Testing of a 3D printed hand exoskeleton for an individual with stroke: a case study

Abstract

Introduction

Many individuals with stroke still have functional difficulties with their affected hand after going through a rehabilitation program. A 3D printed upper limb exoskeleton was designed for an individual who had a stroke. Functional and neuromuscular outcomes were measured using his affected hand with and without a 3D printed passive exoskeleton. The goal of this study was to determine the functional and neuromuscular changes induced by the 3D printed exoskeleton in a participant with stroke.

Materials and methods

The functional ability of the exoskeleton was assessed using the Fugl-Meyer Assessment and the Box and Block Test. Strength testing and muscle activation of the participant’s forearms were measured during maximal voluntary contractions. Furthermore, EMG was measured during the Box and Block Test and satisfaction and usability of the 3D printed exoskeleton were assessed using standardized questionnaires.

Results

The exoskeleton improved both the participant’s Fugl-Meyer Assessment scores and Box and Block test scores compared to not wearing the device. The subject had increased EMG activation in his extensor when wearing the exoskeleton.

Conclusion

The inexpensive 3D printed exoskeleton was effective in assisting the participant with stroke during the functional assessments and has the potential to be used to help regain function of the hand in the home setting of an individual with stroke.

IMPLICATIONS FOR REHABILITATION

• A 3D printed passive hand exoskeleton may assist to accomplish rehabilitation outcomes by increasing function of the affected hand of patients with stroke.

• The use of this hand exoskeleton may be used to improve gross hand dexterity and assist with functional grasps during rehabilitation sessions with a lower patient's level of perceived exertion.

• The use of new antimicrobial 3D printing polymers can be effectively implemented to manufacture assistive devices to prevent skin infections during rehabilitation.

Keywords:

• Hand
• exoskeleton
• additive manufacturing
• computer-aided design
• stroke
• biomechanics

Acknowledgements

The authors would like to thank the subject for participating in our study. The authors would like to thank all of the students who helped with the data collection at the Biomechanics Research Building at the University of Nebraska at Omaha. Additionally, the authors would like to thank Dr. Jim Brown for his support. Finally, thanks to Copper3D Inc. for donating the antimicrobial 3D printing filament for the construction of the hand exoskeleton.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Institutes of Health under grants (R15HD094194) and (P20GM109090), the GRACA/The Office of Research and Creative Activity at the University of Nebraska at Omaha, and the NASA Nebraska Space Grant.