A miniature 3-axis distal force sensor for tissue palpation during minimally invasive surgery

This paper describes the design and development of a miniature 3-axis distal force sensor which can be applied in tissue palpation during minimally invasive surgery (MIS). The sensing principle is based on resistive sensing method that utilizes gauges to measure the strain of a flexible platform when exposed to a force. A novel tripod structure is designed and optimized as the flexible platform, it can generate enough strain to determine the magnitude and direction of 3 orthogonal force components (F_x, F_y, and F_z). The sensor prototype described in this paper can perform force measurement in axial and radial directions with working ranges of 3.0 N and 1.5 N, and the resolutions are 5% and 1% respectively. It is compatible with MIS instruments and can be used to perform tissue palpation.