Abstract: The damage effects and repair rules of pig skin tissue after different doses of 1 064 nm laser irradiation were explored, so as to provide guidance for expanding the safe application of laser in clinical practice. This article used a fundamental mode fiber laser to output 1 064 nm continuous laser with different powers. Live pig skin was irradiated at multiple spots one time by using a grid-array method. The skin injury reaction was observed and its incidence was calculated immediately after laser irradiation from low to high doses. The weighted probit method was used to calculate the damage threshold ED50. The healing and pathological changes after laser-induced skin injury were observed dynamically within 6 h and for 28 d after laser irradiation. With the increase of irradiation dose, laser-induced skin injuries ranging from mild to severe appeared erythema, white spot and burnt spot in turn. When the dose was lower than 70.0 J/cm2, a reversible erythema predominantly occurred. When the dose was 192.2 J/cm2, a burnt spot predominantly occurred with an incidence of about 51.4 %. However, the incidence of burnt spots could reach 100.0% at a dose of 425.0 J/cm2. The damage threshold ED50 of pig skin damage caused by a 1 064 nm laser is 50.8 J/cm2. 3～28 d after irradiation, pathomorphological results showed that the wounds of each irradiation group appeared varying degrees of repair trend. However, this trend tended to be weakened with the increase of laser irradiation intensity, and the recovery trend of laser irradiation groups higher than 192.2 J/cm2 was slow. After irradiation with the 1 064 nm laser on pig skin, the higher the laser irradiation dose is, the more serious the skin injury is and the slower the wound repair is, indicating a good dose-effect correlative relationship. This study provides an important experimental and theoretical basis for the medical application of laser irradiation-induced skin injury and repair process.
Key words: 1 064 nm laser; miniature pig; skin damage threshold; skin damage effects; repair
（Acta Laser Biology Sinica, 2023, 32(4): 312-320）