A stent is a medical device used to reopen narrowed arteries. The vast majority of stents are balloon-expandable, which means that the metal structure is deployed by inflating a balloon, located inside the stent. Figure 6.7 shows an example of such a stent prior to expansion (balloon not shown). The 3D surface is obtained by micro CT and consists of triangles.
The structure of such a device can be quite complex and difficult to analyse. The same functions pyFormex offers for creating geometries can also be employed to investigate triangulated meshes. A simple unroll operation of the stent gives a much better overview of the complete geometrical structure and allows easier analysis (see figure 6.8).
F = F.toCylindrical().scale([1.,2*radius*pi/360,1.])
This unrolled geometry can then be used for further investigations. An important property of such a stent is the circumference of a single stent cell. The clip()
method can be used to isolate a single stent cell. In order to obtain a line describing the stent cell, the function intersectionLinesWithPlane()
has been used. The result can be seen in figure 6.9.
Finally, the length()
function returns the circumference of the cell, which is 9.19 mm.