本文關(guān)鍵詞： 角膜地形圖 角膜復(fù)原 Placido盤 屈光度 特征點(diǎn)提取　出處：《南京航空航天大學(xué)》2010年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著角膜外科手術(shù)的發(fā)展,角膜地形圖系統(tǒng)已經(jīng)成為眼科診療中必不可少的設(shè)備。Placido圓盤檢查角膜地形是應(yīng)用最為廣泛的檢查手段,它具有精度高、成本低等特點(diǎn),并且結(jié)構(gòu)簡(jiǎn)單,對(duì)噪聲敏感度低,相比其他檢查方法更適合于臨床應(yīng)用。本文致力于Placido盤檢查方法的復(fù)原算法研究與應(yīng)用,在傳統(tǒng)方法的基礎(chǔ)上,提出一種基于精確角膜頂點(diǎn)定位的復(fù)原算法,并在本文算法的基礎(chǔ)上開發(fā)角膜地形圖軟件系統(tǒng)。論文主要的研究工作如下: 1.研究了角膜的結(jié)構(gòu)和生理特性,介紹了角膜地形圖的歷史和發(fā)展現(xiàn)狀。 2.對(duì)角膜地形圖系統(tǒng)的關(guān)鍵技術(shù)展開研究,介紹了其系統(tǒng)原理以及硬件構(gòu)成。闡述了角膜地形圖圖像采集過程中的自動(dòng)對(duì)中和自動(dòng)對(duì)焦的方法;研究了圖像分析處理的方法,包括圖像預(yù)處理,中心定位以及特征點(diǎn)提取的方法。 3.對(duì)傳統(tǒng)的角膜復(fù)原方法進(jìn)行深入的分析探討,并提出一種基于精確定位角膜頂點(diǎn)的復(fù)原算法,通過引入單球面鏡反射公式求解第一反射點(diǎn)和角膜頂點(diǎn)的位置關(guān)系,以此精確定位角膜頂點(diǎn),在此基礎(chǔ)上計(jì)算了反射點(diǎn)的位置以及屈光度。通過建立屈光度數(shù)據(jù)場(chǎng)網(wǎng)格以及線性顏色編碼表,最終獲得屈光度偽彩圖。 4.在本文算法的基礎(chǔ)上,給出角膜局部數(shù)量化參數(shù)以及全局參數(shù)的計(jì)算方法。局部參數(shù)包括屈光度信息和高度信息,全局參數(shù)包括模擬角膜鏡讀數(shù)、表面不規(guī)則指數(shù)和表面規(guī)則指數(shù)。探討各種局部參數(shù)的特點(diǎn)以及適用場(chǎng)合,并且分析了全局參數(shù)的意義。 5.選用多個(gè)標(biāo)準(zhǔn)球?qū)Ρ疚乃惴ǖ木群头�(wěn)定性能進(jìn)行驗(yàn)證,結(jié)果表明本文算法精度優(yōu)于傳統(tǒng)的方法,并且適用于較大的屈光度范圍,滿足臨床要求。
[Abstract]:With the development of corneal surgery, corneal topographic system has become an indispensable equipment in ophthalmology diagnosis and treatment. Placido disc examination of corneal topography is the most widely used means of examination. It has the characteristics of high precision, low cost, simple structure and low sensitivity to noise. Compared with other methods, this paper is more suitable for clinical application. This paper focuses on the research and application of restoration algorithm of Placido disk inspection method, based on the traditional methods. A restoration algorithm based on accurate corneal vertex location is proposed, and a corneal topographic software system is developed on the basis of this algorithm. The main research work of this paper is as follows: 1. The structure and physiological characteristics of cornea were studied, and the history and development of corneal topography were introduced. 2. The key technology of corneal topographic map system is studied, the system principle and hardware structure are introduced, and the method of automatic alignment and auto-focusing in the process of corneal topographic image acquisition is described. The methods of image analysis and processing, including image preprocessing, center location and feature point extraction, are studied. 3. The traditional corneal restoration method is deeply analyzed and discussed, and an algorithm based on accurate location of corneal vertex is proposed. By introducing the single spherical mirror reflection formula to solve the position relationship between the first reflection point and the corneal vertex, the corneal vertex can be accurately located. On this basis, the position and diopter of the reflection point are calculated, and the pseudo-color diopter image is obtained by establishing the grid of refraction data field and the linear color coding table. 4. Based on this algorithm, the calculation method of corneal local quantization parameters and global parameters is given. The local parameters include refraction information and height information, and the global parameters include simulated corneal reading. The surface irregularity index and surface rule index are discussed. The characteristics and application of various local parameters are discussed, and the significance of global parameters is analyzed. 5. The accuracy and stability of the algorithm are verified by using several standard spheres. The results show that the accuracy of the proposed algorithm is superior to that of the traditional method, and it is suitable for a wide range of diopters and meets the clinical requirements.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2010
【分類號(hào)】：TP391.41;R779.6

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 牛彥敏;計(jì)算機(jī)輔助光學(xué)作圖系統(tǒng)中光路計(jì)算模型[J];重慶師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2005年02期

2 馬晨旭;許才軍;張瓊;茅盛;;引入變差函數(shù)的反距離加權(quán)法及應(yīng)用研究[J];大地測(cè)量與地球動(dòng)力學(xué);2010年01期

3 李新,程國棟,盧玲;空間內(nèi)插方法比較[J];地球科學(xué)進(jìn)展;2000年03期

4 樓越煥,何平安,謝海寧,彭羽翔,謝會(huì)驊;基于Hough變換算法的激光牛頓環(huán)中心提取方法[J];光電子技術(shù);2004年03期

5 曹茂永,郁道銀;高灰度分辨率圖像的偽彩色編碼[J];光學(xué)技術(shù);2002年02期

6 曹茂永,郁道銀;基于感知顏色空間的灰度圖像偽彩色編碼[J];光學(xué)技術(shù);2002年04期

7 李今秀;李均利;魏平;;基于梯度的醫(yī)學(xué)圖像偽彩色編碼[J];光學(xué)技術(shù);2008年04期

8 李泰儒;彭曉春;鄭國棟;徐林春;;反距離加權(quán)法流場(chǎng)矢量插值研究[J];華北水利水電學(xué)院學(xué)報(bào);2009年02期

9 瞿鈞;甘嵐;;梯度Hough變換在圓檢測(cè)中的應(yīng)用[J];華東交通大學(xué)學(xué)報(bào);2007年01期

10 孫亦南,劉偉軍,王越超,孫亦蓬;一種用于圓檢測(cè)的改進(jìn)Hough變換方法[J];計(jì)算機(jī)工程與應(yīng)用;2003年20期

相關(guān)碩士學(xué)位論文 前4條

1 呂振華;數(shù)字化角膜地形圖復(fù)原算法研究[D];南京理工大學(xué);2006年

2 毛臻;角膜地形測(cè)量中眼球定位跟蹤若干技術(shù)的研究[D];南京理工大學(xué);2007年

3 邵鋒;角膜地形圖測(cè)量裝置的技術(shù)研究[D];南京理工大學(xué);2008年

4 王菲;MRI腦部醫(yī)學(xué)圖像分割方法研究[D];山東科技大學(xué);2009年

，

本文編號(hào)：1485031