HapticLink: A Force-based Haptic Feedback System for Single and Double Lower-Limb Amputees.

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Human-Computer Interaction

Background:

• Lower limb amputation impacts millions, leading to balance issues due to lost sensory feedback and proprioception.
• This deficit increases the risk of falls and injuries for individuals with lower limb prosthetics (LLP).

Purpose of the Study:

• To develop and evaluate HapticLink, a haptic feedback system designed to improve balance and prosthesis embodiment in LLP users.
• To assess the efficacy of using prosthetic foot weight distribution for sensory substitution.

Main Methods:

• Developed HapticLink system integrating four FlexiForce A201 sensors, a microcontroller, and four Vibration Motors (VM).
• Tested sensor repeatability and linearity, selecting A201 sensors as optimal.
• Conducted quantitative (perception tests) and qualitative assessments with single and double lower-limb amputees.

Main Results:

• FlexiForce A201 sensors demonstrated optimal performance for the intended application.
• HapticLink successfully conveyed prosthetic foot weight distribution as haptic feedback.
• Quantitative perception tests showed high accuracy (avg. 94.44% Directional, 79.17% Frequency, 100% Manually Applied Directional Perception).
• Qualitative feedback indicated potential for improved ambulation and prosthesis acceptance.

Conclusions:

• HapticLink effectively provides sensory feedback for lower limb amputees.
• The system shows promise in aiding ambulation for both single and double lower-limb amputees.
• A simple force sensor and haptic motor system can be clinically relevant for improving prosthetic use.