An ultrasonic pulsed Doppler system for measuring blood flow in small vessels.

tem for measuring blood Jaw in small vessels. J. Appl. Physiol. 37 (4): 626-629. 1974.-A new system has been developed for the measurement of blood flow in small vessels, l-5 mm in diameter. The transducer may be used in both acute studies where the vessel is directly exposed and in chronic studies where the transducer is surgically implanted around the vessel and flow measurements re-corded after the experimental animal has fully recovered from the surgical procedure. A ZO-MHz directional pulsed Doppler ultra-sonic flowmeter is used to drive a single piezoelectrical crystal, mounted on a small lightweight cuff-type probe. A unique trans-former coupling system allows the chronic implantation of flow probes leaving no wires protruding through the skin. Initial evaluation of the system on coronary arteries in acute and chronic dog studies shows good stability and linearity. coronary artery flow; chronic flow probe; flowmeter; laminar