Oxygen helmet for stroke

This should easily  be able to be repurposed for stroke, I'm sure with a good neck seal you could simulate HBOT, although I have no idea why you would want to.
A failed HBOT trial here
Peter Levine talking about problems of HBOT here:

Stroke and Hyperbaric Oxygen Therapy

Or maybe mimic high altitude which has been proven to be useful for  angiogenesis. Training the Brain to Survive Stroke
From a Great Disorder blog;
http://greatdisorder.blogspot.com/2010/03/focus-focus.html