Thermometer app from Google utilises infrared sensor to allow users to take temperature using their phone

Google has shared insight into the development of its new Thermometer app for smartphones, which forms part of the January pixel feature drop for the Pixel 8 Pro and enables users to scan someone’s forehead with their smartphone in order to measure body temperature.

The app uses an infrared sensor for body temperature measurement, which is installed next to the rear camera, and requires the user to point the rear camera at their forehead and “sweep across”, taking temperature from the temporal artery. The data from the infrared sensor is then passed to an algorithm which calculates the temperature.

During development, Google describes how the team sought to find a way to support users to hold the phone close to their foreheads to optimise temperature taking, without touching skin in order to prevent the spread of germs. “We found in testing that telling someone to bring their phones within a half inch of their forehead just by estimating was very difficult,” explains Toni Urban, Pixel product manager with a focus on health experiences. “When you use most apps, you’re looking at the screen – but that’s not the case here if you’re using it on your own forehead.”

As such, the team decided to utilise another sensor – the laser detection autofocus sensor, which enables the phone to ‘know’ when it is in the best position to take a reading. Google has also implemented haptics and audio instructions to guide users in sweeping the phone across the forehead to locate the temporal artery.

Clinical trials, Google states, have demonstrated that the software algorithm was capable of calculating body temperature between the ranges of 96.9°F – 104°F, meaning it is “about as accurate as other temporal artery thermometers”.

On accessibility, Toni notes that the app has been built to run on the phone without an internet connection. “It’s something that’s available even if you are traveling or in an area without cell phone reception. The idea was to make sure that every person can reliably use this tool.”

Last month, the app received the DFA’s De Novo classification following an “exhaustive review” in order to enable launch in the United States.

Read more about the app here.

For more health tech news on a global scale, visit HTN International, where we share news, interviews, research and more on digital health from across the world. In other news from Google, we shared how they piloted generative AI to tackle administrative and operational challenges; collaboration between Google, Microsoft and OpenAI on frontier AI models; and how Google Health combined large language models with AI vision encoders for x-rays.