The Apple Watch is Apple’s first new product for half a decade, but a serious problem for tattoo lovers seems to have escaped their testing. A large number of tattooed customers with black ink on their arms have been complaining that basic functions of the watch are disrupted by the ink, leaving their watch almost useless to wear on their usual wrist. Social media users have been posting with the hashtag #tattoogate to show their annoyance and alert Apple to the problem.
The watch’s locking mechanism should deactivate when it senses that it is placed on to the skin, but on a tattooed arm the watch stays locked, rendering it almost useless. In addition, the watch does not provide the physical alerts that notify wearers to new messages when placed against tattooed skin. The Apple Watch has a sensor similar to those in the Microsoft Band and Fitbit Charge HR which uses green LED lights and photodiodes to calculate heart beat frequency by detecting the reflected light from blood flowing through the wrist. However readings from a tattooed area of the body are significantly different to a non-tattooed area on the same person.
An Apple support page has been updated to state that the density, colour and patterns of tattoos can confuse the watch’s sensors and make it difficult to accurately determine heart rate. The tattoos can block light emitted from the sensor and so can interfere with heart rate monitor readings. Apple say “If you’re not able to get a consistent reading because of any of these factors, you can connect your Apple Watch wirelessly to external heart rate monitors such as Bluetooth chest straps”. However, Apple’s article doesn’t mention that other functions can be affected too, such as the skin sensor which activates security features and forces users to enter a passcode when the watch has been taken off the wrist.
In addition to tattoos, the heart rate monitor can be affected by the way that blood travels through the skin, known as skin perfusion, which is different for everyone and can be an issue for those exercising in cold temperatures. Rhythmic movements such as tennis can also interfere with the accuracy of the watch’s heart sensor. Apple’s support page reminds users that the watch makes use of an accelerometer, GPS in the iPhone with which it’s paired and other activity sensors along with the heart rate monitor.
Tattoogate seems to have come as an unexpected flaw to Apple, as Apple employees at stores across the globe have told customers that they weren’t aware of any issues. The problem seems to be separate from a further issue with taptic engines in the watch which can break down over time, causing watch shortages in stores as Apple looks into the issue. A number of the parts supplied by Chinese company AAC Technologies Holdings Inc were found to be defective and AAC Technologies suffered an 8% drop in shares following the news.
While issues with suppliers for parts such as displays or haptics engines are normal for new products, there had been no known problems with tattooed skin prior to the Apple Watch’s launch. The Apple Watch is not limited to its fitness features, but these are very important for some and accurate heartbeat readings play into the tracking that some people use for their sport and recreational activities. More than just fitness tracking, for people with tattooed arms their Apple Watches are sometimes unable to recognise that they are even alive and have a heartbeat at all, which does demonstrate a significant issue.
Surprisingly, the issue is not native to the Apple Watch and users of other watches and fitness trackers have been complaining about the problem for months- the FitBit HR and Scosche Rhythm+ have both come under fire for not working properly on tattooed skin. These problems were not well reported as they sold in much lower quantities than the Apple Watch, which has been estimated at one million sales in the United States alone.
At least tattoogate will be a lesson for the future for all fitness tracker and smartwatch makers who will hopefully be able to make these type of gadgets work for all. Until then, you shouldn’t buy the Apple Watch if you have a wrist tattoo as it may not even be able to tell that you’re alive.