Projects

In the exploratory phase of this project, we have met our objective to establish a wake sheep animal model for chronic functional testing of neuro-implants. Now, building on this success, the major aims of the proposed project are (1) to realize a fully implantable next-generation µECoG-based device for closed-loop µECoG-based stimulation and recording of brain activity, (2) to evaluate stimulation paradigms capable of either increasing or decreasing brain activity locally and in terms of connectivity in biologically relevant frequency ranges, and (3) to characterize the resulting changes of the animals’ motor behavior using advanced motion capture techniques. Thus, the project will realize a neuro-implant device as a basis for clinical and research applications following both the LiNC and the SEAM concepts. In a joint effort, three BrainLinks-BrainTools branches of expertise together with our strategic partner Bionic Vision Australia (BVA) are going to cooperate in the advanced phase: (1) microsystems engineers from Freiburg and Sydney will cover the development of the next-generation implant following a novel, distributed design principle and with greatly enhanced recording and stimulation capabilities, (2) neurobiologists will establish µECoG closed-loop paradigms and characterize basic principles of modulatory effects, especially on motor-related brain activity. As sheep are also an important large animal model in the Bionic Vision Consortium, parallel animal tests on both sides and exchange of experience will greatly promote our activities in this experimental area. And (3) computer scientist will apply and develop novel and highly sensitive motion capture techniques to quantify the stimulation-dependent motor output changes. We will develop active implants with high channel count electrode arrays for recording and stimulation. Novelty lies in the modular approach to adaptively select electrode channels from modular subsystems of ECoG arrays and to exchange data with these modules through a single extracorporeal telemetry system with a multi-stage coil system. Energy supply will be either delivered via a telemetric link or alternatively by energy harvesting systems that can be connected with the ECoG modules. Knowledge transfer via persons will be performed with our strategic alliance partner Bionic Vision Australia. ECoG recording arrays from BrainLinks-BrainTools will be assessed in conjunction with retinal stimulators from BVA in sheep experiments. Assembling and joining techniques on thin-film based polyimide arrays will be exchanged versus chip scale soldering techniques for hermetic packages with smallest volumes. Subsystems of both groups will be integrated into an implant to investigate the stability of thin-film electrode arrays under stimulation conditions in the central nervous system. In summary, the proposed advanced project will create a first clinically applicable neuro-implant that materializes BrainLinks-Braintools’ eponymous LiNC and to a certain extent also SEAM concepts in a functional, implantable device. Certification and translation to clinics will be cared for in close collaboration with our application centers.