Comparing PEP Therapy Devices: Positive Expiratory Pressure, Airway Vibration, and High Frequency Oscillation

Mucus buildup and breathing difficulties are daily challenges for people living with chronic lung conditions. Positive Expiratory Pressure (PEP) therapy provides a simple yet effective way to help clear mucus and support better lung function.1,2,3 Choosing the right PEP device is key, as each works differently and requires varying levels of patient effort.

In this article, we’ll compare traditional devices like EzPAP, Aerobika, and Acapella to multi-therapy systems like BiWaze® Clear, an electronically controlled PEP system that delivers consistent therapy with digital pressure settings, electronically regulated flow, and integrated high-frequency oscillation and vibrating mesh aerosol delivery.4,5,6,7

How positive expiratory pressure therapy works to keep airways open and improves lung ventilation.

What is PEP Therapy?

Positive expiratory pressure therapy is a non-invasive airway clearance technique. The therapy generates a back pressure during exhalation, sometimes combined with oscillations that loosen secretions.2,9

Patients exhale against resistance, which helps:

  • Keep airways open
  • Loosen and mobilize mucus
  • Improve lung ventilation

 

PEP therapy is commonly prescribed for conditions such as:

  • COPD (Chronic Obstructive Pulmonary Disease)
  • Bronchiectasis
  • Cystic Fibrosis
  • Pneumonia

 

Therapy sessions usually last 10–20 minutes and can be performed at home, making it convenient for long-term care.1,9 Regular use is important for maintaining consistent results.

Patients are encouraged to incorporate PEP therapy into their daily routines, therefore selecting an effective PEP device is critical. Consistency is key to experiencing long-term benefits.1,2

 

What Are the Types of PEP Devices?

PEP Valve (Traditional PEP)
Basic resistance devices (e.g., EzPAP) primarily used in the hospital setting.
Oscillating PEP (OPEP)
Combine resistance with vibrations to loosen mucus (e.g., Acapella, Aerobika).2,10

Electronically Controlled PEP
Deliver digitally set expiratory pressure with electronically regulated flow (e.g., BiWaze Clear).4,7

OPEP devices like the Aerobika, and Acapella are widely prescribed but do not offer patients the ability to deliver precise, electronically controlled PEP. Traditional PEP and OPEP devices also do not integrate aerosol delivery, requiring separate equipment. BiWaze Clear delivers oscillating lung expansion (OLE) therapy, combining high-frequency oscillation, electronically controlled PEP, and vibrating mesh aerosol delivery into a single therapy session.4,5,6,11

 

How the Devices Work

  • PEP valves (EzPAP): Basic resistance devices that are effective but fully dependent on patient effort.
  • Oscillating PEP (Acapella, Aerobika): Generate vibrations to help break up mucus, but still effort dependent.2,10
  • BiWaze® Clear: An electronically controlled PEP system that senses exhalation, then delivers consistent, repeatable expiratory pressure. It integrates high-frequency oscillation and vibrating mesh aerosol delivery, three therapies in a single 10-minute session.4,5,6,7

 

Comparison Matrix

 
Example Devices / Type of PEPEzPAP (Traditional PEP)Acapella / Aerobika (OPEP)BiWaze® Clear
MechanismBasic resistance valveCounterweight in plastic housing creates oscillationsElectronically controlled PEP with digital pressure settings & regulated flow
Consistency of PressurePatient-effort dependentVariable, based on techniqueConsistent, repeatable digitally set expiratory pressure
Oscillation / Vibration Not available✔️ Vibration (inconsistent)✔️ Electronically delivered oscillations (consistent)
Nebulization Included Requires separate device Requires separate device✔️ Integrated vibrating mesh aerosol delivery
Patient Effort RequiredHighModerateLow – electronically controlled delivery reduces patient effort
Best Used ForPatients with strong effort and simple needsPatients who tolerate oscillation effortCOPD, bronchiectasis, pneumonia, or patients needing consistent airway clearance
Designed for Mucus Clearance✔️ If used correctly✔️ With added oscillations✔️ Supports consistent mucus clearance
LimitationsTechnique dependentEffort dependent, no aerosol integrationRequires power source to charge built-in battery

 

Key Advantages Electronically Controlled PEP

  • Consistency & Accuracy
    Traditional PEP devices depend on patient effort, which can lead to variable results. BiWaze Clear uses digital pressure settings and electronically regulated flow to deliver consistent, repeatable therapy.4,6
  • Integrated Therapy Options
    Combines electronically controlled PEP, high-frequency oscillation, and vibrating mesh aerosol therapy. Patients often complete all three in ~10 minutes compared to >30 minutes with separate devices.4,7
  • Therapy Personalization
    Adjustable settings support a wide range of patient needs, including PEP therapy for COPD, bronchiectasis, cystic fibrosis, or supportive therapy for pneumonia.

Conclusion

Traditional PEP and OPEP devices like EzPAP, Aerobika, and Acapella remain commonly used for airway clearance, but they rely heavily on patient effort, are variable based on patient effort, and require separate devices for aerosol delivery. BiWaze Clear represents a different approach, providing electronically controlled PEP with integrated high-frequency oscillation and vibrating mesh aerosol therapy.

Ready to see how BiWaze Clear can support your patients’ respiratory therapy? Contact us today to learn more.

Home PEP therapy with BiWaze Clear for COPD, bronchiectasis, cystic fibrosis.

Frequently Asked Questions

How does an oscillating PEP device differ from BiWaze Clear?
Oscillating devices like Acapella and Aerobika create vibrations but still depend on patient effort. BiWaze Clear electronically delivers controlled pressure and oscillations, reducing variability.

Can a PEP device help clear mucus?
Yes. PEP therapy devices are designed to loosen mucus so it can be coughed out. BiWaze Clear supports more consistent therapy delivery with electronically controlled settings.

Can people with COPD or bronchiectasis use a PEP device?
Yes. PEP therapy is widely used for COPD, bronchiectasis, cystic fibrosis, and pneumonia. BiWaze Clear’s electronically controlled pressure and oscillation may be especially helpful for patients with variable lung function.

Can PEP therapy be combined with other treatments?
Traditional devices usually focus only on resistance breathing. BiWaze Clear integrates PEP, oscillation, and aerosol therapy into a single 10-minute session, saving patients time and effort.

Can I use a nebulizer with traditional oscillating PEP (OPEP) devices like Acapella or Aerobika?
Traditional OPEP devices such as Acapella and Aerobika are designed for mucus clearance but do not include integrated aerosol therapy. To deliver nebulized medication, patients typically need a separate nebulizer system (jet or vibrating mesh). This often means completing two separate treatments, one for airway clearance and one for aerosol delivery, taking 20-30 minutes or more.

How does BiWaze Clear integrate nebulizer therapy differently?
BiWaze Clear has a built-in vibrating mesh nebulizer. This allows aerosolized medication delivery at the same time as PEP and high-frequency oscillations (HFO). Patients can complete three therapies in one 10-minute session, PEP, oscillation, and aerosol delivery—, educing treatment burden and supporting adherence.

Is there evidence that integrated nebulization with BiWaze Clear is more effective?
Yes. An independent in vitro study conducted by Rob DiBlasi and colleagues from Seattle Research Institute compared aerosol delivery efficiency across Oscillating Lung Expansion (OLE) systems with integrated nebulizers. Results showed that BiWaze Clear delivered significantly greater aerosol deposition compared with other devices. This suggests that BiWaze Clear’s integration of vibrating mesh aerosol with consistent, electronically controlled PEP and oscillation may provide patients with more efficient and reliable medication delivery during airway clearance sessions.6

Why does combining PEP, oscillation, and nebulization matter for patients?
Combining these therapies reduces the overall time required for daily treatments while ensuring consistent airway clearance and medication delivery. For patients with COPD, bronchiectasis, or cystic fibrosis, who may need multiple therapies daily, this integration can improve adherence and quality of life by streamlining therapy into a single session.

Which patients may benefit most from BiWaze Clear’s integrated nebulizer?
Patients who:

  • Require both airway clearance and nebulizer therapy (e.g., bronchodilators, antibiotics).
  • Experience fatigue or reduced adherence due to long daily treatment times.
  • Need consistent and reliable pressure/oscillation delivery regardless of effort.
  • Have conditions like COPD, bronchiectasis, or cystic fibrosis where combined therapy is standard.

References

  1. McIlwaine MP, Button B, Dwan K. Positive expiratory pressure physiotherapy for airway clearance in people with cystic fibrosis. Cochrane Database Syst Rev. 2015;2015(6):CD003147. doi:10.1002/14651858.CD003147.pub4
  2. Lee AL, Burge AT, Holland AE. Airway clearance techniques for bronchiectasis. Cochrane Database Syst Rev. 2015;2015(11):CD008351. doi:10.1002/14651858.CD008351.pub3
  3. Strickland SL, Rubin BK, Drescher GS, et al. AARC clinical practice guideline: effectiveness of nonpharmacologic airway clearance therapies in hospitalized patients. Respir Care. 2013;58(12):2187-2193. doi:10.4187/respcare.02925
  4. Huynh TT, Liesching TN, Cereda M, et al. Efficacy of oscillation and lung expansion in reducing postoperative pulmonary complication. J Am Coll Surg. 2019;229(5):458-466.e1. doi:10.1016/j.jamcollsurg.2019.06.003
  5. Williams CD, Holbrook KM, Shiari A, et al. Effect of oscillation and pulmonary expansion therapy on pulmonary outcomes after cardiac surgery. J Respiration. 2024;4(2):91-101. doi:10.3390/jor4020009
  6. Kontoudios N, KenKnight H, DiBlasi RM. In vitro comparison of aerosol delivery in high-frequency assisted airway clearance devices with integrated nebulizers. Respir Care. Published online August 2024. doi:10.4187/respcare.11988
  7. Feng Z, Han Z, Wang Y, Guo H, Liu J. Comparison of vibrating mesh and jet nebulizers in chronic obstructive pulmonary disease: a systematic review and meta-analysis. Int J Chron Obstruct Pulmon Dis. 2024;19:829-839. doi:10.2147/COPD.S418703
  8. Volsko TA, Chatburn RL. Airway clearance therapy: finding the evidence. Respir Care. 2011;56(12):1916-1927. doi:10.4187/respcare.01452
  9. McIlwaine MP, Alarie N, Davidson GF, et al. Long-term multicenter randomized controlled study of high-frequency chest wall oscillation versus positive expiratory pressure mask in cystic fibrosis. Thorax. 2013;68(8):746-751. doi:10.1136/thoraxjnl-2012-202915
  10. Alghamdi SM, Almajid FM, Alotair H, et al. Oscillatory positive expiratory pressure therapy in COPD: a randomized controlled trial. Int J Chron Obstruct Pulmon Dis. 2017;12:859-865. doi:10.2147/COPD.S122505
  11. DiBlasi RRT-NPS, Kontoudios RRT, KenKnight BS. Assessment of Oscillatory Pressure and Flow Waveforms with the BiWaze® Clear System: An In Vitro Study in Spontaneous Breathing Models. ABMRC; 2025. Accessed April 2025.

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