It is certainly possible, but not as accurate as pulse oximetry. You could look at these: https://ieeexplore.ieee.org/document/7145228 https://ieeexplore.ieee.

It is certainly possible, but not as accurate as pulse oximetry. You could look at these: https://ieeexplore.ieee.org/document/7145228 https://ieeexplore.ieee.org/document/7145228 https://dl.acm.org/doi/abs/10.1145/3360725 https://dl.acm.org/doi/abs/10.1145/3360725