CBET Patient Monitoring Systems 2 — Questions and Answers
Question 1: What is the typical frequency range of an ECG amplifier's bandwidth for diagnostic-quality monitoring?
- 0.5-40 Hz
- 0.05-150 Hz (Correct answer)
- 1-500 Hz
- 10-1000 Hz
Correct answer: 0.05-150 Hz
Diagnostic-quality ECG requires 0.05-150 Hz bandwidth to capture all waveform components accurately.
Monitoring mode (0.5-40 Hz) can distort ST segments, potentially masking ischemia. Biomedical technicians must verify frequency response using ECG simulators during PM.
Question 2: What does NIBP stand for and what method do most patient monitors use to measure it?
- Non-Invasive Blood Pressure - oscillometric method detecting arterial wall oscillations in an inflated cuff (Correct answer)
- Neural Impulse Blood Pressure - direct nerve stimulation
- Nominal Internal Blood Pressure - catheter-based measurement
- Non-Indexed Baseline Pressure - calculated from heart rate
Correct answer: Non-Invasive Blood Pressure - oscillometric method detecting arterial wall oscillations in an inflated cuff
NIBP (Non-Invasive Blood Pressure) uses the oscillometric method, detecting pressure oscillations as the cuff deflates.
MAP is the most accurate directly-measured value. Common issues include air leaks in cuff/tubing and algorithm errors with arrhythmias or excessive motion.
Question 3: What is the purpose of the central monitoring station in a patient monitoring system?
- To store all hospital medical records
- To display and monitor multiple patients' vital signs simultaneously from a central location (Correct answer)
- To control all medical equipment
- To manage medication dispensing
Correct answer: To display and monitor multiple patients' vital signs simultaneously from a central location
A central station receives and displays real-time vital signs from multiple bedside monitors for simultaneous observation.
Features include full-disclosure waveform storage, arrhythmia detection, and alarm notification via pagers/phones. Downtime reduces monitoring capability for the entire unit.
Question 4: When troubleshooting a patient monitor displaying 'Lead Off' for ECG, what should a biomedical technician check?
- The monitor software version
- The electrode contact quality, lead wire integrity, and cable connections from patient to monitor (Correct answer)
- The monitor battery level
- The room temperature
Correct answer: The electrode contact quality, lead wire integrity, and cable connections from patient to monitor
'Lead Off' means a break in the electrical circuit between the patient's skin and the ECG amplifier input.
Simulate a known-good signal using an ECG simulator to isolate whether the issue is patient-side or monitor-side. Repeated lead-off issues with a specific cable model may indicate a design problem.
Question 5: What parameter does capnography monitor and what is the normal end-tidal CO2 (EtCO2) range for a healthy adult?
- Blood oxygen levels, 95-100%
- Exhaled carbon dioxide concentration, 35-45 mmHg (Correct answer)
- Inhaled oxygen concentration, 21%
- Respiratory muscle effort, 10-20 cmH2O
Correct answer: Exhaled carbon dioxide concentration, 35-45 mmHg
Capnography monitors CO2 concentration in exhaled breath. Normal EtCO2 is 35-45 mmHg.
Two configurations: mainstream (sensor at airway) and sidestream (gas sampled to remote sensor). Biomedical technicians calibrate with known CO2 concentration gas during PM.
Question 6: What is the difference between invasive and non-invasive blood pressure monitoring, and when is invasive monitoring preferred?
- Invasive is less accurate but faster
- Invasive uses an arterial catheter and transducer for continuous beat-to-beat monitoring in hemodynamically unstable patients (Correct answer)
- Invasive uses a larger cuff
- There is no clinical difference
Correct answer: Invasive uses an arterial catheter and transducer for continuous beat-to-beat monitoring in hemodynamically unstable patients
Invasive monitoring uses an arterial catheter connected to a pressure transducer for continuous real-time measurement.
Biomedical technicians verify transducer accuracy using a calibrated pressure source. Staff must be educated on proper leveling (phlebostatic axis) and zeroing procedures.
CBET Patient Monitoring Systems 2
What is the typical frequency range of an ECG amplifier's bandwidth for diagnostic-quality monitoring?