Browning Craig M, Mayes Samuel, Deal Joshua, Arshad Arslan, Mayes Samantha Gunn, Parker Marina, Rich Thomas C, Leavesley Silas J
Chemical and Biomolecular Engineering, University of South Alabama, AL 36688.
Systems Engineering, University of South Alabama, AL 36688.
Proc SPIE Int Soc Opt Eng. 2019 Feb;10871. doi: 10.1117/12.2510506. Epub 2019 Feb 27.
Hyperspectral imaging (HSI) is a spectroscopic technique which captures images at a high contrast over a wide range of wavelengths to show pixel specific composition. Traditional uses of HSI include: satellite imagery, food distribution quality control and digital archaeological reconstruction. Our lab has focused on developing applications of HSI fluorescence imaging systems to study molecule-specific detection for rapid cell signaling events or real-time endoscopic screening. Previously, we have developed a prototype spectral light source, using our modified imaging technique, excitation-scanning hyperspectral imaging (HIFEX), coupled to a commercial colonoscope for feasibility testing. The 16 wavelength LED array was combined, using a multi-branched solid light guide, to couple to the scope's optical input. The prototype acquired a spectral scan at near video-rate speeds (∼8 fps). The prototype could operate at very rapid wavelength switch speeds, limited to the on/off rates of the LEDs (∼10 μs), but imaging speed was limited due to optical transmission losses (∼98%) through the solid light guide. Here we present a continuation of our previous work in performing an in-depth analysis of the solid light guide to optimize the optical intensity throughput. The parameters evaluated include: LED intensity input, geometry (branch curvature and combination) and light propagation using outer claddings. Simulations were conducted using a Monte Carlo ray tracing software (TracePro). Results show that transmission within the branched light guide may be optimized through LED focusing lenses, bend radii and smooth tangential branch merges. Future work will test a new fabricated light guide from the optimized model framework.
高光谱成像（HSI）是一种光谱技术，它在很宽的波长范围内以高对比度捕获图像，以显示像素特定的成分。HSI的传统用途包括：卫星图像、食品分销质量控制和数字考古重建。我们的实验室专注于开发HSI荧光成像系统的应用，以研究快速细胞信号事件或实时内镜筛查的分子特异性检测。此前，我们利用改进的成像技术——激发扫描高光谱成像（HIFEX），开发了一种原型光谱光源，并将其与商用结肠镜耦合进行可行性测试。16波长LED阵列通过多分支固体光导组合，耦合到结肠镜的光学输入端。该原型以接近视频速率的速度（约8帧/秒）进行光谱扫描。该原型可以在非常快的波长切换速度下运行，受限于LED的开/关速率（约10微秒），但由于通过固体光导的光传输损耗（约98%），成像速度受到限制。在此，我们展示了之前工作的延续，即对固体光导进行深入分析以优化光强通量。评估的参数包括：LED强度输入、几何形状（分支曲率和组合）以及使用外包层的光传播。使用蒙特卡罗光线追踪软件（TracePro）进行了模拟。结果表明，通过LED聚焦透镜、弯曲半径和光滑的切向分支合并，可以优化分支光导内的传输。未来的工作将测试基于优化模型框架制造的新型光导。
