> For all we know, Siemens already has a smaller, cheaper device that uses only a drop of blood, yet no reason to sell it until they get some competition. Do y

> For all we know, Siemens already has a smaller, cheaper device that uses only a drop of blood, yet no reason to sell it until they get some competition. Do you have a source for this? As far as I remember past discussions on HN about Theranos, testing on small samples is notoriously difficult. As an experimental physicist, this seems plausible to me: Say 5% error margin on your result is required. This leaves a lot more leeway for dimensional errors (of the sampling chamber) compared to a few µl. Not to speak of introducing external impurities (or those induced by the sampling as mentioned by the article). I am pretty sure Siemens has lots of incentive to err on the safe side. If we really like to disrupt this industry, it would be nicer to be able to make these tests in-vivo, in my opinion.