How to stop hands from falling asleep?

Increasing your relative blood volume or the ability of you heart to pump will help your hands. More fluid intake, maybe meds, definitely more salt

YOSUDA Under Desk Bike Pedal... https://www.amazon.com/dp/B07ZFBBD6J?ref=ppx_pop_mob_ap_share I highly recommend this. I got it for legs as i put it up on my couch and use it reclining. But i also had breast cancer and use it for my arms (post surgery). Lots of resistence settings, very quiet, etc.

Stress ball squeezing

Lack of circulation. I move around alot. Even when relaxing. No blood pooling that way.