If the output is all that is important, this looks like an easy job for an Arduino to handle.
One may need a capacitor to smooth the rise/fall, besides that, how the "patient is doing" can easily be programmed in your Arduino - you can make your custom "death scenario" : from a very excited state, to erratic movement, to flat line, then come back with a few random beats, then flat line again... then ... RIP!
I like a random single/double/triple beats after a random 10's of second pause, you know, to keep the relatives hopeful, then quiet... Just as they begin to count their inheritance, it beats normal again. Grandpa is back... You'll have to wait a bit longer for your Gran Torino after all.