The electrocardiogram (ECG or EKG) is a diagnostic tool that is routinely used to assess the electrical and muscular functions of the heart. While it is a relatively simple test to perform, the interpretation of the ECG tracing requires significant amounts of training.
In medicine, a Holter monitor (often simply "Holter" or occasionally ambulatory electrocardiography device) is a portable device for continuously monitoring various electrical activity of the cardiovascular system for at least 24 hours (often for two weeks at a time).
Spirometry is a test that can help diagnose various lung conditions, most commonly chronic obstructive pulmonary disease (COPD). Spirometry is also used to monitor the severity of some other lung conditions, and their response to treatment.
There are two basic types of endoscopy: Upper endoscopy – The esophagus, stomach, and small intestines can be viewed by a thin flexible tube inserted through the mouth. Colonoscopy – The lining of the large intestine, colon and rectum can be viewed by a flexible tube inserted through the rectum.
Uroflowmetry measures the flow of urine. It tracks how fast urine flows, how much flows out, and how long it takes. It’s a diagnostic test to assess how well the urinary tract functions. Your doctor may suggest uroflowmetry if you have trouble urinating, or have a slow stream.
An electroencephalogram (EEG) is a recording of brain activity. During the test, small sensors are attached to the scalp to pick up the electrical signals produced when brain cells send messages to each other. These signals are recorded by a machine and are looked at by a doctor later to see if they're unusual.
An electromyogram (EMG) measures the electrical activity of muscles at rest and during contraction. Nerve conduction studies measure how well and how fast the nerves can send electrical signals. Nerves control the muscles in the body with electrical signals called impulses.