The forced expiratory volume (FEV) in one second is used in the diagnosis of lung illnesses. For the measurement of this here, the student carrying out the test breathes normally a few times, presses out all the air he or she can, takes a deep breath and holds it for a moment before (at the beginning of measurement) force breathing out as much air as he or she can right from the start of measurement.
Further to this, the vital capacity (as inspiratory VC = IVC) is again to be determined here as it is required for the FEV1 and IVC quotient which is called the Tiffeneau value:
Tiffeneau value = FEV1 / IVC [%] (1)
With healthy young people, this quotient is 75%. In the case of a so-called obstructive respiratory illness, such as bronchial asthma, the value is far below 75%, as the forced expiratory volume per second is greatly reduced. As this FEV value, just as the vital capacity, depends on the age of the person, among others, older people only reach a value of about 70%.
In contrast to the obstructive illnesses, there are also so-called restrictive respiratory illnesses which cannot be determined using this method.
- Uses the same spirometer design which is also used in medical diagnostics
- One-way turbine system avoids infections
- All methods used in medical diagnostics can be performed
- Takes advantage of modern wireless data acquisition technology
- Determine the inspiratory vital capacity (IVC) in litres.
- Determine the one-second forced expiratory volume in one second (FEV1) in litres.
What you can learn about
- Lung illness
- Forced expiratory volume (FEV)
- Vital capacity
- Tiffeneau value
- Obstructive respiratory illness
- Restrictive respiratory illnesses