Technique for electrocardiographic monitoring of working divers

An improved technique to record high-equality electrocardiographic (ECG) signals on the surface, from immersed humans during rest and exercise, in both normothermic and hypothermic exposures, has been devised. Recorded tracings were adequate for research purposes. Waveform signals obtained allow accurate continuous monitoring as well. The best recordings resulted from proper selection of electrode placement sites, careful preparation of the skin, and diligent protection of the skin-electrode interface. The resulting signals recorded from male divers working in 3.05 m (10 ft) of water contained very little artifact or shift in baseline of the ECG tracing. Post-dive examination of the placement sites showed neither separation of ECG electrodes from the skin nor intrusion of water between the electrode and skin surface. The relationship of the new ECG recording technique to a previously described system for acquiring physiologic data is described.