Development of an integrated control system for external devices using neural information

本项目的目标是获得一种可以像患者控制自己的肢体一样用运动信息控制的假肢系统或轮椅，并实现由自主神经信息控制的人工心脏系统。我们的重点是(A)开发一种能够长期测量神经信号的记录系统，(B)在了解外部设备的特性的过程中对神经系统进行分析，以及(C)开发一种利用神经信息的外部设备的集成控制系统。我们开发了各种柔性神经探针，具有足够的灵活性，可以使用柔性薄膜实现微创交错。作为第一步，我们专注于生产用于探针的柔性衬底。然后重点研究了整个神经探头结构的灵活性。我们通过使用对二甲苯实现了这一点。通过握住探头的尖端，电极能够完全灵活地进行三维记录。由于该探针太过柔韧，不能插入神经组织中，我们提出了一种新的插入方法，使用聚乙二醇包覆材料。然后，我们开发了柔性探头，探头中集成了微流控通道，可以用于向神经组织中注入药物或基因等各种材料，并实现与神经系统的稳定接口。然后，我们开发了一种集成控制系统，其中车辆由来自大鼠初级运动皮质的神经信号控制。我们通过初级运动皮质的加权放电率来估计一只大鼠的行走速度。我们还开发了一个利用兔和山羊的自主神经信息来控制人工心脏的系统。

The goal of this project is to attain an artificial limb system or a wheelchair that can be controlled with motor information in the same way as patients control their own limbs and also to realize an artificial heart system controlled by autonomic nerve information. We focused on (A) development of a recording system capable of measuring neural signals chronically, (B) analysis of neural system during learning the property of external devices and (C) development of an integrated control system for external devices using neural information.First we developed a recording system. We developed various flexible neural probes with sufficient flexibility to achieve minimally invasive interlacing using flexible films. As the first step, we focused on producing a flexible substrate for the probes. Then we focused on the flexibility of the whole neural probe structure. We achieved this by using parylene. By holding the tip of the probes, the electrode became capable of three-dimensional recording with complete flexibility. As the probe was too flexible to be inserted into neural tissues, we proposed a new method of insertion using polyethylene glycol (PEG) as the coating material. Then we developed flexible probes that had micro-fluidic channels integrated into the probe that can be used to inject various materials such as medicines or genes into neural tissues and achieve a stable interface with the nervous system.Then we developed an integrated control system in which a vehicle was controlled by the neural signals from the primary motor cortex of a rat. We estimated the walking speed of a rat by the weighted firing rates in the primary motor cortex. We also developed a control system for an artificial heart using autonomic nerve information of rabbits and goats.