Method of displaying stream lines of an inhomogeneous flowing medium and a device therefor

A device for displaying in real time, on a cathode ray tube, a stream line of an inhomogeneous flowing medium by scanning an object in which said inhomogeneous flowing medium is situated with ultrasonic wave beam pulses and processing echoes thereof reflected from the object, said device comprising:

• transducer means for converting electrical energy to ultrasound energy and vice versa and for sending out ultrasound beam pulses and receiving the echoes;
• transmitting and receiving circuit means, operatively connected to said transducer means, for exciting the transducer means to generate the beam pulses so as to scan the object plural times within a predetermined time interval, receiving echo signals from the transducer and converting the echo signals into electrical signals;
• echo signal generator means, operatively connected to said transmitting and receiving circuit means, for processing the electrical signals and for providing a digital echo signal suitable for image processing;
• sub-frame memory means for storing the digital echo signal;
• stream line processor means for processing the data stored in said sub-frame memory means to obtain data of segments of stream lines;
• image memory means for storing the data of the segments of the stream lines;
• and
• display means for retrieving the data stored in said image memory means and generating an image signal for the segments of stream lines to display on the cathode ray tube.

A method of displaying stream lines in an inhomogeneous flowing medium, comprising the steps of:

• (a) repetitively scanning the medium with an ultrasonic beam;
• (b) obtaining stream line images by substracting an echo image of a first beam scan from an echo image of a second scan;
• and
• (c) displaying the stream line images.