| 摘要 |
PROBLEM TO BE SOLVED: To reduce burden at the time of observation of an HITS (High Intensity Transient Signal) and obtain appropriately data on the risk of thrombosis by computing power from signals received from a transmission and reception means, monitoring this power and detecting a prescribed momentary peak. SOLUTION: Signals received by an ultrasonic probe are sent to an orthogonal detector 10 and converted to a complex signal consisting of a real number portion and an imaginary number portion. Autocorrelation computation 12 is executed to this complex signal, averaging 14 is carried out to this complex signal, a phase 16 corresponding to speed information is computed 16 from the complex signal after averaging. The square of the real number portion in the complex signal and the square of the imaginary number are added, a square root is obtained for the added value and Doppler power is computed 18, and the Doppler power information obtained by averaging 20 this is sent to a selector 22 together with speed information. Here Doppler power information exceeding a threshold value is extracted as an HITS, and the number of times the HITS was judged is counted 24 and displayed on a display 28. |
