As sad as it may be, it seems from the README that the author was testing it on his wife, who suffers from those seizures.
Google returns several papers about detecting seizures with wearable accelerometers, but I haven't been able to find an openly available dataset. It would be great if there was one.
You are correct. I am aware of no public data set. I test it by watching YouTube videos (people often post videos of their seizures) and attempting to mimick the arm motions I see. Crude, for sure, but it's the best I can do.
Google returns several papers about detecting seizures with wearable accelerometers, but I haven't been able to find an openly available dataset. It would be great if there was one.