Prof. David Isaacson

This project is a collaboration between Center for Integrative Biomedical Computing and Prof. David Isaacson of the Mathematics Department, and the Electrical Impedance Imaging Laboratory, at Rensselaer Polytechnic Institute (RPI) in Troy N.Y. Electrical Impedance Imaging, and more specifically its tomographic variant Electrical Impedance Tomography (EIT), is a relatively cheap, safe, and non-invasive method to image functional and metabolic properties of the body. The approach taken by the RPI laboratory is to inject current from a set of electrodes on the surface of the region to be imaged, and measure the resulting voltage. The currents and voltages are then fed into an imaging algorithm which reconstructs the conductivity (or more generally admittance or impedance) map of the volume being interrogated. EIT has been applied to a number of diagnostic problems as well as a precursor to inverse bioelectric problems.

Dr. Andrew McCulloch

The heart is a complex three-dimensional structure in which the biophysics of the cardiac action potential, and the mechanics of muscle cell contraction, interact to produce efficiently coordinated ventricular pumping. The aim of Dr. McCulloch's research is to develop and experimentally validate an accurate three-dimensional model of regional cardiac mechanics and electrophysiology and their mutual interactions. Three-dimensional finite element (FE) models of the heart are being developed by Dr. McCulloch's research group that include accurate descriptions of ventricular anatomy and myofiber architecture; the resting and contractile mechanical properties of myocardium; and the cellular dynamics of action potential propagation. To analyze the biological basis of electromechanical interactions in the intact heart, theoretical models of cardiac excitation-contraction coupling and mechanoelectric feedback are being incorporated by researchers into the continuum framework. The coupled models involve large-scale computations and are implemented on the IBM/SP Teraflop parallel supercomputer, Blue Horizon, by exploiting the structural parallelism of the underlying physical problem. These models will be used to investigate basic questions such as how stretch activated ion channels affect conduction patterns in the intact heart, and how altered pacing sequences affect ventricular pumping efficiency.

Prof. Charles DiMarzio and Dr. Milind Rajadhyaksha

Prof. DiMarzio is the Director of the Optical Sciences Laboratory in the Electrical and Computer Engineering Department at Northeastern University. Dr. Rajadhyaksha is a Research Scientist working with Prof. DiMarzio and also with the Dermatology Department of Memorial Sloan Kettering Cancer Center in New York. Prof. DiMarzio's primary interest is in development of new microscopes; he was the PI on a $750,000 award from the Keck Foundation to develop an integrated multi-modality microscope that is now functioning. Dr. Rajadhyaksha is the PI on the NIBIB grant cited above and an investigator on the NCI grant, and his primary interest is in the development of new, portable confocal microscopes and associated algorithms for detection of skin cancer at the bedside or in the clinic.

Dr. Dirar Khoury

Heart rhythm disorders (arrhythmias) result in significant morbidity and mortality. Due to limitations in present catheter mapping techniques, brief, chaotic, or complex arrhythmias such as atrial fibrillation and ventricular tachycardia cannot be mapped adequately, resulting in unsuccessful elimination of the arrhythmia. Selecting appropriate pharmacological or non-pharmacological therapies to manage cardiac arrhythmias is contingent on developing mapping techniques that identify mechanisms of arrhythmias, localize their sites of origin with respect to underlying cardiac anatomy, and elucidate effects of therapy.