<title>Micro-strain gauge endoscopic tactile sensor using two sensing elements for tissue manipulation</title>

Abstract

Currently available commercial endoscopic graspers do not have any built-in sensors. Thus, the surgeon does not have any tactile feed-back to manipulate tissues safely. This paper reports on the design, fabrication and testing of a semiconductor micro-strain gauge endoscopic tactile sensor. This sensor consists of two semiconductor micro-strain gauge sensors which are positioned at the back face of an endoscopic grasper. It can measure the magnitude and the position of the applied force with only two sensing elements. The amplification system for the strain gauge is also designed and fabricated. It is shown that when a force is applied to the endoscopic grasper, the magnitude of the applied force can be visually seen in an LED device. The position of the applied force is obtained by combining the output from two insulated strain gauges. We have shown that the grasper operates in a wet environment. It exhibits high force sensitivity, large dynamic range, and good linearity. The sensor is integrated with a commercial endoscopic tool. The advantages and disadvantages of the system are also discussed.