Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. A method to estimate a strain rate in any direction, not necessarily along the ultrasound beam, based on tissue velocity data from a small region of interest around a sample volume is disclosed. Quantitative tissue deformation parameters, such as tissue velocity, tissue velocity integrals, strain rate and/or strain, may be presented as functions of time and/or spatial position for applications such as stress echo. For example, strain rate or strain values for three different stress levels may be plotted together with respect to time over a cardiac cycle.

Abstract: A method and apparatus for detecting cardiac events. Ultrasonic data comprising a heart cycle is acquired by a probe. Tissue velocities associated with the ultrasonic data are detected. One of a maximum and a minimum value is detected based on the tissue velocities. A time within the heart cycle associated with the maximum or minimum value is determined, and a cardiac event is detected with respect to the time within the heart cycle and the maximum or minimum value.

Abstract: A trigger extraction system for obtaining an event trigger for an event occurring in a region of interest includes a processor, a memory coupled to the processor, and a trigger extraction program stored in the memory for execution by the processor. The trigger extraction program includes instructions for accessing ultrasound trigger data from a trigger region intersecting a region of interest, analyzing the trigger data for a trigger characteristic, and storing an event trigger based on the trigger characteristic.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. An ultrasound acquisition technique that allows a high frame rate in tissue velocity imaging or strain rate imaging is employed. With this acquisition technique the same ultrasound pulses are used for the tissue image and the Doppler based image. A sliding window technique is used for processing. The tissue deformation parameter strain is also determined by an accumulation of strain rate estimates for consecutive frames over an interval. The interval may be a triggered interval generated by, for example, an R-wave in an ECG trace. The strain calculation may be improved by moving the sample volume from which the strain rate is accumulated from frame-to-frame according to the relative displacement of the tissue within the original sample volume. The relative displacement of the tissue is determined by the instantaneous tissue velocity of the sample volume.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. The tissue deformation parameter strain is determined by an accumulation of strain rate estimates for consecutive frames over an interval. The interval may be a triggered interval generated by, for example, an R-wave in an ECG trace. Three quantitative tissue deformation parameters, such as tissue velocity, tissue velocity integrals, strain rate and/or strain, may be presented as functions of time and/or spatial position for applications such as stress echo. For example, strain rate or strain values for three different stress levels may be plotted together with respect to time over a cardiac cycle. Parameters which are derived from strain rate or strain velocity, such as peak systolic wall thickening percentage, may be plotted with respect to various stress levels.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. A method to estimate a strain rate in any direction, not necessarily along the ultrasound beam, based on tissue velocity data from a small region of interest around a sample volume is disclosed. Quantitative tissue deformation parameters, such as tissue velocity, tissue velocity integrals, strain rate and/or strain, may be presented as functions of time and/or spatial position for applications such as stress echo. For example, strain rate or strain values for three different stress levels may be plotted together with respect to time over a cardiac cycle.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. Tissue velocity may be estimated by filtering a received ultrasound signal at three center frequencies related to the second harmonic of the ultrasound signal, estimating a reference tissue velocity from the two signals filtered at the outside center frequencies and using the reference tissue velocity to choose a tissue velocity from tissue velocities estimated using the middle center frequency. Estimation of strain rate in any direction, not necessarily along the ultrasound beam, is disclosed. Quantitative tissue deformation parameters may be presented as functions of time and/or spatial position for applications such as stress echo. For example, strain rate or strain values for three different stress levels may be plotted together with respect to time over a cardiac cycle. Parameters derived from strain rate or strain velocity may be plotted with respect to various stress levels.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. An ultrasound acquisition technique that allows a high frame rate in tissue velocity imaging or strain rate imaging is employed. With this acquisition technique the same ultrasound pulses are used for the tissue image and the Doppler based image. A sliding window technique is used for processing. The tissue deformation parameter strain is also determined by an accumulation of strain rate estimates for consecutive frames over an interval. The interval may be a triggered interval generated by, for example, an R-wave in an ECG trace. The strain calculation may be improved by moving the sample volume from which the strain rate is accumulated from frame-to-frame according to the relative displacement of the tissue within the original sample volume. The relative displacement of the tissue is determined by the instantaneous tissue velocity of the sample volume.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters, such as tissue Doppler and strain rate imaging, are disclosed. An ultrasound acquisition technique that allows a high frame rate in tissue velocity imaging or strain rate imaging is employed. With this acquisition technique the same ultrasound pulses are used for the tissue image and the Doppler based image. The number of beams used in Doppler subframes are increased to allow tissue visualization based only on Doppler subframes. A sliding window technique is used for processing.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters, such as tissue Doppler and strain rate imaging, are disclosed. An ultrasound acquisition technique that allows a high frame rate in tissue velocity imaging or strain rate imaging is employed. With this acquisition technique the same ultrasound pulses are used for the tissue image and the Doppler based image. The number of beams used in Doppler subframes are increased to allow tissue visualization based only on Doppler subframes. A sliding window technique is used for processing.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. An ultrasound acquisition technique that allows a high frame rate in tissue velocity imaging or stain rate imaging is employed. The tissue deformation parameter strain is determined by an accumulation of stain rate estimates for consecutive frames over an interval. The interval may be a triggered interval generated by, for example, an R-wave in an ECG trace. The strain calculation may be improved by moving the sample volume from which the stain rate is accumulated from frame-to-frame according to the relative displacement of the tissue within the original sample volume. The relative displacement of the tissue is defined by the instantaneous tissue velocity of the sample volume. An estimation of strain rate based upon a spatial derivative of tissue velocity is improved by adaptively varying the spatial offset, dr. The spatial offset, dr, can be maximized to cover the entire tissue segment (e.g.

Abstract: A system and method for acquiring ultrasound information at an acquisition rate and displaying at least a portion of the acquired ultrasound information at a display rate that is slower than the acquisition rate is disclosed. Ultrasound information may be continuously acquired and stored at a frame-rate that is greater than the perception rate of the human eye. At least a portion of the acquired ultrasound information is displayed at a frame-rate that allows human perception. Acquisition and display are synchronized from time-to-time upon satisfaction of a synchronization condition. The synchronization condition may be related to a predetermined time interval or a triggering event generated by or through triggering generated by, for example, a physiological event detected in, for example, an ECG trace.

Abstract: An ultrasound system and method for calculation and display of strain velocity in real time is disclosed. Strain velocity may be determined from tissue velocity. Tissue velocity determined by measuring the pulse-to-pulse Doppler shift at range positions along an ultrasound beam and calculating tissue velocity based on the Doppler shift. The strain velocity is then calculated as a gradient of tissue velocity. Alternatively, linear regression methods may be used to calculate strain velocity from tissue velocity. Alternatively, strain velocity may be determined directly from the difference in Doppler shift between range positions. The result of the strain velocity determination may be displayed in a number of manners such as M-mode, color-coded video images or time-variation curves, and may be displayed in combination, or as a mixture, with a B-mode image. A reliability index may be calculated and used to modify the display of strain velocity information.

Abstract: Method for determining the velocity-time spectrum of blood flow in a living body by means of an ultrasonic pulsed wave Doppler system, comprising:sequential transmission of pulsed ultrasonic waves and receiving a corresponding sequence of echo signals,sampling the received echo signals at one or more predetermined time delays after transmitted ultrasonic pulses, andprocessing said sequence of echo signal samples by frequency spectrum analysis to obtain a blood velocity spectrum comprising a number of velocity components within a range of expected blood velocity values, andrepeating said processing a plurality of times to obtain a velocity-time spectrum for substantially real-time display.

Abstract: A method for velocity estimation based on a complex demodulated doppler signal in a multi-gated doppler. The method is based on the autocorrelation function estimates of the complex demodulated doppler signal. Contribution to the correlation function from the receiver noise is found by measuring the noise in absence of echo signals. The obtained values are subtracted from the correlation estimates before further processing. A limited number of candidates for the true velocity are calculated from the autocorrelation function phase.