File:Principles of electro-medicine, electrosurgery and radiology - a practical treatise for students and practitioners. With chapters on mechanical vibration and blood pressure technique (1917) (14574157910).jpg

Identifier: principlesofelec00mati (find matches)
Title: Principles of electro-medicine, electrosurgery and radiology : a practical treatise for students and practitioners. With chapters on mechanical vibration and blood pressure technique
Year: 1917 (1910s)
Authors: Matijaca, Anthony
Subjects: Vibration Electrotherapeutics X-rays Blood pressure Electric Stimulation Therapy X-Ray Therapy Electrosurgery
Publisher: Butler, New Jersey Tangerine, Fl. New York City : Published by Benedict Lust
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

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r from 10 to 30 minutes, and are given daily at first innearly all cases, gradually decreasing as the patient improves. Direct Application of DArsonval Current DiathermyDArsonval current directly applied by means of two metallic elec-trodes in passing over a small cross section through the internal tissueof the body, generates a purely mechanical heat, by overcoming the re-sistance of the tissue, in the same way as electricity heats the resistancewire in passing through it. The higher the frequency and stronger thecurrent, the greater the heat production. Electro-Medicine, Electro-Surgery and Radiology 53 This method of heat production recently elaborated by Dr. FranzNagelschmidt, of Berlin, which will probably in the near future take theleading place in electro-therapeutics is called Diathermy, or Thermo-penetration. Generation of Diathermic Currents For the reason that the heat effect of the DArsonval current chieflydepends on the frequency of the oscillations, most of the apparatus
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Fig. 18—Patient undergoing auto-con-duction treatment. generating this current for diathermic applications, have special con-densers (mica-tin-foil, or Leyden jars) and a multiple spark-gap (whichcauses a discharge of a number of short fine sparks), so as to increasethe oscillations to a very high frequency. Therefore, the DArsonvalcurrent for diathermy differs from the ordinaiy DArsonval, in being ofa much higher frequency (100,000 to many millions of oscillations persecond), a higher amperage (up to 3000 to 4000 milliamperes) and alower voltage (250 to 1000 volts). 54 Anthony Matijaca Localization of the current Since the current passes directly from one electrode to the other, andsince a small active electrode causes greater concentration of heat, withless current in a relatively shorter period than a large one, the heat canbe localized and concentrated at will, by the position and the size of theelectrodes, e. g., two large electrodes of the same size applied on theopposite side

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