Medical Beds are available later on in the Tech Tree (Tech Level 4), which requires a few prerequisites before becoming available.

You'll need the following to unlock the research for Medical Beds:

Beds, Skeleton Repair Beds*, Medicine, Advanced Medicine, Splints, Advanced Splints

*You might need the following to unlock Skeleton Repair Beds (?):

Prototype Skeleton Bed (Tech 2, Electric)

Bed, Light Wind Generator Theory, Basic Exterior Lighting

It should appear under the "Core" tab once those other research projects are completed. I don't remember the exact stats for the bed, but it's somewhat similar to a Skeleton Repair Bed in terms of healing rate and such.

I do wish there was a way to show routes for research, like in RimWorld for example, but unfortunately it's not possible currently. Everything somewhat follows a logical path to unlock though, for the most part lol