Significance: Placenta is an essential organ for fetal development and successful reproduction. Placental insufficiency can lead to fetal hypoxia and, in extreme cases anoxia, leading to fetal death. Of the 145 million deliveries per year worldwide, ∼15 million neonates are small for gestational age and, therefore, at risk for antepartum and intrapartum hypoxia. Clinical methods to assess placental function largely rely on the assessment of fetal heart rate changes but do not assess placental oxygenation. Near-infrared spectroscopy (NIRS) allows non-invasive, real-time assessment of tissue oxygenation in intact organs, which can be used to assess placental oxygenation. However, tissue optical properties can affect the accuracy of methods to measure tissue oxygenation. Aim: This study was performed to estimate the scattering coefficient of the human placenta. We have computed the scattering coefficients of the human placenta for the range of 659 to 840 nm using two methods of diffuse reflectance spectroscopy (DRS). Approach: Measurements were performed using an in-house DRS device and a well-established frequency-domain diffuse optical spectroscopic system (DOSI). Measurements were performed in eight placentas obtained after cesarean deliveries. Placentas were perfused with normal saline to minimize the effects of absorption due to blood. Three sites per placenta were measured. Absorption and scattering coefficients were then calculated from the measured reflectance using the random walk theory for DRS and frequency-domain algorithm for DOSI. Results: Average reduced scattering coefficient (μs ′ ) was 0.943 ± 0.015 mm − 1 at 760 nm and 0.831 ± 0.009 mm − 1 at 840 nm, and a power function μs ′ = 1.6619 (λ/500 nm) − 1.426 was derived for the human placental scattering coefficient. Conclusion: We report for the first time the scattering coefficient of the human placenta. This information can be used to assess baseline scattering and improve measurements of placental oxygen saturation with NIRS.

中文翻译：

---

使用连续波和频域漫反射光谱评估人类胎盘的光学散射特性

意义：胎盘是胎儿发育和成功繁殖的重要器官。胎盘功能不全会导致胎儿缺氧，在极端情况下还会导致胎儿缺氧。在全世界每年 1.45 亿分娩中，约 1500 万新生儿小于胎龄，因此有产前和产时缺氧的风险。评估胎盘功能的临床方法主要依赖于对胎儿心率变化的评估，但不评估胎盘氧合。近红外光谱 (NIRS) 允许对完整器官中的组织氧合进行非侵入性实时评估，可用于评估胎盘氧合。然而，组织光学特性会影响测量组织氧合的方法的准确性。目的：进行这项研究是为了估计人类胎盘的散射系数。我们已经使用两种漫反射光谱 (DRS) 方法计算了 659 到 840 nm 范围内人类胎盘的散射系数。方法：使用内部 DRS 设备和完善的频域漫射光谱系统 (DOSI) 进行测量。在剖宫产后获得的八个胎盘中进行了测量。用生理盐水灌注胎盘，以尽量减少血液吸收的影响。测量每个胎盘的三个位点。然后使用 DRS 的随机游走理论和 DOSI 的频域算法从测量的反射率计算吸收和散射系数。结果：平均减少散射系数 (μs ' ) 为 0.943 ± 0。760 nm 处为 015 mm - 1，840 nm 处为 0.831 ± 0.009 mm - 1，并且推导出人类胎盘散射系数的幂函数 μs ' = 1.6619 (λ/500 nm) - 1.426。结论：我们首次报道了人类胎盘的散射系数。该信息可用于评估基线散射并改进 NIRS 对胎盘氧饱和度的测量。