Hey Dan,
I liked the way you presented the problem, very clear and easy to grasp. The sketch pages are a let down though, the sketches are really hard to see, some are super small, some really faded, and the overall organization feels too sparse.
Take a look at some nicely composed sketch pages, Carl Liu’s stuff is great, you can tell that there is some thought put into how he’s arranged the page, variation in size for hierarchy, good use of space, nice linework etc.
The final model is ok for a hand made mock up but if you have the time/desire I’d put it in CAD and do some final renderings for your portfolio, maybe even 3D print it from Shapeways to do a refined prototype if you’re feeling adventurous?
The overall aesthetic feels a little toy like to me, part of it might be the resolution of the mockup, putting it in CAD might help to tighten it up and make it look more refined. Might be nice to have a final shot of it on an EMT’s shirt or in use? Good luck!