What device is used to measure oxygen saturation levels and pulse rates?

The device used to measure oxygen saturation levels and pulse rates is a pulse oximeter. This non-invasive tool works by using light sensors to detect the amount of oxygen in the blood by analyzing the absorption of light as it passes through the skin. It provides a quick and accurate reading of both oxygen saturation (expressed as a percentage) and the heart rate, making it an essential device in both clinical and home settings for monitoring patients' respiratory and cardiovascular health.

In contrast, a stethoscope is primarily used to listen to internal body sounds, such as the heartbeat and lung sounds, rather than measuring oxygen levels or pulse rates directly. A thermometer is designed to measure body temperature, providing information related to fever or hypothermia. The sphygmomanometer measures blood pressure and does not provide information regarding oxygen saturation or heart rate. Thus, the pulse oximeter is uniquely suited for measuring the parameters in the question.