Abstract: An improved ophthalmic instrument including a wavefront sensor that estimates aberrations in reflections of the light formed as a spot image on the retina of the human eye, wherein the wavefront sensor includes at least one subaperture that spatially samples incident light; at least one optical element that focuses each sample to a spot; and an image sensor and image processor for measuring location of the spot. The image sensor captures image data of an pixel subaperture defined around the spot and provides the image data to the image processor. The image processor analyzes the image data to identify a subarray of pixels around a peak in the pixel subaperture, fits a predetermined function to the image data for the subarray of pixels, and derives an estimate for spot location based upon location of the fit of the predetermined function.
Abstract: A method of monitoring a subject for medical conditions includes causing light to impinge on at least one eye of the subject, directing reflected light from such light beam to photosensors, converting the received reflected light to corresponding electrical signals which are delivered to a processor. Processing the signals by effecting a comparison between stored information regarding the medical condition and the data provided by the monitoring to determine if an undesired medical condition exists and, if so, communicating such result. The cycle is repeated at predetermined intervals which may be short or prolonged. The stored information may be information relating to the specific subject or general information regarding normal and abnormal conditions of the eye representative of toxicity. The eyes may be monitored sequentially or simultaneously. Related apparatus is provided.
Type:
Grant
Filed:
August 17, 2001
Date of Patent:
October 14, 2003
Assignee:
West Virginia University
Inventors:
James V. Odom, James E. Smith, Robert P. M. Craven
Abstract: The present invention provides an eye characteristic measuring apparatus provided with an image forming condition changing unit for achieving an appropriate illuminating condition and capable of setting an optimum illuminating condition and an optimum light receiving condition.
Abstract: A device for assisting the development of an infant's visual acuity and for transferring the mother's scent to an infantile environment. Supple fabric contacts an area of the mother's body for absorbing a portion of the mother's scent and is thereafter transferred and attached to the infantile environment for venting the transferred scent about the infantile environment. The supple fabric is also includes a contrasted black and white pattern for assisting the development of the infant's visual acuity. A second side of the device can be supplied with a neutral color.
Abstract: A method of monitoring a subject for medical conditions includes causing light to impinge on at least one eye of the subject, directing reflected light from such light beam to photosensors, converting the received reflected light to corresponding electrical signals which are delivered to a processor. Processing the signals by effecting a comparison between stored information regarding the medical condition and the data provided by the monitoring to determine if an undesired medical condition exists and, if so, communicating such result. The cycle is repeated at predetermined intervals which may be short or prolonged. The method may be employed for a wide variety of medical conditions and preferably is employed with frequent cyclic monitoring for conditions such as miosis, carbon monoxide poisoning, and blood flow related conditions. A related apparatus is provided.
Type:
Grant
Filed:
May 18, 2001
Date of Patent:
September 30, 2003
Assignee:
West Virginia University
Inventors:
James Odom, James Smith, Robert Craven, Ahmed El-Sherbeeny
Abstract: A method of deriving a prediction model and calculating a predicted lens power to provide a desired post-operative spherical equivalent to correct myopia in a phakic eye of a patient using an intraocular lens includes measuring and determining the predictive significance of certain pre-operative characteristics of the eye, including cycloplegic and manifest spherical equivalent, vertex distance, anterior chamber depth, and keratometry. The prediction model is derived using multiple regression analysis on the pre-operative and post operative data. Measured data corresponding to a particular patient is used in the lens power prediction model to calculate the predicted lens power for implantation in the patient.
Abstract: A device and method for providing a stimulus to the measurement of the field of vision of the human eye. The stimulus is presented at predetermined test sites in a region of the background of a perimeter to a person to be tested. The stimulus has at least two visual characteristics that can be varied for the determination of a threshold. The stimulus is preferably formed by sine waves.
Abstract: A method and apparatus for detecting diseases and abnormalities of a patient's eyes is disclosed. The apparatus includes an image-recording device for recording images of the patient's eyes while illuminated with infrared light and while at least two different meridians of the patient's eyes are illuminated with visible light in a time period shorter than the response time of the patient's eyes. The apparatus further includes a light source for illuminating the patient's eyes with infrared and two different meridians of the patient's eyes with visible light, and a control system for controlling the image-recording device and the light source. In one embodiment, the image-recording device includes a high-speed digital camera, the light source includes a group of infrared light-emitting diodes (LEDs) and a pair of flashes, and the control system is a computer system. The invention is useful in detecting both refractive and non-refractive errors of the eyes.
Abstract: An eye examination device includes an eye examination unit for examining or measuring an eye of an examinee; a carrying case including a first housing part for housing the eye examination unit and a base part which mounts thereon the eye examination unit; a horizontal movement unit which moves the eye examination unit in a horizontal direction with respect to the base part; and a vertical movement unit which moves the eye examination unit in a vertical direction with respect to the base part.
Abstract: An improved method for treating the eye includes the step of providing an ophthalmic instrument including an integral wavefront sensor. The wavefront sensor measures phase aberrations in reflections directed thereto to characterize aberrations of the eye. The wavefront sensor may be operably coupled to a display device, which displays a graphical representation of the aberrations of the eye. Such graphical representation may include: two dimensional contour maps that graphically depict contribution of pre-specified terms (such as spherical aberration, astigmatism and coma) for the aberrations of the eye, coefficients corresponding to such pre-specified terms that characterize the aberrations of the eye, or predefined two-dimensional icons that provide a general graphical depiction of such pre-specified terms.
Abstract: A hybrid tracking system is configured to combine the advantages of open loop and close loop tracking systems. The hybrid tracking system employs a position-sensing device in an open loop configuration, while the position-sensing device itself is a close loop device. A particular application of this tracking system is to track eye movement in a refractive laser surgery. The hybrid-tracking configuration enables optical and mechanical separation of the position-sensing device from the surgical laser beam. As a result, the position-sensing device can be made as a modular device, and the hybrid eye-tracking system can have a relatively large tracking range even when a curved mark such as the limbus is used as the tracking reference.
Abstract: An apparatus (10′) for detecting the surface topography of a cornea (24) of an eye (22) by dynamic or static projection of a pattern onto the surface of the cornea and detection of the pattern reflected by the cornea, providing preferably simultaneous detection of at least one optical property of a layer disposed beneath the cornea.
Type:
Grant
Filed:
July 30, 2001
Date of Patent:
August 5, 2003
Inventors:
Benedikt Jean, Thomas K. Bende, Adolf F. Fercher
Abstract: Optical characteristics, including vision defects, of optical systems, such as the eye, are measured using a collimated beam from a diode laser focused at a position relative to the eye other than the retina for providing a finite source of secondary radiation on the retina of the eye, the image of which is close to a desired diffraction-limited spot. The secondary radiation is reflected back from the retina as a reflected wavefront of radiation that passes through the eye and is directed onto a wavefront analyzer where distortions associated with the reflected wavefront are measured. By focusing on the cornea through a long-focal-length lens and thus converging the beam through a small angle, as opposed to focusing a collimated light onto the retina, the need for lenses or lens combinations and the time required to adjust such to accommodate the different visual characteristics of each patient is eliminated.
Abstract: An apparatus and method for measuring wavefront aberrations. A beam splitter separates the aberrated wavefront into two components, mirror arrays focus each of the components to a plurality of discrete lines with the discrete lines of one component having a different orientation than the discrete lines of the other component, and an imaging device detects the discrete lines to determine wavefront aberrations. The method includes separating the wavefront into two components, focusing each of the components into a plurality of discrete lines with the discrete lines of one component having a different orientation than the discrete lines of the other component, and detecting information related to the discrete lines.
Abstract: A system and method improve a quality of sensor image data from a wavefront emanating from an eye. The sensor image data include a pixel array of intensities. A filter array is populated with a coefficient at each position of the array and the filter array is applied to each position in the pixel array. The system includes a process and a software package adapted to perform the above method steps.
Abstract: An improved ophthalmic imaging instrument including a wavefront sensor-based adaptive optical subsystem that measures phase aberrations in reflections derived from light produced by an imaging light source and compensates for such phase aberrations when capturing images of reflections derived from light produced by the same imaging light source. The high-resolution image data captured by the improved ophthalmic imaging instrument can be used to assist in detection and diagnosis (such as color imaging, fluorescein angiography, indocyanine green angiography) of abnormalities and disease in the human eye and treatment (including pre-surgery preparation and computer-assisted eye surgery such as laser refractive surgery) of abnormalities and disease in the human eye.
Abstract: Proposed is a method and a device configuration for determining the corneal thickness of an eye, in particular of a human eye, by means of light rays. First light rays are projected onto and into the cornea, and second light rays, reflected by the cornea, are registered for determining the corneal thickness. A contact element, which is preferably plane-parallel, is placed on the contact area of the cornea, and the first light rays are projected through the contact element onto and into the cornea. The contact element is fixed on the cornea, for example. The first light rays are projected at least in points in a two-dimensional measuring area of the flattened area onto and into the cornea, and the corneal thickness is determined at one or more places of the measuring area.
Abstract: A method of producing intra-ocular lenses or contact lenses including the following steps:
a) mechanically forming a lens blank such that it is suitable for correcting an ametropic visual defect,
b) measuring the aberration of an eye to be corrected,
c) calculating an ablation profile with respect to the lens blank on the basis of the measured aberration, and
d) ablating material of the lens blank in accordance with the calculated ablation profile by means of laser radiation.
Abstract: A modular fundus camera including an adaptive optical module that detachably interfaces to a fundus camera body and image capture subsystem. The fundus camera body directs light produced from a first light source into the human eye and then collects and collimates retinal reflections. The adaptive optical module includes a wavefront sensor, controller and phase-compensating optical element. The wavefront sensor measures phase aberrations in the retinal reflections and operates in a closed-loop fashion with the controller to control the phase-compensating optical element to compensate for such phase aberrations to produce phase-compensated retinal reflections for output to the image capture subsystem.
Abstract: A system and method for objectively testing for ocular changes including age-related macular degeneration through reliance on involuntary physical reactions such as the fixation reflex and optokinetic nystagmus. A narrow band of visible blue light is beamed at the patient's eye through alternate apertures in a mask which are separated by a relatively small angle of subtendance at the entrance pupil. In the presence of a healthy macula, the blue light is filtered out and the fixation reflex is absent. Conversely, if the macula is in the process of degenerating by the progressive loss of protective pigments, then the impinging of the narrow band of visible blue light upon the macula, via the alternate apertures, will evoke the fixation reflex.