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False Leg Signals

PostPosted: Tue Apr 15, 2014 1:55 am
by tudorman
I've been having a problem that comes & goes, in both rooms, for a few months. Sometimes with heavy snoring the chin EMG and the Leg EMG's will indicate activity. The filter settings haven't been changed and I'm not doing anything differently. What is making the snoring "bleed over" to these other channels? I'm using Alice 6.

Now I'm going to start on my taxes; they're due pretty soon, right?

PostPosted: Wed Apr 16, 2014 6:35 am
by MrBig
The last lab I was at had upgraded to Alice6, a few of the head boxes had to be sent back because of weird artifact. We tried just about everything to see what it was, prior to sending the head boxes back.

PostPosted: Fri Apr 18, 2014 6:56 pm
by linuxgeek
I think this is usually due to the leg leads going over the chest or neck. I think it's probably due to the mechanical vibration of the wire.

PostPosted: Fri Apr 18, 2014 6:57 pm
by linuxgeek
I should add, that I think that's mostly for the leg. The chin EMG can be a little different cause it is anatomically really close to the vibration.

Re: False Leg Signals

PostPosted: Thu May 08, 2014 10:06 am
by Narco
tudorman wrote:I've been having a problem that comes & goes, in both rooms, for a few months. Sometimes with heavy snoring the chin EMG and the Leg EMG's will indicate activity. The filter settings haven't been changed and I'm not doing anything differently. What is making the snoring "bleed over" to these other channels? I'm using Alice 6.

Now I'm going to start on my taxes; they're due pretty soon, right?


Hey Tudorman,

Had that same problem. EMG channels not working properly. Head box was changed twice already and still waiting for replacement. it is really frustrating!
If only I had a choice... but its not my call.

Narco

Re: False Leg Signals

PostPosted: Thu Mar 12, 2015 8:36 pm
by Rocklandish
We are having this same issue with the new Sandman upgrade. The artifact shows up in the legs and ECG channels.