Influence of force feedback on grasp force modulation in prosthetic applications: a preliminary study

Area of Science:

• Biomedical Engineering
• Neuroscience
• Rehabilitation Robotics

Background:

• Human movement relies on combined feed-forward and feedback motor control.
• Impaired sensory input (neuropathies, amputation) affects tasks like grip force modulation.
• Prosthetic hands often lack nuanced sensory feedback, limiting functionality.

Purpose of the Study:

• To evaluate a novel force feedback device (CUFF) integrated with the SoftHand Pro (SHP) prosthetic hand.
• To compare grip force modulation using a native hand, SHP without feedback, and SHP with CUFF feedback.
• To assess the impact of haptic feedback on object manipulation in prosthetic users.

Main Methods:

• A preliminary study involving subjects lifting objects of varying weights.
• Comparison of three conditions: native hand, SHP without feedback, SHP with CUFF feedback.
• Analysis of grip force modulation and overall grip force across conditions.

Main Results:

• Significant differences observed between the native hand and both SHP conditions.
• No significant difference found between the SHP without feedback and SHP with CUFF feedback conditions.
• Preliminary data suggests CUFF feedback might reduce overall grip force, but not improve modulation to object weight.

Conclusions:

• The CUFF device shows potential for reducing grip force in prosthetic users.
• High subject variability may have masked significant improvements in grip force modulation.
• Further research with enhanced training or customized feedback is warranted to optimize prosthetic hand control.