Inder Raj S. Makin
E. Carr Everbach
Dept. of Eng., Swarthmore College, Swarthmore, PA 19081-1397
Ultrasonic angioplasty devices awaiting FDA approval are being developed for the removal of atheromatous plaque in peripheral and coronary arteries [abstract, O. K. Colliou and E. C. Everbach, J. Acoust. Soc. Am. 93, 2330 (1993)]. This talk presents the results of work in progress on characterizing the acoustic field due to a vibrating ultrasonic catheter wire (MedSonic, Inc., New York), which is a second-generation device with a titanium spherical tip at its end. Changes in the radiation characteristics of the system operating at 22.2 kHz (cw) will be discussed, based on varying the system parameters. Results will be presented from wires with different ball-tip diameters, different driver intensity settings, and varying viscosities of damping fluid in the wire sheath. By determining the acoustic field of the device, the probable regions of cavitational activity responsible for the bioeffects observed clinically can be identified. [Work supported by NSF MSS-9253777.]