Impact of UI design patterns on cognitive load, perceived usability, and confidence to use critical healthcare devices

Ventilators are critical medical devices that treat seriously ill patients in intensive care units (ICUs). Literature indicates that approximately 50% of adverse ventilator events are caused by user errors. A clear and well-organised interface can reduce cognitive complexity, improve usability perception, help prevent errors, and ultimately build user confidence. This study explores the categorical role of design elements such as aesthetic graphics, font, color, gestalt, transition, hierarchy, control, interactivity, and animation in enhancing the perception of system usability. An experimental prototype of the next-generation intelligent ICU ventilator was developed with minor variations using a participatory design approach to conduct experimentation. A questionnaire was administered to 535 healthcare practitioners (i.e. doctors, nurses, medical students, & caregivers) to gather feedback and corroborate the proposed research model and hypotheses. Data were analysed using the partial least squares method. The effects of font, color, hierarchy, and control on both cognitive load (mental workload) and perceived usability are found to be significant. Moreover, aesthetic graphics, transitions, and animations are negatively associated with cognitive load, while Gestalt principles and interactivity are linked to perceived usability. The results are unique and critically important for patient safety, as they discuss the key design elements most crucial in developing the interface of healthcare systems that are easy to understand and effective to use. This helps prevent adverse events or errors from arising during the operation of critical devices.