I'm looking for a piece of equipment and I'm not sure what to search for.

This all came about because I need to get something where I can lay on my stomach, back, or side with my head pointing down hill for 30 min several times a day (treatment after lithotripsy for kidney stones). My stones get blasted Oct 27, so I have a bit of time to find something. I was searching incline boards, but have only come up with the ones used to stretch calf muscles or leg press machines which puts my butt at the wrong end of the incline 🤣.

When I was doing rehab and strength training for a subluxing patella quite a few years ago, the place (out of business now) had a piece of equipment that had an adjustable incline but it also had a gliding backboard (or it could be locked stationary) so you would stand on the tilted base and do leg exercises using your own body weight for resistance (I guess kind of like inclined squats or calf raises). I have no idea of the brand or what it was called, but I thought that would fit the bill for my kidney stone recovery PLUS I could use it for other exercises. I always enjoyed the part of PT where I used that equipment. Since I thought it was fun, I saw knee strength and stability increase rapidly.

Just thought someone here might have used something like that or at least have an idea of another term to use in a search.

Thanks in advance for any ideas!