>monopoly on blood oxygen measurement in a wearable electronic device

And I know this isn't your argument, but that's a VERY narrow market for the purposes of a US inquiry into monopolies. Like, the normal market definition fights are about whether you should be considering "premium smartphones" or "smartphones" as a whole. Or all of the grocery stores in a given region, and whether that should include convenience stores that also sell groceries.

I'd be hard pressed to imagine a court really contemplating an argument that a company has a monopoly in a very small slice of a market. It would be like saying that Rolex has a monopoly in luxury sport watches with headquarters in Geneva.