旋轉式電阻抗斷層攝影系統性能改善與應用

電阻抗斷層攝影術(Electrical impedance tomography, EIT)為新一代的醫學成像技術，具有低成本、可攜與可長期連續監控的優點。本論文將以高精確度、高分辨率的阻抗成像及加快成像速度為主要目標，針對原有的旋轉式電阻抗斷層攝影術(Rotary Electrical impedance tomography, REIT)系統性能做進一步的改善，並實現一個應用快速牛頓單步誤差重建(Fast Newton’s One-Step Error Reconstructor,FNOSER)動態演算法之旋轉式電阻抗成像系統。本文主要工作如下: (1)設計一新型複合式電極結構，改善系統易受雜訊干擾與銅電極氧化的影響，增加原始訊號可靠度，提高系統量測的精確度。 (2)分析相鄰、交叉、相對三種資料擷取法之性能，進一步提出修正式相鄰法，可改善成像分辨率，提高影像品質。 (3)應用快速牛頓單步誤差重建演算法，作為REIT系統的重建演算法。改善旋轉式電極系統在計算Jacobian 矩陣和反矩陣相當耗時的問題，加快成像速度。 (4)針對工業處理槽的程序監控應用上，由REIT系統模擬導電邊界之環境，進行鹽水槽阻抗成像實驗。

關鍵字

旋轉式電阻抗成像系統；導電邊界；資料擷取方式；快速牛頓單步誤差重建動態演算

並列摘要

Electrical Impedance Tomography (EIT) is a new technique that produces images by computing electrical properties within the human body. The advantages of EIT include: (1) inexpensive and compact equipment; (2) safety for examining. The objective of this paper is to improve the performance (precision, distinguishability and computation time) of the original Rotary Electrical Impedance Tomography (REIT) system. The Fast Newton’s One-Step Error Reconstructor (FNOSER) is applied in this study to reconstruct the impedance image. The main results of this paper are described as follows: (1) Because the accuracy of the measurement data is easily influenced by the noise and the oxidization of the metal electrode, we design a new configuration of the compound electrode to improve the signal-to-noise ratio and the distinguishability. (2) By analyzing the performance of the adjacent, cross and opposite current pattern, we propose a modified adjacent configuration to improve the quality of the images. (3) Because increasing the number of boundary voltage would raise the computation time, we apply the Fast Newton’s One-Step Error Reconstructor to improve the efficiency of computation. (4) For the application and monitor of the REIT system on industrial process, the experiment of conducting wall tank is carried out in the REIT system.

並列關鍵字

Rotary Electrical Impedance Tomography (REIT) ； FNOSER ； data collection methods ； conducting wall

參考文獻

[1] J. G. Webster, "Electrical Impedance Tomography," Galliard Press, pp. 1-20 , 1990.

[2] David Holder, "EDITORIAL Biomedical applications of electrical impedance tomography," 2001 Physiological Measurement.22

[4] A. M. Dijkstra, B.H. Brown, A. D. Leathard, "Clinical Applications Of Electrical Impedance Tomography," Medical Engineering and Technology,1993, 17(3):89-98.

[5] Y. Kim, H. W. Woo, A. E. Luedtke , "Impedance Tomography and its Application in Deep Venous Thombosis Dectction, "IEEE Engineering in Medicine and Biology Magazine, 1989, March:46-49.

[6] B. H. Brown, D.C. Barber, A. H. Morice and A. D. Leathard "Cardiac and Respiratory Related Electrical Impedance Changes in the Human Thorax," IEEE Trans. Biomed.Eng.41:729-734

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旋轉式電阻抗斷層攝影系統性能改善與應用

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