Rossel Olivier, Soulier Fabien, Bernard Serge, Cathébras Guy
Laboratoire d’Informatique de Robotique et de Micro´electronique de Montpellier, 161 rue Ada, 34392 Montpellier, France.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:5843-6. doi: 10.1109/IEMBS.2011.6091445.
In the context of functional electrical stimulation, neural recording is one of the main issues. For instance, the control of the limbs in people with motor deficiencies needs information about the muscle lengths and speeds that can be extracted from electroneurograms (ENG) carried on afferent peripheral nerves. The aim of this study is to propose an non-invasive and spatial-selective electrode (because specific informations are carried into different fascicles). To do so, we investigate the spatial properties of an extracellular action potential (AP). This properties are described qualitatively and quantitatively using analytical study on an inhomogeneous an anisotropic nerve model. Then, a spectral analysis on this spatial signal discriminates the different frequency components. Low spatial frequencies represent the global shape of the signal, whereas high frequencies are related to the type of fibers. We show that the latter is rapidly attenuated with the distance and thus, being a local phenomenon, can be used as a selective measurement. Finally, we propose a spatial filtering based on electrode design and an electronic architecture to extract this high frequencies.
在功能性电刺激的背景下，神经记录是主要问题之一。例如，运动功能缺陷患者的肢体控制需要有关肌肉长度和速度的信息，这些信息可从传入外周神经上记录的肌电图（ENG）中提取。本研究的目的是提出一种非侵入性的空间选择性电极（因为特定信息承载于不同的神经束中）。为此，我们研究细胞外动作电位（AP）的空间特性。利用对非均匀各向异性神经模型的分析研究，对这些特性进行了定性和定量描述。然后，对该空间信号进行频谱分析，以区分不同的频率成分。低空间频率代表信号的整体形状，而高频率与纤维类型有关。我们表明，后者随距离迅速衰减，因此作为一种局部现象，可用于选择性测量。最后，我们提出一种基于电极设计和电子架构的空间滤波方法来提取这些高频成分。
