Evaluation of the robustness of cerebral oximetry to variations in skin pigmentation using a tissue-simulating phantom

Clinical studies have demonstrated that epidermal pigmentation level can affect cerebral oximetry measurements. To evaluate the robustness of these devices, we have developed a phantom-based test method that includes an epidermis-simulating layer with several melanin concentrations and a 3D-printed cerebrovascular module. Measurements were performed with neonatal, pediatric and adult sensors from two commercial oximeters, where neonatal probes had shorter source-detector separation distances. Referenced blood oxygenation levels ranged from 30 to 90%. Cerebral oximeter outputs exhibited a consistent decrease in saturation level with simulated melanin content; this effect was greatest at low saturation levels, producing a change of up to 15%. Dependence on pigmentation was strongest in a neonatal sensor, possibly due to its high reflectivity. Overall, our findings indicate that a modular channel-array phantom approach can provide a practical tool for assessing the impact of skin pigmentation on cerebral oximeter performance and that modifications to algorithms and/or instrumentation may be needed to mitigate pigmentation bias. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

Clinical studies have shown that epidermal pigmentation can affect cerebral oximetry measurements. Researchers have developed a phantom-based test method to evaluate the impact of skin pigmentation on cerebral oximeter performance. The findings indicate that cerebral oximeter outputs exhibit a consistent decrease in saturation level with simulated melanin content, with the effect being greatest at low saturation levels and most pronounced in neonatal sensors.