Mechanical Model for Evaluating Curative Effect of Laser on Hypertrophic Scar / 医用生物力学

ABSTRACT

Objective To establish a mechanical model with times of laser treatment as the independent variable in treatment process of rabbit ear hypertrophic scar (HPS) by combining experimental research and numerical simulation, so as to evaluate the curative effect of HPS. Methods Firstly, the HPS model of rabbit ear was established by CO2 laser instrument, and then the HPS was treated for continuous three times by pulsed dye laser (PDL) combined with CO2 lattice laser. After each treatment, the uniaxial compressive mechanical properties of HPS were tested to fit Ogden hyperelastic model to obtain mechanical parameters of HPS during the treatment. The functional relationship between mechanical parameters of HPS and times of laser treatment was established by LM optimization algorithm. Results Mechanical parameters of HPS increased with the increase of laser treatment times, and gradually became a constant, namely, mechanical parameters of normal skin. With the increase of laser treatment times, the growth ratio of HPS mechanical parameters gradually decreased. The initial growth ratio was 60% and decreased to 4.09% after three times of treatment. Conclusions The initial curative effect of laser therapy is the most obvious, and with the relief of symptoms, the effect of single laser therapy is no longer significant.