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Principles of Operation


The Vibralung Acoustical Percussor uses acoustics (sound waves) as its fundamental operating principle. The sound waves (quasi-musical tones and “white noise”) are generated by an electronic digitally controlled signal generator and reproduced with a high-fidelity audio loudspeaker.


The Vibralung Acoustical Percussor generates and couples sound energy to the column of gas in the patient’s airways through a simple mouthpiece assembly. In turn, the sound energy vibrates the column of gas in the airways during both the inspiratory and expiratory phases of the patient’s breathing cycle. As the patient breathes normally through the mouthpiece attached to the HHT, the acoustic sound waveforms are superimposed over the normal respiratory waveforms and travel throughout the lungs via the conducting airway system. A useful analogy for the manner in which various waveforms superimpose themselves over each other would be the way multiple ripples form on a pond, even ripples emanating from different directions, can pass through each other and continue along their intended pathway. Consequently, application of this technique is relatively effort-independent on the part of the patient, and does not require the patient to perform specialized breathing maneuvers, because the sound waves pass through normal respiratory pressure waves during resting breathing.


Frequency Spectrum


The Vibralung Acoustical Percussor generates a sinusoidal waveform composed of a continuous spectrum of overlapping frequencies (quasi-musical tones) ranging from 5 to 1,200 Hz. Most of these tones are within the audible range of human hearing and can be heard by the patient and people close by.


The 5 Hz tone is generated while no other tone is being generated and represents the digital “off state.” Although it is below the normal lower limit of human hearing, it is nevertheless present.


The frequencies are separated into four operating ranges that have been labeled as Low, Medium, High, and R2 and R5. The tones emitted at the L, M and H settings deliberately resemble a series of staccato musical notes, at a tempo of about 360 beats per minute, to provide a predictable sequence of frequencies. The tones at the R2 and R5 (Random Noise) settings are described as “white noise” and cover the full available spectrum for either 2 or 5 minutes respectively.


The therapeutic benefit from application of the Vibralung is through a mechanism known as “sympathetic resonance,” not unlike the experience of having your car windows and rear-view mirror vibrated intensely by extremely loud music in an adjacent vehicle. See the section entitled “Vibralung Acoustics Tutorial” for a more detailed review of the fundamentals of acoustics that are applicable to the Vibralung Acoustical Percussor.


Vibralung Frequencies:

Setting                        Range

L-Low                         55 to 350 Hz

M-Medium                  69 to 660 Hz

H-High                       124 to 1200 Hz

R2 and R5                   5 to 1200 Hz

Note:  The manual erroneously states the Low, Medium, and High as starting at 5 Hz. 

5 Hz is the frequency of the 4 tones plus the pause in one second, which does increase slightly as the frequencies move higher.

Audible Samples of Vibralung Tones


Here are three short samples of Vibralung tones, approximately 60 seconds each, of the sequential note patterns.  The actual treatment sequence consists of 10 minutes of sequential note patterns that gradually increase in frequency from the low end of the selected range to the high end. If you listen carefully to each of these short samples you will hear the repeating pattern of 4 tones (1-2-3-4-1-2-3-4-1-2-3-4, etc) at a tempo of about 360 beats per minute.  Also, you can hear the “step up” frequency shift that occurs roughly every 20 seconds.


The last sample is a 15 second sample of “white noise” or Random Noise (RN).  The Vibralung Acoustical Percussor has two modes for administering Random Noise which is a “hash” of tones generated in the 5 to 1,200 Hz range. R2 and R5 allow operation in Random Noise mode for 2 and 5 minutes, respectively.

Treatment Plan


While the following are recommendations only, they are based on the Vibralung Acoustical Percussor applying principles of sound to the respiratory system. The Vibralung generates three tonal frequency stepping modes, L-Low, M-Medium, and H-High, which are all 10 minute treatment times.


During these modes, at or near sympathetic resonance, the mucus, mucus plugs, and/or the airway surfaces themselves will vibrate, causing the mucus to break away from the airway walls, thin out, and liquefy making it easier for the patient to expel.


Low mode is for larger airways, Medium mode is for middle airways, and High is for smaller airways. Starting with Low will clear the airway path so that mucus cleared further down in the lungs may be expelled as the patient moves to the higher ranges.


Another mode called Random Noise appears to help reduce constriction of the airways to improve breathing. The Vibralung generates frequencies from 5 – 1,200 Hz, which are within the normal range of human speech.

Summary: The tonal settings (L-Low, M-Medium, and H-High) mobilize mucus for airway clearance, and the random noise settings (R2 and R5) relax and open the airways.


Start with the PEP (Positive Expiratory Pressure) valve half open and adjust as needed.

In general, to clear mucus from the airways:


Start with Low followed by R2. Continue these treatments two times per day, generally morning and evening, until the amount of mucus expelled has diminished. Start with Low to create a clear pathway as clearing occurs further into the lungs.


Now treat with Medium followed by R2, or use Low followed by R2 in the morning and Medium followed by R2 in the evening. Continue these treatments two times per day, generally morning and evening, until the amount of mucus expelled has diminished.


Now treat with High followed by R2, or use Low or Medium followed by R2 in the morning and High followed by R2 in the evening. Continue these treatments two times per day, generally morning and evening, until the amount of mucus expelled has diminished.


For most chronic pulmonary conditions, fewer treatments may now be given. It is important to rotate through the Low, Medium and High settings (followed by R2), and to continue to do a few treatments every week or even every month.


In general for bronchoconstriction - asthma:


For conditions such as dry asthma, up to three R5 treatments may be given one after the other for a total of 15 minutes. Such treatments may be administered up to four or five times a day.


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