Analysis of active handrest control methods

Abstract

People use fixed handrests to complete routine dexterous activities such as providing a signature or making a sketch. Because the hand's workspace for very fine motions is limited, we have developed an Active Handrest that extends a user's dexterous workspace while providing ergonomic support. Our current Active Handrest prototype is a planar, computer controlled support for the user's hand and wrist that allows complete control over a grasped tool. The device determines handrest motions by interpreting isometric (force) input from the user's wrist, isotonic (position) input from a grasped manipulandum, or a blend of both inputs. Circle tracing experiments measuring task precision and completion time were conducted to investigate each control mode under various velocity limits for both experienced and novice users. © 2010 Springer-Verlag.