| 摘要 |
PROBLEM TO BE SOLVED: To stably measure the flow rate of blood and detect the generation of reverse flow and at the same time reduce the delay time of reverse flow recovery judgment in an ultrasonic doppler blood f lowmeter. SOLUTION: The ultrasonic doppler blood flowmeter comprises an ultrasonic probe, a cross detection section for outputting the frequency deviation of frequency in echo signals, a direction detection section for outputting an inverse direction output signal when the direction of a blood flow is reverse, a flow rate calculation section for calculating the flow rate of blood by a signal where the frequency deviation signal of echo signals is averaged for first specific time, an inverse flow judgment means 403 for detecting the inverse flow of blood by a signal where an inverse direction output signal is averaged for first specific time, an inverse flow recovery judgment means 404 for detecting recovery from the inverse flow of blood from a signal where the inverse direction output signal is averaged for shorter second specific time than the first specific time, a display section for displaying information on the flow rate of blood, and an inverse flow alarm means for giving an inverse flow alarm when the inverse flow judgment means detects the inverse flow of blood and cancelling the inverse flow alarm when the inverse flow recovery judgment means detects the inverse flow recovery of blood.
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