| 摘要 |
An apparatus and method for direct measurement of the volume flow of fluids through a tube, using an interferometric transit time technique is disclosed. First and second transducers for producing and receiving waves which are capable of being modified by the flow of the fluid in the conduit are positioned so that the conduit is fully and evenly illuminated by the waves. The transducers are located with respect to the conduit so that there will be a component of fluid flow along the axis of the illuminating wave beam. Means are provided to first activate one transducer to transmit waves while the other is in a receive mode and thereafter to place the second transducer in a transmit mode while the first is switched to its receive mode. The received waves are converted to corresponding electric signals by the corresponding transducers, and these signals are periodically sampled and stored for comparison. The result of this comparison is an electric signal which is proportional to fluid flow and is to a high degree independent of flow profile, conduit geometry, and alignment of the conduit within the probe. The device is particularly useful in measuring the flow of blood through a vessel.
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