Mathematical and Computational Applications, Vol. 19, No. 2, pp. 144-151, 2014 ESTIMATION OF MUCUS CLEARANCE IN PULMONARY AIRWAYS BY MEANS OF A REGRESSION MODEL Shahriar Shamil Uulu 1 , Halil Rıdvan Öz 1* , Ferhat Karaca 2 and Cahit A. Evrensel 3 1 Department of Genetics and Bioengineering, Fatih University, 34500 B. Çekmece, Istanbul, Turkey 2 Department of Civil Engineering, Fatih University, 34500 B. Çekmece, Istanbul, Turkey 3 Department of Mechanical Engineering, University of Nevada Reno, Reno, NV, USA hroz@fatih.edu.tr Abstract- In this study, a multivariate regression analysis was performed on a dataset obtained from experimental tracheal model for mucus clearance in pulmonary airways. Several simulations have been done to verify the validity of the generated regression model. In general, the clearance of mucus in the airways is achieved by the beating action of cilia inside the serous layer which is the primary means of removing inhaled particulates and airway debris from airways in healthy people. In this study, two types of mucus simulants are used in the experimental setup. Clearance distances of a teardrop shape simulant are measured for different velocities, slope angles and surfaces properties. On the obtained data by applying several genuine transformations we developed a multiple regression model that is able to predict clearance up to 86% accuracy. Simulations revealed several important data like direct relation between velocity and clearance and indirect relation between angle and clearance. Key Words- Mucus Simulant, Tracheal Model, Multivariate Regression Analysis, Linear Model, Simulation. 1. INTRODUCTION Coughing is necessary for removing inhaled particulates and airway debris from pulmonary airways. There are several studies in the literature for coughing experiments. In some studies, to simulate pulmonary airway, a tygon tube [7], a rigid channel [8], or an endotracheal tube [3-9] were used. Airflow limitation is due to excess mucus and the effectiveness of the mucociliary clearance depends on rheology and the quantity of mucus as well as activity of the cilia indicated by King [11]. Mucus simulants were prepared by cross-linking locust bean gum with sodium tetra borate, 12% to simulate more gel-like mucus with a low V/E (viscosity/elasticity) ratio [1-5]. Aliquots of 3% simulant resemble to normal lung mucus and the stimulant obtained by mixing a higher amount of sodium tetra-borax correlate with diseases such as cystic fibrosis, chronic bronchitis, and asthma [12]. Mucus clearance was investigated mechanically and experimentally (in vitro) for different air velocities, coughing angles and surfaces using different simulants in references before [3-9]. Other references will be explained in the text as appropriate. In this study, we have performed a multivariate regression analysis on the data set obtained from the tracheal model [4-10] where air flow was controlled by a 3-way