The user needs you have defined should be the primary source for your design inputs. When a team is involved, you get everyone’s experience and opinions, which will make the effort stronger. Besides user needs and the team, there are several more sources you should consider while defining design inputs: Industry standards, Regulations, Previous projects or products, Competitor products, End users and Prototypes. You need to consider all aspects of the medical device you are designing and ensure that you have defined all design inputs. You should capture everything, all criteria about your product, what’s important, how the device should perform, and so on.