The medipad is a flat structures that a single humans steps on to regenerate health and stamina over time. So far we only have a very rough concept for it:
Like the other human buildables, it should have glowing elements that can go out when the structure loses power (which is usually done by disabling the addition map). Additionally, it should have means of displaying that it is currently healing someone. Part of this effect can be a particle effect that we place above the pad while it's active, however it would ideally be backed by some glowing or rotating elements on the medipad itself. It is also possible to extend a mesh hidden inside the pad's body via an animation and apply a translucent effect shader on it (this is what the human spawn does when teleporting in a player).
Speaking of the telenode, feel free to let it inspire the art style of the medipad as it has similiar mechanics:
Unlike the telenode which spawns humans in a certain angle the medipad should be symmetric as it can be used from any side; Ideally the medipad would be round as in the sketch above. Also note that the telenode is about twice as high as the medipad should be (you're not supposed to step up on a telenode, just down from it).