Biomedical Equipment Technology & Function Flashcards
7 cards from real CABT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Biomedical Equipment Technology & Function flashcards as text
During preventive maintenance on a hospital bed, which electrical safety test measures the current that could flow through a patient touching the bed frame and a grounded surface?
Answer: Chassis leakage current test
Chassis leakage current testing measures current flowing from the equipment chassis to ground, simulating the shock hazard a patient could experience.
An anesthesia machine's low-pressure system includes all of the following EXCEPT:
Answer: Pressure-reducing regulators
Pressure-reducing regulators are part of the intermediate-pressure system; the low-pressure system begins after the flowmeters and includes the vaporizer and breathing circuit.
A transcutaneous electrical nerve stimulator (TENS) unit is contraindicated for placement over which area?
Answer: Carotid sinus area of the neck
TENS electrode placement over the carotid sinus can trigger vagal reflexes, causing bradycardia or hypotension and is therefore strictly contraindicated.
In a phototherapy unit used for neonatal jaundice, the therapeutic parameter that should be verified during PM is:
Answer: Irradiance measured in µW/cm²/nm
Irradiance (spectral power output) determines the effectiveness of bilirubin photo-isomerization; it must meet clinical thresholds (typically ≥30 µW/cm²/nm) to be therapeutic.
Which gas is used as the primary pneumatic drive gas in most hospital ventilators and why?
Answer: Air or oxygen at 50 psi, because it provides consistent driving pressure for bellows or pistons
Hospital ventilators use 50 psi compressed air or oxygen as a pneumatic drive source because this pressure reliably actuates pneumatic valves and drives bellows or pistons.
A Doppler ultrasound flow detector operates on the principle that:
Answer: Moving red blood cells shift the frequency of reflected ultrasound proportional to their velocity
The Doppler effect causes the frequency of ultrasound reflected from moving erythrocytes to shift up or down relative to flow direction, allowing velocity calculation.
When calibrating an invasive blood pressure transducer, zeroing the transducer at the level of the phlebostatic axis compensates for:
Answer: Hydrostatic pressure error due to fluid column height
Zeroing at the phlebostatic axis eliminates hydrostatic pressure added by or subtracted from the fluid column between the transducer and the patient's heart.