A Differential Inertial Wearable Device for Breathing Parameter Detection: Hardware and Firmware Development,...

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Respiratory Monitoring

Background:

• Current respiration monitoring technologies are often expensive, bulky, and inaccurate, especially with patient movement.
• Limitations necessitate novel, non-invasive, and accurate solutions for diverse applications like healthcare and athletic performance.
• Inertial sensors offer a discreet method to measure breathing-induced chest movements.

Purpose of the Study:

• To develop and test an inertia-based chest band for accurate and non-invasive breathing monitoring.
• To utilize a differential approach with two inertial measurement units (IMUs) for enhanced signal detection.
• To extract key respiratory parameters, including respiration rate (RR), inhalation/exhalation time (TI/TE), and flow rate (V).

Main Methods:

• Developed a chest band incorporating two IMUs (chest and back) to capture differential inertial signals.
• Integrated a low-power microcontroller for data acquisition and processing to extract breathing parameters.
• Employed a back IMU as a reference for accurate measurements.
• Utilized a BLE transceiver for wireless data transmission to a mobile application.

Main Results:

• Demonstrated high correlation (r¯ = 0.92) and low mean difference (MD¯ = -0.27 BrPM) for respiration rate (RR) compared to a reference.
• Achieved low limits of agreement (LoA¯ = +1.16/-1.75 BrPM) and mean absolute error (MAE¯ = 1.15%) for RR.
• Accurately measured other breathing parameters (TI, TE, IER, V) with an MAE ≤5%.

Conclusions:

• The developed dual-inertia chest band is a viable solution for effective long-term breathing monitoring.
• The device provides accurate respiratory parameter measurements in both stationary and moving users.
• This technology overcomes limitations of traditional methods, offering a non-obtrusive and precise alternative.