MeD UD – A Process Reference Model for Usability Design in Medical Devices

Abstract

Abstract.A critical component to the success of software systems is the incorporation of the end user. Ensuring that the end user can use the system effectively and efficiently is an important consideration. Failure to do this can lead to user error which in turn can have serious or even fatal consequences. To address this issue in the medical domain, where the risk to patient and user safety is quite high, a number of standards and guidance documents promote the use of Human Factors and Usability Engineering techniques during the development of devices. In this paper we introduce MeD UD (Medical Device Usability Design) -A Process Reference Model (PRM) for evaluating usability engineering in the medical device domain. Through a process assessment utilising the MeD UD PRM, medical device organisations can improve their usability design processes to achieve more usable products, reduce the risks associated with user errors and efficiently meet the medical device regulatory requirements. Keywords IntroductionThe development of technology in recent years has allowed for medical devices to provide more effective and efficient patient care. These results can be attributed, in part, to the increasing role of software within medical devices. Through the use of software, complex configuration changes can be implemented easily. In 2006, it was noted that software was now incorporated into over half of the medical devices for sale on the U.S. market [1]. A side effect of the increased complexity of medical devices is the increased chance of human-error. Errors, slips and lapses can occur in every aspect of human activity. When these mistakes occur with medical devices the results can be fatal. In 2007, Ms. Myra Jean Garman took her own life to escape the pain she suffered as a result of the misapplication of a medical device. Ms. Garman, who was suffering from breast cancer, was left in severe pain after she was given twice the recommended dose of radioactive seeds on five separate occasions. The state regulators attributed the over radiation to a mistake on behalf of a physicist who had entered an incorrect magnification factor into the treatment planning computer.[2] Ms. Garman is unfortunately not an isolated incident. In New Jersey 36 cancer patients were over-radiated and a further 20 received substandard treatment due to human-error during the application of a medical device [2].Errors like these can be reduced through the use of usability engineering. Usability engineering is the "application of knowledge about human behaviour, abilities, limitations, and other characteristics related to the design of tools, devices, systems, tasks, jobs, and environments to achieve adequate usability" [3]. The incorporation of human aspects into the design process enables designers to develop interfaces in accordance with the users' expectations and needs which can improve the overall user experience and reduce the likelihood of human error.Software Process Improvement (SPI) frameworks such as SPICE [4] or CMMI [5] allow organisa...