This study will help the investigators learn more about whether a partially wireless, more portable pulse oximeter that connects to a small device worn on the child's arm or leg will give the investigators a more reliable signal/reading while letting children move more easily. The investigators will compare this device with the traditional wall-connected unit. Movement of the cable or a child moving may give a false oxygen reading. The investigators will ask the child to do activities that create movement and will look at the readings when the child moves. The investigators think the partially wireless pulse oximeter will be more reliable during movement than the traditional wall-connected unit.