Aortic Stenosis
Theoretical and computational study of valvular or vascular stenosis. One of the goals of the study is to provide hemodynamic assessment of valvular stenosis by computationally determining the range of applicability of frequently used Gorlin's formula (and its improved versions) by the cardiologists to relate the cardiac output to the aortic valve area. [Professor Agarwal in collaboration with Professor R.D. Rifkin, Dr. M. Wendl, and Dr. D. Dooling of the School of Medicine]

Cardiac Dynamics
Measurement modeling and signal processing of abnormal dynamics in ventricular and atrial fibrillation. Analysis of arrhythmias as multi-degree-of-freedom nonlinear oscillations, using frequency-wavenumber spectra, correlation functions, and characteristic mode shapes of activity. Evaluation and improvement of defibrillation using principles of dynamics and simplified analytical and numerical models. [Professor Bayly in collaboration with Dr. R. E. Ideker at University of Alabama-Birmingham and Dr. R. B. Schuessler of the Department of Surgery, Washington University School of Medicine]

Cardiac Mechanics
Computational, experimental, and theoretical studies on mechanical properties of the intact heart. These include 3-D, non-linear finite element analysis of wall stress, the measurement of 3-D strain distributions in the intact heart using magnetic resonance imaging, and estimation of material properties of the intact ventricular wall. [Prof. Okamoto in collaboration with Dr. M. K. Pasque of the Department of Surgery and Dr. D. Li of the Mallinckrodt Institute of Radiology.]

Cardiovascular Mechanics
Patients with enlarged ascending aortas are at risk for life-threatening aortic dissection or rupture. These conditions can be understood as mechanical failures of the aortic wall caused by locally high stresses that exceed the strength of the tissue. In the normal aorta, the tearing strength of aortic tissue appears to greatly exceed the wall stresses under the extremes of physiologically attainable aortic pressures. In the dilated aorta, it is assumed that both abnormal wall characteristics and increased wall stresses contribute to the risk of dissection or rupture. However, the relative weights of these factors are not well understood. The main objective of this project is to study the mechanical properties of the aortic wall of patients with dilated aortas and to assess the contribution of these mechanical properties to the risk of dissection or rupture. [Prof. Okamoto in collaboration with Dr. Marc Moon, Department of Surgery, Washington University School of Medicine and Dr. Nicholas Kouchoukos, Missouri Baptist Medical Center, St. Louis, MO]

• Engineering Biomechanics Group
  

• Ramesh Agarwal
• Guy Genin - Cellular Mechanics, Attachment of Dissimilar Materials in Nature, Mechanics of Brain Injury
• Ruth Okamoto - Finite Elasticity, Mechanical Characterization of Bio-artificial Tissues, Mechanics of Dilated Human Ascending Aorta, Mechanical Properties of Mouse Aorta
• Michael Wendl