Department of Electrical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Neuroimage. 2011 Jan;54 Suppl 1:S30-6. doi: 10.1016/j.neuroimage.2010.05.042. Epub 2010 Jun 12.
In this paper, we show that bone piezoelectricity-a phenomenon in which bone polarizes electrically in response to an applied mechanical stress and produces a short-range electric field-may be a source of intense blast-induced electric fields in the brain, with magnitudes and timescales comparable to fields with known neurological effects. We compute the induced charge density in the skull from stress data on the skull from a finite-element full-head model simulation of a typical IED-scale blast wave incident on an unhelmeted human head as well as a human head protected by a kevlar helmet, and estimate the resulting electric fields in the brain in both cases to be on the order of 10 V/m in millisecond pulses. These fields are more than 10 times stronger than the IEEE safety guidelines for controlled environments (IEEE Standards Coordinating Committee 28, 2002) and comparable in strength and timescale to fields from repetitive Transcranial Magnetic Stimulation (rTMS) that are designed to induce neurological effects (Wagner et al., 2006a). They can be easily measured by RF antennas, and may provide the means to design a diagnostic tool that records a quantitative measure of the head's exposure to blast insult.
在本文中，我们表明骨压电性——骨头在受到机械应力作用时会产生电偶极矩并产生短程电场的现象——可能是大脑中强烈爆炸感应电场的来源，其幅度和时间尺度可与具有已知神经效应的电场相媲美。我们从一个典型的简易爆炸装置规模爆炸波对未戴头盔的人头和戴凯夫拉头盔的人头的全头部有限元模型模拟的颅骨上的应力数据中计算颅骨中的感应电荷密度，并估计这两种情况下大脑中的感应电场都在 10 V/m 量级的毫秒脉冲范围内。这些场强比 IEEE 受控环境安全指南（IEEE Standards Coordinating Committee 28, 2002）强 10 多倍，与旨在诱导神经效应的重复经颅磁刺激（rTMS）的场强和时间尺度相当（Wagner 等人，2006a）。它们可以很容易地通过射频天线测量，并且可能提供一种设计工具的手段，该工具记录头部暴露于爆炸冲击的定量测量。
