The Pebble Smart Watch seizure detector measures movement of the arm using the accelerometers in the watch. An Android Server application runs on a device that is kept close to the watch (<~5m away). This provides a status display and raises audible alarms. It also provides a web based interface for other clients to connect to to raise alarms at a remote location.
The Watch App that runs on the Pebble watch measures the accelerometer readings and analyses the frequency of movement. It raises an alarm if the movement within a given frequency range is high enough for a period of 15-20 seconds (see screenshot image on right). There is a bit more detail on the detection algorithm here.
The watch app sends regular status updates to the Android Server App, which runs on a mobile phone connected to the Pebble watch using its Bluetooth radio.
Android Server Application
The Android Server App that runs on an Android phone receives data from the watch and provides a simple display of the alarm status.
It sounds audible beeps if a fault, warning or alarm condition is detected.
It runs a web server that provides a simple web page that shows the frequency spectrum of the detected movement. The page will show the alarm status of the device and beep if a warning or alarm condition is initiated.
The server app can also be set to send an SMS text message containing a custom message to a list of telephone numbers when an alarm condition is activated.
The ‘Settings’ menu option allows the audible and SMS alarms to be switched on and off as required. The ‘Settings’ menu also allows the seizure detection algorithm parameters to be altered if required to change the sensitivity of the detection algorithm.
The web interface is accessible from any device (desktop computer, mobile phone, tablet).
It shows the overall alarm status (OK, WARNING or ALARM) and beeps on a warning or alarm condition as well as changing colour to give a visual indication of a problem. It includes graphs showing the frequency spectrum detected by the Pebble Watch.
Android Client Application
We have an Android Client Application that will run on most Android devices to monitor the seizure detector and alert the user if a seizure is detected by giving both an audible alarm and a visual signal.
The application runs in the background so will still work if you are using the device for something else.
A short video demonstration of the watch based seizure detector can be seen here.
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