BTC BTC Biomedical Equipment Calibration & Testing 2 — Questions and Answers
Question 1: What is a 'test uncertainty ratio' (TUR) and why does it matter in calibration?
- Ratio of device weight to calibrator weight
- Ratio of the calibration standard's accuracy to the device's tolerance, should be at least 4:1 (Correct answer)
- The percentage of failed calibrations
- The ratio of pass to fail results
Correct answer: Ratio of the calibration standard's accuracy to the device's tolerance, should be at least 4:1
A TUR of at least 4:1 means the calibration standard is four times more accurate than the device tolerance, ensuring the calibration itself is reliable.
Question 2: When testing electrical safety on patient-connected equipment, what does 'chassis leakage current' measure?
- Current flowing through the power cord
- Unintended current flowing from the device chassis to ground through a patient (Correct answer)
- Voltage across the power supply
- Current drawn by the display screen
Correct answer: Unintended current flowing from the device chassis to ground through a patient
Chassis leakage current is the unintended current that could flow from the device's chassis through a patient to ground, posing an electrocution risk.
Question 3: According to ANSI/AAMI ES60601-1, what is the maximum allowable chassis leakage current for patient-connected equipment in normal condition?
- 500 µA
- 100 µA (Correct answer)
- 10 mA
- 1 mA
Correct answer: 100 µA
ANSI/AAMI ES60601-1 limits chassis leakage current to 100 µA in normal condition to prevent harm to patients.
Question 4: What is the purpose of a 'load test' when calibrating a defibrillator?
- To test the device's wireless connectivity
- To verify that the delivered energy output matches the selected energy setting into a known resistance load (Correct answer)
- To check the battery charge level
- To test alarm loudness
Correct answer: To verify that the delivered energy output matches the selected energy setting into a known resistance load
A load test verifies that the defibrillator delivers the correct energy (in joules) into a standard resistive load, ensuring therapeutic doses are accurate.
Question 5: Which calibration tool is specifically required when calibrating a pulse oximeter?
- Multimeter
- Functional SpO2 simulator that generates optical signals (Correct answer)
- Oscilloscope
- Pressure gauge
Correct answer: Functional SpO2 simulator that generates optical signals
A functional SpO2 simulator generates optical test signals that mimic various saturation levels, allowing verification of the oximeter's readings.
Question 6: What does 'out-of-tolerance' mean when documented in a calibration report?
- The equipment is overheating
- The device's measured performance falls outside the acceptable specification limits (Correct answer)
- The calibration certificate has expired
- The device requires a software update
Correct answer: The device's measured performance falls outside the acceptable specification limits
Out-of-tolerance means the device's actual performance deviates beyond the specified acceptable limits, requiring adjustment, repair, or removal from service.
BTC BTC Biomedical Equipment Calibration & Testing 2
What is a 'test uncertainty ratio' (TUR) and why does it matter in calibration?