Provides assistance while performing a CPR
The app alternates between the phases for chest compression and rescue breaths in an in an endless loop. In the chest compression phase the the watch will provide a buzz at a rate of 100 rpm for 30 repetitions. A longer buzz introduces an interval of 4 seconds to perform 2 rescue breaths. A ratio of chest compressions to rescue breaths is also displayed in the bottom of the screen.
The number of repetitions for chest compression and rescue breaths, the rpm rate and the duration of the rescue breath phase can be adjusted in the settings. See e.g. CPR on Wikipedia for futher information and updates on the recommendations.
Icon source: https://commons.wikimedia.org/wiki/File:ISO_7010_E003_-_First_aid_sign.svg
