Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
J Neural Eng. 2010 Apr;7(2):26004. doi: 10.1088/1741-2560/7/2/026004. Epub 2010 Mar 2.
Brain-machine interfaces (BMIs) use signals recorded directly from the brain to control an external device, such as a computer cursor or a prosthetic limb. These control signals have been recorded from different levels of the brain, from field potentials at the scalp or cortical surface to single neuron action potentials. At present, the more invasive recordings have better signal quality, but also lower stability over time. Recently, subdural field potentials have been proposed as a stable, good quality source of control signals, with the potential for higher spatial and temporal bandwidth than EEG. Here we used finite element modeling in rats and humans and spatial spectral analysis in rats to compare the spatial resolution of signals recorded epidurally (outside the dura), with those recorded from subdural and scalp locations. Resolution of epidural and subdural signals was very similar in rats and somewhat less so in human models. Both were substantially better than signals recorded at the scalp. Resolution of epidural and subdural signals in humans was much more similar when the cerebrospinal fluid layer thickness was reduced. This suggests that the less invasive epidural recordings may yield signals of similar quality to subdural recordings, and hence may be more attractive as a source of control signals for BMIs.
脑机接口 (BMI) 使用直接从大脑记录的信号来控制外部设备，如计算机光标或假肢。这些控制信号已经从大脑的不同层次记录下来，从头皮或皮质表面的场电位到单个神经元动作电位。目前，侵入性更强的记录具有更好的信号质量，但随着时间的推移稳定性也较低。最近，硬膜下场电位被提出作为一种稳定、高质量的控制信号源，具有比 EEG 更高的空间和时间带宽潜力。在这里，我们使用大鼠和人类的有限元建模以及大鼠的空间频谱分析，比较了硬膜外（硬脑膜外）记录的信号与从硬膜下和头皮位置记录的信号的空间分辨率。在大鼠中，硬膜外和硬膜下信号的分辨率非常相似，在人体模型中则稍差一些。两者都明显优于头皮记录的信号。当脑脊液层厚度减小时，硬膜外和硬膜下信号在人类中的分辨率更为相似。这表明，侵入性较小的硬膜外记录可能会产生与硬膜下记录相似质量的信号，因此作为 BMI 的控制信号源可能更具吸引力。
