Final Report Summary - µTHALYS (Micro-Technologies and Heterogeneous Advanced Platforms for Implantable Medical Systems)
The general aim of our ERC project ‘µThalys’, acronym that stands for Micro-Technologies and Heterogeneous Advanced Platforms for Implantable Medical Systems, is to shift frontiers of the comfort of implantable monitoring devices for health. As the detailed title mentions, it does this by implementing state-of-the-art technologies in microfabrication. Basis for the project is the existing experience in implants and sensors of the PI, and the endeavor to expand it with a new combination of materials with focus on more flexible and stretchable geometries of the implants. The excellent cooperation with clinical experts of the University Hospital from Leuven has enabled major breakthroughs in mainly Urology and Neurology. In the former discipline, two new implant systems have been developed. In the first place, a miniature, flexible, fully autonomous capsule for bladder pressure monitoring (called the Bladder Pill) has been successfully demonstrated in animals, opening the path to human trials. The system allows to overcome the uncomfortable monitoring via a catheter, and enables stress free 48h monitoring. A second, more exploratory sensor network has been developed intended to better understand the working of the human bladder. It will provide an answer on the, still unsolved, question on what mechanism provides the urge feeling. To this purpose, a multi-sensor network, consisting of pressure sensors, accelerometers and recording electrodes has been created as a fully stretchable spider-like structure to fit the exterior wall of the bladder. It monitors the wall on four distinct locations. The materials and geometries adopted allow the organ to naturally and freely expand its typical track (from 0 ml up to 600 ml), despite the fact it is enveloped by this sensor network. Recent animal implant tests have revealed entirely new insights in the operation of the organ and are currently sent for publication. It is clear that the results are adoptable to other organ applications without major modifications. In conjunction, the packaging and sealing techniques have been tested for fatigue, as well as biocompatibility and long term operation in living tissue.
In the Neurological application field, an important part of the research was dedicated to the applicability of controlled release and coating of the surface of the implants to avoid scar tissue formation. Successful long term implant tests with novel flexible electrodes have demonstrated this. Our team has developed a series of extremely flexible neural electrodes for brain research, which are smaller in cross-section than a single cell and are inserted in the brain carried in a dissolving microneedle. We have demonstrated that they work reliable for action potential recording for prolonged periods (> one year). The project has also allowed to design a chip for readout out large amounts of channels (256, and 4096 in a future version), and to work on the integration of the chip in brain implants. Another world first brain implant is a fully 3D self-expanding brain electrode to be capable to record activity in an abnormal brain cavity (arising e.g. due to stroke). The positive results have enabled new contacts and cooperation, e.g. with the Nerf research center and recently with yet another research group to restore vision by direct stimulation of the visual cortex. The experience on inertial sensors and its packaging technology has also been adopted to different research groups, e.g. in Cardiology to monitor cardiac output. So it is clear that new projects and animal studies are under way, as a spin-out of the expertise gained in µThalys. To conclude, the project was an important milestone in the development of medical implants that seamlessly integrate with the body.
In the Neurological application field, an important part of the research was dedicated to the applicability of controlled release and coating of the surface of the implants to avoid scar tissue formation. Successful long term implant tests with novel flexible electrodes have demonstrated this. Our team has developed a series of extremely flexible neural electrodes for brain research, which are smaller in cross-section than a single cell and are inserted in the brain carried in a dissolving microneedle. We have demonstrated that they work reliable for action potential recording for prolonged periods (> one year). The project has also allowed to design a chip for readout out large amounts of channels (256, and 4096 in a future version), and to work on the integration of the chip in brain implants. Another world first brain implant is a fully 3D self-expanding brain electrode to be capable to record activity in an abnormal brain cavity (arising e.g. due to stroke). The positive results have enabled new contacts and cooperation, e.g. with the Nerf research center and recently with yet another research group to restore vision by direct stimulation of the visual cortex. The experience on inertial sensors and its packaging technology has also been adopted to different research groups, e.g. in Cardiology to monitor cardiac output. So it is clear that new projects and animal studies are under way, as a spin-out of the expertise gained in µThalys. To conclude, the project was an important milestone in the development of medical implants that seamlessly integrate with the body.