The electrodynamical rigorous solution of Maxwells equations related to the microwave pulse propagation inside a three-dimension heart model is presented here. The boundary problem was solved by using the singular integral equations method. The carrier microwave frequency is 2.45 GHz. The pulse durations were always equal to 20 ms. The modulating signals are triangular video pulses with the on-off time ratio equal to 5 and 100. The model heart was limited by a non-coordinate shape surface and it consisted of two different size cavities. The heart cavities were schematic images of the left and right atriums and ventricles. In our calculations the cavities were filled with blood with the permittivity epsilon(2) = 58 - i19 and the walls of the heart consisted of myocardium tissue with the permittivity epsilon(1) = 55 - i17. Microwave electric field distributions were analysed at four longitudinal cross-sections of the heart model.

The Singular Integral Equations Method (SIE) used in this article allowed us to solve Maxwell's Equations for a Three-Dimensional (3D) asymmetric heart model when a microwave catheter (MC) was placed inside the model and radiated microwaves. Here we explain the main idea of our SIE method. We first separated the solution of equations from satisfying the boundary conditions. For this purpose, we found the solution of the differential equations having a point source. This fundamental solution is used in our integral representation of a problem. The integral representation automatically satisfied the differential equations but has an unknown density function which must be found from the boundary conditions. The solution of the differential equations, obtained by our SIE method, was rigorous, that is it satisfied the differential equations and all boundary conditions. The false roots did not occur when applying our SIE method. All surfaces of the heart model were defined as a triangular mesh covering the 3D heart surfaces. The heart model consisted of cardiac muscle and the right and left atriums with ventricles which were filled with blood. In this article we presented our calculations of the microwave electric field inside of a heart model. We have seen that our SIE method enabled one to optimal the size and shape of a MC when used to remove abnormal tissue in a heart model. We discovered that the electric field distribution most suitable for microwave ablation was a curved microwave catheter pressed against the lateral surface of heart atrium.

Application models for simulation are usually built by combining and configuring a selection of component models into an application model. This can be done by manually editing the model text representations. However, it is usually much easier to use a graphic editor for selecting och connecting components. The MathModelica tool has such a graphic editor, adapted for components in Modelica libraries. However, since Modelica is a generic model description language, it has been possible to extend the editor to support configuration of components in other modeling tool formats, e.g. ADAMS or ANSYS. When the editor is used in this generic way, the Modelica connections and interfaces are translated into the format of the specific tool. The editor does not need to know anything about the internals of model components that are combined, just the interfaces. The configurator has successfully been used to configure and simulate mechanical bearing models as well as a wheel loader model, currently supporting three different formats: Modelica MBS, ADAMS, and ANSYS, with ongoing development for the SKF BEAST MBS model format

Recent years have witnessed a significant growth of interest in modeling and simulation of engineering application systems. A key factor in this growth has been the development of efficient equation-based simulation languages, with Modelica as one of the prime examples. Such languages have been designed to allow automatic generation of efficient simulation code from declarative specifications. A major objective is to facilitate reuse and exchange of models, model libraries, and simulation specifications.

The Modelica language and its associated support technologies have achieved considerable success through the development of domain libraries in a number of technical areas. By using domain-libraries complex simulation models can be built by aggregating and combining submodels and components from various physical domains.

The concept of safe engineering practices has been one of the most important guidelines when designing Modelica. This made it natural to make Modelica a statically strongly typed language, which allows the compiler to check the consistency of a design before it is executed, in contrast to dynamically typed languages such as Matlab.

The ability of static checking has also influenced the design of conditional equations and the ongoing the design of variant handling features in Modelica. Moreover, the language allows support for standardized physical units, thus enabling tools for unit checking of relationships and connections between interfaces. A third possible level of checking is through design rules within application-specific libraries, which can be enforced via assert statements. These properties taken together gives a good foundation for safe engineering practices, even though more work is needed to further increase the safety quality level.

The singular integral equations method elaborated in this paper allows us to solve accurately the Maxwell’s equations for a three-dimensional (3D) model heart exposed to electromagnetic radiation in the frequency range SHF and EHF. To test our algorithm we have computed the back scattering cross-section for a metal disc. Our computations are in good agreement with experiment given in literature. To demonstrate the usefulness of the algorithm we have computed the scattering characteristics of a simplified model of the human heart. This model is composed of the myocardium, the right and left atria and ventricles. All surfaces of the model are defined a triangular mesh in 3D covering the heart surfaces and normals to the triangles.

The open source software movement has received enormous attention in recent years. It is often characterized as a fundamentally new way to develop software. This paper describes an effort to develop an open source Modelica environment  to  a  large  extent based on a formal specification of Modelica, coordinated by PELAB, Department of Computer and Information Science, Linköping University, Sweden. The current version of the system provides an efficient interactive computational environment for most of the expression, algorithm, and function parts of the Modelica language as well as an almost complete static semantics for Modelica 2.0.

The longer-term goal is to provide reasonable simulation execution support, at least for less complex models, also for the equation part of Modelica which is the real essence of the language. People are invited to contribute to this open source project, e.g. to provide implementations of numerical algorithms as Modelica functions, add-on tools to the environment, or contributions to compiler itself. The source code of the tool components of the open source Modelica environment is available under the Gnu Public License, GPL. The library components are available under the same conditions as the standard Modelica library. The system currently runs under Microsoft Windows, Linux, and Sun Sparc Solaris. A benchmark example of running a simplex algorithm shows that the performance of the current system is close to the performance of handwritten C code for the same algorithm.