Tactile Sensing Enables Shared Control of Prosthetic Hand with Multi-Stage Grasping and Force Level Switching Functions

Shared control with multiple functions of myoelectric prosthetic hand enables individuals with amputation to achieve more precise control with less fatigue, which improves the acceptance of myoelectric prosthetic hands. In this paper, we propose introducing two new functions for prosthetic hands enabled by a shared control based on fingertip tactile sensing: Multi-Stage Grasping and Force Level Switching. A user study involving eight able-bodied and three amputee participants was conducted to assess the performance of our proposed functions in selected common daily life tasks. The purpose of the assessment is to determine if the proposed functions based on tactile sensing can improve the objective performance of the prosthetic hand as well as the subjective experience of users. The results demonstrated the potential benefit of our proposed functions, allowing for faster completion of multiple objects grasp-and-place tasks compared to existing myoelectric control, as well as a higher success rate of force adjustment tasks. Moreover, the tactile-based shared control with our proposed functions reduced muscle use and obtained positive user feedback.