Adenosine triphosphate (ATP) is the biochemical way to store and use energy. F or your muscles -- in fact, for every cell in your body -- the source of energy that keeps everything going is called ATP.
An approximate blood oxygen level can also be estimated using a pulse oximeter â a small device that clips on your finger. Though the pulse oximeter actually measures the saturation of oxygen in your blood, the results are often used as an estimate of blood oxygen levels.Normal pulse oximeter readings range from 95 to 100 percent, under most circumstances. Values under 90 percent are considered low.1  Causes.n approximate blood oxygen level can also be estimated using a pulse oximeter â a small device that clips on your finger. Though the pulse oximeter actually measures the saturation of oxygen in your blood, the results are often used as an estimate of blood oxygen levels.
Normally, a PaO2 reading below 80 mm Hg or a pulse ox below 95 percent is considered low. Itâs important to know what is normal for you, especially if you have a chronic lung condition. Your doctor can provide recommendations as to what ranges of oxygen levels are acceptable for you.