Novel diffuse Optical method to combat skin color bias in non-invasive optical biomarker sensing devices such as pulse oximeters

Introduction

During COVID-19, skin color bias in Optical Biomarkers Sensing (OBS) devices (e.g., pulse oximeter) was suspected to have contributed to the loss of lives in darkly pigmented people. The Continuous Wave (CW) technology used in these devices is limited in accuracy, and results are biased by skin color and light scattering in tissue.

Project Overview

NOBIAS aims to break through frontiers to create foundational multilayer fast Time Domain Diffuse Optical Spectroscopy (TDDOS) to eliminate color bias and inaccuracy shortcomings of current CW technology and revolutionize the future of bias-free, accurate optical biomarker sensing.

Objectives

To achieve this ambition, NOBIAS will:

1. Create a multilayer TDDOS dynamic skin tissue model based on Monte Carlo to investigate the effect of skin type and anatomy on color bias.
2. Optimize the concept, device, and probe design to compensate for and eliminate color bias and inaccuracies (WP1, Obj.1).

Methodology

Two groundbreaking approaches are envisioned:

1. An intermediate hybrid CW-TDDOS fusion approach (phase 1) to compensate for skin color bias.
2. An ambitious new frontier fast TDDOS approach (phase 2) to eliminate color bias (WP2, Obj.2) and provide faster (100-250X), real-time measurements at wearable footprint (100X).

Compensation Algorithm

A first-of-a-kind compensation algorithm based on real-time instrument response function (IRF) and phantom arm aims to deliver groundbreaking accuracy (14X) (WP3, Obj.3). Early benchtop testing and feedback across work packages will mitigate risks of ambitious objectives.

Validation

NOBIAS paradigm device/algorithm will be validated on tissue-mimicking phantoms, and bias-free sensing will be demonstrated on blood biomarkers (hemoglobin (Hb, HbO), oxygen saturation (StO2, SpO2)) sensing at the wrist location on healthy:

• i) adults
• ii) infants (WP4, Obj.4).

Conclusion

NOBIAS breakthrough lays the foundation for the world's first bias-free and accurate OBS devices and sets its legacy to be the gold standard for bias-free clinical and personal biomarkers sensing applications.