![video eeg video eeg](https://46rrgg4cwviq26oexe3a366g-wpengine.netdna-ssl.com/wp-content/uploads/2020/12/veeg-img5.png)
The final signal can then be displayed on an external computer screen as a visual representation of the EEG signals measured.
![video eeg video eeg](https://46rrgg4cwviq26oexe3a366g-wpengine.netdna-ssl.com/wp-content/uploads/2020/10/patients-page-round-image.png)
The acquired analog signal is then converted to a digital signal to allow processing and storage of the data using an analog-to-digital converter which is then filtered to remove any signal noise not associated with the neuronal activity. The electrical signals from these electrode transducers are then amplified using differential amplifiers to measure potential differences from one area of the scalp or brain to another. In either case, these EEG measuring techniques allow one to non-invasively measure action potentials of groups of neurons within the brain using transducers called electrodes. This test format allows at-home or extended monitoring in clinics and hospitals where the standard EEG monitoring was previously unable to be used. From these easy uses and techniques, a longer-term method of EEG monitoring was developed called long-term video-EEG monitoring which applies these same brain-wave monitoring techniques in a long-duration test format. These developments lead to the modern EEG techniques which allow for non-invasive measurements using externally placed EEG caps and were established by William Grey Walter in the 1950s. Additional developments made using animal subjects persisted through the early 1900s including the work of Vladimir Vladimirovich Pravdich-Neminsky in 1912, Napoleon Cybulski and Jelenska-Macieszyna in 1914, as well as by Hans Berger in 1924 with the first human EEG recording. In these studies, electrodes were placed directly on the surface of the brain. In 1890, his work was expanded upon by Adolf Beck as developments to the technique were enhanced through animal studies of rhythmic oscillations in the brain due to light stimuli. Like standard EEG-testing, long-term video-EEG monitoring techniques developed from techniques in 1875 by Richard Caton in Liverpool. Electroencephalograph machine (left) with computer monitor (center) for display and photic device for stimulation.