Dynamic ultrasonic visualization of blood vessels and flows
The stationary echo cancellation system has been designed on the basis of the properties of periodic filters using quartz delay lines. A level of stationary echo cancellation above 55 dB was achieved, which, when using an original detector of the phase of signals scattered in blood, permits real-time observation of blood flow velocity profiles. This, in turn, permits the internal diameter of a vessel (the degree of constriction) to be evaluated in the site under investigation.
References
F. E. BARBER, D. W. BAKER, A. W. C. NATION, D. E, STRANDNESS, J. M. REID, Ultrasonic duplex echo-Doppler scanner, IEEE Trans. On Biom. Engng., BME 21, 2 (1974).
W. BUSCHMAN, Ultrasonic imaging of arterial wall echoes, Ultrasound in Med. and Biol., 1, 33-43 (1975).
L. FILIPCZYŃSKI, R. HERCZYŃSKI, A. NOWICKI, T. POWAŁOWSKI, Blood flows: hemodynamics and ultrasonic Doppler measurement methods (in Polish), PWN, Warszawa – Poznań 1980.
L. FILIPCZYŃSKI, G. ŁYPACEWICZ, J. SAŁKOWSKI, T. WASZCZUK, Automatic eye visualization and ultrasonic intensity determination in focused beams by means of electrodynamic and capacitance methods, Proc. 2nd European Congress on Ultrasonic in Medicine, Munich 12-16 May, 1975; Excerpta Medica, Amsterdam 1975.