Does anybody have a seizure alert service dog? If you do, how well do they help?

I have been having alot of seizures, they have been horrible. We have been trying to adjust my meds, but so far no luck. and 2 weeks ago i almost fell down a flight of steps if it wouldnt have been for someone to see me and catch me. So we are now considering getting a service dog, so even if the dog couldnt alert me, it could atleast get somebody for me or call 911. So i was just wondering if anybody has one and have they really helped you. Thanks!