基於場可程式化邏輯閘陣列的光譜域光學相干斷層掃描（SD-OCT）系統：設計與實現

Abstract

譜域光學相干斷層掃描（SD-OCT）是一種用於生物醫學領域檢測眼科病理的光學成像技術。然而，由於儀器中集成了複雜的電子設備，當前的SD-OCT系統通常價格昂貴且體積龐大。為了解決這一限制，研究人員現在專注於設計便攜式且方便的SD-OCT系統。本研究的目的是開發一種便攜式SD-OCT系統，利用基於FPGA的影像處理算法來產生B-mode的OCT圖像。為了實現高便攜性和可訪問性，採用了自製的影像擷取模組。我們實作出本文所提出的影像處理演算法，而用到的FPGA資源，LUT、LUTRAM、FF、DSP、BUFG的使用率都是低於5%。實際使用此SD-OCT系統進行影像演算法處理，結果顯示我們的SD-OCT系統拿取簡易麥克森干涉儀的干涉光譜進行影像處理，具有與商業用SD-OCT相當的靈敏度，同時軸向解析度可達5.9μm。此外，我們還將其與商業用SD-OCT進行成像比較，PSNR值為21 dB，SSIM為0.74，這意味著這兩幅影像的成像品質在結構和紋理方面相對接近。該研究證明了通過FPGA訪問原始數據來構建具有1000多次A-scan的單個B-mode OCT圖像的可行性。換句話說，我們成功地開發了一種便攜式SD-OCT系統，並通過FPGA影像處理算法獲得高品質的OCT圖像，這為未來在生物醫學領域的眼科病理檢測提供了潛在的低成本和便攜式解決方案。

Spectral Domain Optical Coherence Tomography (SD-OCT) is an optical imaging technique used in the field of biomedical sciences to detect ocular pathologies. However, due to the integration of complex electronic components, current SD-OCT systems are often expensive and bulky. To address this limitation, researchers are now focusing on designing portable and convenient SD-OCT systems. The aim of this study is to develop a portable SD-OCT system that utilizes FPGA-based image processing algorithms to generate B-mode OCT images. To achieve high portability and accessibility, a custom-made image acquisition module was adopted.We implemented the proposed image processing algorithms in this study, and the FPGA resource utilization, including LUT, LUTRAM, FF, DSP, and BUFG, all remained below 5%. Through practical application of this SD-OCT system for image processing, the results demonstrated that our spectral-domain optical coherence tomography system, using the homemade image acquisition module and processing interference spectra from a simple Mach-Zehnder interferometer, achieved sensitivity comparable to commercial SD-OCT systems, with an axial resolution of up to 5.9 μm. Furthermore, we compared our system to a commercial SD-OCT for imaging, yielding a PSNR value of 21 dB and an SSIM of 0.74, indicating that the image quality of these two sets of images was relatively close in terms of structure and texture.This study demonstrated the feasibility of building a single B-mode OCT image with over 1000 A-scans using FPGA to access the raw data. In other words, we successfully developed a portable SD-OCT system and obtained high-quality OCT images through FPGA-based image processing algorithms, which provides a potential low-cost and portable solution for future ocular pathology detection in the field of biomedical sciences.