Wearable breath monitoring via a hot-film/calorimetric airflow sensing system.

Monitoring the breath information from two nostrils can detect breath-related health problems. In this work, we introduce a wearable hot-film/calorimetric breath sensing system composed of a hot-film senor in the center and two calorimetric sensors on two sides. This design has the advantages of low power consumption of 60 mW and good sensitivity to simultaneously measure the mix breath velocity and individual breath airflow signals from the two nostrils. In prototype demonstrations, abnormal breath conditions (apnea, hypopnea, polypnea) and the asymmetric breath conditions between the right and left nostril have been recorded and analyzed for potential usages in the diagnosis of specific breath-related diseases.