Respiratory Motion Sensor Measuring Capacitance Constructed across Skin in Daily Activities

Area of Science:

• Biomedical Engineering
• Wearable Sensors
• Physiological Monitoring

Background:

• Respiration causes changes in skin thickness, which can be measured using capacitance-based sensors.
• Previous methods lacked stable electrode contact, affecting signal quality.
• A thin dressing film can improve electrode adhesion and long-term wearability.

Purpose of the Study:

• To develop and evaluate a stable respiratory sensor for detecting respiration and body volume changes.
• To assess the efficacy of a 7-μm-thick dressing film in stabilizing electrode fit.
• To demonstrate the sensor's capability in monitoring physiological signals during daily activities.

Main Methods:

• A capacitance-based respiratory sensor with electrodes attached to the abdomen was utilized.
• A 7-μm-thick dressing film was employed to stabilize the electrode-skin interface.
• Respiration and baseline capacitance changes were recorded during rest, exercise, and 6-minute walks.

Main Results:

• The dressing film ensured stable electrode placement, enabling long-term wear.
• Cyclic capacitance changes reliably indicated respiration.
• Baseline capacitance shifts provided insights into sensor signal quality and minute body volume variations.
• The sensor successfully captured respiratory signals during various daily activities.

Conclusions:

• The developed sensor system, utilizing a stabilizing film, offers a reliable method for respiratory monitoring.
• This technology can detect both respiration and subtle body volume changes, indicating potential for continuous physiological tracking.
• The findings support the use of this sensor for unobtrusive, long-term health monitoring during everyday life.