Ultrasonic digital interferometer for investigation of blood clotting.

The digital ultrasonic fixed path interferometer designed for testing small amounts of sample was used for the investigation of whole blood coagulation, retraction and clot melting processes. The ultrasound velocity and absorption are determined from the characteristics of an acoustic resonator consisting of an emitter, a column of liquid to be tested and a receiver. The measuring accuracy of the ultrasound velocity is 0.1 ms-1, resolution--0.01 ms-1; the absorption measuring error does not exceed 10%. The device operates automatically giving analogue signals in the output for the recorder and discrete ones for the tape puncher to process the results obtained by computer. This permits employment of the interferometer in complex investigation systems. The whole blood clotting characteristics obtained provide new information which correlates with the results of some biological tests.