The square peg and the round hole: Murphy's Law and medical device connections

Engineers have long been aware of Murphy's Law: If anything can go wrong, it will. When applied to medical device design, Murphy's Law indicates that if there is a way that a medical device can be set up incorrectly then someday, somewhere it will be set up incorrectly. In the clinical environment the result may be patient injury or death. Despite this received wisdom, clinical engineers continue to encounter examples of medical device design that invite users to do the wrong thing, with potentially harmful results. This paper focuses on electrical and other connectors incorporated into medical device designs. Examples of potential and actual misconnections, from the earliest days of clinical engineering to the present, are presented and discussed.