Characterization of the mitral valve using accelerated wear testing

There is a fundamental need for a better kind of long-term testing for artificial heart valves along with a biologically equivalent artificial mitral valve. Accelerated wear testing has been used for a long period of time in the engineering field to test the failure modes of materials and devices, but has not been widely accepted in the medical device area. The mitral valve is difficult to get to and therefore little is known about the leaflet motion. The lab has obtained a closed-system, compact, accelerated wear testing apparatus designed for aortic valves, and nothing is known about the device. The lab deals exclusively with mitral valves. The objective of this study is to characterize and fully understand this accelerated wear testing apparatus, to modify it to run with mitral valves and to define the mitral valve motion using pressure waveforms and leaflet motion. This was achieved by calibrating and verifying the device using an aortic valve with a known pressure curve. The device was then modified to fit mitral valves and the motor motion was measured to characterize the movement of the apparatus. A pressure waveform was then obtained for the mitral valve. Images of the mitral valve were obtained for these pressures and orifice area was calculated. This information gives a clear understanding about the design and function of the device and of the mitral valve.