For a couple of years, I've taken my resting heart rate immediately after waking up. I go low tech and just take it at my radial artery over 15s, multiplying by 4 to get BPM.

It just occurred to me, after talking with a friend, that there are some really basic and pretty affordable fingertip oximeters available. Do any of you use one for this purpose? Any suggestions?

Not sure why I would switch, exactly, besides more accuracy and a bored desire.