Abstract: A medical diagnostic method using systolic and diastolic blood pressures, and pulse frequency of a patient is provided to compute a normalized diastolic distensibility value and a normalized peripheral resistance value, and to automatically compute the product of the normalized diastolic distensibility value and the normalized peripheral resistance value to generate a first product value. The first product value is compared to a stored distribution of normalized diastolic distensibility and a normalized peripheral resistance values for comparable individuals to determine if the first product value is equivalent to a value determined to indicate an abnormal condition. Particular values of the computed parameters aid in determining the etiology of hypertension and direct selection of pharmacotherapy.

Abstract: An adiabatic liquid volume sensor system is described, which employs a main chamber in a back-to-back configuration with a reference chamber of known volume. The system measures liquid volume in the main chamber by making low frequency acoustic measurements of the acoustic pressure differences in the two closed chambers when driven with a sinusoidal frequency from the same speaker. Pressure transducers in each chamber measure acoustic adiabatic pressures in each chamber. The ratio of these pressures multiplied by the known volume of the reference chamber yields the volume of gas in the main chamber. The volume of liquid is equal to the known volume of the main chamber minus the calculated gas volume.

Abstract: Ultrasound induced by RF irradiation within FDA exposure limits is produced with sufficient signal-to-noise ratio to allow acquisition of sub-millimeter resolution images within practical time frames.

Abstract: A system and method for sorption and desorption of molecular gas contained by storage sites of graphite nano-filaments randomly disposed in three-dimensional reticulated aerogel.

Abstract: A method of marking and identifying an object (10) by the marking consists of applying to an object (10) an up-conversion material (12), then irradiating the object (10) with infrared electromagnetic radiation (16) and, finally, observing the irradiated object to detect the spectrum of emitted electromagnetic radiation (18). A suitable up-conversion material (12) is selected from a group of up-conversion materials consisting of CaF2, BaF2, CdF2, LaF2 and SrF2 doped with erbium, praseodymium, neodymium or dysprosium. The objects (10) may be observed to detect emitted electromagnetic radiation (18) from that part of the electromagnetic spectrum that is visible to the naked eye. The objects (10) may also be observed to detect specific wavelengths of electromagnetic radiation which are known to be emitted by the up-conversion material (12) when the up-conversion material (12) is irradiated by designated wavelengths of infrared electromagnetic radiation.

Abstract: Ultrasound induced by RF irradiation within FDA exposure limits is produced with sufficient signal-to-noise ratio to allow acquisition of sub-millimeter resolution images within practical time frames.

Abstract: An apparatus having a coil of wire, energized by a repetitively pulsed radio frequency (RF) power source to provide electromagnetic fields to a region within a body. A scanning, directional hydrophone acoustically connected to the body, samples ultrasonic radiation generated by the RF fields at the RF frequency or twice the RF frequency induced from conductive spots. Signals from the hydrophone are analyzed with regard to their time of arrival relative to the RF pulses and with respect to their direction of arrival. These collected data are recorded and displayed as images of the spots within the region.

Abstract: A method of two interferometric configurations to measure bending of an extended element. The measurement arm of each configuration is a long optical fiber. A first interferometric configuration has a segment of its measurement arm attached to one side of the element. The second interferometric configuration has a segment of its measurement arm attached to one side of the element and another segment of its measurement arm attached to an opposing side of the element. The two configurations are used to obtain two sets of interference fringe measurement values. If one set is subtracted from the other, the result is intensity differential values that indicate only the effects of bending and not of temperature or pressure. Variations of the method can be used for irregularly shaped elements.

Abstract: A waveguide designed to minimize bend-induced losses. The waveguide has three regions of varying indices of refraction. The indices of refraction are chosen so that the field is a trigonometric function in the core region, evanescent in the intermediate region, and trigonometric again in the outer region. The widths of each region are calculated to further reduce losses.

Abstract: A fiber optic interferometric sensor (150) having constantly high sensitivity by use of two lasers (152, 154) that simultaneously output at first and second wavelengths. By judicious choice of the wavelengths, the optical path length difference between the two interferometer paths (164, 166) can be kept near the maximum slope of the interference fringes for one or the other of the wavelengths. The output from the interferometer (160) is divided between first and second detector arms (170, 130). A filter (172) in the first detector arm passes the first wavelength and rejects the second. A filter (182) in the second detector arm passes the second wavelength and rejects the first. A first detector (174) at the output of the first detector arm reads the interference pattern at the first wavelength. A second detector arm reads the interference pattern at the second wavelength.

Abstract: An array of acoustic signal sources and sensors are positioned in a fluid. Acoustic signals propagated through the medium are subjected to phase differences as they pass through fluid currents. An eikonal description of the acoustic waves propagating through the fluid medium is used to derive the fluid currents. Fluid currents are measured in a multiplicity of acoustic paths extending from the acoustic sources to the sensors, using acoustic phase tomography.

Abstract: An improved image transmission system which includes an elongate optical waveguide 15 having an input aperture 17 and an output aperture 19. Optical apparatus 11, 13 is provided for injecting a transform of an image into the waveguide. In a specific implementation, the Fourier transform of the image is injected at the input aperture 17. The output image is transformed as well to provide the desired image. When the Fourier components of the image are transmitted, each component propagates at a different velocity. However, the magnitude of the components are preserved and used to reconstruct the image at the output of the waveguide. This allows for the transmission of optical images without digitization with a single, inexpensive waveguide.

Abstract: A system for optically generating expansion coefficients for an image processing function. The invention (10) includes a first optical element (18) for providing a transform of an image provided at a first image plane (16). A second optical arrangement (20) provides a product of the transform of the image and a transform of a convolving function. This product is transformed by a lens (22) to provide an image intensity distribution representative of expansion coefficients resulting from a convolution of the image by the convolving function. In a specific implementation, the convolving function is a wavelet and the intensity distribution is detected to provide the expansion coefficients.

Abstract: Selective emissivity coatings are disclosed for temperature reduction of enclosures such as vehicles and building structures. The coating includes a selective emissivity material such as silicon-oxy-nitride having a desired thermal emissivity function which is high in the 8-13 micron wavelength region, and low elsewhere except in the visible wavelength region. The material provides a mechanism for radiative cooling of the enclosure by converting the blackbody radiation of the enclosure, which would be reflected by the earth's atmosphere, into far infrared radiation which is transmitted by the atmosphere. According to another aspect of the invention, the coating further comprises a semimetal which is reflective of radiation in the near infrared region, thereby reducing the solar heat load on the enclosure. One suitable semimetal is LaB.sub.6. The coating may be applied to the exterior surface of vehicle and building windows, or to the exterior, non-window surfaces of building structures.

Abstract: An apparatus for measuring the conductivity of a fluid is disclosed. The invention 10 provides both a contact and non-contact monitoring of fluid conductivity by measuring the A.C. dielectric properties of the fluid. The invention 10 transmits an electromagnetic wave into the fluid 22 and analyzes the transmitted and reflected waves providing an indication of the conductivity of the fluid 22. The invention 10 is versatile in that it allows for the fluid to be in the form of a spray. In a specific illustrative implementation, a novel nozzle is provided to monitor the conductivity of paint spray 22 as it passes therethrough.

Abstract: An optical fiber disposed to partially internally reflect optical energy passing therethrough is disclosed herein. The optical fiber 10 of the present invention includes an internal partial mirror disposed to partially transmit and to partially reflect optical energy incident thereon. The internal mirror is effectively realized at an interface I of first and second fiber segments 14 and 18. The first fiber segment 14 includes a first core region 22 which circumscribes a longitudinal axis X. The first core region 22 is of a first cross-sectional area perpendicular to the longitudinal axis X. The inventive fiber 10 further includes a second fiber segment 18 in optical communication with the first fiber segment 14. The second fiber segment 18 includes a second core region 24 which circumscribes the longitudinal axis X, wherein the second core region 24 is of a second cross-sectional area perpendicular thereto.

Abstract: A sensitive towed optical fiber sensor array 50, wherein the fiber sensors (60A-60N) are connected in parallel, and the optical fiber cable (34) is paid out from the towing ship at a velocity about equal to but opposite to the velocity of the towing ship. The fiber sensors (60A-60N) are immune to electromagnetic interference, and the output of the sensors can be isolated readily to the parallel hookup of the sensors. Turbulence and acceleration noise is greatly reduced due to the manner in which the fiber cable (34) is paid out, and crosstalk between sensors is eliminated.

Abstract: A nondestructive noninvasive device and method for testing printed circuit boards (PCBs) through the utilization of a liquid crystal material which visually images the electric fields of the PCBs. Circuit faults resulting in a change of current flow in a PCB produce recognizable changes in observed electric fields. The present invention may be used in a stand-alone mode or as a supplement to other testing techniques.

Abstract: An optical fiber evanescent wave fuel sensor, employing a light source with a wavelength selected to be at the strong infrared absorption lines of the fuel, typically hydrocarbons. The amount of light leaking from the optical fiber is an exponential function of the length of the fiber in the liquid, and is independent of the relative indices of refraction of the fuel and fiber cladding material.

Abstract: A nondestructive method and apparatus is disclosed for determining the thickness and composition of a zinc phosphate layer applied to a metal surface, such as sheet metal on an automotive assembly line. The phosphate layer is irradiated with infrared light which is at least partially transmitted through the phosphate layer. Reflections from the upper and lower surfaces of the phosphate layer return a total reflected intensity which is a function of the optical parameters of the phosphate components and the ratio of the components corresponding to the optical parameters. In the event, for example, that a phosphate layer includes two zinc phosphate components, the measure of reflected intensity at two separate wavelengths will be different inasmuch as the optical properties of the zinc phosphate components is also a function of frequency.