Star Trek versus my imagination

What if we could read human cells, or any cell for that matter, in real-time and check for their metabolism, physiology, motion, differentiation, development... What am I missing?

I'm not talking about a full body vital signals reader like Scanadu. I'm talking about something (still inside my imagination, by the way) which would have the resolution to allow us to distinguish each type of cell or tissue and give us an image of it, among other parameters - live and in color.

Molecular Biometrics Intro - by BK Design

Much more than a simple light microscope which already does part of the job. Who would want to carry a light microscope in their pocket anyway? It's not sexy enough. And I want it to see much more that just my skin cells or my hair. I don't want it to be physically invasive but I want to see how my lungs take up oxygen (or smog), or see stem cells from my bone marrow differentiating into other cells elsewhere.

I think not even Star Trek Dr. McCoy's tricorder gives me what I imagine! I don't just want to track blood pressure or run an electrocardiogram - I want to see the blood flow, pause it, go backwards and see glucose being consumed and transformed by any cell - in slow motion! I want to see a "normal" cell and a tumorous cell side-by-side in action. I want to see if one "eats" one or two glucose molecules at the same time as the other.

Oh well, I guess Star Trek's tricorder is history... it doesn't fulfil my wishes for the future, created by my present imagination.