| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost ultrasonic diagnostic instrument having a pulse mode and a continuous wave doppler mode, and reduced in cost. SOLUTION: The instrument transmits an ultrasonic pulse and a continuous wave alternately from a plurality of ultrasonic vibrators and receives a reflected ultrasonic doppler signal from a subject. In the continuous wave doppler mode, a reception signal is divided into a common-mode component and an orthogonal component. Then quadrature detection, removal of a carrier frequency component comprised in the reception signal, and then, digital conversion is performed. After prescribed delay is given to each signal, phasing addition is performed. COPYRIGHT: (C)2005,JPO&NCIPI |
