Sang Baek Ryu

• Worked in cross-functional teams to manage and coordinate research projects • Played a pivotal role in the company’s IPO preparation by developing and managing critical technical documentation for investor and regulatory communications

Current project. Behavioral responses to the magnetic stimulation from the chronically-implanted micro-coil • Conducted a stereotaxic surgery to implant recording/stimulating electrodes chronically (or acutely) in mouse (and rat) brain • Tested efficacy of electric and magnetic stimulation of the mouse brain to elicit behavioral responses from awake mice • Performed cardiac perfusion to get brain slices for immunohistology analysis

Project 1. Investigation of cortical response (of the mouse V1) to electric stimulation of the retina - Conducted mouse in-vivo experiments to record neural activities (single-unit activities and local field potentials) from each layer of visual cortex using multi-electrode array. - Tested various stimulation parameters (stimulation amplitude and pulse rates) to check how electrically-evoked RGC responses are transmitted to the visual cortex - Tested the novel stimulation method (sinusoidal waveform) to independently activate different cell types of the retina (ON cells and OFF cells). Project 2. Investigation of spatiotemporal cortical responses to electric and magnetic stimulation - Conducted mouse in-vivo experiments to record μ-ECoG and EEG signal from the cortical surface responding to different stimulation methods (electric vs. magnetic) - Tested whether magnetic stimulation from a micro-coil can elicit a spatially-confined response of the visual cortex - The result was selected as a winner of “The SAC 2021 Poster of Distinction Award” - The result was featured in MGH website (Advances in Motion). (https://advances.massgeneral.org/neuro/journal.aspx?id=1764)

[Medical Device Safety Division] GMP Auditor (ISO 13485, Medical Devices - Quality Management Systems) · Conducted on-site audits at medical device manufacturing sites in more than 10 countries (US, Canada, Japan, China, Russia, India, France, Italy, Sweden, Germany, South Africa, Ireland, Malaysia, Czech, England, etc) Assistant Director (Medical Device Safety Division) · Review of documents on the medical device quality management system (of domestic and foreign medical device manufacturers). · Review of adverse events that occurred while using medical devices. · Review of medical device technical documents.

My research as a graduate student and a postdoctoral researcher in the Neural Engineering Lab is aimed at developing prosthetic stimulation strategies to treat various neurological disorders. (1) Development of electric stimulation strategies for retinal implant · Developed electric stimulation strategies for the retinal implant using a degenerated-retina animal model (rd1 mouse) · Analyzed neuronal activities of retinal ganglion cells (RGCs) recorded from in-vitro experiments · Used various neural decoding algorithms (optimal linear filter, neural network, support vector machine) to verify established stimulation strategies (2) Analysis of neuronal activities from Parkinson's disease model rats · Developed an algorithm for the automatic identification of firing patterns to identify consistent characteristic changes of neuronal activity in basal ganglia (BG) nuclei associated with Parkinson’s disease (PD). · To test the algorithm, a detailed quantitative analysis of firing patterns as well as firing rate was performed in three BG nuclei: the subthalamic nucleus (STN), the substantia nigra pars reticulate (SNpr), and the globus pallidus (GP) recorded from PD model rats and normal rats. (3) Effects of DBS on STN in Parkinson's disease model rats · To study the therapeutic effect of deep brain stimulation (DBS) for Parkinson’s disease (PD), I studied neuronal activities of the globus pallidus (GP) in normal and PD model rats during electrical stimulation of the subthalamic nucleus (STN). I also developed a custom artifact removal technique to observe neuronal activity during stimulation. (4) Therapeutic stimulation for neuropathic pain model rats · Generated neuropathic pain model rats by surgery (spared nerve injury) · Identified neuronal characteristics in a neuropathic pain model rat and studied therapeutic effects of electric stimulation of motor cortex and anterior cingulate cortex.

Thesis: A study on electrical stimulation strategy for the encoding of visual information in neuronal activities of retinal ganglion cells Adviser: Prof. Kyung Hwan Kim