Nonlinearity in pulmonary airway dynamics
TL;DR: Control theory is used for nonlinearization of the dynamic process by considering the presence of an additional pressure source actuating the basic model and accounting for the system nonlinearity, which is found to be predominantly present during the expiratory phase.
Abstract: The paper describes an approach for determining nonlinearity in the pulmonary airway dynamic system, assuming a crude but linear model of the system. The linear electrical analogue representation of the dynamic system, found to be applicable only during the inspiratory phase of the respiration process, is considered as the basic model of the system. Control theory is used for nonlinearization of the dynamic process by considering the presence of an additional pressure source actuating the basic model and accounting for the system nonlinearity, which is found to be predominantly present during the expiratory phase. On analysis of the basic model, the form of the nonlinearizing signal is determined by examining the closeness between the model response and actual response of a typical patient. The use of this signal in a modified modelling of the process and in its computer simulation study is indicated.
Citations
More filters
TL;DR: A method for the straightforward estimation of the parameters in lumped continuous linear models of respiratory mechanics is presented, where a discrete-time model is obtained from the samples of input-output data and then transformed into a conuous- time model.
Abstract: A method for the straightforward estimation of the param eters in lumped continuous linear models of respiratory mechanics is presented in this paper. First, a discrete-time model is obtained from the samples of input-output data and then transformed into a conuous-time model.
33 citations
References
More filters
358 citations
64 citations
TL;DR: A mathematical model has been derived that describes the pressure-flow relationship in the ventilatory system under conditions of constant lung volume and a collapsible airway segment is included to model compression of the airways during expiration.
Abstract: A mathematical model has been derived that describes the pressure-flow relationship in the ventilatory system under conditions of constant lung volume. The parameters of the model include small airway resistance, large airway resistance, and lung elastic recoil. A collapsible airway segment is included to model compression of the airways during expiration.
47 citations
TL;DR: In this article, necessary conditions for optimal parameter selection of stochastic Ito differential systems are developed and the main result, a necessary condition for optimality, is presented in theorem 1.
Abstract: In this paper necessary conditions for optimal parameter selection of stochastic Ito differential systems are developed Our main result, a necessary condition for optimality, is presented in theorem 1 Its proof is based on some recent results of Fleming (1968, p 210), The result is illustrated by its application to the problem of determination of the optimal feedback gain matrix for a noisy linear regulator
3 citations
TL;DR: In this article, an approach for an exact model of a physiological system from its basic electrical representation is described, where the existing basic linear model of human arterial circulatory system applicable during diastole period is first analysed and identified by adopting a mathematical technique.
Abstract: This paper describes an approach for an exact model of a physiological system from its basic electrical representation. The existing basic linear model of human arterial circulatory system applicable during diastole period is first analysed and identified by adopting a mathematical technique. The model is then non-linearized by considering the presence of an additional actuating signal applicable during systole period. The form of the actuating signal is then determined by examining the resemblance between the actual and model responses. The use of this signal on achieving a modified model of the system is indicated.
3 citations