Summary

I was advised to raise my legs while in bed by my doctor due to having oedma in both legs.
This will raise your legs by 194mm (7.5"). The Part is 250x144x258mm.
The diameter of the recess to fit your calf is 128mm (5"). If you need to scale this to fit your printer then i would suggest only reducing the Y and Z dimensions. Other wise it may cut off the blood flow if too small.

The recess i lined with felt pads so that any excess water is not trapped. My mattress is quite stiff but for softer ones a board underneath may be helpful.
The two halves are bolted together using M6 x 30mm bolts.

I printed the first half using cura with the default settings for support. The print was about 175 hours and with about two thirds of the filament used (1.6kg) was for support.

The support was a lot more than needed so on the second half i then changed the infill settings to 10% and tree type support. This worked well and saved about 90 hours of printing time. Filament used was less than 1kg.