There are 3 types of Diagnostic Instruments. They are
1.Electrocardiogram (EKG or ECG)
2. An electroencephalogram (EEG)
3. Magneto encephalography (MEG)
1. Electrocardiogram (EKG or ECG)
* Willem Einthoven was a Dutch doctor and physiologist. He invented the first practical electrocardiogram (ECG or EKG) in 1903 and received the Nobel Prize in Medicine in 1924 for it.
* An electrocardiogram is a test that checks for problems with the electrical activity of your heart. An EKG shows the heart's electrical activity as line tracings on paper. The spikes and dips in the tracings are called waves. It gives sonographic pictures.
2. An electroencephalogram (EEG)
An electroencephalogram (EEG) records electrical impulses from the nerves in the head. "Electro" refers to the electrical impulses sent from one nerve cell to another. These impulses are the way nerves talk to each other and get information from the brain to the rest of the body. "Encephalo" refers to the head, and "gram" refers to the printed record.
EEG exams are done by putting electrodes (detectors of electricity) on the scalp and seeing what the electrical impulses look like when the patient is awake, asleep, in a room with a flashing light or sometimes when the patient is asked to breathe deeply over and over. When the EEG is done, no electricity is put in to or taken out of the patient. The electrical signals that the brain produces are simply detected and printed out on a computer screen or a piece of paper.
Hans Berger was a German neurologist, best known as the inventor of electroencephalography (EEG) (the recording of "brain waves") in 1924, coining the name, and the discoverer of the alpha wave rhythm known as "Berger's wave".
EEG is used to look at your brain activity. It can be used to diagnose or monitor the following health conditions
i. Abnormal changes in body chemistry that affects the brain
ii. Brain diseases, such as Alzheimer disease
iii. Confusion
iv. Fainting spells or periods of memory loss that cannot be explained otherwise
v. Head injuries
vi. Infections
vii. Seizures
viii. Tumors
EEG is also used to:
i. Evaluate problems with sleep (sleep disorders).
ii. Monitor the brain during brain surger.
3. Magneto encephalography (MEG)
Magneto encephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers. Arrays of SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, while the SERF (spin exchange relaxation-free) magnetometer is being investigated for future machines. Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and neurofeedback. This can be applied in a clinical setting to find locations of abnormalities as well as in an experimental setting to simply measure brain activity.
David Cohen, a faculty member at Harvard Medical School and Massachusetts General Hospital, was honored by the McGovern Institute for Brain Research for his invention of magneto encephalography (MEG), a powerful and noninvasive method for measuring human brain activity.
