To Boldly Go Where Fitness Trackers Can't

Even the term we use for talking about analyzing the body's data—"quantified self"—suggests a solipsism to be avoided. We care as much about the health of those around us as we do our own. (Sometimes, to our detriment, we care a bit more—caretakers famously neglect their own health.) To realize its ambitions, I think Scanadu needs to do more than build a tricorder. It needs to connect the Scout to other apps and devices that track our exercise, nutrition and sleep. From there, it might begin to offer ideas of things to fix. But the notion that we can find out that something's wrong with us by holding a gadget against our heads is itself something out of science fiction.

Scanadu's Walter De Brouwer tracks my vital signs on his smartphone.