Fig. 1. Optical layout of digital holography.

Fig. 2. Optical layout of digital holographic reconstruction.

Fig. 3. Inline digital holographic microscopic system for detecting micro-deformation of RBC^[52].

Fig. 4. The relationship between the RBC deformation and the real part of reconstructed amplitude. (a) The reconstruction distance z' to the focus at different recording distances z of the simulated RBC (red) and the experiment using a real RBC (green). Inset shows the Cassini model of the RBC used in the simulations; (b) the experiment using a real RBC (green), the reconstructed Re(U) for the simulated unaltered RBC and a deformed RBC represented by the red and blue curves, respectively; (c) reconstructed data from a ~20% smaller RBC compared with the one used in (b). Red and green curves represent the Re(U) of simulation and experiment, respectively; Gray vertical line in (b) and (c) indicates position of the RBC^[52].

Fig. 5. Inline digital holographic microscopic system for tracking spatial distribution of RBCS^[51].

Fig. 6. The hologram and the reconstruction images of RBCs. (a) The RBC hologram obtained from CMOS; (b), (c), and (d) represent RBC reconstruction images at different reconstruction depths, respectively. Each focused RBC is shown by an arrow^[51].

Fig. 7. Off-axis digital holographic microscopy system for measuring RBCs’ three-dimensional volume of different shapes^[54].

Fig. 8. The reconstructed phase image for RBCs (a) The reconstructed phase image for RBCs having a stomatocyte shape; (b) the reconstructed RBCs phase image for RBCs having a discocyte shape; (c)the segmented phase image for RBCs having a stomatocyte shape; (d) the segmented phase image for RBCs having a discocyte shape; (e) the segmented phase image for single RBC(f), (g) and (h) represent the A, B and C parts by the marker-controlled watershed algorithm in RBC, respectively^[54].

Fig. 9. Off-axis digital holographic microscopy system for investigating the effect of defocus on RBC three-dimensional volume measurement^[53].

Fig. 10. Digital refocusing of a single red blood cell image and corresponding optical volume measurements. (a) The amplitude and phase images by the manually-focused method and digitally-refocused method from a single RBC; (b) amplitude variance metric of holograms A-G; (c) computed OV of RBC from manually-focused phase images(black) and digitally-refocused phase images(blue). OV reported as mean ± standard deviation^[53].

Fig. 11. Off-axis digital holographic microscopy system with optical tweezer for measuring RBCs’ three-dimensional volume^[72].

Fig. 12. Height change of reconstructed RBCs under different concentrations of oxidative stress (0−200 μmol/L). Four images in each group are corresponding to trap force varying from 0−3 pN. Color bar represents different thickness^[72].

Fig. 13. Performance of RBC under different oxidative stress. (a) The relationship between the maximum height H of RBC and the trap tensile force under different oxidative stress; (b) the volume of RBC under different oxidative stress^[72].