Medical advances depend on technological advances. In practice, in many clinical situations, it is often possible to improve work without using such high-tech. Asking what you feel daily is a step toward improvement. To achieve this purpose, it is necessary to feel the inconvenience using your five senses on site. Instead of making a custom-made product based on the idea of one person, we must create a product that many people want and use. You have to figure out how much a product is needed. Think carefully about the features that your product requires. The product should be as simple as possible. There is a manufacturing concept called “BioDesign” advocated by Stanford University. We should be aware of the principles of failure : Fail often, Fail early, and Fail cheap. In this paper, I will present my experience of making medical products through cardiovascular surgery.