For years, Patti Long worked as a surgical nurse, performing elective cosmetic operations for a clinic that served military veterans at no cost. Each procedure was painstakingly precise, requiring Long to remove hair follicles one at a time before she transplanted them to a recipient site, replacing follicles that had been irreparably damaged in combat.
But five years ago – aged 48 – Long found out she had to cut short her surgical career. As she got older, her epileptic seizures had worsened and become more unpredictable. “It was like someone slammed the door on my life,” she says. She had a support dog that would stay with her if she had a seizure, but other than that she was largely on her own.
But then Long heard about an experimental smartwatch, called Embrace. A medical-grade wearable that doesn’t look like a medical device, Embrace’s monochrome watch face and interchangeable straps make it look more like a fashion statement than a potential lifesaver, but that’s exactly what it is. By measuring subtle changes in sweat levels, it can detect when the person wearing it is having an epileptic seizure. When the device is triggered, the face glows red and sends an automated message and phone call to nominated caregivers.
“If I’m out gardening in the yard and it happens, I’ve woken up looking up at the sky and the next thing I see is the person that the device was called,” Long says. She has four nominated caregivers and every time they get an alert, they call her to check if she’s alright. If she doesn’t call back, they immediately visit or send someone over to make sure she’s okay.
Since Long has a form of epilepsy that triggers seizures that can stop her heart, it’s important that she receives help as soon as she has a seizure. “If I don’t get help, I’m in trouble,” she says. In the past, she’s ended up with a broken wrist and hand after falling during a seizure, and while wearing Embrace doesn’t necessarily mean that injuries won’t happen in the future, it does make Long feel more at ease and able to live more independently than she could without the device. “It really gave me a lot of confidence, and living alone it’s kind of a big deal if you have really serious seizures.”
The wearable, which has become the first smartwatch to be approved as a medical device in the US by the FDA in early February, works by measuring the skin’s electrodermal activity – an indicator of neural activity and stress. Embrace picks up the skin’s increase conductivity caused by the sweating that is associated with the onset of a tonic-clonic seizure. Embedded accelerometers and gyroscopes also tell the device whether the person is likely to have fallen or is making sudden movements, while a thermometer detects longer-term changes in skin temperature.
Before Embrace, there was just no way for people with epilepsy to reliably keep track of their seizures in their own homes. “Outside of the hospitals, doctors are relying on self-reports from patients,” says Empatica co-founder and CEO Matteo Lai. Most of those seizures go completely unrecorded because, by the time a person visits their neurologist, they may forget how many seizures they had or when they happened.
The Embrace wearable comes with an app that tracks seizures as well as sleep and activity levels so users and their neurologists can start identifying triggers or patterns. “We want patients to understand more about their behavior when seizures happen,” Lai says. Every month, Long shares her Embrace reports with her neurologist, and she says that the FDA approval now adds even more weight to the results. “It’s the first time I can say to her that this is an FDA-approved device,” she says. “That makes a big difference to them.”
In clinical trials for the device, 135 patients diagnosed with epilepsy were admitted to monitoring clinics where they wore video-EEG devices as well as an Embrace smartwatch. In over 6,530 hours of monitoring, the Embrace watches detected 100 percent of tonic-clonic seizures – exactly the same rate as the video-EEG devices, which can only be used for long-term monitoring if the patient is hospitalized. Embrace, on the other hand, is deliberately designed the watch so it looks like a stylish watch, not a medical device. If people don’t wear it, then it just won’t do the job, Lai says.
And since the initial launch of Empatica in 2016, after raising over $780,000 through a crowdfunding campaign in late 2014, Lai has been using data from users enrolled in clinical trials to refine the device. “The system really improved when we started having people using it all the time,” he says. Very early versions were much too sensitive and falsely identified as many as six seizures per day. Long, who bought the device soon after it was released, remember setting it off every time she brushed her hair. With training data from in-use devices, Lai and his colleagues were able to get the false alarm rate down to less than 0.15 per day.
For Lai, the ultimate goal is to build a device that’s capable of predicting when a seizure will happen. “We want to be able to understand their physiology and how that might lead to seizures,” he says. It might be the case that for some users, high-stress levels make it more likely they’re going to have a seizure. For others, a lack of sleep could be a trigger. In time, Lai would like to see future versions of the device that are able to learn about their user’s physiology and warn that person when they are at higher risk of a seizure.
“If the watch could predict when I was about to have a seizure, I could get to the floor before I had an injury,” says Long, who had just had some stitches removed from her hand after cutting herself during a seizure a few weeks before we spoke. If she’d been able to wear a smartwatch that could predict seizures as well as send alerts, she says that she might have been able to keep her job as a surgical nurse. “If that had happened sooner, I could have stayed in step with my career,” she says.
As well as exploring seizure forecasting, Lai is also working on using electrodermal activity sensors to help manage other conditions. Detecting a person’s stress response could be particularly useful for people with autistic spectrum disorders, he says, as it might be possible to build a device that warns people when their stress levels are about to become too high. He’s also researching whether wearables could help people with depression better manage their condition.
But for Long, the benefits of wearable medical devices are already here. After a year and a half with Embrace, it’s restored much of the confidence that she lost when she had to give up her job. “It’s so much more manageable than having a dog standing next to you,” she says. “I’m a completely different person today.”