Simulation Of Cardiovascular System Research Articles

Simulation of normal cardiovascular system and severe aortic valve stenosis using equivalent electronic model

In this study, we have designed an analog circuit model of the cardiovascular system that is able to simulate normal condition and cardiovascular diseases, such as mitral stenosis, aortic stenosis, and hypertension. Especially we focused on severe aortic stenosis, because it is one of the causes of sudden death in asymptomatic patients. In this study, we aim to investigate the simulation of the cardiovascular system using an electronic circuit model under normal and especially severe aortic valve stenosis conditions. The Westkessel model including RLC pi-segments is chosen in order to simulate both systemic and pulmonary circulation. The left and right heart is represented by trapezoidal shape stiffnesses. Aortic capacitance and aortic valve characteristics are chosen nonlinear. Severe aortic stenosis is implemented by changing the value of the serial resistance to the aortic valve. MATLAB software program is used for the model implementation. The results for normal conditions of the given electrical model are similar to the normal cardiovascular physiology. As a result of simulation, a remarkable increase of the left ventricle systolic blood pressure and aortic mean pressure gradient, and decrease of aortic systolic blood pressure are observed in severe aortic valve stenosis. In conclusion, our model is effective and available for simulating normal cardiac conditions and cardiovascular diseases, especially severe aortic stenosis.

GRID SIMULATION SERVICES FOR THE MEDICAL COMMUNITY

The first part of this paper presents a selection of medical simulation applications, including image reconstruction, near-real-time registration for neuro-surgery, enhanced dose distribution calculation for radiotherapy, inhaled drug delivery prediction, plastic surgery planning and cardio-vascular system simulation. The latter two topics are discussed in some detail. In the second part, we show how such services can be made available to the clinical practitioner using grid technology. We discuss the developments made and the experience gained during the EU project GEMSS, which provides reliable, efficient, secure and lawful medical grid services.

Computer assisted instruction for therapy of heart failure based on simulation of cardiovascular system

Adequate treatment of cardiac failure should reflect both clinical rules and quantitative evaluation of hemodynamics. For the latter we assumed an extensive model of heart and vessels: For the left and right ventricles the EMAX models were assumed with the parameters of contractilities and diastolic compliances. The model of the vessels was composed of systemic and pulmonary vascular networks with arterial, capillary and venous segments. Heart failure of various types was simulated by the model and the optimal therapeutic regimen was formulated. The cardiovasular parameters of patients with heart failure could be esimated from the hemodynamic measurements through the model and the optimal therapy was computed with the technique of nonlinear programming.The simulation thechnique was incorporated in the computer assisted instruction system based on the clinical emirical rules. The program was written with TURBO PASCAL for a microcomputer with CPU 80286. The response time was within a tolerable range for use in the clinical practice.

Briefly Now, More Later

I think I can best let Vince Rideout tell it for himself: "When I was a new assistant professor (about 1948) in the EE Department of the University of Wisconsin, struggling to introduce our first auto matic control course, my chairman, Harold A. Peterson, got me interested in the idea of using some of the new electronic analog computers in connection with this work. We purchased some Philbrick 'boxes,' and have been simulating ever since. During the summer of 1951 I worked for Boeing in Seattle and got some further familiarity with the use of analog computers there, and even more as a consultant for Allis Chalmers from 1956 on. In 1954 when I went to Bangalore.. India for a year at the Indian Institute of Science, I took along some plug-in op-amps., etc. and built India's first analog computer there. About 1964 I began to work on cardiovascular system simulation, and continue to do so. Also, about 1965 I was instrumental in getting a large hybrid instal lation at Wisconsin, and was director of our hybrid laboratory until 1972, when I left to become depart ment chairman. Since leaving the chairmanship a year ago, I have become interested in two new fields of research-array computer design and large-scale socioeconomic modeling."

Cardiovascular system simulation in biomedical engineering education.

A number of complex cardiovascular system models have been developed at the University of Wisconsin largely as a result of bioengineering thesis work carried on in the Department of Electrical Engineering, using a large hybrid computer. Other work in modeling includes parameter estimation study and the development of new methods of modeling. This work has been carried out in collaboration with research workers in Medical and Life Sciences Departments at Wisconsin.