Some one in a thread on this board talks briefly about making a catastrophic oil loss indictor possibly that also shuts down the engine in such a case. I just tried a quick search and did not find it but I am pretty sure the key words are catastrophic oil loss if you can find the thread you could ask him how he did it. He did say it was quite difficult though. I just looked some more using those key words and found a few posts including one about a commercially available unit Low Oil Pressure Alarm
Dave S