Now that the skin pigmentation problem is known, I’m wondering if there wouldn’t be a rather simple software fix. The light sensor already built into the oximeter should be able to measure the percentage of reflected light at the beginning of a test and then self-calibrate based on that percentage. That might still not produce results as accurate as a blood gas, but I imagine it would be a significant improvement.

This data should be an opportunity for medical equipment manufacturers to update their software.