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

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


Purpose: 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.

Methods: 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.

Results: 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.

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

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cystic Fibrosis / therapy*
  • Humans
  • Mucociliary Clearance
  • Physical Therapy Modalities / instrumentation*
  • Respiratory Therapy / instrumentation*
  • Respiratory Therapy / methods
  • Sputum / metabolism
  • Treatment Outcome