An optoelectronic muscle contraction sensor for prosthetic hand application

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Sensor Technology

Background:

• Surface electromyography (sEMG) is a standard for prosthetic control but faces challenges like noise, artifacts, and high costs.
• These limitations necessitate the development of alternative muscle activity sensing technologies.

Purpose of the Study:

• To introduce and evaluate a new optoelectronic muscle (OM) sensor as a viable alternative to sEMG.
• To assess the OM sensor's precision, stability, and performance in measuring muscle contractions for assistive device control.

Main Methods:

• Developed an optoelectronic sensor integrating near-infrared light emitters and phototransistors to detect muscle surface displacement.
• Implemented signal processing to generate an output proportional to muscle contraction.
• Compared the OM sensor's performance against sEMG in forearm muscle activity detection.
• Utilized the OM sensor for controlling a servomotor.

Main Results:

• The OM sensor produced a 0-5V output proportional to muscle contraction.
• Demonstrated comparable static and dynamic features to sEMG sensors.
• Exhibited superior signal-to-noise ratio and signal stability compared to sEMG.
• Successfully controlled servomotor rotation using the OM sensor data.

Conclusions:

• The developed OM sensor is a promising, high-performance alternative to sEMG for measuring muscle activity.
• This technology can effectively provide muscle contraction information for controlling assistive devices.
• The OM sensor offers improved signal quality and stability, potentially reducing costs in rehabilitation technology.