Patent ID: 6210332
Filing Date: 2001-04-03
Classification: G01S,Y10S

Abstract:
An imaging system comprising:a transducer array having a multiplicity of transducer elements for transmitting wave energy centered at a fundamental frequency in response to electrical activation and for transducing returned wave energy into electrical signals;a transmitter coupled to said transducer array and programmed to activate a plurality of said transducer elements to transmit focused wave energy encoded with a transmit code during first and second transmit events;a receiver programmed to respectively form first and second receive signals from electrical signals produced by said plurality of transducer elements subsequent to said first and second transmit events respectively;a wall filter programmed with first and second sets of filter coefficients to compress and bandpass first and second fundamental signal components of said first and second receive signals respectively and selectively pass frequencies corresponding to wave energy reflectors moving at a velocity above a predetermined threshold, the wall filter forming a flow signal derived at least in part from the compressed and bandpassed first and second fundamental signal components and the selectively passed frequencies; anda subsystem for displaying an image having an image portion which is a function of at least said flow signal.