A Wireless Integrated System for COPD Monitoring Using a High-Sensitivity, Wide-Dynamic Range MEMS Flow Sensor

This study presents a wireless, integrated, and portable monitoring system for chronic obstructive pulmonary disease (COPD), featuring a highly sensitive and wide-dynamic range MEMS-based flow sensor, alongside a high-accuracy respiratory monitoring algorithm. The flow sensor was fabricated using a CMOS-compatible MEMS process, achieving low-power consumption (3.76 mW), high sensitivity (356.32 mV/(m/s)/W), and a wide dynamic range from –16.7 to 16.7 m/s. To meet the requirements of human respiratory monitoring and spirometric evaluation, a bypass channel was incorporated, enabling bi-directional flow measurement with an extended range of ±1000 L/min. An abnormal respiration detection algorithm was developed based on critical respiratory parameters, including respiratory cycle, respiratory rate (RR), minute ventilation volume (MVV), and tidal volume (TV). Additionally, an enhanced interpolation method was integrated to improve the accuracy of spirometry testing, facilitating early-stage COPD screening. Experimental validation (1.13% volume error, average percentage error of –2.74% of all spirometry indicators) demonstrated that the proposed portable system delivers performance comparable to conventional, bulky medical spirometers, highlighting its strong potential for convenient, real-time respiratory monitoring and spirometric assessment in COPD management.