32 results about "Corneal vertex" patented technology

A method and apparatus for imaging within the eye is provided whereby a component of eye position is detected using optical imaging data. Tracking eye position over time and correctly registering imaging data for scan locations or using eye position to detect decentration achieves improved imaging. In one embodiment, essentially perpendicular B-scans are imaged sequentially and the corneal arc within each B-scan is analyzed to determine the vertex of the eye. The eye vertex is tracked over pairs of perpendicular B-scans to determine eye motion. In another embodiment, the decentration in the Pachymetry map is removed by correcting for the misalignment of the center of the Pachymetry map and the actual location of the corneal vertex.

The invention discloses an OCT (Optical Coherence Tomography) system for measuring the optical path value of an axis oculi and a method. The system comprises an OCT system light source, an optical fiber coupler, a detection system, a control system, a sample arm component, a reference arm component, a cornea before-and-back position alignment component and an outer eye camera component, wherein the outer eye camera component is used for monitoring an iris of eyes under test, and an operator controls the sample arm component to adjust a corneal vertex to the main optical axis of the OCT system according to the iris; the control system is used for judging the distance from the corneal vertex to an eye objective lens, and the distance from the corneal vertex to the eye objective lens is adjusted to meet the requirement on work of the system by means of the before-and-back adjustment of the sample arm component controlled by the control system; an optical path adjusting component adjusts the optical path of the sample arm component, and thus fundi of different human eyes are matched with the optical path of a reflector of a reference arm of the system to realize the OCT imaging of the fundi; the optical path value LEye of the axis oculi of the human eye can be measured according to the formula: LEye=LRDK1toEc+S+hRetinal. According to the OCT system for measuring the optical path value of the axis oculi and the method, the corneal vertex is accurately positioned, and by combining with the fundus OCT imaging technology, the test result of the optical path value of the axis oculi of the human eye is more accurate.

The invention relates to a cornea center positioning method for excimer laser cornea refractive surgery. In the method, a horizontal offset model and a vertical offset model are established by measuring the pupillary diameter and the offset of the pupillary center relative to the center of the corneal vertex under different luminance brightness, and the data of the established models is input into a laser cornea refractive surgery machine with an eye tracking system, so the pupil in the laser cornea refractive surgery is dynamically tracked, the error of the tracking system is reduced, and the visual quality after the laser cornea refractive surgery is obviously improved.

Methods and systems for determining whether an image is of a left eye or a right eye may be used to enhance laser eye surgery systems and techniques. Methods generally involve locating an iris center and/or pupil center on an image of the eye, locating a corneal vertex and/or at least one reflection on the image, and determining whether the image is of a left eye or a right eye, based on the location of the corneal vertex and/or reflection(s) relative to the iris center and/or pupil center. Systems include a laser emitting a beam of an ablative light energy and a computer processor having a computer program for determining whether the image is of a left eye or a right eye, based on a location of the corneal vertex and/or reflection(s) relative to the iris center and/or pupil center.

The invention discloses a corneal vertex alignment method, which comprises the following steps of judging a corneal vertex to be located in a vertical plane on which a principal optic axis of an ophtalmological optics system is located according to a cornea position alignment module in a vertical direction, judging the corneal vertex to be located in a horizontal plane on which the principal optic axis of the ophtalmological optics system is located according to a cornea position alignment module in a horizontal direction, and confirming the corneal vertex to be located on the principal optic axis of the ophtalmological optics system; judging the corneal vertex to be located in front of or in rear of a working position arranged by the ophtalmological optics system according to the cornea position alignment module in the vertical direction or the cornea position alignment module in the horizontal direction; moving the corneal vertex to the working position. The invention also discloses a corneal vertex alignment system, an OCT (Optical Coherence Tomography) system for applying the method to eye axis optical path length measurement, and an eye axis optical path length measurement method. According to the invention, the perfect alignment of the corneal vertex is realized, and the accurate measurement of the eye axis optical path length is realized on the basis.

The invention discloses a method for accurate alignment of a corneal vertex. The method comprises the steps that (1), the pupil of a tested person is found through iris imaging, and the center of the pupil is adjusted to be nearby the center rendezvous point of a plurality of scanning lines of a scanning device; (2), the scanning device scans the pupil of the tested person, a computer processing scanning data, and then a pupil OCT is obtained; (3), the computer computes the distance L between a center reflection column in the pupil OCT and the center line of the pupil OCT; (4), the amount of movement of the head of the tested person or the scanning device is computed according to the scanning angle theta of the scanning lines and the distance L, the head of the tested person or a probe of the scanning device is moved, and the corneal vertex of the tested person is made to accurately align with a main optical axis of a system light path. The method has the advantages that the accurate alignment of the corneal vertex is achieved, the adjusting method is simple and rapid and can be divided into automatic adjusting or semi-automatic adjusting, the adjusting modes are various, and operation is easier.

The invention discloses a method utilizing ophthalmology equipment for detecting the exophthalmic degree and ophthalmology equipment. The method comprises the steps that the first distance X1 from a system reference point St of the ophthalmology equipment to the eye outer side frame edge Ek in the front and back direction, the second distance X2 from a system probe of the ophthalmology equipment to the system reference point St in the front and back direction, and the third distance X3 from the corneal vertex Ec to the system probe in the front and back direction are obtained, and the exophthalmic degree is obtained according to an equation Delta=X1+X2-X3; the ophthalmology equipment mainly comprises the system probe, a cornea position locating module, an eye outer side frame edge locating device and an eye outer side frame edge locating device connecting mechanism. A primary optical axis of the system probe is aligned to the corneal vertex Ec. The cornea position locating module is used for locating the corneal vertex Ec and measuring the third distance X3 from the corneal vertex Ec to the system probe. The eye outer side frame edge locating device is used for imaging the eye outer side frame edge. According to the method and the equipment, the exophthalmic degree is detected through a non-contact mode, and cross infection is avoided.

The invention discloses an image processing method for obtaining corneal vertexes. The method comprises the following steps of continuously acquiring N frames of images at a high speed to synthesize aframe of image with minimum noise; acquiring a potential corneal reflection area through image binaryzation and blob analysis so that a to-be-processed area is reduced; carrying out gray stretchingon the potential light spot area; carrying out double-threshold binarization and blob analysis; obtaining a gray gravity center and a light spot boundary coordinate of a cornea vertex area; taking a gray vertex as a center; pulling the ray outwards every a certain angle to obtain a gray sequence on the ray; carrying out gaussian fitting based on a nonlinear least square method on gray scale data of the strip ray group to acquiresub-pixel coordinate values of corneal vertexes; finally, according to the jump of the gray value on the ray at the boundary; solving a sub-pixel-level coordinate boundary; corneal vertex and light spot boundary information obtained through the method can be combined with pupil center position and other related information obtained through other devices to obtain Kappa angle Alpha angle and other related information of eyes, and reliable basic data are provided for subsequent further eye refraction parameter obtaining.

The invention provides an eyeball protrusion measuring instrument and measuring method. The eyeball protrusion measuring instrument comprises a base, a support, a baffle, a measuring assembly, a fixing assembly and a control assembly, wherein the fixing assembly is used for fixing the head of a testee, and the measuring assembly comprises a track, a distance measuring sensor, a light emitter and a first driving part; and the eyeball protrusion measuring method uses the eyeball protrusion measuring instrument to measure the eyeball protrusion of the testee. According to the eyeball protrusion measuring instrument and measuring method, the light emitter emits visible light to assist in calibrating the position of the bitamporal orbital marginal bone of a testee, and the control assembly controls the first driving part to drive the distance measuring sensor to move on the track, so that eyeballs of the testee are automatically scanned, the cornea vertex is recognized, and errors caused by manual operation are avoided; and besides, the measuring environment of the left eye and the right eye is isolated through the baffle, so that the situation that the measuring result is wrong due to inconsistent eyeball protrusion is avoided, and the measuring precision of the eyeball protrusion is effectively improved.

Disclosed is a method for determining the position of the eye rotation center of a subject's eye including: providing a geometric model of an eye, the eye being modeled with one sphere for the sclera and one ellipsoid for the cornea of the eye, the position of the eye rotation center being the distance between a center of the sclera and an apex of the cornea and being determined based on a set of personal parameters including a first geometric dimension of the eye, each personal parameter distinct from the position of the eye rotation center; determining a value of each personal parameter; and determining a first approximate value of eye position rotation center based on the geometric model using the personal parameters. Also disclosed is a method for calculating a personalized ophthalmic lens for the eye using such center, as well as a device implementing this method.

The invention discloses a calculating system for IOL rear surface average value after corneal refraction operation, and the system comprises a calculation origin selection module and a calculation module; the calculation origin selection module comprises a corneal vertex and a pupil center point, and the corneal vertex corresponds to a curvature average value in a first range, a curvature average value in a second range and a curvature average value in a third range; the pupil center point corresponds to the curvature average value on the first ring, the curvature average value on the second ring and the curvature average value on the third ring, and the calculation module comprises a first calculation formula and a second calculation formula. Compared with the prior art, the method has the advantages that the mean value of the curvature radiuses of the rear surface is calculated by calculating the mean value of the curvature radiuses of the multiple points, so that the accuracy of calculation of the curvature radiuses of the rear surface is improved.

The invention discloses a laser navigation-based gas injection control method for blink reflection measurement, which comprises a laser navigation module, a signal transceiver, a main control chip, a camera, an information analysis module, a compressed air generation module and a data storage module connected with the main control chip, the camera is used for judging whether the left eye and the right eye are open or not, the laser navigation module is used for measuring the distance between a nozzle of the compressed air generation module and the vertex of the cornea and transmitting distance parameters to the signal transceiver, and the signal transceiver transmits data to the main control chip after receiving signals. The device is used for checking blink reflex, space and time distribution of air injection pressure in front of the cornea of the left eye and the right eye can be consistent, the pressure and time of triggering the blink reflex by the two eyes are consistent, recording of the blink reflex is facilitated, measurement of the blink reflex can be started at any time without waiting for blink of the eyes, and non-contact measurement and automatic measurement are achieved. Multiple measurements are realized and the efficiency is high.

The invention provides a cornea surface morphology measuring device and method. The cornea surface morphology measuring method comprises the steps that firstly, a cornea image containing dot matrix light spots is obtained through a binocular camera system, then three-dimensional coordinates of each measuring point are calculated through coordinate conversion, and all the three-dimensional coordinate points are subjected to a curved surface fitting method to obtain an approximate spherical surface where the cornea is located; finally, the Gaussian diopter at each measuring point is calculated, and a data field interpolation method, color coding and other operations are combined to generate the corneal topographic map. According to the invention, the Gaussian diopter of the corneal vertex position does not need to be determined to serve as a numerical form of the corneal topographic map, corneal center alignment does not need to be conducted, and compared with an existing method, the operation is easy and convenient; the invention is low in cooperating requirement for infants; the device can be integrated into a handheld end, is suitable for cornea detection of the infants, and facilitates screening of early eye diseases.

The invention provides a Placido disc design method based on a simulated annealing algorithm, which comprises the following steps: presetting the distance from a corneal vertex to a Placido disc vertex in a corneal topography instrument and the distance from the corneal vertex to a diaphragm in the corneal topography instrument as initial conditions for subsequent optimization; setting an expression corresponding to the surface type of the Placido disc; calculating an aberration function at the diaphragm according to an aberration principle; and performing simulated annealing operation by taking the aberration function as an evaluation function and the Placido disc surface parameter as a variable, and calculating to obtain the Placido disc surface parameter when the aberration is minimum. The Placido disc formed through calculation of the method has the advantages that the small aberration is achieved at the diaphragm, the design difficulty of a follow-up lens group is reduced, and the follow-up image processing precision can be improved.

The invention relates to a computer-implemented method that detects the position of a corneal vertex from a frontal image of a head and a lateral image of the head. The front and lateral images are calibrated to one another, and the position of the corneal vertex in space is determined from the frontal image and the lateral image with a geometric position determination.

A method for generating a radial alignment guide for an eye includes collecting preoperative corneal topography data. The data includes a corneal vertex location and a pupil center location for an eye that is not dilated. The method then includes locating a dilated pupil center for the eye after the eye is dilated. The method further includes determining an adjusted offset between the corneal vertex and the dilated pupil center and displaying alignment data on an image of the eye based on the adjusted offset.

The invention discloses a computer optometry unit. The computer optometry unit comprises a fogging light path and a focusing light path, and is characterized in that the focusing light path comprises a laser, a first light source lens, a second light source lens, a PBS, a first spectroscope, a second spectroscope, an objective lens, a first focusing lens, a second focusing lens, a telecentric diaphragm, a cornea objective lens and a first detector. The second spectroscope, the PBS, the first light source lens, the second light source lens and the laser are located on a first optical axis and are sequentially arranged on the same optical axis, the first spectroscope, the objective lens and the second spectroscope are located on a second optical axis and are sequentially arranged on the same optical axis, and the first spectroscope, the telecentric diaphragm, the cornea objective lens and the first detector are located on a third optical axis and are sequentially arranged on the same optical axis. The first focusing lens and the second focusing lens are symmetrically arranged along the third optical axis and are located between the first spectroscope and the telecentric diaphragm. The unit has the advantages that whether the vertex of the cornea is focused or not is judged simply, visually and accurately, the focusing accuracy of the vertex of the cornea is improved, and high-precision and high-repeatability measurement of human eyes is realized.

An optometric apparatus for subjectively examining visual functions of an eye (PE) of an examinee is disclosed. This apparatus includes: a disposing unit (2) for disposing an optical element (4) in front of the examinee's eye; a cornea position alignment optical system (20) for checking a vertex distance between a back surface of the disposed optical element and a corneal vertex of the examinee's eye; wherein the alignment optical system includes an aligning scale plate (23) provided with a scale (S1–S5) for checking the vertex distance, a reticle plate (24) provided with a reticle (24a) and placed in a different place from the aligning scale plate, and a first reference mark (30) and a second reference mark (31) for positioning an eye (OE) of an examiner in a point at a predetermined distance from the reticle plate, the first and second reference marks being provided in different places and appearing, to the examiner's eye, to have a predetermined positional relation with each other when the examiner's eye is positioned in the point at the predetermined distance from the reticle plate.