Design and implementation of monolithic integrated electronic devices for the control and recordingof bidirectional multi-electrode arrays.

该研究项目调查了同时刺激和记录视网膜神经细胞的可能性。这将通过穿透视网膜所有层的多电极阵列（MEA）来实现。本项目中设计的MEA每个穿透杆将有一个以上的电极。每个电极可以选择为刺激电极或记录电极，从而允许在小区域组织内同时刺激和记录。从工程学的角度来看，由于可以刺激不同深度的组织，它可以在设计更好的植入物方面取得突破。基于所分析的组织的自动刺激参数适配将是可能的。 在项目的第一阶段，MEA中电极尺寸的大幅减小证明了众所周知的刺激技术无法在不造成损害的情况下使用。已经发明了一种新的刺激技术来规避这个问题，并允许使用具有小面积电极的MEA安全地刺激视网膜。根据项目总体描述的要求，新的刺激方法是专门针对视网膜双极细胞设计的，项目第二阶段的目标是首先完成第一阶段资金结束时收到的记录和刺激芯片以及电流电极阵列的功能验证。其次，任意刺激信号的生成将被纳入新刺激技术并在新刺激器IC中实现。我们的合作伙伴对不同细胞层的细胞生物学实验结果进行了详细阐述，将为新刺激器芯片的规格奠定基础。第三，将与分项目C和D的生物医学实验人员一起研究以下问题：-是否有可能使用新的刺激技术刺激不同类型的视网膜神经细胞并同时记录它们的活动？是否还可以限制刺激空间参数或在刺激期间调整调制概念？是否有任何特定于层的刺激波形和参数可以导致与层和位置相关的最佳行为？产生这些波形的最好方法是什么？结果将指导CMOS芯片的设计，执行任意刺激以及记录功能。在项目期间，A小组将实施这种具有二维基本结构的四个穿透柄的芯片。在项目的最后三分之一期间，它将作为多参数配置测试板提供给分组C和D。

The research project investigates the possibility of simultaneously stimulating and recording neural cells of the retina. This will be achieved by a multi-electrode array (MEA) that penetrates through all layers of the retina. The MEAs designed within this project will have more than one electrode per penetrating shank. Each electrode can be selected as either a stimulating or recording electrode, thereby allowing simultaneous stimulation and recording within a small area of tissue. From an engineering perspective it can present a breakthrough in the design of better implants due to the possibility of stimulation of different depths of tissue. An automatic stimulation parameter adaption based on the analyzed tissue will be possible. In the first phase of the project, the much reduced size of the electrodes in the MEA has proven that well-known stimulation techniques cannot be used without causing damage. A new stimulation technique has been invented to circumvent this problem and to permit safe stimulation of the retina using MEAs with small area electrodes. As required by the general project description, the new stimulation method is specifically designed to target retinal bipolar cells.The objectives of the proposed second phase of the project are firstly to complete the functional verification of the recording and stimulation chips, received at the end of the first funding phase, together with the current electrode array. Secondly, the generation of arbitrary stimulation signals will be included into the new stimulation technique and implemented in the new stimulator IC. The results of cell-biologic experiments on different cell layers, elaborated by our partners, will form the base for the specification of the new stimulator chip. Thirdly, together with the biomedical experimenters of subproject C and D the following questions will to be investigated:- Is it possible to stimulate different types of retinal nerve cells using the new stimulation technique and record their activity simultaneously? Is it also possible to limit the stimulation space parameters or to adapt the modulation concept during stimulation?- Are there any layer-specific stimulus waveforms and parameters which result in best behavior in relation to layer and place? What ist the best way of generating these waveforms?The results will guide the design of a CMOS-chip which performs the arbitrary stimulation as well as the recording functionality. During the project subgroup A will implemented this chip with a two dimensional basic structure for four penetrating shanks. It will be provided to subgroups C and D as a multi parameter configuration test board during the last third of the project.