Eye-tracking during simulation-based echocardiography: a feasibility study

Due to the technical progress point-of-care ultrasound (POCUS) is increasingly used in critical care medicine. However, optimal training strategies and support for novices have not been thoroughly researched so far. Eye-tracking, which offers insights into the gaze behavior of experts may be a useful tool for better understanding. The aim of this study was to investigate the technical feasibility and usability of eye-tracking during echocardiography as well as to analyze differences of gaze patterns between experts and non-experts.

Nine experts in echocardiography and six non-experts were equipped with eye-tracking glasses (Tobii, Stockholm, Sweden), while performing six medical cases on a simulator. For each view case specific areas of interests (AOI) were defined by the first three experts depending on the underlying pathology. Technical feasibility, participants' subjective experience on the usability of the eye-tracking glasses as well as the differences of relative dwell time (focus) inside the areas of interest (AOI) between six experts and six non-experts were evaluated.

Technical feasibility of eye-tracking during echocardiography was achieved with an accordance of 96% between the visual area orally described by participants and the area marked by the glasses. Experts had longer relative dwell time in the case specific AOI (50.6% versus 38.4%, p = 0.072) and performed ultrasound examinations faster (138 s versus 227 s, p = 0.068). Furthermore, experts fixated earlier in the AOI (5 s versus 10 s, p = 0.033).

This feasibility study demonstrates that eye-tracking can be used to analyze experts and non-experts gaze patterns during POCUS. Although, in this study the experts had a longer fixation time in the defined AOIs compared to non-experts, further studies are needed to investigate if eye-tracking could improve teaching of POCUS.