As part of the build up to a medical expedition to climb Everest in 2007, the Xtreme Everest Team travelled to Tibet to attempt to climb Cho Oyu (8201m) the sixth highest mountain in the world.

One of the major areas of research interest for both expeditions is the blood supply to the brain (cerebral perfusion) since we know that can be seriously affected at high altitude. We were looking for a robust portable transcranial Doppler system that would would be simple to use in an extreme environment.

SonoSite kindly loaned us one of their state of the art portable MicroMaxxR machines, which performed outstandingly at altitudes as high as 6400m and in temperatures as low as -20C (the most extreme environment that TCD examinations have so far been attempted). We hope to gain better insight into why people who are short of oxygen, either up a mountain or in intensive care become sick.

More images related to SonoSite: