EEG Machines: What Is Their History and How Do They Work?
The EEG machine is a crucial tool in the diagnosis of many diseases. Experts predict ongoing increases in EEG use globally. The U.S. alone is responsible for 41 percent of the growth.
Are you an EEG technologist or involved with EEG tests in other ways? Do you know when and how the idea of EEG studies started? Keep reading this guide to the EEG machine to learn interesting facts.
The EEG Machine
The EEG machine history begins with a scientist named Luigi Galvani in 1780. Galvani found that a dead frog’s legs muscles twitched when touched by electricity.
He and his contemporaries agreed that nerves carry electrical fluid to muscles. Thus, electrical activity is essential for nerve conduction and muscle contraction.
Using this information, Alessandro Volta created the battery. In 1809, Luigi Rolando first stimulated an animal’s cortical cortex using galvanic current. He found that this highlighted the function of different parts of the brain.
Later, scientists discovered that the brain’s electrical stimulation causes contralateral motor responses. At the time, experts didn’t know if this intrinsic electrical brain current could be recorded.
On July 6, 1924, Hans Berger generated the first electrocorticogram. He made this recording during a 17-year-old boy’s neurosurgical operation. His report described the graphical recording as alpha and beta waves.
Soon after, a group of American EEG pioneers identified further information. H. and P. Davies, F. and E. Gibbs, Lenox, and Jasper described spikes and waves.
Berger had previously interpreted these variations as only artifacts. This became a significant milestone for advancing neuroscience and EEGs.
Luigi Galvani’s experiment demonstrated that a frog’s legs can twitch when electricity passes through the muscle.
How an EEG Machine Works
Modern EEG machines use small electrodes and wires attached to the patient’s head. These electrodes detect the brain’s electrical signals.
Then the machine amplifies the signal. It records a wave pattern on paper or computer screens.
Today, patients have EEGs performed in different settings based on their diagnostic needs. For example, standard EEGs may take place in an office setting and last about one hour.
Some patients wear a portable EEG recorder for several days or weeks. This ambulatory EEG provides information to assist with diagnosis and medication dosing.
Physicians may order inpatient testing for patients with sleep disorders or frequent seizures. They’re monitored using both video and EEG machines.
The physician can correlate physical responses to changes in brain activity. EEG data interpretation requires an expertly trained neurologist.
Previously, this meant spending a significant amount of time searching for abnormalities. New technology uses automated algorithms and machine learning to highlight areas of concern. Then the physician can more efficiently focus on these identified wave patterns.
The Rendr Platform by Lifelines Neuro generates more efficient and better diagnostic results. Software developers worked with neurologists to fine-tune and field-test the software. Its user-friendly graphic interface and tools record, track, and review EEG data.
The EEG Procedure
EEG technicians perform the tests on patients. They apply special abrasive skin prep to reduce skin-electrode impedance. Next, a conductive paste is applied to adhere the electrodes and further lower impedance.
Electrode cup choices include disposable, reusable, silver/silver chloride, or gold. The key is for the electrode to function optimally throughout the test.
The electrode wires come in 48- and 60-inch lengths. If the patient is undergoing a long-term test, the longer wires are often preferable. It’s key to avoid mixing the wire lengths in order to facilitate common-mode rejection.
When securing the electrode to the skin, you may use Hypafix or Collodion. Bundle the electrode wires together with Coban to reduce artifact on the recording. If needed, use Tubular Elastic Retention Netting or Kerlix roll as a head wrap.
Conditions an EEG Machine Diagnoses
EEGs are now used as a tool in diagnosing many different neurological conditions. One of its most common uses is to look for seizure activity and epilepsy. It allows the physician to determine the type of seizure and where it originates from.
Today, EEGs are also used to evaluate sleep-related disorders. Often this involves the use of both the EEG machine and a video camera. This helps correlate brain and physical activity.
EEGs are key tools in the diagnosis of psychogenic nonepileptic seizures (PNES). A 2021 study found that 23.8/100,000 patients with intractable seizures had PNES. Including video and EEG increased the diagnostic certainty.
Participants aged 15 to 19 years had the highest prevalence of PNES. The study reported a rate of 59.5/100,000.
Neurologists use EEG to diagnose brain tumors, strokes, head injuries, and dizziness. These conditions change the brain’s electrical wave patterns. EEGs may also serve as part of the diagnostic workup for headaches and dementia.
In patients who are thought to have brain death, the EEG may be part of the protocol. The purpose is to establish electrocerebral inactivity of the brain and brain stem. Other diagnoses also include apnea and lack of response to painful stimuli.
Would Advanced EEG Diagnostic Systems Improve Your Practice?
This article provided a history of how the EEG machine came into being. Lifelines Neuro develops medical technology and delivers neurodiagnostic expertise.
Our products include portable video EEG monitoring devices for diagnosing neurologic disorders. We offer in-clinic, in-home, take-home, or hospital-based equipment. This puts EEG capabilities wherever they’re needed.
Lifelines Neuro Trackit brainwave monitoring systems and amplifiers provide robust results. Our Rendr Platform EEG software provides a powerful cloud-computing solution. You can access this 24/7/365 on any device, which allows you to scale as your practice grows.
Request a free consultation today to learn more about our products and services.