A new bracelet should reduce the number of nocturnal deaths in epilepsy patients. The bracelet monitors the movements and heartbeat of epilepsy patients. If a serious seizure is detected, it alerts a carer or nurse, who can thereby provide timely assistance.
'Sudden unexpected death in epilepsy' (SUDEP) is a leading cause of death in epilepsy patients. This term is used for the sudden death of a patient, where no cause of death can be established and there are signs of a recent epileptic seizure. Of the approximately 120,000 epilepsy patients in the Netherlands, some 10,000 have a mental disability or untreatable epilepsy. This group is at 20% risk of ever dying from SUDEP.
Many seizures are overlooked
Methods have long been available to monitor epilepsy patients at night, with the aim of detecting nocturnal seizures in time. However, many seizures are overlooked. To accurately detect nocturnal seizures, scientists from the Dutch Tele-epilepsy Consortium have developed a bracelet called Nightwatch.
Nightwatch is worn by epilepsy patients during the night. In doing so, the bracelet looks for features of severe epileptic seizures by monitoring patients' heart rate and movements. Plethysmography - an optical technique that uses light signals to measure volumetric changes in blood flow - is used to detect abnormalities in patients' heart rate. An accelerometer is used to map movements.
Alerting parents, carers or caregivers
Nightwatch can be used in a variety of situations. For example, parents or caregivers can use the bracelet to monitor a child with epilepsy during the night. This allows them to provide faster help in case of seizures and reduce the risk of medical complications. In addition, the consortium aims to use the Nightwatch to help epilepsy patients live more independently. By linking the bracelet with call system, if a nighttime seizure is detected, the Nightwatch can automatically alert emergency workers remotely.
However, the Tele-epilepsy Consortium is also targeting the healthcare sector with the Nightwatch. For instance, healthcare organisations can use the bracelet to automatically detect patients' nocturnal seizures and relieve caregivers. In addition, by detecting seizures earlier, they can intervene faster and improve the quality of care.
85% of seizures are detected
To evaluate how Nightwatch works, the consortium conducted a study in which 28 epilepsy patients with intellectual disabilities wore the bracelet. On average, participants wore the bracelet for a period of 65 days. In this, the bracelet was specifically configured to trigger an alarm signal only in severe seizures. To check the functioning of Nightwatch, participants were also monitored using video cameras.
The study shows that 85% of all severe seizures are detected by Nightwatch. For comparison, a bedside sensor that detects seizures by vibration was deployed simultaneously during the study. This sensor detected 21% of seizures during the study.
'Nightwatch could save tens of thousands of lives'
Prof Johan Arends, a neurologist at Kempenhaeghe and professor at TU Eindhoven, expects Nightwatch to reduce the number of SUDEP cases by two-thirds. Arends does note, however, that this largely depends on how quickly and adequately caregivers or informal carers respond to alarms. If Nightwatch is implemented worldwide, Arends says the bracelet could save tens of thousands of lives.
Currently, Nightwatch consists of two sensors: a heart rate sensor and a motion sensor. Both sensors generate alarms separately. The consortium is exploring the possibility of making the sensors work together on smart to further improve the accuracy of alarm notifications. It is also working on alarms based on sound and video, aiming to combine this detection method with Nightwatch. Finally, the consortium announces plans to make the interpretation of signals patient-specific in the future.
Available through LivAssured
The Nightwatch is being marketed in the Netherlands by LivAssured. This company was founded specifically to market the bracelet and has been involved in the development of Nightwatch since 2014.
Author: Wouter Hoeffnagel
Source: TU/e
Source: LivAssured
