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Preparing for a talk. I read up more about the applications of origami.  One device that is origami-based is the medical stent.  In June 2003, Zhong You and Kaori Kuribayashi presented a paper entitled A Novel Origami Stent(1).  Stents are tubes that are inserted into the body e.g. in the gastrointestinal tract or blood vessel to dilate it and/or provide support.

The requirement is for a stent to be small so that it is easier to insert, and capable of expanding to a bigger diameter at the chosen site.  Expanding stents were previously made from metal wire mesh covering a frame.  The researchers were looking for a device made from one integrated unit.  They hit upon the idea of using origami to design this.  The final design was presented at the 2003 Summer Bioengineering Conference.  This has now been made into a medical product.  A picture of a stent before and after it is deployed is shown on the left.

Photo credit: World-Science.net

The origami design of the stent is based on a grid of water-bombs.  The basic pattern is shown below:

Crease Pattern for Stent

If you pre-crease the waterbomb-based crease pattern and collapse it, the result is an origami stent.  (The origami stent is cylindrical while the medical stent is helical in design, but the basic idea is the same).  The photos below show the stent in the collapsed and in the (partially) expanded form.  (Note : I used a 8 x 16 grid for the model, the pattern above is a 3 x 4 grid).


The Origami Stent


The Origami Stent (partially expanded)

I was rather intrigued that this pattern is basically the same as that for the Origami Magic Ball, which I wrote about in my previous post.  You can see this from the pictures below, which showed the Origami Magic Ball before and after expansion.


Collapsed Origami Magic Ball


The Origami Magic Ball


Happy folding!

(1)  Zhong You and Kaori Kuribayashi “A Novel Origami Stent” 2003 Summer Bioengineering Conference