Kathryn Clark鈥檚 epilepsy had been under control for years. Then, in November 2014, she was hit by a 鈥� the kind that spreads to the entire brain and leaves the victim convulsing on the floor.
鈥淚 haven鈥檛 had too many of those in my life, and that one was out of the blue,鈥� Kathryn says (pictured above). She was worried about looking after her children, then aged 2 and 4, if the seizures were coming back.
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Her husband Ryan, an , had an idea: program a smartwatch to detect movement characteristic of a seizure and text him a warning.
鈥淚 realized it should be possible, and took a week off work to throw this thing together,鈥� Ryan says. Now the pair have created software that does just that, and made it freely available online.
Motion detector
Devices that detect seizures are not new 鈥� researchers have tested sweat-sensing wristbands that can detect seizures via electrical currents travelling across the skin 鈥� but Ryan and Kathryn鈥檚 detection system has an advantage. Ryan chose to work with the $100 , one of the cheapest smartwatches on the market.
This means the program, called , is instantly available to any of the who might be living with epilepsy, with no need to buy anything else.
The Pebble has an accelerometer that can detect the wearer鈥檚 motion, so Ryan wrote code to spot rhythmic movements in the frequency range seen during tonic-clonic seizures. He figured out what that range was by watching and mimicking their motions while wearing the watch. He then compared the results against scientific literature.
If the watch detects motions that go above a certain threshold, it sends an alarm to the wearer鈥檚 phone. The wearer has 15 seconds to turn the alarm off if they are not having a seizure.
Panic button
鈥淭here definitely are false positives,鈥� Ryan says. 鈥淏rushing your teeth is almost exactly the same frequency and strength as having a seizure, it will definitely pick that up.鈥�
He warns that it can also miss real seizures if the arm wearing the watch gets trapped under the person鈥檚 body, for instance. 鈥淚t鈥檚 not foolproof,鈥� says Ryan. 鈥淚t shouldn鈥檛 be relied upon, but makes it more likely that a seizure will be detected.鈥�
If the alarm is not cancelled, the app automatically sends a text to predetermined numbers 鈥� in Kathryn鈥檚 case, Ryan and her dad. The text includes the wearer鈥檚 last known GPS location so the recipient can come and help.
The app also has a 鈥減anic鈥� button. If the wearer feels a seizure coming on, they can press it to warn their contacts. It is the only function Kathryn has had to use in the past year 鈥� although thankfully she hasn鈥檛 had any more tonic-clonic seizures.
Freedom/Safety
鈥淭hings are under control now, but we know that they might not always be,鈥� she says. She has shared the software with contacts at the in Vancouver, where she used to work as a counsellor for people with epilepsy. 鈥淗opefully they鈥檝e had a chance to tell some other neurology specialists about it. We just want to get the word out and let people know it鈥檚 available.鈥�
The Clarks say the watch has given them an increased sense of security and peace of mind.
鈥淢ost people with epilepsy and other chronic conditions will tell you it鈥檚 always a struggle to balance freedom with safety, independence with responsibility,鈥� Kathryn says. 鈥淥nce you get over the shock that you have seizures, you do have to get down to, OK, how am I going to live with them? This has been the answer in a lot of ways for us.鈥�
(Image: Ryan Clark)
