Objective: Many public access defibrillators (PADs) incorporate computer programs to provide audiovisual feedback to assist the user to deliver cardiopulmonary resuscitation (CPR) according to current international guidelines. This usability study assessed if a PAD integrated with a real-time audiovisual CPR feedback system can guide lay-users to optimum chest compression rates, and if it is detrimental to chest compression depth. Methods: Randomly selected volunteers (15+ years) were recruited for two experiments. Experiment 1 $(n = 156)$ assessed the time taken to achieve the “good speed” audio prompt (i.e., perform compressions at a rate of 100–120 compressions/min) and chest compression fraction (CCF). Experiment 2 $(n = 140)$ assessed the effect of rate-only CPR feedback on chest compression depth. Two devices of the same model were used: one with CPR rate feedback and the other with CPR feedback disabled. The difference in compression depths and CCF was assessed. Results: Experiment 1: A total of 136 (87.2%) participants achieved “good speed” within 45 s with a mean CCF of 90.3% recorded. Experiment 2: The device with feedback lead to a mean (standard error—SE) depth of 24.61 mm (0.99) compared with 20.08 mm (0.96) for the feedback disabled device. Analysis of covariance provided a mean significant difference (SE) of 4.52 mm (1.38 mm; p-value = 0.001) favoring the device with CPR rate feedback. Conclusions: CPR rate-only feedback was not detrimental to chest compression depth and suggests rate-only feedback may improve compression depth. Significance: The incorporation of clear, intuitive, audiovisual CPR feedback systems can assist lay-users to optimize compression rates and maintain a high CCF.
Bibliographical noteReference text:  Atwood C., Eisenberg M.S., Herlitz J., Rea T.D. Incidence of EMS-treated out-of-hospital cardiac arrest in Europe. Resuscitation 2005;67:75-80
 Go A.S., Mozaffarian D., Roger V.L. et al. Heart disease and stroke statistics – 2014 update: a report from the American Heart Association. Circulation 2014;129:e28-e292
 Handley A.J., Koster R., Monsieurs K., Perkins G.D., Davies S., Bossaert L. European Resuscitation Council Guidelines for Resuscitation 2005. Section 2. Adult basic life support and use of automated external defibrillators. Resuscitation 2005;67S1:7-23
 Nichol G., Stiell I.G., Laupacis A., Pham B., De Maio V.J., Wells G.A. A cumulative meta-analysis of the effectiveness of defibrillator-capable emergency medical services for victims of out-of-hospital cardiac arrest. Ann Emerg Med 1999;34:517-525
 Hallstrom A.P., Ornato J.P., Weisfeldt M. Public-access defibrillation and survival after out-of-hospital cardiac arrest. N Engl J Med 2004 ;351(7) :637-646
 Sunde K., Wik L., Naess P.A., Grund F., Nicolaysen G.,. Steen P.A. Improved haemodynamics with increased compression-decompression rates during ACD-CPR in pigs. Resuscitation 1998;39:197–205
 Meaney P.A., Bobrow B.J., Mancini M.E. et al. CPR Quality: Improving Cardiac Resuscitation Outcomes both Inside and Outside the Hospital: A Consensus Statement from the American Heart Association. Circulation 2013; 128:417-435.
 Yang Z., Li H, Yu T, et al. Quality of chest compressions during compression-only CPR: a comparative analysis following the 2005 and 2010 American Heart Association guidelines. Am Jour of Emerg Med 2014; 32:50-54.
 Wik L., Kramer-Johansen J., Myklebust H. et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. Jour Am Med Assoc 2005;293: 299-304.
 Yeung J, Okamoto D, Soar J, Perkins D. AED training and its impact on skill acquisition, retention and performance.A systematic review of alternative training. Resuscitation 2011;82(6):657-664
 Wik L, Myklebust H, Auestad BH, Steen PA. Twelve-month retention of CPR skills with automatic correcting verbal feedback. Resuscitation 2005;66:27—30
 Kalbfleisch, J. D. and Prentice, R. L. (1980), The Statistical Analysis of Failure Time Data, New York: John Wiley & Sons.
 Nolan J., Soar J.P., Zideman D.A., et al. European Resuscitation Council Guidelines for Resuscitation 2010 Section 1. Executive summary. Resuscitation 2010;18:1219-1276
 Berg R.A., Hemphill R., Abella B.S., et al. Part 5: adult basic life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2010;122 (18 Suppl 3):S685-S705
 Morrison LJ, Deakin CD, Morley PT et al. Part 8: Advanced life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Circulation 2010; 122:s345-s421
 Koster RW, Baubin MA, Bossaert LL, et al. European Resuscitation Council Guidelines for Resuscitation 2010 Section 2. Adult basic life support and use of automated external defibrillators. Resuscitation 2010;81:1277-1292.
 Cheng A., Overly F., Kessler D., Nadkarni VM. et al. Perception of CPR quality: Influence of CPR feedback, Just-in-Time CPR training and provider role. Resuscitation 2015;87:44-50.
 Fischer H., Gruber J., Neuhold S et al. Effects and limitations of an AED with audio-visual feedback for cardiopulmonary resuscitation: A randomized manikin study. Resuscitation 2011;82:902-907
 Abella B.S., Alvarado J.P., Myklebust H. et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. J Am Med Assoc, 2005;293:305-
 Andre A.D., Jorgenson D.B., Froman J., Snyder D.E., Poole J.E. Automated external defibrillator use by untrained bystanders: Can the public-use model work? Prehosp Emerg Care 2004;8:284-291.
 Eames P., Larsen P.D., Galletly D.C., Comparison of Ease of User of Three Automated External Defibrillators by Untrained Lay People. Resuscitation 2003;58:25-30
 Marsch S., Tchan F., Semmer N. et al. Performance of first responders in simulated cardiac arrests. Critical Care Medicine 2005;33.5:963-967
- human-machine systems
- human-computer interaction
- user experience
- automated audio-visual user feedback
- user interfaces