Fig. 5

Comparison of NASA-TLX scores between AR-US and S-US groups: A measure of cognitive workload and usability in ultrasound-guided CVC placement. A and B The NASA-TLX scores of trainees with different seniority, with AR-US and S-US. C and D The NASA-TLX scores of trainees of different gender, with AR-US and S-US. NASA-TLX: NASA Task Load Index. CVC: Central venous catheter. UGY: Undergraduate students. PGY: Postgraduate physicians. AR-US: Augmented reality ultrasound using a head mounted display. S-US: Standard ultrasound without visual overlay. *p-value < 0.05