Notwithstanding agreeing I suspect this is one of the grandfathered in things. Calibration is pretty big in this, the watch methods have massive epidemiological

Notwithstanding agreeing I suspect this is one of the grandfathered in things. Calibration is pretty big in this, the watch methods have massive epidemiological evidence behind them but it remains a model, and with issues around skin colour (tattoos) which also dogs finger clamp O2 meters. People often say if we invented beer now, the FDA would forbid it.