HEMOLYSIS OF 40-PERCENT HEMATOCRIT, ALBUNEX(R)-SUPPLEMENTED HUMAN ERYTHROCYTES BY PULSED ULTRASOUND - FREQUENCY, ACOUSTIC, PRESSURE AND PULSE LENGTH DEPENDENCE

The dependence of hemolysis produced by pulsed ultrasound on ultrasoun d frequency, acoustic pressure and pulse length was explored, Human er ythrocytes (40% hematocrit; in Albunex(R)-supplemented autologous plas ma) were exposed (60 s) to 20 or 200 mu s pulses of ultrasound at freq uencies of 1.02, 2.24 or 3.46 MHz and at peak negative pressures [P-] ranging from 0.0 to similar to 3.0, MPa in 0.5 MPa increments, The dut y factor was 0.01. At each frequency, hemolysis increased with increas ing acoustic pressure and depended weakly on pulse duration, At relati vely high acoustic pressures, hemolysis depended strongly on ultrasoun d frequency; at lower pressures, the frequency dependence was weaker, The potential clinical significance of ultrasonic hemolysis is discuss ed. (C) 1997 World Federation for Ultrasound in Medicine & Biology.