In vivo absorption spectroscopy for absolute measurement.

Area of Science:

• Biomedical Optics
• Spectroscopy
• Physiological Monitoring

Background:

• In vivo spectroscopy is affected by individual variations in tissue scattering and concentration.
• Current methods often rely on statistical calibration curves, which can be inaccurate due to inter-subject variability.

Purpose of the Study:

• To develop a novel in vivo spectroscopy method for determining absolute substance concentration.
• To eliminate the need for statistical calibration curves by accounting for individual differences in scattering and concentration.
• To simplify and improve the accuracy of in vivo measurements.

Main Methods:

• Proposed a novel spectroscopic method to derive absolute substance concentration.
• Applied the method to in vivo absorption spectroscopy using reflectance measurements in retinal vessels.
• Validated the method using tissue phantoms with varying absorbance and scattering properties.

Main Results:

• The developed method provides absolute substance concentration values independent of individual subject variations.
• Successfully monitored oxygen saturation levels in retinal vessels.
• Demonstrated robustness across a range of absorbance values and scattering efficiencies in phantom studies.

Conclusions:

• The proposed method significantly reduces challenges in in vivo spectroscopic measurements.
• Offers a more accurate and universally applicable approach for determining substance concentrations in biological tissues.
• Has potential applications in physiological monitoring and clinical diagnostics.