2016 年 28 巻 3 号 p. 97-106
In this paper, we developed a magnetic field generating coil for finding out an effective magnetic field for supercooled freezing of biological tissues under the magnetic field. The range of the frequency and the magnetic flux density of the inducing magnetic field was expanded by reducing the resistance compared with the previous coil. The upper range of the frequency increased from 2 kHz to 10 kHz and that of the magnetic flux density increased from 0.3 mT to 2.0 mT. We evaluated the magnetic field dependency of the degree of supercooling of the porcine ovarian tissues using the developed coil. In supercooled freezing, it is reported that the growth of the ice crystals, which is a cause of cell destruction, was suppressed with the increase of the degree of supercooling. This result indicates that increasing the degree of supercooling may enable to prevent cell destruction. Therefore we evaluated the effect of the magnetic field by measuring the degree of supercooling. As a result of the measurement, the averages of the degree of supercooling at 10 kHz frequency of 2.0 mT magnetic field increased the most from 9.1 ± 1.7 °C for without magnetic field to 10.5 ± 1.7 °C.