Experimental test of MR fluid based tactile device for minimally invasive surgery

Abstract

Recently, it is very popular in modern medical industry to adopt robotic technology such as robotic minimally invasive surgery (RMIS). Compared with open surgery, the RMIS needs the robot to perform surgery through the usage of long surgical instruments that are inserted through incision points. This causes the surgeon not to feel viscosity and stiffness of the tissue or organ. So, for the tactile recognition of human organ in RMIS, this work proposes a novel tactile device that incorporates with magnetorheological (MR) fluid. The MR fluid is fully contained by diaphragm and several pins. By applying different magnetic field, the operator can feel different force from the proposed tactile device. In order to generate required force from the device, the repulsive force of human body is firstly measured as reference data and an appropriate size of tactile device is designed. Pins attached with the diaphragm are controlled by shape-memory-alloy (SMA). Thus, the proposed tactile device can realize repulsive force and shape of organ. It has been demonstrated via experiment whether the measured force can be achieved by applying proper control input current. In addition, psychophysical experiments are conducted to evaluate performance on the tactile rendering of the proposed tactile device. From these results, the practical feasibility of the tactile device is verified.