The term is considered to be synonymous with “human factors engineering” (HFE) and “usability engineering” (UE). HFE is defined as the application of knowledge about human behaviour, abilities, limitations, and other characteristics of medical device users to the design of medical devices including mechanical and software driven user interfaces, systems, task, user documentation and user training to enhance and demonstrate safe and effective use. The advantages of optimising device deign through application of HFE/UE during the development of medical device reduces the need for design modifications and costly updates after market introduction and offers competitive advantages. In addition, when HFE/UE approaches are adopted during the design development process, the overall ease of use and appeal of a MD can be simultaneously enhanced. FDA has specified guidelines to support industry and manufacturers in improving the design of new medical devices to minimise potential use errors and resulting harms, and reduce risks associated with medical device use.