I don't know about top three but in the medical field I would have to say the artificial kidney would have to be up there. For people who cannot find a donor m

I don't know about top three but in the medical field I would have to say the artificial kidney would have to be up there. For people who cannot find a donor match, it buys tremendous time to find a living donor. Don't believe the intent is to utilize an artificial kidney permanently but can be used for a lengthy period of time reducing dependence on dialysis, etc. The other in the medical field would have to be the laser scalpels that can do precision deep brain surgery. They have revolutionized brain surgery and allowed removal of tumors previously inaccessible to surgeons. Can't think of anything more valuable than inventions that preserve life.