Design of carbon dioxide sensor for capnography

As discussed in previous chapters, carbon dioxide (CO 2 ) gas released by human body is a notable excretory product from cellular respiration of living organism in identifying several respiratory and pulmonary illness. Among many, asthma as the primary respiratory disease is one of the key diseases that can be diagnosed with the evaluation of parameters identified from CO 2 released by a patient. Regarding that, Chapters 3–5 have detailed about capnography, a noninvasive device that uses sensing technology and measures human respiration CO 2 from the expired gasses and an incessant plot of exhaled CO 2 over time, known as a capnogram. Capnography detects CO 2 from expired gas and extracts the featured CO 2 parameters such as end-tidal CO 2 (EtCO 2 ), respiratory rate slope angles, and many more, which can be used to differentiate asthmatic and nonasthmatic conditions. For an effective capnography, a high-performance CO 2 sensor is necessary. There are a variety of CO 2 sensors developed and a huge effort is involved in improving the technology for highly sensitive CO 2 sensors. The present chapter discusses the types of CO 2 sensors and its contribution for diagnosing asthma, as well as in enhancing capnography.