摘要:
A device for swept-source optical coherence domain reflectometry (SS OCDR) on moveable samples, particularly human eyes, for obtaining A-scans, having a measuring range according to the sample length and having a laser light source which can be adjusted by a main wave number k0 and at least one receiver for the light dissipated from the sample, wherein the sample is illuminated on the sample surface by a measurement beam having a diameter D by way of a coupling device. The light source has a spectral line width of δk
摘要:
The invention relates to a solution for interferometrically measuring the eye length and the anterior eye segment after the optical axis of the measuring system has been aligned with the optical axis of an eye. The device according to the invention for interferometrically measuring the eye length and the anterior eye segment consists of an illumination source, at least one interferometric measuring array with external reference, diverse optical imaging systems, and a control and evaluation unit. The illumination source has high spatial coherence and low coherence of time. Preferably, light is emitted by the illumination device from the NIR range, having a wavelength of 700-1000 nm, for example. Furthermore, an optical imaging system is arranged in front of the eye such that the illumination light impinges on the eye as a nearly collimated beam.
摘要:
A device for performing distance measurements on an eye. The device includes an interferometer, focuses at least one measurement beam records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing the focus in the eye or for varying a polarization state of the measurement beam and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and actuates the adjustment apparatus for displacing the position of the focus or for varying the polarization while recording the backscattered radiation from which the control apparatus generates the A-scan individual signals is being recorded.
摘要:
An ophthalmological measuring system for obtaining biometric data of an eye. with a view to the pre-operative determination of a replacement lens or supplementary lens or refractive operations. The invention includes a combination of a measuring instrument based on ultrasound, an optical measuring instrument, and an evaluation unit, measuring values of the optical measuring instrument and/or of the measuring instrument based on ultrasound being used by the evaluation unit for determining the biometric data of an eye. Furthermore, keratometric and/or pachymetric measurements can also be carried out. The combination of different measuring systems enables a complete examination or diagnosis of a patient on a measuring table, so that the patient does not need to be moved, or have to come back at a later date for more measurements.
摘要:
Combined equipment for non-contacting determination of axial length (AL), anterior chamber depth (VKT) and corneal curvature (HHK) of the eye, are also important for the selection of the intraocular lens IOL to be implanted, particularly the selection of an intraocular lens (IOL) to be implanted, preferably with fixation of the eye by means of a fixating lamp and/or illumination through light sources grouped eccentrically about the observation axis.
摘要:
The invention relates to a method for determining distances in the anterior ocular segment, preferably of the pupils and/or the diameter of the iris, wherein the image of at least part of the eye is recorded and digitized using an imaging device and an array for illuminating the eye. On the basis of said digital image, a center of gravity analysis and the determination of the central point are carried out, especially for the position of the pupils, by conducting an intensity and threshold analysis as rough determination. Based on said rough determination, a fine detection of the position of the edges of the pupil and/or the edges of the iris is carried out. Additionally, the angle between the visual axis and the optical axis of the eye can be determined from the position of a fixed reflection to the center of the pupil and/or the center of the iris.
摘要:
The invention is directed to an arrangement and a method for measuring the anterior segment of the eye using interferometric means. The eye is illuminated by a convergent beam bundle and aligned with the optical axis of the measuring device by generating directional stimuli and accommodation stimuli by means of a display which is mirrored into the beam path.
摘要:
An ophthalmological measuring system, for obtaining biometric data of an eye, provided with the necessary calibration and check devices for monitoring the functionality and the calibration status. The ophthalmological measuring system includes an illumination source for illuminating an eye with light and with a sensor for recording and analyzing back-scattered or reflected light components and a controller. At least one calibration and check system integrated in the ophthalmological measuring system for monitoring the functional and calibration status is provided. A device is also provided which houses the calibration and test structures and which reads off the individual physical data therefrom by an interface. The ophthalmological measuring system is in particular provided for determining biometrical data but can also be used for ophthalmological, dermatological or other devices which require calibration and/or functional checking at regular intervals.
摘要:
The present invention is directed to a solution for measuring geometric parameters in the eye which are required for calculating the refractive power of intraocular lenses. The device according to the invention for axial length measurement which acquires axial length, anterior corneal radii, anterior chamber depth, and other parameters in the anterior eye segment includes a control unit, a first measuring device for determining axial length, and an additional measuring device which acquires a plurality of structures in the anterior segment (such as the cornea, anterior chamber, and lens) and which has at least one illumination unit and at least one image recording unit. By determining additional partial-distance parameters of the anterior eye segments, the IOL can be calculated with high precision even after refractive surgery in which the natural relationship between the radii of the anterior and posterior corneal surfaces is extensively altered by corneal surgery.
摘要:
A testing and calibrating device for optical eye length measurement devices comprising two plano-convex lenses which are arranged in the illumination beam path so as to be oppositely oriented. A neutral filter with a defined transmission is located between these two plano-convex lenses.