| There are two parts in this dissertation:1.the detection and control of diode laser therapeutic apparatus ;2.Effects of a single laser treatment on cutaneous wound healing: Biometrical and histological study in rabbits.Obiective: 1.To solve the problems of low power laser instrument with single wavelength and instable output power as well as its incapability of studying the biological effect of low intensity laser and clinical treatment,a new diode laser therapeutic apparatus is developed. 2.Theoretical and experimental reaserches were introduced in this dissertation. The purpose of this study was to investigate two power dose using a 650 nm diode laser to compare the healing of full-thickness cutaneous defects after a single laser treatment in a rabbit model,to find some suitable treatment parameter and to provide some useful data for other studies.Methods : 1.Accorrding to the design requiment of power adjusted continuously and the parameter of two wavelengths ,the AT89S52 singlechip and PID algorithm were used.To design the circuit diagram with Protel software,compeling with program,firing the COMS chips,building circuit diagram on breathboard,producing PCB board,designing appatatus'sface board,purchasing the electric elements and welding them. 2.For the present study, twenty-one adult male rabbits with body mass between 2kg and 2.5kg were used to contrast orperative wound models.They were divided into 3 groups randomly,including control group,5mW irradiation group and 10mW irradiation group. Biometry and light microscopy are used to investigate the effect of LILT on cutaneous wound healing.Results:1.The desired instrument could output the wave of 532nm green laser which could be adjusted continuously from 0mW to 16mW and the wave of 650nm red laser which could be adjusted continuously from 0mW to 50mW. The error of power could be controlled within 0.1mW. 2.It was showed by the animals experiment that there is a statistically significant difference among the groups regarding wound contraction. Significant differences were observed between 5mW irradiation group and control group at5d, 9d and 13d(P﹤0.05). On the same, 10mW irradiation group and control group presented similar values for wound contraction(P﹤0.05). However,5mW irradiation group didn't show significant differences compared to the 10mW irradiation(P﹥0.05).Conclusion:1.The instrument can be used to study the biological effect of low intensity laser and clinical treatment with small volume, easy operation , high stability and two wave lenths of laser output. The PID algorithm and close-loop control were used. 2.low-intensity laser therapy may provide acceleration of cutaneous wound healing in rabbits. A uniform exposure from a single irradiation with a laser emitting at 650 nm could be used to hasten the biological response in a conservative way. The effects were to some extend dependent upon the wavelength and the dose.There is no necessary relationship between the acceleration and the intensity. Whether the irradiation bring inhibition of the laser effects since a therapeutic window ,it is needed a further study. |
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