Table 2.

Details of the oscillometry technique from a clinical and a preclinical viewpoint

	Clinical	Preclinical (Small Laboratory Animals)
Commercial device	Available	Available
Current level of use	Research, clinical practice	Routine research
Guidelines/practical recommendations	Available	Available
Reference values	Available	Available
Subject’s state of consciousness	Unaltered	Anesthetized
Subject’s position	Seated, supine, upright	Supine
Subject’s connection to the device	Mouthpiece	Tracheotomy or oral intubation
Subject’s breathing pattern	Spontaneous: usually breathing at tidal volume	Mechanical ventilation
Subject’s lung volume at the time of assessment	Variable: spontaneous volume adopted by the subject	Standardized transpulmonary pressure
Subject’s airway tree	Intact, mouth to lung	Partial: lower airways only
Measurement type	Finite perturbations	Finite perturbations
Measurement duration	20 s to 1 min	1 to 16 s
Signal generator	Loudspeaker Moving mesh	Computer-controlled piston ventilator
Type of input signal	Single frequency Multifrequency	Single frequency Multifrequency Optimized ventilator waveform
Nature of input signal	Impulse Predefined sine waves	Predefined sine waves
Frequency range	Variable: typically 5 to ∼40 Hz	Variable: typically 0.5 to 20 Hz
Delivery of input signal	Superimposed on subject’s breathing	During a brief apneic period
Aerosol administration	Via the mouth	Intratracheal
Output	Input impedance	Input or transfer impedance
Interpretation of impedance	Response at set frequencies Shape analysis of the frequency-response curves Area-under-the-curve	Mathematical models and derived parameters
Strengths	Structure-function link Access to lung periphery Absolute values Sensitivity Measurement during regular quiet breathing	Structure-function link Access to lung periphery Absolute values Sensitivity Precision: measurements made under fully controlled conditions
Limitations	Assessment over a limited span of the respiratory pressure, volume, and flow ranges Chest wall contribution Standardization of lung volumes	Anesthesia Invasive measurements Variable chest wall contributions across species