CN102283633A - An Adaptive Optics Micro Perimeter - Google Patents

Abstract

An adaptive optical micro-perimeter, an infrared beacon emits infrared light to the pupil of a detected person, a Hartmann wavefront sensor measures the wavefront aberration of the human eye carried by reflected light of the eyeground, and a computer calculates control voltage according to the measured aberration and drives a wavefront corrector to correct the aberration of the human eye. After the aberration correction is completed, a fixed optotype for fixing the line of sight of the subject and a light-stimulating optotype for providing light stimulation to the fundus of the subject are displayed at a plurality of predetermined positions on the stimulating optotype display means. The pupil camera uses infrared light emitted by the infrared light source in front of the eye to shoot the pupil image of the human eye of the detected person and calculate the pupil diameter, and the computer controls and changes the light stimulation sighting target according to the change of the pupil diameter of the detected person and measures the visual field of the detected person. The invention has high reliability, reduces the stimulation redundancy caused by the aberration of the human eyes in the visual field inspection, is beneficial to finding early micro-visual field defects and provides a powerful tool for evaluating the micro-visual field defects of the human eyes and diagnosing related diseases.

Description

An Adaptive Optics Micro Perimeter

technical field

The invention relates to an adaptive optical microperimeter, which is an optical instrument for precise and objective measurement of early microperimetry defects of human eyes without relying on the subject's subjective judgment.

Background technique

Perimeter, as a widely used main visual function test method, provides important information for the diagnosis and monitoring of glaucoma and some other visual and optic nerve diseases, and creates conditions for successful treatment. The traditional perimetry checks the visual field of the subject by displaying the optical stimulus target (eye_target) at a specific position in front of the subject's eyes, asking the subject whether he sees the target, and changing the optical stimulus target (change amount) according to the answer. It can be the brightness, size, shape, etc. of the visual target), and continue to ask the subject until the optical stimulation target reaches the visual threshold of the subject (threshold). The subject's visual threshold reflects the minimum amount of stimulation that can cause the subject's visual response, the most commonly used is the brightness of the stimulus, and the measured visual threshold is the light difference sensitivity threshold. There are two major problems with conventional perimetry.

First, traditional perimetry is difficult to detect early subtle visual field defects. Taking glaucoma as an example, by the time visual field defects can be diagnosed using standard automated perimetry, 25% to 30% of ganglion cells have died, and there may be more ganglion cells that have lost function or reduced sensitivity, and the disease has already very serious.

The main reasons why early subtle visual field defects are difficult to diagnose clinically with traditional perimetry are "visual redundancy" and "stimulus redundancy". Visual redundancy refers to the fact that the response of the human eye to the stimulus visual target is the result of the joint action of multiple neurons or functional cells. Stimulus redundancy means that the stimulus visual target passes through the internal optical path of the perimeter and the refractive system of the human eye, covering a certain area in the fundus instead of stimulating single cells, so that the subject's response is the cone cells in the area covered by the stimulus and the cone cells directly with it. Or the comprehensive result of the joint response of all the functional cells that are indirectly connected. The imaging of the stimulus target in the fundus is inevitably affected by the aberration of the human eye. The size of the aberration of the human eye determines the quality of the stimulus spot projected to the fundus. The existence of the aberration of the human eye causes the deformation and expansion of the stimulus optotype in the fundus. Even if a small stimulus target is used, redundant stimulation will be formed. If only a part of the functional cells in the stimulus range of the visual target lose function and the rest of the cells function normally, the subject can still make a judgment of feeling the stimulus by means of the response of the normal cells to the stimulus visual target. Therefore, when the visual field defect manifests as an early subtle defect, due to the existence of visual redundancy and stimulus redundancy, this subtle defect is difficult to diagnose with traditional visual field examination methods.

Chinese Invention Patent Publication No. CN101336823B discloses an adaptive optics micro-view defect evaluation system. In this system, infrared beacon light is used to form a beacon on the fundus of the subject, and the reflected beam reflected from the pupil carries the aberration of the human eye. After calculating and correcting the aberration of the human eye by using adaptive optics technology, Visual field examination was then performed using a micro-stimulus visual standard. This method greatly reduces the "stimulus redundancy" in visual field evaluation, thus effectively evaluating the early subtle visual field defects of the human eye.

Secondly, the traditional visual field test is a kind of subjective visual function test, and the test results are affected by various psychophysical factors, such as the subject's cognitive ability and attention, etc., and the repeatability is poor, which brings certain difficulties to the interpretation of visual field results . In addition, the change of the visual target during the test is based on the subject’s last response to the same location stimulus. If the subject makes too many misjudgments during the test, the error of the result is often too large. It will be long and the subject will be overburdened. The perimetry disclosed in the Chinese Invention Patent Publication No. CN101336823B adopts the traditional perimetry method based on subjective responses, so the above-mentioned problems also exist.

Chinese Invention Patent Announcement No. CN101018501A discloses an objective perimetry that can quickly and accurately detect the visual field without relying on the subject's subjective answer. In this perimetry, the pupil diameter change of the subject is detected while providing light stimulation to the retina of the subject, that is, the miosis response of the pupil due to the light stimulation is detected. Since the sensitivity of light that causes pupillary light reflection is 7.7dB higher than that of ordinary perimetry, it will be more accurate and objective to judge the visual function of the subject according to the change of pupil diameter. However, the stimulus optotype of this perimetry still adopts the traditional optical path projection, without considering the impact of stimulus redundancy on the examination results, and it is difficult to effectively diagnose early subtle visual field defects.

In addition, according to the distribution of human visual photoreceptor cells, cone cells are mainly distributed in the macular area of the retina, and can be divided into green, yellow and red trichromatic cells according to their optimal stimulation spectrum. They are at 430nm, 555nm, and 630nm respectively; rod cells are mainly distributed in the peripheral area of the retina, and the optimal stimulation spectrum is at 508nm; photoreceptor ganglion cells are distributed throughout the retina, mainly feeling strong light stimulation, and the optimal stimulation spectrum is 480nm. Using monochromatic light with different wavelengths as light stimulation for visual field inspection can more accurately identify the type of diseased cells and further improve the accuracy of analysis.

Contents of the invention

The technical solution of the present invention is to overcome the deficiencies of the prior art and provide a perimetry that does not rely on the subject's subjective response, can greatly reduce stimulus redundancy, and can quickly, accurately and effectively perform objective perimetry.

Technical solution of the present invention: an adaptive optical microperimeter, including: infrared beacon, collimating mirror, first beam splitter, second beam splitter, human eye, beam matching telescope, wavefront corrector, beam matching Telescope, second reflector, third beam splitter, Hartmann wavefront sensor, computer, high-voltage amplifier, third reflector, optotype imaging optical system, stimulus optotype display device, first reflector, pupil imaging optical system and pupil cameras.

An infrared beacon for emitting infrared light to the subject's eyes. The position of the human eye can be adjusted by the head support. The beacon light is collimated by the collimator, enters the pupil of the examinee through the first beam splitter and the second beam splitter, and forms a beacon light source in the fundus. The beacon beam is reflected by the fundus and transmitted out of the pupil of the human eye, and the aberration it carries is the wavefront aberration of the human eye. The beacon beam passes through the second beam splitter, the beam matches the telescope, is reflected by the wavefront corrector, passes through the beam matching telescope, the second reflector and the third beam splitter enter the Hartmann wavefront sensor; the Hartmann wavefront sensor, Aperture segmentation is performed on the incident beam, and the beams in each sub-aperture are focused on the image plane of the CCD camera. The wavefront sensor calculates the spot offset of each sub-aperture according to the obtained image. The computer calculates the wavefront slope in each subaperture according to the spot offset of each subaperture, calculates the wavefront aberration of the human eye carried by the beam, and processes the wavefront corrector according to the measured wavefront aberration of the human eye through control software Control voltage; after the voltage control signal is amplified by a high-voltage amplifier, it drives each drive motor of the wavefront corrector to change the surface shape of the reflective mirror of the wavefront corrector, thereby correcting the wavefront aberration of the human eye; after the aberration correction is completed, the computer acts as a stimulus for viewing The target control device displays fixed optotypes for fixing the line of sight of the examinee and light stimulation optotypes for providing light stimulation to the fundus of the examinee at a plurality of predetermined positions on the stimulus optotype display device. Stimulate the visual target through the visual target imaging optical system, the third reflector, the third beam splitter, the second reflector, the second beam matching telescope, the wavefront corrector, the first beam matching telescope, and the second beam splitter. Visual field stimulation is performed on the subject's eyes; a pupil camera is used to monitor the pupil diameter change of the subject during the test. When the subject looks at the fixed optotype, when the stimulus optotype display device displays the optical stimulus optotype, the pupil camera uses infrared light in front of the eyes to capture the pupil image, and detects the subject's pupil Diameter change, measured in the subject's visual field.

The Hartmann wavefront sensor is a Hartmann wavefront sensor based on a microprism array; the wavefront corrector is a deformable mirror, or a liquid crystal wavefront corrector, or a micromechanical deformable mirror, or a dual pressure Electric ceramic deformable mirror; described stimulating visual mark display device is a display device such as a CRT display, or a commercial projector, or a color liquid crystal display, or a plasma that can adjust the background brightness of the screen and the described visual mark color, brightness and size Body display, or electroluminescent display, or organic light-emitting display; the pupil camera is an infrared digital video camera; the infrared beacon can be an infrared laser, or an infrared semiconductor laser, or an infrared super-radiation semiconductor device; The pupil imaging illumination light source can be an infrared light emitting diode, or an Array array infrared light source.

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

(1) The present invention uses adaptive optics technology to correct the dynamic aberration of the human eye in real time, which greatly reduces the stimulus redundancy caused by the aberration of the human eye, which is conducive to the discovery of early subtle visual field defects and improves the accuracy of detection;

(2) The detection result of the present invention is based on the pupil diameter change of the subject under light stimulation, independent of the subject's subjective response, and can more accurately and objectively evaluate the subject's visual field defect;

(3) In the present invention, the wavelength of the stimulating visual target light is variable, and the monochromatic light of a few wavelengths can be used to gate the visual path according to the different detection purposes, and to identify the types of diseased functional cells;

(4) The stimulus visual target control of the present invention is completed by computer software. The computer sends video signals to the display device for stimulating optotypes for display, and the size, quantity, position, brightness, and period of the stimulating optotypes can be precisely controlled by the computer. The visual field test stimulus visual target design is more flexible, so that it can effectively detect randomly distributed subtle visual field defects or central scotoma;

(5) The beacon light used in the present invention is infrared light invisible to the human eye, which can avoid the influence of the beacon light on the human eye's judgment of the optical stimulus during the detection process. Throughout the visual field inspection process, the adaptive optics system is in a closed-loop state, real-time monitoring and correction of human eye aberrations, greatly reducing the impact of stimulus redundancy, so that the visual field inspection process is not affected by stimulus redundancy;

(6) The stimulus visual target in the present invention is a light stimulus that flickers briefly in the form of pulses, and the light stimulus visual target at the same position and the same brightness blinks continuously at least twice. Repetitive short-term stimulation is beneficial to judge whether the change of pupil diameter is caused by light stimulation, and improve the reliability of the detection result.

Description of drawings

Figure 1 is a schematic diagram of the system structure of the adaptive optics microperimeter;

Figure 2a is a schematic diagram of the structure of a Hartmann wavefront sensor based on a microprism array; Figure 2b is a schematic diagram of the working principle of a Hartmann wavefront sensor based on a microprism array;

Figure 3a is a schematic diagram of the structure of a Hartmann wavefront sensor based on a microlens array; Figure 3b is a schematic diagram of the working principle of a Hartmann wavefront sensor based on a microlens array;

Fig. 4a is a schematic diagram of the distribution of the fixed optotype position and the preset position of the stimulating optotype; Fig. 4b is a schematic diagram of giving a single light stimulus to the subject;

Figure 5a is a schematic diagram of the pupil diameter change curve after the human eye is subjected to a single short-pulse light stimulation; Figure 5b is a schematic diagram of the pupil diameter change after the human eye is subjected to two consecutive short-pulse light stimulations;

In the figure: 1 is the infrared beacon, 2 is the collimating mirror, 3 is the first beam splitter, 4 is the second beam splitter, 5 is the human eye, 6 is the first beam matching telescope, 7 is the wavefront corrector, 8 is The second beam matching telescope, 9 is the second reflector, 10 is the third beam splitter, 11 is the Hartmann wavefront sensor, 12 is the computer, 13 is the high-voltage amplifier, 14 is the third reflector, 15 is the visual target imaging Optical system, 16 is a stimulus visual target display device, 17 is a first mirror, 18 is a pupil imaging optical system, 19 is a pupil camera.

Detailed ways

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a schematic diagram of the system structure of the adaptive optics microperimeter of this embodiment. Adaptive optics microperimetry includes: infrared beacon 1, collimating mirror 2, first beam splitter 3, second beam splitter 4, human eye 5, first beam matching telescope 6, wavefront corrector 7, second beam Matching telescope 8, second mirror 9, third beam splitter 10, Hartmann wavefront sensor 11, computer 12, high-voltage amplifier 13, third mirror 14, visual mark imaging optical system 15, stimulus visual mark display device 16 , a first mirror 17 , a pupil imaging optical system 18 and a pupil camera 19 . The infrared beacon 1 can be a laser, a semiconductor laser diode, and a superluminescent diode-SLD; the wavefront corrector 7 can be a deformable mirror, a liquid crystal wavefront corrector liquid crystal device, a micromechanical deformable mirror micro -machined deformable mirror and double piezoelectric ceramic deformable mirror bimorph mirror; Hartmann wavefront sensor 11 can be based on the Hartmann wavefront sensor of microprism array, or based on the Hartmann wavefront sensor of microlens array; Stimulus The visual mark display device 16 can be a CRT display, a commercial projector, a color liquid crystal display, a plasma display, an electroluminescent display and an organic light-emitting display; the pupil camera 19 is an infrared digital video camera; the pupil imaging illumination source It can be an infrared light emitting diode, or an Array array infrared light source. Elimination of stray light from the human cornea can be eliminated by off-axis illumination; or by polarized light source illumination, the reflected light of the fundus is depolarized, and the scattered light of the cornea is not depolarized, and is filtered out by detecting different polarization states through the analyzer Corneal stray light. Except for the human eye 5 and the computer 12, the entire system is encapsulated with a housing with an inner surface emissivity of 1.

The working process of the adaptive optics microperimetry in this embodiment is as follows: use the head support to adjust the human eye to a proper position. The infrared beacon light 1 is collimated by the collimating mirror 2, enters the pupil 5 of the examinee through the first beam splitter 3 and the second beam splitter 4, and forms a beacon light source in the fundus. The beacon beam is reflected by the fundus and transmitted out of the pupil of the human eye, and the aberration it carries is the wavefront aberration of the human eye. The beam of the infrared beacon 1 passes through the second beam splitter 4, the beam matches the telescope 6, is reflected by the wavefront corrector 7, passes through the beam matching telescope 8, the second reflector 9, and the third beam splitter 10 enter the Hartmann wavefront Sensor 11; the Hartmann wavefront sensor 11 divides the incident beam into apertures, focuses the beams in each sub-aperture onto the image plane of the CCD camera, and the wavefront sensor 11 calculates the spot offset of each sub-aperture according to the obtained image. The computer 12 calculates the wavefront slope in each subaperture according to the spot offset of each subaperture, and calculates the wavefront aberration of the human eye carried by the beam, and then according to the relationship matrix between the driver voltage on the wavefront corrector and the subaperture slope Calculate the control voltage of the wavefront corrector 7; the voltage control signal is amplified by the high-voltage amplifier 13 to drive each drive motor of the wavefront corrector 7, and change the shape of the mirror surface of the wavefront corrector 7, thereby correcting the wavefront aberration of the human eye. After the aberration correction is completed, the computer 12, as the control device of the stimulus optotype, displays fixed optotypes for fixing the line of sight of the examinee and providing light to the fundus of the examinee at a plurality of predetermined positions on the stimulus optotype display device 16. Stimulate the photostimulus optotype. The visual mark imaging optical system 15 is a convex lens, stimulates the visual target light to exit with parallel light after passing through the visual mark imaging optical system, then passes through the third reflector 14, the third beam splitter 10, the second reflector 9, and the second light beam matching The telescope 8, the wavefront corrector 7, the first beam matching telescope 6, and the second beam splitter 4 stimulate the visual field of the subject's eyes; the pupil camera 19 monitors the pupil diameter change of the subject during the test . When the subject looks at the fixed optotype, the stimulus optotype display device displays the photostimulus optotype, and at the same time, the light beam of the infrared beacon 1 is used to illuminate the eyes, and the pupil reflected light passes through the second beam splitter 4. After the first spectroscope 3 and the first reflecting mirror 17, the pupil imaging optical system 18 is focused on the target surface of the pupil camera 19 to obtain a pupil image, detect the pupil diameter change of the subject, and measure the pupil diameter change of the subject. examiner's field of view. Wherein, the pupil imaging optical system 18 is a convex lens. The beacon light used in the present invention is infrared light invisible to the human eye, which can avoid the influence of the beacon light on the human eye's judgment of the light stimulus visual mark during the detection process. Throughout the visual field inspection process, the adaptive optics system is in a closed-loop state, real-time monitoring and correction of human eye aberrations, greatly reducing the impact of stimulus redundancy, so that the visual field inspection process is not affected by stimulus redundancy.

The Hartmann wavefront sensor 11 may be a Hartmann wavefront sensor based on a microprism array, as shown in Fig. 2a. It consists of a microprism array 11-1, a Fourier lens 11-2 and a CCD 11-3 located at the focal plane of the lens. The microprism array 11-1 has a two-dimensional zigzag phase grating structure, and performs aperture division on the incident beam, and divides it into several sub-aperture beams. Each sub-hole light produces a phase change corresponding to the two-dimensional zigzag phase grating it passes through, passes through the Fourier lens 11-2, and reaches the CCD 11-3 on the focal plane of the Fourier lens 11-2, forming a spot array. The entire sub-aperture is evenly cut. Since the incident light beam carries image wavefront aberration, 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 is reflected in the light spot on the focal plane of Fourier lens 11-2 position offset. The offset of the center of the sub-aperture spot relative to the reference position of the center of the focal spot determined by a standard parallel cursor is proportional to the slope of the wavefront.

The computer 12 receives and processes the sub-aperture spot signals collected by the Hartmann wavefront sensor 11 . The center position (xi _, y _i ) of the sub-aperture spot is calculated using the centroid algorithm (formula ①) to calculate the position of the spot:

$x_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{x}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{nm}}},$ ${\mathrm{the\; y}}_i=\frac{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{the\; y}}_{\mathrm{nm}}{I}_{\mathrm{nm}}}{\underset{m=1}{\overset{m}{\mathrm{\&Sigma;}}}\underset{\mathrm{no}=1}{\overset{N}{\mathrm{\&Sigma;}}}{I}_{\mathrm{<figure-callout\; id="1"\; label="nm"\; filenames="HDA0000076752740000031.png"\; state="\{\{state\}\}">nm</figure-callout>}}}$ ①

Wherein, m=1～M, n=1～N is that the sub-aperture is mapped to the corresponding pixel area on the CCD 11-3 photosensitive target surface; M and N are respectively the horizontal and vertical directions of the sub-aperture mapped to the corresponding area on the photosensitive target surface Number of pixels, I _nm is the signal received by the (n, m) pixel on the CCD 11-3 photosensitive target surface, and x _nm , y _nm are the x coordinate and the y coordinate of the (n, m) pixel respectively.

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

$g_{\mathrm{xi}}=\frac{\mathrm{\&Delta;x}}{\mathrm{\&lambda;f}}=\frac{x_i-x_o}{\mathrm{\&lambda;f}},$ $g_{\mathrm{yi}}=\frac{\mathrm{\&Delta;y}}{\mathrm{\&lambda;f}}=\frac{{\mathrm{the\; y}}_i-{\mathrm{the\; y}}_o}{\mathrm{\&lambda;\; <figure-callout\; id="2"\; label="f"\; filenames="HDA0000076752740000011.png,HDA0000076752740000031.png"\; state="\{\{state\}\}">f</figure-callout>}}$ ②

In the formula, (x ₀ , y ₀ ) is the reference position of the spot center obtained by the standard parallel cursor calibration Hartmann sensor; when the Hartmann sensor detects wavefront distortion, the center of the spot is shifted to ( _xi , y _i ), and the The schematic diagram of the signal detection by the Hartmann wavefront sensor is shown in Figure 2b.

The Hartmann wavefront sensor 11 can also be a Hartmann wavefront sensor based on a microlens array, as shown in Figure 3a, it is made up of a microlens array 11-4 and a photodetector device 11-5, and its working principle is: incident After the beam passes through the microlens array 11-4, a spot array is formed on its focal plane, and the entire beam aperture is evenly divided; the spot array generated by standard plane wave incidence is saved 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 11-4 to shift. The schematic diagram of its working principle is shown in Figure 3b. The light spot signal received by the photodetection device 11-5 is processed by the computer 12, and the processing method is the same as that of the aforementioned Hartmann wavefront sensor based on the microprism array.

Through experiments, according to the effect on the slope of the sub-aperture when each driver on the wavefront corrector 7 applies a unit voltage, a slope response matrix R from the phase correction amount of the wavefront corrector 7 to the Hartmann sensor 11 is established. When each sub-aperture control voltage is within a suitable range, the phase correction amount of the wavefront corrector 7 is approximately linear with the driver voltage, and satisfies the superposition principle, and the sub-aperture slope is also linearly related to the driver voltage, and satisfies the superposition principle. Assuming that V is the control voltage matrix of the wavefront corrector, the average wavefront slope matrix in the sub-aperture of the Hartmann sensor is G, and the two satisfies:

G＝RV ③

The wavefront aberration slope G to be corrected is calculated by the Hartmann sensor 11, and the control voltage of the wavefront corrector 7 can be obtained by generalized inversion:

V＝R ⁺ G ④

After the control signal is amplified by the high-voltage amplifier 13, it drives the deformable mirror of the wavefront corrector 7 to realize the closed-loop control of wavefront correction. After several iterations, the residual wavefront error is corrected to a minimum, and the whole system obtains a stable correction effect. Stimulus redundancy is well controlled.

The computer 12 is used as a control device for stimulating optotypes, and displays fixed optotypes for fixing the line of sight of the examinee and optical stimulation optotypes for providing optical stimulation to the fundus of the examinee at a plurality of predetermined positions on the stimulus optotype display device 16 . The number and position of the optical stimulation targets can be changed according to different detection purposes. Fig. 4a shows a schematic diagram of the position distribution of a fixed optical target and a predetermined optical stimulation target. The computer 12 sets a reasonable background brightness and the initial intensity of the optical stimulus at each predetermined position according to the state of the subject (gender, age, medical history, etc.) according to the experience database, and randomly selects one of the predetermined positions to display the corresponding intensity of the light stimulus Visual mark, as shown in Figure 4b. Adjust the position of the subject so that the center of the pupil of the human eye 5 coincides with the optical axis of the system, and the subject keeps facing up to the fixed target and feels the intermittent light stimulation within the field of vision without subjective judgment. .

The activity of the pupil is regulated by the sympathetic nervous system and the parasympathetic nervous system respectively controlling the pupillary dilator muscle and the pupillary sphincter, and the dilation and contraction of the pupil is a kind of stress response. When light stimulation is provided to the subject's eyes at any position in the normal visual field area, the parasympathetic nervous system receives the stimulation information and controls the reflexive contraction of the pupillary sphincter, that is, the miosis response. After the light stimulus disappeared, the pupil dilated, as shown in Figure 5a. This stress response is a brainstem reflex, which is usually impossible for the subject to control voluntarily. The pupil camera 19 captures the pupil image of the human eye through the pupil imaging optical system, the first mirror, the first beam splitter, and the second beam splitter. Imaging lighting adopts the infrared light source in front of the eyes, and the infrared light source can be an infrared light-emitting diode or an Array array infrared light source. The computer 12 extracts pupil information from the obtained human eye pupil image according to the feature extraction method and calculates the pupil diameter, and then calculates the miosis ratio according to the change of the pupil diameter as an index to judge the objective reaction of the subject to the so-called stimulus.

The present invention uses a threshold detection method to analyze the visual function of the subject, which is similar to a static perimetry. The threshold standard is the minimum light intensity at which the pupil constriction exceeds 3 mm. The change of the light intensity of the stimulus point is changed in steps according to the logarithmic unit. With a certain sample size, the pupil constriction thresholds of normal human eyes at various positions are taken as the benchmark reference thresholds. When testing the subject, start from the reference threshold intensity, change the stimulus intensity, and repeat the detection of the predetermined position until the given light stimulus intensity just causes the pupil to constrict. Visual function of the test subject.

In addition, miotic constriction decreases with age, and in some subjects the miotic constriction in response to a single short photo-stimulus is so small that it is difficult to detect. Therefore, when formulating benchmark reference thresholds, it is necessary to classify them according to different age groups. In addition, in a stable situation without light stimulation, the size of the pupil diameter will also fluctuate. Therefore, it is difficult to determine whether the pupil diameter is caused by light stimulation only by a single light stimulation. The method of using the same light stimulus multiple times in a short time is helpful to judge the miotic response under the light stimulus. Fig. 5b shows the change of the pupil diameter of the subject under the condition of two consecutive light stimulations. In the example, the pupil diameter curve of a normal human eye undergoes peak-to-valley changes with the light stimulation. In actual operation, the number of stimuli used for a single point can be set according to the specific situation, so as to judge the response of the subject more effectively. Since pupil constriction is affected by psychological factors, the testing environment should be as quiet as possible, and the subjects should be fully relaxed to improve the accuracy of testing.

The color of the optical stimulus visual target can be changed according to the detection requirements. This is because the sensitivity of the retina varies with the stimulus wavelength, and the optimal stimulus spectrum for different functional cells is different. Using monochromatic light with different wavelengths as light stimulation for visual field inspection can effectively perform visual pathway gating, more accurately screen the types of diseased cells, and effectively identify detailed functional defects.

The above-mentioned embodiments are only used to illustrate the technical route of the present invention and not to limit, and different embodiments of the present invention can be widely constructed without departing from the spirit and scope thereof. It should be understood that the present invention is not limited to its specific examples, but should be included within the scope of the claims.

Claims (10)

1. the little perimeter of adaptive optics is characterized in that comprising: infrared beacon (1), collimating mirror (2), first spectroscope (3), second spectroscope (4), human eye (5), the first Beam matching telescope (6), wave-front corrector (7), the second Beam matching telescope (8), second reflecting mirror (9), the 3rd spectroscope (10), Hartmann wave front sensor (11), computer (12), high-voltage amplifier (13), the 3rd reflecting mirror (14), sighting target imaging optical system (15), stimulate Optotype presenting apparatus (16), first reflecting mirror (17), pupil imaging optical system (18) and pupil camera (19);

The infrared beacon light that infrared beacon (1) sends is collimated by collimating mirror (2), behind first spectroscope (3), second spectroscope (4), enter human eye (5) pupil successively, optical fundus the people forms a luminous point, it is beacon, this beacon beam is through remarkable fundus reflex, transmit the human eye pupil, the aberration that carries is a human eyes wave-front optical aberration; The beacon beam that this aberration that carries is a human eyes wave-front optical aberration sees through second spectroscope (4) and Beam matching telescope (6) back is reflected by wave-front corrector (7), enters Hartmann wave front sensor (11) by the second Beam matching telescope (8), second reflecting mirror (9) and the 3rd spectroscope (10) again; Hartmann wave front sensor (11) carries out aperture segmentation to incident beam, and the light beam in each sub-aperture is focused on the image planes of CCD camera, according to each sub-aperture light speckle side-play amount of gained image calculation, sends in the computer (12); Computer (12) calculates wavefront slope in each sub-aperture according to each sub-aperture hot spot side-play amount, calculates the entrained human eyes wave-front optical aberration of light beam, and obtains wave-front corrector (7) control voltage according to the human eyes wave-front optical aberration that records through the control software processes; The control voltage signal changes the face type of wave-front corrector (7) mirror surface through each drive motors of high-voltage amplifier (13) amplification rear drive wave-front corrector (7), thereby proofreaies and correct human eyes wave-front optical aberration; After aberration correction is finished, computer (12) is as the control device that stimulates sighting target, stimulating a plurality of precalculated positions on the Optotype presenting apparatus (16) to show fixation target that is used for fixing person under inspection's sight line and the photostimulation sighting target that is used for providing photostimulation to the person under inspection optical fundus, stimulate sighting target through sighting target imaging optical system (15), the 3rd reflecting mirror (14), the 3rd spectroscope (10), second reflecting mirror (9), the second Beam matching telescope (8), wave-front corrector (7), the first Beam matching telescope (6), second spectroscope (4), described person under inspection's eyes are carried out the visual field to stimulate; The pupil diameter that pupil camera (19) is used to monitor person under inspection described in the test process changes, when seeing described person under inspection under the condition of described fixation target, when described stimulation Optotype presenting apparatus (16) display light stimulates sighting target, pupil camera (19) utilizes the pupil image of infrared illumination picked-up at the moment, the pupil diameter that detects described person under inspection changes, and measures described person under inspection's the visual field.

2. the little perimeter of adaptive optics according to claim 1 is characterized in that: described infrared beacon (1) is infrared laser, infrared semiconductor laser or infrared excess radiation-emitting semi-conductor device.

3. the little perimeter of adaptive optics according to claim 1 is characterized in that: described wave-front corrector (7) is deformation reflection mirror, liquid crystal wave-front corrector, micromechanics deformation of thin membrane mirror or double piezoelectric ceramic distorting lens.

4. the little perimeter of adaptive optics according to claim 1 is characterized in that: described Hartmann wave front sensor (11) is based on the Hartmann wave front sensor of microprism array, or based on the Hartmann wave front sensor of microlens array.

5. the little perimeter of adaptive optics according to claim 1, it is characterized in that: described stimulation Optotype presenting apparatus (16) comprises CRT monitor or business projector or colour liquid crystal display device or plasma scope or electroluminescent display or OLED for having the demonstration of the background luminance of regulating screen and sighting target brightness, size.

6. the little perimeter of adaptive optics according to claim 1 is characterized in that: described pupil camera (19) is infrared digital video camcorder.

7. the little perimeter of adaptive optics according to claim 5 is characterized in that: described stimulation Optotype presenting apparatus (16) has regulates the function that stimulates the sighting target color.

8. the little perimeter of adaptive optics according to claim 1 is characterized in that: the adjusting of position is carried out by person under inspection's head fixed support in the position of described human eye (5).

9. the little perimeter of adaptive optics according to claim 1 is characterized in that: the used lighting source of described pupil camera (19) imaging is infrared light supply at the moment, comprises infrarede emitting diode or Array array infrared light supply.

10. the little perimeter of adaptive optics according to claim 7 is characterized in that: described stimulation sighting target is the photostimulation of the of short duration flicker of impulse form.

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