Galvano-Faradization

GALVANO-FARADIZATION, the simultaneous action on the same area of a patient's body of a galvanic and a faradic current through a single pair of electrodes. The origin of this method dates back to the time when the spheres of therapeutic action of galvanic and faradic currents had not yet been delineated. The desire to simultaneously utilize the characteristic features of both currents was based on physiological data. The influence of the galvanic current on nerve excitability, studied by Pflüger, is expressed in the phenomena of electrotonus, i.e., in the change in nerve excitability at both poles during the passage of a current (see Electrodiagnosis). Although the phenomena of electrotonus could not be fully confirmed in humans, the fact that the passage of a direct current influences the electrical excitability of muscles can be considered established. Preliminary stable galvano-rization of some group of muscles makes it possible to obtain their motor reaction when using weaker currents (Heidenhain, Babinski, Delherm, Jaroschewsky). The direct current reduces the phenomena of muscle fatigue caused by the faradic current. These data justify the simultaneous use of galvanic and faradic currents in certain cases. For the simultaneous passage of both currents through a single pair of conductors, de Watteville proposed a special switch making it possible to direct either the galvanic or the faradic current or both currents together to the electrodes. According to the attached diagram (see figure), in de Watteville's switch one pole of the direct current source is connected to one of the poles of the alternating, faradic current source (with a series connection being preferred); from the terminals of the remaining two free poles (one of the direct, the other of the faradic currents) wires go to the electrodes, which are applied to the patient's body. Hydrophilic interlayers are placed under these electrodes. The dosage of the direct current is performed using a rheostat or potentiometer and is measured by a milliammeter; the dosage of the faradic current is performed by sliding the secondary coil. Galvano-faradization can also be carried out without de Watteville's combiner. For this purpose, not two, but four electrodes are used; the galvanic current is introduced separately through one pair of electrodes, and contractions of the corresponding muscles are induced by the faradic current on the same area of the body using the other pair of electrodes. With this modification (Babinski), it is possible to obtain muscle contraction even with their reduced faradic excitability. Galvano-faradization is used to induce energetic, strong contractions of deeply lying muscles. Galvano-faradization may prove useful in intestinal atonia, prolonged constipation, weakness of the urinary bladder, and muscular atrophies with a significant decrease in electrical excitability. In the presence of a weak direct current source and a weak induction coil, when neither current separately gives a sufficient motor reaction, their combined use in the form of galvano-faradization can produce the desired effect.