Usability of Automated External Defibrillators: A Randomized, Comparative Simulator Study

Abstract

The aim of this study was to investigate whether one particular automated external defibrillator (AED) is superior to another in use by a layperson such that there is a clinically relevant difference from first contact with the device to the time of shock delivery (TimeToShock (TTS)). Causes for interaction problems and delays were analyzed. The study was conducted as a randomized, two-arm manikin study using the AED training devices “Lifepak CR-T AED Trainer” (Medtronic Physio-Control) and “AED Trainer 3” (Philips Medical Systems). In each study arm, the participants used one of the AEDs in a simulated resuscitation. The interaction was recorded by a mobile eye tracker. The TTS was compared with the Wilcoxon rank-sum test. The study was conducted with 28 participants inexperienced in AED use. A significant difference (p < 0.05) in TTS was measured at 32.5 s median between the two devices (61 s (IQR: 58 s–76 s, range: 51 s–115 s) for the AED Trainer 3 and 93.5 s (IQR: 91 s–103 s, Range: 80 s–129 s) for the Lifepak CR-T AED Trainer). Causes of delays and interaction problems included differences in the use of voice instruction (length, pauses, and terminology), iconography on the device and electrodes, and device opening mechanisms. The measured clinically relevant difference can be attributed to the usability of the interaction elements, which differ significantly between the devices. Besides specific design elements, the extent of user guidance provided by the AEDs is crucial for efficient and error-free interaction.