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How lasers and lidar are changing the way wearables track health

“There is this battle going on between consumer wearables measuring your health and wanting to get more sophisticated, and the medical device companies trying to miniaturize and fight their way out of hospitals.”

This is how Dr. Andrew Rickman, CEO of Rockley Photonics, described the current state of the wearable industry in an interview with Digital Trends. The company is uniquely placed to not only understand how consumer and medical technology in wearables has started to converge, but also to help make it a reality with a unique, and incredibly accurate new health sensor technology.

Rockley, Bioptx, and Apple

It’s possible you’ve never heard of Rockley Photonics, but you’ve certainly heard of Apple — one of Rockley’s top customers. Rockley makes optical sensors and related components for consumer products and the healthcare industry, and most will be used in wearables. It’s therefore likely that existing Rockley technology is found in the Apple Watch’s health monitoring sensor array.

Dr Andrew Rickman, CEO of Rockley Photonics.
Dr. Andrew Rickman, CEO Rockley Photonics Image used with permission by copyright holder

In February this year, Rockley announced Bioptx, a platform designed to bring measurement of multiple biomarkers — including blood pressure, core body temperature, lactate, glucose, and a lot more — into a single sensor for non-invasive, continuous, and personal health tracking. Notably, Apple has also been linked to research into bringing non-invasive glucose monitoring and blood pressure monitoring to consumer wearables for some time.

But what makes the platform Rockley has developed so special, and why is it such a breakthrough? Rickman explained:

“The monitoring technology in the devices that exist today is very simple, and there’s little differentiation across consumer devices. Your heart rate is measured with a green LED, your blood is measured with a couple of other LEDs, and an ECG is an electrode on the back of the device. None of that technology is in any way advanced technology, and they are available to everybody.”

“What we are bringing is a powerful optical instrument, shrinking a $100,000 instrument down onto a chip, using a unique semiconductor process that’s not available to anyone else,” he continued, describing the company’s new technology. “That instrument collects incredibly rich data that we extract to measure, amongst other things, hydration, lactate, and blood pressure. That’s the breakthrough. Instead of a couple of LEDs and electrodes, what we’ve added is an instrument that measures multiple biomarkers with an unprecedented level of capability and accuracy.”

Lasers, not LEDs

Rockley’s instrument uses silicon photonics-based lasers to track biomarkers, not LEDs, and it’s a technology that hasn’t been used on a consumer wearable before. When you hear the word “lasers,” it’s tempting to think this means a shaft of red light beaming into your skin. But, of course, it’s not that. To explain, Rickman drew comparisons with lidar technology used on autonomous cars, the Apple iPad and iPhone, and for super secure face unlocking systems.

“It is a separate chip to the LEDs that you’d see in a regular wearable, and instead of electrical signals it uses optical signals,” Rickman said. “Our chip works using infrared and laser light at harmless power levels. The footprint on the back of a wearable is smaller than the space taken up by the LED array. It’s made using a silicon photonics process, and we needed to develop a completely new semiconductor manufacturing process, which is arguably the most sophisticated in the world, and unique to us. It has taken us nine years to develop.”

Why can’t a regular green or red LED system be used? After all, they’re a staple of existing health monitoring wearables.

“Those [LED] wavelengths pick up hemoglobin beautifully,” Rickman explained, “but when you think about blood sugar, lactates, and other metabolites, those LEDs don’t have the performance. They aren’t looking in the right part of the optical spectrum.”

Wearable health tracking like never before

Rockley Photonics describes its platform as a clinic on your wrist, bringing together the measurement of multiple different biomarkers, many of which may have previously required blood tests to assess, into a single, tiny, non-invasive sensor. Rickman explained why this is advantageous.

“When you measure one biomarker you get a one-dimensional picture of a person, but when you measure 10 biomarkers together, what’s contained in that relatively small amount of information can represent many different conditions the individual may be suffering from.”

Rockley Photonics wearable device.
Rockley Photonics wearable device Image used with permission by copyright holder

It’s when you hear about how the silicon photonics-based sensor measures these biomarkers the complexity becomes clear.

“Hydration is understood by analyzing the difference in how your skin absorbs water and the lipids in your skin, and it’s that ratio we’re measuring. The spectrum of light is dominated by water, and that level goes up and down with your hydration. Until now the only other way to get this level of detail was by taking a blood sample. Core temperature is even more bonkers. We are able to measure it using another spectroscopic technique, as the water in your body, fortunately, changes its properties slightly with temperature, and we measure those changes using a gradient to give us core body temperature readings.”

For blood pressure, the laser examines “bumps in the signal” after it sees peak pulse rates, which — depending on whether they are large or small — defines whether blood pressure is high or low. It sounds simple put like this, but Rickman said it’s very difficult for a laser to measure this accurately. Existing technologies can’t match this rich level of cardiovascular examination, and have therefore so far failed to get FDA approval. Rockley is currently in the process of gaining FDA approval for its platform.

What this means for you and me

Rockley’s sensor technology and platform aren’t science fiction. It’s all coming very soon, and although it’ll initially be available through a dedicated medical technology company, that could change in the not too distant future.

“We launch the first device in the fourth quarter this year,” Rickman confirmed. “It’s a wearable designed for the professional health care market, and we have announced our first customer, Medtronic, which is the world’s largest manufacturer of medical devices.”

However, it’s what’s coming after that we’re most interested in.

Heart rate on the Apple Watch Series 7.
Andy Boxall / Digital Trends

“We are working with six out of the top 10 wearable consumer tech companies in the world,” Rickman continued, “and we’re working on designs to find a way to fit [the sensor] into their wearable devices. We haven’t announced a volume contract with any of them yet. We’re hopefully likely to make some announcement about it at the end of this year.”

It’ll be a bit like a fitness tracker, but a million times more powerful

In a 2021 SEC filing, Rickman mentioned several consumer electronics brands known for smartphones as being interested in the sensor technology. The document also mentions a “long-standing development and supply agreement,” with a company that had already invested $70 million with Rockley. Numerous reports have claimed Apple has invested a total of $70 million in Rockley for research and development since 2017.

Whether the Rockley Photonics platform eventually makes it to an Apple Watch, at least in some form, is unknown, but the convergence of consumer health tracking and medical health tracking is clear. Rockley’s platform could add functionality previously only available through doctors, clinics, and using blood tests, to a normal consumer wearable. In Rickman’s mind, it’s not that far away, and like Movano’s Stacy Salvi said in a recent Digital Trends interview, its arrival may change what the traditional consumer wearable looks like in the process.

“The type of wearable we’re producing for Medtronic doesn’t have a screen, it doesn’t tell you what your emails are. It’s purely dedicated to this rich functionality,” Rickman concluded. “It sits in the background just doing its job, but it still has a strap that can be changed and it’s easily cleaned. Maybe that evolves into a consumer device. It’ll be a bit like a fitness tracker, but a million times more powerful, in a format that will just sit in the background monitoring health. It’s another way of thinking about how it may arrive in the hands of consumers.”

Andy Boxall
Andy is a Senior Writer at Digital Trends, where he concentrates on mobile technology, a subject he has written about for…
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