The construction of an inexpensive 1 mm diameter 10 MHz single crystal catheter tip Doppler ultrasound probe for measuring blood velocities in fetal vessels is described. A simple bridge circuit which enables single crystal transducers to be used is also described.
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2.
WellsP. N. T., Biomedical Ultrasonics, pp. 358–363 (Academic Press, New York, 1977).
3.
ReidJ. M.DavisD. L.RickettsH. J.SpencerM. P., A New Doppler Flowmeter System and Its Operation with Catheter Mounted Transducers, in Cardiovascular Applications of Ultrasound, RenemanR. S., ed. pp. 183–192 (North Holland, Amsterdam, 1974).
4.
GoughJ. D.PooreE. R., Doppler Flowmeters in the Study of Foetal Breathing, in Doppler Ultrasound in the Study of the Central and Peripheral Circulation. WoodcockJ. P.SequeiraR. F., eds., Chapter 5 (University of Bristol Press, Bristol, England, 1978).
