Usability engineering methods for assessing the human-machine interface of automated external defibrillators

  • Hannah Torney

Student thesis: Doctoral Thesis


Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Rapid treatment through cardiopulmonary resuscitation (CPR) and defibrillation shock(s) is vital for survival. For this reason, defibrillation by lay-rescuers without medical training is encouraged, and public access defibrillators (PADs) are becoming more commonplace. To ensure that lay-rescuers can use PADs without safety concerns or complications, the devices undergo usability testing in the form of simulation studies prior to approval by medical device regulatory authorities. The design of PADs have changed over the past decades, but simulation testing remains largely unchanged.

This thesis employs human-computer interaction methodologies to conduct additional usability and human factors assessment of PADs, comparing user interaction of many currently marketed PADs. The thesis presents four studies: (1) an in-person simulation usability study of a PAD; (2) a monitor-based eye-tracking study investigating visual attention on the user interface (UI) of 10 PADs when a potential user views their 2D image; (3) a wearable eye-tracking study to investigate visual attention on 5 PADs when potential users physically interact with the device, and to assess change in eye-gaze behaviour from the previous study; and (4) a remote synchronous usability testing of a PAD which could be compared with the in-person simulation study of the same device, to determine if remote usability testing of PADs is reasonable and provides comparable results to in-person testing.

These studies were the first of their kind, indicating that when viewed on a monitor, no one PAD visually guides the user through the ideal user journey. Visual attention on PADs change when users physically interact with the devices, as users became slower to locate important areas of the user interface. The final study confirmed the feasibility of remote usability testing, suggesting it is more appropriate in formative usability studies to determine understanding of the UI, as time-based metrics may not be reflective of actual use.
Date of AwardMay 2022
Original languageEnglish
SponsorsHeartSine Technologies Ltd
SupervisorRaymond Bond (Supervisor), Dewar Finlay (Supervisor) & Justin Magee (Supervisor)


  • Public access defibrillator
  • Usability
  • Human computer interaction
  • Automated external defibrillator

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