At first, pulse oximeters flew off the shelves along with toilet paper. The pulse oximeter can detect even small changes in the way lungs move oxygen to the rest of the body. Doctor Levitan recommends using pulse oximeters if patients are high-risk. The pulse oximeters are available over the counter at most drug stores ranging in cost from 40 to about 70 dollars. The device is most often used on the index finger, looking for a normal oxygen range of 95-100.