Changes

A pulse oximeters measures the level of oxygen saturation of the blood by shining a light through the skin, usually at the finger. Standalone pulse oximeters are available from Amazon for less than $100. Two popular oximeters are an unbranded model for $55 [http://www.amazon.com/Finger-Pulse-Oximeter-SM-110-Carry/dp/B000GEBU9K Finger Pulse Oximeter SM-110] and the $100 [http://www.amazon.com/gp/product/B002CAPUWY Nonin GO2].