The in-vitro-fatique testing of stents is defined in the standard EN 14299 as a test under simulated vessel conditions with a load cycle number according to a life span of 10 years in vivo. The measuring instrument developed at the Testing Laboratory permits an accelerated examination with a test frequency of 100 cycles per second and leads to a test duration of approx. 45 days. The central point of the test set-up is the test chamber, in which the stent loading under simulated physiological conditions takes place. The demanded conditions, simulated by dynamic and static pressure loading, are applied simultaneously. A polyurethane (PUR) tube directly transmits the load directly onto the stent, which is in permanent contact with physiological saline solution. The temperature of the test chamber is kept isothermal at 37±1 °C. All test parameters are measured over the entire testing time. They are adjusted and logged by the controller. Fatigue examinations are possible for stents in the diameter range of 2,5-15 mm (balloon-expandable or self expanding).
	After completion of the fatigue testing a light-microscopical inspection of the stent condition is conducted. Additionally, selected stent areas are examined by scanning electron microscopy (SEM).