Research On Laser Interference Processing Of Coronary Stents

Coronary heart disease has become one of the important causes of human death,and the current clinical treatment has a high long-term restenosis rate and is easy to form late stent thrombosis.In recent years,studies have shown that the hydrophobic surface with regular geometric structure is beneficial to reduce the formation of restenosis and late thrombosis..Based on the analysis of multi-beam laser interference theory,the mathematical physics models of double-beam,three-beam and four-beam laser interference were established,and the simulation results were analyzed by software.The parameters influencing the interference result were also analyzed.Based on the theoretical analysis and simulation,a three-beam laser interference system was constructed.In this system,the laser source was a solid-state high-power pulsed Nd:YAG laser with the wavelength of 1064 nm.The laser beam was split into three beams by the beam-splitter and reflector to form three-beam interference.By adjusting the laser incident angle,the highly ordered concave structures with several different periods were fabricated on the coronary artery stent surface.The morphology and contact angle of the micro/nano structure were measured with scanning electron microscopy and contact angle measuring instrument.The period of the micro/nano structure was between 5 μm and 20 μm,and the contact angle can reached 120.5° when the period is 5 μm.The experimental results showed that the processing technology of multi-beam laser interference can improve the hydrophobicity of the coronary stent,which can be used to solve the problem of restenosis and late thrombosis.