This made me think of Calico/Google trying to develop early cancer detection systems. If I recall correctly, they wanted you to swallow something that would be wandering in the bloodstream, ready to attach to loose cancer cells. That combo could then theoretically be measured by a wristband of sorts that we would wear around.

I remember seeing that demo 8 or 9 years ago. Yet here we are, still waiting for the pancreas to start hurting, when it's obviously too late to do anything about it. If only we had good incentives around preventive care...