City Research Online

Abstract

Despite the clinical importance of pulse oximetry, the precise nature of the interaction of light with tissue, which underlies the technique, is not yet fully understood. The limitations of the method with regard toits accuracy inconditions of compromised perfusion and/or low blood oxygen saturations are well documented but have only partly been resolved. Results from a static monolayer Monte Carlo modelof optical path and reflectance attwo wavelengths most commonly usedinpulse-oximetry (660 and 940 nm) through skin tissue, containing different volume fractions of blood witharange of oxygen saturations, are presented. Results exhibited differences in mean optical path (MOP) between the two wavelengths, with differences generally increasing with increasing tissue oxygen saturation and decreasing blood volume.As anexample, inatypical sensor configuration, the MOP of red light traveling through skin containing 7.5% blood volume fraction with mean oxygen saturationof60% was 58% higher than that for infrared. The results presented should contribute to further understandingofthe effectofphysiological conditions suchasanemia, ischemia and hypoxemia on the accuracy of pulse oximetry readings.

Publication Type:	Article
Additional Information:	This is an author-created, un-copyedited version of an article accepted for publication in Biomedical Physics & Engineering Express. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/2057-1976/2/6/065018.
Publisher Keywords:	Pulse oximetry, Monte Carlo, light tissue interaction, clinical applications
Subjects:	R Medicine > RC Internal medicine T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments:	School of Science & Technology > Engineering
SWORD Depositor:	Symplectic Administrator

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