Carmen, more an echo of Rob's comment and maybe little help to
     you but actually ultrasound transducers are fairly efficient
     RF receivers. My experience is with imagers primarily. Wave a
     transducer towards a flourescent light and the screen lights
     up. Interestingly enough, as a flourscent tube nears the end
     of its life, the effect is markedly pronounced. Over the
     years, we have had a number of occasions with offending lights
     and/ or instruments in the vicinity. Sometimes using a
     different outlet can help. No scientific basis for any of this
     but I have also noted that external RF interference is most
     pronounced in the near field whereas if the artifact or noise
     seems to come from the far field, I would suspect the
     instrument.

     Bill Schroedter




______________________________ Reply Separator _________________________________
Subject: Re: TCD MONITORING INTRA-OP
Author:  UVM Flownet <[log in to unmask]> at Internet
Date:    9/9/99 4:43 PM


Carmen, this reply is a bit off your question, but we had a gel-warmer in
our lab  few years back that was on the fritz and it was emitting an RF
noise that was causing big interference with our duplex scanner.  We
moved another duplex system into the exam room thinking the original one
had "gone south", and the noise appeared in the second system as well.
 Unplugging the gel warmer "repaired" both systems.
Rob Daigle

 -----Original Message-----
From: O'Brien, Carmen [mailto:[log in to unmask]]
Sent: Thursday, September 09, 1999 4:04 PM
To: Robd; UVMFLOWNET
Subject: TCD MONITORING INTRA-OP


This is a brief letter to inquire whether anyone one else who performes
TCD monitoring during intra-op CEA's experiece R/F interference.