It requires users to place their finger on the rear-facing camera lens which will detect the colour changes as blood pumps into and out of your digit.
The data won’t be comparable to that from a wearable device, which is able to continuously monitor the wearer’s heart rate throughout the day.
Jack Po, a product manager at Google Health, announced the features in a news briefing – noting that doctors also count patients’ respiratory rate by watching their chest rise and fall.
The new feature in the Fit app requires a user to point the phone’s front-facing camera at their head and chest, positioning themselves within the frame on the screen.
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According to internal studies the feature is accurate to within one breath per minute for people both with and without underlying conditions.
The heart rate monitoring system was accurate to within 2% and has been tested on a range of skin tones.
The Google Health teams plans on publishing a scientific paper with the data from these evaluations.
Before the feature is rushed to other Android devices Google wants to study how well it works on these smartphones.
It is only marketed as a wellness app, rather than something which can perform a medical diagnostic function which would require regulatory approval, although that may be something they look into in the future, Mr Po said.