A study of a hand-held instrument's angular motion due to physiological tremor in micromanipulation tasks.

Angular motion of a hand-held instrument due to physiological tremor during micromanipulation tasks was recorded with a six degree-of-freedom accelerometer-based sensing unit placed in the instrument. Methods to get angular velocities and angular accelerations from the acceleration readings of accelerators in the sensing unit are described. Statistics of angular velocity and angular acceleration of the instrument due to the tremor obtained from ten normal subjects are reported. Assumption of very small tremor angular velocities in micromanipulation tasks to calculate tremor angular accelerations analytically is validated.