In the past ten years, extracorporeal shock waves have been successfully used in orthopedics. The idea of shock wave therapy is the stimulation of a healing process. Electrohydraulic shock wave therapy provides higher energy density flux than electromagnetic and piezoelectric types. But electrohydraulic shock wave generators are less stable than the other two types because of electrode erosion. In this study, a shock wave generator with a controllable spark gap system has been designed in order to give steady output pressures by automatic adjustment of the electrode gap. An ellipsoidal shock wave reflector is equipped with two AC servo motors with drivers. The motor driver actuates the associated motor which is connected to an electrode base by a belt. On a designed image feedback system, a CCD camera is used as the image detection tool to measure the electrode gap. Experimental results show the coincidence of the second focus of the shock wave reflector with the gas-dynamic focus. Moreover, measurements of focused pressure and energy intensity with PCB and PVDF pressure sensors and tests of stone fragmentation efficiency have been carried out to evaluate the performance of the newly designed shock wave generator with a gap-adjusted system and an image feedback system. It is found that the designed electrohydraulic shock wave generator is stable and efficient in pressure output with a low cost of electrodes.
5062Low- level confocal dual-pulse electrohydraulic shock wave therapy accompanied by tissue plasminogen activator and microbubbles administration for intracranial arterial recanalization