Jim Taylor, a pediatrician and research scientist with Google Health, is well-versed in temperature measurement. His experience in both fields led to his involvement in developing health tools for Pixel phones, including the new body temperature feature in the Thermometer app for Pixel 8 Pro. This addition, released in the January Pixel feature drop, enables users to scan a person’s forehead using their phone to measure body temperature. Clinical trials demonstrated the software’s ability to calculate body temperature within a range of 96.9°F – 104°F (36.1°C – 40°C) to within ±0.3°C when compared with an FDA-cleared temporal artery thermometer, indicating comparable accuracy to other temporal artery thermometers.
Ravi Narasimhan, a research and development technical lead at Google, played a crucial role in creating a miniaturized device with an infrared sensor for body temperature measurement. This innovation eventually evolved into a feature for the Pixel phone, offering a more convenient way to measure body temperature without the need for an additional device.
The body temperature app received the FDA’s De Novo classification, marking a significant milestone as the first smartphone body temperature app in the U.S. It is now available on Pixel 8 Pro.
The Development Process
The Pixel 8 Pro team incorporated an infrared sensor next to the rear camera, initially used for the object temperature feature and later adapted for the body temperature feature. Using this sensor, the phone measures body temperature by scanning the temporal artery when the rear camera is pointed at the forehead. This approach sets it apart from less accurate forehead thermometers that are directed at the center of the forehead. The data captured by the infrared sensor is processed by an algorithm that calculates the temperature, powered by the Tensor G3 chip.
The wide field of view of the Pixel 8 Pro’s infrared sensor, over 130 degrees, can result in sensing heat beyond the forehead if the phone is positioned too far away. Ravi explains that the sensor’s accuracy improves as it gets closer to the arteries, as they are relatively small compared to the sensor’s wide sensing range.
