An acoustic method to automatically detect pressurized metered dose inhaler actuations

Area of Science:

• Pulmonary Medicine
• Biomedical Engineering
• Acoustic Signal Processing

Background:

• Chronic respiratory diseases like asthma and COPD affect over 400 million globally and are incurable.
• Pressurized metered dose inhalers (pMDIs) are widely used but require precise user coordination for effective drug delivery.
• Poor inhaler technique significantly reduces therapeutic efficacy and disease symptom control.

Purpose of the Study:

• To investigate the clinical potential of a noninvasive acoustic method for monitoring pMDI actuation coordination.
• To develop and validate an algorithm for detecting actuation sounds using a portable monitoring device.
• To assess the accuracy of acoustic monitoring in healthy individuals and patients with respiratory diseases.

Main Methods:

• A portable device was developed to capture actuation sounds from pMDIs.
• Acoustic data were collected from 158 actuations across 5 healthy subjects and 15 patients with respiratory diseases.
• A specialized algorithm was employed to analyze the acoustic signals and detect actuation events.

Main Results:

• The developed algorithm achieved an overall accuracy of 99.7% in detecting pMDI actuation sounds.
• The acoustic monitoring method demonstrated high precision in distinguishing correct from incorrect inhaler actuations.
• The study confirmed the feasibility of using acoustic signals for assessing inhaler technique.

Conclusions:

• Noninvasive acoustic monitoring shows significant clinical potential for evaluating pMDI actuation coordination.
• This technology can provide informative feedback to improve patient inhaler technique and enhance respiratory disease management.
• The developed system may serve as a valuable tool in clinical training for optimizing inhaled therapy.