Biomechanical analysis of an accelerated fatigue test method for polymer valves

Jpn J Artif Organs 29(2), 489-495 A method for performing accelerated fatigue tests for polymer valves has not yet been established. We performed preliminary trials regarding an accelerated fatigue test on Jellyfish valve wherein the fracture pattern can be consistent with that obtained in an animal experiment. The influence of maximum load at valve closure as well as the influence of water temperature on the fracture mode of Jellyfish valve was specifically focused. When the value of maximum load at valve closure in the accelerated fatigue test was decreased to half as compared with that obtained in a mock loop under 105 bpm, the fracture mode was not consistent with that of the animal experiment, even if the water temperature was elevated from 40°C to 60°C. However, when the maximum load was decreased to quarter value in 60°C water, the fracture mode in the accelerated fatigue test was successfully consistent with that of the animal experiment. Therefore, it was confirmed that both maximum load at valve closure and water temperature were essential parameters for the accelerated fatigue test of polymer valves. In this case, following are recommended: maximum load at valve closure should be decreased, while water temperature should be elevated.