Acoustical image reconstruction in parallel-processing analog electronic systems

Ultrafast cardiac-valve ultrasonic tomography requires parallel multichannel processing of received echoes. In parallel processing the level of secondary ’’ghost’’ images due to spatial undersampling is much higher than in slower series processors which use a selective field insonification. The paper describes a 20-channel moving-focus parallel-processing analog electronic system, which is realized in our laboratory. It is shown analytically that the secondary-image level is reduced and remains unchanged when the receiver angular aperture (aperture relative to distance) is limited and kept constant during the whole observation time.