Apple Watch may not be able to detect users’ wrists through certain tattoos

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Date: Tuesday, April 28th, 2015, 08:25
Category: Apple Watch, Hardware, News, Wearables


Your snazzy new Apple Watch may not be able to detect your wrist if there’s a tattoo in the way.

A Reddit user posted on Monday that his Apple Watch didn’t receive notifications and would lock when placed on his tattooed wrist. Before trying to contact Apple, though, he tested the Watch against his unmarked hand, which suddenly allowed it to work as intended.

Turning off wrist detection entirely was said to solve the problem, but at the expense of features like Apple Pay.

The Apple Watch’s wrist detection feature relies on sensors located on the back of the device which also serve as a heart rate tracker through a method known as photoplethysmography. Through the flashing of infrared and/or green LED lights, the Watch can detect blood flow. Dark skin color could theoretically affect accuracy, although Apple states that the Watch will increase LED brightness and sampling rate to deal with tough reads.

The issue could be down to the materials that tattoo ink is made from. Many pigment bases are derived from heavy metals, like mercury, copper, or nickel, which may interfere with the sensors.

Stay tuned for additional details as they become available.

Via Reddit and AppleInsider

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2 Responses to “Apple Watch may not be able to detect users’ wrists through certain tattoos”

  1. @JasonOGrady edge case

  2. I am amazed of how people willingly inject under their skin cancer causing heavy metals such as mercury, lead, antimony, beryllium, chromium, cobalt nickel and arsenic. Futhermore, some of these heavy metals in tattoos burn during MRI procedures.

    Now why would people think that a skin tattoo whose main purpose is to reflect light, work well with a heart rate detector trying to measure the blood vessels’ absorption of light under the skin…