Towards a modified consumer haptic device for robotic-assisted fine-motor repetitive motion training

Abstract

Purpose. To develop, test and evaluate affordable haptic technology to provide robotic-assisted repetitive motion fine-motor training.

Methods. A haptic computer/user interface was modified by adding a pantograph to hold a pen and to increase the haptic workspace. Custom software moves a pen attached to the device through prescribed three-dimensional (3D) stroke sequences to create two-dimensional glyphs. The pen's position is recorded in 3D coordinates at 1 kHz. Twenty-one healthy child volunteers were taught a standard handwriting curriculum in a group setting, two times per week for 45–60 min each session over 8 wks. The curriculum was supplemented by the device under the supervision of occupational therapy students. Outcomes were measured using the Evaluation Tool of Children's Handwriting (ETCH), and the Beery-Buktenica Developmental Test of visual-motor integration.

Results. Word legibility made significant gains on near point copying task (p = 0.04; effect size = 0.95). Letter legibility made no significant improvement. One healthy volunteer with illegible handwriting improved significantly on 8 of 14 ETCH measures. The children found the device engaging, but made several recommendations to redesign the pantograph and scribing movements.

Conclusions. A consumer haptic device can be modified for robotic-assisted repetitive motion training for children. The device is affordable, portable, and engaging. It is safe for healthy volunteers. Objective time-stamped data offer the potential for telerehabilitation between a remote therapist and the school or home.

Keywords:

• Rehabilitation
• motor processes
• handwriting
• robotics
• telerehabilitation
• sensory and motor testing

Acknowledgements

Lynn Gerber, MD, at George Mason University provided clinical rehabilitation advice. Kevin Tuer, PhD, PEng, currently at Communitech, Canada, provided early inspiration, guidance and PHANTOM Omni programming for the CompuWrite summer camp pre-pilot evaluation. Sidney Johnson, MS, OTA, Zoran Duric, PhD, and others at George Mason University also worked on the software platform of the haptic handwriting in the pre-pilot study. Kathleen Allgood, OT, of 4J School District in Lane County, Oregon, scored the pre-tests and post-tests for the phase 1 clinical trial. Elizabeth Landry, Diana Ray and other students of Shenandoah University assisted in the phase 1 clinical trial intervention. We also thank the school-based therapists in Arlington and Fairfax counties, VA and in Eugene, OR; the CompuWrite Camp and participants at George Mason University; the senior students in the OSU School of Mechanical, Industrial, & Manufacturing Engineering Class of 2009, the OSU machine shop; and the Boys and Girls Club of the Northern Shenandoah Valley.