Image: The Embrace smart watch can identify convulsive epileptic seizures (Photo courtesy of Empatica).
A novel watch uses advanced machine learning to identify convulsive seizures and send alerts to caregivers.
The Empatica (Cambridge, MA, USA) Embrace device is based on detection of electrodermal activity (EDA), which quantifies physiological changes related to the human sympathetic nervous system. Embrace also includes a gyroscope to measure rotational speed, a 3-axis accelerometer for high sensitivity motion detection, and a peripheral temperature sensor. The device continuously monitors the wearer for grand mal or generalized tonic-clonic seizures, and transmits the data to a paired smartphone via Bluetooth.
From the smartphone, the data is sent to Empatica’s secure servers via Wi-Fi. Alerts warning of abnormal activity are then sent to caregivers through text and phone. The smart monitoring watch also tracks sleep, stress, and physical activity. In a multi-site clinical study, 135 patients admitted to an epilepsy monitoring unit (EMU) were simultaneously observed via video electroencepholagraphy (EEG) and the Empatica device. In all, 6,530 hours of data were recorded, including 40 generalized tonic-clonic seizures. The Embrace algorithm was shown to detect 100% of the seizures.
“It's been quite the journey, we have worked for years building wearable stress and emotion sensors, and then accidentally discovered we could pick up changes in the skin elicited by brain activity related to the most dangerous kinds of seizures,” said Rosalind Picard, PhD, director of the affective computing group at the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA), and Chief Scientist at Empatica. “It has been very meaningful to see this technology move from the lab into the most accurate, beautiful and easy to use sensor on the market.”
“Medical devices face a huge problem: they're usually too bulky and uncomfortable, and people simply don't want to wear them. Empatica took a different path; we wanted to design the world's first medical device that could win a design award, while being used as a lifesaving product,” said Matteo Lai, co-Founder and CEO of Empatica. “Patients actually love Embrace and are proud to wear it. We think this has been one of the keys of its success and an interesting lesson for healthcare. Cutting edge technology and good design need to go together.”
Sympathetic system activation increases with stressors, whether physical, emotional, or cognitive. In some medical conditions, including epilepsy, it shows significant increases that are related to specific brain structures activation. As the skin is the only organ purely innervated by the sympathetic nervous system, and not affected by parasympathetic activation, monitoring subtle electrical changes across the surface of the skin can detect increases in sympathetic activation.
Massachusetts Institute of Technology