L. Tung. A bi-domain model for describing ischemic myocardial D-C potentials. PhD thesis, MIT, Cambridge, MA, 1978.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... account realistic fiber geometry, anisotropy of cardiac conductivities, detailed membrane properties, microscopic tissue structure, and the inhomogeneous nature of myocardium [46, 52, 54, 60] A model that can account for these effects, with a proper choice of parameters, is the bidomain model [31, 62], a system of reaction diffusion partial differential equations (PDE s) coupled with a stiff ordinary differential equation (ODE) system representing cell membrane dynamics. The bi domain model consists of the equations for the intra and extracellular potentials, Phi i and Phi e , coupled ....

....relationship of the second reaction to the synchronization of fine data with coarse. We will discussion the reaction steps in this section. The linear algebra will be discussed in section 5. 39 4.5. 1 Initial Operator Split Reaction In practical models of electrical wave propagation in the heart [31, 62], there are typically several to dozens of reactions to be integrated. These may involve significant numerical work, due both to the nonlinear functions involved and the stiffness of the reactions. As a result, it would be desirable to concentrate the numerical work for these reactions where the ....

L. Tung. A bi-domain model for describing ischemic myocardial D-C potentials. PhD thesis, MIT, Cambridge, MA, 1978.

....to various levels of detail allowing the model to be tailored to suit the performance capabilities of the host machine. Figure 1 Einthoven s Triangle and the cardiac conduction system. 2. PREVIOUS WORK Most cardiac simulation systems are based upon an interpretation of the bidomain model [Por00, Sal95, Plo89, Tun78], which separates the myocardial volume into an intracellular and extracellular space, separated by a membrane. Perhaps the most advanced cardiac model to date has been that produced by the Cardiome Project, a subproject of the Physiome Permission to make digital or hard copies of all or part of ....

Tung, L., A bidomain model for describing ischemic myocardial dc potentials, Ph.D., Massachusetts Institute of Technology, 1978.

....with the primary goal of this study, our research focuses on the extent to which electroporation alters the cathode anode make and break phenomena associated with the defibrillation shock. 2 Model Description We model a two dimensional slice of myocardium using the bidomain representation [21]. Thus, the intracellular, Phi i (mV ) and extracellular, Phi e , potentials, as well as the trans2 membrane potential, Vm = Phi i Gamma Phi e , are defined everywhere in the cardiac domain Omega Gamma To describe the ionic current I ion (A=cm 2 ) we use Drouhard Roberge modification ....

L Tung. A Bidomain Model for Describing Ischemic Myocardial D.C. Potentials. PhD thesis, Massachusetts Institute of Technology, Cambridge, 1978.

....the properties of existing cell membrane models and make necessary modifications to the model of our choice (see sections 3.3.1 and 3.3.2) in order to be able to simulate the membrane behavior under strong electric shocks. We briefly introduce the continuous bidomain model of cardiac tissue [43, 44, 45]. The bidomain model views the myocardium as two interconnected domains, extracellular and intracellular, with different conductivity properties. All the simulations are conducted in two dimensions, which limits our ability to represent the heart geometry accurately. Still, by introducing non zero ....

....the surface to volume ratio of the myocardium (i.e. the ratio of total membrane area to total tissue volume) and oe i x and oe i y are the longitudinal and transverse conductivities. This monodomain model assumed that the extracellular space was grounded. A new approach, the bidomain model [43, 44, 45], has gained popularity, by eliminating this restrictive assumption. In this model, the tissue is represented as two coupled, continuous domains. The extracellular and the intracellular domains are thought to occupy the whole myocardium. Therefore, the intracellular Phi i and extracellular Phi e ....

Tung, L (1978). A Bidomain Model for Describing Ischemic Myocardial D.C. Potentials. PhD thesis, Massachusetts Institute of Technology, Cambridge.

....action potential from propagating forever in the heart. 2.2 The bidomain model The inhomogeneous structure of cardiac tissue complicates the modelling of its electrical behaviour. Decisions must be made regarding the amount of discrete structural detail to include in the model. The bidomain model[42, 68, 71, 123] addresses this problem by spatial averaging of the discrete structure to yield a continuum representation. In so doing it limits itself to describing phenomena whose length scale exceed the dimensions of a single cell. However this simplification leads to a partial differential equation ....

....bidomain model has also been used with a representation of a bath and a special boundary condition at the bath tissue interface. In this case, the main region of interest is around the bath tissue interface, so the boundary condition and its effects play a more central role in the computation. Tung[123] proposed that at the fluid tissue interface, the bath potential, OE o , must be continuous with the interstitial potential, OE e , and the corresponding currents should be continuous, i.e. OE e = OE o ; oe e rOE e ) Delta n = oe o rOE o ) Delta n (2:13) where oe o is the bath conductivity ....

L. Tung. A bidomain model for describing ischemic myocardial D-C potentials. PhD thesis, Massachusetts Institute of Technology, 1978.

No context found.

L. Tung. A bi-domain model for describing ischemic myocardial D-C potentials. PhD thesis, MIT, Cambridge, MA, 1978.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC