Abstract: A medical diagnostic ultrasound system comprises several subsystems, such as a transmit beamformer, a receive beamformer, a B-mode processor, a Doppler processor and a scan converter. These subsystems are within the ultrasound data processing path for processing ultrasound data. One or more of these subsystems are implemented with one or more re-programmable logic devices. For example, one or two field programmable gate arrays are used is each subsystem to perform most or almost all of the subsystems essential functionality.

Abstract: The same analytic data is combined in response to different relative phases. The resulting combinations are detected. The combination associated with the maximum magnitude is then selected for further processing. As a result, the complex data is processed across a variety of possible temporal discontinuities using candidate or possible phase shifts. The phase shift with the least cancellation and the associated combination is selected to minimize motion artifact cancellation.

Abstract: A method and apparatus for extracting an envelope curve of a spectrogram, for use in measurement of blood flow velocity by using spectral Doppler techniques, the method comprising steps of: processing RF ultrasound echo signals to obtain Doppler signals; performing spectral analysis on the Doppler signals, to obtain a corresponding power spectrum P(f); estimating a forward maximum frequency fmax+ and a backward maximum frequency fmax? for the Doppler signals at a predetermined moment, according to the power spectrum P(f) of the Doppler signals at the predetermined moment; determining a noise frequency range according to the two maximum frequencies, so as to estimate an average noise power E; and correcting the forward maximum frequency and the backward maximum frequency by using the average noise power E. With the method of the invention, influence from the SNR and bandwidth on the envelope curve may be reduced, so as to be useful for accurate computation of blood flow parameters.

Abstract: A method of measuring blood flow including several steps. In an initial step a first ultrasound beam is oriented in a direction substantially perpendicular to the direction of the blood flow to be measured. Next, the Doppler spectrum obtained from the backscattered echoes of said first ultrasound beam is measured. Subsequently, the ultrasound beam is reoriented so that the Doppler spectrum of the backscattered echoes of the ultrasound beam is substantially symmetrical around the zero frequency. The Doppler frequency of the backscattered echoes of a second ultrasound beam oriented at a fixed angle to the first ultrasound beam is then measured. Finally, the rate of blood flow is calculated based on the angle between the ultrasound beams and the measured Doppler frequency of the backscattered echoes of the second ultrasound beam.

Abstract: System and method for automatically measuring the delay of tissue motion and deformation. For example, asynchrony may be measured between the left and right ventricles and within the left ventricle. A measurement feature may be defined by default or obtained using a user input. A reference time and a search interval are identified. The search interval may be based on the reference time, or input or modified by a user. A time delay of the measurement feature within the search interval is calculated for each sample. At least one color is assigned to the samples corresponding to the calculated time delay.

Abstract: Featured is an MRI/NMR methodology or process to detect amide protons of endogenous mobile proteins and peptides via the water signal. Such methods and processes can be used for the purposes of detection of pH effects and labile amide proton content of mobile proteins/peptides or content changes thereto using MRI Also featured are methods whereby assessment of determined pH effects and amide proton content or content changes and related mobile protein and/or peptide content or content changes can be used in connection with diagnosis, program and treatment of brain related disorders and diseases, cardiac disorders and diseases, and cancer and to use such methods for monitoring, detecting and assessing protein and peptide content in vivo and pathologically for any of a number of diseases or disorders of a human body, including but not limited to cancers, ischemia, Alzheimers and Parkinsons.

Abstract: A method for determining the volume of an irregularly shaped body part or body such as a fetus using a 3D ultrasonic image composed of light and dark pixels. A caliper is placed on a portion whose volume is to be determined and a computer having the image, automatically counts every pixel with the same echogenicity in every direction as long as it is continuous with the spot the caliper is in, and wherein the computer means stops counting in any direction where the pixels become significantly more echogenic (dark). The volume of the portion, is determined, based on the counted number of pixels and the magnification of the image; and the calculated volume is used to determine physiological characteristics based on known values such as fetal gestation age.

Abstract: A medical diagnostic ultrasonic imaging system acquires receive beams from spatially distinct transmit beams. The receive beams alternate in type between at least first and second types across the region being imaged. The first and second types of receive beams differ in at least one scan parameter other than transmit and receive line geometry, and can for example differ in transmit phase, transmit or receive aperture, system frequency, transmit focus, complex phase angle, transmit code or transmit gain. Receive beams associated with spatially distinct ones of the transmit beams (including at least one beam of the first type and at least one beam of the second type) are then combined. In this way, many two-pulse techniques, including, for example, phase inversion techniques, synthetic aperture techniques, synthetic frequency techniques, and synthetic focus techniques, can be used while substantially reducing the frame rate penalty normally associated with such techniques.

Abstract: A method of estimating the volume flow in a vessel utilizing ultrasound techniques including the steps of imaging the vessel utilizing an ultrasonic transducer array so as to produce fluid velocity information for the vessel, the plane formed by the beams emitted by the transducers having a direction which is offset from an axis of the vessel such that the beam plane forms an elliptical section within the vessel, and utilizing the velocity information for points within the vessel and the elliptical section to calculate a mean velocity for the fluid flow through the elliptical section. The improvement of the volume flow estimation is achieved by utilizing average velocity information and Doppler signal power, and mean velocity calculation based on a weighted summation of the velocity values a multiple measurement points with weighting factors determined by the Doppler signal power at the measurement points.

Abstract: Two-dimensional distribution data of velocities on a moving object in an object to be examined is obtained. A motion field which defines the motion direction of a tissue is stored. A plurality of tracking points are obtained in a tissue range in the two-dimensional distribution data. The moving positions of the tracking points are estimated and the positions are sequentially tracked. Velocities toward the motion direction defined by the motion field are obtained on the basis of the two-dimensional distribution data. One intermediate output value is obtained by performing a predetermined computation by using velocities toward the motion direction at tracking positions of at least two tracking points in each time phase. The values of intermediate positions are obtained by performing weighted addition of intermediate outputs at different positions. A display image is generated and displayed by using the values of the intermediate positions.

Abstract: A strobed blood flow meter provides periodic measurements of blood flow velocity or volumetric blood flow over a cardiac cycle at reduced average power consumption, which is advantageous for reducing battery size, and extending device battery life, such as in an implantable application. Continuous wave Doppler, pulsed Doppler, laser Doppler, transit time, electromagnetic flow, and thermal dilution techniques are included. Strobing provides higher level excitation during active periods, which improves signal-to-noise ratio, and provides a low power standby mode during an idle time between active periods. The invention may be used for chronic or acute applications. Doppler or other signals may be telemetered from an implanted portion of the flow meter for further signal processing to extract velocity or volumetric flow. Alternatively, such signal processing is also implanted, such that the velocity signal can be telemetered to an remote monitor.

Abstract: An ultrasonic Doppler flow phantom is described which is formed of tissue-mimicking material containing a plurality of fluid flow paths through which fluid is pumped. The fluid flow paths are made of tubing and each extends over a different portion of the depth of the phantom and at a different angle. Each path is individually accessible by a probe located on the simulated skin surface at the top of the phantom, enabling the performance of the probe to be evaluated over a wide range of depths from shallow to very deep and over several flow angles.

Abstract: An ultrasound machine that generates a color representation of moving structure, such as cardiac wall tissue within a region of interest, and is displayed on a monitor. The color representation is generated by displaying at least one color characteristic related to a set of signal values of the structure, such as velocity or strain rate. The related feature of the set of signal values is mapped to the color characteristic by an apparatus comprising a front-end that generates received signals in response to backscattered ultrasound waves. A Doppler processor generates a set of signal values representing a spatial set of values of the moving structure. A host processor embodies a tracking function and a time integration function to generate tracked movement parameter profiles and displacement parameter values over a time period corresponding to sampled anatomical locations within the region of interest. The displacement parameter values are then mapped to color characteristic signals.

Abstract: An ultrasonic imaging system uses a specially configured scanhead to provide ultrasound return signals that are processed by an imaging unit to generate a three-dimensional Doppler ultrasound image. One embodiment of the scanhead includes a first pair of apertures aligned along a first axis, and a second pair of apertures aligned along a second axis that is perpendicular to the first axis. All of the apertures lie in a common plane. Respective signals from the apertures along each axis are processed to generate two-dimensional Doppler motion vectors. The resulting pairs of two-dimensional Doppler motion vectors are then processed to generate three-dimensional Doppler motion vectors that are used to generate a three-dimensional Doppler image. In another embodiment, three co-planar apertures are arranged equidistantly from each other about a common center, and the three-dimensional Doppler image is generated from respective signals from the apertures.

Abstract: An ultrasound machine is disclosed that generates a color representation of moving structure, such as a cardiac wall tissue within a region of interest, and is displayed on a monitor. The color representation is generated by displaying at least one color characteristic related to a movement parameter of the structure, such as mean velocity or mean strain rate. The related feature of the movement parameter is mapped to the color characteristic by an apparatus comprising a front-end that generates received signals in response to backscattered ultrasound waves. A Doppler processor generates a set of parameter signals representing a spatial set of values of the movement parameter within the structure. A host processor embodies a tracking function and a peak-detection function to generate a set of tracked movement parameter profiles and a set of peak values of the movement parameter over a time period corresponding to anatomical locations within the region of interest.

Abstract: Techniques are provided for obtaining selected instantaneous area measurements for a dynamic orifice through which blood is flowing in at least one direction, for obtaining instantaneous flow rates of blood passing through such a dynamic orifice and for obtaining flow volume for blood passing through a dynamic orifice. All of these techniques involve ensonifying a thin sample volume of blood flow exiting at the orifice, which volume is in a region of flow which is substantially laminar, such region normally being the vena contracta for the orifice, with an ultrasonic pulsed Doppler signal, receiving backscattered signal from blood within the sample volume and forming a power-velocity spectrum from the received backscattered signal. Techniques are disclosed for assuring that only laminar flow is looked at in forming the power-velocity spectrum.

Abstract: An ultrasound scanning system (10) includes a plurality of range gates (71-74) responsive to ultrasound waves for generating a plurality of Doppler signal samples representing different depth increments within a subject (S) being studied. A logic unit (30) generates Doppler frequency signals and generates B-mode data. A display (60) generates a B-mode image and a Doppler image which may be superimposed on the B-mode image. The Doppler image (DI) is arranged to illustrate depth increments within the subject being studied versus Doppler velocity or frequency.

Abstract: An ultrasound system determines the relative movement in a first direction (F1) of first matter, such as blood flow, and second matter, such as an artery wall, in a subject under study (S). A beam (B1) of ultrasound waves defining a plurality of beam positions (BP1 and BP2) and beam axes (A1and A2) are moved in scan directions having components parallel to direction F1. First and second blocks of data representing the first and second matter, respectively, are generated. A processor (20) performs an estimation of speckle size on first data to obtain a first result, and performs analysis of the second block of data to obtain a second result. The two results are analyzed to obtain a measure of the relative movement of the first and second matter.

Abstract: A system for estimating the volume of fluid in the bladder sequentially scans the bladder with ultrasonic beams that section the bladder into a number of transverse planes. The system determines, from the scan lines associated with a given plane, a plurality of points on each of the front and back walls of the bladder. It then fits a curve to the set of front wall points and another curve to the set of back wall points, to determine an outline of the bladder in the plane. The system next calculates the cross sectional area of the bladder in the plane based on the two curves. After determining the area in each of the planes, the system determines the volume of the bladder by summing weighted version of the planar areas. The system includes a transducer that consists of a plurality of piezo-electric elements held in a relatively thin elastomeric pad and/or substrate that is acoustically impedance matched to skin.

Abstract: An anatomical visualization system is provided which includes a first database comprising a plurality of 2-D slice images generated by scanning a structure. The 2D slice images are stored in a first data format. A second database comprising a 3-D computer model of the scanned structure is also provided. The 3-D computer model includes a first software object defined by a 3-D geometry database. Apparatus is provided for inserting a second software object into the 3-D computer model so as to augment the 3-D computer model. The second software object is defined by a 3-D geometry database, and includes a planar surface. Apparatus for determining the specific 2-D slice image associated with the position of the planar surface of the second software object within the augmented 3-D computer model are provided in a preferred embodiment. Also provided are apparatus for texture mapping the specific 2-D slice image onto the planar surface of the second software object.

Abstract: A system is disclosed for measuring volume flow through vessel. A longitudinal area of a vessel in a body is scanned using a color Doppler imaging method, such that an imaging plane is formed approximately through the center of said vessel. A number of color pixels in a scanned cross-section of the vessel in which volume flow is detected are counted and tabulated. From this number of pixels, an observed cross-sectional area of the vessel is determined. Frequency shift information for each of the counted pixels is determined and these frequency shifts are spatially averaged. The instantaneous volume flow through the vessel is then computed from the cross-sectional area and frequency shift information. The volume flow for several different samples is computed. The instantaneous volume flows from each color Doppler imaging frame are temporally averaged over one or more integral cardiac cycles to compute a temporally-averaged volume flow.

Abstract: In an ultrasound system and method, a transducer connects to an estimator for obtaining first and second blood flow parameters associated with first and second scan line directions, respectively, in a first scan plane. One beam substantially covering a cross-sectional area of a tubular structure (uniform insonification) or a plurality of beams may be used. A first area associated with the cross-section of the tubular structure is also estimated from the blood flow parameters. The process is repeated for a plurality of scan planes. A processor determines the cross-sectional area of the tubular structure perpendicular to its axis (a second area), the average velocity of flow parallel to the axis, and the volume flow as a function of the first area and the first and second blood flow parameters of all the scan planes. For real-time volume flow, the orientation of the tubular structure is determined using the second area and the first and second blood flow parameters.

Abstract: A method for generating color Doppler images is implemented in real time using digital processing steps implemented on multi-purpose microprocessors. Processing is reduced by estimating velocity only when a tissue threshold decision for a given sample indicates that the sample is not tissue. Arc tangent calculations in the velocity estimation are performed using simplified look-up tables without sacrificing accuracy. One look-up table is lineraly quantized. A second is nonlinearly quantized.

Abstract: A method and an apparatus for mitigating aliasing when imaging moving fluid or tissue using velocity Doppler shift data. To eliminate the effects of slight aliasing in the velocity mode, symmetrical (or non-directional) velocity/color maps are used to map positive and negative velocity data of the same magnitude to the same color and same display intensity. If the pulse repetition frequency is adjusted so that only subtle aliasing is present, an optimal frame averaging of the data can be achieved by removing the sign of the velocity data either before or during frame averaging.