Vibrotactile grasping force and hand aperture feedback for myoelectric forearm prosthesis users

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Human-Computer Interaction

Background:

• Myoelectric forearm prostheses lack crucial user feedback on grasping force and hand aperture.
• Vibrotactile feedback has shown promise in enhancing grasping tasks for healthy individuals, but lacks validation in potential users.

Purpose of the Study:

• To investigate the effectiveness of vibrotactile feedback for hand aperture and grasping force in individuals with upper-limb loss performing virtual grasping tasks.
• To evaluate the impact of sensory feedback on object handling performance in prosthesis users.

Main Methods:

• A cross-over trial involving 10 subjects with upper-limb loss.
• Subjects performed virtual grasping tasks using a virtual hand, receiving vibrotactile feedback for hand aperture and grasping force.
• Feedback was delivered via coin motors for aperture and a miniature stimulator or coin motors for force.

Main Results:

• Correctly applied hand apertures and grasping force levels were significantly higher with vibrotactile feedback compared to no feedback.
• Visual feedback yielded superior results to vibrotactile feedback, but task durations were comparable across all conditions.
• Grasping performance was evaluated for potential users of myoelectric prostheses.

Conclusions:

• Vibrotactile feedback for grasping force and hand aperture enhances grasping performance in individuals with upper-limb loss.
• This study represents a foundational step towards implementing sensory feedback in myoelectric forearm prostheses.
• Further research is needed to determine the added value of this feedback in daily-life activities.