Pulse oximeters are medical devices used to measure a patient's blood oxygen saturation (SpO2) and pulse rate. They are non-invasive and typically clip onto a patient’s finger, toe, or earlobe to assess oxygen delivery to the body's extremities.

Key components include:

1. Sensor/Probe: Clips onto the patient's extremity to detect oxygen levels.
2. Display Screen: Shows real-time oxygen saturation and pulse rate.
3. Alarm System: Alerts if oxygen levels or pulse rate fall outside the normal range.
4. Power Source: Typically battery-powered for portability.

Pulse oximeters are crucial for monitoring patients with respiratory or cardiac issues, enabling timely medical interventions.