Ultrasonic Doppler imager having an adaptive tissue rejection filter with enhanced tissue motion sensitivity

Claim 1

In an ultrasonic flow imaging and/or measuring system of the type including: a transmitter/receiver arrangement for transmitting a plurality of three or more ultrasonic pulses, for each of a plurality of differently directed beamlines, into an area to be scanned and developing a corresponding plurality of acoustic line signals for each beamline in response to processing of received reflections of said transmitted ultrasonic pulses; a flow processor for processing said acoustic line signals and developing therefrom estimate signals representative of movement in said scanned area; and, a tissue (non-flow) motion rejection arrangement responsive to a control signal representative of tissue movement in said scanned area for preprocessing said acoustic signals provided to said flow processor so as to suppress tissue movement contributions to said estimate signals, an improvement comprising: a corner turning memory for receiving and storing said acoustic line signals as a plurality of sequential samples for each acoustic line of each beamline; and a tissue velocity estimator, coupled to be responsive to samples of said acoustic line signals as provided by said corner turning memory for developing therefrom said control signal, wherein said corner turning memory is caused to provide said acoustic line samples to said tissue velocity estimator in a manner so that all the sequential samples of one or more of said acoustic lines received by said memory are periodically skipped as said memory provides said samples to said tissue velocity estimator.

Claim 17

A method for processing scanning beamlines of received ultrasound signals in an ultrasound flow imaging system so as to develop flow signals in which contributions to said flow signals of ultrasonic reflections from non-flow movement are suppressed, said method comprising the steps of: transmitting and receiving ultrasonic waves for developing a plurality of beamlines which scan an area, each beamline including a plurality of three or more acoustic lines of signal samples in response to the receipt of reflections from ultrasonic waves transmitted into the area during the scan; storing in a memory said acoustic lines of signal samples as a plurality of sequential digital samples for each acoustic line, and subsequently supplying from said memory said samples during a read-out mode; flow processing said acoustic lines of signal samples as provided by said corner turning memory during said read-out mode for detecting a Doppler shift in said samples and developing velocity estimate signals therefrom; tissue processing said velocity estimate signals for developing therefrom a control signal representative of the movement of tissue; tissue rejection filtering said acoustic line samples in response to said control signal, for causing said filter arrangement to suppress tissue movement signals from said acoustic line samples applied to said signal input of the tissue rejection filter arrangement; and controlling said memory during supply of acoustic line signal samples used for flow processing, so as to periodically skip one or more of said acoustic lines of samples as said lines are provided from a first one of said lines to a last one of said lines, for flow processing.

Claim 18

A method for processing scanning beamlines of received ultrasound signals in an ultrasound flow imaging system so as to develop flow signals in which contributions to said flow signals of ultrasonic reflections from non-flow movement are suppressed, said method comprising the steps of: transmitting and receiving ultrasonic waves for developing a plurality of beamlines which scan an area, each beamline including a plurality of three or more acoustic lines of signal samples in response to the receipt of reflections from ultrasonic waves transmitted into the area during the scan; storing in a memory said acoustic lines of signal samples as a plurality of sequential digital samples for each acoustic line, and subsequently supplying from said memory said samples during a read-out mode; flow processing said acoustic lines of signal samples as provided by said corner turning memory during said read-out mode for detecting a Doppler shift in said samples and developing velocity estimate signals therefrom; tissue processing said velocity estimate signals for developing therefrom a control signal representative of the movement of tissue; tissue rejection filtering said acoustic line samples in response to said control signal, for causing said filter arrangement to suppress tissue movement signals from said acoustic line samples applied to said signal input of the tissue rejection filter arrangement; and controlling said memory during supply of acoustic line signal samples used for flow processing, so as to periodically skip one or more of said acoustic lines of samples as said lines are provided from a first one of said lines to a last one of said lines, for flow processing.