Modeling and parameter identification of the human respiratory system

The human respiratory response to breathing an excess of carbon dioxide gas is modeled on physiological grounds as a linear time-varying second order system. The parameters corresponding to the gains, time constants, set point, and noise powers are identified by both least squares and maximum likelihood methods. The purpose is both to find the site of action of drugs and to gain understanding of this part of the respiratory control system. It is concluded the maximum likelihood method is necessary for drug studies, but for physiological modeling the least squares is usually sufficient.