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Updated: Jun 5, 2026
Rapid Viscoelastic Characterization of Airway Mucus Using a Benchtop Rheometer
Published on: April 21, 2022
Symmetrical-waveform high-frequency oscillation increases artificial mucus flow without changing basal mucus
Stanislav Tatkov1, Rodger J Pack
1Institute of Food, Nutrition, and Human Health, College of Sciences, Massey University, Palmerston North, New Zealand.
Background:
The efficacy of symmetrical-waveform high-frequency oscillating (HFO) air flow for airway secretion clearance is controversial and debated in the literature.
Methods:
We conducted in vitro experiments with ovine tracheae to investigate the effects of symmetrical-waveform HFO on tracheal transport of artificial mucus. We mounted each trachea as an intact tube, with a 15(o) head-down tilt, infused artificial mucus (10 mL over one hour) at the caudal end of the trachea, and measured mucus-transport velocity as the time between the beginning of infusion and the first appearance of artificial mucus over 2 near-infrared sensors at the rostral end of the trachea and by measuring the amount of mucus emerging. In a second series of experiments we opened each trachea flat and with video microscopy we measured the transport velocity of plaques over the endogenous mucus sheet.
Results:
In the intact-trachea preparation, HFO at 20 Hz and 50 cm H(2)O increased mucus-transport velocity from 5.8 mm/min to 7.8 mm/min. HFO led to nearly half the artificial mucus being cleared during the infusion period. In the opened-trachea experiments the mean control transport velocity was 8.7 mm/min, and HFO, at 14 Hz or 20 Hz (and 50 cm H(2)O), did not significantly alter that velocity.
Conclusions:
Symmetrical-waveform HFO increases mucus-transport velocity and mucus clearance when a thick layer of mucus is present. This may be important when considering the mechanisms of mucus clearance and using HFO for secretion clearance.
