Erik Liljegren

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

Abstract 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. Relevance for industry 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.

Setting the Requirements for a User-Friendly Infusion Pump

The infusion pump is a commonly used piece of equipment at the Intensive Care Unit. The pumps often are from different manufacturers and have different handling characteristics. The ICU is a dynamic environment, with periods of calm interrupted by periods of very high activity and mental load. Infusion pumps are often involved in reported incidents. The purpose of this study was to set requirements for a user interface for an infusion pump, using a systematic human factors approach. The method used consisted of field studies at an ICU, a critical evaluation of two pumps presently used at this ICU and an analysis of reported incidents which involved infusion pumps. Both pumps in the evaluation had a number of latent errors. Two types of incidents relating directly to the user interface were found, both of which could be traced back to latent errors. A number of requirements were set with the purpose of reducing the risks of the two types of incidents occurring and reducing the mental load of the user. Using these requirements, a new interface for an existing volumetric pump was designed.

Usability Evaluation of 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 and it is often involved in handling-incidents. In order to improve usability and reduce errors, a new user interface for an infusion pump has been designed with a human factors approach. The purpose of this study was to determine if the new interface could reduce the number of handling-errors and problems, and to find out if the interface needed to be further developed. For this purpose usability tests were performed with nurses at three different hospital wards. The results showed that the number of mode errors and arisen problems were reduced for the new interface compared to the existing interface. However, the usability tests showed that there is still a potential to improve the new interface further. The results also showed that the number of errors was very high when handling these infusion pumps. This is an indication of that this area is important to study further. A conclusion was that usability testing is an important complement when redesigning interfaces with a human factors approach.

Developing User-Friendly Interfaces for Medical Devices

Abstract Usability is an important aspect in medical device design. The purpose of this study was to investigate the use of Enhanced Cognitive Walkthrough (ECW) and Hierarchical Task Analysis with Interaction (HTA-I) in the design of two new user interface concepts for infusion pumps. Usability tests showed that the new concepts had greater usability than another user interface designed with a Human Factors Approach. Using ECW in the existing systems analysis means that more latent errors were found than with CW. HTA-I is a useful tool when defining function structures in the design stage where no physical prototype exists.