1189 results about "Spectral analysis" patented technology

A multi-stage speech recognition system includes an audio transducer that detects a speech signal, and a sampling circuit that converts the transducer output into a digital speech signal. A spectral analysis circuit identifies a portion of the speech signal corresponding to a first class and a second class. The system includes memory storage or a database having a first and a second vocabulary list. A recognition circuit recognizes the first class based on the first vocabulary list to obtain a first recognition result. A matching circuit restricts a vocabulary list based on the first recognition result, and a recognizing circuit recognizes the second class based on the restricted vocabulary list, to obtain a second recognition result.

A medical instrument system comprises an elongate instrument body; an optical fiber coupled in a constrained manner to the elongate instrument body, the optical fiber including one or more Bragg gratings; a detector operably coupled to a proximal end of the optical fiber and configured to detect respective light signals reflected by the one or more Bragg gratings; and a controller operatively coupled to the detector, wherein the controller is configured to determine a geometric configuration of at least a portion of the elongate instrument body based on a spectral analysis of the detected reflected portions of the light signals.

A sample element includes first and second substantially parallel faces separated by an intermediate member. The parallel faces and the intermediate member at least partially define a sample chamber configured to hold a volume of fluid. The sample element further includes an optical path extending through the parallel faces and the intermediate member, such that electromagnetic radiation can propagate through the sample chamber. The sample element further includes an identifying compound disposed within or on at least one of the parallel faces. The identifying compound has at least one indexed optical absorbance feature, such that spectral analysis of electromagnetic radiation propagated through the sample chamber yields the indexed optical absorbance feature. Detection of the indexed optical absorbance feature in electromagnetic radiation propagated through the sample chamber indicates to an analyte detection system whether the sample element is configured for use with the analyte detection system.

The present invention provides a diagnostic tool for detection of Cheyne-Stokes Respiration (CSR). This invention also provides a method for development of the diagnostic tool. The method comprises the steps of performing overnight oximetry recordings in patients suspected of sleep disordered breathing. Spectral analysis is performed on the oximetry recordings to obtain a set of parameters which can be used in the construction of a classification tree and a trained neural network. The diagnostic tools of the present invention can be used for classification of a patient as having CSR or obstructive sleep apnea.

A minimally invasive, implantable heart sound and ECG monitor and associated method for deriving blood pressure from heart sound data. The device is equipped with an acoustical sensor for detecting first and second heart sounds which are sampled and stored during sensing windows following R-wave and T-wave detections, respectively. ECG and heart sound data are stored in a continuous, looping memory, and segments of data are stored in long-term memory upon an automatic or manual data storage triggering event. Estimated blood pressure is calculated based on custom spectral analysis and processing of the first and second heart sounds. A calibration method includes measuring a patient's blood pressure using a standard clinical method and performing regression analysis on multiple spectral variables to identify a set of best fit weighted equations for predicting blood pressure. Concurrent ECG and estimated blood pressure may be displayed for review by a physician.

A telephone call reception system which infers mental and/or physiological states of callers. Two types of analysis are available, and both types may be used upon the telephone calls. In one type, speech recognition is performed upon the call to generate a text file. Key words are sought in the text file. In the second type, the electrical signal itself is processed, as by a spectral analysis. Information obtained by the two analyses is used to predict the mental or physiological state of the caller.

A handheld ultrasound instrument is disclosed having enhanced diagnostic modes including pulse/continuous wave Doppler, time-motion analysis, spectral analysis and tissue harmonic imaging. An external electrocardiograph (ECG) recording unit is also disclosed. The ECG unit is adaptable to be used with the handheld ultrasound instrument to provide for ECG monitoring while performing an ultrasound scan in B-mode, Doppler, color Doppler, M-mode, and CW/PW mode. The enhanced handheld ultrasound instrument further includes a security mechanism allowing any combination of the diagnostic modes to be enabled by the manufacturer, and later to enable or disable any one or group of the diagnostic modes. The invention also discloses a method for a manufacturer to maintain a database of handheld ultrasound instrument capabilities after the instruments enter the stream of commerce.

A catheter based method and apparatus for reflectance generated absorption spectral analysis of chronic inflammatory vascular conditions such as seen with atherosclerotic plaque within a blood vessel or other body cavity or compartment. The use of a bright mid range infrared light (mid-IR) source yields detectable reflected optical signals that may be sampled from an area smaller or larger than the typical diameter of a mammalian cell. The mid-IR light is delivered at selected mid-infrared wavenumbers. Using the apparatus and methods, the reflectance spectra and reflectance generated absorption spectra of a target tissue can be compared to reference spectra to identify and distinguish normal epithelium from tissue containing physiological markers indicative of vascular disease or other inflammatory conditions.

Systems and methods for using wireless radios for spectral analysis. Systems and methods include using wireless radios that are included in wireless devices communicating on the wireless network to perform a spectral scan of frequencies on a wireless network.

Systems and methods to assist in locating the focus of an atrial fibrillation include the association of atrial fibrillation cycle length values and statistics relating thereto with temporal locations on an electrogram of a given electrode, and/or the coordination of electrode locations with respective the spectral analyses of electrogram signals and further parameters and statistics relating thereto. Ablation therapy can proceed under guidance of such information.

A method and computer program product comprising an algorithm adapted to execute a method of identifying the spatial coordinates of a sustaining source of fibrillatory activity in a heart by computing a set of point-dependent dominant frequencies and a set of point-dependent regularity indices for a set of products of point-dependent unipolar discrete power spectra and point-dependent bipolar discrete power spectra, derived by spectral analyses of corresponding unipolar and bipolar cardiac depolarization signals simultaneously acquired from a set of points of the heart. A maximum dominant frequency is selected whose associated coordinates identify the point of the sustaining source of fibrillatory activity. The magnitude of the regularity index is interpreted to verify the identification of the spatial coordinates of the sustaining source of fibrillatory activity. When indicated, surgical intervention is directed to the spatial coordinates of the sustaining source of fibrillatory activity.

Methods and systems for automated identification of celebrity face images are provided that generate a name list of prominent celebrities, obtain a set of images and corresponding feature vectors for each name, detect faces within the set of images, and remove non-face images. An analysis of the images is performed using an intra-model analysis, an inter-model analysis, and a spectral analysis to return highly accurate biometric models for each of the individuals present in the name list. Recognition is then performed based on precision and recall to identify the face images as belonging to a celebrity or indicate that the face is unknown.

A method for determining a degree of acoustic non-linearity of an earth formation from seismic signals transmitted into the formation from within one wellbore and received from the formation in another wellbore. The seismic signals include two selected discrete frequencies. The method includes spectrally analyzing the received signals, determining from the spectral analysis the presence of a frequency representing a sum of the two selected frequencies, and determining a relative amplitude of the sum frequency with respect to the amplitudes of the two selected discrete frequencies. In a particular embodiment, the method includes determining the presence of a frequency in the spectrally analyzed signals representing the difference between the selected discrete frequencies, and determining the presence of harmonic multiples of one of the two selected discrete frequencies.

A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.

The present invention is directed generally toward the field of spectral analysis and, more particularly, toward an improved method of identifying unknown components of a mixture from a set of spectra collected from the mixture using a spectral library including potential candidates. For example, the present method is directed to identifying components of a mixture by the steps which comprise obtaining a set of spectral data for the mixture that defines a mixture data space; ranking a plurality of library spectra of known elements according to their angle of projection into the mixture data space; calculating a corrected correlation coefficient for each combination of the top y ranked library spectra; and selecting the combination having the highest corrected correlation coefficient, wherein the known elements of the selected combination are identified as the components of the mixture.

Apparatus and methods are provided for the imaging of structures in deep tissue within biological specimens, using spectral imaging to provide highly sensitive detection. By acquiring data that provides a plurality of images of the sample with different spectral weightings, and subsequent spectral analysis, light emission from a target compound is separated from autofluorescence in the sample. With the autofluorescence reduced or eliminated, an improved measurement of the target compound is obtained.

The system and method for spectral analysis uses a set of spectral data. The spectral data is arranged according to a second dimension, such as time, temperature, position, or other condition. The arranged spectral data is used in a signal separation process, such as an independent component analysis (ICA), which generates independent signals. The independent signals are then used for identifying or quantifying a target component.

A method is disclosed for determining movement mode in a drill string. The method includes measuring lateral acceleration of the drill string, determining lateral position of the drill string from the acceleration measurements, and determining mode from the position with respect to time. Also disclosed is a method including measuring drill string acceleration along at least one direction, spectrally analyzing the acceleration, and determining existence of a particular mode from the spectral analysis. Also disclosed is a method for determining destructive torque on a BHA including measuring angular acceleration at at least one location along the BHA, and comparing the acceleration to a selected threshold. The threshold relates to a moment of inertia of components of the BHA and a maximum torque applicable to threaded connections between BHA components. A warning is generated when acceleration exceeds the threshold.

A linearizer reduces nonlinear intermodulation distortion in radio frequency and microwave systems by first directly generating in-phase and quadrature nonlinear intermodulation products of the system input. Controllable amounts of each phase are then added back into the system such that the vector sum of nonlinear intermodulation products at the output is reduced or eliminated by destructive interference, while the fundamentals are substantially unaffected. The quadrature distorted signals are generated with two lightly-biased and thus overdriven differential pairs having gain-determining degeneration impedances that are in quadrature with each other. The amount of each quadrature phase summed to the output is controlled with electronically tunable four-quadrant variable attenuators. The quadrature phasing enables rapidly convergent tuning to minimize distortion using conventional scalar spectral analysis. The advantages of a linearizer using rectangular vector coordinate system are significant.

A CARS system and method for probing a Raman signature of a sample are described. A short femtosecond pulse from one or more lasers is split into two pulses, a stimulus pulse and a probe pulse, whereby the probe pulse is time-delayed with respect to the stimulus pulse. Both pulses can be phase- and polarization-modulated. The stimulus pulse excites a vibronic level in the sample and the probe pulse probes molecular Raman transitions in the sample. A difference in the signals with and without excitation can be used to determine on which molecule a bond is most likely located. This will allow an accurate and sensitive determination of the presence of specific molecules in the sample. The system and method can be used to analyze biological samples and to discriminate between molecules having overlapping Raman signatures.

A system and method for detection of impurities in gases comprising a Fourier transform infrared spectrometer and computation devices for system control, spectral analysis, and chemometrics.

Apparatus and methods for determining, in-vivo, characteristics of sub-surface tissues or fluids in the human or animal body are disclosed. Incident radiation is supplied at one or more entry regions on a surface, and light is collected from one or more collection regions spaced from the entry regions. Raman features are detected in the collected light and depth related information derived therefrom.

A method and system for determination and mapping the quantity of chromophores having a distinct spectrum attached to moving objects in an spectrally rich environment that may include multiple chromophores attached to stationary objects. An area of inters is imaged at different times and different wavelengths, and the spectral properties of the or more chromophores attached to the moving objects are separated from the stationary spectral properties of the background, followed by spectral analysis of the moving objects to determine their quantity. Application to the retinal vasculature is illustrated, showing the imaging, analyzing and quantifying of the oxygen saturation of retinal blood, resolved for the different vascular compartments—capillaries, arterioles, venules, arteries, and veins. Changes in the structure of the vascular environment are also determined, whether growth of new vessels or the elimination of existing ones, by the generation of path maps based on analysis of differential images taken at a single wavelength of the moving components in the blood flow.

Spectrogram extraction from DNA sequence has been known since 2001. A DNA spectrogram is generated by applying Fourier transform to convert a symbolic DNA sequence consisting of letters A, T, C, G into a visual representation that highlights periodicities of co-occurrence of DNA patterns. Given a DNA sequence or whole genomes, with this method it is easy to generate a large number of spectrogram images. However, the difficult part is to elucidate where are the repetitive patterns and to associate a biological and clinical meaning to them. The present disclosure provides systems and methods that facilitate the location and/or identification of repetitive DNA patterns, such as CpG islands, Alu repeats, tandem repeats and various types of satellite repeats. These repetitive elements can be found within a chromosome, within a genome or across genomes of various species. The disclosed systems and methods apply image processing operators to find prominent features in the vertical and horizontal direction of the DNA spectrograms. Systems and methods for fast, full scale analysis of the derived images using supervised machine learning methods are also disclosed. The disclosed systems and methods for detecting and/or classifying repetitive DNA patterns include: (a) comparative histogram method, (b) feature selection and classification using support vector machines and genetic algorithms, and (c) generation of spectrovideo from a plurality of spectral images.

A method and visualization apparatus for spectral analysis of time-and-space varying signals enables high resolution investigation of 3D seismic data for the exploration of oil and gas. The method extrapolates multi-resolution short windows into an average long window then computes its FFT. Extrapolation uses the continuity relationship between data inside and outside of short windows. Applications of the method are illustrated with graphical screen 3D volume displays of amplitude spectra, dip and azimuth, curvature and faults (figure below). Aside from high resolution these displays improve the productivity of a seismic interpreter.

A system for temporal and spectral resolved detection of photon emission from an integrated circuit is disclosed. A DUT is stimulated by a conventional ATE, so that its active devices emit light. The signal from the ATE is also sent to the system's computer as a synchronization signal. The light emitted from the switching devices is passed through a wavelength filter. Selected bands of wavelengths are then passed to respective detector(s) and the detector(s) response with respect to the time correlated ATE stimulus is studied.

The invention is a method and apparatus capable of detecting constituents of a gas at extremely low concentrations comprising providing a medium that is absorbent of at least a first particular gas under a first environmental condition and desorbent of the particular gas under a second environmental condition, exposing the medium to a sample gas for a first period of time under the first environmental condition, during a second period of time after the first period of time, exposing the medium to the second environmental condition to cause the medium to desorb gas into an optical cavity of a cavity ring down spectrometer and introducing electromagnetic radiation into the cavity, during a third period of time after the second period of time, ceasing introduction of the electromagnetic radiation into the cavity and detecting the decay of the electromagnetic radiation in the cavity, and analyzing the decay of the light in the cavity to obtain a spectral analysis of the sample gas.

A system and method for acoustic detection of coronary artery disease (CAD) are provided. The system includes a transducer for acoustically detecting heart signals of a patient and a computer system which executes detection software for processing the detected heart signals to identify the presence of CAD from the heart signals. The software allows for the automatic definition of a diastolic “window” of the acoustic signal for analysis, and automatically edits the sampled acoustic signal to eliminate unwanted artifacts and/or noise in the acoustic signal. The edited signal is then processed by a plurality of signal processing algorithms, including spectral analysis algorithms, time-frequency algorithms, global feature algorithms, kurtosis algorithms, mutual information algorithms, negenthropy algorithms, and principal component analysis algorithms, to generate a disease vector. The disease vector is then classified to determine whether CAD is present in the patient. Classification can be accomplished using linear discriminant analysis or a support vector machine.

The invention provides an abnormal engine sound fault on-line diagnostic system and diagnostic method. The diagnostic system comprises a sound signal sensor, a sound signal collecting and storing module and an analysis and diagnosis module. The analysis and diagnosis module comprises a spectral analysis and diagnosis module, a wavelet analysis and diagnosis module and a psychological acoustics analysis and diagnosis module, wherein the spectral analysis and diagnosis module is used for obtaining frequency spectrum parameters through the spectral analysis, the wavelet analysis and diagnosis module is used for obtaining energy parameters through the wavelet analysis, and the psychological acoustics analysis and diagnosis module is used for obtaining psychological acoustics parameters through the psychological acoustics analysis. The spectral analysis and diagnosis module, the wavelet analysis and diagnosis module and the psychological acoustics analysis and diagnosis module are used for extracting the frequency spectrum parameters, the energy parameters and the psychological acoustics parameters respectively to show abnormal sound fault characteristics. The abnormal engine sound fault on-line diagnostic system replaces manual work to carry out on-line diagnostic working on the abnormal engine sound fault, the diagnostic accuracy and consistency are high, the abnormal sound fault diagnosis requirements for real-time performance, fastness and accuracy of an engine production line can be met, and the working efficiency of an engine detection line is improved.

The invention is directed to a hyperspectral/multispectral system referred to as the OxyVu-1 system. The hyperspectral imaging technology performs spectral analysis at each point in a two-dimensional scanned area producing an image displaying information derived from the analysis. For the OxyVu-1 system, the spectral analytical methods determined in superficial tissues approximate values of oxygen saturation (HT-Sat), oxyhemoglobin levels (HT-oxy), and deoxyhemoglobin levels (HT-deoxy). The OxyVu-1 system displays the tissue oxygenation in a two-dimensional, color-coded image.

The system contains a system console, a cart, system electronics, CPU, monitor, keyboard, pointing device and printer. The hyperspectral instrument head with support arm contains broadband illuminator, camera and spectral filter for collecting hyperspectral imaging cube. The single use OxyVu Check Pads and Targets are used to perform an instrument check prior to patient measurements. The OxyVu Target is placed within the intended field of view and is used as a fiduciary mark for image registration and for focusing.