發(fā)布時間：2018-06-02 22:31

  本文選題：光學相干層析成像 + 成像深度　； 參考：《上海交通大學》2015年博士論文

【摘要】：精準、快速、有效的眼組織成像和參數(shù)測量對眼科基礎研究和臨床診療具有十分重要的應用價值。在臨床眼科成像技術中,光學相干層析成像技術(Optical Coherence Tomography,OCT)以其無接觸、非侵入、高分辨率、高速、實時等優(yōu)點,在眼科疾病檢測和臨床研究中呈現(xiàn)出巨大的潛力。但是,由于成像深度的限制,常用OCT系統(tǒng)無法實現(xiàn)對全眼前節(jié)乃至全眼結構的同時成像,限制了其在眼科領域的應用范圍。因此,本文的研究目的在于拓展譜域OCT(Spectral-domain OCT,SD-OCT)系統(tǒng)的探測深度,使之能夠準確完整地反映全眼組織層析結構特征,以提供更加豐富有價值的全眼參數(shù)信息用于眼科基礎研究和臨床檢查。針對以上研究目的,本研究利用雙通道雙焦點技術與消共軛技術相結合的方法,研制并優(yōu)化大成像范圍的SD-OCT系統(tǒng),實現(xiàn)了高分辨率全眼組織同時成像,并利用以上技術對調節(jié)所引起的眼內組織形態(tài)變化進行了全面深入的研究。本論文的主要研究內容和結果如下:首先,研制雙通道雙焦點SD-OCT系統(tǒng),成功實現(xiàn)了對人眼全眼前節(jié)組織的同時成像及參數(shù)測量并保證了較高的橫向分辨率。將該系統(tǒng)用于觀察放松和不同調節(jié)狀態(tài)下的眼前節(jié)參數(shù)變化,實驗結果支持了經典眼調節(jié)理論,同時也證實了雙通道雙焦點SD-OCT系統(tǒng)用于眼前節(jié)參數(shù)測量和眼調節(jié)功能研究中的可行性。其次,為了進一步提高系統(tǒng)的成像深度,在原有雙通道雙焦點sd-oct系統(tǒng)的基礎上,結合消共軛技術,成功實現(xiàn)了全眼前節(jié)和視網(wǎng)膜的同時成像,并基于合成的全眼圖像測得了相應的眼參數(shù)。實驗結果證明該系統(tǒng)對人眼軸向參數(shù)的測量具有很好的重復性。另外,將該系統(tǒng)與臨床常用的iolmaster生物測量儀進行對比,發(fā)現(xiàn)兩者對前房深度和眼軸長的測量結果具有高度的相關性和一致性。因此,消共軛型雙通道雙焦點sd-oct系統(tǒng)可作為一種準確可靠的生物成像測量技術為臨床眼科診斷和研究提供更詳細豐富的圖像信息。再次,由于調節(jié)引起的視網(wǎng)膜牽拉或變形可能與視覺感知變化有關,高分辨率的影像測量學技術可為研究調節(jié)引起的視網(wǎng)膜厚度變化以及牽拉現(xiàn)象提供一種更直接準確的定量分析。本研究利用改進的雙通道雙焦點sd-oct系統(tǒng)對人眼最大調節(jié)前后的角膜和視網(wǎng)膜同時進行三維成像,并計算了視網(wǎng)膜厚度、視網(wǎng)膜體積和眼軸長。實驗結果表明,在最大調節(jié)狀態(tài)下,中央凹周圍4-mm2黃斑區(qū)域的視網(wǎng)膜顯著變薄,且該變化與象限無關。這是首次利用視網(wǎng)膜厚度變化的影像測量學證據(jù)證明了人眼調節(jié)時視網(wǎng)膜可能存在的牽拉或變形現(xiàn)象。最后,為進一步解決視網(wǎng)膜成像范圍和系統(tǒng)成像信噪比受限等問題,研制了一套中心波長在1050nm和840nm的雙波段雙焦點sd-oct系統(tǒng),實現(xiàn)了大范圍、高探測靈敏度的全眼組織同時成像。利用雙波段探測光束和樣品臂的特殊光學設計,不但解決了原系統(tǒng)信號衰減的問題,而且實現(xiàn)了雙掃描雙焦點結構,從而最優(yōu)化兩個成像通道(特別是對視網(wǎng)膜成像)的橫向分辨率、焦深和掃描范圍。將該系統(tǒng)用于觀察和測量+6d調節(jié)前后的全眼參數(shù)變化,實驗結果與經典眼調節(jié)假說基本一致,同時該研究還發(fā)現(xiàn)了調節(jié)時眼軸長顯著增加。調節(jié)引起的眼軸伸長可能與近距離工作引起的暫時性近視的發(fā)生相關。因此,該成像系統(tǒng)不僅能用于眼科疾病的檢測,同時還能為眼調節(jié)、屈光不正等眼視光學研究提供強有力的技術支持。本論文重點解決了SD-OCT系統(tǒng)成像深度拓展和同時大范圍成像的技術難題,實現(xiàn)了全眼組織的高分辨率同時成像和眼參數(shù)的高精度測量。同時,利用所研制的系統(tǒng),精確測量了眼調節(jié)引起的全眼組織形態(tài)變化,從中發(fā)現(xiàn)了調節(jié)引起的眼軸長增加和視網(wǎng)膜牽拉的直接證據(jù)。本論文的研究成果不僅為眼科疾病的檢查診斷和基礎研究提供了一種強大的成像測量工具,也為眼調節(jié)功能的深入研究提供了有利的理論依據(jù)和實驗參考。
[Abstract]:Accurate, rapid and effective eye tissue imaging and parameter measurement are of great value for the basic ophthalmology and clinical diagnosis and treatment. In the clinical ophthalmic imaging technology, Optical Coherence Tomography (OCT) has the advantages of non contact, non invasion, high resolution, high speed, real-time and so on, in the ophthalmological examination. However, because of the limitation of imaging depth, the common OCT system can not achieve simultaneous imaging of the whole eye and the whole eye structure, which limits its application in the field of Ophthalmology. Therefore, the purpose of this study is to expand the depth of the detection depth of the spectral domain OCT (Spectral-domain OCT, SD-OCT) system. It can accurately and completely reflect the structural characteristics of the whole eye tissue, so as to provide more valuable information of all eye parameters for basic ophthalmology and clinical examination. For the purpose of the above research, this study develops and optimizes the SD-OCT system of large imaging range by the combination of dual channel dual focus technology and elimination of conjugation. The main research contents and results of this paper are as follows: first, a dual channel dual focus SD-OCT system is developed, which successfully realizes simultaneous imaging of the eyes of the eye. The parameters are measured and the high lateral resolution is guaranteed. The system is used to observe the changes in the parameters of the anterior segment under the condition of relaxation and adjustment. The experimental results support the classical eye adjustment theory. At the same time, it also proves the feasibility of the dual channel dual focus SD-OCT system in the study of the parameters measurement and eye regulation. Secondly, In order to further improve the imaging depth of the system, on the basis of the original dual channel dual focus SD-OCT system, combined with the elimination of conjugation technique, the simultaneous imaging of the whole eyes and the retina is successfully realized, and the corresponding eye parameters are measured on the basis of the synthetic full eye image. The experimental results show that the system has a good weight for the measurement of the axial parameters of the human eye. In addition, comparing the system with the commonly used clinical IOLMaster biometric instrument, it is found that both of them have high correlation and consistency for the measurement of anterior chamber depth and axial length. Therefore, the conjugate dual channel dual focus SD-OCT system can be used as an accurate and reliable bioimaging technique for clinical ophthalmology diagnosis and The study provides more detailed image information. Again, the retina traction or deformation caused by adjustment may be associated with visual perception changes. High resolution imaging techniques provide a more direct and accurate quantitative analysis for the study of changes in retinal thickness and traction caused by adjustment. The double channel dual focus SD-OCT system performs three dimensional imaging of the cornea and the retina before and after the maximum adjustment of the human eye, and calculates the retinal thickness, retina volume and eye axis. The experimental results show that the retina in the 4-mm2 macular region around the central concave is thinner and the change is not related to the quadrant in the maximum regulation state. In order to further solve the problems of retina imaging range and the limitation of the signal to noise ratio of the system, a set of dual focus SD-OCT system with central wavelength of 1050nm and 840nm is developed. Large range, high detection sensitivity full eye imaging. Using the special optical design of dual band detection beam and sample arm, it not only solves the problem of the signal attenuation of the original system, but also realizes the double scanning dual focus structure, thus optimizing the transverse resolution, focal depth and scanning of the two imaging channels, especially to the retina imaging. The range. The system is used to observe and measure the changes of all eye parameters before and after the +6d regulation. The experimental results are basically consistent with the classical eye regulation hypothesis. Meanwhile, the study also found that the axial length of the eye is significantly increased during the adjustment. The axis elongation caused by the adjustment may be related to the occurrence of temporary myopia caused by the close distance work. Therefore, the imaging system It can not only be used for the detection of ophthalmological diseases, but also provide strong technical support for eye optic research, such as eye adjustment and refractive error. This paper focuses on the technical problems of the depth expansion of the SD-OCT imaging system and the large range imaging at the same time. The high resolution simultaneous imaging of the whole eye and the high precision measurement of the eye parameters are realized. At the same time, the whole eye tissue morphologic changes caused by eye regulation were measured accurately by using the developed system. The direct evidence for the increase of axial length and retina traction caused by adjustment was found. The results of this paper not only provide a powerful imaging tool for the examination and diagnosis of ophthalmological diseases, but also for the eye. The in-depth study of joint function provides favorable theoretical basis and experimental reference.
【學位授予單位】：上海交通大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：R770.4

【參考文獻】

相關期刊論文 前1條

1 宋凡;趙希宇;杜睿琪;韋佳辰;許向紅;;人眼晶狀體調節(jié)機制和力學[J];力學與實踐;2012年01期

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本文編號：1970432