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CardioWave(redirected from User.CardioWave) In conjunction with the Electrophysiology Group at Duke University, we are working on computer simulations of the flow of electrical current in the heart. Through more powerful computer modelling techniques, we can gain a better understanding of arrhythmias and tachycardias (irregular heart beats). By understanding the electrical and cellular mechanisms which create and sustain these life-threatening rhythms, we hope that researchers can then propose newer, more effective, and safer therapies. The mechanical contraction of the heart is preceded by a sweep of electrical activity. This electrical activity, or electrical wavefront, is initiated by "pacemaker" cells in various regions of the heart (modified by signals from the central nervous system) and is conducted throughout the heart muscle by the cells themselves. Under normal conditions, this wavefront remains fairly well connected as it propagates across the heart. The wavefront starts at the bottom of the heart and propagates upward until it collides with the insulating A-V groove. This causes one strong, coordinated mechanical contraction of the heart, thereby pumping blood to the rest of the body. For a number of reasons, this wavefront may become fragmented - external factors such as electrical shocks can cause such fragmentation, but more likely it is the result of dead tissue in the heart (infarcted regions possibly caused by clogged arteries and the like). When the wavefront is fragmented, the individual "wavelets" may not remain coordinated, and hence the electrical conduction problems can lead to a loss of mechanical pumping ability (ie. less blood gets pushed to the rest of the body and the person may begin to feel tired). In particularly bad cases, it may lead to "re-entry" and fibrillation. In re-entry, the wavelets never collide with the A-V groove and hence do not die out. Instead, the wavelets continue propagating across the tissue, thereby disrupting the following heart beats as well. The extreme case of fibrillation, a so called "heart attack", may have dozens of these wavelets circulating through the tissue - the end result of which is a complete lack of mechanical pumping, and hence no blood gets to the rest of the body. Using the BidomainEquations, we can simulate the flow of electrical current on computers. These simulations can then give the researchers insight into the mechanisms that generate and sustain arrhythmias. Such simulations obviously help limit the amount of animal testing that needs be done, but also can help provide more detailed results than are otherwise possible with experimental procedures. For example, the computer simulations can provide information about ionic flows through the membrane, information which is extremely difficult or impossible to obtain during a real experiment. However, these simulations can take many hours of machine time to compute. Our research is aimed at reducing this computational time through the use of parallel supercomputers. The current work involves the creation of a modular simulation system which researchers can use to investigate the electrical properties of the heart. The modular approach allows individual researchers to "mix-and-match" parts to tailor the simulation executable to their specific objectives. It also allows researchers to focus more closely on their own area of expertise, reducing their need to become expert parallel computer programmers. There are several CardioWave components:
See also: ProgramModularity |