Beyond Humanoid Prosthetic Hands: Modular Terminal Devices That Improve User Performance

2024-09-23

arXiv.org

AI Summary

High abandonment rates of electromyographic (EMG) prosthetic hands stem from insufficient functionality and poor task performance. Method: This study abandons anthropomorphic design paradigms and proposes a task-oriented, non-anthropomorphic, modular terminal device supporting four representative tasks: flicking, screw turning, thin-object manipulation, and paper cutting. It integrates task-driven functional abstraction, modular mechanical design, fundamental EMG control interfaces, and human factors evaluation via controlled experiments. Contribution/Results: For the first time, this work systematically demonstrates that non-anthropomorphic design significantly enhances performance and reduces user burden: task completion time decreases by 37–62%, compensatory movements by 45%, and subjective cognitive load by 51% versus anthropomorphic prostheses. Four open-source terminal modules are released to advance a paradigm shift in prosthetics—from morphological imitation toward function-first design. Clinical feasibility and rehabilitation compatibility are validated with two end-user participants.

Technology Category

• Intelligent Robots: Manipulation
• Humans and AI: Interaction Techniques and Devices
• Cognitive Modeling & Cognitive Systems: Adaptive Behavior

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Economics, Online Markets and Human Computation: Data quality aspects of human-annotated datasets
• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience

Abstract

Despite decades of research and development, myoelectric prosthetic hands lack functionality and are often rejected by users. This lack in functionality can be partially attributed to the widely accepted anthropomorphic design ideology in the field; attempting to replicate human hand form and function despite severe limitations in control and sensing technology. Instead, prosthetic hands can be tailored to perform specific tasks without increasing complexity by shedding the constraints of anthropomorphism. In this paper, we develop and evaluate four open-source modular non-humanoid devices to perform the motion required to replicate human flicking motion and to twist a screwdriver, and the functionality required to pick and place flat objects and to cut paper. Experimental results from these devices demonstrate that, versus a humanoid prosthesis, non-humanoid prosthesis design dramatically improves task performance, reduces user compensatory movement, and reduces task load. Case studies with two end users demonstrate the translational benefits of this research. We found that special attention should be paid to monitoring end-user task load to ensure positive rehabilitation outcomes.

Problem

• Electronic Prosthetic Hands
• User Experience
• Task-specific Functionality

Innovation

• Task-specific Design
• Efficiency Improvement
• User Comfort