Influence of red laser irradiation on hemoglobin oxygen saturation and blood volume in human skin in vivo

Abstract

The aim of the present work was to study the response of hemoglobin oxygen saturation and relative blood volume in human skin in vivo to laser irradiation. The hemoglobin oxygen saturation and relative hemoglobin concentration in skin were evaluated from diffuse reflectance spectra in visible wavelength range. The skin spot at human hand was irradiated with laser beam and hemoglobin oxygen saturation and relative hemoglobin concentration were sampled every two second from the center of irradiated spot. It was evidently observed that hemoglobin oxygen saturation is increased after starting irradiation. During occlusion the oxygen consumption rate was higher in the presence of laser irradiation. However these effects were observed only at sufficiently high laser fluence rates. The most probable reason is that it is due to thermal effects.

Reduction of thermal damage in photodynamic therapy by laser irradiation techniques

“…This method does not have the side effects such as decreased immunity, hair loss, pain, or mutations that can accompany conventional cancer treatments such as chemotherapy, surgery, or radiotherapy. [1][2][3][4][5][6][7] In addition, PDT has the advantage of being selective for cancer tissues, while organs and normal tissues are preserved in their original state. [8][9][10][11][12] The density of photosensitizers (PS) in a tumor, the excited photometric quantities injected into the tissue, and the amount of molecular oxygen in the organic tissue are factors that affect the results of photodynamic cancer treatment.…”