Not in significant quantities. Another study also using Far-UV excimer lamps [1] measured levels of less than 0.005 ppm, which is far below the 0.05 ppm maximum allowed by the FDA for medical devices [2].
Nice explanation! May I suggest a tiny addition to the text? Fixed point (in decimal) is also useful to make sure 1 trillion dimes are 100 billion dollars instead of $99,999,997,952.
> Blood oxygen monitors, or pulse oximeters, are considered Class II medical devices by the FDA. Generally, any company that wants to sell one in the United States has to submit documentation to the agency confirming that its product works just as well as other versions of the same product already on the market. There’s a workaround, though: if the company says that the product is just for fun, or for general “wellness,” they don’t have to go through that process. They can’t claim that it can diagnose or treat any medical conditions, but they can put it up for sale.
You might still use that as a cue that you should get tested for sleep apnea, but the watch itself isn't considered a medical device for measuring blood oxygen.
That seems like a typo. The title says “opposite”, and just before specifying 45 degrees, the article says the layers are at a “right angle” to one another. Looking at their other products, they seem to differentiate on bonding strength and surfacing, which is pretty common.
