Why is conducting gel or a sticky electrode pad used in an ECG?

The gel lowers the electrical resistance between the skin and the electrode. The weak signal is then recorded clearly with little interference.

What is a Holter monitor?

A Holter monitor is a small portable ECG recorder worn for 24 hours or longer. The device catches irregular heartbeats that may not occur during a short hospital test.

An ECG shows R waves 0.8 s apart. What is the heart rate?

The heart rate is 75 beats per minute. The working is 60 ÷ 0.8 = 75.

How has ECG equipment improved patient monitoring?

Modern ECG machines give digital traces that can be stored, compared and sent to a specialist instantly. Bedside monitors also sound an alarm when a dangerous rhythm appears.

CCEA A-Level Life and Health Sciences 0008

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Enabling TechnologyDouble Award

Topic overview ECG and EEG machines in patient monitoring Ultrasound and IVF equipment in fertility treatment Prosthetic limbs, hearing aids and cochlear implants Workflow and equipment in a medical laboratory Ongoing monitoring of a long-term condition Health data collection, databases and data protection

Enabling Technology

ECG and EEG machines in patient monitoring

3 things to know
A2 10

Overview

How ECG machines and 12-lead ECGs work, Holter monitors and wearables, a heart rate from R waves, EEG machines and their uses in epilepsy and sleep studies, and improvements in workflow.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

How does an ECG machine detect the heart's activity, and what is a 12-lead ECG?

Key term

How does an ECG machine detect the heart's activity?

Key term

What is a 12-lead ECG?

Questions from this subtopic

Each one with the model answer underneath.

1
How does an ECG machine detect the heart's activity?
Model answer
Electrodes stuck to the skin pick up the tiny voltages produced as electrical impulses spread through the heart muscle. The machine amplifies these signals and records them as a trace.
2
What is a 12-lead ECG?
Model answer
A 12-lead ECG uses ten electrodes on the limbs and chest to view the heart's electrical activity from twelve angles. Damage to a particular region of the heart can then be located.
3
Why is conducting gel or a sticky electrode pad used in an ECG?
Model answer
The gel lowers the electrical resistance between the skin and the electrode. The weak signal is then recorded clearly with little interference.
4
What is a Holter monitor?
Model answer
A Holter monitor is a small portable ECG recorder worn for 24 hours or longer. The device catches irregular heartbeats that may not occur during a short hospital test.
5
An ECG shows R waves 0.8 s apart. What is the heart rate?
Model answer
The heart rate is 75 beats per minute. The working is 60 ÷ 0.8 = 75.
6
How has ECG equipment improved patient monitoring?
Model answer
Modern ECG machines give digital traces that can be stored, compared and sent to a specialist instantly. Bedside monitors also sound an alarm when a dangerous rhythm appears.

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