Devices for assessing the size, shape, and topography of vessel lumens and hollow portions of organs are described. The devices are particularly adapted for determining the size, shape, topography, and compliance of the native heart valves to facilitate the later implantation of a prosthetic heart valve....http://www.google.es/patents/US8057396?utm_source=gb-gplus-sharePatente US8057396 - Device for assessing a cardiac valve