可降解心脏支架的飞秒激光精密加工

Femtosecond laser precision machining of biodegradable heart stent

以激光精密加工金属血管心脏支架生产工艺为基础,探索了可降解心脏支架的飞秒激光精密加工方式。利用飞秒激光的超短脉冲和超高峰值功率的特性,实现了以聚乳酸(PLA)为材料的可降解心脏支架的激光精密加工。设计了椅形衬套,稳定了激光焦斑位置,分析得出了最佳衬套离焦距用于配合飞秒激光精密加工。通过调试工艺参量,解决了由于材料本身特性引起的切缝边缘易炭化和加工过程中由于离焦量和焦斑位置准确度不稳定导致不能精密加工的问题,实现了对非金属可降解心脏支架的无热精密加工。说明了飞秒激光配合椅形衬套加工非金属血管支架的可行性,确定了最佳加工参量,加工出了无热损伤切边光滑筋宽一致性为±6μm的可降解心脏支架样品。

On the basis of the traditional laser precision machining technologies for metal heart stents, a femtoseconds（fs） laser precision machining technology for a degradable heart stent was explored. By using the ultra-short pulse and ultra high peak power of the fs laser, the laser precision machining was implemented for the degradable heart stent made from the polylactic acid （PLA）. A chair shaped bushing was designed to stabilize the laser focal spot position and the best bushing from focal precision machining was obtained to match with fs laser machining. By adjusting technological parameters, the shortcomings of the cutting edge carbonization caused by the characteristics of the material itself and the lower machining precision due to the unstable defocusing and focal spot position were overcome, and a nonmetal degradable heart stent method in a 11o heat precision machining was proposed. Finally, the feasibility of fs laser with chair-shaped bushing to machine a nonmetallic stent was described, the best machining parameters were determined, and a biodegradable stent sample without heat injury trimming and with a smooth band width consistency of ± 6 μ m was machined successfully.