CBET Ultimate 3 — Questions and Answers
Question 1: When testing ground wire resistance on patient care equipment, AAMI ES1 specifies the resistance should not exceed:
- 0.1 ohm (Correct answer)
- 0.5 ohm
- 1.0 ohm
- 5.0 ohm
Correct answer: 0.1 ohm
AAMI ES1 specifies that ground wire resistance from chassis to the ground pin of the power cord should not exceed 0.1 ohm.
Question 2: A pulse oximeter reads SpO2 at 85% but the patient appears clinically stable. What artifact is MOST likely causing a falsely low reading?
- Hyperbilirubinemia
- Motion artifact or poor perfusion at the probe site (Correct answer)
- Hyperoxia
- High ambient oxygen concentration
Correct answer: Motion artifact or poor perfusion at the probe site
Motion and poor peripheral perfusion are the most common causes of falsely low SpO2 readings with pulse oximetry.
Question 3: Which sterilization method is MOST appropriate for heat-sensitive flexible endoscopes?
- Steam autoclave at 134°C
- Ethylene oxide (EtO) gas sterilization (Correct answer)
- Dry heat oven
- Radiation sterilization
Correct answer: Ethylene oxide (EtO) gas sterilization
Ethylene oxide sterilizes at low temperatures (~55°C), making it suitable for heat- and moisture-sensitive devices like flexible endoscopes.
Question 4: In an infusion pump, what is the primary purpose of the air-in-line detector?
- To measure flow rate accuracy
- To detect air bubbles that could cause air embolism (Correct answer)
- To prevent free-flow drug delivery
- To monitor reservoir volume
Correct answer: To detect air bubbles that could cause air embolism
The air-in-line detector uses ultrasonic sensing to stop the pump when air bubbles are detected, preventing venous air embolism.
Question 5: What is the function of a ballast in fluorescent surgical lighting?
- To control light color temperature
- To limit current and stabilize the arc discharge in the lamp (Correct answer)
- To convert AC to DC power
- To focus the light beam
Correct answer: To limit current and stabilize the arc discharge in the lamp
The ballast provides starting voltage and then limits current to prevent the lamp's negative resistance characteristic from causing a runaway increase in current.
Question 6: A hospital-grade receptacle has which distinguishing feature compared to standard commercial receptacles?
- Higher voltage rating
- Green dot marking and heavier-duty contacts with greater retention force (Correct answer)
- GFCI protection built-in
- Isolated ground on every outlet
Correct answer: Green dot marking and heavier-duty contacts with greater retention force
Hospital-grade receptacles are identified by a green dot and are constructed with heavy-duty contacts that maintain secure plug retention to prevent unintentional disconnection.
Question 7: When inspecting a surgical electrosurgical unit (ESU), which parameter is tested to verify patient safety?
- Output frequency accuracy
- Return electrode contact quality monitoring (RECM) threshold (Correct answer)
- Cutting waveform duty cycle only
- RF output power linearity
Correct answer: Return electrode contact quality monitoring (RECM) threshold
Return electrode contact quality monitoring (RECM) verifies that the dispersive electrode has adequate contact area to prevent burns at the return site.
CBET Ultimate 3
When testing ground wire resistance on patient care equipment, AAMI ES1 specifies the resistance should not exceed: