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Updated: Jul 17, 2026
09:54
A Model to Simulate Clinically Relevant Hypoxia in Humans
Published on: December 22, 2016
Relation between hematocrit and optical density in pulse oximetry -In vitro study with Waseda mock circulatory
H Suzaki1, S Takeda, N Kobayashi
1School of Science and Engineering, Waseda University, 3-4-1 Ohkubo Shinjuku-ku, Tokyo, Japan; Nihon Kohden Corp., 6-2-20 Fujimi Tsurugashima-shi, Saitama, Japan.
Summary
This study clarifies the optical properties of blood, essential for developing new biooptic instruments. Findings reveal how blood
Area of Science:
- Biomedical Optics
- Biophotonics
- Tissue Optics
Background:
- Optical properties of living tissues remain poorly understood, necessitating empirical formulas for biooptic instrumentation.
- Pulsating blood perfusion in tissues presents unique challenges for optical measurements.
- Accurate optical models are crucial for advancing medical imaging and diagnostics.
Purpose of the Study:
- To investigate the relationship between whole blood optical density (O.D.) and hematocrit.
- To evaluate theoretical models for predicting blood optical properties under simulated circulatory conditions.
- To establish a foundation for more precise biooptic instrumentation.
Main Methods:
- Utilized transmission spectrophotometry to measure whole blood optical density.
- Employed the Waseda mock circulatory system to simulate tissue blood perfusion.
- Analyzed data across multiple wavelengths (660, 805, 940, and 1300 nm).
Main Results:
- Optical density per unit light path length stabilized with increasing path length for each hematocrit.
- Twersky's, Loewinger's, and photon diffusion equations accurately predicted O.D.-hematocrit relationships at 660, 805, and 940 nm.
- Loewinger's equation provided the best fit for predicting O.D.-hematocrit data at 1300 nm.
Conclusions:
- Established a quantitative relationship between blood optical density and hematocrit.
- Validated theoretical models for optical properties of blood, improving predictive accuracy.
- Provided critical data for the development of advanced biooptic instruments for tissue analysis.
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