Porous-Structure Flexible Muscle Sensor for Monitoring Muscle Function and Mass

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Gerontology

Background:

• Muscle function and composition are key indicators of age-related health.
• Current assessment methods are often complex, expensive, and inaccessible for daily monitoring.
• Early detection of muscle-related issues is crucial for timely intervention.

Purpose of the Study:

• To develop a cost-effective, portable, and user-friendly sensor for daily muscle function and mass assessment.
• To evaluate the sensor's performance in distinguishing between elderly and young individuals.
• To assess the sensor's capability in predicting relative skeletal muscle mass index.

Main Methods:

• A novel porous-structured (CNT/PDMS nanocomposite) flexible piezoresistive sensor was designed and fabricated.
• The sensor was tested for its detection range, sensitivity, stability, and performance under varying conditions (temperature, perspiration).
• Gait data was collected from 23 participants (elderly and young) wearing the sensor on the gastrocnemius muscle, with machine learning models applied for analysis.

Main Results:

• The sensor demonstrated a linear detection range of 0-39 kPa with dual-stage sensitivities and maintained stable performance for over a week.
• Supervised learning achieved 93.48% accuracy in distinguishing between age groups.
• An Adaboost regression model predicted relative skeletal muscle mass index with a mean error of 2.8%.

Conclusions:

• The developed flexible sensor is a promising tool for the daily, noninvasive monitoring of muscle function and mass.
• It enables early detection and prevention of sarcopenia and other age-related muscle disorders.
• The sensor's low cost, user-friendliness, and portability make it suitable for clinical, sports, and home environments.