Flexible Insole Sensors with Stably Connected Electrodes for Gait Phase Detection

Area of Science:

• Materials Science
• Biomedical Engineering
• Robotics

Background:

• Gait analysis is crucial for assessing human physical information and has applications in disease diagnosis, fall prevention, rehabilitation, and human-robot interaction.
• Real-time monitoring of plantar pressure is essential for accurate gait analysis.

Purpose of the Study:

• To develop a novel pressure-sensitive insole for real-time planar pressure monitoring.
• To investigate the relationship between plantar pressure distribution and lower limb joint angles.
• To validate the insole's capability for accurate gait phase division.

Main Methods:

• Designed and investigated a surface-processed conductive rubber for pressure sensing.
• Fabricated a pressure-sensitive insole by integrating sensors with inkjet-printed electrodes and a flexible substrate.
• Implemented wireless transmission of resistive signals for real-time data acquisition.
• Utilized a machine learning algorithm (k-Nearest Neighbor) combined with visual-based gait monitoring to analyze data.

Main Results:

• The developed pressure sensors exhibited stable contact resistance, simple manufacturing, and high mechanical durability.
• The pressure-sensitive insole demonstrated good sensing performance and was easily assembled.
• A clear relationship between plantar pressure distribution and lower limb joint angles was established.
• The device successfully enabled accurate division of gait into distinct phases.

Conclusions:

• The developed pressure-sensitive insole offers a promising tool for real-time gait analysis.
• The technology has significant potential applications in healthcare, rehabilitation, and human-robot interaction.
• This innovation advances the field of wearable sensing for biomechanical monitoring.