Evaluating manual control devices for those with tremor disability.

Tremor disabled subjects were tested in two dimensional tracking tasks. The subjects had action tremor due to various etiologies. Both continuous and discrete targets were used. Displacement sensing and force sensing joysticks were compared. The effect of filtering of the control signal was evaluated. Position and velocity control were compared. While individuals were found to benefit from various combinations of control setups, no single control modification or combination of modifications was beneficial to all. It remains necessary to adapt manual control interfaces to the needs of the individual disabled person. Most customizing can be implemented with software.