Skin Measurements and Analysis on Dynamic Properties Using Mirau-based Full-field Optical Coherence Tomography

　　In this thesis, Mirau-based full-field optical coherence tomography system using homemade Ti:sapphire crystal fiber amplified spontaneous emission (ASE) as light source was demonstrated. The lateral and axial resolution of the system are 1.25 μm and 1.3 μm in tissue, respectively. High-resolution in-vivo human skin images acquired from various locations such as dorsal forearm, palm, finger and wrist were demonstrated. Besides the morphology, dermal-epidermal junction, sweat gland, pore and vessel could be found out. The stratum corneum thickness was compared between above locations. It is about 300 μm, the thickest, at thumb and about 4 μm, the thinnest, at wrist. Complementary to the morphology extracted with OCT system, orthogonal polarization spectral imaging (OPSI) was used to study the dynamic properties of red blood cells (RBC). Due to the absorption difference, RBC under OPSI has different appearance. At 560 nm, higher absorption, RBC is a black dot. At 780 nm, lower absorption, the boundary of RBC can be seen, but not that obvious compare with the circumstances of 560 nm. Finally, RBC velocity calculation was demonstrated with particle image velocimetry (PIV) method using cross-correlation algorithm. Using regional standard deviation, RBC flowing region can be found out. The RBC velocity of capillary is about 30 - 80 μm/s, and that in small vessel is at the range of 70 – 100 μm/s. Skin morphology acquired from OCT system combined with dynamic properties studied by OPSI and PIV may provide assistance for skin diseases related with structural change and RBC velocity change.