Int. J. Biomedical Engineering and Technology, Vol. 4, No. 3, 2010 195 Copyright © 2010 Inderscience Enterprises Ltd. Equivalent fluid model for CSF and SAS trabeculae using head/brain damping Mohamad Zoghi-Moghadam Xilinx Inc., San Jose, California 95124, USA E-mail: mohamadz@xilinx.com E-mail: Zog2725@me.ccny.cuny.edu Ali M. Sadegh* Department of Mechanical Engineering, Steinam Hall Room 256, The City College of CUNY, Convent Avenue and 140th Street, New York, NY 10031, USA Fax: 212-650-6640 E-mail: Sadegh@ccny.cuny.edu *Corresponding author Abstract: The focus of this study is to quantify the damping characteristics of the Subarachnoid Space (SAS) trabeculae and to propose an equivalent viscous fluid, which could be employed as a representative of the CSF and the trabeculae. The experimental results were used and a damping model for the system of trabeculae was proposed. The effective viscosity of the equivalent viscous fluid, representing the CSF and the trabeculae, was then calculated. A 3-D fluid model of the SAS region including the fluid and without any trabeculae was created. Using the effective viscosity, the fluid model was validated with the experimental results. It was concluded that the proposed viscous fluid greatly simplify the head/brain models. Keywords: head impact; damping model; CSF and SAS fluid model; fluid solid interaction in head. Reference to this paper should be made as follows: Zoghi-Moghadam, M. and Sadegh, A.M. (2010) ‘Equivalent fluid model for CSF and SAS trabeculae using head/brain damping’, Int. J. Biomedical Engineering and Technology, Vol. 4, No. 3, pp.195–210. Biographical notes: Mohamad Zoghi-Moghadam received his PhD and MS from the Department of Mechanical Engineering of The City College of the City University of New York. He is a member of the American Society of Mechanical Engineers. He received his BSME from Sharif University of Technology, Tehran, Iran, in 1998, and then worked as the Technical Manager of Kalaye-Pump Company, manufacturing petrochemical pumps from 1998 to 2000, in Tehran. He has also been an Industry Consultant on issues relating to lift truck design. Currently, he is working as a System Engineer at Xilinx Inc. in San Jose California, USA. Ali M. Sadegh is a Professor of Mechanical Engineering, Director of the Center for Advanced Engineering Design and Development and former Chairman