Real time monitoring of human respiration rate using infrared thermography

Infrared thermography (IRT) has gained significant popularity in biomedical instrumentation. One of its important applications is the contactless monitoring of the human respiration rate (RR). This paper reports application of IRT for human RR monitoring using a passive thermography approach. The variation in nostril temperature during breathing is observed using a thermal camera, and the breathing signals (BS) are obtained. The BS have a low signal to noise ratio (SNR), which is improved by using the Butterworth filter. The signals are monitored under different breathing and ambient conditions, and the heat exchange mechanisms occurring under these scenarios are discussed in detail. Further, the emissivity value of the human volunteers of different complexion and skin types is analyzed. The mean emissivity value obtained in the study is 0.98.