Quantitative dynamic evolution of physiological parameters of RBC by highly stable digital holographic microscopy

Digital holographic microscopy (DHM) is a powerful label-free imaging tool that provides three-dimensional (3D) quantitative information of a specimen. In this work, the evaluation of morphological and quantitative parameters of human red blood cells (RBCs) by a new single-shot common-path off-axis digital holographic microscopic system is demonstrated. The proposed system is accomplished by employing a wedge plat, silver-coated at its back surface, into the object beam path generating two beams: one from the front surface and another from the back surface of the wedge plate. One of the beams is spatially filtered by using a pinhole to completely erase the object information from it and serving the clean reference beam, which on interfering with the object beam, creates the hologram. The proposed system, owing to common-path configuration, offers higher temporal phase stability, therefore, making it more suitable for the investigation of small cell thickness fluctuation. Moreover, the system is simple, compact, less expensive, and less vibration sensitive. The measurements of morphological and quantitative parameters, and membrane fluctuations of the human RBCs by the proposed system are reported. The experimentally calculated parameters of the RBC are obtained in good agreement with their normal physiological range.