Beta Release of OpenSeizureDetector V2.5.1

I have just released a new Beta test release of OpenSeizureDetector on Google Play Store (V2.5.1).

The only change is an improvement to handling alarms from short duration seizures.   If a seizure is only detected for a short period, the previous version may only give a single set of Alarm beeps, which may be insufficient to alert a carer.

With the new version, if you enable “Latch Alarms” in the Alarms settings then when an alarm initiates, the alarm beeps will sound for the period specified in the “Latch Alarm Timer Duration” setting, even if the alarm resets quicker.

You can stop the alarm to silence the beeps earlier by pressing the Accept Alarm button.  This works both on the main OpenSeizureDetector app screen, and also if you are running it on another device using Network Datasource to provide alarm annunciation in a different part of the house.

This is as a result of the seizure Benjamin had last week, when we only got a single sent of alarm beeps.   This is fine if you are awake and alert, but if you are asleep it may not be enough to rouse you.   More details of this event on the Real Test of OpenSeizureDetector page.    A further update will follow fairly soon with an improved algorithm to detect seizures with lower frequency movement.

Update to Beta Version

I have just published an update to the Beta test version of OpenSeizureDetector (now V2.3.1).   This fixes two issues reported by testers:

  • The detection was much more sensitive than previous version, so the default Alarm Ratio Threshold setting has been increased to 50 (we use 56 for Benjamin because he is quite bouncy), so you may need a higher value, but I don’t want to make it too insensitive.
  • The auto-start on boot feature now works with the phone screen locked.

This release will be available to anyone who has registered as a beta tester here in the next couple of hours.

OpenSeizureDetector V2.0.8 Released

A quick bug-fix beta release (Thank you Damian for reporting it!) – if you have an incompatible version of the watch app installed it will now pop up a friendly-ish message asking you to upgrade the watch app, rather than crashing with an obscure error.

Available on for beta testing here:

Sorry for the inconvenience again!

Problems with Pebble Classic

Please note that the OpenSeizureDetector set-up that I have for my son developed a problem today and the watch app stopped talking to the phone (so the phone just gives those annoying fault ‘pips’).   I do not know what has caused the problem, but I suspect that it is to do with an update to the Pebble software.
Therefore I would recommend that if you are given the option to upgrade the Pebble Software you do not upgrade it for the time being, until I work out what is wrong with mine and confirm that the upgrade will be ok for you.
Note that I have another system that is using a Pebble Time rather than the older Pebble Classic – the Pebble Time one is working ok, but my two Pebble Classics are not.

Beta Release of Version 2.0.4 of OpenSeizureDetector

Screenshot_2016-05-14-22-34-49I have just publshed a beta test release of OpenSeizureDetector V2.0.4.  Changes are:

– Improved handling of watch app settings.
– Changed default AlarmFrequencyMin setting to improve detection reliability.
– Install watch app directly from phone rather than using pebble store.
– Main screen graph now a bar chart showing frequency
region of interest.

Opt-in to beta testing here, then it will install from Google Play Store.

As usual, any comments or feedback to, or facebook please!

Use of AngelSensor as a Seizure Detector

I have just bought an Angel Sensor M1 wristband to try it out as an alternative seizure detector to the Pebble.

The OpenSeizureDetector Android App is written to allow extra ‘data sources’ to be used, so I will have a go at writing a DataSorurce that uses the angel sensor instead of the pebble.   The first effort will be to repeat the same functionality as you get with the Pebble, then extend it to use the other sensors such as skin conductivity and heart rate.   This should reduce the number of false alarms compared to the Pebble…If I can make it work!

Initial findings:

  • The Open Source Angel Sensor Android app installed ok and said it was scanning looking for the device.
  • The instructions ( said press the button on the device to switch it on – it was hard to see the button – there is a hard plastic blister on the top, but it doesn’t move when you squeeze it.   Started to think the device is dead…..
  • Tried plugging it into the charger – the LEDs in the device came on, which is a good sign, but nothing else.
  • Waited a while…..
  • Now squeezing the plastic blister on the device makes it vibrate a bit – I think long and short presses do different things….
  • After a few presses must have managed to switch it on and the phone app connected to it – phone app displaying temperature and has placeholders for other parameters such as steps and heart rate, but they are not displaying values….  Display says battery is


Release of OpenSeizureDetector V2.0

pebble_screenshot_2016-02-17_21-41-11I have finally fixed the last few bugs (that I know about), and have Released V2.0 of the OpenSeizureDetector Pebble Watch App and Android App.

There are a lot of ‘behind the scenes’ changes to the Android App to make the code easier to maintain in the future.  From a user’s perspective, the changes yopebble_screenshot_2016-02-17_21-41-54u will see are:

  • You can mute the alarms using the top watch button (long press).
  • You can manually initiate an alarm using the bottom watch button (long press).
  • The system should be easier to install from scratch because it will prompt you to install the Pebble Android App and the OpenSeizureDetector watch app if they are not installed.
  • There is a new start-up screen that shows which bits of the system are working – this will help with fault diagnosis as the main screen is not displayed until everything is ok.
  • The main screen has two graphs that show how far the system is off alarming – when both bars get to the right and side and turn red, it alarms.
  • The system settings have been organised into different screens to make it easier to find things.
  • The ‘general’ settings allow the user to select a ‘datasource’  this is either ‘Pebble’, in which case the system talks to the pebble directly, or ‘network’, in which case it will receive data from another device running OpenSeizureDetector – this is useful to extend the range of alarms to other parts of the house (this is what the OpenSeizureDetector Client app does – so the client app is now redundant).

Although I have fixed a lot of bugs in this release, the changes have been so significant that I am bound to have introduced new issues – please feed back any issues you have – ideally to the Facebook page I have set up so others can see it, otherwise email me (

Detection Algorithm Comparison

I have been thinking about seizure detection algorithms.   The one I use for the OpenSeizureDetector Pebble watch looks for movement in the range 5-10 Hz, which seems to work for the high frequency jerky type of movements that I associate with a tonic-clonic seizure.   Although they have not published their algorithm, this seems similar to the Neutun app detection method.  Ryan Clark’s PebbleSeizureDetect uses a band pass filter to select a 1-3 Hz range, which is a much slower movement.     I am sure he has found that this works for the sort of seizures he is trying to detect.

I have made a couple of videos showing the sort of movement that the two algorithms detect – the watch on the left is running OpenSeizureDetector, and the one on the right PebbleSeizureDetect – you can hear the buzz when PebbleSeizureDetect alarms, or see the ‘WARNING’ or ‘ALARM’ phrase on the OpenSeizureDetector screen.

My concern is that the two algorithms are quite different – a seizure that alarms with OpenSeizureDetector will not trigger PebbleSeizureDetect.   I am pretty happy with the OpenSeizureDetector one – I have had some positive reports of it detecting seizures ok, and the movement it detects is consistent with some of the movement you can find on some slightly disturbing YouTube videos of people having seizures,  But Ryan developed his to work for his application…so which one is best to give the highest detection reliability?

Any thoughts would be appreciated – please either email or use the Facebook OpenSeizureDetector page.

Video 1 – shows the ‘borderline’ movement that just alarms OpenSeizureDetector – first a few intermittent ‘WARNING’ alarms, then with a slightly higher amplitude movement, goes into ‘ALARM’ – PebbleSeizureDetect does not respond.

Video 2 – lower frequency movement that alarms PebbleSeizureDetect (about 25 seconds in), but not OpenSeizureDetector – demonstration of the higher frequency movement that alarms OpenSeizureDetector at the end of the video.