a prosthetic medical device is formed by the combination of a biological tissue a shape memory polymer structure . the biological tissue provides an in - situ physiological function of the device . the shape memory polymer provides a capability for minimizing the device profile during insertion and then deploying after placement into a memory shape that achieves suitable mechanical structure and stability within an anatomical lumen or cavity . this configuration may be applied to form various prosthetic devices including aortic , mitral , and tricuspid valves in the heart ; venous valves ; anti - reflux valves for the lower esophageal sphincter ; and other biological valve structures . alternatively , an entirely non - biologic implementation using only shape memory polymer - based structures may be used as a prosthetic valve device .