International Encyclopedia of Rehabilitation

Current

Here are different types of electric current used in rehabilitation:

conduction current : Current due to movement of electrons from atom to atom. Type of current along metal conductors.

cutting current : Electric current used for surgical cutting.

diadynamic current : Sinusoidal current of low frequency (commonly between 50 and 1,000 Hz), with continuous modulation, which, depending upon the variations in frequency, intensity, and duration, has various physiologic effects. Developed in the 1940s by the French physician Pierre M. Bernard; little used in the USA.

diathermy current : High-frequency current that alternates so rapidly that it usually neither stimulates motor nerves nor causes burns.

direct current : Unidirectional current. Electric current that does not change polarity.

faradic current : An alternating, asymmetric current that stimulates muscles through its nerve. It is in effect, however, a direct current abruptly interrupted about 80 to 100 times per second. It is therefore one kind of tetanizing current. Originally it was produced by a faradic coil. This has been replaced by a thermionic grid-glow tube. Developed by Michael Faraday.

galvanic current : Direct current of steady flow. Term mostly used in medicine. Same as constant or continuous current. Named after Luigi Galvani.

high-frequency current : Alternating current of frequencies above 100,000 Hz, i.e., above frequencies resulting in muscular contraction. The frequencies used in diathermy are over 10,000,000 Hz and are also referred to as ultrahigh frequencies.

induced current : Current generated by induction, i.e., by the presence of another electric current nearby.

interference current : Current resulting from the intersection of two independent circuits in one apparatus. One produces a sinusoidal current of a constant frequency of about 3,000 or 4,000 Hz; the other generates a current of a slightly different and variable frequency, e.g., between 2,900 and 3,100 Hz or between 3,00 and 4,100 Hz, respectively. Developed in 1951 by the Austrian physicist Hans Nemec.

low-frequency current : Current of a frequency between 5 and 3,000 Hz, usually between 50 and 100 Hz, i.e., current capable of stimulating muscle and nerve. It is of low voltage. Also called tetanizing current.

low-voltage current : Term embracing constant, faradic, and sinusoidal currents. Also called low-frequency currents, though the constant current has, of course, no frequency.

modulated current : Current whose intensity is cyclically reduced to zero. An example of modulated current is surging current.

Oudin current : A high-frequency current of particularly high voltage, obtained by a special coil of wire, called Oudin resonator.

progressive current : Electric current that increases relatively slowly before reaching its maximum intensity.

pulsating current : Electric current that increases and decreases in intensity in a regular fashion.

sinusoidal current : A type of alternating current increasing and decreasing in intensity with symmetric variation.

surgical current : Electric current used for surgical purposes, either cutting or fulguration.

surging current : Modulated current (AC or DC), whose peak intensity gradually increases and decreases at a rate (called modulation rate) of from one second to once every ten seconds.

Tesla current : A high-frequency current, comparable to d'Arsonval current but of higher voltage, adjustable by an induction coil. Proposed by Nikola Tesla (1856-1943), Serbian physicist in New York.

tetanizing current : Electric current contracting a muscle to the point of tetanus. This is usually a current with a frequency between 50 and 200 Hz for normal muscles and between 5 and 10 Hz for denervated muscles.

Source

Eisenberg MG. 1995. Dictionary of Rehabilitation. New York: Springer Publishing Company. 375 p. Used with permission.

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