The high frequency testing of vascular grafts and vascular stents: influence of sample dimensions on maximum allowable frequency.

There are over four dozen companies developing new products for the lucrative vascular graft and vascular stent markets. We have been studying the procedures used to pre-test vascular grafts, vascular stents, and mock arteries into which vascular stents are placed, so that appropriate high frequency durability/fatigue studies can be done in as short a time as possible, but also in a manner in which the data are highly reliable and dependable. In the past, we have evaluated the testing of the natural frequency response of the grafts, mock arteries, and stents in order to determine the frequencies that can be used for long-term life testing. In this paper, we present experiments that evaluate how product geometry affects product frequency response at various loading pressures. Results show that changing the dimensions of the device to be tested such that less fluid has to be injected (in the case of hydrodynamically driven experiments) results in the ability to test these products at a higher frequency.