Abstract: A method for efficient transmission of coefficients examines a coefficient list, presents the coefficients as binary floating point representation, and transmits the list of coefficients as a header having an exponent prefix, a fractional suffix, and each coefficient value as an exponent suffix and fractional prefix. A method for reception of coefficients receives a header including an exponent prefix, a fractional suffix, thereafter receiving each value as a sign bit, an exponent suffix and a fractional prefix, reconstituting an approximation of the original value, in sequence, as a sign bit, exponent prefix exponent suffix, fraction prefix, and fraction suffix, thereby greatly reducing the amount of information to be transmitted or received.

Abstract: An acoustic otoscope generates volume change excitations of either a trapezoidal or sinusoidal waveforms which are coupled into a sealed ear canal using a speculum tip. The change in volume results in a pressure change, for which a pressure measurement is taken during the volume change excitation interval. In one example, a trapezoidal time-domain volume change is presented, and a pressure measurement waveform is stored, the pressure measurement waveform thereafter examined to find a change of slope point in time, after which the pressure measurement waveform is scaled to be equal to the volume change waveform at that same point in time, a difference between scaled pressure measurement and volume excitation is formed, and examined for peak value prior to the earlier determined change in slope point in time.

Abstract: A method for efficient transmission of coefficients examines a coefficient list, presents the coefficients as binary floating point representation, and transmits the list of coefficients as a header having an exponent prefix, a fractional suffix, and each coefficient value as an exponent suffix and fractional prefix. A method for reception of coefficients receives a header including an exponent prefix, a fractional suffix, thereafter receiving each value as a sign bit, an exponent suffix and a fractional prefix, reconstituting an approximation of the original value, in sequence, as a sign bit, exponent prefix exponent suffix, fraction prefix, and fraction suffix, thereby greatly reducing the amount of information to be transmitted or received.

Abstract: An otoscope uses differential reflected response of optical energy at an absorption range and an adjacent wavelength range to determine the presence of water (where the wavelengths are water absorption wavelength and adjacent non-absorption excitation wavelengths). In another example of the invention, the otoscope utilizes OCT in combination with absorption and non-absorption range for bacteria and water.

Abstract: An otoscope uses differential reflected response of optical energy at an absorption range and an adjacent wavelength range to determine the presence of water (where the wavelengths are water absorption wavelength and adjacent non-absorption excitation wavelengths). In another example of the invention, the otoscope utilizes OCT in combination with absorption and non-absorption range for bacteria and water.

Abstract: An optical power combiner, or splitter, is formed from a first substrate and a second substrate, each substrate having a substantially planar joining surface, at least one substrate having a plurality of waveguide channels formed such as by etching, the plurality of waveguide channels coupled to a waveguide channel combiner having a plurality of waveguide channel apertures, the optical combiner having a single channel aperture on an opposite side from the plurality of waveguide channel apertures, the single channel aperture coupled to a single waveguide channel of zero or greater length, and to an edge opposite the plurality of waveguide channels.

Abstract: An OCT apparatus and method for characterization of a fluid adjacent to a tympanic membrane has a low coherence source which is coupled to a splitter which has a measurement path and a reference path. The reference path is temporally modulated for length, and the combined signals from the reference path and the measurement path are applied to a detector. The detector examines the width of the response and the time variation when an optional excitation source is applied to the tympanic membrane, the width of the response and the time variation forming a metric indicating the viscosity of a fluid adjacent to the tympanic membrane being measured.

Abstract: An ultrasound signal processor uses an excitation generator to cause displacement of a membrane or surface while a series of ultrasound pulses are applied to the membrane or surface. Phase differences between a transmitted signal and received signal are examined to determine the movement of the membrane or surface in response to the applied excitation. An examination of the phase response of the membrane or surface provides a determination as to whether the fluid type behind the membrane or surface is one of: no fluid, serum fluid, or purulent fluid.

Abstract: An OCT apparatus and method for characterization of a fluid adjacent to a tympanic membrane has a low coherence source which is coupled to a splitter which has a measurement path and a reference path. The reference path is temporally modulated for length, and the combined signals from the reference path and the measurement path are applied to a detector. The detector examines the width of the response and the time variation when an optional excitation source is applied to the tympanic membrane, the width of the response and the time variation forming a metric indicating the viscosity of a fluid adjacent to the tympanic membrane being measured.

Abstract: An ultrasound signal processor uses an excitation generator to cause displacement of a tympanic membrane while a series of ultrasound pulses are applied to the tympanic membrane. Phase differences between a transmitted signal and received signal are examined to determine the movement of the tympanic membrane in response to the applied excitation. An examination of the phase response of the tympanic membrane provides a determination as to whether the fluid type behind the tympanic membrane is one of: no fluid, serum fluid, or purulent fluid.

Abstract: A plurality of AWG filters with aliasing responses are selected such that the wavelength range of a fundamental response of the AWG filters results in the aliased range of AWG filters to be adjacent to a fundamental range of the AWG filters. A plurality of optical sources is provided sufficient to cover each fundamental wavelength range and each alias wavelength range of the AWG filters. When a single one of the optical sources is enabled, reflected optical energy from a series string of FBGs coupled to the optical source is applied to the plurality of AWG filters, and the AWG output in combination with the wavelength range of the optical source is used to discriminate reflected wavelength from the FBG sensors.

Abstract: A system for the generation and distribution a plurality of coherently phased system clocks comprises a local clock generator and a plurality of remote clock generators. Each clock generator has a local input and a plurality of remote inputs coupled to a plurality of phase detectors, a cost function coupled to each phase detector and producing a control output, and the control output coupled to a voltage controlled oscillator and producing a local clock output, which is distributed to each local and remote clock generator. The cost function comprises a linear or non-linear combination of phase error and offset. A clock selection circuit comprises a control input which changes a propagation time away from the coherently phased edges of the system clock, thereby selecting a system clock in a glitch-free manner.

Abstract: A transceiver for the transmission and reception of high speed optical signals contains a detuning structure which reduces the gain for quarter wave radiation of Electro Magnetic Radiation (EMI). A conductive housing couples light energy from a source or a detector to an external fiber having a metallic ferrule. The conductive housing also is referenced to the chassis enclosure of the transceiver thereby attenuating the quarter wave radiator.

Abstract: A pair of synchronized clock sources provides phase and frequency synchronous first and second clocks accompanied by first and second control signals to a clock selection circuit having a data selector comprising a first synchronizer and a second synchronizer which re-times the first and second control signals, and these re-timed outputs that are coupled to an asynchronous state machine. The asynchronous state machine changes state by logically operating on the re-timed control signals in conjunction with a state bit. This state bit is used to control the multiplexer, which achieves glitch-free switching between the first clock source and the second clock source.

Abstract: A generator of high frequency signals comprises a delay element and a switching element, whereby the delay element causes a delay of &pgr;/4 radians, and the switching element is switching to produce an output at the fundamental frequency, but with enriched even harmonic content. A filter selects the desired harmonic, and passes this on as an output. Additionally, a maximizing circuit may vary the phase of the delay element to maximize the output level of the generator.

Abstract: A plurality of power supplies are connected in parallel, each power supply isolated from the others using a non-linear isolation element such as a barrier diode. Feedback is furnished around the non-linear isolation element such that the voltage drop of the isolation element is reduced to be within the regulation range desired. The non-linear characteristic of the isolation element combined with feedback produces an output impedance which is low for high currents, and exponentially higher for low output currents for current sharing versus output offset voltage improvement.

Abstract: A four channel color display processor is described using separated cyan, magenta, yellow, and black color descriptions for color components. Each color component is then modified to enable use with a color monitor utilizing red, green, and blue phosphors. Colors are corrected prior to presentation to the color monitor, to eliminate the non-idealities of the color monitor, printing inks, or both. This invention allows the representation of colors shown in the color display to more accurately reflect the actual printed output.

Abstract: A cylindrical tube with closed ends contains an imaging fluid and a variety of imaging structures enclosed. Included is a slice thickness structure with a hole pattern in a chevron shape where the number of imaged holes determines the slice thickness. Slice planarity is determined by a number of contiguous disks with grooved patterns set at rotated angles with respect to each other. Geometric distortion and resolution are also measured by structures contained within the enclosure. Finally, the position of the first and last slices in a multiscan series is measured for accuracy by ramp wedges placed on the end caps of the enclosure. And lastly, air is entrapped in closed cell foam so there are no unconstrained bubbles migrating in the enclosure.