A new patent explains how Oura could mitigate signal strength variances caused by users’ skin tone.
Smart ring brand Oura is working on a way to detect the wearer’s skin tone to yield more accurate health metrics.
In a new patent filing identified by Wareable, Oura remarks that the diversity of skin tones produces different levels of “noise” that can decrease the accuracy of physiological data captured by the device’s sensors.
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The company points out that, when measuring metrics like blood oxygen content, “the user’s skin tone may contribute to the signal strength of the received light signals.”
It continues: “For instance, darker skin tones may absorb more light as compared to lighter skin tones, which may affect the amount of light received at the photodetectors, and therefore affect the determined blood oxygen saturation metrics. As such, failing to account for varying skin tones may increase the inaccuracy of the physiological data collected using optical components.”
Oura intends to rectify this by using a method of detecting skin tone and then factoring into the results when recording metrics. The parent explains how the optical sensor could take a series of light-based readings using infrared, green and red lights.
“Varying skin tones may absorb IR light at approximately the same level, meaning that IR absorption may be used as a reference point that is used to compare absorption levels (and therefore skin tone metrics) for other wavelength ranges,” the patent continues.
“As such, by comparing the differences between red and green light absorption relative to IR absorption, techniques described herein may be used to estimate a skin tone metric for the user.”
The patent goes on to explain, in some detail, how skin tone knowledge could be used to yield more accurate measurements of physiological data.
According to the filing, that could mean adjusting the power level of the optical transmitter, adjusting a burn-time of the optical transmitter, or adjusting the algorithm for analysing the light readings. All could account for the variances in skin tone.
“In the case of darker skin tone metrics that exhibit higher absorption rates, the wearable device may increase a power level applied to light-emitting components in order to account for the higher absorption levels and increase the quality of physiological data collected via the wearable device,” Oura writes.
The technology within the patent appears as if it could progress beyond inherent inventor bias – conscious or not – that often means tech has often worked more effectively for the demographic involved in their creation
Examples include voice assistants struggling to comprehend underrepresented groups, and wearable fitness technology being slow to prioritize female-centric health tracking – another area where Oura excels.
There have been greater efforts to redress the balance recently, through tools like Google Pixel phones’ Real Tone photography mode, which aims to capture more authentic skin tones to counter how camera hardware has historically been designed.
Google says: “Historically, camera technology has excluded people of color, resulting in unflattering photos for those with darker skin tones. We improved our camera tuning models and algorithms to more accurately highlight diverse skin tones with Real Tone software.”
Oura’s new patent can be somewhat likened to this. It is using advanced tools to potentially ensure a more representative piece of technology makes it onto the fingers of users.
An Oura spokesperson said: “As a company committed to innovation, we are continually looking for ways to evolve our patent portfolio and develop new technologies to better serve our members. While we’re excited about our ongoing work and research in this area, we can’t comment on specific patents or future plans at this time.”
