本文選題：電阻抗成像 + 直接數(shù)字頻率合成　； 參考：《天津工業(yè)大學(xué)》2017年碩士論文

【摘要】：電阻抗成像技術(shù)是醫(yī)學(xué)成像技術(shù)新的發(fā)展方向,其受到了相關(guān)領(lǐng)域研究者的廣泛關(guān)注。與現(xiàn)有醫(yī)學(xué)成像技術(shù)相比,有著當(dāng)前已臨床應(yīng)用的成像技術(shù)不具有的獨(dú)特優(yōu)點(diǎn),它具有無創(chuàng)、無害、不使用核素和可連續(xù)性監(jiān)測的特點(diǎn),尤其是更具有功能成像的特點(diǎn),這對疾病的診斷和預(yù)防有著重要意義。當(dāng)前已有EIT硬件系統(tǒng)電路均需要雙電源供電,且系統(tǒng)電路復(fù)雜,模擬器件繁多。為了簡化EIT硬件系統(tǒng)電路、減小測量設(shè)備體積以及提高硬件系統(tǒng)的移動性,本文建立了一套完整的EIH硬件系統(tǒng),并對建立后的硬件系統(tǒng)進(jìn)行了實(shí)際的實(shí)驗(yàn)測量。本文基于單片機(jī)和FPGA作為主控電路建立了一套EIH硬件系統(tǒng)。首先確立了一可行易于實(shí)現(xiàn)的EIT硬件系統(tǒng)設(shè)計方案,其主要包括主控器件的選擇、正弦信號激勵源的設(shè)計及實(shí)現(xiàn)、多路模擬開關(guān)與電極系統(tǒng)的選擇與設(shè)計、激勵模式的實(shí)現(xiàn)以及對被測信號的解調(diào)技術(shù)實(shí)現(xiàn)。根據(jù)目前已有的頻率合成技術(shù),設(shè)計并實(shí)現(xiàn)了基于直接數(shù)字頻率合成技術(shù)的信號發(fā)生器,能夠?qū)崿F(xiàn)頻率、幅值可調(diào);簡要分析了目前應(yīng)用于EIT硬件系統(tǒng)中的常見的電壓控制電流源,并根據(jù)電流源的特性,對電流源電路進(jìn)行了優(yōu)化;根據(jù)本系統(tǒng)的設(shè)計特點(diǎn),選取了正交序列解調(diào)的方法實(shí)現(xiàn)對被測信號的的相敏解調(diào);制作了 16電極鹽水槽作為實(shí)驗(yàn)測量對象,并選取相鄰激勵模式實(shí)現(xiàn)對被測對象的測量。在EIT硬件系統(tǒng)各個電路部分搭建好之后,分別進(jìn)行了調(diào)試和實(shí)驗(yàn)。得到了正弦信號發(fā)生器的波形測試結(jié)果,對優(yōu)化后的電流源電路各項(xiàng)參數(shù)進(jìn)行了測量和計算,對建立的實(shí)驗(yàn)鹽水槽模型進(jìn)行測量得到了關(guān)于通道一致性的曲線。實(shí)驗(yàn)結(jié)果證明,正弦信號發(fā)生器可輸出較穩(wěn)定的信號,電流源具有較好的性能,系統(tǒng)具有一定的通道一致性。本系統(tǒng)能夠?qū)崿F(xiàn)對基于鹽水槽模型為對象進(jìn)行激勵和測量,并獲得較穩(wěn)定的測量結(jié)果。本文這一實(shí)現(xiàn)方法為便攜式的EIH硬件系統(tǒng)設(shè)計提供了參考。
[Abstract]:Electrical impedance imaging technology is a new development direction of medical imaging technology, which has been widely concerned by researchers in related fields. Compared with existing medical imaging technologies, it has unique advantages that are not available in current clinical applications. It has the characteristics of non-invasive, harmless, non-nuclide use and continuous monitoring, especially functional imaging. This is of great significance to the diagnosis and prevention of diseases. At present, EIT hardware system circuits all need dual power supply, and the system circuit is complex and analog devices are various. In order to simplify the circuit of EIT hardware system, reduce the volume of measuring equipment and improve the mobility of hardware system, a complete EIH hardware system is established in this paper. In this paper, an EIH hardware system is established based on MCU and FPGA as the main control circuit. First, a feasible and easy to implement EIT hardware system design scheme is established, which mainly includes the selection of main control device, the design and implementation of sinusoidal signal excitation source, the selection and design of multi-channel analog switch and electrode system. The actualization of the excitation mode and the demodulation technology of the measured signal. According to the existing frequency synthesis technology, a signal generator based on direct digital frequency synthesis technology is designed and implemented, which can realize frequency and amplitude adjustable. This paper briefly analyzes the common voltage-controlled current source used in EIT hardware system, and optimizes the current source circuit according to the characteristics of the current source, according to the design characteristics of the system, The method of quadrature sequence demodulation is selected to realize the phase sensitive demodulation of the measured signal, and the 16 electrode salt tank is made as the experimental object, and the adjacent excitation mode is selected to realize the measurement of the tested object. After each circuit of EIT hardware system is built up, debugging and experiment are carried out respectively. The waveform test results of the sinusoidal signal generator are obtained. The parameters of the optimized current source circuit are measured and calculated. The curves of channel consistency are obtained by measuring the established salt tank model. The experimental results show that the sinusoidal signal generator can output stable signals, the current source has better performance, and the system has a certain channel consistency. The system can realize the excitation and measurement based on salt flume model, and obtain more stable measurement results. This method provides a reference for the design of portable EIH hardware system.
【學(xué)位授予單位】：天津工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：R310;TP391.41

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 萇飛霸;張和華;顏樂先;尹軍;;電阻抗斷層成像技術(shù)研究[J];中國醫(yī)療器械雜志;2016年01期

2 鄧娟;王磊;李福生;趙舒;王妍;沙洪;;實(shí)用化EIT條件下不同激勵模式成像效果仿真研究[J];中國生物醫(yī)學(xué)工程學(xué)報;2015年04期

3 林興建;趙偉杰;劉曉娟;厲力華;;用于生物電阻抗檢測的Howland電流源恒流特性研究[J];生物醫(yī)學(xué)工程學(xué)雜志;2015年02期

4 李蔚琛;史學(xué)濤;夏軍營;尤富生;楊琳;張戈;付峰;董秀珍;;用于生物電阻抗成像系統(tǒng)的鏡像反饋電流源的研究[J];醫(yī)療衛(wèi)生裝備;2015年02期

5 徐燦華;董秀珍;;生物電阻抗斷層成像技術(shù)及其臨床研究進(jìn)展[J];高電壓技術(shù);2014年12期

6 侯海嶺;王化祥;陳曉燕;;應(yīng)用于肺部EIT系統(tǒng)的激勵電流源設(shè)計[J];自動化儀表;2014年01期

7 張偉興;馬藝馨;;EIT激勵電流切換用模擬多路開關(guān)的選擇[J];儀表技術(shù)與傳感器;2013年10期

8 冉鵬;何為;徐征;李冰;鞠康;;基于數(shù)字處理的頻差電阻抗成像系統(tǒng)設(shè)計[J];儀器儀表學(xué)報;2013年02期

9 李剛;周梅;何峰;林凌;;基于數(shù)字鎖相相關(guān)計算結(jié)構(gòu)的優(yōu)化算法[J];電子與信息學(xué)報;2012年03期

10 李剛;郝麗玲;邢佳;林凌;;用于生物阻抗測量的同步多通道高精度恒流源[J];電子產(chǎn)品世界;2012年03期

相關(guān)博士學(xué)位論文 前2條

1 范文茹;生物電阻抗成像技術(shù)研究[D];天津大學(xué);2010年

2 王妍;電阻抗斷層成像電極系統(tǒng)性能與評價方法研究[D];中國協(xié)和醫(yī)科大學(xué);2009年

，

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