Basic of EEG Machine

Electroencephalography continues to be an essential diagnostic test in clinical practice and its use has evolved over nearly 90 years since its invention ( by Hans Berger in 1929). Approaching EEG interpretation for the first time requires some understanding of EEG’s basis, recording technology, and general capabilities and limitations. With understanding of these facets, the EEG activity is more clearly interpreted and the diagnostic questions can be more readily addressed. Therefore, we need to know about electricity and electronics as they relate to EEG. The basic systems of an EEG machine include data collection, storage, and display. The components of these systems include electrodes, connecting wires, amplifiers, a computer control module, and a display device. The EEG amplifiers convert the weak signals from the brain into a more discernable signal for the output device. They are differential amplifiers that are useful when measuring relatively low-level signals. A variety of output printers and monitors are available for EEG machines. Since the data collected is analog, it must be converted to a digital signal so electronic output devices can be used. Therefore, the primary circuitry of the EEG typically has a built-in analog to digital converter section.