CBET General Practice 3

Question 1

A pulse oximeter reads 98% SpO2 but the patient appears cyanotic. Which condition MOST likely explains this discrepancy?

Accepted Answer

Carbon monoxide poisoning causing carboxyhemoglobin

Answer

Pulse oximetry cannot distinguish carboxyhemoglobin from oxyhemoglobin, so CO poisoning produces falsely elevated SpO2 readings despite true hypoxia.

Question 2

The primary purpose of a Faraday cage in a medical imaging suite is to:

Accepted Answer

Prevent external RF signals from interfering with MRI signals

Answer

A Faraday cage blocks external radiofrequency signals that would interfere with the extremely weak MRI signals being detected.

Question 3

When calibrating a patient scale used for medication dosing, a biomedical technician should use NIST-traceable weights primarily to:

Accepted Answer

Ensure measurements are accurate relative to a national standard

Answer

NIST-traceable weights provide an unbroken chain of calibration to national standards, ensuring measurement accuracy and regulatory compliance.

Question 4

In a 3-phase electrical system supplying medical imaging equipment, an open neutral conductor would MOST likely cause:

Accepted Answer

Overvoltage on some phases damaging connected equipment

Answer

An open neutral in a 3-phase system causes voltage imbalance, resulting in overvoltage on some phases that can damage connected equipment.

Question 5

A surgical electrosurgical unit (ESU) causes interference on a nearby patient monitor. The FIRST corrective action should be:

Accepted Answer

Check and ensure proper placement and contact of the ESU dispersive electrode

Answer

Improper dispersive electrode placement causes high-frequency current to seek alternate paths, creating interference in nearby monitoring equipment.

CBET - Certified Biomedical Equipment Technician Practice Test