INCRIMP

The subject of the project is the development of essential microsystems technology and microelectronic components and designs for the construction of a multi-channel system with wireless energy and signal transmission that can be completely implanted in the skull for safe electrophysiological and neurochemical long-term monitoring and electrical modulation of brain function. The later versions of the modular, multifunctional implant system enable intracranial long-term EEG measurement, multi-channel microstimulation and the electrochemical detection of neurochemical substances.

Measuring the electrical activity of the brain, known as electroencephalography (EEG), is a standard method for diagnosing and monitoring disorders of the central nervous system. Examples are epilepsy, sleep disorders and impaired consciousness caused by brain lesions. The use of brain-computer interfaces for rehabilitation in the case of motor dysfunctions, which is currently being tested clinically, is also based on the registration of electroencephalograms (also abbreviated to EEG). Accurate epilepsy diagnosis requires continuous EEG measurement over several hours to weeks. The recording can be stationary or telemetric with partial freedom of movement within a station. In the context of presurgical epilepsy diagnostics in patients with drug-resistant epilepsies, invasive recordings with implanted electrodes are also performed in order to obtain additional information about the spatial and temporal development of the epileptic discharges. During the invasive derivation, which lasts an average of 7 to 14 days, the patients are in an intensive care unit. During this time there is an increased risk of complications (infections, bleeding) due to the insertion of the electrodes and the existing cable connections through the skull and skin to the outside. From a medical point of view, longer-lasting EEG derivations are desirable, but often not feasible with the current state of the electrode and derivation technology.

Recent therapeutic approaches aim to suppress the spread of epileptic activity through targeted microstimulation of cerebral structures. This requires the permanent implantation of a system for recording and stimulating brain activity. Because neurological disorders can also result from disturbances in biochemical balance, the ability to measure "brain chemistry" is desirable. This requires suitable, chemically inert electrodes and implants with the appropriate functionality for long-term use.

In order to solve the various tasks, a system that can be completely implanted in the skull is being developed. The system is based on universal electrodes that can be used for various applications. The developments in microsystems technology include the appropriate carbon-based microelectrodes (carbon nanotubes), which are integrated into flexible, large-area polymer substrates, as well as innovative microelectronic approaches for data acquisition and telemetry, as well as solutions for assembly and connection technology. A system for intracranial EEG recordings and a suitable implantation method are being developed as examples for other applications.