Special Testing & Calibration Procedures A Flashcards
In an ABG, which variables are calculated?
O2sat and bicarbonate
What is the gold standard for diagnosing GERD?
Esophageal pH monitoring
How do you tell when an esophageal catheter is in the right place?
Advance catheter until the pH drops. Then pull pack untili pH normalizes. Then pull back another 5 cm.
What’s the best way to determine respiratory effort?
Esophageal manometry
What is a montage?
The channel layout in a sleep study.
In a typical sleep study montage, the low frequency is usually set for ___.
0.3 Hz
Low frequency on the body & snoring is set for ___.
10 Hz
Low frequency for nasal airflow, thoracic, and abdomen is set for ___.
0.1 Hz
The high frequency is usually set for ___.
35 Hz
The high frequency for the ECG is ___.
70 Hz
The high frequency for the body and snore sensors are usually set for ___.
100 Hz
The high frequency for the nasal airflow, thoracic, and abdomen is usually set for ___.
15 hz
The sensitivity on all instruments is ___.
The sensitivity on the ECG is ___.
The sensitivity on the chin is ___.
7 uV/mm
ECG is 20 uV/mm
Chin is 2 uV/mm
What is the sampling rate for all equipment?
500 hz
What is the sampling rate for the nasal airflow, thoracic, and abdomen?
100 Hz
What is the sampling rate for the SpO2?
25 Hz
What does the Nyquist Theorem state?
The sampling rate must be at least twice as much as the signal bandwidth.
What are the montage settings for all the electrodes except ECG? (LFF, HFF, Sensitivity, and Sampling Rate)
LFF = 0.3
HFF = 35
Sensitivity: 7 uV/mm
Sampling rate: 500 Hz
In a referential montage, each channel represents the difference between a certain electrode and a ___.
In a bipolar montage, each channel represents the difference between ___.
Reference electrode.
Two adjacent or exploring electordes.
Which type of montage is most often used in polysomnography?
Referential montage
When do you see bipolar montages?
EMG and ECG
What is a time constant?
The time in seconds that it takes for a waveform to drop to 37% of its calculated amplitude.