factors aff ecting ecg trace quality · factors aff ecting ecg trace quality factors aff ecting ecg...
TRANSCRIPT
Factors aff ecting ECG trace quality
Factors aff ecting ECG trace quality
Monitor Skin
Environment
Electrode
Cables & lead wires
� CMRR (Common Mode Rejection Ratio) used to separate ECG from other signals
� Filters
� Bandwidth (frequency response)
� Amplifi er noise
� Ground loops
� Saturation distortion (e.g. defi brillation recovery)
� Input impedance
� Diff erential input (required to generate ECG tracing)
� Impedance
� Diaphoresis
� Dryness
� Oiliness
� EMG, respiration and other biopotentials (physiological electrical signals)
� Skin preparation techniques
� Obesity
� Skin stretch
� Motion artifact
� Adhesion
� Conductor
� Gel
� Backing
� Size
� Design
� Motion
� Shelf life
� Application technique
� Electrical/mechanical properties
� Location on the body
� Electrical fi eld (60 Hz)
� Humidity
� Temperature
� Static electricity
� Magnetic fi eld
� Radiofrequency
� Vicinity of other machines
(nebulizers, fans, power cords, etc.)
� Mechanical/electrical properties of materials
� Shielded cable and shielded lead wires
� Open lead wires (avoid loops)
� Triboelectric eff ect (generated by cable movement)
3M Ireland LimitedThe Iveagh BuildingThe Park, CarrickminesD18 X015Ireland+353 (0)1 280 35553M.ie/RedDot
3M United Kingdom PLCCharnwood Campus10 Bakewell RoadLoughboroughLE11 5RB01509 6116113M.co.uk/RedDot
3M and Red Dot are trademarks of 3M. © 3M 2018. All Rights Reserved.
ECG electrode placement
Artifacts SkinImpedance
MuscleMovement
ElectricalContinuity Electrodes Cabling Interference Equipment
No Base Line2
Check allconnections/
performcontinuity check
4Check for dry-out
3Check for
proper cable
1Check lead switchand ECG machine
set-up
Base Line Wander 3Abrade skin
1Stop patientmovement
2Check groundconnections
4Use same type of
electrode at all sites
6Check for
proper cable
5Check for static
build-up
AC Noise3
Abrade skin6
May be untreatable
involuntary muscletremor
1Check groundconnections
5Check for dry-out
7May need fully
shielded cable andlead wires
2Keep cable away
from AC cord
4Turn off
fl uorescentlights and/or other
equipment
Intermittent Signal 1Check for loose
connections
2Check for loose
electrode or dry-out
4Perform continuity
check
3Check for static
build-up
Motion Artifact2
Abrade skin1
Move electrodes off muscle mass
3Check for loose
connections
4Check for loose
electrode or dry-out
7Perform continuity
check
5Turn off
fl uorescentlights and/or other
equipment
6Check for proper
EKG machine set-up
Low Amplitude3
Abrade skin1
Check allconnections
4Check for dry-out
5Turn off radio,
TV and/or other equipment
2Check gain
settings
Troubleshooting ECG tracesTroubleshoot each artifact in order, starting with 1
3-Lead PlacementMonitoring Electrodes
5-Lead PlacementMonitoring Electrodes
RA LA
LLRL
V2V2
Monitoring ElectrodesMonitoring Electrodes12-Lead Placement
Resting Electrodes
RA
LLRL
V1 V2
V3V5 V6
V2V2LA
V4
RALA
LLRA: Second intercostal space lateral right sideLA: Second intercostal space lateral left sideLL: Lower left lateral chest or left legRL: Lower right lateral chest or right legV2: Fourth intercostal space to the left of
the sternum
RA: Second intercostal space lateral right sideLA: Second intercostal space lateral left sideLL: Lower left lateral chest or left leg
RA: Second intercostal space lateral right sideLA: Second intercostal space lateral left sideLL: Lower left lateral chest or left legRL: Lower right lateral chest or right legV1: Fourth intercostal space to the right of the sternum
V2: Fourth intercostal space to the left of the sternumV3: Between V2 and V4V4: Fifth intercostal space along the mid-clavicular lineV5: Fifth intercostal space between V4 and V6V6: Fifth intercostal space along the mid-axillary line