Ponangi Udaya Prashant, Nagaraj Balasubramanya

Abstract: Background: There are different experimental models avialable for generating pulsatile flow in laboratory and study their heamodynamic effects on blood vessels. We aim to produce a novel pulsatile flow generator utilizing a large collapsible rubber bladder and the phenomenon of fluid structure interactions occurring in a specially designed flexible tube arrangement. Mehtods: Water enters from a reservoir above into a large collapsible bladder made of rubber which opens into ‘U’ shaped tube made of flexible material and held by non rigid structures. As liquid starts flowing the distal end of collapsible bladder collapses under the negative atmospheric pressure generated inside closing the mouth of ‘U’ shaped tube and produces pulsatile flow. Resuts: The frequency of pulsations, pressure fluctuations and velocity profile resemble that of in vivo blood flow. As the flow entering into collapsible bladder increases the frequency of pulsatile flow decreases and also when height of the collapsible bladder from the ground was changed. The whole cycle of alternate collapse/expansion of collapsible bladder with generation of pulsatile flow continue indefinitely as long as there is enough water in reservoir and vertical gradient to sustain the flow. Conclusions: The pulsatile flow so produced has many of the characteristics of physiological blood flow and can be used to study mechanisms of various cardiovascular diseases in laboratory.

Keywords: Collapsible Tubes; Buckling; Pulsatile Flow Generator; Unsteady Flow; Fluid Structure Interactions

Cite this paper: Prashant, P. and Balasubramanya, N. (2010) A pilot study of a novel pulsatile flow generator using large collapsible bladder. Journal of Biomedical Science and Engineering, 3, 677-683. doi: 10.4236/jbise.2010.37092.

References

[1]   Afshin, A.-B., Mohammad, T.-S., Nasser, F., et al. (2008) A new system to analyze pulsatile flow characteristics in elastic tubes for hemodynamic applications. American Journal of Applied Sciences, 5(12), 1730-1736.

[2]   Chatzizisis, Y.S. and Giannoglou, G.D. (2006) Pulsatile flow: A critical modulator of the natural history of ath- erosclerosis. Electronic Publication, 67(2), 338-340.

[3]   Finol, E.A. and Amon, C.H. (2001) Blood flow in abdominal aortic aneurysms: Pulsatile flow hemodynamics. Journal of Biomechanical Engineering, 123(5), 474-484.

[4]   Law, Y.F., Cobbold, R.S.C., et al. (1987) Computer-con- trolled pulsatile pump system for physiological flow si- mulation. Medical & Biological Engineering & Computing, 25(5), 590-595.

[5]   Petersen, J.N. (1984) Digitally controlled system for reproducing blood flow waveforms in vitro. Medical and Biological Engineering and Computing, 22(3), 277-280.

[6]   Eriksson, A., Persson, H.W. and Lindstrom, K. (2000) A computer-controlled arbitrary flow wave form generator for physiological studies. Review of Scientific Instruments, 71(1), 235-242.

[7]   Holdswoth, D.W., Rickey, D.W., et al. (1991) “Computer-controlled positive pump for physiological flow simulation,” Medical & Biological Engineering & Computing, 29(4), 565-570.

[8]   Kamm, R.D. and Shapiro, A.H. (1979) Unsteady flow in a collapsible tube subjected to external pressure or body forces, Journal of Fluid Mechanics, 95(1), 1-78.

[9]   Heil, M. and Jensen, O.E. (2003) Flows in deformable tubes and channels -- Theoretical models and biological applications. Chapter 2 of: flow in collapsible tubes and past other highly compliant boundaries. Pedley, T.J. and Carpenter, P.W., Eds., Kluwer, Dordrecht, Netherlands Heil, 15-50.

[10]   Heil, M. (1996) The stability of cylindrical shells conveying viscous flow. Journal of Fluids and Structures, 10(2), 173-196.

[11]   Heil, M. and Pedley, T.J. (1996) Large post-buckling deformations of cylindrical shells conveying viscous flow. Journal of Fluids and Structures, 10(6), 565-599.

[12]   Heil, M. (1998) Stokes flow in an elastic tube -- A large- displacement fluid-structure interaction problem. The International Journal for Numerical Methods in Fluids, 28(2), 243-265.

[13]   Tijsseling, A. (2007) Water hammer with fluid-structure interaction in thick-walled pipes. Computers and Structures, 85(11-14), 844-851.

[14]   Heinsbroek, A.G.T.J. and Tijsseling, A.S. (1994) The influence of support rigidity on waterhammer pressures and pipe stresses. Proceedings of the Second International Conference on Water Pipeline System and BHR Group, Edinburgh, 17-30.

[15]   Wiggert, D.C. and Tijsseling, A. S. (2001) Fluid transients and fluid-structure interaction in flexible liquid filled piping. ASME, 455-481.

[16]   Tijsseling, A.S. and Heinsbroek. A.G.T.J. (1999) The influence of bend motion on waterhammer pressures and pipe stresses. Proceedings of the 3rd ASME & JSME Joint Fluids Engineering Conference, Symposium S-290 Water Hammer (Editor JCP Liou), San Francisco, July 1999, ASME FED, 248, Paper FEDSM99-6907.

[17]   Kumar, D.S. (2010) Fluid mechanics and fluid power engineering. S. K. Kataria & Sons Publishers and Distributors, New Delhi, Chapter 9.

[18]   Ahmad A. and Ali R.K. (2008) Investigation of the junction coupling due to various types of the discrete points in a piping system. The 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, India.

[19]   Knapp, Y., Bertrand, E. and Mouret, F. (2003) 2D-PIV measurements of the pulsatile flow in a left heart simulator. Proceedings of PSFVIP-4, Chamonix, F4082.

[20]   Wang, W.X. and Christopher D.B. (2007) Effects of collapsible-tube-induced pulsation vigour on membrane filtration performance. Journal of Membrane Science, 288 (1-2), 298-306.