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In this article, we present electrochemical interrogation for collision dynamics of electrogenerated individual polybromide ionic liquid (PBIL) droplets through chronoamperometry combined with fast scan cyclic voltammetry (CA-FSCV). In the CA mode of CA-FSCV, a Pt ultramicroelectrode (UME) acts as the electrochemical generator for PBIL droplets by holding the oxidation potential for Br– in a given time, while FSCV is repetitively performed at a certain frequency. In the FSCV mode of CA-FSCV, a Pt UME serves as the probe to electrochemically monitor Br3– reduction for an adsorbed PBIL droplet during collision with a high temporal resolution. Based on the newly introduced CA-FSCV, we can estimate the dynamic changes in the following parameters for a short collision time: the contact radius of a PBIL droplet on a Pt UME, the concentration of Br– in the droplet, and the apparent charge transfer rate constant for electro-reduction of Br3– to Br– in the droplet, koapp. Moreover, a computational calculation using molecular dynamics is presented that can explain the change in koapp as a function of time for Br– electrolysis in a PBIL droplet. Based on the quantitative estimation of the above parameters, we suggest a more advanced mechanism for the stochastic electrochemical collision process of a PBIL droplet. These findings are important for understanding QBr2n+1/QBr half redox reactions in aqueous energy storage systems, such as Zn–Br redox flow batteries and Br-related redox enhanced electrochemical capacitors.
Yejin Choi; Cheonho Park; Yumin Kang; Jules Tshishimbi Muya; Dong Pyo Jang; Jinho Chang. Temporally Resolved Electrochemical Interrogation for Stochastic Collision Dynamics of Electrogenerated Single Polybromide Droplets. Analytical Chemistry 2021, 93, 8336 -8344.
AMA StyleYejin Choi, Cheonho Park, Yumin Kang, Jules Tshishimbi Muya, Dong Pyo Jang, Jinho Chang. Temporally Resolved Electrochemical Interrogation for Stochastic Collision Dynamics of Electrogenerated Single Polybromide Droplets. Analytical Chemistry. 2021; 93 (23):8336-8344.
Chicago/Turabian StyleYejin Choi; Cheonho Park; Yumin Kang; Jules Tshishimbi Muya; Dong Pyo Jang; Jinho Chang. 2021. "Temporally Resolved Electrochemical Interrogation for Stochastic Collision Dynamics of Electrogenerated Single Polybromide Droplets." Analytical Chemistry 93, no. 23: 8336-8344.
Dysregulation of the neurotransmitter dopamine (DA) is implicated in several neuropsychiatric conditions. Multiple-cyclic square-wave voltammetry (MCSWV) is a state-of-the-art technique for measuring tonic DA levels with high sensitivity (<5 nM), selectivity, and spatiotemporal resolution. Currently, however, analysis of MCSWV data requires manual, qualitative adjustments of analysis parameters, which can inadvertently introduce bias. Here, we demonstrate the development of a computational technique using a statistical model for standardized, unbiased analysis of experimental MCSWV data for unbiased quantification of tonic DA. The oxidation current in the MCSWV signal was predicted to follow a lognormal distribution. The DA-related oxidation signal was inferred to be present in the top 5% of this analytical distribution and was used to predict a tonic DA level. The performance of this technique was compared against the previously used peak-based method on paired in vivo and post-calibration in vitro datasets. Analytical inference of DA signals derived from the predicted statistical model enabled high-fidelity conversion of the in vivo current signal to a concentration value via in vitro post-calibration. As a result, this technique demonstrated reliable and improved estimation of tonic DA levels in vivo compared to the conventional manual post-processing technique using the peak current signals. These results show that probabilistic inference-based voltammetry signal processing techniques can standardize the determination of tonic DA concentrations, enabling progress toward the development of MCSWV as a robust research and clinical tool.
Jaekyung Kim; Abhijeet S. Barath; Aaron E. Rusheen; Juan M. Rojas Cabrera; J. Blair Price; Hojin Shin; Abhinav Goyal; Jason W. Yuen; Danielle E. Jondal; Charles D. Blaha; Kendall H. Lee; Dong Pyo Jang; Yoonbae Oh. Automatic and Reliable Quantification of Tonic Dopamine Concentrations In Vivo Using a Novel Probabilistic Inference Method. ACS Omega 2021, 6, 6607 -6613.
AMA StyleJaekyung Kim, Abhijeet S. Barath, Aaron E. Rusheen, Juan M. Rojas Cabrera, J. Blair Price, Hojin Shin, Abhinav Goyal, Jason W. Yuen, Danielle E. Jondal, Charles D. Blaha, Kendall H. Lee, Dong Pyo Jang, Yoonbae Oh. Automatic and Reliable Quantification of Tonic Dopamine Concentrations In Vivo Using a Novel Probabilistic Inference Method. ACS Omega. 2021; 6 (10):6607-6613.
Chicago/Turabian StyleJaekyung Kim; Abhijeet S. Barath; Aaron E. Rusheen; Juan M. Rojas Cabrera; J. Blair Price; Hojin Shin; Abhinav Goyal; Jason W. Yuen; Danielle E. Jondal; Charles D. Blaha; Kendall H. Lee; Dong Pyo Jang; Yoonbae Oh. 2021. "Automatic and Reliable Quantification of Tonic Dopamine Concentrations In Vivo Using a Novel Probabilistic Inference Method." ACS Omega 6, no. 10: 6607-6613.
Dysfunction in dopaminergic neuronal systems underlie a number of neurologic and psychiatric disorders such as Parkinson's disease, drug addiction, and schizophrenia. Dopamine systems communicate via two mechanisms, a fast “phasic” release (sub-second to second) that is related to salient stimuli and a slower “tonic” release (minutes to hours) that regulates receptor tone. Alterations in tonic levels are thought to be more critically important in enabling normal motor, cognitive, and motivational functions, and dysregulation in tonic dopamine levels are associated with neuropsychiatric disorders. Therefore, development of neurochemical recording techniques that enable rapid, selective, and quantitative measurements of changes in tonic extracellular levels are essential in determining the role of dopamine in both normal and disease states. Here, we review state-of-the-art advanced analytical techniques for in vivo detection of tonic levels, with special focus on electrochemical techniques for detection in humans.
Aaron E. Rusheen; Taylor A. Gee; Dong P. Jang; Charles D. Blaha; Kevin E. Bennet; Kendall H. Lee; Michael L. Heien; Yoonbae Oh. Evaluation of electrochemical methods for tonic dopamine detection in vivo. TrAC Trends in Analytical Chemistry 2020, 132, 116049 .
AMA StyleAaron E. Rusheen, Taylor A. Gee, Dong P. Jang, Charles D. Blaha, Kevin E. Bennet, Kendall H. Lee, Michael L. Heien, Yoonbae Oh. Evaluation of electrochemical methods for tonic dopamine detection in vivo. TrAC Trends in Analytical Chemistry. 2020; 132 ():116049.
Chicago/Turabian StyleAaron E. Rusheen; Taylor A. Gee; Dong P. Jang; Charles D. Blaha; Kevin E. Bennet; Kendall H. Lee; Michael L. Heien; Yoonbae Oh. 2020. "Evaluation of electrochemical methods for tonic dopamine detection in vivo." TrAC Trends in Analytical Chemistry 132, no. : 116049.
Although N-shaped fast scan cyclic voltammetry (N-FSCV) is well-established as an electroanalytical method to measure extracellular serotonin concentrations in vivo it is in need of improvement in both sensitivity and selectivity. Based on our previous studies using fast cyclic square-wave voltammetry (FCSWV) for in vivo dopamine measurements, we have modified this technique to optimize the detection of serotonin in vivo. A series of large amplitude square-shaped potentials was superimposed onto an N-shaped waveform to provide cycling through multiple redox reactions within the N-shaped waveform to increase sensitivity and selectivity to serotonin when combined with a two dimensional voltammogram. N-shaped fast cyclic square-wave voltammetry (N-FCSWV) showed significantly higher sensitivity to serotonin compared to conventional N-FSCV. In addition, N-FCSWV showed better performance than conventional N-shaped FSCV in differentiating serotonin from its major interferents, dopamine and 5-hydroxyindoleascetic acid (5-HIAA). It was also confirmed that the large amplitude of the square waveform did not influence local neuronal activity, and it could monitor electrical stimulation evoked phasic release of serotonin in the rat substantia nigra pars reticulata (SNr) before and after systemic injection of escitalopram (ESCIT, 10 mg/kg i.p.), a serotonin selective reuptake inhibitor.
Hojin Shin; Yoonbae Oh; Cheonho Park; Yu Min Kang; Hyun U. Cho; Charles D. Blaha; Kevin E. Bennet; Michael L. Heien; In Young Kim; Kendall H. Lee; Dong Pyo Jang. Sensitive and Selective Measurement of Serotonin in Vivo Using Fast Cyclic Square-Wave Voltammetry. Analytical Chemistry 2019, 92, 774 -781.
AMA StyleHojin Shin, Yoonbae Oh, Cheonho Park, Yu Min Kang, Hyun U. Cho, Charles D. Blaha, Kevin E. Bennet, Michael L. Heien, In Young Kim, Kendall H. Lee, Dong Pyo Jang. Sensitive and Selective Measurement of Serotonin in Vivo Using Fast Cyclic Square-Wave Voltammetry. Analytical Chemistry. 2019; 92 (1):774-781.
Chicago/Turabian StyleHojin Shin; Yoonbae Oh; Cheonho Park; Yu Min Kang; Hyun U. Cho; Charles D. Blaha; Kevin E. Bennet; Michael L. Heien; In Young Kim; Kendall H. Lee; Dong Pyo Jang. 2019. "Sensitive and Selective Measurement of Serotonin in Vivo Using Fast Cyclic Square-Wave Voltammetry." Analytical Chemistry 92, no. 1: 774-781.
The Papez circuit, including the fornix white matter bundle, is a well-known neural network that is involved in multiple limbic functions such as memory and emotional expression. We previously reported a large-animal study of deep brain stimulation (DBS) in the fornix that found stimulation-induced hemodynamic responses in both the medial limbic and corticolimbic circuits on functional resonance imaging (fMRI) and evoked dopamine responses in the nucleus accumbens (NAc), as measured by fast-scan cyclic voltammetry (FSCV). The effects of DBS on the fornix are challenging to analyze, given its structural complexity and connection to multiple neuronal networks. In this study, we extend our earlier work to a rodent model wherein we characterize regional brain activity changes resulting from fornix stimulation using fludeoxyglucose (18F-FDG) micro positron emission tomography (PET) and monitor neurochemical changes using FSCV with pharmacological confirmation. Both global functional changes and local changes were measured in a rodent model of fornix DBS. Functional brain activity was measured by micro-PET, and the neurochemical changes in local areas were monitored by FSCV. Micro-PET images revealed increased glucose metabolism within the medial limbic and corticolimbic circuits. Neurotransmitter efflux induced by fornix DBS was monitored at NAc by FSCV and identified by specific neurotransmitter reuptake inhibitors. We found a significant increase in the metabolic activity in several key regions of the medial limbic circuits and dopamine efflux in the NAc following fornix stimulation. These results suggest that electrical stimulation of the fornix modulates the activity of brain memory circuits, including the hippocampus and NAc within the dopaminergic pathway.
Hojin Shin; Sang-Yoon Lee; Hyun-U Cho; Yoonbae Oh; In Young Kim; Kendall H. Lee; Dong Pyo Jang; Hoon-Ki Min. Fornix Stimulation Induces Metabolic Activity and Dopaminergic Response in the Nucleus Accumbens. Frontiers in Neuroscience 2019, 13, 1109 .
AMA StyleHojin Shin, Sang-Yoon Lee, Hyun-U Cho, Yoonbae Oh, In Young Kim, Kendall H. Lee, Dong Pyo Jang, Hoon-Ki Min. Fornix Stimulation Induces Metabolic Activity and Dopaminergic Response in the Nucleus Accumbens. Frontiers in Neuroscience. 2019; 13 ():1109.
Chicago/Turabian StyleHojin Shin; Sang-Yoon Lee; Hyun-U Cho; Yoonbae Oh; In Young Kim; Kendall H. Lee; Dong Pyo Jang; Hoon-Ki Min. 2019. "Fornix Stimulation Induces Metabolic Activity and Dopaminergic Response in the Nucleus Accumbens." Frontiers in Neuroscience 13, no. : 1109.
A number of previous studies revealed the importance of the frontoparietal network for attention and preparatory top‐down control. Here, we investigated the theta (7–9 Hz) coherence of the right frontoparietal networks to explore the differences in connectivity changes for the right frontoparietal regions during spatial attention (i.e., attention to a specific location rather than a specific feature) and nonspatial attention (i.e., attention to a specific feature rather than a specific location) tasks. The theta coherence in both tasks was primarily maintained at a preparatory state, decreases after stimulus onset, and recovers to the level of the preparatory state after the response time. However, the theta coherence of the frontoparietal network during spatial attention was immediately maintained after cue‐onset, whereas for the case of nonspatial attention, it was immediately decreased after cue‐onset. In addition, the connectivity of the right frontoparietal network, including the middle frontal gyrus and superior parietal lobe, were significantly higher for spatial attention rather than for nonspatial attention, suggesting that the dorsal parts of right frontoparietal network are more engaged in spatial‐specific attention from the preparatory state. These findings also suggest that these two attention systems involve the use of different regional connectivity patterns, not only in the cognitive state, but in the preparatory state as well.
Young Min Park; Jinsick Park; Joon Hyun Baek; Sun I. Kim; In Young Kim; Joong Koo Kang; Dong Pyo Jang. Differences in theta coherence between spatial and nonspatial attention using intracranial electroencephalographic signals in humans. Human Brain Mapping 2019, 40, 2336 -2346.
AMA StyleYoung Min Park, Jinsick Park, Joon Hyun Baek, Sun I. Kim, In Young Kim, Joong Koo Kang, Dong Pyo Jang. Differences in theta coherence between spatial and nonspatial attention using intracranial electroencephalographic signals in humans. Human Brain Mapping. 2019; 40 (8):2336-2346.
Chicago/Turabian StyleYoung Min Park; Jinsick Park; Joon Hyun Baek; Sun I. Kim; In Young Kim; Joong Koo Kang; Dong Pyo Jang. 2019. "Differences in theta coherence between spatial and nonspatial attention using intracranial electroencephalographic signals in humans." Human Brain Mapping 40, no. 8: 2336-2346.
Classification of spoken word-evoked potentials is useful for both neuroscientific and clinical applications including brain-computer interfaces (BCIs). By evaluating whether adopting a biology-based structure improves a classifier’s accuracy, we can investigate the importance of such structure in human brain circuitry, and advance BCI performance. In this study, we propose a semantic-hierarchical structure for classifying spoken word-evoked cortical responses. The proposed structure decodes the semantic grouping of the words first (e.g., a body part vs. a number) and then decodes which exact word was heard. The proposed classifier structure exhibited a consistent ~10% improvement of classification accuracy when compared with a non-hierarchical structure. Our result provides a tool for investigating the neural representation of semantic hierarchy and the acoustic properties of spoken words in human brains. Our results suggest an improved algorithm for BCIs operated by decoding heard, and possibly imagined, words.
Youngmin Na; Inyong Choi; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. Semantic-hierarchical model improves classification of spoken-word evoked electrocorticography. Journal of Neuroscience Methods 2018, 311, 253 -258.
AMA StyleYoungmin Na, Inyong Choi, Dong Pyo Jang, Joong Koo Kang, Jihwan Woo. Semantic-hierarchical model improves classification of spoken-word evoked electrocorticography. Journal of Neuroscience Methods. 2018; 311 ():253-258.
Chicago/Turabian StyleYoungmin Na; Inyong Choi; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. 2018. "Semantic-hierarchical model improves classification of spoken-word evoked electrocorticography." Journal of Neuroscience Methods 311, no. : 253-258.
Although fast-scan cyclic voltammetry (FSCV) has been widely used for in vivo neurochemical detection, the sensitivity and selectivity of the technique can be further improved. In this study, we develop fast cyclic square-wave voltammetry (FCSWV) as a novel voltammetric technique that combines large amplitude cyclic square-wave voltammetry (CSWV) with background subtraction. A large-amplitude, square-shaped potential was applied to induce cycling through multiple redox reactions within a square pulse to increase sensitivity and selectivity when combined with a 2D voltammogram. As a result, FCSWV was significantly more sensitive than FSCV (n=5 electrodes, two-way ANOVA, p=0.0002). In addition, FCSWV could differentiate dopamine from other catecholamines (e.g., epinephrine and norepinephrine) and serotonin better than conventional FSCV. With the confirmation that FCSWV did not influence local neuronal activity, despite the large amplitude of the square waveform, it could monitor electrically induced phasic changes in dopamine release in rat striatum before and after injecting nomifensine, a dopamine reuptake inhibitor.
Cheonho Park; Yoonbae Oh; Hojin Shin; Jaekyung Kim; Yu Min Kang; Jeongeun Sim; Hyun U. Cho; Hankyu Lee; Sung Jun Jung; Charles D. Blaha; Kevin E. Bennet; Michael L. Heien; Kendall H. Lee; In Young Kim; Dong Pyo Jang. Fast Cyclic Square-Wave Voltammetry To Enhance Neurotransmitter Selectivity and Sensitivity. Analytical Chemistry 2018, 90, 13348 -13355.
AMA StyleCheonho Park, Yoonbae Oh, Hojin Shin, Jaekyung Kim, Yu Min Kang, Jeongeun Sim, Hyun U. Cho, Hankyu Lee, Sung Jun Jung, Charles D. Blaha, Kevin E. Bennet, Michael L. Heien, Kendall H. Lee, In Young Kim, Dong Pyo Jang. Fast Cyclic Square-Wave Voltammetry To Enhance Neurotransmitter Selectivity and Sensitivity. Analytical Chemistry. 2018; 90 (22):13348-13355.
Chicago/Turabian StyleCheonho Park; Yoonbae Oh; Hojin Shin; Jaekyung Kim; Yu Min Kang; Jeongeun Sim; Hyun U. Cho; Hankyu Lee; Sung Jun Jung; Charles D. Blaha; Kevin E. Bennet; Michael L. Heien; Kendall H. Lee; In Young Kim; Dong Pyo Jang. 2018. "Fast Cyclic Square-Wave Voltammetry To Enhance Neurotransmitter Selectivity and Sensitivity." Analytical Chemistry 90, no. 22: 13348-13355.
A fronto-parietal network, comprised of the posterior parietal cortex (PPC) and the dorsal premotor cortex (PMd) has been proposed to be involved in planning and guiding movement. However, the issue of how the network is expressed across the bilateral cortical area according to the effector's side remains unclear. In this study, we tested these questions using electrocorticographic (ECoG) recordings in non-human primates and using a simple visual guided reaching task that induced a left or right hand response based on relevant cues provided for the task. The findings indicate that right hemisphere lateralized network patterns in which the right PMd was strongly coordinated with bilateral PPC immediately after presentation of the movement cue occurred, while the coherence with the left PMd was not enhanced. No difference was found in the coherence pattern between the effector's side (left hand or right hand), but the strength of coherence was different, in that animals showed a higher coherence in the right hand response compared to the left. Our data support that right lateralization in long-range phase synchrony in the 10–20 Hz low beta band is involved in motor preparation stage, irrespective of the upcoming effector's side.
Jeyeon Lee; Hoseok Choi; Kyeongran Min; Seho Lee; Kyung-Ha Ahn; Hang Joon Jo; In Young Kim; Dong Pyo Jang; Kyoung-Min Lee. Right Hemisphere Lateralization in Neural Connectivity Within Fronto-Parietal Networks in Non-human Primates During a Visual Reaching Task. Frontiers in Behavioral Neuroscience 2018, 12, 1 .
AMA StyleJeyeon Lee, Hoseok Choi, Kyeongran Min, Seho Lee, Kyung-Ha Ahn, Hang Joon Jo, In Young Kim, Dong Pyo Jang, Kyoung-Min Lee. Right Hemisphere Lateralization in Neural Connectivity Within Fronto-Parietal Networks in Non-human Primates During a Visual Reaching Task. Frontiers in Behavioral Neuroscience. 2018; 12 ():1.
Chicago/Turabian StyleJeyeon Lee; Hoseok Choi; Kyeongran Min; Seho Lee; Kyung-Ha Ahn; Hang Joon Jo; In Young Kim; Dong Pyo Jang; Kyoung-Min Lee. 2018. "Right Hemisphere Lateralization in Neural Connectivity Within Fronto-Parietal Networks in Non-human Primates During a Visual Reaching Task." Frontiers in Behavioral Neuroscience 12, no. : 1.
The suggested electrode can offer whole-brain monitoring with high signal quality and minimal invasiveness. The screw ECoG can be used to provide more in-depth understanding, not only relationship between functional networks and cognitive behavior, but also pathomechanisms in brain diseases.
Hoseok Choi; Seho Lee; Jeyeon Lee; Kyeongran Min; Seokbeen Lim; Jinsick Park; Kyoung-Ha Ahn; In Young Kim; Kyoung-Min Lee; Dong Pyo Jang. Long-term evaluation and feasibility study of the insulated screw electrode for ECoG recording. Journal of Neuroscience Methods 2018, 308, 261 -268.
AMA StyleHoseok Choi, Seho Lee, Jeyeon Lee, Kyeongran Min, Seokbeen Lim, Jinsick Park, Kyoung-Ha Ahn, In Young Kim, Kyoung-Min Lee, Dong Pyo Jang. Long-term evaluation and feasibility study of the insulated screw electrode for ECoG recording. Journal of Neuroscience Methods. 2018; 308 ():261-268.
Chicago/Turabian StyleHoseok Choi; Seho Lee; Jeyeon Lee; Kyeongran Min; Seokbeen Lim; Jinsick Park; Kyoung-Ha Ahn; In Young Kim; Kyoung-Min Lee; Dong Pyo Jang. 2018. "Long-term evaluation and feasibility study of the insulated screw electrode for ECoG recording." Journal of Neuroscience Methods 308, no. : 261-268.
For over two decades, fast-scan cyclic voltammetry (FSCV) has served as a reliable analytical method for monitoring dopamine release in near real-time in vivo. However, contemporary FSCV techniques have been limited to measure only rapid (on the order of seconds, i.e. phasic) changes in dopamine release evoked by either electrical stimulation or elicited by presentation of behaviorally salient stimuli, and not slower changes in the tonic extracellular levels of dopamine (i.e. basal concentrations). This is because FSCV is inherently a differential method that requires subtraction of prestimulation tonic levels of dopamine to measure phasic changes relative to a zeroed baseline. Here, we describe the development and application of a novel voltammetric technique, multiple cyclic square wave voltammetry (M-CSWV), for analytical quantification of tonic dopamine concentrations in vivo with relatively high temporal resolution (10 s). M-CSWV enriches the electrochemical information by generating two dimensional voltammograms which enable high sensitivity (limit of detection, 0.17 nM) and selectivity against ascorbic acid, and 3,4-dihydroxyphenylacetic acid (DOPAC), including changes in pH. Using M-CSWV, a tonic dopamine concentration of 120 ± 18 nM (n = 7 rats, ± SEM) was determined in the striatum of urethane anethetized rats. Pharmacological treatments to elevate dopamine by selectively inhibiting dopamine reuptake and to reduce DOPAC by inhibition of monoamine oxidase supported the selective detection of dopamine in vivo. Overall, M-CSWV offers a novel voltammetric technique to quantify levels and monitor changes in tonic dopamine concentrations in the brain to further our understanding of the role of dopamine in normal behavior and neuropsychiatric disorders.
Yoonbae Oh; Michael L. Heien; Cheonho Park; Yu Min Kang; Jaekyung Kim; Suelen Lucio Boschen; Hojin Shin; Hyun U. Cho; Charles D. Blaha; Kevin E. Bennet; Hankyu Lee; Sung Jun Jung; In Young Kim; Kendall H. Lee; Dong Pyo Jang. Tracking tonic dopamine levels in vivo using multiple cyclic square wave voltammetry. Biosensors and Bioelectronics 2018, 121, 174 -182.
AMA StyleYoonbae Oh, Michael L. Heien, Cheonho Park, Yu Min Kang, Jaekyung Kim, Suelen Lucio Boschen, Hojin Shin, Hyun U. Cho, Charles D. Blaha, Kevin E. Bennet, Hankyu Lee, Sung Jun Jung, In Young Kim, Kendall H. Lee, Dong Pyo Jang. Tracking tonic dopamine levels in vivo using multiple cyclic square wave voltammetry. Biosensors and Bioelectronics. 2018; 121 ():174-182.
Chicago/Turabian StyleYoonbae Oh; Michael L. Heien; Cheonho Park; Yu Min Kang; Jaekyung Kim; Suelen Lucio Boschen; Hojin Shin; Hyun U. Cho; Charles D. Blaha; Kevin E. Bennet; Hankyu Lee; Sung Jun Jung; In Young Kim; Kendall H. Lee; Dong Pyo Jang. 2018. "Tracking tonic dopamine levels in vivo using multiple cyclic square wave voltammetry." Biosensors and Bioelectronics 121, no. : 174-182.
Joo Young Kim; Kyoung Won Nam; Jun Chang Lee; Jong Ho Hwang; Dong Pyo Jang; In Young Kim. Scalp tapping-based protocol for adjusting the parameters of binaural hearing aids. Biomedical Signal Processing and Control 2018, 45, 91 -97.
AMA StyleJoo Young Kim, Kyoung Won Nam, Jun Chang Lee, Jong Ho Hwang, Dong Pyo Jang, In Young Kim. Scalp tapping-based protocol for adjusting the parameters of binaural hearing aids. Biomedical Signal Processing and Control. 2018; 45 ():91-97.
Chicago/Turabian StyleJoo Young Kim; Kyoung Won Nam; Jun Chang Lee; Jong Ho Hwang; Dong Pyo Jang; In Young Kim. 2018. "Scalp tapping-based protocol for adjusting the parameters of binaural hearing aids." Biomedical Signal Processing and Control 45, no. : 91-97.
A novel multi-waveform FSCV (M-FSCV) developed for characterizing adsorption/desorption kinetics of neurotransmitters.
Do Hyoung Kim; Yoonbae Oh; Hojin Shin; Cheonho Park; Charles D. Blaha; Kevin E. Bennet; In Young Kim; Kendall H. Lee; Dong Pyo Jang. Multi-waveform fast-scan cyclic voltammetry mapping of adsorption/desorption kinetics of biogenic amines and their metabolites. Analytical Methods 2018, 10, 2834 -2843.
AMA StyleDo Hyoung Kim, Yoonbae Oh, Hojin Shin, Cheonho Park, Charles D. Blaha, Kevin E. Bennet, In Young Kim, Kendall H. Lee, Dong Pyo Jang. Multi-waveform fast-scan cyclic voltammetry mapping of adsorption/desorption kinetics of biogenic amines and their metabolites. Analytical Methods. 2018; 10 (24):2834-2843.
Chicago/Turabian StyleDo Hyoung Kim; Yoonbae Oh; Hojin Shin; Cheonho Park; Charles D. Blaha; Kevin E. Bennet; In Young Kim; Kendall H. Lee; Dong Pyo Jang. 2018. "Multi-waveform fast-scan cyclic voltammetry mapping of adsorption/desorption kinetics of biogenic amines and their metabolites." Analytical Methods 10, no. 24: 2834-2843.
In this study, to measure blood pressure (BP) on the basis of human hearing threshold, we proposed a method that detects the audible or inaudible Korotkoff sounds (K-sounds) using the equal loudness contour and automatically assesses the BP. In this study, we detected the systolic period of K-sounds using cuff pressure oscillation and then converted the K-sounds corresponding to the systolic interval into sound pressure levels (SPLs). Next, the systolic blood pressure (SBP) and diastolic blood pressure (DBP) were assessed by mapping the K-sounds, which were converted into SPLs on an equal loudness contour. To validate the accuracy of our proposed method, we compared it with the auscultatory method. The mean differences (mean±SD) in the SBP and DBP were 0.31±1.95 and 1.20±2.17 mmHg, respectively. For the SBP, the linear regression equation was y=0.98x+1.56 mmHg (where x and y represent the auscultatory and the proposed method, respectively), with a SE of estimate of 1.93 mmHg and a correlation coefficient of 0.99. For the DBP, the linear regression equation was y=1.01x−1.94 mmHg, with an SE of estimate of 2.18 mmHg and a correlation coefficient of 0.98. All P values were less than 0.0001 for both regressions. The auscultatory method of BP monitoring is sensitive to the observer’s condition or environmental noise. To overcome these disadvantages, we used the human hearing threshold for objective SBP and DBP automatic assessment, and this method can be applicable to an automatic auscultatory method.
Sung Jun Hong; Jong Shill Lee; Jae Hoon Oh; Young Joon Chee; Dong Pyo Jang; In Young Kim. Automatic assessment of blood pressure for Korotkoff sounds on the basis of human hearing threshold. Blood Pressure Monitoring 2017, 22, 364 -370.
AMA StyleSung Jun Hong, Jong Shill Lee, Jae Hoon Oh, Young Joon Chee, Dong Pyo Jang, In Young Kim. Automatic assessment of blood pressure for Korotkoff sounds on the basis of human hearing threshold. Blood Pressure Monitoring. 2017; 22 (6):364-370.
Chicago/Turabian StyleSung Jun Hong; Jong Shill Lee; Jae Hoon Oh; Young Joon Chee; Dong Pyo Jang; In Young Kim. 2017. "Automatic assessment of blood pressure for Korotkoff sounds on the basis of human hearing threshold." Blood Pressure Monitoring 22, no. 6: 364-370.
A simple, and yet robust, high pass filter is designed to remove non-linear background drift in fast scan cyclic voltammetry.
Mark DeWaele; Yoonbae Oh; Cheonho Park; Yu Min Kang; Hojin Shin; Charles D. Blaha; Kevin E. Bennet; In Young Kim; Kendall H. Lee; Dong Pyo Jang. A baseline drift detrending technique for fast scan cyclic voltammetry. The Analyst 2017, 142, 4317 -4321.
AMA StyleMark DeWaele, Yoonbae Oh, Cheonho Park, Yu Min Kang, Hojin Shin, Charles D. Blaha, Kevin E. Bennet, In Young Kim, Kendall H. Lee, Dong Pyo Jang. A baseline drift detrending technique for fast scan cyclic voltammetry. The Analyst. 2017; 142 (22):4317-4321.
Chicago/Turabian StyleMark DeWaele; Yoonbae Oh; Cheonho Park; Yu Min Kang; Hojin Shin; Charles D. Blaha; Kevin E. Bennet; In Young Kim; Kendall H. Lee; Dong Pyo Jang. 2017. "A baseline drift detrending technique for fast scan cyclic voltammetry." The Analyst 142, no. 22: 4317-4321.
In this study, we investigated where the sex differences of object-location binding memory performance were influenced by the cognitive load. We used the fractal objects version of the ‘What was where?’ task to measure object memory, location memory and objection-location binding memory. Cognitive load was controlled by task difficulty presented two sessions: one session randomly displayed three or four fractal objects (Session 34) and the other session four or five objects (Session 45). The results showed that females outperformed males on object-location binding memory. Interestingly, even when the four object trials were compared between Session 34 and Session 45, in which we believed that the level of difficulty was similar while cognitive load varied, the swap error of males was significantly increased in Session 45 compared to females. In conclusion, there may be sex differences in object-location binding memory and the males could be more sensitive about the cognitive load than females.
Jinsick Park; Ga In Shin; Young Min Park; In Young Kim; Dong Pyo Jang. Sex differences of cognitive load effects on object-location binding memory. Biomedical Engineering Letters 2017, 7, 305 -309.
AMA StyleJinsick Park, Ga In Shin, Young Min Park, In Young Kim, Dong Pyo Jang. Sex differences of cognitive load effects on object-location binding memory. Biomedical Engineering Letters. 2017; 7 (4):305-309.
Chicago/Turabian StyleJinsick Park; Ga In Shin; Young Min Park; In Young Kim; Dong Pyo Jang. 2017. "Sex differences of cognitive load effects on object-location binding memory." Biomedical Engineering Letters 7, no. 4: 305-309.
Generalized tonic-clonic seizures (GTCSs) can be underestimated and can also increase mortality rates. The monitoring devices used to detect GTCS events in daily life are very helpful for early intervention and precise estimation of seizure events. Several studies have introduced methods for GTCS detection using an accelerometer (ACM), electromyography, or electroencephalography. However, these studies need to be improved with respect to accuracy and user convenience. This study proposes the use of an ACM banded to the wrist and spectral analysis of ACM data to detect GTCS in daily life. The spectral weight function dependent on GTCS was used to compute a GTCS-correlated score that can effectively discriminate between GTCS and normal movement. Compared to the performance of the previous temporal method, which used a standard deviation method, the spectral analysis method resulted in better sensitivity and fewer false positive alerts. Finally, the spectral analysis method can be implemented in a GTCS monitoring device using an ACM and can provide early alerts to caregivers to prevent risks associated with GTCS.
Hyo Sung Joo; Su-Hyun Han; Jongshill Lee; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. Spectral Analysis of Acceleration Data for Detection of Generalized Tonic-Clonic Seizures. Sensors 2017, 17, 481 .
AMA StyleHyo Sung Joo, Su-Hyun Han, Jongshill Lee, Dong Pyo Jang, Joong Koo Kang, Jihwan Woo. Spectral Analysis of Acceleration Data for Detection of Generalized Tonic-Clonic Seizures. Sensors. 2017; 17 (3):481.
Chicago/Turabian StyleHyo Sung Joo; Su-Hyun Han; Jongshill Lee; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. 2017. "Spectral Analysis of Acceleration Data for Detection of Generalized Tonic-Clonic Seizures." Sensors 17, no. 3: 481.
In arm movement BCI (brain-computer interface), the unimanual research has been well. However, the bimanual brain state is known to be different from the unimanual one, so the conventional arm movement decoding method seems to be insufficient to decode bimanual movement. In this research, we suggested the hybrid method to improve the decoding accuracy for bimanual movement estimation. The method consists of two step; 1st step: the movement conditions classification, and 2nd step: the hand trajectory prediction algorithm. As a result, the hybrid method showed improved arm movement decoding performance and significant and stable decoding rate over several months for bimanual tasks. This technique could be applied to arm movement BCI in real world and the various neuro-prosthetics fields.
Hoseok Choi; Dong Pyo Jang; Kyoung-Min Lee. Bimanual Arm Movements Decoding using Hybrid Method. 2017 5th International Winter Conference on Brain-Computer Interface (BCI) 2017, 60 -62.
AMA StyleHoseok Choi, Dong Pyo Jang, Kyoung-Min Lee. Bimanual Arm Movements Decoding using Hybrid Method. 2017 5th International Winter Conference on Brain-Computer Interface (BCI). 2017; ():60-62.
Chicago/Turabian StyleHoseok Choi; Dong Pyo Jang; Kyoung-Min Lee. 2017. "Bimanual Arm Movements Decoding using Hybrid Method." 2017 5th International Winter Conference on Brain-Computer Interface (BCI) , no. : 60-62.
A brain-computer interface (BCI) can be used to restore some communication as an alternative interface for patients suffering from locked-in syndrome. However, most BCI systems are based on SSVEP, P300, or motor imagery, and a diversity of BCI protocols would be needed for various types of patients. In this paper, we trained the choice saccade (CS) task in 2 non-human primate monkeys and recorded the brain signal using an epidural electrocorticogram (eECoG) to predict eye movement direction. We successfully predicted the direction of the upcoming eye movement using a support vector machine (SVM) with the brain signals after the directional cue onset and before the saccade execution. The mean accuracies were 80% for 2 directions and 43% for 4 directions. We also quantified the spatial-spectro-temporal contribution ratio using SVM recursive feature elimination (RFE). The channels over the frontal eye field (FEF), supplementary eye field (SEF), and superior parietal lobule (SPL) area were dominantly used for classification. The α-band in the spectral domain and the time bins just after the directional cue onset and just before the saccadic execution were mainly useful for prediction. A saccade based BCI paradigm can be projected in the 2D space, and will hopefully provide an intuitive and convenient communication platform for users.
Jeyeon Lee; Hoseok Choi; Seho Lee; Baek Hwan Cho; Kyoung-Ha Ahn; In Young Kim; Kyoung-Min Lee; Dong-Pyo Jang. Decoding Saccadic Directions Using Epidural ECoG in Non-Human Primates. Journal of Korean Medical Science 2017, 32, 1243 -1250.
AMA StyleJeyeon Lee, Hoseok Choi, Seho Lee, Baek Hwan Cho, Kyoung-Ha Ahn, In Young Kim, Kyoung-Min Lee, Dong-Pyo Jang. Decoding Saccadic Directions Using Epidural ECoG in Non-Human Primates. Journal of Korean Medical Science. 2017; 32 (8):1243-1250.
Chicago/Turabian StyleJeyeon Lee; Hoseok Choi; Seho Lee; Baek Hwan Cho; Kyoung-Ha Ahn; In Young Kim; Kyoung-Min Lee; Dong-Pyo Jang. 2017. "Decoding Saccadic Directions Using Epidural ECoG in Non-Human Primates." Journal of Korean Medical Science 32, no. 8: 1243-1250.
The generation of pain signals from primary afferent neurons is explained by a labeled-line code. However, this notion cannot apply in a simple way to cutaneous C-fibers, which carry signals from a variety of receptors that respond to various stimuli including agonist chemicals. To represent the discharge patterns of C-fibers according to different agonist chemicals, we have developed a quantitative approach using three consecutive spikes. By using this method, the generation of pain in response to chemical stimuli is shown to be dependent on the temporal aspect of the spike trains. Furthermore, under pathological conditions, gamma-aminobutyric acid resulted in pain behavior without change of spike number but with an altered discharge pattern. Our results suggest that information about the agonist chemicals may be encoded in specific temporal patterns of signals in C-fibers, and nociceptive sensation may be influenced by the extent of temporal summation originating from the temporal patterns.
Kyeongwon Cho; Jun Ho Jang; Sung-Phil Kim; Sang Hoon Lee; Soon-Cheol Chung; In Young Kim; Dong Pyo Jang; Sung Jun Jung. Analysis of Nociceptive Information Encoded in the Temporal Discharge Patterns of Cutaneous C-Fibers. Frontiers in Computational Neuroscience 2016, 10, 1 .
AMA StyleKyeongwon Cho, Jun Ho Jang, Sung-Phil Kim, Sang Hoon Lee, Soon-Cheol Chung, In Young Kim, Dong Pyo Jang, Sung Jun Jung. Analysis of Nociceptive Information Encoded in the Temporal Discharge Patterns of Cutaneous C-Fibers. Frontiers in Computational Neuroscience. 2016; 10 ():1.
Chicago/Turabian StyleKyeongwon Cho; Jun Ho Jang; Sung-Phil Kim; Sang Hoon Lee; Soon-Cheol Chung; In Young Kim; Dong Pyo Jang; Sung Jun Jung. 2016. "Analysis of Nociceptive Information Encoded in the Temporal Discharge Patterns of Cutaneous C-Fibers." Frontiers in Computational Neuroscience 10, no. : 1.