(Received November 12, 1997; accepted for publication February 4, 1998)
In order to define the safety limit of the medical ultrasound equipment and to study the ultrasonic bioeffects, ultrasound exposure microscopic system (UEMS) was developed in our laboratory. We intended to observe the tissue damage caused by ultrasound exposure in real time. The change of size and shape of the cattle red blood cells was investigated experimentally with UEMS. It was observed that, at a driving frequency of 2.2 MHz, when the ultrasound intensity ISPTP was 28.4 W/cm2, the change of shape of the cattle red blood cells, due to the ultrasound exposure, occurred after 30 min of exposure. The change of size of the cattle red blood cells was investigated with a Coulter counter. The results, indicated that the size of the red blood cells after exposure to ultrasound was smaller than before exposure. Moreover, the results also indicated that, there was a tendency of the red blood cells to decrease in size after the ultrasound exposure when the ultrasound intensity was increased. At the two driving frequencies of 2.2 MHz and 0.55 MHz, in this study, the size of the cattle red blood cells decreased when the ultrasound intensities were increased.
KEYWORDS:ultrasound exposure microscopic system (UEMS), ultrasound exposure, ultrasound intensity, red blood cells, damage, real time