It is a small device that measures the oxygen present in the patient’s blood, along with the pulse rate. Pulse Oximeter gives continuous and instantaneous arterial hemoglobin saturation. This oxygen ratio in the blood plays an important role in the diagnosis of doctors. Therefore, these data should be obtained easily and precisely. There are two general methods of obtaining these data; The first of these is the classical method of bloodletting, which is difficult, painful and does not give the necessary clear results. As you know, this is based on taking blood by inserting the appropriate needle into the right vein in the right place. The second method is to use an oximeter.