Abstract
A method is developed to evaluate system stability for the CO 2 control of breathing in individuals by using data from the dynamics of CO 2 rebreathing and elimination. The theoretical basis of the method is a physiological model of the CO 2 respiratory control system and an explicit stability index (SI). The SI is algebraically related to the model parameters: system volume ( V s), cardiac output ( Q), circulatory transit time ( t s ), and controller gain ( G). A sequential optimization scheme is shown to yield estimates of the model parameters by comparing the alveolar ventilation and PCO 2 of the model output with corresponding experimental data. Model simulation of CO 2 rebreathing and elimination with different parameter values demonstrate that all parameters except t s have significant effect on the outputs. Least-squares estimation of the parameters using model-generated data with added noise showed good precision for all parameters (except t s ). This analysis is performed with parameter values chosen to produce overdamped and underdamped responses that would occur in normal and abnormal respiratory control systems, respectively. It is anticipated that SI values of the (overdamped) normal and (underdamped) abnormal systems differ by much more than the variation produced by imprecision of the parameter estimates. For this circumstance, the method is expected to be sensitive enough to distinguish normal from abnormal CO 2 respiratory control of individual subjects.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call