Method and apparatus for pulsed doppler ultrasound beam-forming

摘要

This invention addresses the aliasing and range ambiguity artifact trade-off occurring in pulsed doppler ultrasound applications. By increasing pulse repetition frequency to avoid aliasing and by implementing non-coinciding transmit and receive beam-patterns, range ambiguity effects are reduced. Separate transmit and receive apertures define respective transmit and receive beam-patterns. These separate transmit and receive beam-patterns intersect at a primary range gate. Secondary range gates may occur along the receive beam-pattern. The transmit beam-pattern does not intersect such secondary gates. Weaker dispersed ultrasound energy may intersect the secondary gates, however, and reflect back to the receive aperture. Relatively stronger samples are obtained from the primary range gate than from the secondary range gates. In effect the geometry of the transmit and receive beam-patterns maximizes the strength of the response from the primary gate and reduces the strength of the response from the secondary gates.