This post was originally produced for Forbes. Dean Kamen doesn’t waste his time on problems that don’t need to be solved. Early in his career he invented the first infusion pump for delivering medicine. The company he built around it has made him wealthy and he’s spent the rest of his career working–rather successfully–to repeat the success. Though he may be most well known for the invention of the Segway, his more recent work on the Stirling Engine power generator and the Slingshot water purification system hold promise for the developing world.