Madhavan L. Raghavan, Ph.D.
Primary Investigator
Affiliated with CCAD and BME @Iowa
Iowa City, Iowa 52242
Phone: 319-335-5704 (office)
Email: ml-raghavan@uiowa.edu
Dr. Madhavan Lakshmi Raghavan is an Associate Professor of Biomedical Engineering and Director of the Biomechanics of Soft Tissues (BioMOST) Division in the Center for Computer Aided Design at the University of Iowa. He is a teacher, research scientist and a mentor to student researchers in his lab. Yup, he likes his day job. But he likes even more, his nights and weekends at home with his wife and kids.
Born and brought up in Mettur Dam, Tamil Nadu, India, Prof. Raghavan obtained his bachelors degree in mechanical engineering at Coimbatore Institute of Technology, India (1992), and his Ph.D. in bionengineering at University of Pittsburgh (1998) where he served as a student researcher in the Division of Vascular Surgery under Prof. David Vorp - Engineering Professor. Following a two-year stint as a research scientist in the Division of Vascular Surgery at Dartmouth College under Dr. Mark Fillinger - Professor and Vascular Surgeon, he joined the BME faculty at University of Iowa in 2000.
Teaching at the Iowa College of Engineering is Prof. Raghavan's primary job. Courses he's taught include basic engineering topics such as engineering fundamentals, statics, dynamics and mechanics of deformable bodies, introductory BME courses such as Biomechanics, advanced biomechanics courses such as Cardiac and Vascular Mechanics and Advanced Bioloical Soft Tissue mechanics and the Biomedical Engineering senior design course. In 2010, he taught a study abroad course on healthcare technology in rural India with a group of Iowa students on location in South India.
Research and research mentorship is Prof. Raghavan's other job. He directs the BioMOST lab. The backbone of his lab are two research staff, five PhD candidates, four masters candidates and five undergraduate students. The lab's research is funded by NSF, NIH, and American Heart Association. The lab's research focuses on bringing to bear principles in experimental and computational engineeing mechanics and image processing to understand diagnose, and treat disease states in the cardiovascular and pulmonary system. Intrigued, but can't tell what all that exactly means, eh? You'll just have to browse the rest of this site to find out. On this main page, you will see general info on research projects. Detailed information on research projects may be seen in the student and staff pages.
Welcome to the BioMOST lab site!
PS: No! In the picture above, I am not demonstrating some novel mechanical tissue testing method we devised. I am making tea at my milk-stall during a cultural function using a traditional method used in India called the 5-feet tea.
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Aneurysms1992 - PresentAneurysm has been my focus area for the bettter part of the last twenty years. Aortic aneurysms over the entire period and cerebral aneurysms in the last decade. I was the first of a proud breed of aneurysm-focussed engineers who graduated from Dr. David Vorp's lab in Pittsburgh. So what exactly does an engineer have to do with aneurysms? You'd be surprised. These lesions are pressurized membranes that may rupture. And engineers like me bring to bear techniques in solid and fluid mechanics to improve our understanding of how aneurysms develop and better assess their severity or rupture risk. Not unlike the vey engineering art of assessing the failure risk of a boiler vessel or a 50 year-old bridge. Have we succeeded? Well... that's complicated. We've come some distance and we have much visibility in the field, but I can't say we've nailed it. There is no software that will tell if an aneurysm is going to rupture tomorrow. Not yet, at least. Want more details? See the pages of the lab's current staff and students that focus on this topic - Manasi Ramachandran, Rohini Retarekar, Benjamin Berkowitz, Benjamin Dickerhoff, Anna Hoppe, Aleko Nadareyshvili, Gaurav Sharda, and Tomithy Chung Courses I teach at Iowa that are enhanced by this research: Mechanics of deformable bodies, Biomechanics and Biomaterials, Cardiac and Vascular Mechanics, Advanced Biological Soft Tissue Mechanics |
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Cardiovascular implants and devices2002 - PresentThe urge to design, build and tinker defines the quintessential engineer. Even the ones adultered by biology and medicine such as yours truly :-) Luckily there is a whole field to sate that thirst - Medical devices. My lab's interests are:
Want more details? See the pages of the lab's current staff and students that focus on this topic - Kathleen Lin, Chaid Schwarz, Aleko Nadareyshvili, Anna Hoppe and Benjamin Dickerhoff Courses I teach at Iowa that are enhanced by this research: Biomechanics and Biomaterials, Cardiac and Vascular Mechanics, BME Senior design I and II |
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Pulmonary mechanics2007 - PresentIowa is the lion's den for lung imaging research. In collaboration with colleagues in imaging and image processing (Professors Joseph Reinhardt and Gary Christensen), my lab uses principles in engineering mechanics to better characterize some aspects of lung function and seeks to use this information to diagnose early onset of lung disease in patients. Specific research involves development of novel measures of the expansion of the lung during breathing that can shed light on how the lung expands and how this relates to the chest cavity and the diaphragm that it is in contact with. Want more details? See the page of a graduate student in the lab who focuses on this topic - Ryan Amelon Courses I teach at Iowa that are enhanced by this research: Advanced Biological Soft Tissue Mechanics |
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Mechanical testing of biological soft tissuesThe human body is made of mostly soft tissues (as opposed to hard tissues like bone). Skin, heart, brain, blood vessels, intestine, stomach, kidney, liver, lung, you name it. Some among these perform essential mechanical functions - that is force, constraint and motion are a part of what they do. Think the beating heart and the blood pressure involved, the expanding lungs and the pleural pressure involved, the intestines and their contractions, etc. If we really want to understand their function, we need to understand their mechanical properties. But biological tissues aren't exactly your everyday elastic bands. They shear and stretch in funny ways. And they change their composition under various situations resulting in funny alterations. How do we test these? We need special ways of testing them. Some interesting research in my lab on this generic area are:
Want more details? See the page of an undergraduate student in the lab who focuses on this topic - Andrew Jennings Courses I teach at Iowa that are enhanced by this research: Biomechanics and Biomaterials, Cardiac and Vascular Mechanics, Advanced Biological Soft Tissue Mechanics |
- Raghavan ML, Lin K, Ramachandran M, Nadareshvili A, Lu J, "Planar radial extension for constitutive modeling of anisotropic biological soft tissues", International Journal of structural changes in solids (accepted for publication), 2011
- Zhao X, Raghavan ML, Lu J, "Identifying heterogeneous anisotropic properties in cerebral aneurysms: a pointwise approach", Biomech Model Mechanobiol., in press, 2010
- Zhou X, Raghavan ML, Harbaugh RE, Lu J , "Patient-Specific Wall Stress Analysis in Cerebral Aneurysms Using Inverse Shell Model", Ann Biomed Eng, 38(2):478-89, 2010
- Kratzberg JA, Golzarian J, Raghavan ML, "Role of graft oversizing in the fixation strength of barbed endovascular grafts", Journal of Vascular Surgery, 49(6):1543-53, 2009
- Cai ZJ, Bai EW, McCabe R, Zerhouni M, Wang G, Raghavan ML, Kratzberg J, "A dynamic arterial tree phantom for studies of bolus chasing CT angiography", International Journal of Biomedical Engineering and Technology, 4(10):88-100, 2009
- Kratzberg JA, Walker PJ, Rikkers E, and Raghavan ML, "The effect of proteolytic treatment on plastic deformation of porcine aortic tissue", Journal of the Mechanical Behavior of Biomedical Materials, 2[1]:65-72, 2009.
- Lu J, Zhou X, Raghavan ML., "Inverse method of stress analysis for cerebral aneurysms", Biomech Model Mechanobiol, 7(6):477-86, 2008.
- Zhang J, Fletcher JG, Vrtiska TJ, Manduca A, Thompson JL, Raghavan ML, Wentz RJ, McCollough CH, "Large-vessel distensibility measurement with electrocardiographically gated multidetector CT: phantom study and initial experience", Radiology, 245(1):258-66, 2007
- Lu J, Zhou X, Raghavan ML, "Inverse Elastostatic Stress Analysis in Pre-deformed Biological Structures: Demonstration Using Abdominal Aortic Aneurysms", Journal of Biomechanics, 40(3):693-6, 2007
- Ma, B, Lu J, Harbaugh RE, Raghavan ML, "Nonlinear Anisotropic Stress Analysis of Anatomically Realistic Cerebral Aneurysms", Journal of Biomechanical Engineering, 129(1):88-96, 2007
- Lu J, Zhou X, Raghavan ML, "Computational Method for Inverse Elastostatics in Anisotropic Hyperelastic Solids", Journal for Numerical Methods in Engineering, 69: 1239-61, 2007
- Raghavan, M.L., J. Kratzberg, E.M. Castro de Tolosa, M.M. Hanaoka, P. Walker, and E.S. da Silva, "Regional distribution of wall thickness and failure properties of human abdominal aortic aneurysm", Journal of Biomechanics, 39(16):3010-6, 2006.
- Raghavan ML, Ma B, Fillinger MF, "Non-invasive determination of zero-pressure geometry of arterial aneurysms", Annals of Biomedical Engineering, 34(9):1414-9, 2006
- Raghavan, M.L., M.F. Fillinger, S.P. Marra, B.P. Naegelein, and F.E. Kennedy, "Automated methodology for determination of stress distribution in human abdominal aortic aneurysm", ASME Journal of Biomechanical Engineering, 127(5):868-71, 2005 Oct
- Raghavan ML, Kratzberg JA, Golzarian J., "Introduction to biomechanics related to endovascular repair of abdominal aortic aneurysm", Techniques in Vascular Interventional Radiology, 8(1):50-5, 2005 Mar.
- Raghavan, M.L., B. Ma, and R.E. Harbaugh, "Quantified Aneurysm Shape and Rupture Risk", Journal of Neurosurgery, 102(2): p. 355-62, 2005.
- Kratzberg JL, S. Greifzu, K. Larson, J. Dittman, M. McCormick, M. Keller, M.L. Raghavan, "Fabrication of a patient-specific replica of abdominal aortic aneurysm with realistic compliance and translucency", International Journal of Cardiovascular Medicine, 5(1), 33-38, 2005.
- Ma B, Harbaugh RE, and Raghavan ML, "Three-dimensional Geometric characterization of cerebral aneurysms", Annals of Biomedical Engineering, 3(2): 264-73, 2004 Feb.
- Raghavan ML, Trivedi S, Nagaraj A, McPherson DD, Chandran KB, "Three-Dimensional Finite Element Analysis of Residual Stress in Arteries", Annals of Biomedical Engineering, 3(2): 257-63, 2004 Feb.
- Fillinger MF. Marra SP. Raghavan ML. Kennedy FE, "Prediction of rupture risk in abdominal aortic aneurysm during observation: wall stress versus diameter", Journal of Vascular Surgery. 37(4):724-32, 2003
- Fillinger, MF, Raghavan ML, Marra SP, Cronenwett JL, Kennedy FE, "In Vivo Analysis of Mechanical Wall Stress and AAA Rupture Risk", Journal of Vascular Surgery, 36(3): 589-597, 2002
- Raghavan ML, Vorp DA. Toward a biomechanical tool to evaluate rupture potential of abdominal aortic aneurysm: identification of a finite strain constitutive model and evaluation of its applicability. Journal of Biomechanics. 33(4): 475-82, Apr 2000
- Raghavan ML, Vorp DA, Federle MP, Makaroun MS, Webster MW. Wall stress distribution on three-dimensionally reconstructed models of human abdominal aortic aneurysm. Journal of Vascular Surgery. 31(4): 760-9, Apr 2000
- Sacks MS, Vorp DA, Raghavan ML, Federle MP, Webster MW. In vivo three-dimensional surface geometry of abdominal aortic aneurysms. Annals of Biomedical Engineering. 27(4): 469-79, 1999
- Vorp DA, Raghavan ML, Webster MW. Mechanical wall stress in abdominal aortic aneurysm: influence of diameter and asymmetry. Journal of Vascular Surgery. 27(4): 632-9, Apr 1998
- Raghavan ML, Webster MW, Vorp DA. Ex vivo biomechanical behavior of abdominal aortic aneurysm: assessment using a new mathematical model. Annals of Biomedical Engineering. 24(5): 573-82, 1996
- Vorp DA, Raghavan ML, Muluk SC, Makaroun MS, Steed DL, Shapiro R, Webster MW. Wall strength and stiffness of aneurysmal and nonaneurysmal abdominal aorta. Annals of the New York Academy of Sciences. 800: 274-6, Nov 1996
- Vorp DA, Raghavan ML, Borovetz HS, Greisler HP, Webster MW. Modeling the transmural stress distribution during healing of bioresorbable vascular prostheses. Annals of Biomedical Engineering. 23(2): 178-88, 1995