The second application to be discussed is a pulse oximeter. The pulse oximeter measures the amount of oxygen in the blood and extracts the heart rate. It is used to determine how well oxygen is saturated in the blood. Typically the desired result is 100% oxygen saturation for a healthy person, or in the high 90% range. If the percentage is much lower than that, it is an indication of a possible problem in getting oxygen into the blood cells and spread properly throughout the body.