Controlling a multi-degree of freedom upper limb prosthesis using foot controls: user experience

Abstract

Purpose: The DEKA Arm, a pre-commercial upper limb prosthesis, funded by the DARPA Revolutionizing Prosthetics Program, offers increased degrees of freedom while requiring a large number of user control inputs to operate. To address this challenge, DEKA developed prototype foot controls. Although the concept of utilizing foot controls to operate an upper limb prosthesis has been discussed for decades, only small-sized studies have been performed and no commercial product exists. The purpose of this paper is to report amputee user perspectives on using three different iterations of foot controls to operate the DEKA Arm. Method: Qualitative data was collected from 36 subjects as part of the Department of Veterans Affairs (VA) Study to Optimize the DEKA Arm through surveys, interviews, audio memos, and videotaped sessions. Three major, interrelated themes were identified using the constant comparative method: attitudes towards foot controls, psychomotor learning and physical experience of using foot controls. Results: Feedback about foot controls was generally positive for all iterations. The final version of foot controls was viewed most favorably. Conclusions: Our findings indicate that foot controls are a viable control option that can enable control of a multifunction upper limb prosthesis (the DEKA Arm).

Implications for Rehabilitation

• Multifunction upper limb prostheses require many user control inputs to operate. Foot controls offer additional control input options for such advanced devices, yet have had minimal study.

• This study found that foot controls were a viable option for controlling multifunction upper limb prostheses. Most of the 36 subjects in this study were willing to adopt foot controls to control the multiple degrees of freedom of the DEKA Arm.

• With training and practice, all users were able to develop the psychomotor skills needed to successfully operate food controls. Some had initial difficulty, but acclimated over time.

• Amputation
• assistive technology
• control schemes
• prosthetics

Acknowledgements

The authors acknowledge the valuable work of study coordinator Kate Barnabe, and members of the research teams at all study sites.

VANYHHS: Nicole Sasson, MD, Kenneth Breuer, CP, Roxanne Disla, OTR/L, MaryAnne Garbarini, MA, PT Dan Burgos, BOCP, Edward Sliwinski,

Tampa: Gail Latlief, DO, Melanie Harris, CPO, Samuel Phillips, PhD, CP, FAAOP, Laurel Adams-Koss, MOT, OTR/L, Deborah Gavin-Dreschnack, PhD, Jemy Delikat, MOT, OTR, Jill Ardilla, MA, Andrea Spehar, DVM, MPH, JD, N. Joseph Shamp, CPO, Steve Doerr, CPO

CFI: Lisa Smurr Walters, MS, OTR/L, CH, Ryan Blanck, LCPO, Kathryn Korp, OTD, OTR/L, Sandra Jarzombek, MA, John Fergason, CPO, Christopher Ebner, MS, OTR/L, COL Jennifer Menetrez, MD, Donald A. Gajewski, MD

Long Beach: Dana Craig, Susan Kaplan, MD, Karen Duddy, MHA, OTR/L, Jack Mark, CPO, Dorene Doi, OTR/L, Mary Jo Van Duyn, Duane Sallade, CPO

PVAMC: Susan Rizzo, MPH, Marcia Selinger, Crystal Davis, MPH, Debra Kelty, MPA, Matthew Borgia, AM, Marissa Meucci, MS