Human Factors Evaluation of HeartMate 3 Left Ventricular Assist Device Peripherals: An Eye Tracking Supported Simulation Study.

BACKGROUND: Despite recent design improvements, human factors issues continue to challenge left ventricular assist device (LVAD) therapy. The aim of this study was to evaluate user experience of former non-HeartMate 3 (HM3) LVAD patients post heart transplantation (HTX) and laypersons (LP) with HM3 LVAD peripherals in simulated everyday and emergency scenarios. METHODS: This single center cohort study included untrained HTX and LP. Seven scenarios, including battery exchanges (without alarm, advisory alarm, dim light, consolidated bag), change of power supply, driveline dis-/reconnection and controller exchange were simulated. Subjects' gaze behavior was recorded using eye tracking technology. Success rate, pump-off-time, duration to success (DTS), percental fixation duration per areas of interest and post-scenario-survey results were defined as outcome measures. RESULTS: Thirty subjects completed 210 scenarios, initially solving 82.4% (HTX vs. LP, p = 1.00). Changing power supply revealed highest complexity (DTS = 251 ± 93s, p = 0.76): 26.7% succeeded at first attempt (p = 0.68), 56.7% at second attempt, with significantly more LP failing (p = 0.04), resulting in 10 hazards from driveline disconnections (pump-off-time 2-118s, p = 0.25). Comparison on initial success showed differences in fixation durations for seven areas of interest (p < 0.037). Decreasing DTS during battery exchanges (p < 0.001) indicate high learnability. Exchanging batteries within the bag took longer (median DTS = 75.0 (IQR = 45.0)s, p = 0.09), especially in elderly subjects (r = 0.61, p < 0.001). Subjects with less initial success were more afraid of making mistakes (p = 0.048). CONCLUSION: This eye tracking based human factors study provided insights into user experiences in handling HM3 peripherals. It highlights unintuitive and hazardous characteristics, providing guidance for future user-centered design of LVAD wearables.

Real-Time Intubation and Ventilation Feedback: A Randomized Controlled Simulation Study.

BACKGROUNDS: This study aimed to determine the best educational application of a respiratory function monitor and a video laryngoscope. METHODS: This study was a randomized controlled simulation-based trial, including 167 medical students. Participants had to execute ventilation and intubation maneuvers on a newborn manikin. Participants were randomized into 3 groups. In group A (no-access), the feedback devices were not visible but recording. In group B (supervisor-access), the feedback devices were visible to the supervisor only. In group C (full-access), both the participant and the supervisor had visual access. RESULTS: The two main outcome variables were the percentage of ventilations within the tidal volume target range (4-8mL/kg) and the number of intubation attempts. Group C achieved the highest percentage of ventilations within the tidal volume target range (full-access 63.6%, supervisor-access 51.0%, no-access 31.1%, P < .001) and the lowest mask leakage (full-access 34.9%, supervisor-access 46.6%, no-access 61.6%; A to B: P < .001, A to C: P < .001, B to C: P = .003). Overall, group C achieved superior ventilation quality regarding primary and secondary outcome measures. The number of intubation attempts until success was lowest in the full-access group (full-access: 1.29, supervisor-access: 1.77, no-access: 2.43; A to B: P = .001, A to C: P < .001, B to C: P = .015). CONCLUSIONS: Our findings confirm that direct visual access to feedback devices for supervisor and trainees alike considerably benefits outcomes and can contribute to the future of clinical education.