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.

Occupational reintegration after severe burn injury: a questionnaire study.

BACKGROUND: As a consequence of improved survival rates after burn injury occupational reintegration of burn survivors has gained increasing significance. We aimed to develop a precise patient questionnaire as a tool to evaluate factors contributing to occupational reintegration. MATERIAL AND METHODS: A questionnaire comprising 20 questions specifically evaluating occupational reintegration was developed under psychological supervision. The single-center questionnaire study was implemented in patients with burn injuries who were admitted to the 6­bed burn intensive care unit (BICU) of the General Hospital of Vienna, Austria (2004-2013). The questionnaire was sent to burn survivors of working age (18-60 years) with an abbreviated burn severity index (ABSI) of 6 or greater, a total burn surface area (TBSA) of 15% or greater, and a BICU stay of at least 24 h. RESULTS: A total of 112 burn survivors met the inclusion criteria and were contacted by mail. Of the 112 patients 11 (10%) decided to participate in the study and 218/220 questions (99%) in 11 patients were answered. Out of 11 patients 7 (64%) reported successful return to work and 4 of 11 (36%) did not resume their occupation. Advanced age, longer BICU and hospital stays, higher TBSA, burn at work, lower education, and problems with esthetic appearance seemed to impair patients' return to their occupation. CONCLUSION: When implementing the questionnaire, severely burned patients with higher age, lower education, and longer hospital and BICU stay seemed at high risk for failed reintegration in their profession after burn injury.