Design of a source-detector array for dual-slope diffuse optical imaging.
Design of a source-detector array for dual-slope diffuse optical imaging.
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DOI：
10.1063/5.0015512
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Giles Blaney;A. Sassaroli;S. Fantini
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文献类型：
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作者：
Giles Blaney;A. Sassaroli;S. Fantini
最近，我们提出了一种双斜率散射介质的散射光谱和成像技术。这种技术需要特殊配置的光源和光学检测器来创建双斜率集。在这里，我们提出了设计，优化和建立一个光学成像阵列，具有m双斜率集图像n体素的方法。在定义了描述m个双斜率测量对n个体素中的每个体素的吸收扰动的灵敏度的m × n矩阵（S）之后，我们用S（S+）的Moore-Penrose伪逆矩阵来表示逆成像问题。这种方法允许我们引入几种成像性能的测量：重建精度（正确的空间映射），串扰（不正确的空间映射），分辨率（点扩散函数）和定位（实际和重建点扰动之间的偏移）。此外，通过考虑奇异值分解公式，我们展示了可视化S的前m个右奇异向量的意义，其线性组合生成重构映射。我们还描述了使用嵌入硅树脂（PDMS）中的三层网状结构（两层聚乙烯薄膜和聚丙烯钩环织物）构建物理阵列的方法。最后，我们应用这些方法来设计两个数组，并选择一个来构造。所选择的阵列由16个照明光纤，10个检测光纤，和27个双斜率集的双斜率成像优化的视野和本地化的吸收扰动的大小。这个特殊的阵列是针对人脑的功能性近红外光谱，但这里提出的方法是普遍适用于各种设备和成像场景。
We recently proposed a dual-slope technique for diffuse optical spectroscopy and imaging of scattering media. This technique requires a special configuration of light sources and optical detectors to create dual-slope sets. Here, we present methods for designing, optimizing, and building an optical imaging array that features m dual-slope sets to image n voxels. After defining the m × n matrix (S) that describes the sensitivity of the m dual-slope measurements to absorption perturbations in each of the n voxels, we formulate the inverse imaging problem in terms of the Moore-Penrose pseudoinverse matrix of S (S+). This approach allows us to introduce several measures of imaging performance: reconstruction accuracy (correct spatial mapping), crosstalk (incorrect spatial mapping), resolution (point spread function), and localization (offset between actual and reconstructed point perturbations). Furthermore, by considering the singular value decomposition formulation, we show the significance of visualizing the first m right singular vectors of S, whose linear combination generates the reconstructed map. We also describe methods to build a physical array using a three-layer mesh structure (two polyethylene films and polypropylene hook-and-loop fabric) embedded in silicone (PDMS). Finally, we apply these methods to design two arrays and choose one to construct. The chosen array consists of 16 illumination fibers, 10 detection fibers, and 27 dual-slope sets for dual-slope imaging optimized for the size of field of view and localization of absorption perturbations. This particular array is aimed at functional near-infrared spectroscopy of the human brain, but the methods presented here are of general applicability to a variety of devices and imaging scenarios.