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Biomedical subjects

R Waibel

Publications and source records attributed to R Waibel.

6 recordsLinked to original sources
PubMed1979

[High voltage power station to study the influence of the DC-field with superimposed AC-field on humans (author's transl)].

Due to the great progress in electrical engineering man is exposed to electric fields in a high degree. However, the effect of the electric field has not been definitely cleared up till now. The following parameters are of decisive importance: Field intensity- Frequency-Shape of curve-Boundary conditions. As scientific investigations can only be reproduced and accepted when the experimental conditions are clearly defined, a station meeting these requirements has been developed. It consists of Testing room: Electric screen damping higher than 80 dB-Magnetic screen damping higher than 45 dB-large, cased ceiling electrode. Control room: Same as testing room, but no screening. High voltage generator: a) DC-Voltage 0-20 kV ripple & noise less than 0.01%; b) Alternating voltage 0-300 Vss frequency 5 Hz-50 kHz; c) combination of a) and b).

Clinical Trials as Topic↗
PubMed1979

[The influence of electric 50 Hz fields on humans (author's transl)].

The investigations concerning the influence of supply-frequent electric fields on man have been carried out on 12 subjects in 24 single trials. A field intensity as it occurs in the height of the subjects' head under a 380 kV high voltage transmission line was used. Some physiological parameters like ECG, EEG, blood pressure, blood gas and reaction time have been recorded and analyzed. The parameters were both analogously recorded and digitally stored as indicated in Fig. 2. Some of the investigations were carried out under mental load of the subjects and showed that the changes in the heartrate due to this load cover the switch-off effect of the heartrate. For the other parameters like EEG, reaction time, blood gas and blood pressure no influence of the investigated field intensity on man could be found.

Acoustic Stimulation↗
PubMed1976

[Influence of line frequency electric fields on the heart rate of rats (author's transl)].

At present, the few published research results concerning the effect of 50 HZ fields on biological measurements, for instance on circulatory parameters, show only slight correlation. In order to find objective criteria for the infleunce of a field on heart frequency physically defineable observation conditions must first be created. In the interpretation of the results, it had to be taken into consideration that the measurements were taken immediately after application of the field in both brief and extended exposure. The effect of narcosis during derivation of cardiac activity was also a factor to be considered in this context. Keeping these facts in mind, rats were exposed for up to 50 days to a 50 Hz field with a field-strength of 50 V/m resp. 5300 V/m. Under both field-strength ranges, the heart frequency sank significantly. The intensity and the temporal development of the influence were dependent on the field-strength and the length of application. The comparatively strong frequency drop after 15 min treatment time in the 5300 V/m field points to a stress effect, whose persisting influence determines the development of the biological reaction over a longer period of time. The stronger field is comparable to the value found in the middle of the potential field of a 380 kV high-tension line. For this reason, the experimental results are interesting from the point of view of industrial hygiene as well.

Animals↗