32results about How to "Maximize signal to noise" patented technology

Methods and systems are disclosed for detecting overheating in an optical device before harmful consequences, such as severe local heating, can result. In one embodiment of the invention, a blackbody emitter is disposed in close proximity to a therapeutic optical fiber to absorb therapeutic radiation at a fault and re-emit blackbody (infrared) radiation. The emitter can be coupled to the fiber but, during normal operation, lies outside the optical path between the output of the laser radiation and the site of treatment. Systems and catheters incorporating such emitters are also described for effective monitoring of the laser power transmitted along the optical fiber within the phototherapy device.

Gas focusing flow cytometers are fabricatable employing simple and inexpensive manufacturing techniques. When such cytometers or conventional cytometers are combined with fiber optical light paths and laser diode and semiconductor photodetectors, light weight and handheld, optionally disposable devices which maintain high performance are possible.

A subscriber unit for use in a multiple access spread-spectrum communication system includes a spread spectrum radio interface, responsive to a rate function signal from a base station, and first and second despreaders. The base station assigns the rate function spread-spectrum message channels and the first despreader recovers and modifies an information signal one of the spread spectrum message channels. The information channel mode is then modified for processing by the second despreader, with the second despreader supporting a different information signal rate. The subscriber unit has a capability of communicating with a dynamically changing a transmission rate of an information signal which includes multiple spread spectrum message channels. The system includes a closed loop power control system for maintaining a minimum system transmit power level for a radio carrier station and the subscriber units, and system capacity management for maintaining a maximum number of active subscriber units for improved system performance.

OCT apparatus includes an interferometer, having an input beam splitter and a 50 / 50 output splitter. The splitting ratio of the input splitter may be optimized depending on the source power of light source and on the mismatch of the balanced receiver. The input splitter is a plate beam-splitter to minimize the stray reflected light in the interferometer and allow sequential operation of the apparatus in the OCT or in the confocal regime. The switching between the two regimes may be at will, or synchronous with the en-face scanning which results in quasi-simultaneous OCT / confocal imaging or in alternatives frames, confocal and OCT. By using polarization sensitive elements, two channels are provided in each regime, OCT and confocal. The two confocal polarization sensitive channels may allow adjustments of compensators prior to OCT measurements or OCT imaging.

Gas focusing flow cytometers are fabricatable employing simple and inexpensive manufacturing techniques. When such cytometers or conventional cytometers are combined with fiber optical light paths and laser diode and semiconductor photodetectors, light weight and handheld, optionally disposable devices which maintain high performance are possible.

A speech encoder comprises an encoding element for encoding a noise reduced speech signal, and a noise suppression element that takes a noisy speech signal and generates the noise reduced speech signal by maximizing the signal to noise ratio (SNR) of the noisy speech signal without suppressing the voiced speech components of the noisy speech signal. The noise suppression element may use harmonic modeling techniques that maximize the SNR in each sub-band of the noisy speech signal by reconstructing the voiced speech components of the noisy voiced speech signal emphasizing harmonic frequencies within each sub-band. The SNR is further maximized by eliminating noise components between signal peaks at the harmonic frequencies, and eliminating noise at signal peaks at the harmonic frequencies by smoothing harmonic parameters generated by the reconstruction of the voiced speech components of the noisy speech signal.

A method and for optimizing bit rate throughput in a digital communication system is provided. The method includes establishing a relationship between signal to noise ratio and plural symbol rates for a particular constellation size. The method also includes determining noise power spectral density (N(f)), wherein N(f) is determined during a silent period of line probing; determining Xk(f), wherein Xk(f) is determined by turning on a remote station transmit signal, after N(f) has been measured and determining residual echo Ek(f), wherein Ek(f) is determined by turning on a central station echo canceller.

Disclosed are methods and apparatus for inspecting a semiconductor sample. This system comprises an illumination optics subsystem for generating and directing an incident beam towards a defect on a surface of a wafer. The illumination optics subsystem includes a light source for generating the incident beam and one or more polarization components for adjusting a ratio and / or a phase difference for the incident beam's electric field components. The system further includes a collection optics subsystem for collecting scattered light from the defect and / or surface in response to the incident beam, and the collection optics subsystem comprises an adjustable aperture at the pupil plane, followed by a rotatable waveplate for adjusting a phase difference of electric field components of the collected scattered light, followed by a rotatable analyzer. The system also includes a controller that is configured for (i) selecting a polarization of the incident beam, (ii) obtaining a defect scattering map, (iii) obtaining a surface scattering map, and (iv) determining a configuration of the one or more polarization components, aperture mask, and rotatable ¼ waveplate, and analyzer based on analysis of the defect and surface scattering map so as to maximize a defect signal to noise ratio,

An acquisition and averaging circuit is provided in which, during a sampling phase capacitors in sample blocks 4 and 6 are sequentially connected to the input signal to sample it and are then isolated so as to hold the sample. The capacitors are then connected to a combining / averaging arrangement such that an average of the sample values is formed.

System and method for borehole compensation. The method includes simultaneously transmitting at least two modulated signals from one or more transmitters; receiving the at least two modulated signals by at least one receiver; and processing the received at least two modulated signals to determine a phase difference and an amplitude attenuation of the transmitted modulated signals, the processing providing borehole compensated data.

A system and method for detecting a functional signal in retinal images. An optical imaging device comprises a stimulation light source, an interrogating light source, and a detector. The retina is stimulated by the stimulation light source. The retina is then illuminated by an interrogation light, and the reflected intensity from the retina is measured at an interrogating spectral band that indicates the state of hemoglobin saturation before and after visual stimulation. The optical changes that result from retinal neuronal activity are captured by the detector. The signal representing the state of hemoglobin saturation before and after visual stimulation is isolated. In an embodiment of the present invention, this signal is isolated using principle components analysis (PCA). In another embodiment of the present invention, blind source separation (BSS) and independent component analysis (ICA) algorithms such as extended spatial decorrelation and fast-ICA are used to isolate the functional signal from the retinal videos.

A method for acquiring a digital image of an agglutination result comprising performing an agglutination assay on a reaction substrate having a set of dimensions and characteristics which permit a pattern of agglutination in a result of said assay. The image of the result is developed. The image has a colored background which maximizes a signal to noise ratio. Further, the image has been passed through a filter that complements an action of the colored background and enhances the agglutinates in the image while additionally increasing the signal to noise ratio.

An acquisition and averaging circuit is provided in which, during a sampling phase capacitors in sample blocks 4 and 6 are sequentially connected to the input signal to sample it and are then isolated so as to hold the sample. The capacitors are then connected to a combining / averaging arrangement such that an average of the sample values is formed.

A method and apparatus for channel estimation in a spread spectrum receiver include processing that begins by despreading a received spread spectrum complex baseband sample utilizing a pseudorandom spreading sequence to produce a despread baseband symbol. The processing continues by filtering the despread baseband symbol to attenuate adverse channel effects based on a channel response estimate to produce a filtered despread baseband symbol. The processing then continues by decoding the filtered despread baseband symbol to produce recaptured data. The processing continues by modulating the recaptured data to produce a remodulated symbol. The processing then continues by producing a reconstructed spread spectrum complex baseband sample from the remodulated symbol based on the pseudorandom spreading sequence. The processing then continues by generating the channel response estimate such that a convolution of the channel response estimate with the reconstructed spread spectrum complex baseband sample substantially emulates the received spread spectrum complex baseband sample.

System and method for borehole compensation. The method includes simultaneously transmitting at least two modulated signals from one or more transmitters; receiving the at least two modulated signals by at least one receiver; and processing the received at least two modulated signals to determine a phase difference and an amplitude attenuation of the transmitted modulated signals, the processing providing borehole compensated data.

OCT apparatus includes an interferometer, having an input beam splitter and a 50 / 50 output splitter. The splitting ratio of the input splitter may be optimized depending on the source power of light source and on the mismatch of the balanced receiver. The input splitter is a plate beam-splitter to minimize the stray reflected light in the interferometer and allow sequential operation of the apparatus in the OCT or in the confocal regime. The switching between the two regimes may be at will, or synchronous with the en-face scanning which results in quasi-simultaneous OCT / confocal imaging or in alternatives frames, confocal and OCT. By using polarization sensitive elements, two channels are provided in each regime, OCT and confocal. The two confocal polarization sensitive channels may allow adjustments of compensators prior to OCT measurements or OCT imaging.

A system and method for detecting a functional signal in retinal images. An optical imaging device comprises a stimulation light source, an interrogating light source, and a detector. The retina is stimulated by the stimulation light source. The retina is then illuminated by an interrogation light, and the reflected intensity from the retina is measured at an interrogating spectral band that indicates the state of hemoglobin saturation before and after visual stimulation. The optical changes that result from retinal neuronal activity are captured by the detector. The signal representing the state of hemoglobin saturation before and after visual stimulation is isolated. In an embodiment of the present invention, this signal is isolated using principle components analysis (PCA). In another embodiment of the present invention, blind source separation (BSS) and independent component analysis (ICA) algorithms such as extended spatial decorrelation and fast-ICA are used to isolate the functional signal from the retinal videos.

A periodic broadband signal can be used to determine the S21 measurement for a channel by stimulating the channel across a spectrum of interest. The channel response to such broadband signal can be measured from undersampled data captured at the receiver. The Fourier transform of the broadband signal as received, divided by the Fourier transform of broadband signal as transmitted, constitutes the S21. A physically contiguous IC can integrate both a receiver circuit, at which S21 is to be measured, along with an undersampler for sampling the received broadband signal. To maximize signal to noise, a pattern for the broadband signal can be selected to maximize the minimum power across the spectrum of interest. A pattern generator for the broadband signal can be integrated on the same physically contiguous IC with a multiplexer that can select either the pattern generator, or a typical source of data, for transmission into the channel.

A method and apparatus for mitigating for inter-symbol interference in a communication system using a multi-rate adaptive decision feedback equalizer (DFE) with a feedforward filter which is a combination of a first feedforward filter (FF1) that performs match filtering and a second feedforward filter (FF2) which runs at a lower sampling rate than first feedforward filter (FF1), thereby, reducing the total the number of computation done at the receiver, and removes ISI and white noise.The present invention also employs a method and apparatus where the initial training is done separately for the first feedforward filter (FF1) and the second feedforward filter (FF2). An approximate solution of the optimal receiver has the first feedforward filter (FF1) maximize the output signal to noise ratio (SNR) which is used to train first feedforward filter (FF1).

A gesture recognition apparatus includes a sensor unit configured to be worn by a user on a user's body part. The sensor unit includes one or more sensors, a processor unit, the processor unit and the sensor unit are arranged in communication with each other, the processor unit receiving acoustic data from the one or more sensors, wherein the acoustic data corresponds to a gesture performed by a user, and the processor unit is configured to process the acoustic data received from the one or more sensors to determine a gesture performed by the user.

The present invention includes a semiconductor epitaxial structure optimized for photoconductive free space terahertz generation and detection; and amplifier circuits for photoconductively sampled terahertz detection which may employ the optimized epitaxial structures.

A common path interferometer is disclosed. The interferometer is arranged to divide an input beam into first and second beam portions directed in opposite directions around a cyclic path to form an interference pattern at a detector. The cyclic path is defined by at least two mirror regions curved in the plane of the cyclic path, such that the interference pattern represents path difference variations between the first and second beam portions. The interferometer further includes an input optic arranged in the beam path before division of the input beam into the beam portions. The input optic is configured to provide convergence to reduce the extent transversely to the plane of the cyclic path of the interference pattern at the detector. The beam and beam portions have different convergence requirements in the plane of, and transverse to the plane of, the cyclic path, which are addressed separately by the mirror regions and the input optic.

A method for analyzing a digital image containing the result of an agglutination assay to generate a quantitative result value representative of the degree of agglutination of the sample is provided. The method for analyzing the digital image includes: applying a filter to extract a component of the image or portion of a spectrum where a signal to noise ratio between agglutinated and background is maximized; extracting a set of features that characterize the agglutination pattern, obtaining a quantification function which maps measured features to the actual concentration of the sample and computing a quantitative result for each sample in the assay.

The invention relates to a hydrophone housing. The housing comprises an outer casing with an exterior shape being in close contact with sediment when buried therein and having a deflectable wall part. Solid material partly fills the casing to define an outer chamber behind the deflectable wall part, a cavity shaped so that an inner chamber is defined immediately surrounding a hydrophone sensing element held therein, and a first duct for liquid flow communication between the outer chamber and the cavity or an internal volume of the hydrophone sensing element. Thereby, a hydraulic coupling is provided so that an acoustic pressure causing small radial displacements of outer surface of the housing will, via liquid in the first duct, cause large radial displacements of the hydrophone sensitive element. The area of the deflectable wall part is much larger than the area of the sensitive element so that only small displacements of the housing are required to cause large displacements at the hydrophone sensing element.

Monitoring an optical signal utilizing optical heterodyne detection involves attenuating an input signal before the input signal is combined with a local oscillator signal. The input signal is attenuated in order improve the signal to noise ratio of the heterodyne signal that is generated when the input signal and the local oscillator signal are combined. The signal to noise ratio of the heterodyne signal improves with attenuation of the input signal, specifically in the case where the intensity noise from the input signal is the dominant noise source, because the heterodyne signal and the intensity noise of the input signal scale differently with attenuation of the input signal.

A system of the present invention is capable of detecting, imaging and measuring both neutrons and gamma rays. In some cases, the system has a plurality of parallel plates each containing a plurality of detectors. The plates comprise non-PSD organic scintillation detectors, scintillation detectors having pulse-shape discrimination (PSD) properties, and inorganic scintillation detectors. In some other cases, the system has a plurality of scintillation rods radially distributed about a central axis, and the scintillation rods comprise non-PSD organic scintillation detectors, scintillation detectors having pulse-shape discrimination (PSD) properties, and inorganic scintillation detectors. A first plate or rod and a second plate or rod are used in connection to detect, image and measure neutrons and / or gamma rays.

An x-ray microscopy method that obtains a classification of different particles by distinguishing between different material phases through a combination of image processing involving morphological edge enhancement and possibly resolved absorption contrast differences between the phases along with optional wavelet filtering.

A gesture recognition apparatus includes a sensor unit configured to be worn by a user on a user's body part. The sensor unit includes one or more sensors, a processor unit, the processor unit and the sensor unit are arranged in communication with each other, the processor unit receiving acoustic data from the one or more sensors, wherein the acoustic data corresponds to a gesture performed by a user, and the processor unit is configured to process the acoustic data received from the one or more sensors to determine a gesture performed by the user.

The invention relates to a hydrophone housing. The housing comprises an outer casing with an exterior shape being in close contact with sediment when buried therein and having a deflectable wall part. Solid material partly fills the casing to define an outer chamber behind the deflectable wall part, a cavity shaped so that an inner chamber is defined immediately surrounding a hydrophone sensing element held therein, and a first duct for liquid flow communication between the outer chamber and the cavity or an internal volume of the hydrophone sensing element. Thereby, a hydraulic coupling is provided so that an acoustic pressure causing small radial displacements of outer surface of the housing will, via liquid in the first duct, cause large radial displacements of the hydrophone sensitive element. The area of the deflectable wall part is much larger than the area of the sensitive element so that only small displacements of the housing are required to cause large displacements at the hydrophone sensing element.