Piezo-Electric Respiratory Effort
Definition:
A piezo-electric respiratory effort belt can be used to monitor breathing by measuring changes in chest/abdominal volume.
Typical Applications:
Respiratory effort belts are often used to measure complex respiratory signals, such as respiratory effort and respiratory rates.
Typical BioRadio Configuration:
- This respiratory effort belt outputs a voltage which is proportional to the change in length of the belt.
- Coupling: DC
- Range: ±140 mV
- Filter: 2nd order, lowpass Butterworth, with order upper cutoff 5.00 Hz
Typical Setup:
- This belt should be placed on the torso:
Step 1:
Securely fasten belt around the subject just above the stomach and below the rib cage. In this position, both diaphragm and chest breathing should be captured. Step 2:
The respiratory effort bands have two shades of color on them: dark and light. The Piezo-Electric sensor is located in the center of the dark portion of the band with a little label over the top of it. Make sure the dark portion of the band spans the chest and/or abdomen with the label in the center.
Common Questions:
Q: Which direction of the signal (positive versus negative) correlates to inhaling and which correlates to exhaling?
A:
When inhaling, the signal should increase. When exhaling, the signal should decrease.
Q: Why is the signal much larger or much smaller than I expected?
A:
Piezo-Electric belts are subject to trapping artifact: when a portion of the belt becomes “trapped” as a person moves, resulting in variable tension along the belt circumference. This artifact can also cause a false signal when belt tension suddenly changes with a change in body position. Verify that the belt is not trapped and repeat the collection.