Hewlett-packard Company

Stephen M Grenon

Randal B Chinnock

Benjamin T Gravely

William L Weber

Richard Allen Snyder

Gregory G Vogel

Sharon A Gadonniex

John M Jans

The method of the invention employs pulsed Doppler ultrasound signals to color image blood and tissue movement velocities in a body. The method initially images a movement with a transmitted ultrasound signal that manifests a current signal transmission frequency value and a current pulse repetition frequency (PRF) value. Those values exhibit a determined ratio R to each other. Thereafter, in response to an indication by the user that movement is to be imaged at a new depth, the method alters the current transmission frequency to a new frequency to provide improved signal back-scatter from movement at the new depth. Then, the current PRF is adjusted, automatically, to a new PRF value which, when compared to the new transmission frequency, manifests substantially the same determined ratio R that was present between the current transmission frequency and current PRF. The latter step assures that the mapping of movement velocity values to colors is maintained, notwithstanding use of a new transmission frequency.

Method for maintaining a constant velocity to color map in an ultrasound

A phased array ultrasound imaging system includes a transducer with multiple transducer elements disposed along a lateral axis. The transducer has an aperture with an elevation dimension parallel to an elevation axis that increases between the midpoint of the aperture along the lateral axis and the ends of the aperture along the lateral axis. The elevation dimension can increase continuously and/or in steps between the midpoint and each end of the aperture. Portions of the aperture can have a constant elevation dimension. When the transducer is used in an ultrasound imaging system, an active receive aperture dynamically increases in size during reception of ultrasound energy from progressively increasing depths, thereby providing dynamic elevation focusing. The transmit aperture size can be selected to optimize both lateral and elevation focii. Electronic compensation can be used to control the transmit and receive beam patterns.

Phased array ultrasound imaging system with dynamic elevation focusing

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Manchester, NH, United States of America

Stephen M Grenon