Scientists in the Netherlands have developed a new high-tech bracelet which they say could significantly reduce the number of unexpected nighttime fatalities in epilepsy patients.
The Nightwatch device is worn around the upper arm at night and measures heart rate by plethysmography and movement 3-dimensional accelerometry.
Researchers prospectively tested the bracelet among 28 participants with epilepsy and intellectual disability in a residential setting for between two and three months, and compared it to the current standard, a bed sensor. The patients were also filmed to check if there were any false alarms or attacks that the Nightwatch might have missed.
During a total of 1,826 observed nights, 809 major seizures and 2,040 alarms occurred. Median sensitivity per participant was 86 per cent (95% CI 77%-93%). The false-negative alarm rate was 0.03 per night (95% CI 0.01-0.05) and the positive predictive value was 49 per cent (95% CI 33%-64%). Tonic-clonic seizures were particularly well detected by the multimodal sensor. The sensitivity of the bed sensor (median 21%; 95% CI 6-32%) was significantly lower than that of the multimodal sensor.
Presenting the findings in Neurology, the authors said the new device may be of help in preventing sudden unexpected death in epilepsy.