Abstract

A hand control capable of suppressing tremors and other unwanted vibrations is disclosed which incorporates viscous damping in two degrees of freedom to mechanically filter the forces applied by the user's hand. To suppress pathological intention tremors, the damping characteristics are chosen so as to selectively reduce the amplitude of movements at or above about 3 Hertz. The hand control includes a chamber filled with a viscous fluid, a position-sensing actuator assembly and a damping element connected to the actuator and disposed within the chamber to suppress involuntary movements of the actuator. The volume of the chamber, size of the damping element and viscosity of the fluid are chosen to achieve a damping constant of about 2 to 20 lbf-sec/ft., preferably from about 5 to about 15 lbf-sec/ft. The viscous fluid is preferably a silicone oil having a viscosity of about 300,000 to about 900,000 cstokes.

Other References

• Rosen, et al., Proceedings--1979 International Conference on Rehabilitation Engineering, "A Damped Joystick: Adaptive Control for the Tremor-Disabled," pp. 74-79, 1979
• Laffey "The Use of a Mechanically Damped Joystick as a Means of Reducing Intention Tremor," pp. 1-75, 1985