Stent implantation is a way to threat vessel, which has been calcified due to cardiovascular atherosclerotic diseases. The stent is a biocompatible mesh that is implanted to improve the permeability of the narrowed blood vessels.
In BME, Faculty of Mechanical Engineering, Department of Materials Science & Engineering there are ongoing researches related to medical devices more than twelve years ago. My actual researches are connected to the development of stent-system. My intention was to optimize the steps of surface treatment, so the treated stents become suitable for further use.
During my work 2×15 mm size 316 L stainless steel stents were used. In the first step the geometric properties of the laser-cutted stents were investigated by optical microscopy. Thereafter, the surface treatment of the stents was carried out. First, chemical etching was used to remove the burr caused by the laser cutting process. Then the etched stents were electropolished in order to improve the surface properties - reducing surface roughness, rounding the cutted edges. Geometric parameters of the treated stents were examined step by step, so I deduced the efficiency and reproducibility of surface treatment.
By the end of my experiments I found the optimum parameters for the steps of surface treatment - solution composition, time, temperature, etc. I crimped the developed surface-treated stent on balloon catheter. During the crimping I used two different crimping method. I also examined the properties of the different stent systems, in particular the stent – balloon catheter relationship.
During my Master Thesis I developed and described in details the method of the chemical etching and electropolishing. I created a stent system and I examined it. I evaluated the results of my measurement and I made a proposal for future research.