Quantifying the effect of uncertainty in input parameters in a simplified bidomain model of partial thickness ischaemia

Reduced blood flow in the coronary arteries can lead to damaged heart tissue (myocardial ischaemia). Although one method for detecting myocardial ischaemia involves changes in the ST segment of the electrocardiogram, the relationship between these changes and subendocardial ischaemia is not fully understood. In this study, we modelled ST-segment epicardial potentials in a slab model of cardiac ventricular tissue, with a central ischaemic region, using the bidomain model, which considers conduction longitudinal, transverse and normal to the cardiac fibres. We systematically quantified the effect of uncertainty on the input parameters, fibre rotation angle, ischaemic depth, blood conductivity and six bidomain conductivities, on outputs that characterise the epicardial potential distribution. We found that three typical types of epicardial potential distributions (one minimum over the central ischaemic region, a tripole of minima, and two minima flanking a central maximum) could all occur for a wide range of ischaemic depths. In addition, the positions of the minima were affected by both the fibre rotation angle and the ischaemic depth, but not by changes in the conductivity values. We also showed that the magnitude of ST depression is affected only by changes in the longitudinal and normal conductivities, but not by the transverse conductivities

Transient Response of a Hollow Cylindrical-Cross-Section Solid Sensible Heat: Storage Unit- Single Fluid

plosion which have been interpreted in terms of the kinetic theory of nucleation can likewise be viewed in terms of film boiling destabilization with attendant fine scale fragmentation of the hot material. Vol. 77, No. 23, 1973, pp. 2730-2736 26 Cronenberg, A. W., Benz, R., to be published, Advances in Nuclear Science and Technology, 1978. 27 Anderson, R. P., Armstrong, D. R., ASME Meeting on Nuclear Reactor Safety Heat Transfer, Atlanta, Ga., Nov. 1977. 28 Henry, R. E., Fauske, H. K., McUmber, L. M., Proceedings of ANS Conference on Fast Reactor Safety, Chicago, 111. (Oct. 1976). Conclusions 29 Fauske, H. K., Nuclear Science and Engineering, Vol. 51, 1973, pp. 95-101. 30 Fauske, H. K., Reactor Technology, Vol. 15, No. 4, 1972-1973 3

Mathematical Modeling and Simulation of Ventricular Activation Sequences: Implications for Cardiac Resynchronization Therapy

Next to clinical and experimental research, mathematical modeling plays a crucial role in medicine. Biomedical research takes place on many different levels, from molecules to the whole organism. Due to the complexity of biological systems, the interactions between components are often difficult or impossible to understand without the help of mathematical models. Mathematical models of cardiac electrophysiology have made a tremendous progress since the first numerical ECG simulations in the 1960s. This paper briefly reviews the development of this field and discusses some example cases where models have helped us forward, emphasizing applications that are relevant for the study of heart failure and cardiac resynchronization therapy

Experimental heat transfer distribution on the SNAP 10A reactor

Heating distributions have been obtained for the SNAP 10A reactor by means of a thermal paint technique in the Rhodes and Bloxsom 60 in. hypersonic wind tunnel. Data and correlations are presented only for those reactor components where the ratio of the local heat transfer to that on the stagnation point of the calibration sphere was found to be independent of tunnel conditions. It is shown that these heating distributions can be applied directly to reentry conditions provided the thermally painted and the bare reactor surfaces are both catalytic to atom recombination

A model to explain composition effects in smelt-water explosions

"April 1988.""This manuscript is based on results obtained in IPC research and has been submitted for consideration for publication in Chemical Engineering Communications.