ECG ECG Equipment and Maintenance 2 — Questions and Answers
Question 1: What is the purpose of the 60 Hz notch filter on an ECG machine?
- Remove baseline wander
- Eliminate AC power line interference (Correct answer)
- Reduce muscle artifact
- Improve P-wave visibility
Correct answer: Eliminate AC power line interference
The 60 Hz notch filter eliminates electrical interference from AC power lines, which is a common source of noise in US clinical environments.
Question 2: Which component of the ECG machine converts analog electrical signals to digital data?
- Amplifier
- Analog-to-digital converter (ADC) (Correct answer)
- Galvanometer
- Isolation transformer
Correct answer: Analog-to-digital converter (ADC)
The analog-to-digital converter (ADC) transforms the continuous analog voltage signals from electrodes into discrete digital values for processing and storage.
Question 3: How should ECG electrode gel be applied to ensure good conductivity?
- Thick layer covering the entire electrode
- Thin uniform layer between electrode and skin (Correct answer)
- Only around the edges of the electrode
- No gel needed with modern adhesive electrodes
Correct answer: Thin uniform layer between electrode and skin
A thin, uniform layer of conductive gel reduces impedance between the electrode and skin, improving signal quality without causing electrode movement.
Question 4: What is the recommended storage condition for ECG thermal paper?
- Direct sunlight to keep dry
- Cool, dry environment away from heat and chemicals (Correct answer)
- Refrigerated at 4°C
- High humidity to prevent static
Correct answer: Cool, dry environment away from heat and chemicals
ECG thermal paper should be stored in a cool, dry place away from heat, chemicals, and sunlight to prevent premature darkening of the thermal coating.
Question 5: What does a jagged, irregular baseline on an ECG tracing most likely indicate?
- Atrial fibrillation
- Poor electrode contact or muscle artifact (Correct answer)
- Ventricular tachycardia
- Pacemaker malfunction
Correct answer: Poor electrode contact or muscle artifact
A jagged, irregular baseline is typically caused by poor electrode contact, patient movement, or muscle tremor artifact rather than a cardiac dysrhythmia.
Question 6: When should an ECG machine undergo preventive maintenance calibration?
- Only when the battery dies
- According to the manufacturer's schedule, typically annually (Correct answer)
- Every 10 years
- Only after repairs
Correct answer: According to the manufacturer's schedule, typically annually
ECG machines require periodic preventive maintenance and calibration per manufacturer guidelines, usually annually, to ensure accurate and reliable recordings.
ECG ECG Equipment and Maintenance 2
What is the purpose of the 60 Hz notch filter on an ECG machine?