Significance: Spatial frequency domain imaging (SFDI) is a wide-field imaging technique that provides quantitative maps of tissue optical properties. We describe a compact SFDI imager that employs a multispectral compound-eye camera. This design enables simultaneous image acquisition at multiple wavelengths. Such a device has potential for application for quantitative evaluation of superficial tissues by nonspecialists in low-resource settings. Aim: The aim of this work was to develop a compact SFDI imager for widefield imaging of in-vivo tissue optical properties and verify its ability to measure optical properties of tissue-simulating phantoms and in a preclinical model of burn wounds. Approach: This compound-eye imager was constructed using a CMOS sensor subdivided into multiple regions, each having a bandpass filter and objective lens. The ability of the instrument to image optical properties was compared with (1) a commercial SFDI imager and (2) a laboratory-based system. Initial validation of ability to accurately characterize optical properties was performed using a tissue-simulating optical phantom. It was then applied to an established murine model of thermal contact burn severity. In-vivo measurements of the optical properties of rat skin were performed before and after the application of burns. Histology was used to verify burn severity. Results: Measurements of the tissue-simulating phantom optical properties made using the compound-eye imager agree with measurements made using the two comparison SFDI devices. For the murine burn model, the burns showed a decrease in the reduced scattering coefficient at all measurement wavelengths compared with preburn measurements at the same locations. This is consistent with previously reported changes in scattering that occur in full-thickness burns. Conclusion: We demonstrate the potential for SFDI to be translated into compact form factor using a compound-eye camera that is capable of obtaining multiple wavelengths channels simultaneously.

中文翻译：

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基于紧凑型多孔径相机的空间频域成像仪：无创烧伤严重程度评估的测试和可行性

意义：空间频域成像 (SFDI) 是一种广域成像技术，可提供组织光学特性的定量图。我们描述了一种采用多光谱复眼相机的紧凑型 SFDI 成像仪。这种设计可以同时采集多个波长的图像。这种设备有可能在资源匮乏的环境中由非专家对浅表组织进行定量评估。目的：这项工作的目的是开发一种紧凑型 SFDI 成像仪，用于体内组织光学特性的宽场成像，并验证其测量组织模拟模型和烧伤临床前模型的光学特性的能力。方法：这种复眼成像仪是使用细分为多个区域的 CMOS 传感器构建的，每个区域都有一个带通滤波器和物镜。该仪器对光学特性成像的能力与 (1) 商用 SFDI 成像仪和 (2) 实验室系统进行了比较。使用组织模拟光学模型对准确表征光学特性的能力进行了初步验证。然后将其应用于已建立的热接触烧伤严重程度的小鼠模型。在应用烧伤前后对大鼠皮肤的光学特性进行体内测量。组织学用于验证烧伤严重程度。结果：使用复眼成像仪进行的组织模拟幻影光学特性测量与使用两个比较 SFDI 设备进行的测量一致。对于小鼠烧伤模型，与相同位置的预烧测量相比，烧伤显示所有测量波长的散射系数降低。这与先前报道的全层烧伤中发生的散射变化一致。结论：我们展示了使用能够同时获取多个波长通道的复眼相机将 SFDI 转化为紧凑外形的潜力。