Perez Felipe P, Rahmani Maryam, Morisaki Jorge, Amran Farhan, Bakri Syazwani, Halim Akmal, Dsouza Alston, Yusuff Nurafifi Mohd, Farhan Amran, Maulucci James, Rizkalla Maher
Department of Medicine, Division of General Internal Medicine and Geriatrics, Indiana University School of Medicine, Indianapolis, USA.
Department of Electrical and Computer Engineering, Indiana University-Purdue University, Indianapolis, USA.
J Biosci Med (Irvine). 2023 Feb;11(2):177-185. doi: 10.4236/jbm.2023.112013.
Alzheimer's disease (AD) is a brain disorder that eventually causes memory loss and the ability to perform simple cognitive functions; research efforts within pharmaceuticals and other medical treatments have minimal impact on the disease. Our preliminary biological studies showed that Repeated Electromagnetic Field Stimulation (REFMS) applying an EM frequency of 64 MHz and a specific absorption rate (SAR) of 0.4 - 0.9 W/kg decrease the level of amyloid- peptides (A), which is the most likely etiology of AD. This study emphasizes uniform E/H field and SAR distribution with adequate penetration depth penetration through multiple human head layers driven with low input power for safety treatments. In this work, we performed numerical modeling and computer simulations of a portable Meander Line antenna (MLA) to achieve the required EMF parameters to treat AD. The MLA device features a low cost, small size, wide bandwidth, and the ability to integrate into a portable system. This study utilized a High-Frequency Simulation System (HFSS) in the design of the MLA with the desired characteristics suited for AD treatment in humans. The team designed a 24-turn antenna with a 60 cm length and 25 cm width and achieved the required resonant frequency of 64 MHz. Here we used two numerical human head phantoms to test the antenna, the MIDA and spherical head phantom with six and seven tissue layers, respectively. The antenna was fed from a 50-Watt input source to obtain the SAR of 0.6 W/kg requirement in the center of the simulated brain tissue layer. We found that the E/H field and SAR distribution produced was not homogeneous; there were areas of high SAR values close to the antenna transmitter, also areas of low SAR value far away from the antenna. This paper details the antenna parameters, the scattering parameters response, the efficiency response, and the E and H field distribution; we presented the computer simulation results and discussed future work for a practical model.
阿尔茨海默病（AD）是一种脑部疾病，最终会导致记忆丧失以及执行简单认知功能的能力下降；制药和其他医学治疗方面的研究努力对该疾病的影响微乎其微。我们的初步生物学研究表明，重复电磁场刺激（REFMS）施加64兆赫兹的电磁频率和0.4 - 0.9瓦/千克的比吸收率（SAR）可降低淀粉样肽（A）的水平，而淀粉样肽是AD最可能的病因。本研究强调均匀的电场/磁场（E/H）场和比吸收率分布，以及在低输入功率驱动下通过多层人体头部实现足够的穿透深度以进行安全治疗。在这项工作中，我们对便携式曲折线天线（MLA）进行了数值建模和计算机模拟，以实现治疗AD所需的电磁场参数。MLA设备具有低成本、小尺寸、宽带宽以及能够集成到便携式系统中的特点。本研究在设计适合人类AD治疗的具有所需特性的MLA时使用了高频仿真系统（HFSS）。该团队设计了一个24匝的天线，长度为60厘米，宽度为25厘米，并实现了所需的64兆赫兹谐振频率。在这里，我们使用了两种数值人体头部模型来测试天线，分别是具有六层和七层组织层的MIDA和球形头部模型。天线由一个50瓦的输入源馈电，以在模拟脑组织层中心获得0.6瓦/千克的比吸收率要求。我们发现产生的电场/磁场（E/H）场和比吸收率分布不均匀；靠近天线发射器处有高比吸收率值区域，远离天线处也有低比吸收率值区域。本文详细介绍了天线参数以及散射参数响应、效率响应和电场与磁场分布；我们展示了计算机模拟结果并讨论了实际模型的未来工作。
