How can I "distance tracker" that runs a code I put?

So, you may be confused by the title but to be exact.. I'm trying to find a way to create a script which can detect a physical object in it's detector. (in-studs)

What I'm kinda looking for

•Updated continuously, with out while true do (unless it's a only option)

•Not using a part with a touched event or something similar.

What I've tried So, I used workspace.FindPartInRegion3 which is good but, not what exactly I'm looking for since I'm trying to use a loop.

NOTE This may be a request but I've been looking through stuff. I'm obviously not going to just wait until I get an response so that is a way for me to understand some stuff to help me get this code in. Thanks for your time.