Application of Shape Memory Alloys in Artificial Sphincters

Abstract

This paper describes the development of a shape memory alloy (SMA) actuator as an artificial sphincter. The artificial sphincter is expected to enable the active bowel movement of patients without the function due to inborn intestinal atresia or medical operations of an artificial anus. The actuator has the functions of a valve; keeping the artificial anus closed at the body temperature and opening it by heating the SMAs. Investigations on thermomechanical properties of the actuator have been carried out. The actuator has also been subjected to clinical tests on animals, and exhibits complete functions of an artificial sphincter.