An Endoscopic Grasper Tool With Integrated Tactile Sensors for Use in Minimally Invasive Surgery

In this paper, we report on the design, testing, fabrication, and modeling of a semiconductor-based microstrain gauge endoscopic tactile sensor. This sensor is capable of measuring both the magnitude and the position of an applied load on a commercial endoscopic grasper tool. It consists of two microstrain gauge sensors, placed on the prototype endoscopic grasper. A light emitting diode device is used to visually see the intensity of the applied force. In total, 20 different force magnitudes for 7 different locations on the endoscopic grasper are tested experimentally. The range of force magnitude changes in the domain of 0.5 N to 10 N. The in-house electrical amplification system for the microstrain gauges is also designed, fabricated, and tested. The sensor is insulated and can operate safely in wet environments. The designed sensor assembly exhibits high force sensitivity, good linearity, and large dynamic range. A three-dimensional finite element modeling (FEM) is employed to predict the behavior of the designed system. Based on FEM results, there is a good agreement between these data the results obtained experimentally.