The usability of ventilator maintenance user interface: A comparative evaluation of user task performance, workload, and user experience

Poor usability designed of ventilator user interface can easily lead to human error. In this study, we evaluated the usability design of ventilator maintenance user interface and identified problems related to the usability of user interface that could easily cause human error. Sixteen respiratory therapists participated in this usability study. The usability of the ventilator maintenance user interface was evaluated by participants' task performance (task completion time, task error rate), physiological workload (eye-fixation duration) and perceived workload (NASA-TLX), and user experience (questionnaire). For task performance, task completion time and task error rate showed significant differences. For task completion time, significant difference was found when conducting ventilator self-test (p < 0.001), replace the breathing circuit (p = 0.047), and check battery status (p = 0.005). For task error rate, the three ventilators showed significant difference (p = 0.012), and the Serov I showed a significantly higher task error rate than the Boaray 5000D (p = 0.031). For workload, the Serov I was associated with higher physiological and perceived workloads than other ventilators (p < 0.05). For user experience, the Boaray 5000D received better scores among the ventilators in terms of ease to maintain, friendly to maintain, and willingness to use (p < 0.05, respectively). Our study adds available literature for usability evaluation of ventilator maintenance user interface. The results indicate that the maintenance user interface of the Boaray 5000D performed better than the other two tested ventilators. Moreover, the study results also proved that eye-fixation duration can be a reliable tool for evaluating the usability of ventilator user interface.

Impact of Design on Medical Device Safety

The growing number of emerging medical technologies and sophistication of modern medical devices (MDs) that improve both survival and quality of life indexes are often challenged by alarming cases of vigilance data cover-up and lack of sufficient pre- and post-authorization controls. Combining Quality with Risk Management processes and implementing them as early as possible in the design of MDs has proven to be an effective strategy to minimize residual risk. This article aims to discuss how the design of MDs interacts with their safety profile and how this dipole of intended performance and safety may be supported by Human Factors Engineering (HFE) throughout the Total Product Life-Cycle (TPLC) of an MD in order to capitalize on medical technologies without exposing users and patients to unnecessary risks.

Usability Study of Two Common Defibrillators Reveals Hazards

STUDY OBJECTIVE

This usability study evaluates the user interface of 2 common monitor-defibrillators, the Lifepak10 and Lifepak12, to identify use-related hazards.

METHODS

Fourteen paramedics familiar with both devices completed 4 EMS simulator scenarios using each device. The scenarios involved "quick look" and monitoring, defibrillation, synchronized cardioversion, and replacing paper. Qualitative and quantitative data were collected, including both participant self-evaluation (scored 1 to 9) and expert observer evaluation (scored 0 to 4).

RESULTS

Participant ratings demonstrated that for performing a quick look, the Lifepak10 was easier to use (mean 8.0 versus 7.1), and for synchronized cardioversion the Lifepak12 was easier (mean 6.7 versus 5.3). Participants performed better on the Lifepak12 than the Lifepak10 for synchronized cardioversion (mean 3.1 versus 1.6) and replacing paper (mean 3.0 versus 2.1). One participant did not complete the final questionnaire. Of the remaining 13, 11 (85%) participants preferred the Lifepak12 for use on a regular basis. Eight (62%) paramedics thought that the Lifepak12 would be more effective in an emergency; 9 (69%) believed that the Lifepak10 is quicker to learn. Paramedics reported difficulty using the devices with gloves and confusion in "sync" mode. Of note, 50% of participants inadvertently delivered an unsynchronized countershock for supraventricular tachycardia.

CONCLUSION

Although the Lifepak10 is easier to learn, the Lifepak12 is perceived as easier to use and more effective in emergencies. The high failure rate in synchronized cardioversion indicates a need to reevaluate the user interface design for this function. Limitations of this study include the use of simulation.