OK, I almost banned that guy (thought it was sort of Chinese spam bot), so, as some kind of moral "excuses", I'll translate what he got in mind:

OP seems to think about some kind of incoming-earthquake alarm. He noticed, that sleep analyzer is able to detect very small movements of sleeping person - so, OP think that N900 would be able to detect very small vibrations, that occur seconds or - in some cases - minutes, before earthquakes (and warn user).

Personally, I think this isn't good idea - you would probably get alarm everytime truck pass road next to Your house (or someone is running upstairs), but, it was just in sake of explaining mess, that his auto-translator created.

/Estel