Digital Optical and Scanning Probe Microscopy for Inspection and Manipulation of Biocells - Bioanalysis Advanced Materials Methods and Devices - page 93

more elastic than for men. At the same time E in men with DM-2 was higher
than in healthy males, that is that this pathological condition makes the

erythrocytes more rigid.
Turning to lung research, estimation of the difference in mechanical properties
between human embryonic fibroblasts cells and the cells of human lung adenocarci-
noma cell line (A549) showed that the apparent elastic modulus of human embry-
onic fibroblasts cells were 1.4 times higher than that of A549 cells at the significance
level p

2.45 kPa, respectively) [ 42 ].
Therefore, the membranes of lung cancer cells are more elastic than that of normal
fibroblasts, which is in accordance to published data [ 43 , 44 ]. This result also means
that the cytoskeleton structure of cancer cells differs from that of normal cells.

< 0.001 (260.21 5.84 kPa and 184.31

7.6 Blood Flow in the Microcirculation:
Laser Monitoring of Biotissues

7.6.1 Biospeckle Pattern Formation

A biospeckle pattern is produced by 3D interference of probing laser coherent
light multiply scattered by the erythrocytes flowing inside living tissues, as in
Fig. 7.1 (right).
Detailed analysis of multiple scattering on biospeckle formation and its dynam-
ics shows that the time-space cross-correlation analysis of the temporal evaluation
of the biospeckle patterns is an effective means of real time flow and stress
visualization of a living tissue. Digital processing of biospeckle patterns records
yields 2D maps which exhibit the temporal and spatial variations in flowing
erythrocytes.

7.6.2 Monitoring of Biotissues by Dynamic Speckle
Pattern Analysis

Planar Laser Speckle Photography or Particle Image Velocimetry (PIV) became a
standard method for the determination of a fluid velocity map within a selected
plane illuminated by a laser beam [ 13 ]. However, in many important applications it
is difficult to illuminate the area of interest by a thin laser sheet. One of such
applications is in vivo subskin blood flux velocimetry, when it is impossible to
implement traditional PIV illumination. In such studies one deals with a volume
illumination, at least due to the multi-scattering effects and the PIV technique may
be combined with speckle photography methods as reported in [ 13 ]. Monitoring of
the activity of the blood in the microcirculation in living tissues is of considerable
importance for many diagnostic purposes. The microcirculation fulfills the function