[idealmedtech]

They're not enormously complex from a hardware perspective, but the sensing element is really hard to get right. Interference from a whole host of common drugs (including ibuprofen) can really mess up one's signal. Not to mention the regulatory moat; many medical device startups die on the vine working for regulatory approval, or looking for funding for expensive human trials (which quickly get into the millions or tens of millions for a Phase II/III trial)