Usability Study of the User-Interface of Intensive Care Ventilators Based on User Test and Eye-Tracking Signals
Mingyin Jiang, Shenglin Liu, Qingmin Feng, Jiaqi Gao, Qiang Zhang
(Department of Medical Engineering, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland))
Med Sci Monit 2018; 24:6617-6629
The aim of this study was to evaluate the ergonomics of the user-interface for 3 intensive care ventilators, and identify usability problems leading to user errors.
MATERIAL AND METHODS: Sixteen respiratory therapists were recruited to perform 6 specific user-interface operational tasks on ventilators. Data (task completion time, pupil diameter, average slope of pupil diameter change, and subjective evaluation) were collected through objective measurement, questionnaires, and an eye-tracking instrument.
RESULTS: For task completion time, there were significant differences among ventilators in recognition tasks of ventilator mode and settings (P<0.05), modification of ventilator modes and recognizing (P<0.05) and changing alarm settings (P<0.05). A mean of 15±2 task failures was observed for each ventilator. For the change of pupil diameter, a significant difference was observed between ventilators (except task 2, P<0.05). For average slope of pupil diameter change, a significant difference was also observed between ventilators (except task 2, P<0.05). The Servo I showed a better correlation between task completion time and pupil diameter change. The subjective evaluation results were clear: Evital 4 received worst scores in terms of friendliness of user-interface, information display and safety (respectively, P<0.05).
CONCLUSIONS: The present study provided valuable evidence to indicate the ergonomic of ventilators now used in China. With the result of this study, we can infer that the Evital 4 were poorly ergonomic designed. Furthermore, the study also demonstrated that eye-tracking can be a promising tool to evaluate the ergonomics of the user-interface.
Keywords: Critical Care, Equipment Design, Equipment Safety, Eye Movements, User-Computer Interface, Ventilators, Mechanical