One of the key challenges of medicine is detection. When the homeostatic network of biological systems drift from their steady state towards disease state we'd like to know about these changes as early as possible. Instead of designing lots of expensive nanobots that need power, communication mechanisms, etc., couldn't we simply leverage the computing and communication mechanisms that already exists within the machinery? We're loaded with feedback loops, pulse generating networks and chemical signaling. It would seem that through synthetic biology we could engineer a few key gene inserts whose product act as biomarkers that monitor various protein concentrations and drop messenger proteins into the bloodstream. Or even better, there are numerous ancestral genes and signaling cascades that are simply lying around in a defunct state. Rather than engineering a new product and cascade, it might be easier to find a harmless one and reactivate it to eliminate the need to solve the challenge of getting the marker outside the cells. Perhaps a device strategically placed in the toilet bowl could measure these (along with the already natural markers of course).
Perhaps an idea to revisit after we cure aging
