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Journal of Biomedical Optics • Open Access

Relations between ac-dc components and optical path length in photoplethysmography
Author(s): Chungkeun Lee; Hang Sik Shin; Myoungho Lee

Paper Abstract

Photoplethysmography is used in various areas such as vital sign measurement, vascular characteristics analysis, and autonomic nervous system assessment. Photoplethysmographic signals are composed of ac and dc, but it is difficult to find research about the interaction of photoplethysmographic components. This study suggested a model equation combining two Lambert-Beer equations at the onset and peak points of photoplethysmography to evaluate ac characteristics, and verified the model equation through simulation and experiment. In the suggested equation, ac was dependent on dc and optical path length. In the simulation, dc was inversely proportionate to ac sensitivity (slope), and ac and optical path length were proportionate. When dc increased from 10% to 90%, stabilized ac decreased from 1 to 0.89 ± 0.21, and when optical path length increased from 10% to 90%, stabilized ac increased from 1 to 1.53 ± 0.40.

Paper Details

Date Published: 1 July 2011
PDF: 5 pages
J. Biomed. Opt. 16(7) 077012 doi: 10.1117/1.3600769
Published in: Journal of Biomedical Optics Volume 16, Issue 7
Show Author Affiliations
Chungkeun Lee, Yonsei Univ. (Korea, Republic of)
Hang Sik Shin, Yonsei Univ. (Korea, Republic of)
Myoungho Lee, Yonsei Univ. (Korea, Republic of)

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