Hand-Held Instrument with Integrated Parallel Mechanism for Active Tremor Compensation During Microsurgery.

Physiological hand tremor seriously influences the surgical instrument's tip positioning accuracy during microsurgery. To solve this problem, hand-held active tremor compensation instruments are developed to improve tip positioning accuracy during microsurgery. This paper presents the design and performance of a new hand-held instrument that aims to stabilize hand tremors and increase accuracy in microsurgery. The key components are a three degrees of freedom (DOF) integrated parallel manipulator and a high-performance inertial measurement unit (IMU). The IMU was developed to sense the 3-DOF motion of the instrument tip. A customized filter was applied to extract specific hand tremor motion. Then, the instrument was employed to generate the reverse motion simultaneously to reduce tremor motion. Experimental results show that the tremor compensation mechanism is effective. The average RMS reduction ratio of bench test is 56.5% that is a significant tremor reduction ratio. For hand-held test, it has an average RMS reduction ratio of 41.0%. Hence, it could reduce hand tremor magnitudes by 31.7% RMS in 2-DOF.