It has become sufficiently clear that if in taking human electrocardiograms there is overshooting of the string, a high resistance has probably developed at the site at which the electrodes have been applied to an individual. Overshooting is, of course, undesirable because it deforms the curve. A high metallic resistance interposed in the circuit does not cause this defect. The deformity is seen either when an added resistance is introduced into the circuit or when a current passes. In the latter instance the overshooting is the greater, the greater the voltage. It has likewise become sufficiently clear, that if the resistance in the string-patient circuit is reduced below 2,000 ohms, the overshooting does not take place. It makes no difference so far as electrocardiography is concerned what is the reason of the overshooting—whether due to polarization at the electrodes or to a capacity effect in the cutaneous tissues as Pardee1
COHN AE. A NEW ELECTRODE FOR USE IN CLINICAL ELECTROCARDIOGRAPHY. Arch Intern Med (Chic). 1920;26(1):105–113. doi:10.1001/archinte.1920.00100010108008
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