Book III: Scientific and Research Applications in Medical Care: Estimating Respiratory Mechanical Parameters during Mechanical Ventilation

We propose an algorithm for the estimation of the parameters of the mechanical respiratory system. The algorithm is based on non linear regression analysis with a two-compartment respiratory system model. The model used allows us to take account of the non homogeneous properties of the lungs which may cause uneven distribution of ventilation and thus affect the gas exchange in the lungs. The estimation of the parameters of such a model permits the optimization of the type of ventilation to be used in patients undergoing respiratory treatment. This can be done bearing in mind the effects of the mechanical ventilation on venous return as well as the quality of gas exchange. We have valued the performances of the estimation algorithm which is proposed on the basis of the agreement between the data and the model response, of the stability of the parameter estimates and of the standard deviations of the parameters. The parameter estimation algorithm described does not have recourse to the examination of the impedance spectra and is completely independent of the type of ventilator employed.