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.