Health programs available on Google Play and the Apple Inc app store for years provided the same functionality. But a 2017 study found that accuracy varied and uptake of apps remains low.

Officials at Google Health told reporters earlier this week that they advanced the artificial intelligence that powers measurements and plan to detail their method and clinical trial in an academic article in the coming weeks.

The company said in a blog on Thursday that it hopes to roll out the feature to other Android smartphones at an unspecified time, but plans for iPhone are unclear.

Apple’s watch , Google’s Fitbit , and other wearable devices expanded the reach of technologies in continuous heart rate detection to a much larger population.

The focus of the smartphone camera is more ad hoc: users who want to take their pulse place their finger on the lens, which detects subtle color changes corresponding to blood flow. The respiration is calculated from the video of the movements of the upper torso.

Google Health Product Manager Jack Po said the company wants to offer an alternative to manual pulse checks for smartphone owners who only want to monitor their condition occasionally but can’t afford a wearable device.

Po said the technology, which can confuse the heart rate by about 2%, requiring further testing before its use is feasible in medical settings.

The new feature will be available as an update to the Google Fit app .

Google consolidated its healthcare services more than two years ago, aiming to better compete with Apple , Samsung Electronics Co, and other mobile technology companies that invested heavily in marketing wellness-focused offerings.