Optical density based quantification of total haemoglobin concentrations with spectroscopic optical coherence...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Hematology

Background:

• Spectroscopic optical coherence tomography (sOCT) is a developing technology for non-invasive quantification of total hemoglobin concentrations ([tHb]).
• Previous sOCT methods achieved limited precision (9.10 g/dL), with improvements to 3.80 g/dL using focus tracking and zero-delay acquisition (FZA).
• Clinical relevance requires sOCT precision of at least 2.0 g/dL.

Purpose of the Study:

• To enhance the precision of sOCT for total hemoglobin ([tHb]) measurements.
• To develop a new analysis method based on optical density (OD) optimization to reduce variability in [tHb] estimations.
• To validate the improved method using ex-vivo flowing whole-blood samples.

Main Methods:

• Implemented a numerical optimization of optical density (OD) to retrieve [tHb] content, simplifying the Lambert-Beer fitting process.
• Considered the blood absorption flattening effect within the OD-based model.
• Validated the model against a commercial blood analyzer using ex-vivo whole-blood samples with [tHb] in the clinical range (7-23 g/dL).

Main Results:

• The OD-based approach with conventional sOCT achieved a precision of 3.09 g/dL and a bias of 0.86 g/dL.
• Combining the OD methodology with focus tracking and zero-delay acquisition (FZA) further improved precision to 2.08 g/dL with a bias of 0.46 g/dL.
• These results demonstrate significant improvements in sOCT precision for [tHb] quantification.

Conclusions:

• The developed optical density optimization method substantially increases the precision of sOCT for non-invasive total hemoglobin ([tHb]) measurement.
• The combination of OD methodology and FZA achieves precision levels relevant for clinical applications.
• This advanced sOCT analysis method holds promise for improved diagnostic capabilities in hematology.