Abstract: In a laser beam delivery system for a surgical laser beam, steering and scanning of the laser beam along the target in transverse (X and Y) directions is accomplished in a mechanically simple and fast-responding manner. Closely adjacent to the objective lens assembly of the delivery system is a pair of prisms, i.e. a Risley prism or Herschel prism, positioned on the axis of the approaching laser beam. The two prisms, closely spaced, are mounted on separate rotating stages whereby they may be individually rotated about the beam axis. When the prisms are co-rotated, circular scans are produced on the target, in diameters depending on the angular phase between the prisms. Counter rotation of the prisms at equal and opposite speeds will produce a diametric line scan on the target. Any desired complex scan pattern can be achieved using combinations of rotations of the two prisms.

Abstract: A system and method for detecting, measuring and correcting for movements of a target in a medical analytic or surgical system utilizes generally the principles of confocal microscopy. A pinhole and photodetector combination is positioned behind optics of a system for delivering an ophthalmic surgery laser beam, for example. As in a confocal microscope, the optics are arranged such that a beam waist is formed precisely at the pinhole when the target is in its nominal position. When the target moves from its nominal position in the depth direction, the signal from the pinhole/photodetector combination decreases. The change in the signal can be used to drive the objective lens of the optics so as to move with the moving target. Alternatively, the signal can be used to drive the pinhole/photodetector assembly so as to again attain peak signal, in this way allowing the target's shift to be measured.

Abstract: An improved apparatus and technique are disclosed for illuminating the cornea with points of light for analysis of the specularly reflected return light in determining the shape of the cornea. In combination with an optical illumination system which forms real images of points of light inside or in the path of the objective lens, the system of the invention includes a plurality of real light source points optically peripheral to the real image points and physically outside to the objective lens. The sources of the point light sources may be optical fibers or LEDs arranged in an array which optically extends radially outward from the objective lens, although the external points may be forward or back from the objective lens. The two types of point light sources are generally registered in a pattern and together form an ordered geometric array for providing paraxial reflections off the cornea over a wide area of the cornea, including both central and peripheral areas of the cornea.

Abstract: The present invention describes a technique and apparatus for finding spots in an image with substantial noise making it difficult to identify without specialized noise suppression algorithms. In the context of determining corneal shape, as an example of the technique, the reflections of point light sources in or on the cornea have long played a diagnostic role. The image analysis technique described applies the tools of mathematical morphology and prior information about the shape of illumination patterns to remove noise and isolate the points of interest for further mathematical analysis. The output from the technique is a set of pairs matching the detected points in the image with the known location of the illumination.

Abstract: A system and method for detecting, measuring and correcting for movements of a target in a medical analytic or surgical system utilizes generally the principles of confocal microscopy. A pinhole and photodetector combination is positioned behind optics of a system for delivering an ophthalmic surgery laser beam, for example. As in a confocal microscope, the optics are arranged such that a beam waist is formed precisely at the pinhole when the target is in its nominal position. When the target moves from its nominal position in the depth direction, the signal from the pinhole/photodetector combination decreases. The change in the signal can be used to drive the objective lens of the optics so as to move with the moving target. Alternatively, the signal can be used to drive the pinhole/photodetector assembly so as to again attain peak signal, in this way allowing the target's shift to be measured.

Abstract: A diagnostic system for support of laser ocular surgery, for example, solves a problem of competition for light which is often encountered when a series of different detectors are used to receive and detect features of a target reflecting an illuminating light beam. The intensity of an illuminating beam, particularly in eye surgery, is limited to a level above which damage to the eye can occur. In a system wherein a plurality of successive beam splitters are used, each reflecting a portion of the light intensity and transmitting the remaining light intensity, the series of detecting devices compete for adequate light intensity for the particular functions being served. The system of the invention solves this problem and increases the effective quantity of light useful from a given input intensity by dividing the light spectrally after its reflection from the eye, thereby making use of a different spectral range of the light at each of the plurality of different detecting devices.

Abstract: A system for effecting precision laser surgery includes an intensified surgical video microscope directed at the tissue to be operated upon and having zoom capability. The surgical microscope presents a microscopic image on a video screen in front of the surgeon. Preferably, the video screen is divided into multiple separate sections, with the microscopic video image in one section and precise cross sectional and plan views indicating location presented in the other sections of the screen. These additional views may be generated using Moire interferometry by projecting a Ronchi ruling on the surface of the tissue, in viewing the projection with a camera to obtain all necessary information for contour tracking of the subject surface. Interior elements and interfaces of, for example, the eye are also sensed by a light beam and precisely located and mapped by a computer forming a part of the device.

Abstract: An ophthalmic diagnostic instrument determines the shape of the cornea through projection of an image onto the cornea through the optics of the diagnostic instrument. The instrument and the method of the invention involve folding a projected pattern of discrete separated point light sources so that the pattern is projected toward the eye coaxially with return collected light reflected off the cornea. The instrument avoids any need for a pattern light source directly adjacent to the eye, and provides the surgeon or other eye care specialist with a real time image accurately displaying the shape of the cornea. The surgeon is thus able to monitor the corneal shape prior to surgery, to monitor its changes during the course of the surgery, and to further monitor the cornea in post operative stages.

Abstract: A diagnostic system for support of laser ocular surgery, for example, solves a problem of competition for light which is often encountered when a series of different detectors are used to receive and detect features of a target reflecting an illuminating light beam. The intensity of an illuminating beam, particularly in eye surgery, is limited to a level above which damage to the eye can occur. In a system wherein a plurality of successive beam splitters are used, each reflecting a portion of the light intensity and transmitting the remaining light intensity, the series of detecting devices compete for adequate light intensity for the particular functions being served. The system of the invention solves this problem and increases the effective quantity of light useful from a given input intensity by dividing the light spectrally after its reflection from the eye, thereby making use of a different spectral range of the light at each of the plurality of different detecting devices.