Question 17

Explain the following components of an electrocardiogram (ECG) machine; electrodes, leads, amplifiers and filters. (70% of Marks) Outline methods employed to reduce artefact. (30% of Marks)

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College Answer

Good answers described electrode components, intensity of signals measured (requirement for and levels of amplification), lead position and differences between unipolar and bipolar leads. Rationale and mechanisms of filtering were less well described. Description of highand low-pass filtering along with detail on monitoring and diagnostic modes scored marks. Patient-related, electrical and environmental methods of reducing artefact attracted marks.