| 摘要 |
PROBLEM TO BE SOLVED: To reduce transmission and reception of ultrasonic pulses for Doppler measurement to and from unnecessary scan lines which do not belong to a Doppler measurement region. SOLUTION: The maximum value of the number of scan lines is obtained (S3) where ultrasonic pulses are transmitted and received by switching the scan lines to avoid mutual interference of adjacent scan lines within a period of Doppler measurement pulse repeating frequency. The number of blocks is obtained by dividing the number of all scan lines in the Doppler measurement region by the maximum value (S4). All of the scan lines in the Doppler measurement region are evenly assigned to each block (S5). The frequency obtained by multiplying the number of the scan lines assigned to each block by the Doppler measurement pulse repeating frequency is controlled as a switching frequency for the scan lines (S6, S7). COPYRIGHT: (C)2008,JPO&INPIT |
