Magnetohydrodynamic Approach to Effective Blood-Flow Control Utilizing ELF fields
Magnetohydrodynamic Approach to Effective Blood-Flow Control Utilizing ELF fields
复制标题
利用 ELF 场有效控制血流的磁流体动力学方法
DOI：
10.1109/intmag.2018.8508699
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Mikio Ohuchi
中科院分区：
文献类型：
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作者：
Hidenori Nakagawa;Mikio Ohuchi
为了描述磁流体动力学（MHD）研究的广泛潜在机会，我们研究了极低频（ELF）磁场的MHD效应，该磁场由一个从现有的交变磁疗装置（AMTA）转移的原型产生，采用功能近红外光谱（fNIRS）分析。实验5名年龄在33岁至68岁之间的健康男性受试者（30岁和40岁的受试者各2名，60岁的受试者1名）参加了该实验。对于受试者的ELF刺激，我们使用配备有两个额外线圈的原型，用于扭转商业AMTA（NIKKEN，Biobeam 21）的ELF场。AMTA的磁通密度分布如图1所示。最大密度显示为60 mT，在每个中心的内部铁芯。在0.34 A的恒定电流下，我们能够在线圈表面上获得1060 mT。然后，将所有线圈的场频率固定在50 Hz，并且根据人体的一部分的轴，使来自附加线圈的正弦波形信号在相位上同步。所有的fNIRS（Hitach HOT 121 B）测量都是在温度和湿度为50%的安静房间中坐在椅子上进行的。讨论我们的实验结果表明，适当的扭曲ELF场诱导的原型机器能够控制自主神经系统，这取决于场强。因此，我们估计ELF刺激引起的血流加速的机制是由于由感应涡流产生的温度升高，以及电流的焦耳-热梯度。因此，在人体生物活性的过程中，血液流动可能通过自主神经系统加速[1-4]，以减少诱导的发热和/或热梯度。另一方面，在两个安装位置（图2A和2B）之间，动脉/静脉血流的行为没有显著差异。很可能动脉血流（图2A）不能产生激活自主神经系统所需的涡流，尽管作为脉动流的血流可能在流体中引起电磁感应现象。我们坚信，虚拟磁疗法的MHD效应是由血液中的适度扫掠湍流引起的。
To describe the broad potential opportunities in magnetohydrodynamic (MHD) studies for magnetic therapies, we examined the MHD effects of extremely low frequency (ELF) magnetic fields produced by a prototype diverted from an existing alternating magnetic therapy apparatus (AMTA), employing functional near-infrared spectroscopic (fNIRS) analyses. Experimental Five healthy male subjects ranging in age from 33 to 68 (two subjects each in their 30 s and 40 s, and one subject in his 60 s) took part in this experiment. For ELF stimulations to the subjects, we used a prototype equipped with two additional coils for twisting the ELF field of a commercial AMTA (NIKKEN, Biobeam 21). The flux-densitydistribution from the AMTA is shown in Fig. 1. The maximum density was revealed as 60 mT at each center of the internal iron core. We were able to obtain theof 60 mT on the coil surface, under a constant current of 0.34 A. Then the field frequencies of all the coils were fixed at 50 Hz, and the sinusoidal waveform signals from the additional coils were synchronized in phase in accordance with the axis of a part of the human body. All measurements on fNIRS (Hitach HOT121B) were carried out while the subjects were sitting on a chair in a quiet room at a temperature ofand humidity of 50%. Discussion Our experimental results showed the fact that the proper twisted ELF fields induced from the prototyped machine were able to control the autonomic nervous system, depending on the field strength. We therefore estimated that the mechanism of blood-flow accelerations induced by ELF stimulations is due to a little temperature increase generated by an induced eddy current, and the following joule-heat gradient of the current. Consequently, the blood flow is probably accelerated in the process of human bioactivity via the autonomic nervous system [1–4], in order to reduce the induced fever and/or the heat gradient. On the other hand, there were no significant differences across the two mounting positions (Fig. 2A and 2B) in the behaviors of arterial/venous blood flows. It is quite probable that the arterial blood flows (Fig. 2A) could not generate an eddy current necessary for activations of the autonomic nervous system, although the flows grasping as a pulsating flow might induce an electromagnetic induction phenomenon in a fluid. We firmly believe that MHD effects for a virtual magnetic therapy are induced by moderately swept turbulence in the blood.