Waking up with numb hands, needs suggestions/recommendations

It's a few months that I started having this situation, I wake up at night and one of my hands is numb (just once it happened both at the same time), it's mostly the left, rarely the right. In particular it's the two fingers starting from the pinkie, plus the lower part of that side. For what I understood they are related to one of the two main nerves that come into the hand.

I had a few visits to the doctor. The main outcome was that I was suggested to wear a splint at night to keep the elbow straight, and it fact it worked, when I use that I don't get anything. The hypothesis from the doctor was that the nerve is being compressed in the elbow area when I bend my arm at night. The other thing I did was a nerve conducting test of the arms nerves, I still have to see the detailed outcome but from a first glance it seems all good. The problem with the splint is that as soon as I stop using it the problem comes back (less often that the original period, but still).

The other thing I was suggested from a friend (a doctor as well) was that it could come from a position I sleep at night, but not necessarily the bended arm. So the suggestion was to record myself at night and see if a specific position is triggering the situation.

My questions are: - did anyone ever had this problem and can get me some advice? (out of curiosity, I'd obviously listen to the doctor first) - do you have any recommendations for a camera I could record myself with? I believe it needs to have some sort of night vision