acoustic studies
frequencer v2
Studies on acoustics

If you Google “studies on acoustics” on the Internet, you’ll be referred to more than 22 million references. Acoustic technology has been widely used... in submarines as sonar generating very low frequencies (infrasound) to ensure safe navigation... in hospitals as scanners generating frequencies in the millions of Hz (ultrasound) to produce pictures of the human womb... in homes and cars as radio generating frequencies within the range of human hearing (sound) so that we may enjoy music. Sound at frequencies between 20Hz and 65Hz is what the Frequencer™ generates to liquefy mucus and clear the airways.

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White paper on acoustics and the Frequencer™

To better understand how acoustics may be used to effect human airway clearance, the expertise of both Marc Bacon, P. Eng., and Dr André Cantin, MD, was employed. Refer to the attached White Paper for summaries of studies and mathematical explanations as to why acoustics can have a positive effect on mucus and airway clearance.

White Paper

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Study with the Frequencer™ and CPT

This study showed that for many CF patients, treatments with the Frequencer™ used in a sitting or slightly reclined position were as effective as CPT treatment performed by technicians with the patient in a postural drainage position.

Frequencer Study Result

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Clinical study at UCSD

In an abstract presented at the 2010 AARC meeting in Las Vegas, UCSD (University of California in San Diego), and later published in the Science Journal of the American Association for Respiratory Care, presented results of a non-subsidised study on usage of the Frequencer™ and sputum production. The USCD already had in place a protocol identifying the Therapy Vest and the IPV as primary choices and the G5, Flutter and Acapella as secondary options. With their non-subsidized study, they wanted to classify the Frequencer™ and its new acoustic technology in airway clearance. Their conclusion was “...the Frequencer, can safely be considered to be one of the preferred or primary choices by the patient and RCP (Repiratory Care Practitioner)”.

Respiratory Care 2010

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Studies on resonant frequency

Acoustic resonance is the tendency of a body to absorb more energy at a frequency that matches its own natural resonant frequency than it does at other frequencies. The classic example of this is breaking a wine glass with sound at the precise resonant frequency of the glass. Everything around us has a very specific resonant frequency, human body parts included ... Two studies performed in 2002, one by the US Navy and a second by the US Department of Commerce, concluded that the resonant frequency of the human lung is approximately 35-42Hz. This range is important as the Frequencer™ can generate frequencies between 20Hz and 65Hz. Conversely, airway clearance systems using air compressors generate frequencies in the range of 16-20Hz and Chest Physiotherapy (CPT) generates frequencies in the range of only 4-6Hz; both are well below the resonant frequency of the human lung.


Lung resonant frequency

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Study on wave depth-of-penetration in the chest

This Université de Paris study showed that mechanical coupling is much stronger than acoustic coupling on the surface of the chest, but rapidly diminishes in strength with depth of penetration. Conversely, acoustic coupling is weaker at the surface but diminishes less with depth of penetration.

Transmission d'une onde - Paris

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Study on the Frequencer™ sound level

This study showed the decibel level of the Frequencer™ is about equal to that of human laughter; well below the maximum dB level tolerated by human ears.

Test Report

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Study on force applied to the patient’s chest

Because airway clearance often deals with patients already weakened by their condition, the strain associated with the technique used to clear the airways may impact patient condition. This lab study performed by Bruno Tardif, Eng., compares the force applied to a patient’s chest by the Frequencer™ versus the force applied by the hand of a technician in Chest Physiotherapy (CPT).


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Satisfaction surveys

Using a Baylor University standardised questionnaire, patients assess their currently used clearance technique versus the Frequencer™ over a 2-week trial period.


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Patient and parent comments

CF patients need airway clearance on a daily basis. The more they clear their lungs, the lower their risk of infection. Over the years, patients have tried many of the airway clearance techniques available; as such, they are the best judges, taking into account varying factors including: efficacy, autonomy, transportation, set up, weight, treatment duration, strain of use, noise-level, discretion of use, compliance, etc.

Parents are also very concerned by airway clearance technique, especially if they have to submit to daily clapping to a CF child or infant.

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Next: Study Results - Clinical Studies >>

To be able to stand up and breathe freely, you must fight.

Quotation of Jiang Zilong