Smartphone camera oximetry in an induced hypoxemia study

With these results, we can start to imagine replacing purpose-built medical devices, such as pulse oximeters, with software running on the phone using its more general-purpose sensors. Image credit: Dennis Wise/University of Washington

Abstract

Hypoxemia, a medical condition that occurs when the blood is not carrying enough oxygen to adequately supply the tissues, is a leading indicator for dangerous complications of respiratory diseases like asthma, COPD, and COVID-19. While purpose-built pulse oximeters can provide accurate blood-oxygen saturation (SpO2) readings that allow for diagnosis of hypoxemia, enabling this capability in unmodified smartphone cameras via a software update could give more people access to important information about their health. Towards this goal, we performed the first clinical development validation on a smartphone camera-based SpO2 sensing system using a varied fraction of inspired oxygen (FiO2) protocol, creating a clinically relevant validation dataset for solely smartphone-based contact PPG methods on a wider range of SpO2 values (70–100%) than prior studies (85–100%). We built a deep learning model using this data to demonstrate an overall MAE = 5.00% SpO2 while identifying positive cases of low SpO2 < 90% with 81% sensitivity and 79% specificity. We also provide the data in open-source format, so that others may build on this work.

Publication
in npj Digital Medicine
Jason S. Hoffman
Jason S. Hoffman
PhD Student Researcher

My research interests include health sensing, machine learning and healthcare access.

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