Research Of Electrical Impedance Tomography Algorithm For Gastric Motility

The detection and evaluation of gastric motility is very valuable for judging functional stomach intestine disease. It has general clinic requirements. Considering the high incidence of functional digest disease and the limitation of existent equipment, electrical impedance tomography may afford a new way to evaluate gastric motility. Electrical impedance tomography has a great superiority of judging in functionality and morphology. At the same time, it is simple, non-invasive, low-cost, which make it possible for patients to have a long-term, continuous monitoring. This paper focuses on implementing an effective back- projection algorithm, which is suit for stomach region by studying the forward and inverse problems of electrical impedance tomography.This paper mainly completes the following work:(1)To give out an idea that referenced to human anatomy stomach data fusion, implemented the finite element mesh model of stomach that based on the true boundaries of the body contour.(2)To study the forward problem of the EIT. Complete the mathematical description and the forward calculation of the EIT. Set uniform conductivity, generate electrical conductivity matrix, impose boundary conditions, load current, take use of LU decomposition to solve the matrix equation, and seek potential of all nodes. Analysis the boundary potential and relative potential change rate of following cases, conductivity value change, conductivity position change and conductivity area change, and so on.(3)To study the inverse problem of the EIT. Introduce the basic principles and mathematical description of the back-projection, imaging algorithm is completed. Set non-uniform conductivity of different scenarios to calculate the boundaries of all cases, the distribution of potential. Obtain two adjacent electrodes potential pressure under the same electrode stimulates situation. Compare this pressure with the uniform distribution of the pressure, and then normalize potential pressure and electrical conductivity.(4)List reconstructed images in a variety of electrical conductivity change cases. Analysis imaging results, evaluate gastric motility. Studies show that, back- projection imaging algorithm can reflect targets on the field and reaction of gastric emptying in a certain resolution way. When the conductivity distribution changes, the reconstructed image will change. All this can reflect the reaction of gastric peristalsis. Back projection algorithm can locate the target area on the field, the situation of gastric emptying. It has a certain resolution. When the distribute conductivity changes, the reconstructed image can reflect changes of conductivity, and the reaction of gastric motility situation. At last, this topic makes further prospects, hopes to improve the imaging algorithm to improve image resolution, to eliminate artifacts.