ABSTRACT
Accuracy in micromanipulation tasks is limited and it is important to identify various factors affecting it. This paper studies the effect of visual magnification, speed and handedness to micromanipulation accuracy using microscope and LCD screen for feedback. Magnification of visual feedback increases the accuracy, but large magnification does not provide further improvement beyond 16x. Further, we observed a trade off between speed and accuracy in tracing a circular path, i.e. faster speed reduces the speed control ability of the hand. Finally, dominant/non-dominant hand is found to affect accuracy in motion.
Subject(s)
Feedback, Sensory/physiology , Micromanipulation/methods , Biomechanical Phenomena , Biomedical Engineering , Female , Hand , Humans , Male , Microsurgery/methods , Optical Phenomena , Task Performance and AnalysisABSTRACT
While tremor has been studied extensively, the investigations thus far do not give detailed information on how the accuracy necessary for micromanipulations is affected while performing tasks in microsurgery and the life sciences. This paper systematically studies the effects of visual feedback, posture and grip force on the trial error and tremor intensity of subjects holding a forceps-like object to perform a pointing task. Results indicate that: (i) Arm support improves accuracy in tasks requiring fine manipulation and reduces tremor intensity in the 2-8 Hz region, but hand support does not provide the same effect; hence freedom of wrist movement can be retained without a significant increase in trial error. (ii) Magnification of up to x10 is critical to carry out accurate micromanipulations, but beyond that level, magnification is not the most important factor. (iii) While an appropriate grip force must be learned in order to grasp micro-objects, such as a needle, without damaging them, the level of grip force applied does not affect the endpoint accuracy.
