arXiv:1111.5645v1 [physics.bio-ph] 23 Nov 2011 Dynamic Elastic Properties of Human Bronchial Airway Tissues J.-Y. Wang a , P. Mesquida a,b , P. Pallai c , C. J. Corrigan c , T. H. Lee c jauyi.wang@kcl.ac.uk, patrick.mesquida@kcl.ac.uk a Division of Engineering, King’s College London, Strand, London WC2R 2LS, UK b Department of Physics, King’s College London, Strand, London WC2R 2LS, UK c Asthma, Allergy and Lung Biology Division, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King’s College London, Guy’s Hospital, London SE1 9RT, UK November 20, 2011 Abstract Young’s Modulus and dynamic force moduli were measured on human bronchial airway tissues by compression. A simple and low-cost system for measuring the tensile-strengh of soft bio-materials has been built for this study. The force-distance measurements were undertaken on the dissected bronchial airway walls, cartilages and mucosa from the surgery-removed lungs donated by lung cancer patients with COPD. Young’s modulus is estimated from the initial slope of unloading force-displacement curve and the dynamic force moduli (storage and loss) are measured at low frequency (from 3 to 45 Hz). All the samples were preserved in the PBS solution at room temperature and the measurements were perfomed within 4 hours after surgery. Young’s modulus of the human bronchial airway walls are fond ranged between 0.17 and 1.65MPa, ranged between 0.25 to 1.96MPa for cartilages, and between 0.02 to 0.28MPa for mucosa. The storage mod- ulus are found varying 0.10MPa with frequency while the loss modulus are found increasing from 0.08 to 0.35 MPa with frequency. The frequency- dependent dynamic force moduli are also compared with different strain rates. 1 Introduction Ariway diseases such as asthma are related to the airway wall elasticity. The elastical properties of lung tissue are important to determine the mechanical behoviour of lungs [1]. Over the past few decades, dynamic measurments on the respiratory gas pressure, volume, and flow have been applied on clinical diagonis for understanding the lung mechanics such as spirometry and forced-oscillation technique [2]. The lung resistance R r and elastance E r are determined by the 1