Fig 1.
Inhaler recording setup.
Fig 2.
Example of inhaler inhalation audio and flow signals.
(A) inhaler inhalation audio signal with estimated acoustic envelope and (B) corresponding flow signal.
Table 1.
Participant information and baseline lung function (mean ± standard deviation).
Table 2.
Mean (± standard deviation) of flow parameter values from recorded inhalation flow signals averaged across all participants.
Fig 3.
Examples of actual and estimated inhaler inhalation flow profiles.
(A) High, (B) Medium and (C) Low flow rates. The vertical lines represent the actual and estimated Tr values.
Fig 4.
Average audio-based flow estimation errors.
(A) Averageerror, (B) PIFRerror, (C) ICerror and (D) Trerror (%) (± standard error). Results are divided into models calibrated using high, medium and low flow inhalation recordings and tested on high, medium and low flow ranges.
Fig 5.
Boxplots representing the median, interquartile range and 1.5×interquartile range of regression coefficients.
(A) a and (B) b regression coefficients where *p<0.05 and **p<0.01 corrected for multiple comparisons using Bonferroni correction.
Fig 6.
Average accuracy (%) of inhalation flow profile parameter estimation across all flow rates at different SNR levels.