Miniaturized Implants to Interface with the Peripheral and Central Nervous System
Event details
| Date | 26.10.2017 |
| Hour | 16:15 › 18:00 |
| Speaker | Prof. Thomas Stieglitz, IMTEK - Institut für Mikrosystemtechnik, University of Freiburg (D) |
| Location | |
| Category | Conferences - Seminars |
CENTER FOR NEUROPROSTHETICS (CNP) SEMINAR
Abstract:
Neural implants need to establish stable and reliable interfaces to the target structure for chronic application in neurosciences as well as in clinical applications. They have to record electrical neural signals, excite neural cells or fibers by means of electrical stimulation. In case of optogenetic experiments, optical stimulation by integrated light sources or waveguides must be integrated on implants. Metabolic monitoring and detection of neurotransmitter concentrations is also part of the research agenda but not yet mature enough for translation in chronic clinical applications. Proper selection of substrate, insulation and electrode materials is of utmost importance to bring the interface in close contact with the neural target structures, minimize foreign body reaction after implantation and maintain functionality over the complete implantation period.
Our work has focused on polymer substrates with integrated thin-film metallization as core of our flexible neural interfaces approach and silicone rubber with metal sheets. Micromachining and laser structuring are the main technologies for electrode array manufacturing. Designing applications for implants in the peripheral and central nervous system needs integration of components, the connection of cables and connectors to both, electrode arrays and hermetic packages containing electronic circuitry for recording, stimulation and signal processing. Failure of one of the components or connections stops the function of the whole system.
We present an exemplary implant system and discuss state of the art materials and manufacturing techniques as well as prominent failure modes. Thin-film substrates and hybrid combinations with silicone rubber substrates serve as neural interfaces. Adhesion layers have been integrated to obtain long term stability of polyimide-platinum sandwiches. Hermetic packages with dozens of electrical feed-throughs need novel approaches to meet the desire of implants with hundreds of electrode channels. Reliability data from long-term ageing studies and chronic experiments show the applicability of thin-film implants for stimulation and recording and ceramic packages for electronics protection. However, system assembly and interfacing microsystems to robust cables and connectors still is a major challenge in translational research and transition of research results into medical products.
Bio:
Thomas Stieglitz (M’95–SM’09) received a Diploma degree in electrical Engineering from Technische Hochschule Karlsruhe, Germany, in 1993, and a PhD and rehabilitation degree in 1998 and 2003 from the University of Saarland, Germany, respectively. In 1993, he joined the Fraunhofer Institute for Biomedical Engineering in St. Ingbert, Germany, where he established the Neural Prosthetics Group. Since 2004, he is a full professor for Biomedical Microtechnology at the Albert-Ludwig-University Freiburg, Germany, in the Department of Microsystems Engineering (IMTEK) at the Faculty of Engineering. He serves as board member and deputy speaker of the Research Cluster of Excellence “BrainLinks-BrainTools”. His research interests include neural interfaces and implants, biocompatible assembling and packaging and brain machine interfaces.
Dr. Stieglitz has co-authored about 100 peer reviewed journal publications, 300 conference proceedings and holds 18 patents. He is co-founder and scientific consultant of CorTec GmbH and neuroloop GmbH, two spin-off companies which focus on neural implant technology and neuromodulation, respectively. Dr. Stieglitz is member of the IEEE EMBS, SfN, the Materials Research Society, founding member of the International Functional Electrical Stimulation Society (IFESS) and member of the German Biomedical Engineering Society (DGBMT im VDE) where he is chair of the Neural Prostheses and Intelligent Implants section.
Abstract:
Neural implants need to establish stable and reliable interfaces to the target structure for chronic application in neurosciences as well as in clinical applications. They have to record electrical neural signals, excite neural cells or fibers by means of electrical stimulation. In case of optogenetic experiments, optical stimulation by integrated light sources or waveguides must be integrated on implants. Metabolic monitoring and detection of neurotransmitter concentrations is also part of the research agenda but not yet mature enough for translation in chronic clinical applications. Proper selection of substrate, insulation and electrode materials is of utmost importance to bring the interface in close contact with the neural target structures, minimize foreign body reaction after implantation and maintain functionality over the complete implantation period.
Our work has focused on polymer substrates with integrated thin-film metallization as core of our flexible neural interfaces approach and silicone rubber with metal sheets. Micromachining and laser structuring are the main technologies for electrode array manufacturing. Designing applications for implants in the peripheral and central nervous system needs integration of components, the connection of cables and connectors to both, electrode arrays and hermetic packages containing electronic circuitry for recording, stimulation and signal processing. Failure of one of the components or connections stops the function of the whole system.
We present an exemplary implant system and discuss state of the art materials and manufacturing techniques as well as prominent failure modes. Thin-film substrates and hybrid combinations with silicone rubber substrates serve as neural interfaces. Adhesion layers have been integrated to obtain long term stability of polyimide-platinum sandwiches. Hermetic packages with dozens of electrical feed-throughs need novel approaches to meet the desire of implants with hundreds of electrode channels. Reliability data from long-term ageing studies and chronic experiments show the applicability of thin-film implants for stimulation and recording and ceramic packages for electronics protection. However, system assembly and interfacing microsystems to robust cables and connectors still is a major challenge in translational research and transition of research results into medical products.
Bio:
Thomas Stieglitz (M’95–SM’09) received a Diploma degree in electrical Engineering from Technische Hochschule Karlsruhe, Germany, in 1993, and a PhD and rehabilitation degree in 1998 and 2003 from the University of Saarland, Germany, respectively. In 1993, he joined the Fraunhofer Institute for Biomedical Engineering in St. Ingbert, Germany, where he established the Neural Prosthetics Group. Since 2004, he is a full professor for Biomedical Microtechnology at the Albert-Ludwig-University Freiburg, Germany, in the Department of Microsystems Engineering (IMTEK) at the Faculty of Engineering. He serves as board member and deputy speaker of the Research Cluster of Excellence “BrainLinks-BrainTools”. His research interests include neural interfaces and implants, biocompatible assembling and packaging and brain machine interfaces.
Dr. Stieglitz has co-authored about 100 peer reviewed journal publications, 300 conference proceedings and holds 18 patents. He is co-founder and scientific consultant of CorTec GmbH and neuroloop GmbH, two spin-off companies which focus on neural implant technology and neuromodulation, respectively. Dr. Stieglitz is member of the IEEE EMBS, SfN, the Materials Research Society, founding member of the International Functional Electrical Stimulation Society (IFESS) and member of the German Biomedical Engineering Society (DGBMT im VDE) where he is chair of the Neural Prostheses and Intelligent Implants section.
Practical information
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