Saturations above 90% produce very little effect or decrease of arterial oxygen partial pressure (PaO2).
where: HTi : Hypoxic Training index, t : period of time, and SpO2 (t) : SpO2 (%), arterial oxygen saturation value measured at one-second intervals.
This image shows a typical SpO2 curve during a full biofeedback-controlled IHT session.
(FiO2 is altered automatically using biofeedback controlled hypoxicator to attain and sustain the desired SpO2 target value.)
Software is also available[2] to calculate HTi based on readings from a USB connected Pulse Oximeter.