Apple introduced a number of innovations at WWDC 2020. But the handwashing detection caused a lot of excitement. The feature couldn't seem more appropriate in light of the COVID-19 pandemic. The interesting thing is that it took years to develop.
The new watchOS 7 feature, which is designed for hand washing, couldn't seem more appropriate, could it? The Apple Watch will automatically detect whether the user is washing their hands under the new operating system. If this is the case, the popular computer watch will start a timer of 20 seconds. This is the time recommended by the World Health Organization. If the wearer stops washing their hands before the timer runs out, the Apple Watch will politely ask for the user to repeat the process more thoroughly. This is how Apple explains the function:
Health app records statistics

Properly washing hands for at least 20 seconds can help prevent the spread of disease. In a first of its kind innovation for a wearable device, Apple Watch uses its motion sensors, microphone and on-device machine learning to automatically detect movement and sound while washing hands. It then starts a 20-second countdown timer and if the user finishes early, they are prompted to continue washing. Apple Watch can also conveniently remind the user to wash their hands when they return home.
The Health app on iPhone displays the frequency and duration of the user's handwashing, as well as information about the importance of handwashing in relation to overall health. Sounds used to detect handwashing are not automatically recorded or stored by the Health app or Apple Watch.
As soon as hand washing is automatically detected, a 20-second timer starts.
But anyone who thinks that Apple developed the function in a rush is mistaken. In fact, development is said to have started several years ago, long before Corona. Kevin Lynch, Vice President of Technology at Apple, told TechCrunch explained:
Handwashing for Apple Watch was added, along with face masks for Memojis, to the list of COVID-19-related features the company unveiled at last week's WWDC keynote.
However, unlike other rush initiatives the company has taken after the virus hit, the upcoming Apple Watch handwashing app wasn't developed overnight. The feature was the result of "years of work," VP of technology Kevin Lynch told TechCrunch. In typical Apple fashion, the product is the result of years of trial and error, Lynch said.
First watchOS 7 beta shows weaknesses
The new handwashing feature introduced in watchOS 7 requires three important features to work.
The accelerometer is the core of the hardware here, listening for the specific pattern of handwashing – which seems to use a number of different methods depending on who is actually doing the scrubbing.
In addition to movement, the app also listens for the sound of running water. But even that isn't enough - after all, eco-sinks have become increasingly popular, which means there is often less water noise to hear.
The sound of “squeezing” soap takes care of every last bit. The sound signature is unique enough to confirm that hand washing is taking place.
However, according to initial reports, the feature is not yet working reliably. It seems that Apple will have to make further optimizations in order to be able to declare the feature as truly reliable. (Photo by Denys Prykhodov / Bigstockphoto)