CABT Equipment Maintenance and Troubleshooting 2 — Questions and Answers
Question 1: A ventilator alarms 'low pressure' shortly after the patient was suctioned. What is the most likely cause?
- Kinked inspiratory limb tubing
- Patient circuit disconnect or leak (Correct answer)
- Obstructed expiratory valve
- Faulty flow sensor
Correct answer: Patient circuit disconnect or leak
A low-pressure alarm following suctioning typically indicates an accidental circuit disconnection or a loose connection that allowed air to escape.
Question 2: Which maintenance schedule item is considered a 'time-based' preventive maintenance task?
- Replacing an infusion pump battery every 2 years regardless of cycles (Correct answer)
- Cleaning a device only when visibly soiled
- Calibrating a device after each repair
- Replacing a filter only when flow is reduced
Correct answer: Replacing an infusion pump battery every 2 years regardless of cycles
Time-based preventive maintenance replaces components on a fixed calendar interval regardless of use or condition, such as replacing a battery every two years.
Question 3: An ECG monitor displays a wandering baseline. Which intervention should the biomedical technician perform first?
- Replace the ECG cable
- Check and improve electrode-to-skin contact (Correct answer)
- Adjust the low-frequency filter setting
- Inspect the display board
Correct answer: Check and improve electrode-to-skin contact
A wandering baseline is most commonly caused by poor electrode-to-skin contact due to dry gel, motion, or improper placement.
Question 4: When performing electrical safety testing on patient care equipment, the ground wire resistance should typically not exceed:
- 0.5 ohms (Correct answer)
- 1.0 ohm
- 5.0 ohms
- 10.0 ohms
Correct answer: 0.5 ohms
NFPA 99 and AAMI standards generally require that the resistance of the equipment ground (protective earth) conductor not exceed 0.5 ohms.
Question 5: A defibrillator charges to 200 J but only delivers 150 J during a test discharge. The MOST likely cause is:
- Defective display panel
- Capacitor energy leakage or degradation (Correct answer)
- Incorrect paddle size selected
- Faulty synchronization circuit
Correct answer: Capacitor energy leakage or degradation
A significant gap between stored and delivered energy typically indicates capacitor degradation, which causes energy to leak before discharge.
Question 6: Which of the following best describes the purpose of a 'load test' on an uninterruptible power supply (UPS)?
- Verifies input voltage regulation under steady-state conditions
- Confirms the UPS can deliver rated output power for a specified duration (Correct answer)
- Tests the surge suppression circuitry
- Checks the battery charger input current
Correct answer: Confirms the UPS can deliver rated output power for a specified duration
A load test applies rated or specified load to the UPS to verify it sustains output power for the required backup duration.
Question 7: A pulse oximeter consistently reads 2% higher than co-oximeter arterial blood gas values. This type of error is called:
- Precision error
- Random error
- Systematic (bias) error (Correct answer)
- Calibration drift
Correct answer: Systematic (bias) error
A consistent offset in one direction between a device's readings and a reference standard is defined as systematic error or bias.
CABT Equipment Maintenance and Troubleshooting 2
A ventilator alarms 'low pressure' shortly after the patient was suctioned.
What is the most likely cause?