2022-09-19 カリフォルニア大学サンディエゴ校(UCSD)
スマートフォンは、血中酸素飽和度70%まで検知できることが実証実験で明らかになりました。これは、米国食品医薬品局(FDA)が推奨する、医療現場で使用される小型の酸素濃度測定器「パルスオキシメーター」が測定可能な最低値である。
新手法では、参加者が指先をスマートフォンのカメラとフラッシュの上に置き、研究チームが訓練したディープラーニングアルゴリズムを使って、血中酸素濃度を解読する。
研究チームは、6人の被験者に酸素と窒素の混合ガスを投与し、人為的に血中酸素濃度を下げたところ、スマートフォンは80%の確率で被験者の血中酸素濃度が低いかどうかを正しく予測した。
<関連情報>
- https://today.ucsd.edu/story/a-smartphones-camera-and-flash-could-help-people-measure-blood-oxygen-levels-at-home
- https://www.nature.com/articles/s41746-022-00665-y
スマートフォンカメラを用いた低酸素症誘発試験におけるオキシメトリ Smartphone camera oximetry in an induced hypoxemia study
Jason S. Hoffman,Varun K. Viswanath,Caiwei Tian,Xinyi Ding,Matthew J. Thompson,Eric C. Larson,Shwetak N. Patel & Edward J. Wang
npj Digital Medicine Published:19 September 2022
DOI:https://doi.org/10.1038/s41746-022-00665-y
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.
