Wrist/Arm support to assist in fine motor control for essential tremor patients

Biomed Sci Instrum. 2014:50:37-40.

Abstract

Steady-state hand tremors tend to exhibit simple harmonic motion associated with frequencies of 2-11 Hz, and maximum amplitudes of 7.8 inches. Tremors often present difficulties in applications dependent on fine motor control. A wrist/arm constraint is being designed to minimize the difficulty of performing fine motor functions via amplitude and frequency reduction of the hand tremor. Tremor amplitude and frequency reduction can be achieved by utilizing mechanical dampers as well as viscoelastic materials to cradle the wrist and hand. The goal of this project is to design a mechanical, table-mounted wrist cradle with a damped natural frequency lower than the tremor frequency. This project is being designed for a specific person with tremor frequency of 5-6 Hz and peak-to-peak amplitude of 2.5 inches. These specifications will enable the user to touch a 1 inch by 1 inch icon on a touchscreen tablet device. The design team for this project consisted of senior Mechanical Engineering students from the University of Wyoming. Funding for this project is provided by NSF-BME-RAPD Grant 0962380.