I have a little training on repair of medical equipment. An a lot of experience on small computer systems.
It would be very hard to get FDA approval even for a remote monitor device if it was involved in life support. Desktop computers in medicine have to be keep out of the life support loop. The can be used for billing, research and administrative yaks. No responsible manufacture would certified a product that they can not 100% control. That is what rules out the PC for life support. The PC is just too open.
I mentioned earlier the PULSE OXIMETER.
This device is made by a number of companies, is self contained, has visual and audible alarms, very portable, can be wired to an external alarm and can do simple telemetry. And fully complies with FDA rules. Other countries may have similar rules about using equipment that has been certified.
Your project must be limited to an experiment, but must not be used for critical things. A failure of the system could endanger the life of a patient.
The links posted by Soybean are good.