Development and three-dimensional modelling of a biological-tissue grasper tool equipped with a tactile sensor

New surgical procedures, such as minimally invasive surgeries, separate the surgeons hands from the site of an operation. As a result, the surgeons perception of touch is limited to his/her visual abilities fed back from a video camera located at the end of an endoscope. To compensate for this restriction, this study investigates the design, fabrication, testing, and mathematical modelling of an endoscopic grasper tool in which a polyvinylidene fluoride (PVDF) tactile sensor is incorporated. The entire surface of the grasper jaw is active and can be utilized as a means of detecting the magnitude and application point of the applied force. This is in contrast to array-type tactile sensors, in which the areas located between the adjacent sensing elements are inactive. The sensor assembly consists of three distinct layers. The lower layer is made of Plexiglas, while the upper layer is made from micromachined silicon. PVDF film is placed between the upper and lower layers and forms the middle layer. Three-dimensional finite element modelling is used to analyze the performance of the designed system. Good correspondence is obtained between the experimental data and the modelling predictions.