Chen Xiaoya, Luo Peng, Hu Chuanzhen, Yan Shaojie, Lu Dapeng, Li Yaning, Chu Kaiqin, Smith Zachary J
Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui, China.
Department of Clinical Laboratory, The First Affiliated Hospital of University of Science and Technology of China, Hefei, China.
Biomed Opt Express. 2020 Sep 28;11(10):5950-5966. doi: 10.1364/BOE.405510. eCollection 2020 Oct 1.
Because of the bulk, complexity, calibration requirements, and need for operator training, most current flow-based blood counting devices are not appropriate for field use. Standard imaging methods could be much more compact, inexpensive, and with minimal calibration requirements. However, due to the diffraction limit, imaging lacks the nanometer precision required to measure red blood cell volumes. To address this challenge, we utilize Mie scattering, which can measure nanometer-scale morphological information from cells, in a dark-field imaging geometry. The approach consists of a custom-built dark-field scattering microscope with symmetrically oblique illumination at a precisely defined angle to record wide-field images of diluted and sphered blood samples. Scattering intensities of each cell under three wavelengths are obtained by segmenting images via digital image processing. These scattering intensities are then used to determine size and hemoglobin information via Mie theory and machine learning. Validation on 90 clinical blood samples confirmed the ability to obtain mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW) with high accuracy. Simulations based on historical data suggest that an instrument with the accuracy achieved in this study could be used for widespread anemia screening.
由于体积、复杂性、校准要求以及对操作人员培训的需求，目前大多数基于流动的血细胞计数设备都不适合现场使用。标准成像方法可能更加紧凑、廉价，且校准要求极低。然而，由于衍射极限，成像缺乏测量红细胞体积所需的纳米精度。为应对这一挑战，我们在暗场成像几何结构中利用米氏散射，它能够测量细胞的纳米级形态信息。该方法包括一台定制的暗场散射显微镜，以精确设定的角度进行对称斜照，以记录稀释并呈球形的血液样本的宽视野图像。通过数字图像处理对图像进行分割，可获得每个细胞在三个波长下的散射强度。然后，利用米氏理论和机器学习，通过这些散射强度来确定细胞大小和血红蛋白信息。对90份临床血液样本的验证证实了该方法能够高精度地获取平均红细胞体积（MCV）、平均红细胞血红蛋白浓度（MCHC）和红细胞分布宽度（RDW）。基于历史数据的模拟表明，具有本研究中所达到精度的仪器可用于广泛的贫血筛查。
