The testing to show "substantial equivalence" are not generally trivial. The "original" device needs to show safety, and effectiveness versus clinical endpoints

The testing to show "substantial equivalence" are not generally trivial. The "original" device needs to show safety, and effectiveness versus clinical endpoints. The follow up devices need to show safety and effectiveness versus appropriate measurements. Some degree of safety testing and/or analysis is generally always required for medical devices, regardless of if its a PMA or 510k. For the specific case of blood glucose monitors, the 510k submission will require testing to show that your monitor is safe, and provides "at least as good" blood glucose monitoring compared to predicate devices. This allows the device manufacturer to avoid having to prove that blood glucose monitoring will improve clinical outcomes for patients with diabetes. Testing to show performance typically requires some degree of real world (ie, with real operators and patients) testing. There are certainly be some cases where this gets abused, but overall I think it's a logical system.