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Chapter 8
MONITORING PARAMETER
8.1 ECG Monitoring
8.1.1 How to Obtain High Quality ECG and Accurate Heart Rate Value
The electrocardiogram (ECG or EKG) is primarily a tool for evaluating the electrical events within the heart. The
action potentials of cardiac-muscle cells can be viewed as batteries that cause charge to move throughout
the body fluids.
These currents represent the sum of the action potentials occurring simultaneously in many individual cells
and can be detected by recording electrodes at the surface of the skin. The figure below shows the system of
the heart.
First of all, the hospital should be equipped with a 100~240V power supply system with a typical grounding
wire. If big interference in ECG continues, connect one end of the grounding wire provided with this equipment
to the grounding wire on the back panel of this Gima Vital Signs Monitor, and the other end to the special
grounding wire, water pipe or radiator.
A common ECG plate electrode used together with this monitor has short shelf life. Generally, the shelf life is
only one month after the package is opened. When outdated plate electrode is used, due to skin’s contact
impedance and big electrode potential, the chance of interference will be increased, and the ECG baseline will
have an unstable inclination.
Therefore, always use valid plate electrodes.
8.1.2 Factors affecting ECG signal
• Interference from Electrosurgical Unit;
• Doesn’t filter the interference waveform;
• Poor grounding;
• Electrodes are not placed properly;
• Use expired electrode or use disposable electrode repeatedly;
• The skin placed electrode is unclean or poor contract caused by scurf and hair;
• Electrode long-time used.
HIS Bundle
Left Bundle Branch (LBF)
Left Posterior Fascicle
(LPS)
Left Anterior
Fascicle (LAF)
Left Ventricle
Left atrium
Purkinje Fibers (PF)
Atrioventricular Node
(AVN)
Right Bundle
Branch
(RBB)
Right atrium
Right Ventricle
Cardiac Conduction System
Sinoatrial Node
(SAN)