Philips Expression MR400 - Identifying the Placement Site for the Quadtrode Electrode

ExpressionMR400InstructionsforUseMonitoringECG5‐7
Identifying the Placement Site for the Quadtrode Electrode
Warning
WAR NIN G
Ensure that the location of the electrodes is compliant to the requirements of your
electrosurgical equipment to reduce the possibility of burns; however, note that monitoring
in the MR environment requires specific electrode placement. (See page 5-3 to ensure the
highest quality ECG signal. For questions and guidance regarding placement, contact
technical support; see page 14-16 for contact information.)
Accordingtothepatienttypeorweight,placementoftheQuadtrodeelectrodeovertheheartis
importantforoptimalECGperformance.
Note
For placement purposes, we define to the breast line as an imaginary horizontal line that extends
across the nipple areas of a patient of normal weight.
Adultandpediatricpatients:
•IfusingastandardQuadtrodeelectrode,placeitslightlytotheleftofthepatient’s
sternum,withthetoptwoelectrodesonthebreastlineandthebottomtwoelectrodes
belowthebreastline.
•IfusingaCVQuadtrodeelectrode,attempttokeepasmallseparation
betweenindividual
electrodes—adistancethatiswideenoughtoproperlycapturetheECGvector,butnotso
wideastocauseexcessivenoisepickup.(Increasingtheloopareabetweenelectrodeshas
anegativeeffectonECGqualityuniquetotheMRIenvironmentthatcausesmorenoiseto
bepickedupby
theECGleads).
Neonatalandinfantpatients:
• Dependingonthepatient’sweight,centerastandardQuadtrodeelectrodeoraneonate
Quadtrodeelectrodeoverthesternumandthebreastline.
DeviationsfromtheguidelinesforQuadtrodeelectrodeplacementcanaffecttheproducedECG
signalasfollows:
• Placementsoffsetabovethebreastline:
IncreasestheT‐waveamplitudeandthe
susceptibilitytostaticfield(B0)effects.
• Placementsoffsetbelowthebreastline:DecreasestheT‐waveamplitude,increasethe
distancefromtheaorticvalve,thesusceptibilitytostaticfield(B0)effectsandtheECG
waveamplitude.
• Placementsclosertothesternum:Increasesthe
ECGwaveamplitudeandalsoany
respiration‐inducednoise.
• Placementsfartherfromthesternum:DecreasestheECGwaveamplitudeandany
respiration‐inducednoise.