The mechanism by which the neural networks communicate and the understanding of these processes remains the fundamental issue of neuroscience. Long-term brain activity registration and stimulation is the main ally to analyze and interpret data coming from the brain. Several materials and microelectronics techniques have been pursued to obtain reliable and long lasting implantable devices from intracortical electrodes to soft epicortical arrays. Among them, ultra-flexible interfaces result particular appealing for their superior conformability and intimate contact with the brain tissue, especially for epicortical devices, thus achieving higher signals and reducing brain injuries. By other side, also external electronics is important properly to treat the signal, filtering the artifacts and minimizing the noise. In this paper, a novel compact integrated system for both brain stimulation and recording is presented. The device consisted in an ultra-flexible polyimide 32-channel microelectrodes array (8 um thick) connected to a miniaturized PCB able to amplify, filter and digitalize the neural signals. The size of this acquiring board is 60x45 mm and it provides an amplification of 200x with a sampling rate greater than 1 MSamples/s. The system has been successfully tested both in-vivo and invitro experiments on Wistar rat demonstrating that it could be a good candidate for a further miniaturization of the measurement equipment.
1 Apr 2015
B DEBATE-A Dialogue with the Cerebral Cortex: Cortical Function and Interfacing (Workshop), Barcelona, Spain