Abstract: The present invention provides a method for establishing fixation during computerized visual field perimetry, requiring the subject to verbally identify the symbol employed as fixation targets as they each appear. Speech recognition techniques are then employed to evaluate the subject's response, and, upon correctly identifying the fixation symbol, a visual test stimulus is displayed at a predetermined location within the subject's field of vision. Fixation is established by displaying to the subject fixation targets represented by varying symbols, which may be displayed at one or more locations on a display monitor. These so-called fixation symbols, include geometrical shapes, letters, numbers, pictures or other symbols readily identifiable by the subject. When a fixation symbol appears, the subject verbally identifies the symbol by saying the name of the symbol into a microphone.

Abstract: A novel visual field test utilizing oscillating visual stimuli is proposed, which may be used to diagnose for eye disorders, such as glaucoma or macular degeneration. Such visual stimuli oscillate in color, polarity, saturation, luminance or intensity. Preferably, the visual test pattern consists of oscillating visual stimuli arranged in a pattern, such as a repeating or grid pattern, covering substantially all of the field of vision being tested. And, may include the use of frequency doubling visual stimuli. In use, the visual field test pattern is positioned in front of the patient so as to cover substantially all of the field of vision being tested, typically about a solid angle of 40° or more. The eye under examination is fixated, and the patient asked to indicate areas where the oscillating visual stimuli are dissimilar, such as by outlining those areas different from the rest of the visual field test pattern.

Abstract: The invention provides a scalable, automated, network friendly method for building parallel applications from embarrassingly parallel serial programs. Briefly, the steps of an exemplary method in this invention are as follows: First, the application loops with significant potential parallelism are identified. Second, from the set of loops identified, those loops which can statically be shown to not be parallelizable are disqualified. Next, the program is transformed into a parallel form in which the remaining identified loops are optimistically parallelized and packaged into per-iteration functions. Then, shared memory in the functions is relocated to a shared memory section available to all computers and references to the shared memory in the source code are transformed into indirect accesses. Finally, the per-iteration functions are spawned on to multiple computers, at run-time, where each computer is given a range of iteration.

Abstract: The present invention is directed to an optical time-domain reflectometer which employs a so-called “out-of-band” offsetting to cancel the effects of Raman non-linearities which extract energy from the traffic signal wavelengths and amplify the test signal back-scattering. Losses and faults in the optical fibers are monitored by measuring the back-scattered portion of the light launched into the fiber, with the test signal back-scattering judiciously offset to account for the Raman non-linearities. That is, the effects of the Raman non-linearities are taken as a baseline measurement and, then accordingly used as a basis to offset the test signal back-scattering.

Abstract: The present invention employs polarizers and delay elements to effect the real-time measurement of optical parameters required to compute the polarization mode dispersion (PMD) in an optical fiber. The measurement is performed in situ and based on the remote sensing of the intensity levels of optical pulses transmitted through two polarizers deployed along the fiber for different known states of polarization at each of two wavelengths. In as much as information about the output states of polarization of the optical pulses contained in these latter intensity transmission measurements are made substantially coincident with the location of the polarizers, the return propagation of the optical pulses does not affect the measured polarization characteristics of the fiber.

Abstract: This invention relates to a method for computing the average data transmission rate available in each channel in a data communication, TCP/IP system that utilizes in part cable television channels as the transmission media. The method employs a bandwidth manager and a test personal computer, both of which are connected to the cable channel system to determine the average bit rate through any channel in the system. By utilizing computers connected to the cable system to make bit rate measurements, the problems associated with having a low speed telephone link that dominates the measurement is avoided.

Abstract: A limitation of modeling three-dimensional objects in a virtual world occurs when a user moves within the world and still wishes a certain target object to remain visible, instead of being occluded by other surfaces in front of the object along the direction the user is viewing the target object. Therefore, in accordance with the principles of the invention, a target object which is to remain visible, regardless of the user's view point, is duplicated and modeled as being located a close distance to the user, but scaled accordingly to make the cloned object appear to be farther away from the viewpoint of the user and co-located with and of the same size and orientation as the target object. In this manner, as the user moves within the world, surfaces located in front of the target object do not occlude the cloned object from the user's view, thus appearing to give that same property to the target object.

Abstract: The present invention is an optical spectrum analyzer (OSA) comprising a tree-structure of N-stage wavelength filters or “wavelength slicer” which “slice” the incident optical signal into desired groupings of individual sliced spectral components, each along a different output optical fiber. Cascaded fiber Bragg gratings and delay lines coupled to each output optical fiber then uniquely map the “sliced” spectral components into the time domain such that each spectral component is allocated a unique time slot.

Abstract: In accordance with the teachings of the present invention, it has been discovered that an optical analysis that is uniquely based on geometrical rather than diffraction considerations, for the purposes of controlling the size of the region from which the photoluminescence is collected, provides an optical system capable of performing photoluminescence microscopy and/or spectroscopy without the disadvantages of the prior art. It is based, in part, on the use of an optical fiber(s) as a field stop within the detection arm(s) of the optical system for coupling the photoluminescence into an optical spectrum analyzer (OSA) and/or photodetector, wherein the diameter and the numerical aperture of the optical fiber are judiciously chosen to limit the field of view, or the region from which the photoluminescence is collected.

Abstract: The present invention employs “polarization markers” deployed immediately after the branching portion of a passive optical network (PON) for measuring and monitoring transmission losses and faults. Each polarization marker is configured to produce a unique polarization dependent loss (PDL) within the corresponding branch of the PON. Since each polarization marker uniquely attenuates optical test pulse(s) launched into the PON, the back-scattering uniquely varies with the launched state of polarization. Losses within each branch of the PON are then monitored by measuring the back-scattered portion of the launched optical pulse(s) as a function of time for different known states of polarization, wherein the unique PDL associated with each polarization marker is used as the basis for distinguishing the branches from one another.

Abstract: The present invention is a de-icing system that uses electro-magnetic actuators mounted within the airfoil of an aircraft to effect de-icing. Advantageously, the actuators have low-energy requirements. Each actuator includes conductive strips fabricated on a flexible dielectric sheet. The conductive strips are wound into coils with the actuators shaped into a flattened elongated tube. The axis of the winding coils is coincident with the longitudinal axis of the elongated tube. Low adhesive coatings may be used to enhance the efficiency of the electro-magnetic coils in expulsing the ice accretion.

Abstract: A novel psychophysical visual test is proposed for testing a person for glaucoma, and based on the discovery that a frequency doubling phenomenon is produced by isoluminent color visual stimuli. More specifically, it is proposed to construct a visual stimulus for which alternating colors in a grating pattern is the only basis for producing the frequency doubling phenomenon. That is, the colors are of the same luminance or intensity level, i.e., isoluminent, but each grating or pattern alternates from one color to another. Preferably, the colors are complementary color pairs, such as blue and yellow.

Abstract: A technique for evaluating the topography of a cornea in which a virtual object of a keratoscope pattern isured. The topography system includes a structured light source to create the keratoscope pattern or another diagnostic pattern, an optical assembly to focus the created pattern upon or behind the cornea, and for capturing the image reflected off the patient's eye and directing the reflected image toward an imaging system for processing. Light emitted by the light source is preferably not in the visible range, to minimize discomfort to the patient. Since the topography is evaluated with a projected virtual image, there is no nose or brow shadow, thereby allowing better corneal coverage. The optical system includes an aperture stop which is preferably conjugate with a point behind the corneal surface approximating the center of a normal cornea. Thus, wide angle capture is achieved as reflected rays reaching the imaging system appear as if they originated at the center of the cornea.

Abstract: The present multi-functional, visual test instrument is realized by integrating miniature, close-proximity displays, such as LCDs, with viewing optics, which is constructed in the form of preferably a unitary housing. In a preferred embodiment, the multi-functional, visual test instrument includes two viewing assemblies, and displays, which are all enclosed in the housing that is slidably or pivotally attached to a movable mount, such as a slit lamp base. In operation, various optical test objects or stimuli are viewed by the patient on the displays through the viewing assemblies. The shape, size, speed, frequency, location, color, contrast and intensity of the test objects or stimuli are computer generated. A hand operated switch, mouse, joystick, or other input means, may be used for the patient to respond to the observed test objects or stimuli.