Method for detection of cavitations during medical application of high sonic energy

摘要

A method and apparatus are described for the detection of possible tissue injuries caused by cavitation during the medical application to a patient's body of high sonic energy which is generated extraneously by means of a sonic transducer for destruction of an element-for example a concretion-which is present in a target area. To detect the possible occurrence of cavitation the target area is acted upon by an acoustic test signal and a reception signal is generated from at least an initial reflection of the test signal. This signal is then examined by comparison with the test signal to detect the presence of an impedance jump leading to an attenuated reflection, so that a control signal may be generated upon detection of an impedance jump of this nature. Audible or visible warning signals may be engendered among others, and the sonic transducer may be deactivated if need be, by means of this control signal.