Authors: Miki Kanemaki, Hisae O. Shimizu, Masataka Kitama, Masaji Yamashita, Hiroko Miura, and Koichi Shimizu
Source: FERMAT, Volume 21, Communications 16, May-Jun., 2017
Abstract: Among the various biological effects of extremely low frequency (ELF) electric fields, increased peripheral blood flow occurs when a human body is exposed to an electric field. To elucidate this phenomenon, we investigated changes of red blood cell (RBC) aggregation. Fifteen volunteer participants stopped taking food at least 10 hr including sleeping period before the experiment. Blood was sampled according to a predetermined schedule, and put on a slide glass for microscopic observation. Then microscopic images of RBCs were analyzed using image-processing software. The RBCs were classified into several groups: normal, aggregated, megacytic, microcytic, and degenerated RBCs. For this study, we observed the ratios of normal and aggregated RBCs as a parameter related to the blood flow change. Each participant was exposed to the electric field using a therapeutic electric field exposure instrument (Healthtron HES-30;Hakuju Institute for Health Science Co., Ltd.) that applied high voltage (30 kV) beneath the participant’s soles of the feet. The participant’s body was electrically floated from the ground with the insulating chair. A high electric field (20–250 kV/m) was generated between the participant body and the grounded environment.
Each participant kept sitting calmly on a comfortable chair of the field exposure instrument for 5 min before the experiment started. Then blood was sampled, and the 30-min-long exposure/sham-exposure period started. At the end of the period, blood was sampled. The participant remained seated calmly on the chair for one hour. During this post-exposure period, blood was sampled every 15 min. Blood aggregation is expected to decrease with sufficient water intake by the participant. Therefore, the combined experiment of sham exposure was conducted with water intake. With our measurement system, the RBC aggregation was stable in the sham-exposure period, but it decreased with water intake. Results of this experiment confirmed the stability and sensitivity of our measurements. Then, the participant was exposed to the field and the blood samples were analyzed. Comparison between the results of sham-exposure and exposure cases revealed that blood aggregation increased about 20% because of field exposure.
To elucidate the mechanism underlying this phenomenon, we conducted another experiment of in vitro exposure of the electric field. The electric field was applied to the blood sample itself on the slide glass under a microscope. The field strength was controlled so that the induced current density in vitro was the same level as that in vivo. Consequently, the ratio of the aggregated RBCs tended to increase with in vitro exposure. Results suggest that the aggregation increase in the field exposure is attributable not only to the physiological change in the participant body but also to the physical change of RBCs or their environment. The validity of this results and the relation between blood aggregation and blood flow must be investigated further.
Index Terms: ELF electric field, Blood flow, Red blood cells (RBC’s), Aggregation, Human exposure, Biological effects
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Biological effect of ELF electric field in blood aggregation