Oximeter is to detect blood oxygen, oximeter monitoring blood oxygen is a non-invasive operation, can effectively monitor the situation of blood oxygen in the body, and play a key role in predicting the changes of the disease, mainly finger finger pulse oxygen as the monitoring index. If there is atherosclerosis or vascular blockage, lipid deposition in the vascular cavity, poor peripheral blood circulation, easily lead to hypoxia, the use of oximetry to know the blood oxygen content also indirectly reflects the cardiovascular and cerebrovascular pathology, as soon as possible to improve the coronary angiography and cerebral angiography examination can understand the situation, you can develop a reasonable treatment plan to prevent myocardial infarction and cerebral infarction. At the same time, it should be noted that long-term clamping of finger pulse oxygen is easy due to local compression or cold weather, and affect the blood circulation at the end of the finger, resulting in misjudgment, can be soaked in warm water and then re-monitoring to improve the accuracy of detection.