B74-20 Feasibility of a Closed-Loop Acoustic Oscillating Airway Clearance Therapy

Rationale

Regular Airway Clearance Therapies (ACTs) are essential for mechanically removing mucus and trapped bacteria from airways, thereby preventing infections, inflammation, and respiratory complications in muco-obstructive lung diseases. However, patient adherence to ACT remains low due to discomfort and high treatment burden. In this study, we evaluated the early feasibility and patient tolerability of a novel airway clearance device, SonoHeal (Cognita Labs, USA), providing gentle, targeted acoustic oscillations.

Methods

In an IRB-approved study, ten adults (9 female; 7 non-cystic fibrosis bronchiectasis, 2 chronic obstructive pulmonary disease, 1 cystic fibrosis) were enrolled from Ventura County Medical Center and the University of California, Los Angeles. Participants paused routine ACT and bronchodilators for at least 12 hours prior to intervention. Spirometry (Forced Expiratory Volume in one second) and oscillometry-derived respiratory impedance were measured immediately before and after therapy. SonoHeal delivered external acoustic pressure oscillations beginning at 10 Hz in bursts lasting 30 seconds to 2 minutes. Total therapy duration averaged 15.9 minutes and did not exceed 20 minutes. The intervention consisted of two stages. Stage I was exploratory to determine individual tolerability and preferred frequency-amplitude range. In stage II, frequency and amplitude from the patient-selected range were iteratively guided by the device based on the lung impedance progress during each stimulation burst.

Results

Preliminary results (Table 1) demonstrate high satisfaction, high patient acceptance and tolerability, and unanimous preference over existing airway clearance methods. 90% of participants were classified as promoters, leading to a Net Promoter Score of + 80, indicating a strong likelihood of continued use and recommendation. Participants produced measurable sputum expectoration of 6.46g on average within a short treatment duration, suggesting effective mobilization of airway secretions; future evaluations will extend sputum collection up to 30 minutes post-therapy to capture delayed expectoration. Participants with higher sputum output did not consistently demonstrate immediate lung function improvement, suggesting that acute post-treatment fatigue or transient airway instability may mask short-term functional gains. Exploratory correlation analysis suggested that greater sputum expectoration tended to align with greater changes in airway mechanics, although associations were moderate and not statistically significant in this small pilot.

Conclusion

The study showed the successful feasibility of the SonoHeal device as a patient-preferred ACT and demonstrated quantifiable mucus clearance within a short 16-minute therapy. Substantial inter-subject sputum variability suggests that individualized frequency/amplitude tuning may be necessary to optimize airway clearance. Future studies will incorporate a delayed post-treatment lung function assessment to account for fatigue.

This abstract is funded by: National Institutes of Health (NIH)