Thomas A. Shoup

Ultrasonic imaging systems

The authors explain the workings of a modern phase-array imaging system and present examples of the technical advances that have helped make such systems possible. A cardiac imaging system will provide images using transducers from 2.5 to 7.5 MHz, make simultaneous Doppler measurements of blood velocity, including color flow, contain analysis software for making measurements on screen, and support a number of peripherals. Technical advances that have made this possible include the ability to make higher frequency phased-array transducers, new piezoelectric materials, advances in signal processing, and software embedded in the systems. The electronic advances include faster and more dense memories, high-speed but low-power logic, the ability to make gate arrays at reasonable cost, surface-mounted packages and improvements in hard-copy devices and video recording technology.<<ETX>>

Techniques for calculating ultrasonic integrated backscatter using frequency or time domain techniques

Apparatus for deriving signals indicating a condition of tissue within an area by launching spaced supersonic pulses into a body under examination and detecting the power of supersonic waves scattered from locations along a plurality of known paths. Gain control elements are provided for compensating for changes in amplitude of the scattered supersonic waves resulting from their passage through blood or tissue, the increased attenuation with frequency of the spectrum of the launched pulses and the focussing of the launched pulses. Compensation for ring-down and the attenuation of the chest wall is also provided.