There used to be a gizmo that took a reading off the baby's forehead, that was inaccurate also, but gave you a reference pt.
The goal here would be to reduce the number of times the baby got stuck. So, what I might do is to place the monitor on, get a reading, then warm the kid's foot, and send a sample to the lab. Now you know how far apart they are. If the moniter goes up, presumably the lab results would rise also. You could adjust the baby's therapy accordingly.
You would still have to get a real lab result once or twice a day, and I don't know how often you do it now, but that gives you an idea of how you can use this monitor.
When you get a lab, be sure to warm the heel, it really does help. Either use a heel warmer device, or a diaper you've run under WARM, not hot water. You can check the temp of the diaper with a thermometer if you have asbestos hands like me. I like the diaper to be about 100F.
Also, you can use neosporin ointment in a very THIN
film over the heel so the blood will "bead up", and you won't have it wasted all over everything but the container you're trying to collect it in!
There is a neonatologist I work with who can often "call" the bili level w/in 0.2 of the lab value!! I can always send him over if you want!!