Application of usability testing to the development of medical equipment. Usability testing of a frequently used infusion pump and a new user interface for an infusion pump developed with a Human Factors approach

In medical care, the infusion pump is one of the most common pieces of technical equipment often involved in incidents due to handling. In order to improve usability and reduce errors, a new user interface for an infusion pump has been designed based on an analysis of observations, interviews, heuristic evaluation, reported incidents and theory about mental capacity and human error. The purpose of this study was to determine whether or not the new interface would reduce the number of handling-errors and problems, and how it could be further improved. For this purpose usability tests were performed by 18 nurses from three different hospital wards. The results showed that the number of handling problems were reduced for the new interface compared to the existing interface, but the number of errors was still high. The tests indicated a need to further improve the new interface in terms of spring-loaded modes where the users are only in the desired mode as long as they actively hold down a button. In identifying user requirements for medical equipment it was found important to use different data collection techniques. In this study it was further found that the nature of the information from the different user groups in usability tests can differ widely. The experienced users had the competence and self-confidence to be critical and suggest improvements based on their practical experience. Whereas the novice users were important since they encountered most of the serious problems and made the most mistakes. There is a need to develop viable techniques to enable manufacturers of medical equipment and hospital personnel to critically specify and evaluate usability qualities when formulating user requirements for new medical equipment.