Will Apple Watch be suitable for the masses?
By Raif Karerat
WASHINGTON, DC: The Apple Watch is host to a bevy of intriguing features, one of which is the heart rate monitor. The technology relies on two sets of lights and sensors on the back of the watch — one sends out and receives visible light, while the other operates in the infrared part of the spectrum.
According to Fusion, the design — which is central to most smartwatches that include heart monitors — is infamously inaccurate, but the problems may only be exacerbated if you have darker skin.
The technology is based on a laboratory technique called photoplethysmography, which uses a “pulse oximeter” to measure the components of the blood. A light pulse is sent through the skin and picked up by a sensor. Based on how the light scatters, the sensor can measure how oxygenated the blood is, which allows one to calculate heart-rate based on how often fresh, arterial blood is pumping through.
Put simply, since the measuring device is based off of light, it stands to reason it might not be as effective when measuring darker subjects.
The skin on the back of the wrist tends to be darker, too, especially for people with more melanin. “The light has to penetrate through several layers … and so the higher the person is on the Fitzpatrick scale (a measure of skin tone), the more difficult it is for light to bounce back,” explained Basis COO Bharat Vasan to CNET.
If the only way to counter the measuring disparity is to brighten the light pulse, individuals with darker skin might then experience greater drain on their watch battery.
As the Apple watch inundates itself in the market after its recent release, time will inevitably tell if Apple designers built a product that is truly accessible by the masses.