摘要:
A system and method for performing an ultrasound may include generating a set of continuous tone signals for injection into an object. A corresponding set of reflected tone signals in the frequency domain may be received The set of reflected tone signals may be converted from the frequency domain to the time domain to create a set of time domain signals. At least one region of interest may be identified from the set of time domain signals. A window may be defined around the identified region of interest in the set of time domain signals. The windowed time domain signals may be converted from the time domain to the frequency domain to create a set of windowed frequency domain signals. At least one characteristic parameter may be calculated from the set of windowed frequency domain signals. Information may be output based on the calculate at least one characteristic parameter.
摘要:
Apparatus and method for accurately quantifying the instantaneous radius curvature of a large plurality of points on the corneal surface is disclosed. A video image of the corneal surface accurately positioned at a predetermined point on the optic axis of measurement is obtained. The predetermined point is defined by intersecting low power laser beams. The video image is radially scanned from an original position at point defined by the intersection of the visual axis with corneal surface. Accurate measurements of the two-dimensional image radii of a plurality of illuminated mires reflective upon the corneal surface are made and corrected for camera distortions, quantization error and the different magnification occurring for different size corneas. The instrumentation is calibrated by using a plurality of mirror-like spheres of precisely known spherical radii.
摘要:
The voice print system of the present invention is a subword-based, text-dependent automatic speaker verification system that embodies the capability of user-selectable passwords with no constraints on the choice of vocabulary words or the language. Automatic blind speech segmentation allows speech to be segmented into subword units without any linguistic knowledge of the password. Subword modeling is performed using a multiple classifiers. The system also takes advantage of such concepts as multiple classifier fusion and data resampling to successfully boost the performance. Key word/key phrase spotting is used to optimally locate the password phrase. Numerous adaptation techniques increase the flexibility of the base system, and include: channel adaptation, fusion adaptation, model adaptation and threshold adaptation.
摘要:
A method and apparatus for improved mobile radio telecommunications employs the transmission of a pilot reference signal within the coherence band of the modulated carrier wave. The receiver in this system uses instantaneous phase estimation techniques of the pilot and carrier received waveforms to provide immunity from phase distortion introduced by the channel.
摘要:
A device for causing concentric circles of illuminated light to be reflected from the human cornea. The device includes a cylindrical surface which is open at both ends. At one end the eye looks into the cylinder of the device and at the other end a camera or observer can view the illuminated rings on the cornea. The cylinder is advantageously made of transparent plastic or glass having an opaque coating. A lamp box is affixed to an uncoated portion of the device. The coating of the cylindrical surface through is interrupted to define clear rings on the cylindrical surface which light from the lamp box is conducted to be reflected from the cornea.
摘要:
Embodiments provided herein generally relate to improved ultrasound visualization. In some embodiments, interoperative ultrasound displays may be enhanced for more accurate identification of cancerous and non-cancerous tissues.
摘要:
The present invention relates to a method for segmenting speech into subword speech segments. Optimal boundary locations for each estimate of a number of segments are determined within an estimated range of the number of segments. In addition, an optimality criteria is found for each estimate of the number of segments within the range. Using the optimality criteria, the optimal number of subwords are determined. From the location of the boundaries and the optimal number of segments, data can be clustered or speech can be segmented. The method can be used in data processing systems, speaker verification, medium size vocabulary speech recognition systems, language identification systems and coarse subword level speech segmentation processes.
摘要:
The present invention relates to a pattern recognition system which uses data fusion to combine data from a plurality of extracted features and a plurality of classifiers. Speaker patterns can be accurately verified with the combination of discriminant based and distortion based classifiers. A novel approach using a training set of a "leave one out" data can be used for training the system with a reduced data set. Extracted features can be improved with a pole filtered method for reducing channel effects and an affine transformation for improving the correlation between training and testing data.
摘要:
A microscope having a high effective numerical aperture (NA) is achieved in an apparatus in which a real, three-dimensional image is formed of an object placed in an aperture at the apex of one of two facing, axially-aligned concave mirrors. The three-dimensional image is acquired by a video camera positioned in a counterpart aperture at the apex of the other mirror and the acquired image is processed by computer. The processing corrects the acquired image using the point spread function of the mirror system which was previously obtained by positioning a point source of light throughout the object space and measuring the pixel values recorded by the camera's array of sensing element while the camera was positioned at different axial distances in the image space. When the diameter of the mirrors is large compared to the specimen object, substantially all of the light leaving the specimen is captured by the mirrors and focused upon the camera, thereby achieving a high effective numerical aperture for the system which affords excellent resolution, especially when examining transparent specimens.
摘要:
Processing of the two-dimensional image of a three-dimensional object, such as the human cornea, that has been illuminated with a structured light pattern. A specially filtered Fourier transform and inverse transform are processed to yield the instantaneous spatial frequencies of the illuminated pattern. The instantaneous spatial frequencies are mapped to the instantaneous dioptric powers or depth coordinates of the object's surface.