people's needs for refractive correction of the human eye, and intraocular lenses that can correct high-order aberrations of the human eye have become a new research hotspot and a future development trend. The basis for realizing this goal is the production of high-order aberration-correcting intraocular lenses of the human eye, and the detection of intraocular lenses is the basis of production.

Since the high-order aberration-correcting intraocular lens of the human eye not only corrects the low-order aberration of the human eye, but also corrects the high-order aberration of the human eye, the pure power detection cannot meet the detection requirements for the high-order aberration-correcting intraocular lens. It is necessary to measure the various order aberrations (low order and high order) of IOL comprehensively and objectively. At present, the high-order aberration-correcting intraocular lens of the human eye is still a novel type of intraocular lens, and the supporting technology is still under active research. The present invention proposes to use the Hartmann wavefront detection Low-order aberrations of intraocular lenses can also be used to measure high-order aberrations of intraocular lenses.

The Hartmann wavefront sensor is a simple and stable wavefront sensor, which divides and samples the incident light beam and focuses it on the photodetector, and obtains the wavefront phase distribution of the incident light through data processing. At present, Hartmann wavefront sensors are mainly based on microlens arrays ("Application of Hartmann wavefront sensors", Jiang Wenhan, Xian Hao, Yang Zeping, Journal of Quantum Electronics, Volume 15, Issue 2, Pages 228-235, 1998 Year) and two forms based on microprism array (“Hartmann-Shack Wavefront Sensor Based on a Micro-Grating Array”, Haiying Wang, Haifeng Duan, Changtao Wang, Yudong Zhang, SPIE, Vol.6018, 2005). Hartmann wavefront detection technology has been widely used in many fields such as human eye aberration measurement, beam quality diagnosis, and optical component inspection. However, the application of the Hartmann wavefront sensor to the measurement of the aberration of the artificial lens is still blank, and the present invention is proposed for this situation.

Contents of the invention

The problem solved by the technology provided by the present invention is: to overcome the deficiencies of the prior art, to provide a reflective intraocular lens aberration Hartmann measuring instrument with good versatility, which can measure the aberration of intraocular lenses of any diopter Provide convenient, fast and reliable detection for clinical intraocular lens implantation and processing and detection of intraocular lens.

The technical solution of the present invention is: reflective intraocular lens aberration Hartmann measuring instrument, mainly including: light source, beam filtering system, beam matching system, standard spherical mirror, aperture division element, photodetector and computer, wherein the aperture Segmentation elements and photodetectors constitute the Hartmann wavefront sensor; the light emitted by the light source is filtered and collimated by the beam filtering system and then emitted as parallel light. The transmitted light wave reaches the standard spherical reflector, and the standard spherical reflector is adjusted axially so that the back focus of the IOL to be tested coincides with the spherical center of the standard spherical reflector, and the reflected light wave returns along the original optical path and passes through the IOL to be tested again. After the beam splitter and the beam matching system, it is divided and sampled by the aperture division element and focused on the photodetector to form a spot array. The photodetector sends the collected spot data to the computer, and the aberration of the artificial lens to be tested is obtained by computer processing.

The standard spherical reflector can be a standard concave spherical reflector, or a standard convex spherical reflector.

The aperture division element is a microlens array, or a microprism array; when the aperture division element is a microlens array, the photodetection device is located on the focal plane of the microlens array; A Fourier lens or an imaging lens is added, the Fourier lens or the imaging lens is close to the microprism array, and the photoelectric detection device is located on the focal plane of the Fourier lens or the imaging lens.

The beam filtering system is composed of a pinhole and a collimating mirror. The beam is filtered by the pinhole and collimated by the collimating mirror to be parallel light to exit.

The photodetector can be either an imaging camera or a position sensor array.

The advantage of the present invention compared with prior art is:

(1) The present invention adopts the Hartmann wavefront sensor to measure the artificial crystal, and the detection beam passes through the artificial crystal to be measured twice, and by moving the mirror or fixing the mirror back and forth along the optical axis direction, the remaining part can be moved back and forth along the optical axis direction. It is convenient to realize the compensation of the diopter of the intraocular lens, measure the larger defocus and other aberrations separately, and reduce the requirement of the Hartmann dynamic range for the measurement of the aberration of the intraocular lens. The aberration measurement of the lens provides convenient, fast and reliable detection for ophthalmology clinical intraocular lens implantation and intraocular lens processing and testing.

(2) The present invention adopts moving the reflector back and forth along the optical axis direction or other parts to compensate the diopter of the intraocular lens, and the compensation amount is equal to the focal power of the intraocular lens, so the crystal diopter can be obtained while obtaining the comprehensive aberration of the intraocular lens Small size, good versatility.

(3) The present invention reconstructs the wavefront aberration by the restoration algorithm by measuring the position offset of the Hartmann sensor spot. Compared with the interferometer aberration detection method, the present invention has low requirements on the environment and is easy to realize small-caliber (intraocular lens) The optical zone is about 5mm) complex high-order aberration detection, with the advantages of simple structure and stability.

Description of drawings

Fig. 1 is the principle diagram of the artificial lens aberration measurement based on the microlens Hartmann of the present invention;

Fig. 2 is the Hartmann wavefront sensor structure and working principle schematic diagram based on microlens array among the present invention;

Fig. 3 is the schematic diagram of the artificial lens aberration measurement based on the microprism Hartmann of the present invention;

Fig. 4 is a schematic diagram of the structure and working principle of the Hartmann wavefront sensor based on the microprism array in the present invention.

Detailed ways

As shown in Figure 1, it is a schematic diagram of the intraocular lens aberration measurement principle diagram of the microlens array for the aperture division element in the present invention, and it comprises light source 1, beam filter system, beam matching system 8, standard spherical reflector 5, aperture division element , that is, the microlens array 91, the photodetector 92 and the computer 10, wherein the aperture division element 91 and the photodetector 92 form a Hartmann wavefront sensor, the beam filtering system consists of a pinhole 2 and a collimating mirror 3, and the beam matching system 8 A beam-matched telescope consisting of two lenses or mirrors of different focal lengths. The light emitted by the light source 1 is filtered by the pinhole 2, collimated by the collimator 3 to be parallel light exiting, passes through the artificial lens 6 to be tested through the reflector 4 and the beam splitter 7, and the transmitted light wave reaches the standard spherical reflector 5, Adjust the standard spherical reflector 5 axially so that the back focus of the IOL to be tested coincides with the spherical center of the standard spherical reflector, and the reflected light wave returns along the original optical path and passes through the IOL to be tested 6 again, passing through the beam splitter 7 and the beam matching system 8 Afterwards, it is segmented and sampled by the microlens array 91 and focused onto the photodetector 92 to form a spot array, and the photodetector 92 sends the collected spot data to the computer 10, and the aberration of the IOL to be tested is obtained through the computer 10 processing.

As shown in FIG. 2 , the Hartmann wavefront sensor based on the microlens array is mainly composed of a microlens array 91 and a photodetection device 92 , wherein the photodetection device 92 is located on the focal plane of the microlens array 91 .

The working principle of the Hartmann wavefront sensor based on the microlens array is as follows: After the incident light beam passes through the microlens array 91, a spot array is formed on the focal plane, and the entire beam aperture is evenly divided. Save the spot array generated by standard plane wave incidence as calibration data. When a wavefront with a certain aberration is incident, the local wavefront tilt on each microlens causes the position of the spot on the focal plane of the microlens array to shift.

The light spot signal received by the photodetector device 92 can be processed by the computer 10, using the centroid algorithm: calculate the position (xi _, y _i ) of the light spot by the formula ①, and detect the wave surface error information of the full aperture:

$x_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{x}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}},$ ${\mathrm{the\; y}}_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{the\; y}}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{\mathrm{<figure-callout\; id="1"\; label="N\; I\; nm"\; filenames="C2007103045130008H1.png,C2007103045130008H3.png"\; state="\{\{state\}\}">N</figure-callout>}}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}{}_{}}$ ①

In the formula, m=1～M, n=1～N is that the sub-aperture is mapped to the corresponding pixel area on the photodetector device 92, and l _nm is the signal received by the (n, m) pixel on the photodetector device 92, x _nm , y _nm are the x coordinate and y coordinate of the (n, m)th pixel respectively.

Then calculate the wavefront slope g _xi and g _yi of the incident wavefront according to formula ②:

$g_{\mathrm{xi}}=\frac{\mathrm{\&Delta;x}}{\mathrm{\&lambda;\; f}}=\frac{x_i-x_o}{\mathrm{\&lambda;\; f}},$ $g_{\mathrm{yi}}=\frac{\mathrm{\&Delta;y}}{\mathrm{\&lambda;f}}=\frac{{\mathrm{the\; y}}_i-{\mathrm{the\; y}}_o}{\mathrm{\&lambda;<figure-callout\; id="2"\; label="f"\; filenames="C2007103045130008H1.png,C2007103045130008H3.png"\; state="\{\{state\}\}">f</figure-callout>}}$ ②

In the formula, (x ₀ , y ₀ ) is the reference position of the center of the spot obtained by calibrating the Hartmann sensor with a standard plane wave; when the Hartmann sensor detects wavefront distortion, the center of the spot is shifted to ( _xi , y _i ), completing the Hartmann sensor Signal detection by a Terman wavefront sensor.

As shown in FIG. 3 , it is a schematic diagram of an intraocular lens aberration measurement in which the aperture division element is a microprism array in the present invention. It includes a light source 1, a beam filtering system, a beam matching system 8, a standard spherical mirror 5, an aperture division element, that is, a microprism array 91', a Fourier lens or an imaging lens 93, a photodetector 92 and a computer 10, wherein the aperture division element 91', Fourier lens or imaging lens 93 and photodetector 92 form the Hartmann wavefront sensor, the beam filtering system is made up of pinhole 2 and collimating mirror 3, the beam matching system 8 is made up of two lenses or mirrors with different focal lengths The resulting beam matches the telescope. The light emitted by the light source 1 is filtered by the pinhole 2, collimated by the collimator 3 to be parallel light exiting, passes through the artificial lens 6 to be tested through the reflector 4 and the beam splitter 7, and the transmitted light wave reaches the standard spherical reflector 5, Adjust the standard spherical reflector 5 axially so that the back focus of the IOL to be tested coincides with the spherical center of the standard spherical reflector, and the reflected light wave returns along the original optical path and passes through the IOL to be tested 6 again, passing through the beam splitter 7 and the beam matching system 8 Finally, the microprism array 91 ′, Fourier lens or imaging lens 93 are segmented and sampled and focused on the photodetector 92 to form a spot array, and the collected spot data is sent to the computer 10, and the aberration of the artificial lens to be tested is obtained after processing.

As shown in Figure 4, the Hartmann wavefront sensor based on the microprism array is mainly composed of a microprism array 91' with a sawtooth phase grating structure, a Fourier lens 93 and a photodetector device 92, wherein the Fourier lens 93 is close to the microprism array 91 ′, the photodetector device 92 is located on the focal plane of the Fourier lens 93 .

The working principle of the Hartmann wavefront sensor based on the microprism array is as follows: After the incident beam passes through the microprism array 91', the beams of each sub-aperture respectively produce corresponding phase changes, and pass through the Fourier lens or imaging lens next to it. 93 imaging, the light intensity distribution is detected by the photodetector device 92 located on the focal plane of the Fourier lens or imaging lens 93, and the light intensity distribution contains the phase information generated by the two-dimensional sawtooth phase grating array, and the generated by each sub-aperture The phase changes are different, so a spot array is formed on the focal plane of the Fourier lens or the imaging lens 93, and the entire beam aperture is evenly divided. The spot array generated by standard plane wave incidence will be saved as calibration data. When a wavefront with a certain aberration is incident, each local inclined plane wave produces a new additional phase to the two-dimensional sawtooth phase grating in its sub-aperture, and this phase change will be reflected in the spot position deviation of the Fourier lens or the focal plane of the imaging lens 93 move on.

The light spot signal received by the photodetector device 92 can be processed by the computer 10 in the same way as the aforementioned Hartmann wavefront sensor based on the microlens array. Using the centroid algorithm: Calculate the position ( _xi , y _i ) of the spot by the formula ①, and detect the wavefront error information of the full aperture:

$x_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{x}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}},$ ${\mathrm{the\; y}}_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{the\; y}}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{\mathrm{<figure-callout\; id="1"\; label="N\; I\; nm"\; filenames="C2007103045130008H1.png,C2007103045130008H3.png"\; state="\{\{state\}\}">N</figure-callout>}}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}{}_{}}$ ①

In the formula, m=1～M, n=1～N is that the sub-aperture is mapped to the corresponding pixel area on the photodetector device 92, and l _nm is the signal received by the (n, m) pixel on the photodetector device 92, x _nm , y _nm are the x coordinate and y coordinate of the (n, m)th pixel respectively.

Then calculate the wavefront slope g _xi and g _yi of the incident wavefront according to formula ②:

$g_{\mathrm{xi}}=\frac{\mathrm{\&Delta;x}}{\mathrm{\&lambda;f}}=\frac{x_i-x_o}{\mathrm{\&lambda;\; f}},$ $g_{\mathrm{yi}}=\frac{\mathrm{\&Delta;y}}{\mathrm{\&lambda;f}}=\frac{{\mathrm{the\; y}}_i-{\mathrm{the\; y}}_o}{\mathrm{\&lambda;<figure-callout\; id="2"\; label="f"\; filenames="C2007103045130008H1.png,C2007103045130008H3.png"\; state="\{\{state\}\}">f</figure-callout>}}$ ②

In the formula, (x ₀ , y ₀ ) is the reference position of the center of the spot obtained by calibrating the Hartmann sensor with a standard plane wave; when the Hartmann sensor detects wavefront distortion, the center of the spot is shifted to ( _xi , y _i ), completing the Hartmann sensor Signal detection by a Terman wavefront sensor.

Claims (7)

1. The reflective artificial lens aberration Hartmann measuring instrument is characterized in that it mainly includes: a light source, a beam filtering system, a beam matching system, a standard spherical mirror, an aperture division element, a photodetector and a computer, wherein the aperture division element, The photodetector constitutes a Hartmann wavefront sensor; the light emitted by the light source is filtered and collimated by the beam filtering system and then emitted as parallel light. Standard spherical reflector, adjust the standard spherical reflector axially, so that the back focus of the artificial lens to be tested coincides with the spherical center of the standard spherical reflector, and the reflected light wave returns along the original optical path and passes through the artificial lens to be tested again, and passes through the beam splitter and After the beam matching system, it is segmented and sampled by the aperture division element and focused on the photodetector to form a spot array. The photodetector sends the collected spot data to the computer, and the aberration of the artificial lens to be tested is obtained by computer processing. 2. The reflective IOL aberration Hartmann measuring instrument according to claim 1, characterized in that: said standard spherical reflector is a standard concave spherical reflector, or a standard convex spherical reflector. 3. The reflective intraocular lens aberration Hartmann measuring instrument according to claim 1, characterized in that: the aperture division element is a microlens array or a microprism array; when the aperture division element is a microlens array , the photodetection device is located on the focal plane of the microlens array; when it is a microprism array, a Fourier lens or an imaging lens is added behind the microprism array, and the Fourier lens or imaging lens is close to the microprism array, and the photodetection device is located in the Fourier lens Or the focal plane of the imaging lens. 4. The reflective IOL aberration Hartmann measuring instrument according to claim 1, characterized in that: said photodetector is an imaging camera, or an array of position sensors. 5. The reflective intraocular lens aberration Hartmann measuring instrument according to claim 1, characterized in that: the beam filtering system is composed of a pinhole and a collimating mirror, the beam is filtered by the pinhole, and the collimating mirror Collimated for parallel light exit. 6. The reflective IOL aberration Hartmann measuring instrument according to claim 1, characterized in that: said beam matching system is composed of two lenses or mirrors with different focal lengths. 7. The reflective artificial lens aberration Hartmann measuring instrument according to claim 1, characterized in that: said light source is a laser or a superradiative semiconductor device.

Images