PosterTemplateLargeJLP

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FLEXURE-BASED MANIPULATOR FOR ACTIVE HANDHELD
MICROSURGICAL INSTRUMENT David Y. Choi and
Cameron N. Riviere The Robotics Institute,
Carnegie Mellon University, Pittsburgh, PA USA
Need for tremor compensation
Flexure-based manipulator

• Tremor characteristics
• Roughly sinusoidal, 8-12 Hz
• 50 um p-p

Spherical flexure
Male Luer connector
Revolute flexures
Cavity for piezoelectric stack

• Tasks difficult or impossible
• Removal or retinal membrane 20 µm thick
• Intraocular cannulation of 100 um diameter vein

• Complexity 1 part
• Errors free of backlash and friction
• less sensitive to manufacturing error
• no assembly
• Cost 60 1.5 of the former cost

• How Micron works
• Handheld instrument with active tremor
  compensation for vitreoretinal surgery

Results
3 DOF Circle Tracking rmse 12.1 um
1 DOF Sinusoid Tracking rmse 6.5 um
Conventional manipulator infeasible
Handheld Result

• Three-degree-of-freedom (DOF)
• Parallel mechanism
• Actuated by piezoelectric stacks

Total range 52 reduction RMS amplitude 47
reduction

• Complexity gt30 parts
• Errors machining, assembly
• larger than tremor
• Cost 4000

Many parts of conventionally machined manipulator

• SUPPORTED BY
• NIH (grant no. 1 R01 EB000526)
• NSF (grant no. EEC-9731748)