Assessment of Radiation Therapy Technologists’ Workload and Situation Awareness: Monitoring 2 Versus 3 Collocated Display Monitors

PURPOSE: This study aimed to assess the effect of monitoring 2 versus 3 collocated displays on radiation therapist technologists’ (RTTs) workload (WL) and situation awareness (SA) during routine treatment delivery tasks. METHODS AND MATERIALS: Seven RTTs completed 4 simulated treatment delivery scenarios (2 scenarios per experimental condition; 2 vs 3 collocated displays) in a within-subject experiment. WL was subjectively measured using the National Aeronautics and Space Administration (NASA) Task Load Index, and objectively measured using eye activity measures. SA was subjectively measured using the SA rating technique, and objectively measured using the SA global assessment technique. Two-tailed paired t tests were conducted to test for differences in means when parametric assumptions were satisfied, otherwise Wilcoxon signed-rank tests were conducted. A .05 level of significance was applied to all statistical tests. RESULTS: No statistically and clinically significant differences were observed between monitoring 2 versus 3 monitors on eye tracking measures (blink rate: 9.4 [4.8] vs 9.6 [4.0]; task evoked pupillary response: 0.16 [0.14] vs 0.21 [0.15]; NASA Task Load Index: 34.7 [19.8] vs 35.3 [20.4]; SA rating technique: 19.3 [6.2] vs 19.5 [7.0]; and SA global assessment technique scores: 100 [0] vs 100 [0]). CONCLUSIONS: Our preliminary findings suggest that monitoring 3 collocated displays by 1 RTT does not impact WL and SA compared with monitoring 2 collocated displays. Only 2 of many possible configurations were investigated. If institutions removed the 3rd display based on the results of this study, there could be unforeseen error(s) if that display helped in situations not assessed in this study.