A method of picking up cardiac potentials from moving human subjects for radiotelemetry.

Abstract

A comparison was made of various methods of transmitting cardiac potentials by radiotelemetry; the frequency of the heartbeat was recorded by means of the radiopulsophone, utilizing the R wave of the electrocardiogram. From the data obtained, “suction” electrodes were developed, and the paste normally employed was replaced with a 10% sodium chloride solution. The area of electrode in contact with the skin was 2.85 cm2. The procedure was as follows: complete treatment of the skin was applied using Vodolazskii's method: the upper epidermis was removed carefully by means of a cream containing finely ground pumice and the skin was then degreased with ether and alcohol. The electrodes were fixed with the, adhesive cleol, and suction. In this way, stable contact and a low value of contact, resistance was obtained, and the result was a reduction of interference originating from movement of the electrodes, and of electrical interference due to the high value of the contact resistance. When measured with a 20 cycle alternating current, the inter-electrode resistance had the low value of 500–1,500 ohm, a value which is actually lower than that obtained with subcutaneous needle electrodes. The method described will be of great use in work with biological transistor amplifiers.