​Rockley Photonics proves hydration tracking in trials

Photonic sensor takes one step forward
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Rockley Photonics has proven its hydration tracking capabilities via preliminary human trials – the company has claimed.

The UK-based sensor company, which has gained attention by being a customer of Apple, has created a photonic biosensor concept device, which is targeting some of the holy grails of wearable sensor tech.

And the company has claimed success in its trials of tracking hydration, non-invasively, from the wrist. In the trial it was able to detect normal 'euhydration' levels 82% of the time – but detected dehydration in participants with 99% success.

That has obvious benefits in the healthcare sector, as well as applications for athletes, and those looking to add an extra dimension to their wellness tracking.

The photonic sensor is capable of tracking water concentration levels in the body. It uses multiple laser wavelengths, which penetrate the skin at varying depths, to assess changes in collagen, lipids, and water content.

​Rockley Photonics proves hydration tracking in trials

Rockley then translates that data into a hydration index, a scale that ranges from severe dehydration to severe hydration.

This is all fairly conceptual stuff at the moment, and Rockley’s sensor is part of its reference design that’s not commercially available.

It’s also working to track glucose and blood pressure non-invasively, which Andrew Rickman, Rockley Photonics CEO, claims is part of a goal to create a holistic look at multiple biomarkers on the body.

"If you look at the group of biomarkers then sharing the search work and how these correlate to particular disorders is the exciting opportunity to be able to early diagnose diseases, to understand the progression of diseases where the treatment is working," he told Wareable in an interview earlier this year.

And Rockley is looking to get FDA approval for some of these features by the end of 2022, which could mean we see them hitting devices in 2023.

It’s not the first to go here. Aura has attempted to monitor hydration via an Apple Watch strap – which took manual readings using bioimpedance. And it’s just launched the Aura Strap 2.

And we’ve seen other connected devices using patches to measure sweat and hydration.

As a supplier of sensors and tech to brands, eventually this stuff will make it to consumer smartwatches and wearables – so it’s an important marker of where the wearables industry is going.

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James Stables


James is the co-founder of Wareable, and he has been a technology journalist for 15 years.

He started his career at Future Publishing, James became the features editor of T3 Magazine and T3.com and was a regular contributor to TechRadar – before leaving Future Publishing to found Wareable in 2014.

James has been at the helm of Wareable since 2014 and has become one of the leading experts in wearable technologies globally. He has reviewed, tested, and covered pretty much every wearable on the market, and is passionate about the evolving industry, and wearables helping people achieve healthier and happier lives.

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