【摘要】：光學(xué)拓?fù)涑上穹椒ㄔ醋杂诮t外組織光譜測(cè)量技術(shù)(Near-Infrared Spectroscopy,NIRS),可實(shí)現(xiàn)高階腦功能動(dòng)態(tài)成像。作為現(xiàn)有高階腦功能成像模態(tài)如功能核磁共振成像(Functional Magnetic Resonance Imaging, fMRI)等的有效補(bǔ)充,它對(duì)腦科學(xué)研究、神經(jīng)系統(tǒng)診斷和臨床康復(fù)治療有著重要的應(yīng)用價(jià)值。目前已經(jīng)推出的光學(xué)拓?fù)涑上裣到y(tǒng)價(jià)格昂貴,較難推廣,因此設(shè)計(jì)出一種結(jié)構(gòu)簡(jiǎn)便、性?xún)r(jià)比高的光學(xué)拓?fù)涑上裣到y(tǒng)一直是目前該領(lǐng)域研究者努力的方向之一。 本文設(shè)計(jì)了一種基于數(shù)字鎖相檢測(cè)技術(shù)的光學(xué)拓?fù)涑上裣到y(tǒng),該系統(tǒng)利用數(shù)字鎖相檢測(cè)技術(shù)縮短信道帶寬、改善測(cè)量信噪比和動(dòng)態(tài)性能、實(shí)現(xiàn)微弱雙波長(zhǎng)反射信息的有效分離并提取出每個(gè)波長(zhǎng)下調(diào)制信號(hào)的幅值信息。此外,本文優(yōu)化了調(diào)制信號(hào)源以及數(shù)據(jù)采集程序,并設(shè)計(jì)出符合要求的源-探測(cè)光纖排布以及數(shù)據(jù)處理程序。在此基礎(chǔ)上,系統(tǒng)利用光開(kāi)關(guān)實(shí)現(xiàn)了5個(gè)源位置處耦合信號(hào)順序入射、并實(shí)現(xiàn)了4通道同步數(shù)據(jù)采集及處理。本文詳細(xì)介紹了系統(tǒng)的各個(gè)組成部分,并利用輸入調(diào)制信號(hào)的幅值變化與輸出反射信號(hào)的幅值變化成正比的關(guān)系,證明了系統(tǒng)的可用性以及系統(tǒng)所測(cè)得的幅值信息的有效性。 本文設(shè)計(jì)的光學(xué)拓?fù)涑上裣到y(tǒng)旨在以血紅蛋白的濃度變化為指標(biāo),實(shí)現(xiàn)腦功能成像研究。考慮到系統(tǒng)處在驗(yàn)證階段,選擇以吸收系數(shù)的變化反映血紅蛋白濃度的變化情況,在此基礎(chǔ)上對(duì)40×40mm~2區(qū)域內(nèi)不同吸收目標(biāo)的液態(tài)仿體進(jìn)行了雙波長(zhǎng)成像實(shí)驗(yàn)。以修正的Lambert-Beer定理為理論模型,重建出吸收系數(shù)的變化圖像。該成像結(jié)果準(zhǔn)確反映出吸收系數(shù)的變化趨勢(shì),初步驗(yàn)證了系統(tǒng)和方法的可行性和有效性。
[Abstract]:Optical topological imaging is derived from near infrared tissue spectroscopy (Near-Infrared Spectroscopy,NIRS), which can realize high order dynamic imaging of brain function. As an effective supplement to the existing high-order brain functional imaging modes such as (Functional Magnetic Resonance Imaging, fMRI), it has important application value in the research of brain science, the diagnosis of nervous system and the clinical rehabilitation therapy. The optical topological imaging system which has been developed is expensive and difficult to popularize, so it is one of the directions that the researchers in this field have been working hard to design a simple and cost-effective optical topological imaging system. In this paper, an optical topological imaging system based on digital phase-locked detection technology is designed. The digital phase-locked detection technique is used to shorten the channel bandwidth and improve the measurement of SNR and dynamic performance. The weak double wavelength reflection information can be separated effectively and the amplitude information of the modulation signal at each wavelength can be extracted. In addition, the modulation signal source and data acquisition program are optimized, and the source-detection fiber layout and data processing program are designed. On this basis, the system uses the optical switch to realize the sequential incidence of the coupled signals at five source positions, and realizes the synchronous data acquisition and processing of the four channels. In this paper, the components of the system are introduced in detail, and the relationship between the amplitude variation of the input modulation signal and the amplitude change of the output reflection signal is used to prove the availability of the system and the validity of the amplitude information measured by the system. The optical topological imaging system designed in this paper aims to realize the study of brain function imaging based on the change of hemoglobin concentration. Considering that the system is in the verification stage, the change of absorption coefficient is selected to reflect the change of hemoglobin concentration, and the dual-wavelength imaging experiments are carried out for different absorption targets in the region of 40 脳 40mm~2. The modified Lambert-Beer theorem is used as the theoretical model to reconstruct the changing image of absorption coefficient. The imaging results accurately reflect the changing trend of absorption coefficient, and the feasibility and effectiveness of the system and method are preliminarily verified.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類(lèi)號(hào)】：R318.51

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 蘇暢，丁海曙，白凈;生物組織光譜學(xué)技術(shù)[J];國(guó)外醫(yī)學(xué).生物醫(yī)學(xué)工程分冊(cè);1995年06期

2 王子孟;;PIN硅光電二極管的原理和應(yīng)用[J];光學(xué)儀器;1984年04期

相關(guān)碩士學(xué)位論文 前2條

1 焦玉婷;動(dòng)態(tài)擴(kuò)散光層析成像中多波長(zhǎng)數(shù)字鎖相光電檢測(cè)技術(shù)研究[D];天津大學(xué);2010年

2 馮朝軍;直接數(shù)字頻率合成（DDS）的軟件及硬件實(shí)現(xiàn)[D];西南交通大學(xué);2007年

，

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