An active force controlled laparoscopic grasper by using a smart material actuation

The excessive grasper force may lead to irrevocable damage to the tissue in minimally invasive surgery. This study focuses on grasping mechanism of a laparoscopic surgery tool in order to control the grasping force. First, the dynamics of grasping mechanism of a conventional laparoscopic grasper is investigated using analytical and experimental methods. Then, a smart laparoscopic surgery tool is designed using the shape memory alloy wire with a bias spring. The grasper force is controlled through the actuator by different type of controllers and performance of the controllers are compared. Closed-loop dynamics of the grasper mechanism is achieved with 3.34% overshoot and zero steady state error.