Why hasn't anyone even tried to make a pod lifesupport system?

I just realised no matter how we die it's always Hypoxia. Your die naturally? Heart stopped - no oxygen. You die brutally, and unnaturally? Blood loss - no oxygen.

This made me wonder why let people die naturally if we go through so much to keep em alive from disease etc?

If you had an iron lung or a pod that pumped your blood, oxygenated it, cleaned it of toxins you could just exist. Organ failure wouldn't be an issue except for your brain. We're headed to a future of implants, Al & robotics. You could just exist in that pod, and be plugged into the net with all your senses, hell you could jack into a robot body, and live a full life remotely. Yet no one has even attempted this - why?

I know it's more complicated than the concept I came up with, but still. No ones tried it yet we came up with chemo, the iron lung, and pacemakers, gene therapy, but no news of even an ATTEMPT!