本文關(guān)鍵詞：磁共振成像系統(tǒng)中數(shù)字光纖傳輸技術(shù)研究　出處：《華東師范大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

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【摘要】：隨著核磁共振成像技術(shù)的發(fā)展,磁共振接收機(jī)的通道數(shù)越來(lái)越多,對(duì)核磁共振數(shù)據(jù)傳輸?shù)膸�、傳輸過(guò)程中數(shù)據(jù)的準(zhǔn)確性等都有了更高的要求。在常規(guī)核磁共振系統(tǒng)中,掃描室與設(shè)備室之間通常用同軸電纜對(duì)模擬的核磁共振信號(hào)進(jìn)行傳輸。同軸電纜在傳輸模擬信號(hào)的過(guò)程中存在損耗,并且多通道的射頻電纜之間還會(huì)存在耦合,同時(shí)信號(hào)還會(huì)受到電磁波的干擾,從而導(dǎo)致核磁共振圖像質(zhì)量下降。基于上述同軸電纜傳輸過(guò)程中的一些不足,本文提出了 一種核磁共振數(shù)據(jù)數(shù)字光纖傳輸方案。在數(shù)字光纖傳輸方案中,由于數(shù)字光纖傳輸具有損耗小、受外界電磁波的影響小、頻帶寬、傳輸容量大等一些優(yōu)點(diǎn),因此數(shù)字光纖傳輸方案可以很好的解決同軸電纜在傳輸核磁共振信號(hào)過(guò)程中帶來(lái)的問(wèn)題,從而提高了圖像的信噪比。在本文中通過(guò)對(duì)多種串行協(xié)議的分析,得出基于Seriallite協(xié)議的自定義數(shù)字光纖傳輸方案,在此協(xié)議中利用QUARTUS Ⅱ軟件中的Mega Wizard Plug-In Manager工具生成的LPM_MUX IP核,實(shí)現(xiàn)核磁共振數(shù)據(jù)的復(fù)用和分接功能,并通過(guò)對(duì)ALTGXIP核進(jìn)行配置實(shí)現(xiàn)時(shí)鐘生成和恢復(fù)、8B/10B編解碼、字節(jié)串化、字對(duì)齊處理、串并轉(zhuǎn)換和差分電壓控制等功能。另外還對(duì)高速收發(fā)器的重配置模塊、時(shí)鐘生成模塊和邏輯控制模塊進(jìn)行了設(shè)計(jì)和配置。為了保證核磁共振系統(tǒng)激發(fā)信號(hào)和接收到的核磁共振信號(hào)具有相位相干性,首先必須使激發(fā)單元和接收單元參考同一個(gè)時(shí)鐘源。本文利用了時(shí)鐘數(shù)據(jù)恢復(fù)(Clock Data Recovery,CDR)單元,從輸入串行的核磁共振數(shù)據(jù)流中恢復(fù)出時(shí)鐘,保證了核磁共振數(shù)據(jù)發(fā)送端和接收端的參考時(shí)鐘具有相位相干性,最終實(shí)現(xiàn)了數(shù)字光纖傳輸方案。在本方案中,通過(guò) PCIE(Peripheral Component Interconnect Express)總線實(shí)現(xiàn)對(duì)核磁共振數(shù)據(jù)的讀和寫(xiě),并利用示波器和SignalTapⅡ邏輯分析儀對(duì)核磁共振數(shù)據(jù)進(jìn)行了測(cè)試,并驗(yàn)證了數(shù)字光纖傳輸方案的時(shí)鐘相干性和收/發(fā)數(shù)據(jù)的一致性。最終通過(guò)圖像重建得到了人腦核磁共振圖像,同時(shí)也驗(yàn)證了數(shù)字光纖傳輸方案的可行性。本文基于Seriallite協(xié)議,對(duì)核磁共振接收通道數(shù)據(jù)的傳輸格式進(jìn)行了定義,傳輸實(shí)時(shí)性較高。利用時(shí)鐘恢復(fù)單元不僅確保了時(shí)鐘的相干性,且不需要專門(mén)的時(shí)鐘傳輸通道,從而簡(jiǎn)化了電路結(jié)構(gòu)。另外數(shù)字光纖傳輸方案的研究還為后續(xù)的數(shù)字光纖多模塊級(jí)聯(lián)傳輸?shù)於嘶A(chǔ),使得更多通道的磁共振數(shù)據(jù)在單根光纖上進(jìn)行串行傳輸成為可能。
[Abstract]:With the development of nuclear magnetic resonance imaging technology, the number of channels in magnetic resonance receiver becomes more and more, and the bandwidth of nuclear magnetic resonance data transmission. The accuracy of the data in the transmission process has higher requirements. In the conventional nuclear magnetic resonance system. The simulated nuclear magnetic resonance (NMR) signal is usually transmitted by coaxial cable between the scanning room and the equipment room. There is loss in the transmission of analog signal and coupling between multi-channel RF cables. At the same time, the signal will also be interfered by electromagnetic wave, resulting in the quality of nuclear magnetic resonance image decline. Based on the above coaxial cable transmission process of some shortcomings. In this paper, a digital optical fiber transmission scheme for nuclear magnetic resonance data is proposed. In the digital optical fiber transmission scheme, due to the low loss of digital optical fiber transmission, the influence of external electromagnetic waves is small, and the frequency bandwidth is small. Some advantages such as large transmission capacity, so the digital optical fiber transmission scheme can solve the problem of coaxial cable in the process of nuclear magnetic resonance signal transmission. In this paper, through the analysis of various serial protocols, the self-defined digital optical fiber transmission scheme based on Seriallite protocol is obtained. In this protocol, the LPM_MUX IP core is generated by using the Mega Wizard Plug-In Manager tool in QUARTUS 鈪，

本文編號(hào)：1383096