Apple Watch blood pressure is one step closer to reality

Rockley Photonics' blood pressure study is good news for wrist-based health tracking
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Apple Watch blood pressure tracking is one step closer to reality, after one of Apple's hardware partners reported successful trials of its sensor tech.

Health sensor company Rockley Photonics, which already lists Apple as a customer, has developed an infrared (IR) spectrophotometer-based sensor technology, which it says can monitor blood pressure non-invasively.

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It's has been conducting its own in-house pilot human study with a view to performing a larger study on the capabilities of the technology.

That pilot human study examined whether its laser-based approach and advanced algorithms could match up to the method that blood pressure monitoring wearables currently on the market adopt. The likes of the Samsung Galaxy Watch 4 use optical PPG sensors, but require calibration with a cuff monitor to offer reliable blood pressure monitor readings.

The Rockley pilot study featured 40 people using its photonics-based sensor, which was worn on the wrist by participants, and captured over 480 total measurements.

Apple Watch blood pressure is one step closer to reality

And according to the company, the results showed a strong correlation with control blood pressure readings from a cuff.

“Following the recent success of our core body temperature studies, the results of our pilot blood pressure study using wrist-based measurement are extremely encouraging,” said Dr. Hooman Abediasl, Senior Vice President of Product Engineering at Rockley.

“These positive results represent a huge step forward in validating our sensing solution and its ability to deliver powerful multi-biomarker functionality in a highly manufacturable wearable form factor.”

Rockley, who already says it has contracts with big global manufacturers, including six of the top ten players in the wearable market, also believes it has the technology capable of measuring a host of other biomarkers including core body temperature, body hydration, alcohol, lactate, and glucose.

This blood pressure study, which was conducted with IRB approval by the WIRB-Copernicus Group Institutional Review Board (WCG IRB), also revealed that Rockley's photonics sensor also performed well when reading heart rate and heart rate variability, against electrocardiogram equipment.

Apple Watch blood pressure is one step closer to reality

Could a future Apple Watch be capable of non-invasively monitoring blood pressure?

If Rockley can match that stronger correlation with a traditional blood pressure monitor on a much larger scale study, then it would be pretty sizeable news for the wearable space.

Currently, Samsung smartwatches use the PPG optical sensor to take blood pressure readings but the sensor requires cuff calibration to offer accuracy on par with traditional monitors.

And the Huawei Watch D, which has just been released in China, actually uses air-filled cuffs that attach to the inside of the watch strap.

Taking the cuff calibration completely out of the equation would mark a major step for serious health monitoring from the wrist.

Delivering non-invasive blood pressure monitoring is definitely already on the agenda for a host of wearable makers. Both Fitbit (CTO, Eric Friedman interview) and Zepp Health (COO, Mike Yeung interview) have stated on record to Wareable that they’re pursuing the technology in the past.

Rockley's next steps will likely now be to expand on this initial study and look to explore how reliably they can track other promised biomarkers. We're sure the rest of the wearable world will be keeping a very close eye on its progress.

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Michael Sawh


Michael Sawh has been covering the wearable tech industry since the very first Fitbit landed back in 2011. Previously the resident wearable tech expert at Trusted Reviews, he also marshaled the features section of

He also regularly contributed to T3 magazine when they needed someone to talk about fitness trackers, running watches, headphones, tablets, and phones.

Michael writes for GQ, Wired, Coach Mag, Metro, MSN, BBC Focus, Stuff, TechRadar and has made several appearances on the BBC Travel Show to talk all things tech. 

Michael is a lover of all things sports and fitness-tech related, clocking up over 15 marathons and has put in serious hours in the pool all in the name of testing every fitness wearable going. Expect to see him with a minimum of two wearables at any given time.

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