2DYNAEIT

de Dynaflow

In Electrical Impedance Tomography (EIT) the distribution of conductivity inside a container is sought by applying specified currents (or voltages) at some parts of the container surface, and performing measurements of the voltage (or current) at some other parts. The equations for the electric field then provide relationships between the conductivity distribution inside the domain and the measured voltages and currents. Different types of materials have different conductivity, and the availability of a conductivity map provides an image of the material distribution in the container.

Principle:

2DynaEIT is a suite of efficient and accurate algorithms for solution of the inverse and forward EIT problems. These were developed under Phase I and Phase II SBIR contracts with the National Science Foundation. The inverse problem is the problem of image reconstruction using the measured voltages and/or currents, while the forward problem is the problem of determination of voltage and current distribution for known conductivity distribution in the imaged domain.

We have developed CPU-efficient methods, such as the Dipole Approximation (DA), and  the Singular Boundary Element Method (Singular BEM). These allow one to solve rapidly the forward EIT problem in 2 and 3 dimensions. This enables application of multi-dimensional minimization procedures, such as Powell's Direction Set Method, Downhill Simplex Method, Conjugate Gradient Method, and Genetic Algorithms, for solution of the inverse problem, which requires thousands of calls of the forward problem solver. We also applied multi-objective minimization based on Pareto sets.

Applications:

The two and three-dimensional EIT algorithms that we have developed can be applied for medical imaging, multiphase flows imaging encountered in chemical, oil and gas, energy, and aerospace industries, non-destructive evaluation of structures and materials, imaging of underground water paths and container leakage, archaeology, detection of buried objects, chemical reactive flows, and many others.

Application areas of EIT software are not limited by imaging based on electrical properties. Since our methods of solution are based on the solution of the classical Laplace, Poisson, and Helmholtz equations which describe a wide variety of physical phenomena, including filtration, acoustical, optical, thermal, and other processes, the developed software can be adjusted for such problems as evaluation of oil and gas deposits, based on log data, seismic imaging, and imaging of temperature and pressure fields in various industries. We also can work on solution of similar user defined forward and inverse problems of multidimensional imaging.