| 摘要 |
A portable apparatus for determining the degree of occlusion in a blood vessel. The apparatus includes a transmitter for producing an ultrasonic signal, a first probe for directing the ultrasonic signal to a first location in a blood vessel and a second probe for directing an ultrasonic signal to a second location in the blood vessel. A first receiver receives the ultrasonic signal after return from contact of blood flowing in the blood vessel at the first location and produces a first received signal representative thereof. A second receiver receives the ultrasonic signal after returning from contact with blood vessel at the second location and produces a second received signal representative thereof. A difference measuring circuit receives the first and second received signals and produces a difference signal representative of the difference between the first and second received signals so that a difference in blood flow velocity at the first and second locations can be determined.
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