Sri International

Siemens Aktiengesellschaft

S David Ramsey, Jr

Philip S Green

Jon C Taenzer

John F Holzemer

Louis F Schaefer

Donald J Burch

David A Wilson

James L Buxton

Joe R Suarez

An ultrasonic imaging system (50) has an array (52) of transducer elements (54-1 through 54-21) for receiving ultrasonic signals reflected from within an inhomogeneous object (16) being examined. The system (50) has a means (80, 84, 88, 94) connected to generate an image in response to the ultrasonic signals. A cross-correlator (70) is connected to compare the signals received by the transducer elements (54-1 through 54-21). An output addressing circuit (130) is connected to inhibit or otherwise modify gain of selected ones of the signals based on the comparison to reduce multipath ultrasonic wave interference, refraction or obstruction image distortion or degradation. A preferred ultrasonic imaging array (52) for this purpose and for time delay image distortion correction has a plurality of segmented, annular transducer elements (54-2 through 54-21). The elements (54-2 through 54-21) are formed as sectors of circles with substantially equal arc lengths. A digital signal processing circuit for the system (50) has a plurality of dual port RAMs (66-1 through 66-21) as delay lines and a cross-correlator (70) including an output addressing circuit (130) controlled by a microcomputer (128). The output addressing circuit (130) generates addresses for output of information from the dual port RAM delay lines (66-1 through 66-21) to accomplish time delay correction and elimination or other gain modification of ultrasonic signals with multipath interference, refraction or obstruction.

Ultrasonic imaging system with correction for velocity inhomogeneity and

The insonification apparatus is designed for the examination of an object, preferably for medical examinations. The apparatus contains an ultrasonic wave-generating transducer for emitting ultrasonic waves toward an examination plane, and an imaging device having principal planes for passing ultrasound waves received from the examination plane toward an imaging plane. The acoustic image formed in the imaging plane is received by a receiving transducer and transferred into electrical signals. The apparatus also contains an ultrasound condensing device such as a lens, a mirror, or a combination of such elements. This condensing device forms an ultrasonic image of the wave-generating transducer in the aperture of the imaging device. Thus, an increased uniformity of the intensity distribution in the image plane and an increased image contrast for high-spatial frequency information are obtained.

Insonification apparatus for an ultrasound transmission system

Pulsed real-time B-scan ultrasonic method and apparatus are disclosed together with pulsed Doppler Ulrasonic method and apparatus. The B-scan apparatus includes a pulse operated transmitter and receiver operating at a first frequency, and the Doppler apparatus includes a pulse operated transmitter and receiver operating at a second frequency sufficiently far removed from the B-scan frequency to avoid interference therebetween. A synchronous pulse operation of the B-scan and Doppler systems is provided. The sysem includes a visual display means to which the receiver outputs are connected through a multiplexer operated to pass the B-scan receiver output to the visual display means whenever such B-scan output is present. The Doppler apparatus includes means for temporarily storing the Doppler receiver output, which stored Doppler signals subsequently are read out through the multiplexer to the visual display means between select lines of B-scan display. A simultaneous display of the B-scan image and a Doppler profile is provided when desired. A control stick unit, under one-hand control of the operator, is used to select the position of the line along which the Doppler profile is obtained and displayed. A cursor generator, under control stick control, is used to generate a cursor signal for display of a cursor along which the Doppler profile is displayed. The B-scan apparatus is operable with a normal or magnified display of a section of the object under investigation. Also, a reticle signal generator is included for t

Real-time ultrasonic B-scan imaging and Doppler profile display system

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Palo Alto, CA, United States of America

S David Ramsey, Jr