Medical device design for surgeons, nurses and others in the medical professions requires that the designer understand how these specialist populations use the devices that are unique to their specialties. The techniques that doctors and dentists use with specialized injection devices, for instance, is often not obvious to the lay person. It’s essential that direct observational research be done to reveal how medical professionals are accustomed to using similar devices to the one you are developing. Long standing historical precedence with form factor and device configuration can cause practitioners to develop ingrained habits that could lead them to use a newly designed device in a way that a lay person would view as unorthodox. We have seen this many times. In medical device design, the admonition, “know your user” cannot be understated.