This is a great UI sprite, but how am I supposed to use the health bars?
Not entirely clear what you're asking for.
### I assume it's a technical question here:
Well, it very much depends on the engine/framework/libraries/others you use to create your game. I imagine you'll have to slice/cut/mark-regions-of the bitmap and render the elements of the health bar you want to see in the place you want to have them.
Rendering a couple of fragments of a bitmap must be quite easy in any setup - you'll handle this!
### I assume it's a ux question here:
Segmented health bars are easier to read for the player I guess but the values have to be in small ranges + the with might change during the gameplay (or with different characters). The continuous ones can be always the same width (hence more consistent visually) but the player might not know instantly if particular value is "a lot" or "very little" in particular instance.
Either case, when the red bar shrinks to nothing then the character is dead (usually).
This is actually a complicated topic and there is no best answer here (although there are plenty bad/good ones). Let know if you figure out something unique!
### In any case: