A similar device was proposed a while back-- a nanopore DNA sequencing array implanted into the heart that checks all circulating DNA. In context, the authors h

A similar device was proposed a while back-- a nanopore DNA sequencing array implanted into the heart that checks all circulating DNA. In context, the authors had proposed embedding some enzymes in every neuron to record action potentials, neurons would excrete the DNA into the bloodstream, and then you would recover the entire connectome and all the action potential history by DNA sequencing any circulating DNA that makes it to the heart.