基於影像分析建立 手持式角膜地形儀系統之研究;Study of Handheld Corneal Topographer by Image Analysis Method

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/79460

Title:	基於影像分析建立手持式角膜地形儀系統之研究;Study of Handheld Corneal Topographer by Image Analysis Method
Authors:	張維勳;Chang, Wei-Hsun
Contributors:	光電科學與工程學系
Keywords:	角膜地形儀;Placido disc
Date:	2019-01-15
Issue Date:	2019-04-02 14:27:49 (UTC+8)
Publisher:	國立中央大學
Abstract:	本研究主要目的為設計一款輕型的眼角膜表面曲率檢測系統，透過光學檢測與軟體運算，得知眼角膜表面的曲率變化。此系統包含前段特殊照明燈罩、相機，及後段電腦與MATLAB。本研究設計之角膜地形儀主要是使用Placido disc非等間距同心圓照明投影並拍攝影像，搭配MATLAB軟體運算得出計算結果，以同心圓紋路投影於角膜，並透過成像鏡頭由CMOS Sensor觀察紋路投影於角膜的狀態，藉由分析影像紋路的密度得知角膜各處的曲率分佈。透過特定形狀的照明燈罩以及簡化的光源優化元件，結合適當成像鏡頭以及感測元件取得影像，藉由軟體模擬以及演算設計，製成手持式角膜地形儀，改善目前角膜地形儀體積大，設備成本高的缺點。目前市面體積最小的角膜地形儀以手持測試模組連接電腦呈現，手持部分尺寸約為25x12x12cm、3600cm³，而本研究鏡頭尺寸為9x6.5x6.5cm、主機為20x9x4cm，總體積約1100cm³，為市售產品體積的30%，而跟一般桌上型角膜地形儀(30x30x50cm)相比更是只有3%的體積，更加適合攜帶及手持使用。初步模擬驗證辨識精度為±0.5D，距離±0.1D的目標尚有一段距離。 ;The main purpose of this paper is to design a lightweight corneal surface curvature detection system to detect the curvature change of the corneal surface through optical detection and software calculation. The system includes a special lighting cover, camera, and computer with MATLAB. The corneal topographer designed in this paper uses Placido disc illumination to project and record images, and uses MATLAB software to calculation the results. The concentric circle is projected onto the cornea, The pixel projection state of the CMOS sensor on the cornea is observed through an imaging lens. By analyzing the density of the image texture, that we can know the curvature distribution of the entire cornea. Use the simplified design illumination, lens modules, and calculation. A cheaper, effective, handheld corneal topographer will be achieve. Special design make the size is 30% of similar products. And 3% of general products.
Appears in Collections:	[Graduate Institute of Optics and Photonics] Electronic Thesis & Dissertation

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