Perez Felipe, Morisaki Jorge, Kanakri Haitham, Rizkalla Maher, Abdalla Ahmed
IU School of MedicineIndiana University Indianapolis IN 46202 USA.
REMFS LLC Indianapolis IN 46278 USA.
IEEE J Transl Eng Health Med. 2025 Apr 10;13:158-173. doi: 10.1109/JTEHM.2025.3559693. eCollection 2025.
Late Onset Alzheimer's Disease (LOAD) is the most common cause of dementia, characterized by the deposition of plaques primarily of neurotoxic amyloid-[Formula: see text] ([Formula: see text]) peptide and tau protein. Our objective is to develop a noninvasive therapy to decrease the toxic A[Formula: see text] levels, using repeated electromagnetic field stimulation (REMFS) in the brain of Alzheimer's disease patients. We previously examined the effects of REMFS on [Formula: see text] levels in primary human brain (PHB) cultures at different frequencies, powers, and specific absorption rates (SAR). PHB cultures at day in vitro (DIV7) treated with 64 MHz with a SAR of 0.6 W/Kg, one hour daily for 14 days (DIV 21) had significantly reduced (p =0.001) levels of secreted [Formula: see text]-42 and [Formula: see text]-40 peptide without evidence of toxicity. The EMF frequency and power, and SAR levels used in our work is utilized in MRI's, thus suggesting REMFS can be further developed in clinical settings to lower ([Formula: see text]) levels and improve the memory in AD patients. These findings and numerous studies in rodent AD models prompted us to design a portable RF device, appropriate for human use, that will deliver a homogeneous RF power deposition with a SAR value of 0.4-0.9 W/kg to all human brain memory areas, lower ([Formula: see text]) levels, and potentially improve memory in human AD patients.The research took place at the Indiana University School of Medicine (IUSM) and Purdue University Indianapolis. The first phase was done in PHB cultures at the IUSM. Through this phase, we found that a 64 MHz frequency and an RF power deposition with a SAR of 0.4-0.6 W/kg reduced the (A[Formula: see text]) levels potentially impacting Alzheimer's disease. The second phase of the project was conducted at Purdue University, we used ANSYS HFSS (High Frequency Simulation System) to design the devices that produced an appropriate penetration depth, polarization, and power deposition with a SAR of 0.4-0.9 W/kg to all memory brain areas of several numerical models. In Phase II-B will validate the device in a physical phantom. Phase III will require the FDA approval and application in clinical trials.The research parameters were translated into a designed product that fits comfortably in human head and fed from an external RF source that generates an RF power deposition with a SAR of 0.4-0.9 W/kg to a realistic numerical brain. The engineering design is flexible by varying the leg capacitors of the Meander Line Antenna (MLA) devices. Thermal outcomes of the results guarantee less than 0.5 C temperature increase within one-hour time of exposure, which can be used in clinical trials for AD patients. Design parameters include dimension of the coil, the MLA structure, conducting material, and capacitance values with the produced EM fields. The flexible design was achieved by varying the additive capacitance between conductors, and via a hybrid approach integrating a birdcage with sixteen MLA. A coil antenna size within 16 cm radius and 13 cm length was achieved. A capacitance between 6.9 nF and 9.2 nF were observed when copper materials with 16 conductors were used to achieve the research parameters in focus.The medical project proposed here has three phases: The initial phase of determining the research parameters for reducing A[Formula: see text] levels in human brain cultures and animal studies was completed at the IUSM. The translational engineering design of the REMS device and the numerical head and Antenna devices was successfully completed and presented in this paper by Purdue University and IUSM. Future phases will require manufacture and experimental validation of the REMS device with FDA approval for human application. Clinical impact: Our biological studies in human brain cultures showed that an RF power with a SAR of 0.4-0.9 W/kg at 64 MHz, lowered A[Formula: see text] levels, which potentially will prevent the death of the brain neurons and improve memory in AD. The fact that we found a safe RF power deposition with a SAR value associated with the proposed biological effects in human neurons and that 64 MHz provides a penetration depth of 13.5 cm that reaches all memory areas in a human brain makes the design and manufacture of this device of high clinical impact in the study of these exposures on the treatment of Alzheimer's and other protein associate diseases. Also, 64 MHz and RF power deposition with similar SAR levels are administer routinely in routine MRI for more than 4 decades makes it a safe framework for these novel therapeutic strategy.Clinical and Translational Impact Statement: The basic science work presented previously is both mechanistic and translational, and would advance the field of neuroscience as well as AD. This prompted us to joint efforts between the Indiana University School of Medicine and the electrical and computer engineering at Purdue University to design and develop a suitable EMF device for human treatments. Recently, our engineering team designed a birdcage antenna that generate a homogeneous RF power deposition with the same SAR values of our biological experiments in a realistic numerical human brain. Here, the engineering research has been extended to investigate the design of a portable flexible birdcage antenna that will enable adjustments to fit physical patient's characteristics, such as geometry, head size, and tissue dimensions. This new device is expected to improve SAR uniformity and may reduce the likelihood of untreated regions in the brains of patients during treatments. Also, here we determined that the maximum temperature rise of these exposures was less than 0.5°C, which is a safe level per regulatory agencies. This study considers a portable device system that will achieve the research parameters and patient satisfaction regarding reliability and comfort.
晚发性阿尔茨海默病(LOAD)是痴呆最常见的病因,其特征是主要由神经毒性淀粉样β蛋白(Aβ)肽和tau蛋白沉积形成斑块。我们的目标是开发一种非侵入性疗法,通过对阿尔茨海默病患者大脑进行重复电磁场刺激(REMFS)来降低有毒Aβ水平。我们之前研究了不同频率、功率和比吸收率(SAR)下REMFS对原代人脑(PHB)培养物中Aβ水平的影响。体外培养第7天(DIV7)的PHB培养物,以0.6W/Kg的SAR在64MHz频率下处理,每天1小时,共14天(DIV 21),分泌的Aβ-42和Aβ-40肽水平显著降低(p =0.001),且无毒性迹象。我们研究中使用的电磁场频率、功率和SAR水平在磁共振成像(MRI)中也会用到,这表明REMFS在临床环境中可以进一步开发,以降低Aβ水平并改善AD患者的记忆力。这些发现以及在啮齿动物AD模型中的大量研究促使我们设计一种适合人类使用的便携式射频设备,该设备将向人类大脑所有记忆区域提供均匀的射频功率沉积,SAR值为0.4 - 0.9W/kg,降低Aβ水平,并有可能改善人类AD患者的记忆力。该研究在印第安纳大学医学院(IUSM)和印第安纳波利斯普渡大学进行。第一阶段在IUSM的PHB培养物中完成。通过这一阶段,我们发现64MHz频率和0.4 - 0.6W/kg SAR的射频功率沉积可降低可能影响阿尔茨海默病的Aβ水平。该项目的第二阶段在普渡大学进行,我们使用ANSYS HFSS(高频仿真系统)设计设备,该设备能对多个数值模型的所有记忆脑区产生合适的穿透深度、极化和功率沉积,SAR为0.4 - 0.9W/kg。在II - B阶段将在物理模型中验证该设备。第三阶段将需要美国食品药品监督管理局(FDA)批准并应用于临床试验。研究参数被转化为一种设计产品,该产品能舒适地贴合人类头部,并由外部射频源供电,该射频源能向逼真的数值大脑产生0.4 - 0.9W/kg SAR的射频功率沉积。通过改变曲折线天线(MLA)设备的腿部电容,工程设计具有灵活性。结果的热效应保证在暴露1小时内温度升高小于0.5℃,这可用于AD患者的临床试验。设计参数包括线圈尺寸、MLA结构、导电材料以及所产生电磁场的电容值。通过改变导体之间的附加电容,并通过将鸟笼与十六个MLA集成的混合方法实现了灵活设计。实现了半径16cm、长度13cm的线圈天线尺寸。当使用16根导体的铜材料来实现重点研究参数时,观察到电容在6.9nF至9.2nF之间。这里提出的医学项目有三个阶段:确定降低人脑培养物和动物研究中Aβ水平的研究参数的初始阶段在IUSM完成。普渡大学和IUSM成功完成并在本文中展示了REMS设备以及数值头部和天线设备的转化工程设计。未来阶段将需要制造并通过FDA批准用于人体应用的REMS设备进行实验验证。临床影响:我们在人脑培养物中的生物学研究表明,64MHz下0.4 - 0.9W/kg SAR的射频功率可降低Aβ水平,这可能会预防脑神经元死亡并改善AD患者的记忆力。我们发现与人类神经元中提出的生物学效应相关的SAR值的安全射频功率沉积,并且64MHz提供13.5cm的穿透深度,可到达人类大脑的所有记忆区域,这使得该设备的设计和制造在研究这些暴露对阿尔茨海默病和其他蛋白质相关疾病的治疗中具有很高的临床影响。此外,40多年来,64MHz和具有类似SAR水平的射频功率沉积在常规MRI中常规使用,这使其成为这些新型治疗策略的安全框架。临床与转化影响声明:之前展示的基础科学工作既有机制性又有转化性,将推动神经科学以及AD领域的发展。这促使我们在印第安纳大学医学院与普渡大学的电气与计算机工程系之间共同努力,设计和开发一种适合人体治疗的电磁场设备。最近,我们的工程团队设计了一种鸟笼天线,该天线在逼真的数值人脑模型中产生与我们生物学实验相同SAR值的均匀射频功率沉积。在此,工程研究已扩展到研究一种便携式灵活鸟笼天线的设计,该天线将能够进行调整以适应物理患者的特征,如几何形状、头部大小和组织尺寸。这种新设备有望提高SAR均匀性,并可能降低治疗期间患者大脑中未治疗区域的可能性。此外,我们在此确定这些暴露的最大温度升高小于0.5℃,这是监管机构规定的安全水平。本研究考虑了一种便携式设备系统,该系统将实现研究参数以及患者对可靠性和舒适度的满意度。