Vibrotactile interface for combined normal and shear force feedback for hand prostheses

Le résumé fourni par la source

Upper limb amputations severely impair motor and sensory functions, affecting independence in daily life. Myoelectric prostheses can restore motor function by translating muscle signals into movement, but they often lack adequate sensory feedback, which is essential for intuitive control. The literature presents many approaches to provide grasping force feedback, but they focus only on the normal force component. However, human mechanoreceptors are also sensitive to shear forces, which are crucial for effective and safe object manipulation. This study proposes a novel encoding scheme using multiple vibration motors to convey both normal and shear components of grasping force, measured by custom tactile sensors placed on prosthetic fingers. The system was preliminarily tested in 17 non-disabled participants while doing two different experiments. The first evaluated whether users could identify object weight and force direction from the feedback. The second assessed whether the added shear feedback improved slippage detection compared to normal force feedback alone. Participants achieved high success rates in decoding weight and direction (median: 80–88%), demonstrating that the feedback was intuitive even without prior systematic training. Moreover, slippage detection improved significantly with the inclusion of shear force feedback: participants recognized slippage in 82% of trials with combined feedback, compared to 64% with only normal force. Overall, this preliminary study highlights the potential of integrating multidirectional force feedback in hand prosthetics to improve safety and usability, especially by detecting and reacting to abrupt force changes during object manipulation.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.