Feasibility of error-based electrotactile and auditive feedback in prosthetic walking

Area of Science:

• Prosthetics and Biomechanics
• Rehabilitation Engineering
• Human-Computer Interaction

Background:

• Feedback in upper-leg prostheses is possible but often slow or difficult to interpret.
• Transfemoral amputees experience insecurity and fear of falling due to prosthesis instability.
• Error-based feedback aims to provide alerts during undesired events to enhance prosthetic control.

Purpose of the Study:

• To evaluate the effectiveness of electrotactile and auditory error-based feedback during gait perturbations in transfemoral prosthesis users.
• To determine if feedback provided only during undesired events can improve reaction time and stability.
• To assess the potential of these feedback modalities for improving prosthetic limb control and reducing fall risk.

Main Methods:

• Nine healthy subjects participated in a study using a prosthetic simulator.
• Subjects experienced simulated gait perturbations at the end of the swing phase.
• Three feedback conditions were tested: no feedback, electrotactile feedback, and auditory feedback.

Main Results:

• Auditory feedback resulted in a modest improvement in reaction time of 40 ms compared to no feedback.
• Electrotactile feedback did not yield any significant changes in reaction time.
• Perturbation detection rates were not analyzed, limiting the interpretation of feedback effectiveness.

Conclusions:

• The tested error-based feedback methods, particularly auditory feedback, offer insufficient improvement for practical application in upper-leg prostheses.
• Further research is needed to optimize feedback strategies for transfemoral amputees to enhance stability and reduce fall incidence.
• Developing more effective feedback systems is crucial for improving user confidence and functional outcomes in prosthetic limb use.