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Clin Invest Med. 2006 Jun;29(3):159-65.

Mechanical airway clearance using the frequencer electro-acoustical transducer in cystic fibrosis.

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Respiratory Division, Department of Medicine, Centre Hospitalier Universitaire de Sherbrooke, Quebec.



Clearance of mucus from airways is the cornerstone of therapy for lung disease in patients with cystic fibrosis (CF). This paper describes the operation of the Frequencer, a novel respiratory physiotherapy device comprised of an electro-acoustical transducer. We hypothesized that the Frequencer would be a safe and effective therapy to help clear secretions from the airways of subjects with CF.


To verify this hypothesis, 22 individuals with CF were recruited to this study comparing sputum production during conventional chest physiotherapy (CCPT) and Frequencer therapy using a crossover design. The sputum weight was the main outcome measure.


Sputum weight was found to be a reproducible measure of the efficacy of chest physiotherapy in individual patients. The Frequencer induced airway clearance in patients with CF that was equivalent to that of CCPT. Furthermore, treatment of a 4% mucin preparation ex vivo with the Frequencer significantly reduced the viscosity of the mucin solution as determined in a capillary rheometer.


These results indicate the Frequencer is safe and as effective as CCPT in inducing airway clearance in patients with CF.

[Indexed for MEDLINE]

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