Today, a variety of Tomography Modalities exists based on different physical aspects

Each serves a purpose while having drawbacks

**Hybrid Tomography Modalities**

- Today, a variety of Tomography Modalities exists based on different physical aspects
- Each serves a purpose while having drawbacks:
- MRI – long acquisition time, expensive
- CT – safety issues due to radiation
- US – low contrast
- EIT – low resolution, not stable

- Hybrid Modalities offer to combine the advantages of existing modalities while reducing drawbacks

**The MAET modality**

**The Forward and Inverse problems**

- We can separate the MAET tomography into two problems
- The Forward problem:

A model of the expected measurements, given the tissue’s impedance

- The Inverse problem:

The tissue’s impedance reconstruction, given the measurements

**Project Goals**

- We restrict ourselves to the
only**Forward problem** - Our goals are:

- Understand the MAET forward problem theory model
- Develop numeric tools specified to solve the forward problem
- Build a working model simulation of the MAET measurement
- Give predictions for future experiments

- The project will help in providing a database for the
**Inverse**solution validation**problem** - Moreover, the project will provide a starting point for future experiments settings

**Projects Highlights**

- Literature review of MAET Physical and mathematical model
- Implementation of the mathematical model in Matlab
- Implementation in Comsol
- Three tissue models
- Matlab-Comsol interface
- MAET measurement simulation
- Parametric sweep study

**Simulations Results-Circular**

**Simulations Results-Elliptic**

**Simulations Results-Multi**

**Simulation Conclusions**

- The conductivity map is the main factor which determines the measurement profile
- Different model width leads to measurement scaling
- Variation in Electrodes size has negligible effect
- Variation in Electrodes position results in different measurement profile
- Dispersion has minor effect on measurement profile
- Expected voltage scale is in milliVolt to microVolt ,time in microseconds

**Summary**

- Hybrid tomography modalities
- MAET forward problem formulation and theory
- Implementation of Poisson solver in Matlab in different coordinate systems
- Maet simulation in Matlab
- Comsol usage and integration with Matlab
- Various tissue models simulation and comparisons
- Experiment oriented conclusion

**Further Study**

- Detailed ultrasound model
- Theory validation in a real world experiment
- MAET inverse problem simulation

**Forward Problem Theory**

- Starting assumptions:
- Quasi-staticRegime
- Ultrasound wave can be focused on to a very small volume
- Controllable constant magnetic field
- Tissue electro-neutrality
- No outgoing current in tissue boundary beside probes

** References**

- S. Haider, a Hrbek, and Y. Xu, “Magneto-acousto-electrical tomography: a potential method for imaging current density and electrical impedance.,”
*Physiol. Meas.*, vol. 29, no. 6, pp. S41–S50, 2008. - H. A. Haus and J. R. Melcher, “Electromagnetic Fields and Energy,”
*Massachusetts Institute of Technology*. [Online]. Available: http://web.mit.edu/6.013_book/www/chapter7/7.2.html. [Accessed: 07-Sep-2015]. - L. N. Dworsky,
*Introduction to Numerical Electrostatics Using MATLAB*, 1st Edition. Wiley-IEEE Press, 2014.