Hyunjoo J Lee
KAIST, Korea
Title: Biomedical microsystem for neuro interface: Monitoring, stimulations, and its application in brainmachine interface
Biography
Biography: Hyunjoo J Lee
Abstract
Statement of the Problem: In the current ageing society, the number of people affected by neurodegenerative brain diseases is rapidly increasing, yet, there is no effective therapeutics for many of these brain disorders. To find an effective treatment, a brain probing system with multiple functions such as light stimulation, multi-channel recording and drug delivery is essential. Furthermore, such system will eventually lead to an effective brain-machine interface and neuroprosthetic systems. In addition to brain monitoring, non-invasive brain stimulation with high spatial resolution will be an important integral part of a brain-machine interface to enhance cognition and mobility in the future. Thus, modulating the brain through physical stimulation, such as transcranial magnetic stimulation (TMS) and direct current stimulation (tDCs) have been actively researched.
Methodology & Theoretical Orientation: Because of insufficient understanding of the brain, we have developed brain recording and stimulation systems for in vivo small animal experiments first. We developed a multi-functional probe based on silicon micromachining technology that records the brain signals from multiple locations and stimulates the brain using drugs and light simultaneously. In addition, for in vivo small animal experiments, stimulation using a commercial ultrasound transducer is subject to several limitations because of its large size and heavy weight. Thus, we also developed a new light-weight ultrasound transducer based on Capacitive Micromachined Ultrasonic Transducers (CMUT) technology. The transducer array is designed in a ring shape in order to achieve natural single focus without the needs for beam forming.
Findings: The developed microsystems can successfully stimulate the brain invasively using optogenetics and drug delivery while recording individual neuronal spies at multiple locations, as well as non-invasively stimulate brain using ultrasound.
Conclusion & Significance: The presented neuromicrosystems will be an enabling tool that facilitates the advance of research in functional brain mapping, therapeutics for brain disorders and brain-machine interface.