Electromagnetic tracker for active handheld robotic systems

Abstract

We describe the development of the In-Loop Electromagnetic Tracker (ILEMT), designed to meet the demanding latency and resolution requirements for active stabilization of hand motion during precision manipulations such as microsurgery. The prototype surpasses the fastest commercial EM trackers by > 4× in root bandwidth/resolution and 2× in latency. The use of two widely spaced carrier frequencies (e.g., 300 Hz and 10 kHz) enables a particularly simple way of reducing the eddy-current interference caused by nonferrous metals present in the workspace. Previously, metal compatibility has only been achieved at a large cost to measurement speed.

Robotic Retinal Surgery

“…The Micron uses a 6-DoF Stewart-platform (a.k.a., hexapod) parallel mechanism driven by piezoelectric motors. The motion of the handle is tracked (e.g., optically [126] or electromagnetically [124,125]) using an external system. The control system tries to extract the intentional motion of the operator and to cancel out all unintentional motion, including the tremor of the operator's hand.…”