Modeling of the humidification process in a typical Continuous Positive Airway Pressure (CPAP) device is described in this chapter, by developing a model that predicts the mask absolute humidity level and air temperature due to the physical, mechanical, and thermodynamic behavior of individual elements. Such a model is formulated by incorporating the relationship between the inputs and measurable outputs in terms of air conditions at the mask. The system model inputs include machine settings and sensor readings.

Modeling a system in this fashion is shown to accurately predict the behavior of a typical system humidifier, heated air delivery tube, flexible...