Fully-Passive Wireless Implant for Neuropotential Acquisition: An In Vivo Validation
Fully-Passive Wireless Implant for Neuropotential Acquisition: An In Vivo Validation
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DOI：
10.1109/jerm.2019.2895657
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发表时间：
2019-09-01
影响因子：
3.2
通讯作者：
Volakis, John L.
中科院分区：
文献类型：
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作者：
Moncion, Carolina;Balachandar, Lakshmini;Volakis, John L.
可植入系统通常用于执行神经活动的连续高分辨率记录。这些系统在植入和维持有效操作时经常需要侵入性手术。这对日常生活造成了很大的干扰。以前的工作表明，在体外的最小可检测信号的幅度为15 μ V和RF灵敏度低至-135 dBm。这表明了以无线全被动方式检测微小生物电势的可能性。在这里，我们第一次通过一系列体内电生理记录来验证无线神经传感系统，这些记录包括自发心脏活动和感觉诱发神经活动，其幅度范围从几微伏到毫伏，并且跨越频率谱。我们还提出了设计考虑和神经传感探针的发展，以实现在几十微伏的大鼠生物电位的可检测性。所开发的探头显示出与神经感知系统的阻抗匹配改善。具体而言，新探针显示出比市售探针低几个数量级的阻抗，从而显着改善信号检测。值得注意的是，该技术的体内验证在神经科学中具有巨大的未来临床意义，因为它为神经学研究，监测和治疗目的提供了无线和不显眼的设备。
Implantable systems are often employed to perform continuous high-resolution recordings of neural activity. These systems frequently require invasive procedures when implanting and maintaining effective operation. This causes major interruptions to daily life. Previous work demonstrated an in vitro minimum detectable signal of 15 mu V in amplitude and RF sensitivity down to -135 dBm. This suggests the possibility of detecting diminutive biopotentials in a wireless fully passive manner. Here, for the first time, we validate the wireless neurosensing system through a series of in vivo electrophysiological recordings including both spontaneous cardiac activity and sensory evoked neural activity, with amplitudes ranging from a few microvolts to millivolts and across a spectrum of frequencies. We also present design considerations and the development of probes for neurosensing to accomplish detectability of biopotentials in the tens of microvolts in rats. The developed probes show improved impedance matching with the neurosensing system. Specifically, the new probes showed an impedance several orders of magnitude lower than those commercially available, thereby significantly improving signal detection. Notably, the presented in vivo validation of this technology has great future clinical implications in neuroscience as it offers a wireless and unobtrusive device for neurological research, monitoring, and therapeutic purposes.