CBET Surgical Equipment Technology 5 — Questions and Answers
Question 1: A pneumatic tourniquet used in orthopedic surgery is displaying pressure that fluctuates ±30 mmHg during inflation. The MOST likely cause is:
- Leak in the cuff bladder or connecting tubing (Correct answer)
- Incorrect limb occlusion pressure setting
- Low wall gas supply pressure
- Cuff applied over excessive padding
Correct answer: Leak in the cuff bladder or connecting tubing
Pressure fluctuations in a pneumatic tourniquet are most commonly caused by air leaks in the cuff bladder or tubing connections.
Question 2: Which safety feature prevents inadvertent activation of an electrosurgical unit when the active electrode is not in use?
- Holster with passive safety switch (Correct answer)
- Footswitch interlock
- Auto-off timer relay
- Impedance monitoring circuit
Correct answer: Holster with passive safety switch
A holster with a passive safety switch deactivates the active electrode output when placed in the holster, preventing accidental burns.
Question 3: During arthroscopic surgery, the fluid pump pressure is set to 60 mmHg but the surgeon reports poor visualization. What should the BMET check FIRST?
- Integrity of the arthroscope sheath seals and outflow cannula patency (Correct answer)
- Pump motor speed calibration
- Fluid bag temperature
- Light source cable connection
Correct answer: Integrity of the arthroscope sheath seals and outflow cannula patency
Leaking sheath seals or blocked outflow cannulas prevent adequate joint distension, causing poor visualization despite correct pump settings.
Question 4: What is the primary hazard associated with improper grounding of a surgical robot in the OR?
- Leakage current could flow through the patient, causing burns or cardiac events (Correct answer)
- Robot positional accuracy will degrade
- Instrument servo motors may stall
- Vision system latency will increase
Correct answer: Leakage current could flow through the patient, causing burns or cardiac events
Improper grounding of electrically powered equipment in the OR can create leakage current paths through the patient, posing serious electrical safety risks.
Question 5: A harmonic scalpel generates heat through which mechanism?
- Ultrasonic vibration causing molecular friction within tissue (Correct answer)
- Radiofrequency current passed through tissue
- Laser photon absorption by chromophores
- Resistive heating of a metal blade
Correct answer: Ultrasonic vibration causing molecular friction within tissue
Harmonic scalpels use ultrasonic vibration (typically 55,500 Hz) that causes rapid protein denaturation through molecular friction, achieving cutting and coagulation simultaneously.
Question 6: When performing electrical safety testing on a powered surgical drill, which test is used to verify that current does not flow through the equipment's chassis to ground during normal operation?
- Chassis leakage current test (Correct answer)
- Dielectric strength test
- Insulation resistance test
- Ground continuity test
Correct answer: Chassis leakage current test
The chassis leakage current test measures any unintended current flowing from the equipment chassis to ground, ensuring patient and user safety.
Question 7: A surgical headlight powered by a fiber optic light source produces uneven illumination with a dark center spot. The MOST probable cause is:
- Broken fiber bundles at the center of the light guide cable (Correct answer)
- Insufficient lamp wattage
- Contaminated headlight lens
- Incompatible light source coupling adapter
Correct answer: Broken fiber bundles at the center of the light guide cable
Broken optical fibers, especially centrally located ones, create dark spots in the illumination pattern because those fibers no longer transmit light.
CBET Surgical Equipment Technology 5
A pneumatic tourniquet used in orthopedic surgery is displaying pressure that fluctuates ±30 mmHg during inflation.
The MOST likely cause is: