title: A trigonometric method to confirm needle tip position during out-of-plane ultrasound-guided regional blockade.
authors.forename: Ban C H
authors.initials: BC
authors.lastname: Tsui
mesh_terms: D006801:Humans; D009339:Needles; D009407:Nerve Block / Q000379:methods*; D018084:Ultrasonography, Interventional / Q000379:methods*