Activ8rlives Peak Flow meter, User Manual

Page: 11 / 52

11
Predicted Forced Expiratory Volume in 1
second (FEV
1
)
Definition: FEV
1
is the maximal amount of air you can forcefully exhale in one second.
It is then converted to a percentage of normal. For example, your FEV1 may be 80% of predicted
based on your height, weight, and race.
FEV
1
is a marker for the degree of obstruction in your lungs:
FEV1 greater 80% of predicted= normal
FEV1 60% to 79% of predicted = Mild obstruction
FEV1 40% to 59% of predicted = Moderate obstruction
FEV1 less than 40% of predicted = Severe obstruction
You can calculate your PREDICTED FEV
1
using a powerful on-line tool provided by Dynamic MT
http://www.dynamicmt.com/dataform3.html
Many clinicians use the predicted values defined by NHAINES III.
Or you can ask your doctor to give you your predicted value.
Remember that you have to enter the value in units of Litres in 1 second.
The number will be in the range of: 1 – 6.
IF IN DOUBT, CONTACT YOUR DOCTOR FOR ADVICE.