A High-Voltage Discharging System for Extracorporeal Shock-Wave Therapy

Abstract

Extracorporeal Shock wave therapy has applied by medical doctors on lithotripsy and orthopedics in replacing traditional surgery [1]. For generating shock waves, a high-voltage system of electrical mechanism is necessary to provide [2], and is designed with particular features in this study [3]. In order to build a high-voltage system for an extracorporeal shock wave therapy, some electrical circuits was specially designed and assembled by a charging capacitor system and a discharge control system. The components of the high-voltage system include a power supply, high-voltage resistors, capacitors, a spark gap, a triggering module, and two electrodes. Because the high-voltage power supply is the most decisive device, some electrical components were designed to be protected due to the electromagnetic interference associated with the high-voltage power supply. The high-voltage system can be applied to electromagnetic [4], electrohydraulic and piezolectric shock wave generators that produce shock waves. The details of materials and design methods used will be described. Control procedures for the designed shock wave therapy machine will be explained as flow charts. Schematic diagrams for all designed circuits and dimensions will be illustrated. Each single control procedure for the high-voltage system was validated by a time sequence and profiles of signals captured from an oscilloscope. It is noted that electromagnetic interferences associated with the high-voltage system have been reduced by 99% [5–7] by using well-shielded and optical devices such as optical fibers and infrared modules for controlling signals. Moreover, the mechanical and electrical properties of our designed shock wave generator have been measured. Finally, the positive peak pressure, negative peak pressure, and shock wave intensity were measured by using the pressure sensor of a PVDF membrane hydrophone [8].