Measurement of Shock Wave Pressure Distribution of Extracorporeal Shock Wave Lithotripter Using Pressure-Sensitive Paper : Practical Usefulness and Limitations

A new method for evaluating shock wave pressure distribution of extracorporeal shock wave lithotripters, using pressure-sensitive paper has been developed. It is a simple method to visualize the shock wave pressure distribution and has a better spatial resolution than the hydrophone. The pressure-sensitive paper can be used to visually detect whether the focal point is on the correct position, and to detect changes of pressure distribution. Additionally, the relationship between lithotripter power and integrated density as a new evaluating value shows linearity. Therefore, this method is useful for quality assurance of lithotripters at hospitals.