1. Force Feedback of Dual Force-Sensing Instrument for Retinal Microsurgery Computer Integrated Surgery II - Spring, 2013 Woo Yang, Seo-Im Hong, Can Wang Mentors: Dr. Iulian Iordachita, Xingchi He, Dr. Russell Taylor
Introduction
Retinal microsurgery is one of the most challenging surgeries due to limited workspace and because it requires delicate movements.
The Eye-Robot is a cooperative control robot being developed with the goal of assisting surgeries to make it not only efficient but also safer.
There are two points of contact with the eye when inserting a surgical tool: the retina and the sclera.
Novel surgical instrument measures accurate forces at these sites but the problem is real-time feedback of these forces during the surgery.
Close up of the second generation eye phantom
Results and Outcome
We asked a few experienced eye surgeons to test out various sorbothane and rubber of hardness ranging from 30 OO to 30 A. It was determined 50 OO was closest.
The glitchy robot arm haptic feedback mode resulted in the tool being rammed into the eye phantom and destroyed the tool.
However from the data, we are able to conclude other methods of feedback lowered the amount of force used in experiments.
Vibrotactile and auditory feedback yield similar results, which would leave the usage will be up to user preference.
IRB for human subject testing was submitted 3/15/2013 but is yet to be approved.
Problem
Safe amount of force to be applied on the retina is < 7 mN (below human perception threshold), but robotic systems can help.
The robot will read accurate forces and, with the proper feedback system, will alert the surgeon below and above safe thresholds.
There are many different available methods of force feedback: auditory, vibrotactile, and robot haptic. Which one will minimize the amount of forces experienced by the eye?
Solution
Future Work
To determine which feedback method is the most ideal, we had to set up an experiment that mimics an eye surgery. This involved developing an eye phantom. The experiment involves peeling a piece of tape from inside the phantom to mimic membrane peeling.
In addition, the existing robot didn’t integrate vibrotactile mode which we implemented by interfacing the Arduino microcontroller with a small motor attached to the pedal
Glitches from the robot haptic feedback should be worked out to prevent future mishaps.
More fine-tuned vibrotactile motor could be incorporated to experiment with different amplitudes and faster refresh rate.
Human subject testing for larger data collection.
Citation
X. He et al. A Novel Dual Force Sensing Instrument with Cooperative Robotic Assistant for Vitreoretinal Surgery
I. Iordachita et al. A sub-millimetric, 0.25 mN resolution fully integrated fiber-optic force-sensing tool for retinal microsurgery. Int J CARS (2009) 4:383–390
Citation
Core NSF CISST/ERC
Thank you to our professor Dr. Taylor, our mentors Dr. Iordachita and Xingchi He, and special thanks to Marcin Balicki
Left: Eye robot experiment
Right: Engagement pedal with Arduino Microcontroller
Engineering Research Center for Computer Integrated Surgical Systems and Technology