Multichannel Recording Apparatus for Physiological Studies

Apparatus used in a study of the pathway of the excitation of the heart is described. The multipolar electrode consists of fifteen fine (50-μ) tungsten wires staggered at 1.0 or ½-mm intervals along a central shaft. Details of its construction are included. The electrode is used in conjunction with a sixteen-channel oscilloscope which permits recording from all terminals simultaneously. One channel is used for a time reference potential and one for a conventional electrocardiographic lead. A continuously variable circuit triggers the sweep. The delay is triggered by one heartbeat so that the depolarization of the heart during the next beat appears on the oscilloscope. Time signals are fed into all channels from a single oscillator. Circuit and schematic diagrams and experimental results are presented.