Along this line of thinking, if we knew exactly what was happening in the brain during sleep, could we speed up the process with mechanical/chemical means? Could we turn off brain functions to shrink the cells (or co-opt the existing sleep process and do this after one has fallen asleep), do the cleaning process (faster, while keeping the same effect) then wake up for maybe 30 minutes total of "sleep" a day? I personally don't think it's possible, at least for another century or so, because it's attempting to hack a body function and do it better (faster) than the body naturally does it (a dialysis machine is a poor substitute for a real kidney). Is there any example of a biomedical tech advancement where some part or mechanism in our body was augmented/replaced with something works better than the original?