Precise localization of brain tissue causing severe neurological conditions requires subdural recording arrays with high electrode density and low mechanical stiffness compliant with the brain tissue. However, most arrays currently used À such as clinical ECoG grids À are rather stiff and limited in spatial resolution. To overcome these constrains a novel architecture is proposed using delocalized electronic (de)multiplexer grains. Here, their functional units are described in both hard-and software, and tested in simulations and experimentally. The results show that in case of a 100 Â 100 mm ECoG array with lower mechanical stiffness, inter-electrode distances <1 mm can be achieved. Taking parasitic capacitances into account, a signal resolution of 100 μV is reached with an inter-channel timing resolution of 200 ns, which in our model corresponds to tissue localization as precise as 1.2 mm. For clinical application of envisaged 5000 electrodes, a preselection mechanism and routes for adoption of this technology toward cochlear implants and brain computer interfaces are presented. J. P. MarcoletaHearing 4 All Cluster of Excellence Biomaterial Engineering Hannover Medical School

Brain signals such as electroencephalography (EEG) and electrocorticography (ECoG) are used to diagnose epilepsy. ECoG signals are small and therefore require large amplification while keeping the recording electronics small enough to adapt to the surface of the brain. Moreover, the components have to be of low power to reduce the risk of brain damage while recording the brain. Herein, a neuroamplifier that is integrated in an ECoG is described. The amplifier, in combination with a novel multiplexing system that reduces the number of required amplifiers and ensures the flexibility of the ECoG, achieves the desired signal‐to‐noise ratio while reducing power consumption. The feasibility of the proposed design is validated though electronic simulations for different input signals, analyzing the actual amplification achieved and the response times. Moreover the circuit is implemented and real measurements are provided validating the simulations.

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This work presents a novel architecture, exemplified for electrophysiological applications like ECoG that can be used to detect Epilepsy. The new ECoG is based on a mixed analog-digital architecture (Pulse Amplitude Modulation PAM), that allows the use of thousands of electrodes for recording. Whilst the increased number of electrodes helps to refine the spatial resolution of the medical application, the transmission of the signals from the electrodes to an external analysing device appears to be a bottleneck. To overcoming this, our work presents a hardware architecture and corresponding protocol for a mixed architecture that improves the information density between channels and their signal-to-noise ratio. This is shown by the correlation between the input and the transmitted signals in comparison to a classical digital transmission (Pulse Code Modulation PCM) system. We show in this work that it is possible to transmit the signals of 10 channels with a analog-digital architecture with the same quality of a full digital architecture.