The lawsuit, filed on Saturday on behalf of a group of New York residents and Apple users, alleges the pulse oximeter technology that measures blood oxygen levels is “significantly less accurate in measuring blood oxygen levels based on skin colour”.
It is based on studies conducted during the Covid-19 pandemic that confirmed the clinical significance of “racial bias” of pulse oximetry.
Pulse oximeters work by shining visible and infrared light through the wearer’s skin and then, based on how much the light is absorbed, it estimates the percentage of oxygen in a red blood cell using a series of sensors.
The lawsuit notes that while traditional fingertip pulse oximeters used by clinicians are capable of measuring blood oxygen levels and heart rate, devices such as “the Product” – the Apple Watch – make blood oxygen measurements from the wrist.
It claims that the algorithms designed for fingertip sensing are “inappropriate” when based on wrist measurements, adding that they can lead to “over 90 per cent of readings being unusable”.
“Though one recent study concluded the Product was able to detect reduced blood oxygen saturation in comparison to medical-grade pulse oximeters, this fails to recognise the failings of pulse oximetry in general with respect to persons of colour,” the lawsuit said.
The latest version of Apple Watch costs between $400-$800, a “premium price” – based on features such as its “Blood Oxygen” app – according to the lawsuit.
Plaintiff Alex Morales in New York “would not have purchased the Product or paid as much if the true facts had been known, suffering damages,” it said.
While Apple notes on its website that “permanent or temporary changes” to the skin, such as from tattoos, may cause affect its product’s blood oxygen reading, the company does not explicitly mention how the values may be affected by a person’s natural skin colour.
The lawsuit alleged Apple “misrepresented and/or omitted the attributes and qualities of Apple Watch” and that it did not “incorporate biases and defects of pulse oximetry with respect to persons of darker skin tone”.
It has called for a jury trial, alleging that Apple committed fraud and unjustly enriched itself by misrepresenting the capability of its product.