CBET General Practice 2 — Questions and Answers
Question 1: A biomedical technician is troubleshooting an infusion pump that delivers inconsistent flow rates. Which component is MOST likely responsible?
- Occlusion sensor
- Peristaltic pump mechanism (Correct answer)
- AC power supply
- LCD display module
Correct answer: Peristaltic pump mechanism
The peristaltic pump mechanism directly controls fluid delivery, and wear or misalignment causes inconsistent flow rates.
Question 2: According to NFPA 99, the maximum allowable ground resistance for a receptacle in a patient care area is:
- 0.5 ohms
- 0.1 ohms (Correct answer)
- 1.0 ohms
- 0.2 ohms
Correct answer: 0.1 ohms
NFPA 99 requires receptacle ground resistance to not exceed 0.1 ohms in patient care areas to ensure electrical safety.
Question 3: Which type of fire extinguisher is appropriate for electrical equipment fires in a biomedical equipment area?
- Class A (water)
- Class B (foam)
- Class C (CO2 or dry chemical) (Correct answer)
- Class D (dry powder)
Correct answer: Class C (CO2 or dry chemical)
Class C extinguishers use non-conductive agents like CO2 or dry chemical, making them safe for energized electrical equipment fires.
Question 4: A patient monitor displays an artifact that disappears when the patient's lead wires are disconnected. This MOST likely indicates:
- A faulty amplifier in the monitor
- EMI from external sources coupling through the leads (Correct answer)
- A defective power supply
- Software corruption in the monitor
Correct answer: EMI from external sources coupling through the leads
When artifact disappears upon lead disconnection, the leads are acting as antennas picking up electromagnetic interference from external sources.
Question 5: The term 'microshock' refers to hazardous current delivered:
- Through intact skin at levels above 100 mA
- Directly to the heart via an intracardiac catheter at levels as low as 10 µA (Correct answer)
- Through a defibrillator paddle during cardioversion
- Via a transcutaneous electrical nerve stimulator
Correct answer: Directly to the heart via an intracardiac catheter at levels as low as 10 µA
Microshock occurs when current bypasses skin resistance and reaches the heart directly, where as little as 10 µA can induce ventricular fibrillation.
Question 6: During preventive maintenance on a ventilator, the BIOMED finds the exhalation valve is slow to close. The MOST immediate patient safety concern is:
- Increased FiO2 delivery
- Inadequate tidal volume delivery due to gas leakage (Correct answer)
- Elevated baseline airway pressure
- Reduced alarm sensitivity
Correct answer: Inadequate tidal volume delivery due to gas leakage
A slow-closing exhalation valve allows delivered gas to escape before full tidal volume is delivered to the patient's lungs.
Question 7: Which standard specifically governs the safety requirements for medical electrical equipment in the United States?
- IEC 60601-1
- ANSI/AAMI ES60601-1 (Correct answer)
- UL 2601-1
- NFPA 70E
Correct answer: ANSI/AAMI ES60601-1
ANSI/AAMI ES60601-1 is the US adoption of IEC 60601-1 and governs general safety requirements for medical electrical equipment.
CBET General Practice 2
A biomedical technician is troubleshooting an infusion pump that delivers inconsistent flow rates.
Which component is MOST likely responsible?