Hi,
Well, checking for dehydration, Alcohol Sensor, and what else you want? Are you talking about a rebreather unit or a rebreather cabin with tens of sensors now? or maybe a personal sub with a waitress?
I think the idea of the Data Mask is actually fantastic in the PPO2 would be monitored within the mask then CCR diving rule #1 won't be an issue anymore as the user will be able to literally to know his/her PPO2 all the time (As every second). I actually think the idea would be excellent to add up additional wireless display instead of simple HUDs, so users can have exaact duplications of what the original handsets are showing OR just to copy the main features that divers need to know regarding decompression stops, tanks pressure, depth, PPO2, etc. But since that it's available yet in an integrated wireless package yet then I think Data Mask with the current HUDs is the closest to that. I appreciate the mask especially when diving in 2 degrees dark water with Remaining Air Time feature.
Best Regards. Wael