Three-dimensional printed 316L stainless steel cardiovascular stent's electrolytic polishing and its mechanical properties / 生物医学工程学杂志

The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0-10 µm size. Electrolytic polishing was performed to improve the surface quality of the printed vascular stent, and the expansion behavior of the polished stent was assessed by balloon inflation. The results showed that the newly designed cardiovascular stent could be manufactured by 3D printing technology. Electrolytic polishing removed the attached powder and reduced the surface roughness Ra from 1.36 µm to 0.82 µm. The axial shortening rate of the polished bracket was 4.23% when the outside diameter was expanded from 2.42 mm to 3.63 mm under the pressure of the balloon, and the radial rebound rate was 2.48% after unloading. The radial force of polished stent was 8.32 N. The 3D printed vascular stent can remove the surface powder through electrolytic polishing to improve the surface quality, and show good dilatation performance and radial support performance, which provides a reference for the practical application of 3D printed vascular stent.

The clinical utilization of B-type ultrasonic diagnosis instrument in measuring sebum thickness / 肠外与肠内营养

Objectives:B type ultrasonic diagnosis instrument is used to measure the sebum thickness and the relevance vs evaluated with sebum thickness calipers in sebum thickness determination. Methods:The study included 219 healthy adult persons and 11 cases of corpse dead of non disease reason for less than 10 hours.The measurements of sebum thickness were made by B type ultrasonic diagnosis instrument and sebum thickness calipers respectively. Results:The measurement results of two different methods were not significantly different. Conclusions:It is feasible to use B type ultrasonic diagnosis instrument for the measurement of the sebum thickness in clinic.