Nonlinear model for mechanical ventilation of human lungs

A complex nonlinear model for mechanical ventilation, its computer implementation and validation are presented. The model includes the morphometry-based symmetrical structure of the 23 airway generations, dynamic properties of the respiratory system, as well as the description of a ventilator. Distributed character of airway mechanical properties is taken into account when determining airway inertance, resistance and compliance, including turbulence of flow, airway collapsing and the wave speed theory. In effect, the airway parameters vary within the ventilatory cycle and their values are nonlinear functions of control signals. Results of simulations corresponding to normal conditions and airway narrowing are consistent with the published experimental data. The model enables investigations on how specific pathological changes influence the signals and physiological variables during mechanical ventilation, as well as testing known and developing new algorithms tracking time-variability of the respiratory parameters.

[1]  J. E. W. Beneken,et al.  Serial lung model for simulation and parameter estimation in body plethysmography , 1991, Medical and Biological Engineering and Computing.

[2]  H. Hoogsteden,et al.  Detection of flow limitation in mechanically ventilated patients , 2001, Intensive Care Medicine.

[3]  J. Bates,et al.  Effect of stochastic heterogeneity on lung impedance during acute bronchoconstriction: a model analysis. , 1997, Journal of applied physiology.

[4]  A. G. Polak,et al.  Computational Model for Forced Expiration from Asymmetric Normal Lungs , 2003, Annals of Biomedical Engineering.

[5]  J P Perdrix,et al.  A computer program for automatic measurement of respiratory mechanics in artificially ventilated patients. , 1995, Computer methods and programs in biomedicine.

[6]  A. Cappello,et al.  Influence of flow pattern on the parameter estimates of a simple breathing mechanics model , 1995, IEEE Transactions on Biomedical Engineering.

[7]  M. Tavola,et al.  Pulmonary and chest wall mechanics in anesthetized paralyzed humans. , 1991, Journal of applied physiology.

[8]  B Suki,et al.  How inhomogeneities and airway walls affect frequency dependence and separation of airway and tissue properties. , 1996, Journal of applied physiology.

[9]  P. Sterk,et al.  Pressure-volume analysis of the lung with an exponential and linear-exponential model in asthma and COPD. Dutch CNSLD Study Group. , 1995, The European respiratory journal.

[10]  J. Bates,et al.  Estimating respiratory mechanics in the presence of flow limitation. , 1999, Journal of applied physiology.

[11]  Fritz Rohrer,et al.  Der Strömungswiderstand in den menschlichen Atemwegen und der Einfluss der unregelmässigen Verzweigung des Bronchialsystems auf den Atmungsverlauf in verschiedenen Lungenbezirken , 1915, Pflüger's Archiv für die gesamte Physiologie des Menschen und der Tiere.

[12]  D. L. Fry,et al.  The mechanics of pulmonary ventilation in normal subjects and in patients with emphysema. , 1954, The American journal of medicine.

[13]  N. Koulouris,et al.  Detection of expiratory flow limitation during mechanical ventilation. , 1994, American journal of respiratory and critical care medicine.

[14]  J. Clark,et al.  Airway mechanics, gas exchange, and blood flow in a nonlinear model of the normal human lung. , 1998, Journal of applied physiology.

[15]  J. Clark,et al.  Mathematical modeling of pulmonary airway dynamics. , 1973, IEEE transactions on bio-medical engineering.

[16]  C. Cobelli,et al.  On-line monitoring of intrinsic PEEP in ventilator-dependent patients. , 2000, Journal of applied physiology.

[17]  J. Bates,et al.  Estimation of time-varying respiratory mechanical parameters by recursive least squares. , 1991, Journal of applied physiology.

[18]  John W. Clark,et al.  Analog Computer Simulation of Maximum Expiratory Flow Limitation , 1975, IEEE Transactions on Biomedical Engineering.

[19]  Guido Avanzolini,et al.  Nonlinear Mechanisms Determining Expiratory Flow Limitation in Mechanical Ventilation: A Model-Based Interpretation , 2003, Annals of Biomedical Engineering.

[20]  Michel Badet,et al.  Time course of expiratory flow limitation in COPD patients during acute respiratory failure requiring mechanical ventilation. , 2003, Chest.

[21]  D Elad,et al.  Dynamic model of the bronchial tree. , 1993, Journal of biomedical engineering.

[22]  Claudio Cobelli,et al.  A Morphometric Model of Lung Mechanics for Time-Domain Analysis of Alveolar Pressures during Mechanical Ventilation , 2002, Annals of Biomedical Engineering.

[23]  André Eberhard,et al.  A program based on a 'selective' least-squares method for respiratory mechanics monitoring in ventilated patients , 2003, Comput. Methods Programs Biomed..

[24]  E. Weibel.  Morphometry of the Human Lung , 1965, Springer Berlin Heidelberg.

[25]  T A Wilson,et al.  A computational model for expiratory flow. , 1982, Journal of applied physiology: respiratory, environmental and exercise physiology.

[26]  A Lymberis,et al.  Expiratory flow limitation and intrinsic positive end-expiratory pressure at zero positive end-expiratory pressure in patients with adult respiratory distress syndrome. , 2000, American journal of respiratory and critical care medicine.

[27]  P. Barbini,et al.  Estimating respiratory mechanical parameters of ventilated patients: a critical study in the routine intensive-care unit , 1994, Medical and Biological Engineering and Computing.

[28]  R Peslin,et al.  Density dependence of respiratory input and transfer impedances in humans. , 1988, Journal of applied physiology.

[29]  H J Colebatch,et al.  Use of an exponential function for elastic recoil. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[30]  E. D'Angelo,et al.  Effect of inspiratory flow waveform on work on endotracheal tubes: a model analysis , 1999, Intensive Care Medicine.

[31]  D B Reynolds.  Steady expiratory flow-pressure relationship in a model of the human bronchial tree. , 1982, Journal of biomechanical engineering.

[32]  J. Bates,et al.  Measurement of alveolar pressure in closed-chest dogs during flow interruption. , 1989, Journal of applied physiology.

[33]  A. G. Polak,et al.  A forward model for maximum expiration , 1998, Comput. Biol. Medicine.

[34]  J Milic-Emili,et al.  Chest wall interrupter resistance in anesthetized paralyzed humans. , 1994, Journal of applied physiology.

[35]  J Guttmann,et al.  Dynamic respiratory system mechanics in infants during pressure and volume controlled ventilation. , 2001, The European respiratory journal.

[36]  G Avanzolini,et al.  Effect of compliant intermediate airways on total respiratory resistance and elastance in mechanical ventilation. , 2001, Medical engineering & physics.

[37]  P. Behrakis,et al.  Volume and flow dependence of respiratory mechanics in mechanically ventilated COPD patients , 2003, Respiratory Physiology & Neurobiology.

[38]  D. L. Fry,et al.  Relationship between maximum expiratory flow and degree of lung inflation. , 1958, Journal of applied physiology.