The goal of the Haptic Forceps project was to develop a haptic (force feedback) control device that surgeons would hold and manipulate to control the NeuroArm neurosurgery robot developed by Dr. Sutherland and MDA. An improvement over the older push-button interface, the Haptic Forceps would allow surgeons to feel the stiffness and texture of tissues as the robot grasped them. By mimicking this touch sensation with the same form factor (shape, size, and feel) of traditional forceps, we achieved improved sensing capability while simultaneously making it easier for surgeons to control the robot.

Key Features:
– Haptic (Force and Vibration) Touch Sense
– Improved Surgeon Awareness
– Intuitive Robot Control

Project Overview

The Haptic Forceps technology was created as a proof of concept for a surgical interface that provided force and vibration (haptic) feedback to a surgeon holding them. As the haptic system would be more complex and costly than the original push-button interface, our team was tasked with testing haptic technologies and quantifying their effect on surgeon performance. An undergraduate research student on the team, I tested and characterized the Forceps’ electromechanical system and assisted with the mechanical design of the Forceps.

Forceps Characterization

My main objective in characterizing the Forceps’ electromechanical system was to determine the correct actuator force needed to replicate what a surgeon would feel from traditional medical forceps. To accomplish this, I developed a lookup table that related a tip squeeze force sensed by the NeuroArm robot to an actuator voltage in the Forceps, such that the user feels the correct force at their fingertips. As a secondary objective, I also determined the Forceps’ physical bandwith, the range of vibration frequencies that the Forceps could accurately reproduce. Replicating vibrations between NeuroArm and the Forceps proved useful in reproducing a sense of texture if NeuroArm’s grip on tissue slips during surgery.

Mechanical Design

The key challenge in the mechanical design was to fit the Forceps’ computers, sensors, and actuators into a device approximately the size of a highlighter. My primary contribution was identifying the optimal placement for the voice coil actuator used in the design, balancing range of motion and actuation force. I also developed many of the secondary support structures within the Forceps for holding circuit boards and sensors. By the end of the project, we had two functional prototypes assembled and tested, which could transmit force accurately between them.

Publications

– Mechatronic Design of Haptic Forceps for Robotic Surgery (official)