Micron: An Actively Stabilized Handheld Tool for Microsurgery

TLDR

The study presents a hand‑held actively stabilized tool designed to enhance accuracy in microsurgery and other precision manipulation tasks. The tool employs a 3‑DOF piezoelectric manipulator (400 µm range, 1 N force, >100 Hz bandwidth) and a high‑resolution optical position sensor (4 µm, 2000 Hz) controlled to attenuate hand tremor by at least 15 dB while preserving eye‑hand coordination. Testing with three eye surgeons and three non‑surgeons showed a 32–52 % reduction in position error across three manipulation tasks.

Abstract

We describe the design and performance of a hand-held actively stabilized tool to increase accuracy in micro-surgery or other precision manipulation. It removes involuntary motion such as tremor by actuating the tip to counteract the effect of the undesired handle motion. The key components are a three-degree-of-freedom piezoelectric manipulator that has 400 μm range of motion, 1 N force capability, and bandwidth over 100 Hz, and an optical position measurement subsystem that acquires the tool pose with 4 μm resolution at 2000 samples/s. A control system using these components attenuates hand motion by at least 15 dB (a fivefold reduction). By considering the effect of the frequency response of Micron on the human visual feedback loop, we have developed a filter that reduces unintentional motion, yet preserves intuitive eye-hand coordination. We evaluated the effectiveness of Micron by measuring the accuracy of the human/machine system in three simple manipulation tasks. Handheld testing by three eye surgeons and three non-surgeons showed a reduction in position error of between 32% and 52%, depending on the error metric.