Research on Applications of Semiconductor Laser in Medical Fields

Abstract

Due to the advantages of semiconductor laser such as small body, light weight, long life span, high efficiency, it has been used widely in the medical fields. This paper firstly introduces the function mechanism of semiconductor laser, and then analyzes the special applications in ophthalmology department, surgery department, cosmetology department and stomatology department. Finally, the broad prospect of applications of semiconductor laser in medical fields is given to provide references to relevant researchers. Function Mechanism of Semiconductor Laser There are two main mechanisms of semiconductor lasers in medical applications:The first is bio-stimulation mechanism.Stimulus is a concept on the biological functions. According to the biological function, autonomic nerve reflex, Pavlov's molecular biology and the principle of theory, can think that the weak interaction between laser and organism, laser is a source of stimulation, and the organism has special feel for various stimuli. In vivo impulse caused by receptor for stimulation, afferent nerve endings, reach the reactor reaction. Response is excited or inhibited. The relative dose depends on the application of laser. Part of the proper dose of laser energy in certain organisms, as appropriate amount of stimulation answer in response to this, at the molecular level is to adjust the synthesis of protein and nucleic acid, DNA replication, regulation of enzyme function at the cellular level is the mobilization of compensation, nutrition, repair, and other immune defense mechanisms to eliminate the pathological process. The mechanism of laser bio stimulation is a reasoning hypothesis. In foreign countries, the weak laser bio-stimulation mechanism theory is inconsistent. A biological electric field hypothesis, light regulation system hypothesis, cell membrane receptor hypothesis and the hypothesis of the four polarization stimulation is not consistent with the hypothesis. This shows that the theory is not mature and need to be further discussed. The second mechanism is thermal effect. The thermal effect is the main factor of biological effect.It plays a role in all of the laser irradiation. High power semiconductor laser is mainly thermal effects of its application. Laser in biological tissue, tissue molecular absorption photon energy, the vibration and rotation increased, in the macro performance of the local irradiation becomes hot, high temperature. Because there exist such as melanin, hemoglobin, carotenoids and other pigments in the tissue cells, can increase the light absorption, so that the heat effect of laser is more significant. The interaction between laser and biological is a complicated process determined by various factors. The laser parameters such as wavelength, power, energy, coherence, polarization mode, laser modes have different effects on the biological tissue. The biological tissue properties such as density, elasticity, thermal conductivity, heat capacity, thermal diffusivity, reflectivity, absorption rate, pigment, moisture content, uniformity and hierarchical structure, also will make a different reflection of laser. In recent years, research on laser and biological interaction gradually, mainly discusses the absorption and scattering of laser tissue from theory and experiment, determine the temperature distribution and organization within the organization within the laser energy. From the macroscopic view, it is the study of human optical and laser. Its purpose is to achieve precise control and quantification of laser medical technology and to improve the clinical effect.