CN101278874A - A Transmissive Hartmann Measuring Instrument for Intraocular Lens Aberration - Google Patents

Abstract

The wave aberration Hartmann measurement instrument of transmission artificial lens mainly includes: light source, beam filtering system, internal focusing device, aperture division element, photodetector and computer, wherein the aperture division element and photodetector constitute the Hartmann wavefront Sensor; the light emitted by the light source, which is filtered by the beam filter system and collimated into parallel light, then exits, passes through the artificial lens to be tested, and the transmitted light wave carries the aberration information of the artificial lens into the internal focusing device, and passes through the internal The focusing device compensates the diopter of the intraocular lens. The compensated light wave is divided and sampled by the aperture division element and focused on the photodetector to form a spot array. The collected spot data is sent to the computer, and the total aberration of the artificial lens to be tested is obtained after processing. The invention has a simple and stable structure, and provides convenient, quick and reliable detection for ophthalmic clinical artificial lens implantation and processing and detection of individualized human eye aberration correction artificial lens.

Description

A Transmissive Hartmann Measuring Instrument for Intraocular Lens Aberration

technical field

The invention relates to a transmission-type artificial lens aberration Hartmann measuring instrument, which is a special device for clinical implantation of an artificial lens in ophthalmology, and is also a high-precision device for producing the artificial 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 (“Visual Performance after correcting the monochromatic and chromatic aberrations of the eye", Geun-Young Yoon 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 Basedon 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 transmission-type intraocular lens aberration Hartmann measuring instrument with good versatility, which can measure the aberration of intraocular lenses of any diopter, and is used for ophthalmology 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: a transmission-type intraocular lens aberration Hartmann measuring instrument, a light source, a beam filtering system, an internal focusing device, an aperture division element, a photodetector and a computer, wherein the aperture division element and the photodetector constitute Hartmann wavefront sensor; the light emitted by the light source, filtered by the beam filter system and collimated into parallel light, then exits, passes through the artificial lens to be tested, and the transmitted light wave carries the aberration information of the artificial lens into the internal adjustment Focusing device, through the internal focusing device to compensate the diopter of the artificial lens, that is, the defocus, the compensated light wave is divided and sampled by the aperture division element and focused on the photodetector to form a spot array, and the photodetector sends the collected spot data to the computer. The aberration of the incident light wave at this time is obtained through computer processing, and the total aberration of the artificial lens to be tested is obtained by synthesizing the focusing amount recorded by the internal focusing device.

The internal focusing device is composed of two beam matching telescopes composed of lenses or mirrors with different focal lengths.

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

The principle of the present invention is: the light emitted by the light source is collimated into parallel light, passes through the artificial lens to be tested, and the transmitted light wave carries the aberration information of the artificial lens into the internal focusing Hartmann wavefront sensor, and the artificial lens is controlled by the internal focusing device. The diopter of the crystal is compensated, and the amount of focusing is recorded. After the light wave passes through the internal focusing device, it is collimated into parallel light, which is segmented and sampled by the aperture division element and focused on the photodetector. The collected light spot data is sent to the computer for processing. The magnitude of the incident light wave aberration is obtained, and the total aberration of the artificial lens to be tested is obtained by synthesizing the magnitude of the focusing amount recorded by the internal focusing device.

The aperture division element may be a microlens array, or a microprism array or other aperture division elements with the same function. The photodetector can be either an imaging camera or a position sensor array.

Compared with the prior art, the present invention has the following advantages:

(1) The internal focusing device adopted in the present invention compensates the diopter of the intraocular lens, and measures the larger defocus and the remaining aberrations separately, reducing the aberration of the intraocular lens and measuring the requirements for the Hartmann dynamic range, the instrument It has good versatility and can measure the aberration of intraocular lenses of any diopter, providing convenient, fast and reliable detection for ophthalmology clinical intraocular lens transplantation and intraocular lens processing and testing.

(2) The present invention uses a Hartmann wavefront sensor with an internal focusing device to measure the aberration of the intraocular lens. Compared with the interferometer aberration detection method, it has low environmental requirements and is easy to realize a small aperture (about 5mm in the optical area of the intraocular lens). Complex high-order aberration detection has the advantages of simple structure and stability.

(3) The internal focusing device adopted in the present invention compensates the diopter of the intraocular lens, and the compensation amount is equal to the optical power of the intraocular lens, so the diopter of the lens can be obtained while obtaining the comprehensive aberration of the intraocular lens, and the versatility is good.

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 in the present invention that the aperture division element is a microlens array, and it includes a light source 1, a beam filtering system, an internal focusing device, an aperture division element 61, and a photodetector 62 and computer 7, wherein the aperture division element, i.e. microlens array 61 and photodetector 62 constitute a Hartmann wavefront sensor, the beam filtering system is composed of pinhole 2 and collimating mirror 3, and the inner focusing device 5 is composed of two different The focal length of the lenses or mirrors that make up the beam matches the telescope. The light emitted by the light source 1 is filtered by the pinhole 2, collimated by the collimating mirror 3 to be parallel light output, passes through the artificial lens 4 to be tested, and the transmitted light wave carries the aberration information of the artificial lens into the internal focusing Hartmann wavefront sensor , by moving the dotted line in Figure 1 to compensate for the diopter of the intraocular lens (that is, defocus), and record the amount of focus adjustment. After passing through the focusing device 5, the light wave is collimated into parallel light, divided and sampled by the microlens array 61 and focused on the photodetector 62 to form a spot array, and the collected spot data is sent to the computer 7, and the incident light wave at this time is obtained after processing The total aberration of the artificial lens to be tested is obtained by combining the focusing amount recorded by the internal focusing device.

As shown in FIG. 2 , the Hartmann wavefront sensor based on a microlens array is mainly composed of a microlens array 61 and a photodetection device 62 , wherein the photodetection device 62 is located on the focal plane of the microlens array 61 .

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 61, a spot array is formed on its 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 62 can be processed by a computer, using the centroid algorithm: calculate the position ( _xi , y _i ) of the light spot by the formula ①, and detect the wavefront error information of the full aperture:

$x_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{x}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}},$ ${\mathrm{the\; y}}_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{the\; y}}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{\mathrm{<figure-callout\; id="1"\; label="N\; I\; nm"\; filenames="A20071030451200081.png,A20071030451200083.png"\; state="\{\{state\}\}">N</figure-callout>}}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}{}_{}}$ 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 62, and l _nm is the signal received by the (n, m) pixel on the photodetector device 62, 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:

$g_{\mathrm{xi}}=\frac{\mathrm{\&Delta;x}}{\mathrm{\&lambda;f}}=\frac{x_i-x_o}{\mathrm{\&lambda;f}},$ $g_{\mathrm{yi}}=\frac{\mathrm{\&Delta;y}}{\mathrm{\&lambda;\; f}}=\frac{{\mathrm{the\; y}}_i-{\mathrm{the\; y}}_o}{\mathrm{\&lambda;\; <figure-callout\; id="2"\; label="f"\; filenames="A20071030451200081.png,A20071030451200083.png"\; state="\{\{state\}\}">f</figure-callout>}}$ 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, an internal focusing device, an aperture division element, that is, a microprism array 61', a Fourier lens or an imaging lens 63, a photodetector 62 and a computer 7, wherein the microprism array 61', a Fourier lens or The imaging lens 63 and the photodetector 62 constitute a Hartmann wavefront sensor, the beam filtering system consists of a pinhole 2 and a collimating mirror 3, and the inner focusing device 5 is a beam matching telescope composed of two lenses or reflectors with different focal lengths . The light emitted by the light source 1 is filtered by the pinhole 2, collimated by the collimating mirror 3 to be parallel light output, passes through the artificial lens 4 to be tested, and the transmitted light wave carries the aberration information of the artificial lens into the internal focusing Hartmann wavefront sensor , by moving the dotted line in Figure 1 to compensate for the diopter of the intraocular lens (that is, defocus), and record the amount of focus adjustment. After the light wave passes through the focusing device 5, it is collimated into parallel light. After passing through the microprism array 61', the Fourier lens or the imaging lens 63, it is segmented and sampled and focused on the photodetector 62 to form a spot array, and the spot data is collected and sent to the computer. 7. The aberration of the incident light wave at this time is obtained through processing, and the total aberration of the artificial lens to be tested is obtained by synthesizing the focusing amount recorded by the internal focusing device.

As shown in Figure 4, the Hartmann wavefront sensor based on the microprism array is mainly composed of a microprism array 61' with a zigzag phase grating structure, a Fourier lens or imaging lens 63 and a photodetector device 62, wherein the Fourier lens or imaging lens 63 is close to the microprism array 61 ′, and the photodetector device 62 is located on the focal plane of the Fourier lens or imaging lens 63 .

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 61', the beams of each sub-aperture respectively produce corresponding phase changes, and pass through the Fourier lens or imaging lens next to it. 63 imaging, the light intensity distribution is detected by the photodetector device 62 located on the focal plane of the Fourier lens or imaging lens 63, and the light intensity distribution contains the phase information generated by the two-dimensional zigzag phase grating array, and each sub-aperture produces The phase changes are different, so a spot array is formed on the focal plane of the Fourier lens (or imaging lens), 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 zigzag phase grating in its sub-aperture, and this phase change will be reflected in the spot position shift of the Fourier lens or the focal plane of the imaging lens superior.

The light spot signal received by the photodetector device 62 can be processed by a computer, using the centroid algorithm: calculate the position ( _xi , y _i ) of the light spot by the formula ①, and detect the wavefront error information of the full aperture:

$x_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{x}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}},$ ${\mathrm{the\; y}}_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{the\; y}}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{<figure-callout\; id="2"\; label="nm"\; filenames="A20071030451200081.png,A20071030451200083.png"\; state="\{\{state\}\}">nm</figure-callout>}}}$ ②

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 62, and l _nm is the signal received by the (n, m) pixel on the photodetector device 62, 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:

$g_{\mathrm{xi}}=\frac{\mathrm{\&Delta;x}}{\mathrm{\&lambda;f}}=\frac{x_i-x_o}{\mathrm{\&lambda;f}},$ $g_{\mathrm{yi}}=\frac{\mathrm{\&Delta;y}}{\mathrm{\&lambda;f}}=\frac{{\mathrm{the\; y}}_i-{\mathrm{the\; y}}_o}{\mathrm{\&lambda;\; <figure-callout\; id="2"\; label="f"\; filenames="A20071030451200081.png,A20071030451200083.png"\; state="\{\{state\}\}">f</figure-callout>}}$ 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 (6)

1, transmission-type artificial intraocular lenses wave aberration Hartmann measuring instrument, it is characterized in that mainly comprising: light source, light beam filtering system, interior focusing device, aperture segmentation element, photodetector and computer, wherein aperture segmentation element, photodetector constitute Hartmann wave front sensor; The light that sends by light source, the light that sends by light source outgoing after the filtering of light beam filtering system and collimation are directional light, pass artificial intraocular lenses to be measured, transmitted light wave is carried artificial intraocular lenses's aberration information and is entered the interior focusing device, is that out of focus compensates by the interior focusing device to artificial intraocular lenses's diopter, light wave after the compensation is sampled by the aperture segmentation element divisions and is focused on and forms spot array on the photodetector, photodetector will be gathered the hot spot data and send into computer, machine is handled the aberration size that obtains incident light wave this moment as calculated, and the focusing amount size of comprehensive interior focusing device recording obtains the total aberration of artificial intraocular lenses to be measured.

2, transmission type artificial crystal optical aberration hartmann measuring apparatus according to claim 1 is characterized in that: described interior focusing device is made of the Beam matching telescope that the lens or the reflecting mirror of two different focal constitutes.

3, transmission type artificial crystal optical aberration hartmann measuring apparatus according to claim 1 is characterized in that: described aperture segmentation element is a microlens array, or microprism array; When the aperture segmentation element was microlens array, photoelectric detector was positioned on the microlens array focal plane; When being microprism array, also be added with fourier transform lens or imaging len in the microprism array back, fourier transform lens or imaging len are near microprism array, and photoelectric detector is positioned on the focal plane of fourier transform lens or imaging len.

4, transmission type artificial crystal optical aberration hartmann measuring apparatus according to claim 1 is characterized in that: described photodetector is the imaging camera, or the position sensor array.

5, transmission type artificial crystal optical aberration hartmann measuring apparatus according to claim 1 is characterized in that: described light beam filtering system is made of pin hole and collimating mirror, and light beam is parallel light emergence through pin hole filtering by the collimating mirror collimation.

6, transmission type artificial crystal optical aberration hartmann measuring apparatus according to claim 1 is characterized in that: described light source is laser instrument or semiconductor laser or superradiance semiconductor device.

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