Fig. 1From: A novel electromagnetic guidance ultrasound system on radial artery cannulation: a prospective randomized controlled triala. Radial artery cannulation using electromagnetic guidance system — Before alignment. The screen shows the actual position (two solid lines), expected route (dotted line), and tip of the needle (the indicator box). b. After alignment. The indicator box changed from red to green after the alignment of the needle. c. After puncture. The actual tip of the needle appeared in the middle of the indicator boxBack to article page