Kiourti Asimina, Nikita Konstantina S
School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece.
Bioelectromagnetics. 2013 Apr;34(3):167-79. doi: 10.1002/bem.21753. Epub 2012 Sep 4.
We numerically assess the effects of head properties (anatomy and dielectric parameters) on the performance of a scalp-implantable antenna for telemetry in the Medical Implant Communications Service band (402.0-405.0 MHz). Safety issues and performance (resonance, radiation) are analyzed for an experimentally validated implantable antenna (volume of 203.6 mm(3) ), considering five head models (3- and 5-layer spherical, 6-, 10-, and 13-tissue anatomical) and seven scenarios (variations ± 20% in the reference permittivity and conductivity values). Simulations are carried out at 403.5 MHz using the finite-difference time-domain method. Anatomy of the head model around the implantation site is found to mainly affect antenna performance, whereas overall tissue anatomy and dielectric parameters are less significant. Compared to the reference dielectric parameter scenario within the 3-layer spherical head, maximum variations of -19.9%, +3.7%, -55.1%, and -39.2% are computed in the maximum allowable net input power imposed by the IEEE Std C95.1-1999 and Std C95.1-2005 safety guidelines, return loss, and maximum far-field gain, respectively. Compliance with the recent IEEE Std C95.1-2005 is found to be almost insensitive to head properties, in contrast with IEEE Std C95.1-1999. Taking tissue property uncertainties into account is highlighted as crucial for implantable antenna design and performance assessment. Bioelectromagnetics 34:167-179, 2013. © 2012 Wiley Periodicals, Inc.
我们通过数值评估头部特性（解剖结构和介电参数）对用于医疗植入通信服务频段（402.0 - 405.0 MHz）遥测的头皮可植入天线性能的影响。针对一个经过实验验证的可植入天线（体积为203.6 mm³），分析其安全性问题和性能（共振、辐射），考虑了五种头部模型（3层和5层球形、6、10和13组织解剖模型）以及七种场景（参考介电常数和电导率值变化±20%）。使用时域有限差分法在403.5 MHz进行模拟。发现植入部位周围头部模型的解剖结构主要影响天线性能，而整体组织解剖结构和介电参数的影响较小。与3层球形头部内的参考介电参数场景相比，根据IEEE Std C95.1 - 1999和Std C95.1 - 2005安全指南计算得出，在最大允许净输入功率、回波损耗和最大远场增益方面，最大变化分别为 - 19.9%、+3.7%、 - 55.1%和 - 39.2%。发现与最近的IEEE Std C95.1 - 2005相比，对头部特性几乎不敏感，这与IEEE Std C95.1 - 1999相反。强调考虑组织特性的不确定性对于可植入天线设计和性能评估至关重要。生物电磁学34:167 - 179, 2013。©2012威利期刊公司。
