| Popis: |
In order to evaluate the effects of shock waves passing through bone and to evaluate the amount of energy attenuation and its dependence on bone thickness and composition, the pelvic bones and femurs of two pigs were exposed to shock waves. These bones were brought into the acoustic field in an experimental Dornier lithotripter (XL1). Measurements were made at seven different sites and at various generator voltages (14 kV, 17 kV, 20 kV, and 23 kV). For registration of the pressure amplitude transmitted, a polyvinyl difluoride (PVDF) membrane hydrophone probe was used. Electrodes for measurement had generated at least 150 shock waves. A significant correlation between the pressure transmitted and the whole bone thickness (r = 0.87) was found, and this correlation can be described with an exponential equation. The energy attenuation primarily is influenced by the amount of cancellous bone (r = 0.74). The shock wave profile is not changed significantly with a bone thickness of less than 1 cm. |
