Design and development of active endoscope using shape memory alloy actuators

Abstract

Minimally invasive surgery is well-accepted in the society because it involves lesser operative trauma for a patient than an equivalent invasive procedure. It causes less pain and scarring, faster recovery, and reduces the incidence of post-surgical complications. An endoscope is considered as one of the most powerful diagnostic and therapeutic tool for dealing abnormalities inside the body. This article aims at deciphering a solution to the problem of passive bending of conventional endoscopes by introducing a concept of active bending by using shape memory alloy (SMA) micro actuators. The developed prototype has many small segments connected to one another by a ball and socket joint, actuated independently which gives rigidity and high degree of manoeuvrability to the scope. The article proposes an algorithm for traversing the scope inside the body and addresses a very important issue of taking it out without causing any damage to the track. A graphical interface gives the practitioner a number of options to orient the scope [on the basis of three-dimensional (3D) discrete points reached by the tip and segment orientations based on camera image] and simultaneously shows a 3D view of orientation of the full scope.