Oscillometer: PDD-301/so

The Forced Oscillation Technique (FOT) offers a modern and reliable but economical method for the impedance measurement of respiratory system.
During test the patient is only asked to breath normally and no respiratory manoeuvre is needed.
Since the test requires minimum co-operation from the patients, the FOT device is and uniquely applicable in paediatric pulmonology

  • Measurement of the components of the airway impedance at different frequencies
  • Determination of the resonance frequency of the airways
  • Average calculation of Reproducible Impedance Spectra
  • Model evaluation of Impedance Spectra
  • Calculation of Resistance / Elastance / Inertance of the respiratory system
  • Random induced frequencies
  • Sequential induced frequencies

Software system overview 

  • Measurement modes
  • Measured parameters
  • Accessories
  • Technical data
  • Respiratory impedance measurement
  • FVC measurement
  • IVC measurement
  • MVV measurement

Whole list of Pulmonary Function Tests’ parameters

  Forced Oscillation Technique
Rrs Resistive component of respiratory impedance
Irs Inertance of the airways
Crs Compliance of the respiratory system
fres Resonance frequency
  Forced ex and inspiration
FVC Forced Vital Capacity
FEV*0.5 Forced Expiratory Volume in 0.5 second
FEV*1.0 Forced Expiratory Volume in 1.0 second
FEV*0.5/IVC Ration of FEV*0.5 and IVC in %
FEV*0.5/FVC Ration of FEV*0.5 and FVC in %
FEV*1.0/IVC Ration of FEV*1.0 and IVC in %
FEV*1.0/FVC Ration of FEV*1.0 and FVC in %
PEF Peak Expiratory Flow
FEF*25-75% Forced mid-Expiratory Flow rate
FEF*75% Forced Expiratory Flow at 75% lung volume
FEF*50% Forced Expiratory Flow at 50% lung volume
FEF*25% Forced Expiratory Flow at 25% lung volume
FET Forced Expiratory Time
MTT Mean Transit Time
FIVC Forced Inspiratory Vital Capacity
FIV*0.5 Forced Inspiratory Volume in 0.5 sec
FIV*1.0 Forced Inspiratory Volume in 1.0 sec
PIF Peak Inspiratory Flow rate
FIF*25-75% Forced mid-Inspiratory Flow rate
  Static vital capacity
IVC Inspiratory Vital Capacity
IRV Inspiratory Reserve Volume
ERV Expiratory Reserve Volume
TV Tidal Volume
SVC Slow Vital Capacity
  Maximal Voluntary Ventilation
MVV Maximal Voluntary Ventilation
MVV*f Maximal Voluntary Ventilation Frequency
Flow meter Lilly type pneumotachometer with screen
Flow range ±15 l/s
Accuracy ±2% or 50 ml, whichever is greater
Dead space 36 ml
Resistance 60 Pa/l/s @ 15 l/s
Induced frequency range 4 Hz - 48 Hz
Induced pressure wave max. 0,2 kPa
Induced power max. 50W
Size without patient circuit Height: 300 mm
  Wide: 300 mm
  Deep: 150 mm
Weight 7,2 kg
Power supply 90 ÷ 260 VAC 50/60 Hz
Power consumption 75 VA


Device with the patient circuit  

Impedance as a function of frequency

Device with a child patient   Model matching for Reproducible Spectra
Historic Pachon oscillometer