FDA clears seizure-detecting wearable for epilepsy patients

The FDA has approved (PDF) Empatica’s seizure-detecting wearable for use by epilepsy patients. Empatica picked up the 510(k) clearance for Embrace after the device detected every seizure in a 135-patient clinical trial.

Embrace looks like other smartwatches and activity trackers and shares some of their features. The key difference is Embrace pairs its gyroscope, accelerometer and thermometer with an electrodermal activity (EDA) sensor and an algorithm that analyzes the data stream for signs the wearer is suffering a seizure. EDA indicates whether a person is in “fight or flight” mode.

The result is a device and accompanying algorithm that detected every seizure in a 135-patient trial. Empatica demonstrated the accuracy of Embrace by comparing its readout with the opinions of two to three epilepsy experts who had access to video-EEG data but not the results from the wearable. That trial took place in an epilepsy monitoring unit but Empatica has also generated data showing the device detects most seizures when worn by patients in real-world settings. 

Embrace detected different types of seizures across the trials, including generalized tonic-clonic seizures. Such seizures cause loss of consciousness and can leave patients confused. This results in the underreporting of the seizures in patient diaries. Embrace’s ability to more accurately detect these events could make it a useful tool for sponsors of epilepsy clinical trials.

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The ability of the device to send alerts to caregivers also makes it potentially helpful in the real world. But there is also a risk the device will cause more stress than it alleviates if it triggers false alarms. Empatica has worked to cut the rate of false positives but they still happen. In the 135-person trial, patients experienced one false alarm every two days on average. The rates seen in other studies have been both a little higher and a little lower.

Empatica is betting that is a manageable downside given the potential upsides of the device.

“Tragically, more than 3,000 Americans die each year from sudden unexpected death in epilepsy and the Embrace offers the potential to alarm family members and caretakers that a tonic-clonic seizure is occurring. The scientific evidence strongly supports that prompt attention during or shortly after these convulsive seizures can be life-saving in many cases,” Orrin Devinsky, M.D., director of the Comprehensive Epilepsy Center at NYU, said in a statement.

MIT Media Lab spin-off Empatica is charging $249 for the device and between $9.90 and $44.90 a month for subscriptions that connect to caregivers and provide other features.