| Biology electrical impedance is a kind of physics quantum reflecting biology tissue,apparatus,cell or the electrics character of whole biology economy. The biology electric impedance technology, which is a kind of check technique without trauma, is to distill biomedicine information related to physiology or pathology of God's image according to the electricity characteristic or the change of biology tissue and apparatus. Based on the analysis and research of the domestic and overseas EIT algorithms, a practical and fast EIT algorithm with better resolution---Fast Newton's One-Step Error Reconstructor (FNOSER) dynamic algorithm is studied and realized in this dissertation. Based on a great deal of experiment researches, the EIT algorithm and performance of hardware-measuring device needed by imaging system are analyzed. The main work is described as follows: (1). The primary drive patterns such as adjacent, polar and cross drive are studied. With all elements'conductivity being considered as one, the data and curve from adjacent, polar and cross drive patterns are compared with EIT simulating software. Based on the commonness of the three drive patterns, the concept of uniform drive pattern and drive angle is put forward. Data analysis result indicated that with the same hardware, the stability of data-measuring is improved continuously when the drive angle kept on increasing. (2). FNOSER static algorithm has been brought forward based on the detail study on One-Step Error Reconstructor algorithm of the static EIT. As the Jacobi Matrix of Fast One-Step Newton Error Reconstructor algorithm can be calculated previously t, the same imaging speed as back-projection algorithm can be made. The study results show that the FNOSER algorithm can obtain static image with a character of high space resolution, accurate orientation, fast imaging, and so on. (3). The FNOSER dynamic algorithm has been put forward based on the FNOSER static algorithm, and the relationship between static and dynamic algorithm has also been studied aiming at FNOSER and back-projection. In the FNOSER and back-projection algorithm, the dynamic and static algorithm are uniform and can be transformed each other. If the reference voltage data is the ideal reference voltage obtained from "measure voltage"considering symmetrical distribution of unit resistance in finite element forward calculation, it's a static algorithm. If reference voltage data is obtained from the first value (or called former value), it's a dynamic algorithm. (4). The back-projection and FNOSER algorithm have been simulated to make a compare. Without strong mathematical theory basis, the back-projection algorithm is a kind of electrical impedance imaging algorithm using the CT back-projection theory for reference, and it has a bad imaging resolution because its projection and path are not only curve, but also very wide, called "Wide Projection"with different area sizes. FNOSER algorithm has strong mathematical theory basis. Research show that FNOSER algorithm can distinguish targets well than back-projection algorithm (5). Eliminating spurious loci algorithm is put forward. The spurious loci mainly come from noise and error included in measure data. For star false trace is indigenous to back-projection algorithm and theory, aiming at two different imaging algorithm back-projection and FNOSER, the simulation and experiments results show apart that mean algorithm has a better capability of avoiding spurious loci to make imaging target more clear. (6). EIT imaging software system has been developed. The system is an integrated whole including simulation and real-time data gathering imaging, whose finite element model can be analyzed automatically and size can be adjusted. The isoline and nephogram drawing algorithm in finite element after-management have been realized. It supports uniform drive pattern and its drive angle can be adjusted at will. (7). Many experimental researches have been carried out with the hardware and imaging software. Experiment results show that definition of imaging using FNOSER dynamic algorithm is better than that of back-projection dynamic algorithm. A lot of experiments have been done to study different objects, such as perspex bar, aluminum bar, pencil and 2mm lead, etc. Studies show that by using FNOSER dynamic algorithm in EIT system, these objects in the flume can be accurately displayed, and the resolution is very high. Relative size and position can also be reflected. Clear reconstructed images can be obtained through experimental data based on plaster cast perspex. (8). Experiments have been done on a grown rabbit. Objects have been put into thorax and skull of a rabbit, and clear dynamic re-construction images have been obtained by using FNOSER dynamic algorithm. (9). Drive angle experiments show that small objects, such as pencil, can not be imaged when there is only one electrode for drive angle in EIT device II, but when there are 3 electrodes or more than that for drive angle, these small objects can be imaged. So,increase on drive angle helps to improve imaging effect of single target. When there are 2 or 3 electrodes for drive angle, the limit between two targets is obvious and the images are very clear. In course of increasing electrodes for drive angle from 4, the re-construction image of central target becomes weaker and darker. When there are 8 electrodes for drive angle, the central image becomes so dark that two targets with the same size can not be distinguished from image. (10). FNOSER static algorithm has been studied. Collectivity of realizing on experimental device in existence is unsuccessful, which results from great system error. So there is a need for improving hardware-measuring device and imaging algorithm to make static algorithm better applied.
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