| 摘要 |
PROBLEM TO BE SOLVED: To enable a correct ultrasonic image of moving tissue to be obtained using an adaptive clutter filter together with a sequence of designed pulses. SOLUTION: This filtering is configured so that low power pulses are scattered among high power pulses to continuously vary the characteristics of an adaptive filter harmonizing with reception of echoes of respective pulses. The threshold of the filter is set to a high threshold level upon reception of high power pulses so as to enable detection of non-tissue, and similarly a high threshold level is set upon reception of echoes from low power pulses so as to enable detection of tissue. Parameters of transmitted signals variable in addition to or instead of the above properties can include envelope shape, basic frequency, duration of pulse, size of transmission packet, frequency of pulse repetition, and transmission line density. COPYRIGHT: (C)2004,JPO&NCIPI |
