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This is a research in active instruments for enhanced accuracy in
microsurgery. The aim is to make accuracy enhancement as transparent to
the surgeon as possible. Rather than using a robotic arm, we have taken
the novel approach of developing a handheld instrument that senses its own
movement, distinguishes between desired and undesired motion, and deflects
its tip to perform active compensation of the undesired component. Problem Definition and Implications
Involuntary hand movement of healthy human beings include: 1.
Physiological Tremor – roughly sinusoidal, up to 50 mm
p-p, 8-12 Hz 2.
Non-tremulous errors – Drift, jerk etc., aperoidic, usually > tremor
These erroneous hand movements restrict the types of microsurgical procedures that are feasible, and hinder the quality of those that are performed. There is some amount of consensus among the microsurgeons on the need for tool tip positioning accuracy to be approaching
10
mm. Technical Challenges
The major technical challenges of implementing active error
compensation in a handheld instrument are threefold: 1)
Accuracy requirement – mm-level
precision for sensing, filtering, and manipulator sub-systems 2)
Real-time issue – Phase shift (time delay) between input and output
< 1 sampling cycle 3) Miniaturization of components to be fitted in a handheld device |
