An algorithm for the detection of individual breaths from the pulse oximeter waveform.
OBJECTIVE
To determine if wavelet analysis techniques can be used to reliably identify individual breaths from the photoplethysmogram (PPG).


METHODS
Photoplethysmograms were obtained from 22 healthy adult volunteers timing their respiration rate in synchronisation with a metronome. A secondary timing signal was obtained by asking the volunteers to actuate a small push button switch, held in their right hand, in synchronisation with their respiration. Each PPG was analyzed using primary wavelet decomposition and two new, related, secondary decompositions to determine the accuracy of individual breath detection.


RESULTS
The optimal breath capture was obtained by manually polling the three techniques, allowing detection of 466 out of the 472 breaths studied; a detection rate of 98.7% with no false positive breaths detected.


CONCLUSIONS
Our technique allows the accurate capture of individual breaths from the photoplethysmogram, and leads the way for developing a simple non-invasive combined respiration and saturation monitor.
Leonard
Paul
P
Department of Accident and Emergency Medicine, The Royal Hospital for Sick Children, Sciennes Rd, Edinburgh, EH9 1LF, Scotland, UK. paul_leonard@blueyonder.co.uk
Grubb
Neil R
NR
Addison
Paul S
PS
Clifton
David
D
Watson
James N
JN
D000465:Algorithms; D006801:Humans; D010092:Oximetry / Q000379:methods*; D017156:Photoplethysmography; D012016:Reference Values; D015203:Reproducibility of Results; D012119:Respiration; D012680:Sensitivity and Specificity