Apple Watch’s Handwashing Detection Was in Development for Years

Apple has made a handful of new and noteworthy announcements at last week’s WWDC — one of the most noteworthy being a new watchOS for Apple Watch that places focus on reminding wearers to wash their hands to avoid contracting or spreading COVID-19.

“In a first-of-its-kind innovation for a wearable, Apple Watch automatically detects handwashing to initiate a 20-second countdown timer,” the tech giant said in a release. “If the wearer finishes early, they’ll be prompted to keep washing.”

The feature, which is built directly into the forthcoming version of watchOS, is designed to work like fitness tracking in a number of ways:

Washing hands properly for at least 20 seconds can help prevent the spread of illness. In a first-of-its-kind innovation for a wearable, Apple Watch uses the motion sensors, microphone, and on-device machine learning to automatically detect handwashing motions and sounds. It then initiates a 20-second countdown timer, and if the user finishes early, they will be prompted to keep washing. Apple Watch can also conveniently remind the user to wash their hands when they return home.

The Health app on iPhone will show frequency and duration of the user’s handwashing, as well as information on the importance of handwashing, as it relates to overall health. Sounds used to detect handwashing are not automatically recorded or saved by the Health app or Apple Watch.

Once automatically detected, handwashing will begin a 20-second timer.

While the feature is releasing in an appropriate global climate considering the COVID-19 outbreak, Apple has actually been working on the feature for a number of years, explains a new report from TechCrunch. In typical Apple fashion, the product was a result of years of trial and error, explains Apple VP of Technology Kevin Lynch.

The Apple Watch handwashing feature relies on three cues, explains the report:

The accelerometer is the key piece of hardware here, waiting for the specific handwashing pattern — which apparently adopts a number of different methods, depending on who’s actually doing the scrubbing.

Along with motion, the app listens for the sound of running water. Even that’s not enough, though — after all, eco sinks have become increasingly popular, meaning that there’s often less water sound to be listening for.

The sound of squishing soap takes care of that last bit. It’s got a unique enough audio signature so as to confirm that handwashing is taking place.

The latest Apple Watch iOS will also introduce sleep tracking, taking a “holistic approach to sleep” by providing tools and tracking to help wearers get an appropriate amount of sleep, to go to bed on time, and even create a bedtime routine that’s catered to their individual sleep goals in order to foster a healthier overall immune system.

Another announcement, while less pertinent to fighting COVID-19 directly, is that the iOS 14 will also come with a set of face mask graphics added to Apple’s personalized Memojis.