| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic flow measurement system for photographing the blood flow of a human body utilizing the mutual correlation of base band data capable of saving a memory space and reducing calculation resources. SOLUTION: This ultrasonic flow measurement system 10 converts respective plural reflection sample value groups from a scatterer to base band complex data values and judges a speed only from two lag samples. A mutual correlation function leads a first mutual correlation value between the first set of complex data value an the first set of the complex data value, and a second mutual correlation function leads a second mutual correlation value between the first set of the complex data value and the third set of the complex data value. A local oscillator 16 indicates the change rate of a phase per sample time and a processor leads the speed of an ultrasonic scatterer. Another linear function is established by the change rate of the phase of local oscillation signals, the time for generating the maximum value of the mutual correlation function is identified by the crossing of the two linear functions, and thus, the speed of the scatterer is led. |
