Embedded Control Of Medical Long Pulse Laser

In 1983,American doctor Anderson and Parrish developed the theory of'selective Photothermolysis', which was regarded as the foundation of pigmented removal and treating cutaneous vascular lesions with laser. Later the theory of'Thermal Kinetics Selectivity'is the foundation of laser hair removal. The design plan of long-pulse dual wavelength laser system has been brought forward, which consists of 1064nm and 755nm two wavelengths laser. The 1064nm infrared laser could be used to hair removal, vascular treatment, facial rejuvenation and fine wrinkle. And the 755nm laser can do hair removal and pigmented treatment. In order to meet the actual demand of clinic, the pulse width and energy of this two laser both could be adjusted in a certain field.In this thesis, the development and current situation of medical laser and cutaneous laser have been introduced first, then the embedded control system design of this medical long pulse dual wavelengths laser has been presented. The pivotal and difficult technology have been analyzed yet. Accordingly the resolutions to the problems said above have been brought forward, which were demonstrated as follows:1) The new switch device IGBT was used as the DC chopper of the Xenon flashlamp discharge circuit, and the traditional single long pulse was replaced by quasi-continuous long pulse bursts. Controlling the driving signal of IGBT, the pulse width and energy of long pulse burst can be adjusted easily .we selected the specific driving chip HCPL316J as IGBT driver, and designed a circuit to eliminate the surge voltage of IGBT.2) We selected the Rabbit 2000 MCU as control core of laser control unit. We design and study hardware like the A/D, D/A, Serial port, Keypad and LCD in this laser control unit system. We also design and study the software like main program, initial program and interrupt vector installation based on the Dynamic c integration program environment3) We do analyze the anti-jamming on the control unit circuit and do final test for the laser control system.4) We brought forward a laser medical diagnosis expert system based on CBR(case based reasoning).This medical diagnosis expert system can recommend to the doctor to help therapy after optimizing.