Low-cost portable respiration monitor based on micro hot-film flow sensor

We present a portable, low cost, sensitive respiration monitoring system based on a micro hot-film flow sensor. The sensitive component of the flow sensor is a patterned thin-film with nanometer thickness fabricated on a flexible polyimide substrate by incorporating printed circuit technique with micromachining technique. The respiratory flow measurement is under a constanttemperature mode, and the measured signals are sampled and processed using SCM and transferred to PC through USB data communication. Virtual instruments technology is applied to achieve the real-time display of respiratory flow waveform and related respiratory parameters on PC. Finally, the system is experimentally calibrated, static and dynamic characteristics of the system are acquired and the effectiveness of the system is verified.