ASA 127th Meeting M.I.T. 1994 June 6-10

2pBV10. Active cavitation detection of microbubble echocontrast agents in blood.

Vilma E. Huertas

Inder Raj S. Makin

E. Carr Everbach

Dept. of Eng., Swarthmore College, Swarthmore, PA 19081-1397

Apfel's active cavitation detector [Roy et al., J. Acoust. Soc. Am. 87, 2451--2458 (1990)] has been improved to allow quantification of microbubble activity in reconstituted human blood. One-microsecond-long 20-MHz tone bursts are scattered from microbubbles undergoing transient cavitation at the focus of a pulsed 1-MHz transducer. The host medium consists either of human red blood cells suspended in autologous plasma or platelet-rich plasma, with various concentrations of microbubble-based echocontrast agent present. The microbubble activity inferred from the backscattered tone bursts is compared to measured bioeffects (hemolysis, platelet aggregation) in order to determine the physical basis for cavitational damage of blood components. Current results as a function of system parameters will be presented. [Work supported by NSF MSS-9253777.]