Systematic and Random Errors in the Determination of Respiratory Impedance by Means of the Forced Oscillation Technique: A Theoretical Study

The measurement of the impedance of the respiratory system by means of the forced oscillation technique is disturbed by the breathing signal of the subject. The latter introduces systematic and random errors on the obtained impedance values. The size of these errors depends on the relative power of the breathing signal with respect to the forced oscillatory signal x2.