Fiber optics tactile array probe for tissue palpation during minimally invasive surgery

This paper presents a novel fiber optic tactile probe designed for tissue palpation during minimally invasive surgery (MIS). The probe consists of 3×4 tactile sensing elements at 2.6mm spacing with a dimension of 12×18×8 mm³ allowing its application via a 25mm surgical port. Each tactile element converts the applied pressure values into a circular image pattern. The image patterns of all the sensing elements are captured by a camera attached at the proximal end of the sensor system. Processing the intensity and the area of these circular patterns allows the computation of the applied pressure across the sensing array. Validation tests show that each sensing element of the tactile probe can measure forces from 0 to 1N with a resolution of 0.05 N. The proposed sensing concept is low cost, lightweight, sterilizable, easy to be miniaturized and compatible for magnetic resonance (MR) environments. Experiments using the developed sensor for tissue abnormality detection were conducted. Results show that the proposed tactile probe can accurately and effectively detect nodules embedded inside soft tissue, demonstrating the promising application of this probe for surgical palpation during MIS.