Design and Characterization of Micro-grooving on Flow Diverting Stent

Seth Harriet, Zack Maggard, Dr. Mohammad Hossan, and Dr. Mohammad Hossan, University of Central Oklahoma Biomedical Engineering Department, University of Central Oklahoma, 100 North University Drive, Edmond Oklahoma, 73034.

Flow diverting stents (FDS) have become one of the most promising endovascular treatment of brain aneurysms. A FDS implant regulates blood flows and supports vascular walls to dissolve aneurysms and remodel vascular networks. However, recent studies show that micro-motion and dislodging of FDS are responsible for late thrombosis, in-stent stenosis and other serious health issues. This paper presents the analysis and characterization of micro-grooving on nitinol FDSs that can improve the stability, mechanical adhesion and endothelization of FDSs. Using two CAD software in unison, a 3D model of the FDS and grooving was developed. FDSs with 3 um, 6 um and 12 um depth micro-grooved patterns were fabricated based on the CAD model and the use of a precision laser with modified rotational components and microcontroller code. A vibrating polishing machine was designed and developed to polish the FDSs using 3D printed parts and mechanical shop tools. The performance of the vibrating polishing machine was evaluated with crushed walnut shell and micro-glass beads media at various polishing times. The quality of the FDS surface polish was evaluated using SEM images. The groove profiles and depths were examined using a 3D profilometer and flat nitinol samples. A mathematical correlation was developed from the grooved flat nitinol samples to determine the depth and profile of the micro-grooving on the FDSs. The results demonstrated that various micro-grooved patterns were precise on the FDS and without micro-cracks using the laser machine. The results also show that the vibrating polish machine can successfully remove impurities and debris from the laser machined micro-grooved FDSs. The crushed walnut shell was found to be the more effective media. The micro grooving and testing of the FDS is a step in the direction to find a more perfect medical procedure to combat the brain aneurysm.

Additional Abstract Information

Presenter: Seth Harriet

Institution: University of Central Oklahoma

Type: Poster

Subject: Biological & Chemical Engineering

Status: Approved

Time and Location

Session: Poster 2
Date/Time: Mon 3:00pm-4:00pm
Session Number: 2544