The purpose of this work is to develop a wideband, quantitative shock wave hydrophone made of the piezoelectric material polyvinylidene difluoride (PVDF). The novel aspects of this device include a low-cost disposable hydrophone element to significantly reduce the per-shot costs, and a self- monitoring system that informs the user when the hydrophone element has lost a specified accuracy and should be replaced. These hydrophones will be designed to fulfill the requirements for accurate, wideband measurement of lithotripter fields, suitable for quantitative biophysical research or Food and Drug Administration submissions. The disposable feature of the hydrophone system will make it cost effective for research, quality assurance and regulatory submissions. The Phase I portion of the project will focus on: l) investigating the effect of shock wave exposure on hydrophone elements; 2) developing the wideband preamplifier and hydrophone monitoring systems; 3) refining the means for rapid, reliable electrical connection to the disposable hydrophone elements; and 4) investigating low-cost fabrication techniques for the disposable elements. When fully developed under Phases II and III, the Disposable Lithotripsy Hydrophone will represent a new standard reference for the measurement and evaluation of lithotripsy systems, applicable to clinical quality assurance and lithotripter inter-comparison.
