Analysis of Red Blood Cell Movement in Whole Blood Exposed to DC and ELF Electric Fields

Abstract

To evaluate hematological effects of direct current (DC) and alternating current (AC) extremely low frequency (ELF) electric field exposure, this study investigated red blood cell (RBC) movement in whole blood. Video images of RBCs were recorded under a microscope using specially designed electrode systems. Video analysis software was then used to measure the RBC velocity. The noise level and measurement system stability were confirmed based on results of a no‐field exposure experiment. Using the electrode system to produce a non‐homogeneous electric field, different movements were found to occur in DC and AC field exposure. The RBCs moved in the directions of the electric field and the gradient of field distribution, respectively, in the DC and AC fields. Dependences of the RBC velocity on the field strength were, respectively, linear and quadratic in the DC and AC fields. These results suggest that electrophoretic and dielectrophoretic movements were, respectively, dominant in the DC and AC fields. The magnitude of the electric field necessary to cause these effects was found to be 103–105 times greater than the internationally publicized guideline for human safety. © 2022 Bioelectromagnetics Society.

Quantitative analyses of RBC movement in whole blood exposed to DC and ELF electric field

“…This experiment was conducted at laboratory temperatures of 22–26°C. The sample temperature stability was confirmed as reported in an earlier report (Kanemaki et al, 2022).…”

“…(3) In the previously reported experiments (Kanemaki et al, 2022), the blood sample was confined in a thin layer with 0.020 mm vertical thickness, but it was spread over an approximately 100 mm 2 horizontal area. To simulate the blood capillary condition better, we made a small channel of approx.…”

“…Studying the biological effects of electric fields requires clarification of the threshold of the electric field at which effects begin to occur. An earlier report (Kanemaki et al, 2022) described that the RBC velocity changes, and that changes occurred above 0.40 and 2.0 kV/m, respectively, for DC and AC electric fields. Nevertheless, the threshold values remain unknown.…”

“…However, almost all of these phenomena have been observed in diluted blood samples. Therefore, we have investigated blood cell movement when whole blood is exposed to an electric field (Kanemaki et al, 2022), bearing in mind electric field exposure effects on blood inside the body.…”

“…However, in the earlier study, the exposure field was uniform in the DC field, or the field gradient was uniform in the AC field. Furthermore, the electric field was exposed by application of a voltage with the electrodes in direct contact with the blood (Kanemaki et al, 2022). Therefore, for this study, we quantitatively analyzed the effects of electric field exposure under more realistic conditions, keeping in mind the exposure of a human body to electric fields in industrial and medical applications.…”