The four stages of development: a historical prospective of external counterpulsation

There are four stages in medical device development. The beginning starts with some new understanding of physiological concepts which evolve into the formation of an innovative idea. The second stage is the technical development tphase, from idea to the development of a design to technical reality. At this stage, capital funding and patent applications for the development are necessary but they are not considered here. The third stage is experimental and clinical studies, a data gathering phase to provide evidence of safety and effectiveness of the applications of the device. The final stage is society adaptation and acceptance. These four stages do not occur in series but constantly interact and feedback on each other, evolving on their way to maturity.