Autonomous control for mechanically stable navigation of microscale implants in brain tissue to record neural activity.
Autonomous control for mechanically stable navigation of microscale implants in brain tissue to record neural activity.
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DOI：
10.1007/s10544-016-0093-8
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发表时间：
2016-08
影响因子：
2.8
通讯作者：
Muthuswamy J
中科院分区：
文献类型：
--
作者：
Anand S;Kumar SS;Muthuswamy J
新兴的神经假体需要精确的位置调整和稳定的界面与单个神经元的最佳功能在一生中。在这项研究中，我们报告了一种自主控制，以精确导航微尺度电极在软，粘弹性脑组织没有视觉反馈。自主控制优化了粘弹性脑组织中单个神经元记录的信噪比（SNR），同时保持准静态机械应力条件，以提高植入物-组织界面的稳定性。力-位移曲线从微电极在体内啮齿动物实验中被用来估计大脑的粘弹性参数。使用计算模型和实验的组合，我们确定了微电极的最佳运动，其中双向位移的向前和向后位移之间的比率为3：2，并且运动间隔为40秒，以最大限度地减少周围脑组织中的机械应力。与使用常规线性单向微电极移动的调节器（具有1.48次移动/min和稳定SNR 23%的时间）相比，在体内实验中具有用于微电极的上述最佳双向运动的调节器导致微电极移动的数量显著减少（0.23次移动/min）和稳定SNR的更长时间（53%的时间）。
Emerging neural prosthetics require precise positional tuning and stable interfaces with single neurons for optimal function over a lifetime. In this study, we report an autonomous control to precisely navigate microscale electrodes in soft, viscoelastic brain tissue without visual feedback. The autonomous control optimizes signal-to-noise ratio (SNR) of single neuronal recordings in viscoelastic brain tissue while maintaining quasi-static mechanical stress conditions to improve stability of the implant-tissue interface. Force-displacement curves from microelectrodes in in vivo rodent experiments are used to estimate viscoelastic parameters of the brain. Using a combination of computational models and experiments, we determined an optimal movement for the microelectrodes with bidirectional displacements of 3:2 ratio between forward and backward displacements and a inter-movement interval of 40 sec for minimizing mechanical stress in the surrounding brain tissue. A regulator with the above optimal bidirectional motion for the microelectrodes in in vivo experiments resulted in significant reduction in the number of microelectrode movements (0.23 movements/min) and longer periods of stable SNR (53% of the time) compared to a regulator using a conventional linear, unidirectional microelectrode movement (with 1.48 movements/min and stable SNR 23% of the time).