Type

Journal Article

Authors

Richard B Reilly
Richard W Costello
Anne Marie Healy
Carsten Ehrhardt
Shona D'Arcy
Peter O'Connell
Jansen N Seheult
Martin S Holmes

Subjects

Engineering

Topics
relative humidity energy drug delivery exhalation acoustic monitoring patients size acoustic

An Acoustic-Based Method to Detect and Quantify the Effect of Exhalation into a Dry Powder Inhaler. (2014)

Abstract Abstract Background: Dry powder inhaler (DPI) users frequently exhale into their inhaler mouthpiece before the inhalation step. This error in technique compromises the integrity of the drug and results in poor bronchodilation. This study investigated the effect of four exhalation factors (exhalation flow rate, distance from mouth to inhaler, exhalation duration, and relative air humidity) on dry powder dose delivery. Given that acoustic energy can be related to the factors associated with exhalation sounds, we then aimed to develop a method of identifying and quantifying this critical inhaler technique error using acoustic based methods. Methods: An in vitro test rig was developed to simulate this critical error. The effect of the four factors on subsequent drug delivery were investigated using multivariate regression models. In a further study we then used an acoustic monitoring device to unobtrusively record the sounds 22 asthmatic patients made whilst using a Diskus(™) DPI. Acoustic energy was employed to automatically detect and analyze exhalation events in the audio files. Results: All exhalation factors had a statistically significant effect on drug delivery (p<0.05); distance from the inhaler mouthpiece had the largest effect size. Humid air exhalations were found to reduce the fine particle fraction (FPF) compared to dry air. In a dataset of 110 audio files from 22 asthmatic patients, the acoustic method detected exhalations with an accuracy of 89.1%. We were able to classify exhalations occurring 5 cm or less in the direction of the inhaler mouthpiece or recording device with a sensitivity of 72.2% and specificity of 85.7%. Conclusions: Exhaling into a DPI has a significant detrimental effect. Acoustic based methods can be employed to objectively detect and analyze exhalations during inhaler use, thus providing a method of remotely monitoring inhaler technique and providing personalized inhaler technique feedback.
Collections Ireland -> Royal College of Surgeons in Ireland -> PubMed

Full list of authors on original publication

Richard B Reilly, Richard W Costello, Anne Marie Healy, Carsten Ehrhardt, Shona D'Arcy, Peter O'Connell, Jansen N Seheult, Martin S Holmes

Experts in our system

1
Richard Reilly
Trinity College Dublin
Total Publications: 183
 
2
Richard W Costello
Royal College of Surgeons in Ireland
Total Publications: 62
 
3
Anne Marie Healy
Trinity College Dublin
Total Publications: 85
 
4
Shona D'Arcy
Royal College of Surgeons in Ireland
Total Publications: 12
 
5
Jansen N Seheult
Royal College of Surgeons in Ireland
Total Publications: 15
 
6
Martin S Holmes
Royal College of Surgeons in Ireland
Total Publications: 12