Arterial Blood Gases. Test Overview. An arterial blood gas (ABG) test measures the acidity (pH) and the levels of oxygen and carbon dioxide in the blood from an artery. This test is used to check how well your lungs are able to move oxygen into the blood and remove carbon dioxide from the blood.
How Often the Test Is Done During Your Pregnancy. Your doctor may use the Doppler often to listen to your baby's heartbeat during routine checkups, starting at about 8 to 10 weeks. Handheld Dopplers will not work quite this early.
It's one of the most widely recognised symbols of medicine worn around the necks of most doctors, but what do they listen for through the stethoscope? The stethoscope is an instrument used by doctors and other health professionals to listen to body sounds. It is mainly designed to listen to the lungs and heart, although it is also used to listen to the bowels and blood flow in other parts of the body.