| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that, even if having a same blood flow rate, the pitches of probe sound are varied according to probes to be used. SOLUTION: This ultrasonic blood flowmeter determines the frequency of a transmission signal of a connected probe 4. A detection circuit 8 detects Doppler shift frequency component signal out of reflected ultrasonic waves received by the connected probe 4. When the frequency of the transmission signal of the probe 4 is a first frequency, the Doppler shift frequency component signal detected by the detection circuit is acoustically output. On the other hand, when the frequency of the transmission signal of the probe 4 is a second frequency which is lower than the first frequency, the frequency of the detected Doppler shift frequency component signal is multiplied by a frequency multiplication circuit and the frequency-multiplied Doppler shift frequency component signal is acoustically output. COPYRIGHT: (C)2008,JPO&INPIT
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