Wearable seizure detector as consumer product

photosensitive epilepsy, smart computing

The Embrace watch doesn’t look like a medical device, but its sensor technology has been used in research published in leading neurology journals. Photo credit: Empatica

Later this year parents will be able to monitor a child’s seizure activity by using wearable technology in the form of a sleek, stylish watch with sensors underneath. The $199 Embrace watch, which will debut in October, could eventually offer a way for parents to learn whether the video games their child is playing are triggering seizures.

The Embrace won’t be able to do a thorough job of that yet—primarily because the device is currently most accurate for detecting tonic-clonic (grand mal, convulsive) seizures. Many seizures aren’t that type; they’re complex or absence, so the device would need to reliably pick up all seizure types. In addition, the Embrace hasn’t been tested specifically for picking up seizures triggered by visual stimuli. In its initial release, though, Embrace will be able to alert parents to tonic-clonic seizures while their child is asleep or in another room.

Most seizure detection devices (except EEG) rely on motion sensors that transmit an alert to a caregiver about a convulsive seizure. The Embrace wristband works primarily by detecting subtle changes in the flow of electrical charges on the skin. These changes in skin conductance are reliable indicators of changes in deep-seated areas of the brain associated with seizures, the hippocampus and amygdala. In times of cognitive, physical, or emotional arousal—and during seizures, these parts of the brain are activated. In some instances, changes on the skin can even be detected prior to the onset of a seizure.

As I’ve noted elsewhere, although EEG is the gold standard used by doctors to diagnose seizures, it’s limited in what it can pick up from structures deep inside brain. EEG uses scalp electrodes to detect electrical signals that first must penetrate the outer brain layers (cortex) and the skull. Because electrodes are affixed to the other side of these layers of tissue and bone, not all seizure signals can be detected at the surface.

The Embrace sensor technology was initially developed by the MIT Media Lab to help people on the autism spectrum to identify and communicate their stress level. The MIT team subsequently discovered that the sensors could detect not only stress/arousal levels but also seizures, including some seizures not picked up on an EEG. A start-up was formed, Empatica, to bring the wearables to market with the help of Indiegogo crowdfunding. I’m intrigued by the company’s roots in technology to aid people with autism; the autism community is probably at highest risk for photosensitive epilepsy and would therefore significantly benefit by being able to identify visually triggered seizure activity.

Sensors on the underside track skin conductance and body movement. Credit: Empatica

Sensors on the underside track skin conductance and body movement. Photo credit: Empatica

If your child is fatigued and kind of “out of it” at the end of a gaming session, imagine being able to find out whether hidden seizures are occurring during certain games. Wouldn’t it be great to be able to correlate seizure activity with specific video games? I’d love to see this application of the Embrace watch come about.

A video about Embrace is available on Empatica’s Indiegogo page.



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