Experimental study of effects of protecting cover layers for medical underwater shock waves

We visualized and analyzed effects of protecting cover layers during medical application of underwater shock waves. Shock waves can be generated by several methods. In this research, we used short pulse underwater discharges to produce tuned underwater shock waves
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. A magnetic pulse compression circuit (MPC) was used as energy source
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. Using MPC, we were able to produce nanosecond order pulse discharges with short rise times to generate controllable shock waves. For pressure measurements, fiber optic probe hydrophone was used. Shadowgraph high speed time-resolved technique was used for flow visualization. Natural latex, polyurethane, and Teflon were examined as cover layers. We compared these materials based on pressure measurement and flow visualization results, as well as theoretical analysis. The analyses were carried out based on the layers' acoustic impedance and attenuation rate. The results are important and applicable during medical applications.