grapho-, graph-, -graph, -graphy, -grapher, -graphia
(Greek: to scratch; to write, to record, to draw, to describe; that which is written or described)
As indicated at the bottom of this page, there is a significantly large number of graphic word-entry groups in this unit. Such an extensive listing is provided to show how important the grapho- element is to the English language.
2. The process of recording the electric activity of the brain by electrodes placed directly on the cerebral cortex, providing a much higher voltage, greater accuracy, and more exact localization than electroencephalography.
2. An apparatus for receiving and recording the electric potential produced by the brain cells.
It consists of a vacuum tube amplifier that magnifies the electrical currents received through electrodes placed on the scalp and electromagnetically records the patterns on a graphic chart.3. An appliance that is used to amplify and to record the electrical activity of the brain, either through the intact skull and scalp, or directly from the exposed cerebral cortex (electrocorticography).
It is made up of a number of channels, each of which consists of an amplifying and recording instrument that records the electrical events beneath and between a pair of recording electrodes.
2. Pertaining to an instrument that records the electric activity of the brain.
The technologist may supervise electroencephalographic technicians, who are generally responsible for the operation and maintenance of the equipment.
2. A method of graphically recording the electric activities of the brain, particularly the cerebral cortex, with electrodes attached to the scalp.
This process is used in the diagnosis of epilepsy, trauma, tumors, and degenerations of the brain; as well as, in the study of the effects of drugs on the central nervous system and certain psychological and physiological functions.
Electrodes are placed on the scalp in various locations and the difference between the electric potential of two sites is recorded. The difference between one pair or among many pairs at a time can be determined.
The use of this diagnostic technique has proven to be very helpful in studying epilepsy and convulsive disorders and in localizing lesions in the cerebrum.
During the procedure, the patient must remain quiet, with eyes closed, and not talk or move.
In certain cases prescribed activities; especially, hyperventilation, may be requested by the technician.
The test is used to diagnose seizure disorders, brainstem disorders, focal lesions, and impaired consciousness.
During neurosurgery, the electrodes can be applied directly to the surface of the brain (intracranial electroencephalography) or placed within the brain tissue (depth electroencephalography) in order to detect any lesions or tumors that might exist.
2. A graphic recording of the change in electrical potential associated with gastric secretion and movement.
2. The process of recording and analyzing the electrical activity of the stomach.
2. An apparatus used to transmit pictures by electrical means; for example, by fax.
3. A graphic representation created by the movement of an electric current on sensitized paper or an electrically controlled writing instrument used in telecommunications.
2. The branch of electrostatography in which electrostatic images are formed on an insulating medium without the aid of eledgromagnetic radiation.
It includes xeroprinting, where the charged image is permanent, as required for repetitive printing and electrographic recording, in which the charged image is formed by electric procedures.3. Any technique involving the recording of electrical potentials in resting bodily tissues or organs, and of changes in these potentials during physiological or pathological activity.