W. B. Kouwenhoven

A-C shocks of varying parameters affecting the heart

It is well known that both the human and the dogs heart may be thrown into ventricular fibrillation by 60-cycle a-c shocks, resulting in the cessation of circulation followed by death. There are, however, little data available as to the magnitude of the current of various durations that will result in fibrillation, nor is there much information as to how the induction of fibrillation is influenced by the timing of the shock in the heart cycle. Ferris, Williams, Spence, and King1 found that the sheeps heart was most vulnerable to shocks that fell during the T phase of the electrocardiogram of the heart.

Medical Evaluation of Man Working in AC Electric Fields

This paper covers an investigation of the effects of HV 60-Hz ac fields on human beings. Experimental results of the intensity of the electric fields to which linemen are subjected when doing maintenance work on energized HV lines are presented. The protection offered by Faraday screens is discussed. The results of a series of physiological examinations that were carried out on 11 linemen, some of whom used conventional hot stick methods and others worked barehanded from an aerial bucket connected to an energized conductor, are presented. The examinations, which extended over a 42-month period, were conducted by members of the staff of The Johns Hopkins Hospital, Baltimore, Md.

Effects of electricity on the human body

With the advent of man-made electricity, still another contributing factor to the mortality rate comes up for consideration; in the utility field alone employee deaths ascribable to electricity currently average 70 to 80 per year. As a matter of general information for the engineer working with electric current, this article discusses the basic principles and data concerning electric shock and indicates some of the physiological conditions which result.

Medical Follow-Up Study of High Voltage Linemen Working in AC Electric Fields

This paper presents the final results of the effects upon the health of linemen engaged in the maintenance of energized electrical transmission over a period of nine years. An initial report1,2 was presented in 1966 at the IEEE Summer Meeting in New Orleans, and the study has been continued to 1972. The evaluation was begun in December 1962 with ten linemen, four from the Ohio Power Company and six from the Appalachian Power Company (American Electric Power System).

A High Sensitivity Power Factor Bridge

AN A-C. BRIDGE of high precision has been developed for power factor measurements in an investigation of the properties of cable compounds and papers and of the characteristics of cables that occur after impregnation. The bridge, a modified form of the Schering bridge, possesses several novel features and advantages. The detecting instrument is a moving coil a-c. galvanometer with field excitation supplied from a phase shifting transformer permitting independent ratio and phase-angle balances. A shielded transformer electrostatically isolates the galvanometer from the bridge circuits. This bridge is completely shielded and guarded.

Effect of Electric Shock

This paper describes an investigation of the effects of electric shock on the central nervous system. A total of 286 rats was employed in the investigation. These were shocked at 110, 220, 500, and 1000 volts on both alternating and continuous current circuits for varying lengths of time. In each series the duration of the shock was increased until it was found impossible to resuscitate the rats. When possible the rats were resuscitated by means of artificial respiration, and kept alive for about a week. Then they were killed by an overdose of ether and an autopsy was immediately made. The rats reacted in entirely different manner on the two types of circuit. At the lower voltages the alternating current was deadlier than the continuous, but at the high voltage the opposite was found to be the case. In many instances the rats were paralyzed by the application of the current and in the majority of these animals gross hemorrhages were found in the spinal cord at autopsy. All of the deaths that occurred as a result of the shock were caused by respiratory failure, which could usually be traced to an injury of the central nervous system. In some cases the electric current produced peculiar effects upon the rats.

Electric Shock Effects of Frequency

Supplementing earlier research progress reports1 concerning the physiological effects of electric shock, the authors here present the results of a sereies of experiments made to determine the heart reaction to currents of different frequencies.

Absolute power factor of air capacitors

STANDARD air capacitors are used with measuring equipment of high sensitivity for comparison with test capacitors in investigations such as the study of dielectric materials; therefore the absolute power factor of the standard should be known. In the investigation reported in this paper,∗ seven air capacitors of different types of construction were studied. A method of determining the absolute power factor of an air capacitor was developed, and data were obtained on the effects produced by the degree of polish of the electrode surfaces, by the width of gap between the measuring electrode and its guard ring, and by the presence of water films on the plates.

Resuscitation by countershock

The possibility of recovery of the fibrillating heart has been the subject of extensive experimental work, the results of which demonstrate conclusively that normal rhythmic functioning can be restored successfully in many cases.

Effect on Breathing of an Electric Shock Applied to the Extremities

Electric shock frequently causes the arrest of breathing. This paper reports on an experimental investigation of this phenomenon. A convulsion is a likely consequence of a high voltage shock applied to the extremities. It is suggested that this convulsion may be reponsible for breathing failure.