A Modular 3-Degree-of-Freedom Force Sensor for Robot-assisted Minimally Invasive Surgery Research

TL;DR

This paper introduces a modular, easy-to-manufacture 3-DoF force sensor for robot-assisted minimally invasive surgery, enabling high-quality force data collection with sufficient accuracy for delicate tissue manipulation tasks.

Contribution

The authors present a novel, open-source 3-DoF force sensor that simplifies integration and manufacturing while maintaining accurate force measurement suitable for RMIS applications.

Findings

Sensor range: ±5 N axial, ±3 N lateral.

RMSE below 0.15 N in all directions during tasks.

Achieved grip force RMSE of 0.156 N.

Abstract

Effective force modulation during tissue manipulation is important for ensuring safe robot-assisted minimally invasive surgery (RMIS). Strict requirements for in-vivo distal force sensing have led to prior sensor designs that trade off ease of manufacture and integration against force measurement accuracy along the tool axis. These limitations have made collecting high-quality 3-degree-of-freedom (3-DoF) bimanual force data in RMIS inaccessible to researchers. We present a modular and manufacturable 3-DoF force sensor that integrates easily with an existing RMIS tool. We achieve this by relaxing biocompatibility and sterilizability requirements while utilizing commercial load cells and common electromechanical fabrication techniques. The sensor has a range of +-5 N axially and +-3 N laterally with average root mean square errors(RMSEs) of below 0.15 N in all directions. During teleoperated mock tissue manipulation tasks, a pair of jaw-mounted sensors achieved average RMSEs of below 0.15 N in all directions. For grip force, it achieved an RMSE of 0.156 N. The sensor has sufficient accuracy within the range of forces found in delicate manipulation tasks, with potential use in bimanual haptic feedback and robotic force control. As an open-source design, the sensors can be adapted to suit additional robotic applications outside of RMIS.