J Biomed Opt. 2011 Dec;16(12):120505. doi: 10.1117/1.3662459.
Optical reflectance probes are often used as tools to obtain optical spectra from superficial tissues and subsequently determine optical and physiological properties associated with early stage cancer. These probes, when placed directly on the tissue, are known to cause significant pressure-dependent changes in local optical properties. To address this, we fit the probe with an optical device that images the illumination and collection fibers onto the tissue surface, eliminating the influence of contact probe pressure on the sampling area. The noncontact probe addition addresses new optical conditions that may affect its performance such as tissue surface contour, and specular reflections by implementing an autofocusing mechanism and cross polarization. Extracted optical properties of tissue simulating phantoms yield errors of 3.46% in reduced scattering and 8.62% in absorbance. Autofocusing has extended the depth of field from 4 mm to throughout the 12 mm range of autofocus travel, while cross polarization has removed the incidence angle dependent specular reflection component from the collected signal.
光学反射探头通常被用作从浅层组织获取光学光谱的工具，并随后确定与早期癌症相关的光学和生理特性。这些探头直接放置在组织上时，已知会导致局部光学特性发生显著的压力依赖性变化。为了解决这个问题，我们在探头中安装了一种光学设备，将照明和收集光纤成像到组织表面上，消除了接触探头压力对采样区域的影响。非接触探头的添加解决了新的光学条件可能会影响其性能的问题，例如组织表面轮廓和镜面反射，通过实施自动对焦机制和交叉偏振。组织模拟体模的提取光学特性在散射减少方面产生了 3.46%的误差，在吸收方面产生了 8.62%的误差。自动对焦将景深从 4 毫米扩展到整个 12 毫米的自动对焦行程范围，而交叉偏振则从收集的信号中去除了入射角相关的镜面反射分量。
