A biosignal analysis for reducing prosthetic control durations: a proposed method using electromyographic and...

Area of Science:

• Biomechanics
• Neuroprosthetics
• Biomedical Engineering

Background:

• Developing intuitive and responsive prosthetic control systems is crucial for improving user mobility and function.
• Existing prosthetic control algorithms can benefit from enhanced methods for detecting movement intensity.
• Electromyography (EMG) and mechanomyography (MMG) offer potential for real-time movement analysis.

Purpose of the Study:

• To propose and validate a novel methodology using EMG and MMG to determine movement intensity.
• To investigate the relationship between muscle contraction intensity and MMG signal characteristics (duration, amplitude) and electromechanical delay.
• To assess the potential application of these measurements in improving prosthetic control algorithms.

Main Methods:

• Ten male participants performed isometric leg extension contractions at 20%, 40%, 60%, 80%, and 100% of their maximal voluntary isometric contraction (MVIC).
• Mechanomyography (MMG) signal duration and amplitude, along with electromechanical delay (EMD), were measured during each contraction.
• Measurements were analyzed in relation to varying contraction intensities.

Main Results:

• MMG signal duration decreased significantly with increasing contraction intensity (20% < 40%=60% < 80% < 100% MVIC).
• MMG signal amplitude increased significantly with increasing contraction intensity (20% < 40%=60% < 80% < 100% MVIC).
• Electromechanical delay (EMD) consistently decreased with each incremental increase in contraction intensity, observed within 40 ms of EMG onset.

Conclusions:

• The study demonstrates that MMG signal duration and amplitude, along with EMD, are reliable indicators of muscle contraction intensity.
• These biomechanical measurements can be integrated into prosthetic control systems to enable earlier and more accurate detection of movement intent.
• Implementing these findings may lead to reduced prosthetic grasp times and more intuitive control for users, enhancing overall prosthetic functionality.