Human-centered usability evaluation tools for medical software

Nowadays, healthcare increasingly relies on medical equipment: from being a selection criterion when hospitals purchase new equipment, to improving patient safety through design, usability has become a central factor in the medical device market. Usability engineering tackles the open conversation on the consequence of a human error in healthcare and kickstarted a new way of improving patient safety through user-centered design. Human factor engineering’s role is to investigate what caused the user-error, and the usability engineering’s role is to provide a design solution to minimize its occurrence. To eliminate potential harm is unrealistic, but by factoring in the human element within the design process, the manufacturer can mitigate use-related risk. While regulators and manufacturers vastly accept the need for the usability evaluation, a common approach for usability to medical devices is not available at the moment. The usability evaluation methods are reported in standard IEC 62366 as well as in other Regulatory Standards; however, the discrimination on which evaluation technique to adopt and how these methods can be modified is strictly dependent on the product’s characteristic and the human and technical resources of the usability evaluation team. This master’s thesis objectives were to investigate which methods supported best the usability evaluation for medical device software and how to ensure that said methods can provide a benefit in terms of risk identification and minimization. Consequently, this work offers an operative proposal on how to conduct the usability engineering process in a multiple case study which includes various software as medical device (SaMD) usability procedure as the case. The first case study comprises a large family of SaMD; these were evaluated to assess their usability. In contrast, for the second software, the usability evaluation followed the design and development process, usability was considered a valuable input to guide the design process. The research analysis includes state of the art usability engineering methods and a review on the usability references in Regulatory Standards. However, the peculiar feature of the research is to investigate the use of human factors engineering in the usability evaluation. Besides, the work illustrates the cognitive process behind the interaction between the user and the user’s interface during the preliminary work as during the usability test. This approach was presented to provide an operative understanding of how it may inform the choices among renown usability evaluation methods and deliver further improvements to the manufacturer company. The research method and the inclusion of the company experience led to the definition of a protocol composed of different propositions. The approach proved success during the adoption for the development management and the validation of the user interface, ensuring the identification of use-related risk and critical tasks that might have led to an adverse event. Therefore, such an approach can be effectively applied to evaluate the usability of different SaMDs in every step of the life cycle of the device.