Abstract: A pulsed Doppler technique uses coded excitation on transmit and pulse compression on receive. Coded excitation allows a long transmit pulse to be compressed on receive such that most energy is concentrated in a short interval. In the case of a single coded transmit for each transmit focal position, the receive signals are compressed utilizing matched or mismatched filtering. In the case of a two or more coded transmits for each transmit focal position, the receive signals are compressed utilizing filtering coefficients which match the respective transmit codes during each firing. These techniques can be used to maximize Doppler sensitivity of a small but deep-lying sample volume. Alternatively, for a given transmit acoustic burst length and dosage, the sample volume can be reduced to achieve better spatial resolution without compromising sensitivity.
Abstract: An apparatus and methods for determining a measure equivalent to broadband sound attenuation from transient or other measures derived from acoustic signals propagated through bone and, additionally, for using this measure for the calibration of an ultrasound bone analysis instrument. A synthetic mathematical filter corresponding to a given value of broadband ultrasound attenuation is applied to the signal propagated through a calibration of known or neutral acoustic properties. The value of the acoustic measure corresponding to the resultant waveform is determined and associated with the broadband ultrasound attenuation value corresponding to the synthetic mathematical filter. A model relating the acoustic measure to BUA values may thereby be established for subsequent clinical application.
Abstract: An apparatus and methods determine externally in a vertebrate subject the porosity and non-connectivity of a bone. A preferred embodiment has an acoustic transceiver with a pair of acoustic transducers disposed in a specified spatial relationship with one another, such that an acoustic signal is transmitted from one to another via the bone. The transmission path through the bone corresponding to the acoustic signal analyzed by the system may be varied, with values derived from measures of acoustic transmission through differing locations in the bone stored in different locations of a memory. A location processor is provided for selecting a target location based at least in part on the values stored in the memory for defining a region of interest with respect to which a measure of bone porosity is determined.
Abstract: The present invention includes a fully programmable plurality of multi-channel receivers, each receiver having a digital multi-channel receive processor and a local processor control. Each receive processor includes a first decimator, time delay memory, second decimator, and complex multiplier. The receive beamformer is a computationally efficient system which is programmable to allow processing mode trade-offs among receive frequency, receive spatial range resolution, and number of simultaneous beams received. Each local control receives focusing data from a central control computer and provides final calculation of per-channel dynamic focus delay, phase, apodization, and calibration values for each receiver signal sample. Further, this invention includes a baseband multi-beam processor which has a phase aligner and a baseband filter for making post-beamformation coherent phase adjustments and signal shaping, respectively.
Type:
Grant
Filed:
January 24, 1997
Date of Patent:
March 16, 1999
Assignee:
Acuson Corporation
Inventors:
J. Nelson Wright, Christopher R. Cole, Albert Gee
Abstract: A scanning ultrasonic apparatus provides measurements of a bone at a number of spatially separated locations. These measurements may produce an image or may be used to automatically identify a measurement region of interest or to align a series of measurements with each other despite possible shifting in the bony member in between measurements.
Type:
Grant
Filed:
February 4, 1997
Date of Patent:
November 24, 1998
Assignee:
Lunar Corporation
Inventors:
Richard B. Mazess, Richard F. Morris, Scott A. Wiener
Abstract: A bone assessment apparatus for obtaining an assessment value E for a bone 12 with good repeatability by simple calculation using the waveform of a signal derived from received ultrasound which has passed through the bone. A transmitting transducer (20) transmits an ultrasound pulse. A receiving transducer (22) receives the ultrasound pulse which has passed through a test sample (10), and then converts the received ultrasound pulse to a signal. An A/D converter (30) digitizes the signal amplified in a receiving amplifier (28). The digitized signal is inputted to a calculator (32) via a transducer controller (26). The calculator (32) calculates the assessment value E for the bone (12) from characteristic values of the waveform of the signal, such as the half-value width of the first positive portion, which are derived from ultrasonic transmission characteristics of the bone (12).
Abstract: Subtle changes in heart wall motion which may be symptomatic of coronary disease states are more easily discerned by acquiring a real time sequence of ultrasonic diagnostic images. An image acquired at a predetermined point in the cardiac cycle, such as the end diastole image, is chosen as a mask image, and the heart wall in the mask image is colored a first color. The heart wall in the remaining images in the sequence is colored a second, contrasting color. The contrasting images are then successively displayed in overlapping alignment with a static display of the mask images Abnormalities in heart wall motion are more easily discerned by the relative motion between the contrasting image sequence and the mask image.
Abstract: An ultrasonic image processing for accurately detecting the annulus portion from the ultrasonic image of the long axis view of a heart. A heart wall contour is extracted from the ultrasonic image, and a center of gravity of the heart wall contour is determined. Then, for an image imaged from an apex portion side, the annulus portion is detected from points on the heart wall contour located at positions deeper than the center of gravity, whereas for an image imaged by a transesophageal echocardlography, the annulus portion is detected from points on the heart wall contour located at positions shallower than the center of gravity.