ABSTRACT
It is difficult to select the appropriate ventilation mode in clinical mechanical ventilation. This paper presents a nonlinear multi-compartment lung model to solve the difficulty. The purpose is to optimize respiratory airflow patterns and get the minimum of the work of inspiratory phrase and lung volume acceleration, minimum of the elastic potential energy and rapidity of airflow rate changes of expiratory phrase. Sigmoidal function is used to smooth the respiratory function of nonlinear equations. The equations are established to solve nonlinear boundary conditions BVP, and finally the problem was solved with gradient descent method. Experimental results showed that lung volume and the rate of airflow after optimization had good sensitivity and convergence speed. The results provide a theoretical basis for the development of multivariable controller monitoring critically ill mechanically ventilated patients.
Subject(s)
Humans , Exhalation , Lung , Physiology , Models, Biological , Nonlinear Dynamics , Pulmonary Ventilation , Respiration , Respiration, Artificial , Tidal VolumeABSTRACT
AIM: To study fingerprint and characteristic components of the essential oil of processed Rhizoma Kaempferiae in order to control quality. METHODS: The fingerprint and characteristic components of the essential oil of 10 samples were determined by GC-MS. RESULTS: trans-Ethyl-p-methoxycinnamate,cis-Ethyl-p-methoxycinnamate,trans-Ethylcinnamate,n-Pentadecane,3-Carene,Borneol, 8-Heptadecene,Cyperene,Heptadecane,Globulol,Eucalyptol,cis-Methyl-p-methoxycinnamate and Eucarvone were gained in 10 samples,and relative contents of 13 components added up to 94.5%-98.2% of the total essential oil.The retention time and peak area of 13 components had built the characteristic fingerprint of essential oil of processed Rhizoma Kaempferiae. CONCLUSION: The commercial samples collected from various sources shows a strong similarity.The method has a good repeatability and can be used to control quality of processed Rhizoma Kaempferiae.