What is the normal value for a pulse oximeter?

　　The main parameters measured by a pulse oximeter are pulse rate, blood oxygen saturation, and perfusion index. Under normal circumstances, the normal range for blood oxygen saturation measured by a pulse oximeter is usually between 95% and 100%, while the normal ranges for pulse rate and perfusion index are generally 60–100 beats per minute and 4–5, respectively. If any abnormalities are detected, timely medical consultation is recommended. Detailed explanations are as follows:

　　The blood oxygen saturation measured by a pulse oximeter generally refers to arterial oxygen saturation, with a normal range typically between 95% and 100%, reflecting the efficiency of oxygen inhalation by the lungs and its binding with hemoglobin. In individuals with respiratory diseases, cardiovascular conditions, or those in low-oxygen environments such as high altitudes, blood oxygen saturation levels may be reduced.

　　In addition to blood oxygen saturation, pulse oximeters may also measure pulse rate and perfusion index. The normal pulse rate range for adults is 60–100 beats per minute. The normal range for perfusion index is generally 4–5, and it can be influenced by multiple factors, such as the measurement site and the patient's blood perfusion status. A low value may indicate poor blood perfusion, whereas a high value may suggest adequate oxygen supply.

　　When using a pulse oximeter, ensure correct operation, appropriate measurement site selection, and avoid interference factors such as ambient light and nail color that may affect measurement accuracy.