What piece of equipment is used to measure O2 saturation levels of arterial blood during a surgical procedure?

The piece of equipment used to measure O2 saturation levels of arterial blood during a surgical procedure is a pulse oximeter. This device works by emitting light wavelengths that reflect off the blood and provides a non-invasive estimation of the oxygen saturation level of hemoglobin in the blood. By doing so, it gives healthcare professionals real-time data on a patient's respiratory status, which is critical during surgeries where oxygen levels need to be closely monitored.

Other equipment, such as blood pressure monitors, heart rate monitors, and electrocardiograms, serve different purposes. A blood pressure monitor measures the pressure of blood in the arteries, a heart rate monitor tracks the heart's beats per minute, and an electrocardiogram records the electrical activity of the heart. While these are all essential during surgical procedures, they do not assess oxygen saturation specifically, which is why the pulse oximeter is the correct answer for monitoring O2 saturation levels.