A pulse oximeter is used to noninvasively measure blood oxygen saturation, or SpO2, and pulse rate. Its uses include monitoring patients with respiratory conditions like asthma and COPD, assessing breathing difficulty during surgery or illness, tracking the effectiveness of ventilators or oxygen therapy, and screening for issues like congenital heart disease in newborns. It is also used for general health monitoring, recovery assessment, and detecting conditions like sleep apnea, becoming a standard tool in critical care and home health settings