A Canadian team calling themselves Brand & Grotesque have set up a Kickstarter page for "Blood Sport", an arduino-controlled rig that actively draws blood from a player when they take damage in a videogame. With a goal of 250,000 Canadian Dollars (which is still a lot, even when converted to real money) their goal is to make rigs that can be set up at gaming events to raise awareness for donation drives.
This isn't actually a medical device, the regulations for donating blood are reassuringly strict, but as an interactive art/commentary/thing? It's still pretty wicked. Watch the video to see their pitch.
All that's left is to incorporate it into an Oculus Rift and we'll have an awesome immersive experience/deathtrap from the Saw movies.