| 摘要 |
An ultrasonic blood flow velocimeter for measuring the velocity of blood flowing in an artery or vein beneath the skin of a patient, by insonating the tissue with ultrasonic energy, receiving doppler-shifted signals reflected by the blood and processing the signals to determine blood velocity. The signal processing and calculations result in an accurate measure of velocity which is independent of the angle between the probe and the blood flow. This gives more accurate results than other ultrasonic methods which approximate results because of angle dependency and the fact that in general this angle is unknown. The invention can also detect and discriminate between forward and reverse flows, even when they occur simultaneously, as in the case of insonating an artery and vein with opposite flows. The invention can also measure peak flow velocity, though efficient time domain processing of signals.
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