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Factors affecting ECG trace quality Factors affecting 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) Amplifier noise Ground loops Saturation distortion (e.g. defibrillation recovery) Input impedance Differential 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 field (60 Hz) Humidity Temperature Static electricity Magnetic field 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 effect (generated by cable movement) 3M Ireland Limited The Iveagh Building The Park, Carrickmines D18 X015 Ireland +353 (0)1 280 3555 3M.ie/RedDot 3M United Kingdom PLC Charnwood Campus 10 Bakewell Road Loughborough LE11 5RB 01509 611611 3M.co.uk/RedDot 3M and Red Dot are trademarks of 3M. © 3M 2018. All Rights Reserved.

Factors aff ecting ECG trace quality · Factors aff ecting ECG trace quality Factors aff ecting ECG trace quality Monitor Skin Environment Electrode Cables & lead wires CMRR (Common

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Page 1: Factors aff ecting ECG trace quality · Factors aff ecting ECG trace quality Factors aff ecting ECG trace quality Monitor Skin Environment Electrode Cables & lead wires CMRR (Common

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.

Page 2: Factors aff ecting ECG trace quality · Factors aff ecting ECG trace quality Factors aff ecting ECG trace quality Monitor Skin Environment Electrode Cables & lead wires CMRR (Common

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