Fig. 7From: Chest compression rate measurement from smartphone videoThree test examples, time in seconds, and compression rate in cpm. Blue line corresponds to compression rate from smartphone app, and red line corresponds to reference rate recorded from the manikin. a Test person 6 (medium length hair), target compression rate 110Â cpm. \(\bar{E}\)Â =Â 6.4, PÂ =Â 90.4. b Test person 4 (short hair), different target compression rates. \(\bar{E}\)Â =Â 5.0, PÂ =Â 85.2. c Test person 3 (long hair in topknot, considered short hair), CPR 30:2. \(\bar{E}\)Â =Â 3.3, PÂ =Â 89.8Back to article page