Fuzzy calibration of magnetometer in presence of surgical microscope

A method is presented for data-driven calibration of the magnetometer in an active handheld microsurgical instrument in the presence of a surgical microscope. The instrument is designed to provide tremor compensation during vitreoretinal microsurgery. An adaptive-network-based fuzzy inference system is used to generate a calibration based on data points collected at random locations throughout the workspace. Inputs to the model include the tilt angle and the twist angle about the long axis of the instrument, obtained from accelerometer readings, and the azimuth of the apparent magnetic north, obtained from the magnetometer readings. The model outputs the true azimuth angle of the instrument. Results from preliminary testing of the method are presented.