| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic system for analog/digital-converting and processing higher harmonic components in a large dynamic range, and to provide a processing method therefor. SOLUTION: The ultrasonic diagnostic system comprises: a drive transmission circuit 12 for driving a vibrator 15 which transmits and receives ultrasonic waves; a preamplifier 16 for amplifying reception signals in which the ultrasonic waves by the drive are reflected, received by the vibrator and converted to electric signals; a nonlinear compression circuit 17 for performing compression of a larger compression rate as the amplitude of the reception signals outputted from the amplifier is smaller corresponding to the amplitude; an analog/digital conversion circuit 18 for quantizing the output amplitude of the nonlinear compression circuit at equal intervals; a nonlinear expansion circuit 19 for restoring the output amplitude of the digital output on the basis of the nonlinear coefficient of each level; a phasing addition circuit 22 for aligning the delay phase of the output; a signal processing circuit 23 for selectively digital-processing the higher harmonic components of the output, extracting image signals and outputting the scanning line of two-dimensional images; and a display device 24 for image-displaying the output of the signal processing circuit. COPYRIGHT: (C)2006,JPO&NCIPI
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