Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Iramina Keiji Last modified date:2024.06.03

Professor / Intelligent Science / Department of Informatics / Faculty of Information Science and Electrical Engineering


Papers
1. Sho Ageno, Keiji Iramina, Analysis of Time-varying Brain Network Activity Using Functional Connectivity and Graph Theory during Memory Retrieval, Advanced Biomedical Engineering, https://doi.org/10.14326/abe.13.123, 11, 123-133, 2024.03, n many memory impairment cases, memory failure is due to impaired retrieval and not loss of memory information. Studies on memory retrieval using electroencephalography have mainly focused on changes in power and connectivity in the gamma band, which is a high-frequency region (> 30 Hz). However, previous research has not focused in detail on network activity during memory retrieval. To clarify this, we quantitatively compared retrieval and non-retrieval conditions using network analysis for time-varying functional connectivity. This study analyzed memory retrieval using a paired associative learning task. Consequently, this research found gamma band responses similar to those observed in previous time-frequency analysis in high gamma band. Furthermore, the high-gamma characteristic path length in the target condition was significantly higher than that in the distractor condition. The network becomes more efficient in the non-retrieval condition in the high-gamma band (50-80 Hz). We considered that this was due to the high workload, resulting in distracted memory retrieval. In non-retrieval conditions, participants must focus only on the next stimuli, which may increase network efficiency. We believe that this study shows the potential of a time-varying network analysis for revealing complex brain network activity..
2. Watchara Sroykham, Keiji Iramina, Thanate Angsuwatanakul, Yodchanan Wongsawat, Investigating the Effects of Color Light on Brain Activity Using NIRS: Implications for Emotion Regulation and Cognitive Function, 2023 15th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON60347.2023.10321984, 2023.11.
3. Yueling Zhang, Keiji Iramina, Linear Relationship between Corticomusclar Coherence and Upper Limb Voluntary Contraction, 2023 15th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON60347.2023.10322082, 2023.11.
4. Nyi Nyi Tun, Fumiya Sanuki, Keiji Iramina, Brain-muscle Interaction Analysis with Time-variant Granger Causality, 2023 IEEE 19th International Conference on Body Sensor Networks (BSN), 10.1109/BSN58485.2023.10330913, 2023.10.
5. Wenli Lan, Ruimin Wang, Yikang He, Yuan Zong, Yue Leng, Keiji Iramina, Wenming Zheng, Sheng Ge, Cross Domain Correlation Maximization for Enhancing the Target Recognition of SSVEP-Based Brain–Computer Interfaces, IEEE Transactions on Neural Systems and Rehabilitation Engineering , 10.1109/TNSRE.2023.3309543, 31, 3545-3555, 2023.08.
6. Sheng Ge, Hui Yang, Ruimin Wang, Yue Leng, Keiji Iramina, Pan Lin, Haixian Wang, Block Distributed Joint Temporal-Frequency- Phase Modulation for Steady-State Visual Evoked Potential Based Brain-Computer Interface With a Limited Number of Frequencies, IEEE Journal of Biomedical and Health Informatics, 10.1109/JBHI.2023.3244277, 27, 4, 1835-1844, 2023.04.
7. Sheng Ge; Jing He; Pan Lin; Ruimin Wang; Keiji Iramina; Yue Leng; Haixian Wang; Wenming Zheng; Chaoyong Xiao, Effective Connectivity Analysis and Classification of Action Observation From Different Perspectives: An fMRI Study, IEEE Transactions on Biomedical Engineering, 10.1109/TBME.2022.3201547, 70, 2, 723-734, 2023.02.
8. Nina Itagaki, Yutaro Nakada, Keiji Iramina, The effect of visual cognition on the fear caused by pain recall, 2022 14th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON56653.2022.10012108, 2022.11, In this study, we investigated whether working memory training affects on the improvement of basic skills in Mathematics and English among high school students. Forty-two high school students were divided into two groups, one with and one without working memory training. The training group received about 10 minutes of dual N-back task training per day for 10 days, excluding Saturdays and Sundays. To evaluate the effects of working memory training, three assessment tasks were used: mental arithmetic, writing English sentences, and backward digit reciting. The results showed that there was no significant difference in the effectiveness of training between the training and control groups. However, there was a little tendency of the effects of the training when it came to memorizing multiplication and reciting many numbers in reverse, which consume a large amount of working memory capacity.These results seemed to be thought to be due to the short training program period and short time of training in each session..
9. Fumiya Sanuki, Nonthaporn Nakphu, Ayumi Tahara, Keiji Iramina, The comparison of electroencephalography power and event related potential in success and failure during multitask game, Frontiers in Neurorobotics, 10.3389/fnbot.2022.1044071, 16, 16:1044071, 1044071, 2022.11.
10. He Qiao, Ayumi Tahara, Nonthaporn NakphuKeiji Iramina, Using Mean Pupil Diameter Change to Analyze Behavioral Performance in Multitasking Training Game, 2022 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 10.1109/EMBC48229.2022.9871751, 2022.09.
11. Sho Ageno, Shu Tanaka, Ryoya Okura, Keiji Iramina, Differences in EEG-based Brain Network Activity during Non-REM Sleep, Advanced Biomedical Engineering, https://doi.org/10.14326/abe.11.109, 11, 109-116, 2022.03, Numerous studies have suggested that sleep spindle waves may play a role in the hippocampal-cortical transmission of information associated with memory enhancement. In previous research, the clustering coefficient increased significantly from wakefulness to sleep, indicating that the graph theory may be able to characterize brain network activity during sleep. However, previous studies have not investigated in detail the characteristics of the brain network in individual sleep stages; the brain network activity in the EEG at each sleep stage has not yet been clarified. In this study, we compared the characteristics of the network activity in various sleep stages by determining the functional connectivity from EEG in individual stages, constructing the networks and comparing the clustering coefficients and characteristic path lengths. We found a significant decrease in the characteristic path length in LowBeta band (13–15 Hz) from Stage 1 to later stages. However, there was no significant difference in the clustering coefficient. Our results are consistent with the concept that sleep spindles are related to memory consolidation. Therefore, the results suggest that the networks generated by the brain are more efficient in middle and deep sleep..
12. Misato Oka, Junna Muta, Kiko Sato, Eiji Ikuta, Keiji Iramina, Effect of Working Memory Training on Learning Ability of High School Students, 2021 13th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON53485.2021.9745247, 2021.11, In this study, we investigated whether working memory training affects on the improvement of basic skills in Mathematics and English among high school students. Forty-two high school students were divided into two groups, one with and one without working memory training. The training group received about 10 minutes of dual N-back task training per day for 10 days, excluding Saturdays and Sundays. To evaluate the effects of working memory training, three assessment tasks were used: mental arithmetic, writing English sentences, and backward digit reciting. The results showed that there was no significant difference in the effectiveness of training between the training and control groups. However, there was a little tendency of the effects of the training when it came to memorizing multiplication and reciting many numbers in reverse, which consume a large amount of working memory capacity.These results seemed to be thought to be due to the short training program period and short time of training in each session..
13. Fumiya Sanuki, Nonthaporn Nakphu, Ayumi Tahara, Shodai Suehiro,Haruki Nishimura, Keiji Iramina, Comparison of brain activity in success and failure in single and multitask game, 2021 13th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON53485.2021.9745233, 2021.11.
14. Hadriana Iddas, Harlinda Lahuddin, Syamsul Bahri, Keiji Iramina, Identifying Audio-Visual Familiarity Effects on Emotion via Directed Functional Connectivity, 2021 6th International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS), 10.1109/ICIIBMS52876.2021.9651562, 2021.11.
15. Nyi Nyi Tun, Sanuki Fumiya, Keiji Iramina, EEG-EMG Correlation Analysis with Linear and Nonlinear Coupling Methods Across Four Motor Tasks, 2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 10.1109/EMBC46164.2021.9629969, 783-786, 2021.11.
16. Wenli Lan, Hui Yang, Jing He, Yue Leng, Ruimin Wang, Keiji Iramina, Sheng Ge, Effect of Channel and Reference Selection on a Non-occipital Steady-State Visual Evoked Potential-Based Brain-Computer Interface, 2021 IEEE 5th Information Technology,Networking,Electronic and Automation Control Conference (ITNEC), 10.1109/ITNEC52019.2021.9586876, 2021.10.
17. Jing He, Wenli Lan, Hui Yang, Pan Lin, Yue Leng, Ruimin Wang, Keiji Iramina, Sheng Ge, Investigating Effective Brain Networks of Action Observation Tasks from Different Visual Perspectives based on Generalized Partial Directed Coherence: An fMRI Study, 2021 IEEE 5th Information Technology,Networking,Electronic and Automation Control Conference (ITNEC), 10.1109/ITNEC52019.2021.9587117, 2021.10.
18. Hui Yang, Wenli Lan, Jing He, Yue Leng, Ruimin Wang, Keiji Iramina, Sheng Ge, Modular Time-Frequency Joint Coding for a Virtual Keyboard Speller Using an SSVEP-Based Brain-Computer Interface, 2021 IEEE 5th Information Technology,Networking,Electronic and Automation Control Conference (ITNEC), 10.1109/ITNEC52019.2021.9587093, 2021.10.
19. Nyi Nyi Tun, Fumiya Sanuki, `Keiji Iramina, Electroencephalogram-Electromyogram Functional Coupling and Delay Time Change Based on Motor Task Performance, Sensors, https://doi.org/10.3390/s21134380, 21, 13, 4380-1-4380-24, 2021.05, Synchronous correlation brain and muscle oscillations during motor task execution is termed as functional coupling. Functional coupling between two signals appears with a delay time which can be used to infer the directionality of information flow. Functional coupling of brain and muscle depends on the type of muscle contraction and motor task performance. Although there have been many studies of functional coupling with types of muscle contraction and force level, there has been a lack of investigation with various motor task performances. Motor task types play an essential role that can reflect the amount of functional interaction. Thus, we examined functional coupling under four different motor tasks: real movement, intention, motor imagery and movement observation tasks. We explored interaction of two signals with linear and nonlinear information flow. The aim of this study is to investigate the synchronization between brain and muscle signals in terms of functional coupling and delay time. The results proved that brain–muscle functional coupling and delay time change according to motor tasks. Quick synchronization of localized cortical activity and motor unit firing causes good functional coupling and this can lead to short delay time to oscillate between signals. Signals can flow with bidirectionality between efferent and afferent pathways.
20. Hadriana Iddas, Keiji Iramina, Directed EEG Functional Connectivity Features to Reveal Different Attention Indexes Using Hierarchical Clustering, IEEE Access, 10.1109/ACCESS.2021.3072224, 9, 59328-59335, 2021.04, Functional connectivity related to familiarity has recently been investigated in the context of various stimuli (e.g., words, faces, pictures, music, and video). However, the directed functional connectivity patterns with different attention indexes as a response to familiar/unfamiliar stimuli remain unclear. In the current study, we employed the Directed Transfer Function (DTF) to estimate the information flow between brain areas. This method was reported to be practically robust to volume conduction. Furthermore, the hierarchical clustering approach was utilized to group subjects based on the attention index, i.e., the alpha/theta ratio of fronto-central (frontal to central and central to frontal) features. Three major findings were revealed from this study. First, all subjects had different attention indexes when they watched familiar/unfamiliar videos. Then, subjects were sorted into three groups: low index (LI), middle index (MI), and high index (HI). Second, a competition between two states (familiar/unfamiliar) showed that the information flows of familiar stimuli were greater than unfamiliar stimuli, which involved significant effects in the frontal, temporal, and parietal areas. Third, comparison between groups (LI/MI/HI) demonstrated that the frontal and central regions were the primary sources that distributed information flows to almost the whole brain, particularly during familiar conditions. This result indicates that these two regions may play an important role in attentional processing..
21. Sheng Ge, Yichuan Jiang, Mingming Zhang, Ruimin Wang, Keiji Iramina, Pan Lin, Yue Leng, SSVEP-Based Brain-Computer Interface With a Limited Number of Frequencies Based on Dual-Frequency Biased Coding, IEEE Transactions on Neural Systems and Rehabilitation Engineering , 10.1109/TNSRE.2021.3073134, Vol. 29, 760-769, 2021.04.
22. Peng Wang, Jing He, Wenli Lan, Hui Yang, Yue Leng, Ruimin Wang, Keiji Iramina, Sheng Ge, A Hybrid EEG-fNIRS Brain-Computer Interface Based on Dynamic Functional Connectivity and Long Short-Term Memory, 2021 IEEE 5th Advanced Information Technology, Electronic and Automation Control Conference (IAEAC), 10.1109/IAEAC50856.2021.9390839, 2214-2219, 2021.03.
23. A. Wicaksono, T. Mengko, K. Iramina, Investigation of EEG Signal Response Using Event-Related Potential (ERP) Towards Ishihara Pseudo-Isochromatic Visual Stimulus, 2020 IEEE Signal Processing in Medicine and Biology Symposium (SPMB), 10.1109/SPMB50085.2020.9353640, 2020.12.
24. Thanate Angsuwatanakul, Jamie O'Reilly, Kajornvut Ounjai, Boonserm Kaewkamnerdpong, Keiji Iramina, Multiscale entropy as a new feature for EEG and fNIRS analysis, Entropy, 10.3390/e22020189, 22, 2, 2020.02, The present study aims to apply multiscale entropy (MSE) to analyse brain activity in terms of brain complexity levels and to use simultaneous electroencephalogram and functional near-infrared spectroscopy (EEG/fNIRS) recordings for brain functional analysis. A memory task was selected to demonstrate the potential of this multimodality approach since memory is a highly complex neurocognitive process, and the mechanisms governing selective retention of memories are not fully understood by other approaches. In this study, 15 healthy participants with normal colour vision participated in the visual memory task, which involved the making the executive decision of remembering or forgetting the visual stimuli based on his/her own will. In a continuous stimulus set, 250 indoor/outdoor scenes were presented at random, between periods of fixation on a black background. The participants were instructed to make a binary choice indicating whether they wished to remember or forget the image; both stimulus and response times were stored for analysis. The participants then performed a scene recognition test to confirm whether or not they remembered the images. The results revealed that the participants intentionally memorising a visual scene demonstrate significantly greater brain complexity levels in the prefrontal and frontal lobe than when purposefully forgetting a scene; p
25. Van Cam Thi Le, Nhan Thanh Le, Hai Ngoc Nguyen, Dang Cao Le, Keiji Iramina, Controlling the Wheelchair by Eye Movements Using EEG, 7th International Conference on the Development of Biomedical Engineering in Vietnam, BME 2018 7th International Conference on the Development of Biomedical Engineering in Vietnam (BME7) - Translational Health Science and Technology for Developing Countries, 2018, 10.1007/978-981-13-5859-3_41, 231-234, 2020.01, In this study, we propose a method to control the wheelchair by eye movement using Electroencephalography (EEG). Firstly, we collect EEG signal by five types of eye movement: Blink, Double blink, look at Right, look at Left and Relax. These movements correspond to five directions of wheelchair motion: Go forward, Go backward, Turn right, Turn left and Stop. After that, the offline EEG signal is analyzed using MATLAB to find out the classified threshold of the signal amplitude in Alpha band and Delta band. Finally, an effective algorithm is built allowing us to identify the type of eye movement and control the external device—the powered wheelchair. As the result, the average accuracy for five motion directions (Go forward, Go backward, Turn right, Turn left and Stop) are 92.333, 93, 81.667, 86.667 and 83% respectively. With this study, we expect it can give people the help they need and be applied to many fields in the near future..
26. Ruimin Wang, Sheng Ge, Noha Mohsen Zommara, Karine Ravienna, Teodora Espinoza, Keiji Iramina, Consistency and dynamical changes of directional information flow in different brain states
A comparison of working memory and resting-state using EEG, NeuroImage, 10.1016/j.neuroimage.2019.116188, 203, 2019.12, Several recent studies have reported a frequency-dependent directional information flow loop in resting-state networks by phase transfer entropy, comprising an anterior-to-posterior information flow in the theta band and a posterior-to-anterior information flow in the alpha band. However, the functional roles of this information flow loop remain unclear. In the current study, we compared information flow patterns in four different brain states using electroencephalography: resting-state, fixation, working memory (WM) encoding and WM maintenance. An auditory (pure tones) WM span task was carried out. A consistent anterior-to-posterior information flow in the theta band and an opposite pattern in the alpha band were found in all four segments. Flows in both patterns were enhanced during WM encoding. In contrast, a prefrontal-to-central information flow in the alpha band was dominant during the resting-state. In addition, enhanced information flows from right temporal to other brain regions in the theta band were found during WM processing (WM encoding and maintenance). Comparison of the consistency and dynamical changes of information flows in these four brain states indicated their functional roles in central executive processes, internal attention, WM information maintenance, and the right-hemisphere advantage in pure tone processing..
27. Tetsuya Torii, Aya Sato, Masakuni Iwahashi, Keiji Iramina, Using repetitive paired-pulse transcranial magnetic stimulation for evaluation motor cortex excitability, AIP Advances, 10.1063/1.5129299, 9, 12, 2019.12, In this study, we investigated the effects of repetitive paired-pulse transcranial magnetic stimulation (TMS) on the motor cortex excitability. The interstimulus intervals (ISIs) between the conditioning (first) stimulus and test (second) stimulus were 1,000, 200 and 100 ms. A total of 20 stimuli were delivered to the primary motor cortex using paired-pulse TMS at 10 s intervals, and the intensity of the magnetic stimulus was 110% of the resting motor threshold for each subject. For all ISIs, there was no significant correlation between the number of stimuli and the motor evoked potential (MEP) amplitude. However, there was slight correlation between the number of stimuli and the MEP amplitude in the 200 and 100 ms ISIs (200 and 100 ms ISIs: Approximately r =-0.40; 1,000 ms ISI: r =-0.17). In addition, MEP amplitude increased during the second paired pulse stimulation when an ISI of 200 ms was used, but it decreased dramatically when an ISI of 100 ms was used. In contrast, MEP amplitude did not change significantly when a 1,000 ms ISI was employed. Therefore, 10 consecutive paired-pulse TMS stimuli with a 1,000 ms ISI may not have a cumulative effect on cortical excitability. Previous studies used a long duration (e.g., 6 minutes or longer by 0.1 Hz magnetic stimulation) of magnetic stimulation to evaluate cortical excitability. In evaluating cortical excitability by magnetic stimulation, it is important to shorten the period to reduce the subject's burden and to prevent body movement. Thus, our present findings suggest that repetitive paired-pulse TMS with an ISI of 1,000 ms is suitable for the rapid evaluation of cortical excitability..
28. Sheng Ge, Peng Wang, Hui Liu, Pan Lin, Junfeng Gao, Ruimin Wang, Keiji Iramina, Quan Zhang, Wenming Zheng, Neural Activity and Decoding of Action Observation Using Combined EEG and fNIRS Measurement, Frontiers in Human Neuroscience, 10.3389/fnhum.2019.00357, 13, 2019.10, In a social world, observing the actions of others is fundamental to understanding what they are doing, as well as their intentions and feelings. Studies of the neural basis and decoding of action observation are important for understanding action-related processes and have implications for cognitive, social neuroscience, and human-machine interaction (HMI). In the current study, we first investigated temporal-spatial dynamics during action observation using a combined 64-channel electroencephalography (EEG) and 48-channel functional near-infrared spectroscopy (fNIRS) system. We measured brain activation while 16 healthy participants observed three action tasks: (1) grasping a cup with the intention of drinking; (2) grasping a cup with the intention of moving it; and (3) touching a cup with an unclear intention. The EEG and fNIRS source analysis results revealed the dynamic involvement of both the mirror neuron system (MNS) and the theory of mind (ToM)/mentalizing network during action observation. The source analysis results suggested that the extent to which these two systems were engaged was determined by the clarity of the intention of the observed action. Based on the difference in neural activity observed among different action-observation tasks in the first experiment, we conducted a second experiment to classify the neural processes underlying action observation using a feature classification method. We constructed complex brain networks based on the EEG and fNIRS data. Fusing features from both EEG and fNIRS complex brain networks resulted in a classification accuracy of 72.7% for the three action observation tasks. This study provides a theoretical and empirical basis for elucidating the neural mechanisms of action observation and intention understanding, and a feasible method for decoding the underlying neural processes..
29. Nyi Nyi Tun, Keiji Iramina, RELATIONSHIP BETWEEN EMG ANDERD/ERS DURING MOTOR IMAGERY BASED ON THE MUSCLE CONTRACTION TYPES, 2019 Joint International Conference on Science, Technology and Innovation, Mandalay by IEEE, 117-122, 2019.09.
30. Ruimin Wang, Sheng Ge, Noha Mohsen Zommara, WenWei Zheng, Keiji Iramina, Auditory White Noise Affects Left/Right Visual Working Memory in an Opposite Pattern, 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 10.1109/EMBC.2019.8856688, 2719-2722, 2019.08.
31. Nyi Nyi Tun, Keiji Iramina, Investigation of the relation between muscle activity and motor imagery based on the muscle contraction types, Proceedings of Life Engineering Symposium 2019(LE 2019), 0112-0117, 2019.08.
32. Ruimin Wang, Sheng Ge, Noha Mohsen Zommara, Wenwei Zheng, Keiji Iramina, Auditory White Noise Affects Left/Right Visual Working Memory in an Opposite Pattern, 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019, 10.1109/EMBC.2019.8856688, 2719-2722, 2019.07, Adding auditory white noise (WN) to the environment has been considered to be a promising way to enhance the memory performance of children with attention deficit/hyperactivity disorder (ADHD) but disrupt that of non-ADHD children. To explore the exact mechanism behind WN benefits, we did a bilateral color-memory task with different WN conditions. A bilateral color-square array was displayed on one display. Only one side colors were asked to be remembered in a trial. Our experiment found that the memory accuracy of left visual memory was improved with WN, especially when WN was displayed via left earphone at encoding and maintenance periods. However, the right visual memory showed a reduced performance tendency with WN. Thus, the WN affects left/right visual working memory in an opposite pattern. Using time-frequency analysis, we found an enhanced lower-alpha activity over the left occipitotemporal lobe. We conclude that the induced lower-alpha activity at the left occipitotemporal lobe might be helpful to inhibit information processing of left hemisphere..
33. Tustanah Phukhachee, Suthathip Maneewongvatana, Thanate Angsuwatanakul, Keiji Iramina, Boonserm Kaewkamnerdpong, Investigating the effect of intrinsic motivation on alpha desynchronization using sample entropy, Entropy, 10.3390/e21030237, 21, 3, 2019.03, The effect of motivation and attention could play an important role in providing personalized learning services and improving learners toward smart education. These effects on brain activity could be quantified by EEG and open the path to analyze the efficiency of services during the learning process. Many studies reported the appearance of EEG alpha desynchronization during the attention period, resulting in better cognitive performance. Motivation was also found to be reflected in EEG. This study investigated the effect of intrinsic motivation on the alpha desynchronization pattern in terms of the complexity of time series data. The sample entropy method was used to quantify the complexity of event-related spectral perturbation (ERSP) of EEG data. We found that when participants can remember the stimulus, ERSP was significantly less complex than when they cannot. However, the effect of intrinsic motivation cannot be defined by using sample entropy directly. ERSP's main effect showed that motivation affects the complexity of ERSP data; longer continuous alpha desynchronization patterns were found when participants were motivated. Therefore, we introduced an algorithm to identify the longest continuous alpha desynchronization pattern. The method allowed us to understand that intrinsic motivation has an effect on recognition at the frontal and left parietal area directly..
34. Fadilla Zennifa, Keiji Iramina, Quantitative formula of blink rates-pupillometry for attention level detection in supervised machine learning, IEEE Access, 10.1109/ACCESS.2019.2929596, 7, 96263-96271, 2019.01, Attention is a condition when someone concentrates on a specific task while ignoring other perceivable information. Numerous methods of attention level detection such as observation, self-assessment, and objective performance have been applied especially in supervised machine learning. But those methods tend to be delayed, sporadic, not at the moment in time, and based on participant cognitive ability. This study proposed a new labeling method for attention level detection by using quantitative evaluation formula based on blink rates and pupillometry. Comparison in error detection between self-assessment, observation, and objective performance has been done in this study. After that, this study investigated the effect of attention level based on self-assessment toward blink rates and pupillometry. The result shown blink rates in low attention is higher than high attention. On the other hand, pupillometry in low attention is smaller than high attention. The effect of attention levels toward pupillometry and blink rates are extracted into several algorithms. The result from experimental procedure shown quantitative evaluation formula has percentage error less than 15% compared with self-assessment. Overall, these results demonstrated that the proposed method can be used to be data labeling for other physiological signals such as electroencephalograph (EEG), electrocardiograph (ECG), and near-infrared spectroscopy (NIRS). After that, this quantitative formula was applied to EEG-ECG-NIRS for attention level detection. Two-electrode wireless EEG, a wireless ECG, and two wireless channels NIRS has been used to detect attention level during tasks load. Our result has shown the accuracy system 82.31%..
35. A. Sato, T. Torii, M. Iwahashi, Keiji Iramina, Alterations in Motor Cortical Excitability Induced by Peripheral Stimulation with Magnetic Stimulation, IEEE Transactions on Magnetics, 10.1109/TMAG.2018.2851358, 54, 11, 2018.11, The conditioning of cortical excitability by transcranial magnetic stimulation (TMS) has become a valuable technique to promote recovery of motor function after stroke. As TMS is not used in all patients, we investigated the hypothesis that peripheral stimulation may have an adjustment effect on motor cortical excitability. Our experimental paradigm was divided into three phases. In the first phase, TMS was delivered to the left or right primary motor cortex to induce a motor evoked potential (MEP) from the contralateral first dorsal interosseous muscle. The measured MEPs in this phase were used to evaluate the effect of peripheral stimulation. In the second phase, 1 Hz magnetic stimulation was applied over the contralateral or ipsilateral forearm for motor cortex as peripheral stimulation. In the third phase, the MEP was evoked by TMS and recorded using the same setting as the first phase. We found that a decrease in MEP amplitude was observed in the left motor cortex following peripheral stimulation over the right forearm. By contrast, the MEP amplitude was not altered in the right motor cortex by peripheral stimulation over the left forearm. An increase in MEP amplitude was observed in the ipsilateral motor cortex induced by peripheral stimulation over the left or right forearm. We also found that by changing the MEP amplitude, the motor cortex excitability varied according to magnetic stimulation of the forearm. These data suggest that peripheral stimulation may have an adjustment effect on motor cortical excitability, via changes in the stimulus site..
36. Fadilla Zeniffa, Sho Ageno Shota Hatano Keiji Iramina, Hybrid System for Engagement Recognition during Cognitive Tasks Using a CFS+ KNN Algorithm, Sensors, 10.3390/s18113691, 18, 11, 3691 1-3891 16, 2018.10.
37. A. Sato, T. Torii, M. Iwahashi, Keiji Iramina, Alteration in motor cortical excitability induced by peripheral stimulation with magnetic stimulation, 2018 IEEE International Magnetic Conference, INTERMAG 2018 2018 IEEE International Magnetic Conference, INTERMAG 2018, 10.1109/INTMAG.2018.8508511, 2018.10, In recent years, the conditioning of cortical excitability has attracted attention as a valuable function to the recovery of motor function after stroke. Motor cortical excitability can be altered by transcranial magnetic stimulation (TMS), and by peripheral stimulation [1-3]. This study focused attention on the effects of peripheral stimulation on cortical excitability because TMS is not provided for all patients. Many studies of peripheral stimulation have not focused on the inhibition of cortical excitability. This study investigated the possibility that peripheral stimulation has an adjustment effect of motor cortical excitability, by examining the inhibition of cortical excitability induced by peripheral stimulation. This study used magnetic stimulation as peripheral stimulation, because the eddy currents induced by magnetic stimulation stimulate deeper tissue regions..
38. Yichuan Jiang, Xinyu Chen, Hui Liu, Yue Leng, Yuankui Yang, Pan Lin, Junfeng Gao, Ruiming Wang, Keiji Iramina, Sheng Ge, Rapid detection of targets from complex backgrounds based on eye-tracking data, 2nd International Conference on Computer Science and Application Engineering, CSAE 2018 Proceedings of 2nd International Conference on Computer Science and Application Engineering, CSAE 2018, 10.1145/3207677.3278051, 2018.10, In this study1, we used a remote eye-tracker in a head-free setting to measure target detection in visual scenes. Participants underwent two kinds of tasks that were designed to simulate different situations and to study the validity and accuracy of the remote eye-tracking system. We found that the average target detection rate in the simulation task reached 88.95%, whereas in the real scene task the average accuracy was 83.20%. Our results show that the remote eye-tracker possesses enough precision to be used for the measurement of target detection in complex visual scenes..
39. Sheng Ge Yan-Hua Shi Rui-Min Wang Pan Lin Jun-Feng Gao Gao-Peng Sun Keiji Iramina Yuan-Kui Yang Yue Leng Hai-Xian Wang Wen-Ming Zheng, Sinusoidal Signal Assisted Multivariate Empirical Mode Decomposition for Brain–Computer Interfaces, IEEE Journal of Biomedical and Health Informatics, 10.1109/JBHI.2017.2775657, 22, 5, 1373-1384, 2018.09.
40. Gaopeng Sun, Yanhua Shi, Hui Liu, Yichuan Jiang, Pan Lin, Junfeng Gao, Ruimin Wang, Yue Leng, Yuankui Yang, Sheng Ge, Keiji Iramina, The sinusoidal assisted MEMD based CCA method for SSVEP based BCI improvement, 10th International Conference on Computational Intelligence and Communication Networks, CICN 2018 Proceedings - 2018 10th International Conference on Computational Intelligence and Communication Networks, CICN 2018, 10.1109/CICN.2018.8864953, 65-69, 2018.08, Although the canonical correlation analysis (CCA) algorithm has been applied successfully to SSVEP detection, artifacts and unrelated brain activities may influence the performance of the steady state visual evoked potential (SSVEP) based brain-computer interfaces (BCI) system. Extracting the characteristic frequency sub-bands is an effective method to enhance the signal-to-noise-ratio of SSVEP signals. The sinusoid-assisted MEMD (SA-MEMD) algorithm is a powerful method for spectral decomposition. In this study, we propose an SA-MEMD based CCA method for SSVEP detection. The results suggest that the SA-MEMD based CCA algorithm is a useful method in the detection of typical SSVEP signals. The classification accuracy achieved 88.3% in a 4 s time window and there was a 2.8% improvement compared with the standard CCA algorithm..
41. A. Sato, T. Torii, M. Iwahashi, K. Iramina, Alterations in Motor Cortical Excitability Induced by Peripheral Stimulation With Magnetic Stimulation, IEEE Transactions on Magnetics, 10.1109/TMAG.2018.2851358, 1-4, 2018.06.
42. Gaopeng Sun Hui Liu Yanhua Shi Yue Leng Pan Lin Ruimin Wang Yuankui Yang Junfeng Gao Haixian Wang Keiji Iramina Sheng Ge, One class support vector machine based filter for improving the classification accuracy of SSVEP BCI, 2017 10th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics (CISP-BMEI), 10.1109/CISP-BMEI.2017.8302171, 2018.02.
43. Kazuhisa Nojima, Keiji Iramina, Relationship between rTMS effects and MEP features before rTMS, Neuroscience Letters, 10.1016/j.neulet.2017.11.030, 664, 110-115, 2018.01, Repetitive transcranial magnetic stimulation (rTMS) is a promising method for use in the clinical field, as it can induce modulation of cortical excitability. Generally, rTMS inhibits the motor cortex when delivered at less than 1 Hz. However, it has been indicated that a facilitative effect is induced by 1 Hz rTMS, depending on the stimulation parameters and the individual. Therefore, the aim of this study was to investigate the features of the subject that could affect the 1 Hz rTMS effect when rTMS stimulus conditions change. First, motor evoked potentials (MEP) were measured under rTMS conditions with a variety of stimulus intensities and numbers of pulses. The MEP features before rTMS and the MEP modulation by the rTMS were then analyzed. Furthermore, correlations between the MEP features and the rTMS effect were investigated. It was found that the MEP amplitude and MEP onset before rTMS can influence the rTMS effect. Furthermore, negative correlations were found between these MEP features and the rTMS effect. MEPs with a small amplitude and early latency were little influenced by the inhibitive effect of 1 Hz rTMS, while MEPs with a large amplitude and late latency were readily affected by the inhibitive effect of 1 Hz rTMS. In this study, we focused on the MEP features before rTMS and identified the features of the subject that could influence the rTMS effect when the rTMS stimulus condition was changed..
44. A. Sato, X. Liu, T. Torii, M. Iwahashi, K. Iramina, Alteration of the motor cortex excitability by modulation of the stimulus parameter of peripheral stimulation, 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME 2016 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME6, 10.1007/978-981-10-4361-1_79, 467-471, 2018.01, Transcranial magnetic stimulation (TMS) is known to elicit a conditioning effect on cortical excitability. The purpose of this study was to investigate changes in cortical excitability induced by peripheral stimulation with differing frequency and stimulation site. A magnetic stimulator with a flat figure-eight coil was used for TMS and was performed on the left primary motor cortex. The electrical stimulation and magnetic stimulation were used in peripheral stimulation and the stimulus sites were the right and left supination of the forearm. Peripheral stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz. Alterations of cortical excitability induced by peripheral stimulation were evaluated by comparing the mean of the motor evoked potential amplitude elicited by TMS each before and after peripheral stimulation. We found that cortical excitability varied according to the stimulation site and frequency in both the electrical and magnetic stimulation over the forearm. The inhibition of cortical excitability was observed in both 1 Hz electrical and magnetic stimulation over the right forearm. In contrast, the facilitation of cortical excitability was observed at 1 Hz electrical and magnetic stimulation over the left forearm, and it was confirmed for both the right and left forearms at 10 Hz electrical and magnetic stimulation. Moreover, regarding the alteration of cortical excitability induced by peripheral stimulation, it was confirmed that magnetic stimulation has more the significant difference than electrical stimulation. We suggest that peripheral stimulation by electrical and magnetic stimulation have a similar effect to TMS, and can induce both facilitation and inhibition of cortical excitability. Moreover, in the case of peripheral stimulation of the same stimulus frequency, we expect that the magnetic stimulation has more the significant effect than electrical stimulation to cortical excitability..
45. Ruimin Wang, Keiji Iramina, Sheng Ge, An improved multiple LASSO model for steady-state visual evoked potential detection, 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME 2016 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME6, 10.1007/978-981-10-4361-1_72, 427-430, 2018.01, Improving the classification accuracy in brain–computer interface (BCI) with a short data length is important to increase the BCI system’s information transfer rate. Least absolute shrinkage and selection operator (LASSO) has been examined to be an effective way to detect the steady-state visual evoked potential (SSVEP) signals with a short time window. In this paper, an improved multiple LASSO model for SSVEP detection is proposed, which can process multichannel electroencephalogram (EEG) signals without electrode selection. EEG data from twelve healthy volunteers were used to test the improved multiple LASSO model. Compared with the traditional LASSO model, the improved multiple LASSO model gives a significantly better performance with multichannel EEG data..
46. T. Hayami, K. Iramina, X. Chen, Computer simulation of nerve conduction study of a sural nerve to evaluate human peripheral nervous system, 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME 2016 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME6, 10.1007/978-981-10-4361-1_78, 461-465, 2018.01, Nerve conduction study is a test to examine the function of electric signal transmission at the trunk of a peripheral nerve, which is an effective method for the diagnosis of diabetes to quantify the peripheral numbness and to evaluate the stage of this complication. In a routine test, the feature to measure in the electric potential waveform observed in this test is limited to the velocity and the amplitude of the peaks. To make the measurement more precise, the production process of the electric potential waveform should be observed carefully. In this study, nerve conduction study of a sural nerve, which is the most popular for the patients with diabetes, was simulated in a computer using general cable equation and neuroanatomical data. As a result, the approximate electric potential waveform was reproduced, whereas the conduction velocity of the peaks was not completely conformed to the physiological data..
47. Kurniawan Eka Permana, Tsuyoshi Okamoto, Keiji Iramina, Single channel electroencephalogram measurement with multi-scale entropy analysis for evaluating day time sleep, 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME 2016 6th International Conference on the Development of Biomedical Engineering in Vietnam, BME6, 10.1007/978-981-10-4361-1_73, 431-435, 2018.01, A general method for evaluating sleep is by identifying the stages of sleep from electroencephalogram (EEG), electrooculogram (EOG) and electromyogram (EMG). Unfortunately, visual sleep scoring is usually subjective and time consumptive. This was the reason for the development of automatic sleep staging based on multi EEG, EOG, and EMG. Recently, automatic sleep stages based on single channel EEG is also being developed to reduce the unnecessary number of wire. The problem is that this approach needs 90 min to complete the sleep stages cycle while normal short nap or day-time sleep experiment duration is usually less than 60 min. With this less than 60 min’ sleep duration issue, the purpose of this research is to develop a single channel EEG evaluation method by measuring changes in amplitude power of EEG at a specific time of day time sleep. The amplitude difference in term of a complexity of EEG will be used as an experiment index. We calculated EEG complexity with Multi-Scale Entropy (MSE) for day-time sleep experiment. The average entropy as the final result from the method could determine the EEG complexity of frequency power and have a negative correlation with the delta wave. Based on this result, average entropy was used and had demonstrated a significant difference. MSE method could be useful for single channel EEG evaluation and significantly perform better understanding of day-time sleep..
48. Gaopeng Sun, Yanhua Shi, Hui Liu, Yichuan Jiang, Pan Lin, Junfeng Gao, Ruimin Wang, Yue Leng, Yuankui Yang, Iramina Keiji, Sheng Ge, Sinusoid-assisted MEMD-based CCA method for SSVEP-based BCI improvement, 2018 International Conference on Image and Video Processing, and Artificial Intelligence, IVPAI 2018 2018 International Conference on Image and Video Processing, and Artificial Intelligence, 10.1117/12.2514420, 2018.01, Although the canonical correlation analysis (CCA) algorithm has been applied successfully to steady-state visual evoked potential (SSVEP) detection, artifacts and unrelated brain activities may affect the performance of SSVEP-based brain-computer interface systems. Extracting the characteristic frequency sub-bands is an effective method of enhancing the signal-to-noise-ratio of SSVEP signals. The sinusoid-assisted multivariate extension of empirical mode decomposition (SA-MEMD) algorithm is a powerful method of spectral decomposition. In this study, we propose an SA-MEMD-based CCA method for SSVEP detection. Experimental results suggest that the SA-MEMD-based CCA algorithm is a useful method for the detection of typical SSVEP signals. The SA-MEMD-based CCA algorithm reached a classification accuracy of 88.3% for a window of 4 s and outperformed the standard CCA algorithm by 2.8%..
49. Chayapol Chaiyanan; Keiji Iramina; Thanate Angsuwatanakul; Boonserm Kaewkamnerdpong, Response time analysis on implicit learning induced by cognitive tasks toward developing ADHD treatment, Proceedings of 10th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON.2017.8229133, 2017.11, Attention Deficit Hyperactivity Disorder is a neurological disorder that affects many children in the world. Many scientists have speculated that behavior therapy is an essential part of treatment for people with ADHD. One of the promising behavioral therapy is neurofeedback therapy. Using neurofeedback, therapist can learn how to modulate patients' brain activity by adjusting the training regimen. Identifying when a patient achieve implicit learning event can potentially help in designing the neurofeedback treatment to help people with ADHD. According to past research, it was speculated that implicit learning and children with ADHD could have an atypical relationship. The aim of this paper to analyze response times of healthy people while they perform cognitive tasks to differentiate between people who has gained implicit knowledge and those who did not. The data showed that there is a clear distinction between people who had gained implicit knowledge and those that did not..
50. Sheng Ge; Yan-Hua Shi; Rui-Min Wang; Pan Lin; Jun-Feng Gao; Gao-Peng Sun; Keiji Iramina; Yuan-Kui Yang; Yue Leng; Haixian Wang; Wenming Zheng, Sinusoidal Signal Assisted Multivariate Empirical Mode Decomposition for Brain-Computer Interfaces, IEEE Journal of Biomedical and Health Informatics, 10.1109/JBHI.2017.2775657, 2017.11, Abstract:
A brain-computer interface (BCI) is a communication approach that permits cerebral activity to control computers or external devices. Brain electrical activity recorded with electroencephalography (EEG) is most commonly used for BCI. Noise-assisted multivariate empirical mode decomposition (NA-MEMD) is a data-driven time-frequency analysis method that can be applied to nonlinear and nonstationary EEG signals for BCI data processing. However, because white Gaussian noise occupies a broad range of frequencies, some redundant components are introduced. To solve this leakage problem, in this study, we propose using a sinusoidal assisted signal that occupies the same frequency ranges as the original signals to improve MEMD performance. To verify the effectiveness of the proposed sinusoidal signal assisted MEMD (SA-MEMD) method, we compared the decomposition performances of MEMD, NA-MEMD, and the proposed SA-MEMD using synthetic signals and a real-world BCI dataset. The spectral decomposition results indicate that the proposed SA-MEMD can avoid the generation of redundant components and over decomposition, thus substantially reduce the mode mixing and misalignment that occurs in MEMD and NA-MEMD. Moreover, using SA-MEMD as a signal preprocessing method instead of MEMD or NA-MEMD can significantly improve BCI classification accuracy, which indicates that SA-MEMD is a powerful spectral decomposition method for BCI..
51. Kazuhisa Nojima, Keiji Iramina, Prediction of Cortical Excitability Induced by 1 Hz rTMS, TEEE:IEEJ Transactions on Electrical and Electronic Engineering, 12, 4, in press, 2017.10, The aim of this study was to develop a model that predicts the effects of repetitive transcranial magnetic stimulation (rTMS), allowing stimulation parameters for individual subjects. Modulation of cortical excitability induced by rTMS can be evaluated through motor evoked potential (MEP) amplitude. We established a model that can predict how MEP amplitude is modulated by entering rTMS intensities and numbers of pulses. First, MEPs were measured under various rTMS conditions of stimulus intensity and number of pulses. Then, cluster analysis was performed to classify subjects, as rTMS affects individuals differently. Finally, the predictive model was created by applying multiple regression analysis to data from each cluster. As a result, subjects were classified into two groups. For Cluster A, the inhibitive effect of rTMS was difficulty induced and facilitative effect was induced depending on the stimulus condition. Then, the predictive errors had an average of 46.19%. For Cluster B, the inhibitive effect was strongly induced by rTMS, and the errors had an average of 20.25%. In the model, for both clusters, about 90% of measurement data were in the predictive interval. This report describes the development of our prediction model and its efficiency..
52. Gaopeng Sun; Hui Liu; Yanhua Shi; Yue Leng; Pan Lin; Ruimin Wang; Yuankui Yang; Junfeng Gao; Haixian Wang; Keiji Iramina; Sheng Ge, One class support vector machine based filter for improving the classification accuracy of SSVEP BCI, Image and Signal Processing, BioMedical Engineering and Informatics (CISP-BMEI), 2017 10th International Congress , 10.1109/CISP-BMEI.2017.8302171, 2017.10, Canonical correlation analysis (CCA) has been proved to be effective in the detection of steady state visual evoked potential (SSVEP) signals. However, the CCA method only chooses the frequency in the reference mode that corresponds to the maximum correlation value as the target. This may make the CCA output less robust. In this study, we propose a one-class support vector machine based filter to filter the sequences of correlation values in the process of the detection of SSVEP signals. The results demonstrate that the classification accuracy improved over different time windows for all subjects and the improvement achieved approximately 10% for some subjects. Moreover, the ratio of instructions that were filtered incorrectly was relative low (less than 5%) if the SSVEP signals were generated effectively..
53. Hui Liu; Wengming Zheng; Gaopeng Sun; Yanhua Shi; Yue Leng; Pan Lin; Ruimin Wang; Yuankui Yang; Jun-feng Gao; Haixian Wang; Keiji Iramina; Sheng Ge, Action understanding based on a combination of one-versus-rest and one-versus-one multi-classification methods, Image and Signal Processing, BioMedical Engineering and Informatics (CISP-BMEI), 2017 10th International Congress, 10.1109/CISP-BMEI.2017.8302159, 2017.10, When people observe the actions of others, they naturally try to understand the underlying intentions. This behavior is called action understanding, and it has an important influence on mental development, language comprehension, and socialization. In this study, we used functional near-infrared spectroscopy (fNIRS) to obtain brain signals related to action understanding and then classified different intentions. Aiming to overcome the drawbacks of traditional multiclass classification methods of one-versus-rest (OVR) and one-versus-one (OVO), in this paper, we propose a new effective method to solve multiclass classification that is a combination of OVR and OVO. Compared with OVO, this new method effectively improved the accuracy of four-class classification from 25% to 48%..
54. Ruimin Wang; Risako Kamezawa; Aiko Watanabe; Keiji Iramina, EEG alpha power change during working memory encoding in adults with different memory performance levels, Proceedings of 39th Engineering in Medicine and Biology Society EMBC2017, 10.1109/EMBC.2017.8036990, 982-985, 2017.09, Peripheral stimulation is known to influence the state of cortical excitability. The purpose of this study is to investigate whether peripheral magnetic stimulation has similar effects on cortical excitability to transcranial magnetic stimulation (TMS). A magnetic stimulator with a flat figure-of-eight coil was used for both TMS, and peripheral magnetic stimulation applied to the bilateral forearms. TMS was performed on the left primary motor cortex to evaluate influence of the peripheral magnetic stimulation, and motor evoked potential (MEP) was measured from the right first dorsal interosseous. Peripheral magnetic stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz, to the stimulus sites on the right and left supination of the forearm. The effects of peripheral magnetic stimulation were evaluated by comparing the mean MEP amplitude elicited by TMS before
and after peripheral magnetic stimulation. We found that cortical excitability varied according to the stimulation site and frequency of the peripheral magnetic stimulation. The inhibition of cortical excitability was observed following 1 Hz peripheral magnetic stimulation over the right forearm (p
55. Tustanah Phukhachee; Suthathip Maneewongvatana; Boonserm Kaewkamnerdpong; Thanate Angsuwatanakul; Keiji Iramina, Measuring brain activation by using baseline-normalized event-related spectral perturbation in working memory task, Proceedings of 39th Engineering in Medicine and Biology Society EMBC2017, 10.1109/EMBC.2017.8037826, 4379-4382, 2017.09, Understanding the cognitive function of human brain is an important step in providing scientific evidence which could help us improve the condition of memory disorders, slow down its progress or at least help the patients retain some important matters. In this study, we aimed to provide additional scientific evidence with more insight on how the brain functions at a good/bad cognitive state than the usual statistical analysis. We introduced the brain activation measurement using baseline-normalized ERSP to determine the activation of EEG data from stimuli. These active points over a period of time could reflect brain synchronization due to stimuli. We also demonstrated the use of proposed measure on attention working memory data. The results indicate the potential of using the proposed measurement in categorizing the brain cognitive state and identifying some important factors to provide additional evidence to the field in the future..
56. Jongseung Lee; Nobutaka Mukae; Jumpei Arata; Hiroyuki Iwata; Keiji Iramina; Koji Iihara; Makoto Hashizume, A multichannel-near-infrared-spectroscopy-triggered robotic hand rehabilitation system for stroke patients, Proceedings of 2017 International Conference on Rehabilitation Robotics (ICORR), 10.1109/ICORR.2017.8009239, 158-163, 2017.08, There is a demand for a new neurorehabilitation modality with a brain-computer interface for stroke patients with insufficient or no remaining hand motor function. We previously developed a robotic hand rehabilitation system triggered by multichannel near-infrared spectroscopy (NIRS) to address this demand. In a preliminary prototype system, a robotic hand orthosis, providing one degree-of-freedom motion for a hand's closing and opening, is triggered by a wireless command from a NIRS system, capturing a subject's motor cortex activation. To examine the feasibility of the prototype, we conducted a preliminary test involving six neurologically intact participants. The test comprised a series of evaluations for two aspects of neurorehabilitation training in a real-time manner: classification accuracy and execution time. The effects of classification-related factors, namely the algorithm, signal type, and number of NIRS channels, were investigated. In the comparison of algorithms, linear discrimination analysis performed better than the support vector machine in terms of both accuracy and training time. The oxyhemoglobin versus deoxyhemoglobin comparison revealed that the two concentrations almost equally contribute to the hand motion estimation. The relationship between the number of NIRS channels and accuracy indicated that a certain number of channels are needed and suggested a need for a method of selecting informative channels. The computation time of 5.84 ms was acceptable for our purpose. Overall, the preliminary prototype showed sufficient feasibility for further development and clinical testing with stroke patients..
57. Sheng Ge; Meng-Yuan Ding; Zheng Zhang; Pan Lin; Jun-Feng Gao; Rui-Min Wang; Gao-Peng Sun; Keiji Iramina; Hui-Hua Deng; Yuan-Kui Yang; Yue Leng, Temporal-Spatial Features of Intention Understanding Based on EEG-fNIRS Bimodal Measurement, IEEE Access, 10.1109/ACCESS.2017.2723428, 5, 14245-14258, 2017.07, Understanding the actions of other people is a key component of social interaction. This paper used an electroencephalography and functional near infrared spectroscopy (EEG-fNIRS) bimodal system to investigate the temporal-spatial features of action intention understanding. We measured brain activation while participants observed three actions: 1) grasping a cup for drinking; 2) grasping a cup for moving; and 3) no meaningful intention. Analysis of EEG maximum standardized current density revealed that brain activation transitioned from the left to the right hemisphere. EEG-fNIRS source analysis results revealed that both the mirror neuron system and theory of mind network are involved in action intention understanding, and the extent to which these two systems are engaged appears to be determined by the clarity of the observed intention. These findings indicate that action intention understanding is a complex and dynamic process..
58. Kazuhisa Nojima, Keiji Iramina, Prediction of cortical excitability induced by 1 Hz rTMS, IEEJ Transactions on Electrical and Electronic Engineering, 10.1002/tee.22415, 12, 4, 601-607, 2017.07, The aim of this study was to develop a model that predicts the effects of repetitive transcranial magnetic stimulation (rTMS), allowing stimulation of parameters for individual subjects. Modulation of cortical excitability induced by rTMS can be evaluated through motor evoked potential (MEP) amplitude. We establish a model that can predict how the MEP amplitude is modulated by entering rTMS intensity and number of pulses. First, MEPs are measured under various rTMS conditions of stimulus intensity and number of pulses. Then, cluster analysis is performed to classify the subjects, as rTMS affects individuals differently. Finally, a predictive model is created by applying multiple regression analysis to the data from each cluster. As a result, subjects are classified into two groups. For Cluster A, the inhibitive effect of rTMS is difficult to induce and the facilitative effect is induced depending on the stimulus condition. Then, the average predictive error is 46.19%. For Cluster B, the inhibitive effect is strongly induced by rTMS, and the average error is 20.25%. In the model, for both clusters, about 90% of measurement data is in the predictive interval. This paper describes the development of our prediction model and its efficiency..
59. Ge Sheng, Ruimin Wang, Yue Leng, Haixian Wang, Pan Lin, Keiji Iramina, A Double-Partial Least-Squares Model for the Detection of Steady-State Visual Evoked Potentials, IEEE Journal of Biomedical and Health Informatics, 10.1109/JBHI.2016.2546311, 21, 4, 897-903, 2017.04.
60. Kaori Tamura, Takaaki Mizuba, Tsuyoshi Okamoto, Mayumi Matsufuji, Sachio Takashima, Keiji Iramina, Evaluation of cognitive function when hearing one's own name in patients with brain injuries in early developmental stages, Journal of Clinical Neurophysiology, 10.1097/WNP.0000000000000355, 34, 3, 254-260, 2017.01, Purpose: The level of residual cognitive function in patients with early brain injury is a key factor limiting rehabilitation and the quality of life. Although understanding residual function is necessary for appropriate rehabilitation, the extent of its effects on cognitive improvement remains unknown. This study evaluated cognitive function in patients with severe motor and intellectual disabilities after early brain injuries due to cerebral hemorrhage or periventricular leukomalacia. We focused on neural responses to hearing the subject's own name (SON). According to previous studies, differences in response to SON are associated with several types of cognitive dysfunction. Methods: We examined healthy subjects (aged 21.4 6 1.10 years; control) and patients with a previous brain injury (aged 13-27 years at the time of our analysis) resulting in periventricular leukomalacia or a cerebral hemorrhage during the perinatal period or childhood. We recorded EEG responses to the SON and to other Japanese words, obtaining EEG-evoked potentials with wavelet transformations. Results: Compared with healthy controls, beta power (not alpha power) revealed differences in response to SON by patients with brain injury, especially those with cerebral hemorrhage. Conclusions: We suggest that alpha and beta power differences reflect different cognitive functions and that the SON response reveals more than one process. Beta powers may reflect the intellectual disability of cognitive function in response to selfrelevant stimuli, especially in patients with cerebral hemorrhage. Meanwhile, alpha powers did not differ from those of the healthy controls, suggesting that the patients perhaps paid attention to their own names..
61. A. Sato, X. Liu, T. Torii, M. Iwahashi, K. Iramina, Modulation of motor cortex excitability by peripheral magnetic stimulation of different stimulus sites and frequencies, 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2016 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2016, 10.1109/EMBC.2016.7592196, 6413-6416, 2016.10, Peripheral stimulation is known to influence the state of cortical excitability. The purpose of this study is to investigate whether peripheral magnetic stimulation has similar effects on cortical excitability to transcranial magnetic stimulation (TMS). A magnetic stimulator with a flat figure-of-eight coil was used for both TMS, and peripheral magnetic stimulation applied to the bilateral forearms. TMS was performed on the left primary motor cortex to evaluate influence of the peripheral magnetic stimulation, and motor evoked potential (MEP) was measured from the right first dorsal interosseous. Peripheral magnetic stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz, to the stimulus sites on the right and left supination of the forearm. The effects of peripheral magnetic stimulation were evaluated by comparing the mean MEP amplitude elicited by TMS before and after peripheral magnetic stimulation. We found that cortical excitability varied according to the stimulation site and frequency of the peripheral magnetic stimulation. The inhibition of cortical excitability was observed following 1 Hz peripheral magnetic stimulation over the right forearm (p
62. Aya Sato, Xiangqun Liu, Tetsuya Torii, Masakuni Iwahashi, Keiji Iramina, Modulation of motor cortex excitability by peripheral magnetic stimulation of different stimulus sites and frequencies, Proceedings of 38th Engineering in Medicine and Biology Society EMBC2016, 6413-6416, 2016.08, Peripheral stimulation is known to influence the state of cortical excitability. The purpose of this study is to investigate whether peripheral magnetic stimulation has similar effects on cortical excitability to transcranial magnetic stimulation (TMS). A magnetic stimulator with a flat figure-of-eight coil was used for both TMS, and peripheral magnetic stimulation applied to the bilateral forearms. TMS was performed on the left primary motor cortex to evaluate influence of the peripheral magnetic stimulation, and motor evoked potential (MEP) was measured from the right first dorsal interosseous. Peripheral magnetic stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz, to the stimulus sites on the right and left supination of the forearm. The effects of peripheral magnetic stimulation were evaluated by comparing the mean MEP amplitude elicited by TMS before
and after peripheral magnetic stimulation. We found that cortical excitability varied according to the stimulation site and frequency of the peripheral magnetic stimulation. The inhibition of cortical excitability was observed following 1 Hz peripheral magnetic stimulation over the right forearm (p
63. Aya Sato, Xiangqun Liu, Tetsuya Torii, Masakuni Iwahashi, Keiji Iramina, Alteration of the Motor Cortex Excitability by Modulation of the Stimulus Parameter of Peripheral Stimulation, BME2016 in Vietnam, IFMBE Proceedings, 2016, 494-497, 2016.06, Transcranial magnetic stimulation (TMS) is known to elicit a conditioning effect on cortical excitability.
The purpose of this study was to investigate changes in cortical excitability induced by peripheral stimulation with differing frequency and stimulation site. A magnetic stimulator with a flat figure-eight coil was used for TMS and was performed on the left primary motor cortex. The electrical stimulation and magnetic stimulation were used in peripheral stimulation and the stimulus sites were the right and left supination of the forearm. Peripheral stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz. Alterations of cortical excitability induced by peripheral stimulation were evaluated by comparing the mean of the motor evoked potential amplitude elicited
by TMS each before and after peripheral stimulation. We found that cortical excitability varied according to the stimulation site and frequency in both the electrical and magnetic stimulation over the forearm. The inhibition of cortical excitability was observed in both 1 Hz electrical and magnetic stimulation over the right forearm. In contrast, the facilitation of cortical excitability was observed at 1 Hz electrical and magnetic stimulation over the left forearm, and it was confirmed for both the right and left forearms at 10 Hz electrical and magnetic stimulation. Moreover, regarding the alteration of cortical excitability induced by peripheral stimulation, it was
confirmed that magnetic stimulation has more the significant difference than electrical stimulation. We suggest that peripheral stimulation by electrical and magnetic stimulation have a similar effect to TMS, and can induce both facilitation and inhibition of cortical excitability. Moreover, in the case of peripheral stimulation of the same stimulus frequency, we expect that the magnetic stimulation has more the significant effect than electrical timulation to cortical excitability. .
64. Ruimin Wang, Keiji Iramina, Ge Sheng, An Improved Multiple LASSO Model for Steady-State Visual Evoked Potential Detection, BME2016 in Vietnam, IFMBE Proceedings, 2016, 457-460, 2016.06, Improving the classification accuracy in brain–computer interface (BCI) with a short data length is important
to increase the BCI system’s information transfer rate. Least absolute shrinkage and selection operator (LASSO) has been examined to be an effective way to detect the steady-state visual evoked potential (SSVEP) signals with a short time window. In this paper, an improved multiple LASSO model for SSVEP detection is proposed, which can process multichannel electroencephalogram (EEG) signals without electrode selection. EEG data from twelve healthy volunteers were used to test the improved multiple LASSO model. Compared with the traditional
LASSO model, the improved multiple LASSO model gives a significantly better performance with multichannel EEG data..
65. Takehito Hayami, Keiji Iramina, Xian Chen, Computer Simulation of Nerve Conduction Study of a Sural Nerve to Evaluate Human Peripheral Nervous System, BME2016 in Vietnam, IFMBE Proceedings, 2016, 461-464, 2016.06, Nerve conduction study is a test to examine the function of electric signal transmission at the trunk of a peripheral
nerve, which is an effective method for the diagnosis of diabetes to quantify the peripheral numbness and to evaluate the stage of this complication. In a routine test, the feature to measure in the electric potential waveform observed in this test is limited to the velocity and the amplitude of the peaks. To make the measurement more precise, the production process of the electric potential waveform should be observed carefully.
In this study, nerve conduction study of a sural nerve, which is the most popular for the patients with diabetes, was simulated in a computer using general cable equation and neuroanatomical data. As a result, the approximate electric potential waveform was reproduced, whereas the conduction velocity of the peaks .
66. Kurniawan Eka Permana, Keiji Iramina, Tsuyoshi Okamoto, Single Channel Electroencephalogram Measurement with Multi Scale Entropy Analysis for Evaluating Day Time Sleep, BME2016 in Vietnam, IFMBE Proceedings, 2016, 483-486, 2016.06, General method of evaluating sleep is to identify the stages of sleep from electroenchephalogram (EEG), electrooculogram (EOG) and electromyogram (EMG). Unfortunately, visual sleep scoring take a long time and very subjective. This causes developing of automatic sleep staging based on multi EEG, EOG and EMG. Recently, many researchers have developed automatic sleep stages based on single channel EEG to reduce the unnecessary number of wired. However, sleep stages cycle completed in ninety minutes. Short time or day time sleep experiment usually done in less than one hour and make it difficult to analysis with standard measurement.
The purpose of this research is developing an evaluation method by single channel EEG. This method works by measuring changes in amplitude power of EEG at a specific time of day time sleep. This different amplitude in term of complexity of EEG can be used to define as an index. Methods: We calculated EEG complexity with Multi Scale Entropy (MSE) for day time sleep experiment Results: The average entropy as the final result from the method could determine the EEG complexity of frequency power and have negative correlation with delta
wave. Based on this result, average entropy was used and had demonstrated a significant difference. Conclusion: MSE method could be useful to measure single channel EEG and significantly perform better understanding of day time sleep. .
67. Kaori Tamura, Takaaki Mizuba, Keiji Iramina, Hearing subjects own name induces the late positive component of event-related potential and beta power suppression, Brain Research, 10.1016/j.brainres.2016.01.032, 1635, 130-142, 2016.03, The neuronal response to hearing a subjects own name (SON) has been often investigated using event-related potential (ERP) or time-frequency analysis, but seldom by a combination of these methods. Using this combination of approaches would allow the relationship between memory processes engaged by SON and the neuronal responses to be studied in more detail. Thus, the present study used both ERP and time-frequency analysis to investigate memory process for SON by comparing the responses to SON and to unfamiliar names. Specifically, the SON condition was compared with two control conditions: Repeated unfamiliar names and singly presented unfamiliar names. This experimental design allowed us to determine the differences in memory processes between hearing onés own name and hearing unrelated but repeatedly heard names. ERP analysis showed that SON elicited a late positive component in parietal areas, while unfamiliar names elicited no positivity. Beta power suppression was observed in response to SON at 0.4-0.6 s after stimulus onset at right central sites, but not in response to unfamiliar names. These results are indicative of an involvement of episodic memory processes on hearing SON, which corresponds to the recognition of onés own name. Further, the ERP results suggest the presence of a "new" stimulus recognition process that is activated by singly presented unfamiliar names but not by repeated unfamiliar names..
68. Masaki Ono, Hiroki Furusho, Keiji Iramina, Analysis of the complexity of EEG during the short-term memory task, 8th Biomedical Engineering International Conference, BMEiCON 2015 BMEiCON 2015 - 8th Biomedical Engineering International Conference, 10.1109/BMEiCON.2015.7399576, 2016.02, By using fractal dimension and sample entropy, we investigated the complexity electroencephalogram (EEG) during an activity that uses working memory. We conduct a short-term memory test and a calculation task and analyzed 1.0s EEG data from 4 phases (resting, encoding, retrieval and calculation phase). As a result, fractal dimension analysis can reflect the activity of the working memory better than sample entropy analysis. Moreover, in order to investigate the relationship between the fractal dimension value and the power of theta band (4-8 Hz) in the frontal region, we conducted a correlation coefficient analysis. The result showed that increase of the power of theta band and decrease of fractal dimension value has relatively high correlation. In conclusion, the activity of working memory in frontal part may be able to be captured by fractal dimension analysis..
69. Kazuki Onikura, Keiji Iramina, Evaluation of a head movement artifact removal method for EEG considering real-time prosessing, 8th Biomedical Engineering International Conference, BMEiCON 2015 BMEiCON 2015 - 8th Biomedical Engineering International Conference, 10.1109/BMEiCON.2015.7399577, 2016.02, The present study proposes the method of removing head movement artifact for considering real-time processing and improving reliability of EEG under unconstrained measurement. In the proposed method, independent component analysis and high-pass filtering were used with a hybrid accelerometer, which was used for detecting components containing head movement artifact. To evaluate the proposed method, we measured EEG which included the artifact and P300 components. As a result, although EEG amplitude decreased, original P300 waveform appeared clearly. This result indicates that the proposed method is effective for removing head movement artifact while keeping EEG information..
70. Yuya Onitsuka, Yoshiyuki Shiotsuka, Keiji Iramina, The difference in the kinds of stimulations in CIT based on ERP, 8th Biomedical Engineering International Conference, BMEiCON 2015 BMEiCON 2015 - 8th Biomedical Engineering International Conference, 10.1109/BMEiCON.2015.7399578, 2016.02, The topic of our research is the detection of concealed information based on ERP (Event Related Potential). As a method to detect concealed information there is CIT (Concealed Information Test). CIT is used to detect intentionally concealed information, for example crime-related information, with subject's physiological response to presented stimuli. We used visually CIT based on P300 in the experiment. There are three kinds of stimuli in CIT. One is 'Probe', which is related to concealed information. The other is 'Irrelevant', which is not related with it but consists of same category as Probe (ex; place, time and so on). And the other is 'Target', which is for calling subject's attention to the experiment. In CIT, the subject's reaction to those presented stimuli are measured and compared with each other categories. If the reaction to Probe are different with one to Irrelevant the subject is considered as he knows Probe. Although Words are often used as stimulus in this kind of study, we assume that pictures are better as the stimulus in CIT. In this study, we investigated the difference between the word stimuli and picture stimuli in CIT. We use Japanese words or pictures as the stimulus and compare the amplitude of P300 as reaction to those stimuli. It is showed that picture stimuli are better than word stimuli for CIT..
71. Miki Kaneko, Yushiro Yamashita, Keiji Iramina, Quantitative Evaluation System of Soft Neurological Signs for Children with Attention Deficit Hyperactivity Disorder, Sensors, 10.3390/s16010116, 16, 1, 116-1-116-9, 2016.01, Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms of inattention, hyperactivity, and impulsivity. Soft neurological signs (SNS) are minor neurological abnormalities in motor performance, and are used as one evaluation method for neurodevelopmental delays in children with ADHD. Our aim is to establish a quantitative evaluation system for children with ADHD. We focused on the arm movement called pronation and supination, which is one such soft neurological sign. Thirty three children with ADHD aged 7–11 years (27 males, six females) and twenty five adults participants aged 21–29 years old (19 males, six females) participated in our experiments. Our results suggested that the pronation and supination function in children with ADHD has a tendency to lag behind that of typically developing children by several years. From these results, our system has a possibility to objectively evaluate the neurodevelopmental delay of children with ADHD..
72. Abdullah Basuki Rahmat, Keiji Iramina, Classification of multiclass EEG signal related to mental task using higuchi fractal dimension and 10-Statistic Parameters-Support Vector Machine, 35th IEEE Region 10 Conference, TENCON 2015 TENCON 2015 - 2015 IEEE Region 10 Conference, 10.1109/TENCON.2015.7372967, 2016.01, Nowadays, Not only the accuracy of a classification system but also a feature extraction method is an important matter in a Brain Computer Interface Application. In this paper, we investigated the multiclass classification of mental task using EEG signal. Higuchi Fractal Dimension and 10-Statistic Parameters were used as feature extraction method. The 10-statistic parameters are central tendency type that is, maximum value, minimum value, mean, standard deviation, median, mode, variance, first-quartile, third-quartile, interchange quartile. Multiclass Support Vector Machine with One-against-All strategy is applied to classify EEG signal related to the mental task. The result shows that the Multiclass SVM classifier with 1-against-All strategy using 10-Statistic Parameters has a higher accuracy when compared to Higuchi Fractal Dimension-SVM, Extreme Learning Machine, Back Propagation Neural Network, both of Support Vector Machine 1-versus-1 strategy and 1-versus-All strategy. The average accuracy ranging between 99.2% and 100% for 10-Statistic Parameters-SVM and HFD-SVM ranging from 60.22% to 91.91% were gained for five mental task classes..
73. Takehito Hayami, Keiji Iramina, Xian Chen, Estimation of clinical nerve conduction velocity using boundary element method, IEEJ Transactions on Electronics, Information and Systems, 10.1541/ieejeiss.136.1348, 136, 9, 1348-1349, 2016.01, Nerve conduction test is a noninvasive method to find some possible malfunction of a peripheral nerve to conduct action potentials between stimulation and observation points by observing the compound action potential after stimulation. To obtain the basic method to estimate the effect of composition and shape of a limb to the test results, compound action potential produced on the surface of a cylindrical limb was simulated using boundary element method. The produced potential wave had a typical shape of a compound action potential and conducted at rational velocity..
74. Shuji Mori, Keiji Iramina, Auditory brainstem responses to silent gaps in across-channel conditions, Acoustical Science and Technology, 10.1250/ast.37.79, 37, 2, 79-82, 2016, Auditory brainstem responses (ABRs) were measured to the onset of narrowband-noise trailing markers in the within-channel and across-channel conditions. ABRs have been measured in the context of within-channel gap detection, where gap thresholds defined by the presence of clearly peaked ABRs corresponded well to psychophysical gap thresholds of the same listeners. Ten male students participated in this study. No participants had any known hearing deficits or difficulty in listening to the stimuli used in the experiment, and they gave written informed consent prior to the experiment. There were five combinations of center frequencies of the leading and trailing markers. In the stimulus with no gap, the offset of the leading marker overlapped with the onset of the trailing marker, so that there was no amplitude decrement in the stimulus. For 800/800 and 1,600/800, the amplitudes remained low up to 1GT and jumped to a high level at 1.5 GT. For 800/1,600, the amplitude increased at 1 GT. For 800/3,200 and 3,200/800, the amplitudes increased at 0.5 GT but showed no significant increase thereafter..
75. Kaori Tamura, Chihiro Karube, Takaaki Mizuba, Mayumi Matsufuji, Sachio Takashima, Keiji Iramina, Phase-locked theta activity evoked in patients with severe motor and intellectual disabilities upon hearing own names, Brain & Development, 10.1016/j.braindev.2014.11.009, 37, 8, 764-772, 2015.11, Severe motor and intellectual disability (SMID) patients cannot express their feelings with language. Understanding what they are thinking about or how they feel is thus difficult. This study focused on brain responses to hearing their own names to clarify the situation in these patients.
We performed and analyzed electroencephalography (EEG) for six patients with SMID and eleven healthy subjects. All subjects were presented with auditory stimuli including calling the subject’s own name (SON) and reading words. EEG was analyzed by time–frequency analysis, event-related spectral perturbation (ERSP) to detect EEG power changes caused by EEG amplitude, and inter-trial coherence (ITC) to investigate phase-locked changes.
ERSP results from healthy subjects showed significant theta power increases as a specific response to SON. While we could not identify a similar pattern in the responses of patients with SMID, analysis of ITC revealed that theta phase-locked activity increased in response to SON not only in all healthy subjects, but also in four patients.
These results indicate that theta phase-locked activity in some patients with SMID was strongly associated with SON, as in healthy subjects. Our study suggests the existence of specific neural markers that signal an attentional shift in patients upon hearing SON..
76. Thanate Angsuwatanakul, Boonserm Kaewkamnerdpong, Keiji Iramina, Brain complexity analysis of functional near infrared spectroscopy for working memory study, Proceedings of 2015 8th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON.2015.7399531, 1-5, 2015.11, Working memory is an important brain functionfor memorizing information in everyday life. This study proposed an alternative approach for analyzing visual working memory based on brain complexity to identify brain state condition for memorizing new scene..
77. Kazuki Onikura, Keiji Iramina, Evaluation of a head movement artifact removal method for EEG considering real-time prosessing, Proceedings of 2015 8th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON.2015.7399531, 1-4, 2015.11, The present study proposes the method of removing head movement artifact for considering real-time processing and improving reliability of EEG under unconstrained measurement. In the proposed method, independent component analysis and high-pass filtering.
78. Masaki Ono, Hiroki Furusho, Keiji Iramina, Analysis of the complexity of EEG during the short-term memory task, Proceedings of 2015 8th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON.2015.7399531, 1-5, 2015.11, The present study proposes the method of removing head movement artifact for considering real-time processing and improving reliability of EEG under unconstrained measurement. In the proposed method, independent component analysis and high-pass filtering.
79. Yuya Onitsuka, Yoshiyuki Shiotsuka, Keiji Iramina, The difference in the kinds of stimulations in CIT based on ERP, Proceedings of 2015 8th Biomedical Engineering International Conference (BMEiCON), 10.1109/BMEiCON.2015.7399531, 1-5, 2015.11.
80. Fadilla Zennifa, Junko Ide, Yukio Noguchi, Keiji Iramina, Monitoring of cognitive state on mental retardation child using EEG, ECG and NIRS in four years study, 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2015 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2015, 10.1109/EMBC.2015.7319908, 6610-6613, 2015.11, In this study, a monitoring system of cognitive state in usual behavior without restraint using wireless EEG, ECG and NIRS on developmental disorder children such as mental retardation was developed. By using this system we would like to investigate the education training effect on cognitive state in a mental retardation child in four years. The aim of special education is to make adaptations, accommodations and modification that allow a child with a mental retardation to succeed in classroom. This education training separated into two systems, resting state and studying state. After the measurement, we calculated the EEG power spectrum of alpha, theta bands and the low frequency power (LF), high frequency power (HF), and LH/HF value from the RR interval in ECG. At the same time we calculated the changes in concentration of oxyhemoglobin ([oxy-Hb]). The result in studying state showed theta power is lower than beta power in study state in the other hand beta power is lower than theta power in resting state From LF/HF activity we could know that sympathetic activity is increasing and from the result that has obtained from ECG, the parasympathetic activity is decreasing the time. NIRS showed the increasing in study states and decreasing in resting states at Fp2 area from oxyhemoglobin analysis..
81. Miki Kaneko, Yushiro Yamashita, Osamu Inomoto, Keiji Iramina, Soft neurological signs in childhood by measurement of arm movements using acceleration and angular velocity sensors, Sensors (Switzerland), 10.3390/s151025793, 15, 10, 25793-25808, 2015.10, Soft neurological signs (SNS) are evident in the motor performance of children and disappear as the child grows up. Therefore SNS are used as criteria for evaluating age-appropriate development of neurological function. The aim of this study was to quantify SNS during arm movement in childhood. In this study, we focused on pronation and supination, which are arm movements included in the SNS examination. Two hundred and twenty-three typically developing children aged 4–12 years (107 boys, 116 girls) and 18 adults aged 21–26 years (16 males, two females) participated in the experiment. To quantify SNS during pronation and supination, we calculated several evaluation index scores: bimanual symmetry, compliance, postural stability, motor speed and mirror movement. These index scores were evaluated using data obtained from sensors attached to the participants’ hands and elbows. Each score increased as age increased. Results obtained using our system showed developmental changes that were consistent with criteria for SNS. We were able to successfully quantify SNS during pronation and supination. These results indicate that it may be possible to use our system as quantitative criteria for evaluating development of neurological function..
82. Zennifa Fadilla, Junko Ide, Yukihiro Noguchi, Keiji Iramina, Monitoring of Cognitive State on Mental Retardation Child using EEG, ECG and NIRS in Four Years Study, Proceedings of 37th Engineering in Medicine and Biology Society EMBC2015, 6610-6613, 2015.08.
83. Aya Sato, Tetsuya Torii, Masakuni Iwahashi, Keiji Iramina, Basic study on the influence of inhibition induced by the magnetic stimulation on the peripheral nerve, Journal of Applied Physics, 10.1063/1.4908303, 117, 17, 17B303-1-17B303-4, 2015.05, The purpose of this study is to analyze the inhibition mechanism of magnetic stimulation on motor function. A magnetic stimulator with a flat figure-eight coil was used to stimulate the peripheral nerve of the antebrachium. The intensity of magnetic stimulation was 0.8 T, and the stimulation frequency was 1 Hz. The amplitudes of the motor-evoked potentials (MEPs) at the abductor pollicis brevis muscle and first dorsal interosseous muscle were used to evaluate the effects of magnetic stimulation. The effects of magnetic stimulation were evaluated by analyzing the MEP amplitude before and after magnetic stimulation to the primary motor cortex. The results showed that MEP amplitude after magnetic stimulation compared with before magnetic stimulation decreased. Because there were individual differences in MEP amplitude induced by magnetic stimulation, the MEP amplitude after stimulation was normalized by the amplitude of each participant before stimulation. The MEP amplitude after stimulation decreased by approximately 58% (p
84. Ning Zhao, Xian Chen, Keiji Iramina, A 3D COUPLED MATHEMATICAL MODEL FOR THE GROWTH OF AVASCULAR SOLID TUMOR, Journal of Mechanics in Medicine and Biology, 10.1142/S0219519415500244, 15, 1, 1550024-1550024, 2015.03, We develop a coupled mathematical model of avascular tumor growth based on porous media mechanics. This comprises of the migration of tumor cells (TCs), the degradation of extracellular matrix (ECM), the transport of matrix-degrading enzymes (MDEs), the seepage of tissue fluid and the supplement and consumption of oxygen. The simulation that a solid tumor grows in the micro-environment composed of the pre-existing capillaries and the surrounding tissues, and the specific property of varying porosity with the growth of TCs in a tumor micro-environment are taken into account. We propose functional coefficients for fluid seepage and oxygen diffusion, and incorporate the convection–diffusion of oxygen and the convection of MDEs. From this modified model the main findings include: first, a solid tumor originating in the inlet region undergoes necrosis in the outlet region because of a low supply of oxygen, while a solid tumor originating in the outlet region undergoes necrosis at the primary site because of overconsumption of oxygen; second, tumors further from capillaries grow faster than tumors close to adjacent capillaries; third, the pre-existing capillaries cause some impact to the transport of those chemical factors involved in tumor growth, and further affect tumor migration and necrosis.
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85. Kazuki Onikura, Yoshinori Katayama, Keiji Iramina, Evaluation of a Method of Removing Head Movement Artifact from EEG by Independent Component Analysis and Filtering, Advanced Biomedical Engineering, 10.14326/abe.4.67, 4, 1, 67-72, 2015.03, Artifacts that contaminate electroencephalography (EEG) signals make it difcult to analyze EEG. The aim of this study was to removal artifacts on EEG, specially those caused by motion, to measure EEG in unconstrained situations. In a previous study, head movements were detected by an accelerometer, and motion artifact components were separated from the recorded EEG by independent component analysis (ICA). This method is effective for reducing the effect of artifacts, but has a risk that EEG components are also removed. In this paper, we introduce an improved artifact removal method based on ICA and ltering. EEG were decomposed by ICA, and a Pearson’s correlation coefcient was calculated between each independent component and each hybrid accelerometer value to distinguish artifact components. Artifact components were then high-pass ltered. In this study, subjects were instructed to move their heads randomly, while keeping their eyes closed. The previous method was adapted using 1, 2, 3, 5 and 10 s to nd the most suitable epoch to minimize the mean absolute amplitude of the cleaned EEG. Then, using this epoch, the proposed method was compared with the previous method by frequency analysis. Low frequency power (0.1–3 Hz) was normalized to unity because most power caused by motion artifacts exists in the low power band. If the normalized theta (4–8 Hz), alpha (8–13 Hz) and beta (13–40 Hz) powers of cleaned EEG are higher than that of raw EEG, this indicates that the effect of motion artifacts is small and EEG components are retained. The results obtained from theta and alpha power comparison showed that the proposed method performed better than the previous method. This result suggests that the proposed artifact removal method is more effective to reduce the effect of artifacts while retaining the EEG components..
86. Ning Zhao, Keiji Iramina, Numerical simulation of effect of convection-diffusion on oxygen transport in microcirculation, Applied Mathematics and Mechanics, 10.1007/s10483-015-1908-7, 36, 2, 179-200, 2015.02, The entire process of oxygen transport in microcirculation by developing a 3D porous media model is calculated numerically with coupled solid deformation-fluid seepage-convection and diffusion . The principal novelty of the model is that it takes into account volumetric deformation of both capillary and tissues resulting from capillary fluctuation. How solid deformation, fluid seepage, and convection-diffusion combine to affect
oxygen transport is examined quantitatively: (1) Solid deformation is more significant in the middle of capillary, where the maximum value of volumetric deformation reaches about 0.5%. (2) Solid deformation has positive influence on the tissue fluid so that it flows more uniformly and causes oxygen to be transported more uniformly, and eventually impacts oxygen concentration by 0.1%–0.5%. (3) Convection-diffusion coupled deformation and seepage has a maximum (16%) and average (3%) increase in oxygen concentration, compared with pure molecular diffusion. Its more significant role is to allow oxygen to be transported more evenly. .
87. Ning Zhao, Keiji Iramina, A mathematical coupled model of oxygen transport in the microcirculation: The effect of convection-diffusion on oxygen transport, Journal of Mechanics in Medicine and Biology, 10.1142/S0219519415500037, 15, 1, 1550003-1-155003-26, 2015.01, This paper is aimed at examining the effect of convection–diffusion on oxygen transport at the micro-level. A coupled model of the convection–diffusion and molecular diffusion of oxygen is developed, and the solid deformation resulting from capillary fluctuations and the seepage of tissue fluid are incorporated into this model. The results indicate that (1) the oxygen concentration calculated from this coupled model is higher than that given by molecular diffusion
models, both within the capillaries and tissue (maximum difference of 16%); (2) convection–diffusion has the greatest effect in tissue surrounding the iddle of the capillary, and enhances the amount of oxygen transported to cells far from the oxygen source; (3) larger permeability coefficients or smaller diffusion coefficients produce a more obvious convection–diffusion effect; (4) a counter-current flow occurs near the inlet and outlet ends of the capillary. This model also provides a foundation for the study of how oxygen affects tumor growth..
88. N. Zhao, Keiji Iramina, Numerical simulation of effect of convection-diffusion on oxygen transport in microcirculation, Applied Mathematics and Mechanics (English Edition), 10.1007/s10483-015-1908-7, 36, 2, 179-200, 2015.01, The entire process of oxygen transport in microcirculation by developing a 3D porous media model is calculated numerically with coupled solid deformation-fluid seepage-convection and diffusion. The principal novelty of the model is that it takes into account volumetric deformation of both capillary and tissues resulting from capillary fluctuation. How solid deformation, fluid seepage, and convection-diffusion combine to affect oxygen transport is examined quantitatively: (1) Solid deformation is more significant in the middle of capillary, where the maximum value of volumetric deformation reaches about 0.5%. (2) Solid deformation has positive influence on the tissue fluid so that it flows more uniformly and causes oxygen to be transported more uniformly, and eventually impacts oxygen concentration by 0.1%–0.5%. (3) Convection-diffusion coupled deformation and seepage has a maximum (16%) and average (3%) increase in oxygen concentration, compared with pure molecular diffusion. Its more significant role is to allow oxygen to be transported more evenly..
89. Thanate Angsuwatanakul, Keiji Iramina, Boonserm Kaewkamnerdpong, Multi-scale sample entropy as a feature for working memory study, IEEE Conference Publication, Biomedical Engineering International Conference (BMEiCON), 2014 , 10.1109/BMEiCON.2014.7017446, 1-5, 2014.11, Toward the understanding of how human brains work so that we could manage to effectively improve the conditions of neurological disorders or even enhance the cognitive performance, working memory study is of interest. Multi-scale sample entropy has been used to analyze the complexity of biomedical data. This study aims to investigate the potential of using multi-scale sample entropy as a feature for characterizing memory. We applied complexity analysis on EEG data recorded during a cognitive experiment targeting working memory through visual stimuli. The results revealed the distinctive sample entropy for various memory cases in prefrontal area. This indicated the potential of using multi-scale sample entropy for characterizing memory..
90. Tesuya Torii, Aya Sato, Masakuni Iwahashi, Keiji Iramina, Change of Cognition Effects by Impact of the Transcranial Magnetic Stimulation, IEEE Transactions on Magnetics, 10.1109/TMAG.2014.2323071, 50, 11, 5101104, 2014.11, The purpose of this paper is to investigate the effects of sub- or supra-threshold low-frequency repetitive transcranial magnetic stimulation (rTMS) on cognitive function. The magnetic stimulation was delivered at 1 Hz to the left supramarginal gyrus, which is considered to be the area of origin of the P300 event-related potential component. The intensity of magnetic stimulation was 80% or 120% of motor threshold, and 100 magnetic pulses were applied. The auditory oddball task, consisting of tone burst waves, was used to elicit P300 before and shortly after magnetic stimulation. We found that P300 latency depended on the intensity of the 1 Hz magnetic stimulation. With subthreshold rTMS, P300 latency was significantly shortened compared with before magnetic stimulation by around 10 ms (Cz: p
91. Ruimin Wang, Yue Leng, Yuankui Yang, Wen Wu, Keiji Iramina, Sheng Ge, A partial least squares-based stimulus frequency recognition model for steady-state visual evoked potentials detection, Proceedings of 7th International Conference on Biomedical Ngineering and Informatics(BMEI), 10.1109/BMEI.2014.7002863, 699-703, 2014.10, With shorter calibration times and higher information transfer rates, steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) have been studied most activity in recent years. Target identification is the ongoing core task in BCI researches, and plays a significant role in practical applications. In order to improve the performance of SSVEP-based BCI system, we proposed a partial least squares (PLS)-based stimulus frequency recognition model for SSVEP detection. Moreover, we compared the proposed method with canonical correlation analysis (CCA) and least absolute shrinkage and selection operator (LASSO) method, respectively. The experiment results showed that PLS can not only extract the SSVEP features effectively, but also can increase the classification accuracies of SSVEP-based BCI systems..
92. Fadilla Zennifa, Fitrilina, Husnil Kamil,, Keiji Iramina, Prototype early warning system for heart disease detection using Android application, Proceedings of The 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC’14), 10.1109/EMBC.2014.6944369 , 3468-3471, 2014.08, Heart Disease affects approximately 70 million people worldwide where most people do not even know the symptoms. This research examines the prototype of early warning system for heart disease by android application. It aims to facilitate users to early detect heart disease which can be used independently. To build the application in android phone, variable centered intelligence rule system (VCIRS) as decision makers and pulse sensor - Arduino as heart rate detector were
applied in this study. Moreover, in Arduino, the heart rate will become an input for symptoms in Android Application. The output of this system is the conclusion statement of users diagnosed with either coronary heart disease, hypertension heart disease, rheumatic heart disease or do not get any kind of heart disease. The result of diagnosis followed by analysis of the
value of usage variable rate (VUR) rule usage rate (RUR) and node usage rate (NUR) that shows the value of the rule that will increase when the symptoms frequently appear. This application was compared with the medical analysis from 35 cases of heart disease and it showed concordance between diagnosis from android application and expert diagnosis of the doctors..
93. Ruimin Wang, Wen Wu, Keiji Iramina, Sheng Ge, The combination of CCA and PSDA detection methods in a SSVEP-BCI system, Proceedings of 11th World Congress on Intelligent Control and Automation (WCICA), 10.1109/WCICA.2014.7053101, 2424-2427, 2014.07, In recent years, based on the steady-state visual evoked potential (SSVEP) brain-computer interfaces (BCIs) have generated significant interest, due to their shorter calibration times and higher information transfer rates. Target identification is the core signal processing task in BCIs. Power spectral density analysis (PSDA) and canonical correlation analysis (CCA) are the most popular and widely used classification methods in SSVEP-BCI systems. In this paper, we first combined these two methods for detecting the SSVEP signals. Moreover, we compared the proposed method with PSDA, CCA method, respectively. The results showed that the proposed method can improve the accuracy and the transfer rate of BCIs..
94. Aya Sato, Tetsuya Torii, Masakuni Iwahashi, Yuji Ito, Keiji Iramina, Modulation of amplitude and latency of motor evoked potential by direction of transcranial magnetic stimulation, Journal of Applied Physics, 10.1063/1.4862716, 115, 17, 17E304 -17E304-3, 2014.05, The present study analyzed the effects of monophasic magnetic stimulation to the motor cortex. The effects of magnetic stimulation were evaluated by analyzing the motor evoked potentials (MEPs). The amplitude and latency of MEPs on the abductor pollicis brevis muscle were used to evaluate the effects of repetitive magnetic stimulation. A figure eight-shaped flat coil was used to stimulate the region over the primary motor cortex. The intensity of magnetic stimulation was 120% of the resting motor threshold, and the frequency of magnetic stimulation was 0.1 Hz. In addition, the direction of the current in the brain was posterior-anterior (PA) or anterior-posterior (AP). The latency of MEP was compared with PA and AP on initial magnetic stimulation. The results demonstrated that a stimulus in the AP direction increased the latency of the MEP by approximately 2.5 ms. MEP amplitude was also compared with PA and AP during 60 magnetic stimulations. The results showed that a stimulus in the PA direction gradually increased the amplitude of the MEP. However, a stimulus in the AP direction did not modulate the MEP amplitude. The average MEP amplitude induced from every 10 magnetic pulses was normalized by the average amplitude of the first 10 stimuli. These results demonstrated that the normalized MEP amplitude increased up to approximately 150%. In terms of pyramidal neuron indirect waves (I waves), magnetic stimulation inducing current flowing backward to the anterior preferentially elicited an I1 wave, and current flowing forward to the posterior elicited an I3 wave. It has been reported that the latency of the I3 wave is approximately 2.5 ms longer than the I1 wave elicitation, so the resulting difference in latency may be caused by this phenomenon. It has also been reported that there is no alteration of MEP amplitude at a frequency of 0.1 Hz. However, this study suggested that the modulation of MEP amplitude depends on stimulation strength - nd stimulation direction..
95. Kazuhisa Nojima, Yoshinori Katayama, Keiji Iramina, rTMS and tDCS effects on the power and ERD of mu wave, IEEJ Transactions on Fundamentals and Materials, 133, 9, 478-483, 2013.09.
96. Kaori Tamura, Chihiro Karube, Takaaki Mizuba, Mayumi Matsufuji, Sachio Takashima, Keiji Iramina, Measurement of brain activity responded by subjects'own name using EEG, Proceedings of The 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC’13), 10.1109/EMBC.2013.6611271 , 7412 -7415, 2013.07, Sever motor and intellectual disabilities (SMID) patients can't express their feelings with languages. That's why it is important to measure and analyze their brain activity. In this study, we tried to investigate the brain response to hearing subject's own name of healthy people and one patient with SMID by analyzing EEG. The results of time frequency analysis showed the inter trial coherence of a patient with SMID at theta oscillation was higher in response to SON specifically. On the other hand, that of healthy subjects was not so different with that in response to control condition. These results might reflect of the difference of lexical semantic process between the patient and healthy subjects..
97. Kazuhisa Nojima, Yoshinori Katayama, Keiji Iramina, Predicting rTMS effect for deciding stimulation parameters, Proceedings of The 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC’13), 10.1109/EMBC.2013.6611011, 6369 -6372, 2013.07, Repetitive transcranial magnetic stimulation (rTMS) is used in the medical field to modulate cortical excitability. However, when applied in this setting, rTMS stimulation parameters are not usually decided objectively. The aim of this study is to make a model that predicts the rTMS effect, allowing stimulation parameters (intensity and pulse number) to be easily determined before use. First, we investigated the relationship between stimulation condition and rTMS outcome. rTMS delivered at 1 Hz was applied with stimulation intensities of 85%, 100%, or 115% resting motor threshold (RMT) over the primary motor cortex in the left hemisphere. Motor-evoked potentials (MEPs) were measured before rTMS and after every 200 rTMS pulses. Eighteen hundred pulses were applied for each stimulation condition. Results showed that more pulses and stronger intensities lead to a larger decrease in MEP amplitude. An initial prediction model was then made by applying multiple regression analysis over the experimental data. We then adjusted the model depending on the size of the initial MEP amplitude before rTMS, and confirmed the improvement..
98. Aya Sato, Tesuya Torii, Yuko Nakahara, Masakuni Iwahashi, Keiji Iramina, The impact of rTMS over the dorsolateral prefrontal cortex on cognitive processing, Proceedings of The 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC’13), 10.1109/EMBC.2013.6609919 , 1988-1991, 2013.07, The purpose of the present study was to use event-related potentials (ERP) to clarify the effect of magnetic stimulation on cognitive processing. A figure eight-shaped flat repetitive transcranial magnetic stimulation (rTMS) coil was used to stimulate either the region over the left or the right dorsolateral prefrontal cortex, which is considered to be the origin of the P300 component. Stimulus frequencies were 1.00, 0.75 and 0.50 Hz rTMS. The strength of the magnetic stimulation was set at 80% of the motor threshold for each participant. The auditory oddball task was used to elicit P300s before and shortly after rTMS, and comprised a sequence of sounds containing standard (1 kHz pure tone, 80% of trials) and deviant (2 kHz pure tone, 20% of trials) stimuli. We found that a 1.00 Hz rTMS pulse train over the left dorsolateral prefrontal cortex increased P300 latencies by 8.50 ms at Fz, 12.85 ms at Cz, and 11.25 ms at Pz. In contrast, neither 0.75 and 0.50 Hz rTMS pulse trains over the left dorsolateral prefrontal cortex nor 1.00, 0.75 and 0.50 Hz rTMS pulse trains over the right dorsolateral prefrontal cortex altered P300 latencies. These results indicate that rTMS frequency affects cognitive processing. Thus, we suggest that the effects of rTMS vary according to the activity of excitatory and inhibitory neurons in the cerebral cortex..
99. Fumiyoshi Matsusaki, Yoshinori Katayama, Keiji Iramina, Influence of TMS Coil Orientation in the Simulation of Neuronal Excitation by TMS Using an Axon Model and Cerebral Cortex Model, Advanced Biomedical Engineering, DN/JST.JSTAGE/abe/1.55, 1, 1, 55-59, 2013.06, Transcranial magnetic stimulation (TMS) allows non-invasive and painless stimulation of local cerebral nerves using eddy current generated by electromagnetic induction with a TMS coil. Although TMS is used in various fields, which area of the brain is stimulated is not known because of the complicated structure of the organ. In this study, we simulated neuronal excitement by TMS using the finite element method. First, we designed a brain sulcus model consisting of cerebrospinal fluid, gray matter and white matter, using 0.5 mm cube elements. To improve calculation accuracy, cube element size was set to 0.5/3 mm only in regions near the boundary surface. Second, we applied TMS stimulation to the model in different conditions. We used coil radii of 10, 20, 30 and 40 mm, and coil orientation at 0°, 30°, 45°, 60° and 90°, which is defined as the angle between the orientation of the electric field and the axon. Finally, we calculated the membrane potential and compared the results obtained under different conditions. We found that membrane potential changed rapidly at the white matter and gray matter interface when the coil radius was over 20 mm and coil orientation was within 60° between the orientation of the electric field and the axon. These results provide useful information on appropriate TMS parameters for effective stimulation of target area in the brain. .
100. Dilok Puanhvuan, Kazuhisa Nojima, Yodchanan Wongsawat, Keiji Iramina, Effects of Repetitive Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation on PosteriorAlpha Wave, IEEJ Transactions on Electrical and Electronic Engineering, 10.1002/tee.21849, 8, 3, 263-268, 2013.05, Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are promising tools for painless cortical stimulation. It has been widely use in the clinical field for treating some diseases. In addition, it can also be used for investigating the brain function, e.g. both rTMS and tDCS are possible to be used to inhibit or excite the human brain activities. In biomedical research, one of the most interesting brain activities would be the alpha wave, the oscillation in the range of 8-13 Hz acquired by the non-invasive electroencephalography (EEG). However, the rTMS and tDCS effects on posterior EEG alpha wave remain unclear. This study aimed to investigate the effect of rTMS and tDCS on the posterior alpha wave. The transcranial stimulation effects was observed by analyzing a measured EEG at the occipital area during eyes opened and eyes closed phases, before and after stimulation. The EEG alpha power and alpha coherence were calculated and analyzed in terms of the ratio between eyes closed and eyes opened periods. The results revealed that alpha power ratio at the individual alpha frequency (IAF) significantly increased after the 1Hz rTMS and cathodal tDCS (inhibited condition) and slightly decreased after the anodal tDCS (excited condition) compared to the control and sham condition. The results also showed that there was a significant difference between the inhibited and excited conditions. Similarities were observed in the patterns of alpha coherence ratio and alpha power changes, with respective increased in the rTMS and cathodal tDCS conditions and a decreased in the anodal tDCS condition, but only when comparing across hemispheres (O1-O2 and P3-P4). It could be summarized that the EEG alpha wave could be influenced by the transcranial stimulations. The inhibition and facilitation conditions resulted in the opposite change..
101. Kaori Tamura, Chihiro Karube, Takaaki Mizuba, Keiji Iramina, ERP and time frequency analysis of response to subject's own name , Biomedical Engineering International Conference (BMEiCON), 2012 , 10.1109/BMEiCon.2012.6465434 , 1-4, 2012.12, Hearing one's own name plays an important roll in external communications and internal cognition within our minds. Though hearing one's own name well has been studied, the relationship between hearing one's own name and self-awareness is not understood. In this study, we focused on brain responses to hearing one's own name. In order to assess the pattern of ERP and the power of EEG frequency during hearing one's own name, we used a passive oddball paradigm that included the subject's own name (SON). The grand average ERP showed that mismatch negativity and novelty p300 were elicited by SON. Time frequency analysis revealed that theta power and beta power were increased around 400-600 ms after stimulus by SON..
102. Tesuya Torii, Aya Sato, Masakuni Iwahashi, Keiji Iramina, Frequency Dependence of P300 Latency by Low-Frequency Repetitive Transcranial Magnetic Stimulation, IEEE Transactions on Magnetics, 10.1109/TMAG.2012.2201251 , 48, 11, 2865-2868, 2012.11, The aimof this study was to investigate the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. The latency of the P300 component of the event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS on brain activity.We investigated the effects of rTMS on P300 latencies by stimulating the supramarginal gyrus (SMG), which is considered to be the area of origin of the P300. As the frequency-dependence of low-frequency rTMS has not been previously investigated in detail, we evaluated the effects of rTMS at frequencies of 1, 0.75 or 0.5 Hz on P300 latencies. The odd-ball task was used to elicit P300s before and shortly after the scalp was stimulated by rTMS. Electroencephalography recordings were measured at the Fz, Cz and Pz electrodes, which were based on the international 10–20 electrode system. We found that 1, 0.75 and 0.5 Hz rTMS affected P300 latencies. 1 Hz rTMS of the left SMG shortened P300 latencies by approximately 25 ms at the Cz compared with the P300 latencies before rTMS. 0.5
Hz rTMS of the left SMG lengthened P300 latencies by approximately 20 ms at the Cz compared with the P300 latencies before rTMS. In contrast, 0.75 Hz rTMS of the left SMG did not affect P300 latencies. These results demonstrate that P300 latencies vary according to the frequency of rTMS. .
103. Tesuya Torii, Aya Sato, Masakuni Iwahashi, Keiji Iramina, Transition of After Effect on P300 by Short-Term rTMS to Prefrontal Cortex, IEEE Transactions on Magnetics, 10.1109/TMAG.2012.2204432 , 48, 11, 2873-2876, 2012.11, In the present study, we analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. The latency of the P300 component of the event-related potential (ERP) was used to evaluate the effects of low-frequency rTMS following stimulation of the dorsolateral prefrontal cortex (DLPFC), which is an area considered to be related to the generation of the P300. In addition, prolonged stimulation effects on the P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate the left or right DLPFC, and the intensity of magnetic stimulation was 80% of the motor threshold. A total of 100 magnetic pulses were applied for the rTMS. The effects of stimulation at frequencies of 0.5 or 1 Hz were determined. An odd-ball task was performed before and 5, 10, and 15 minutes after rTMS to measure the effects of rTMS on the P300. Electroencephalography (EEG) was measured at the Fz, Cz and Pz electrodes using the international 10–20 electrode system. We found that 0.5 and 1 Hz rTMS produced different effects on P300 latencies. 1 Hz stimulation of the left DLPFC lengthened P300 latencies by approximately 20 ms at the Cz, which lasted up to 15
minutes post-rTMS. In contrast, 0.5 Hz rTMS stimulation of the left DLPFC and 0.5 and 1 Hz rTMS stimulation to right DLPFC had no significant effects on P300 latencies. These results demonstrate that the effects of rTMS on the P300 latency depend on the frequency of stimulant and the area stimulated. Furthermore, we have determined the duration of this effect of low-frequency and short-term rTMS..
104. Miki kaneko, Hiroshi Okui, Go Hirakawa, HIroshi Ishinishi, Yoshinori Katayama, Keiji Iramina, Aging Curve of Neuromotor Function by Pronation and Supination of Forearms using Three-dimensional Wireless Acceleration and Angular Velocity Sensors, Procdeedings of 34th Annual International Conference of the EMBS San Diego, California USA, 28 August - 1 September, 2012, 4376-4379, 2012.08, We have developed an evaluation system for pronation and supination of forearms. The motion of pronation and supination of the forearm is used as a diagnosis method of developmental disability, etc. However, this diagnosis method has a demerit in which diagnosis results between doctors are not consistent. It is hoped that a more quantitative and simple evaluation method is established. Moreover it is hoped a diagnostic criteria obtained from healthy subjects can be established to diagnose developmental disorder patients. We developed a simple and portable evaluation system for pronation
and supination of forearms. Three-dimensional wireless acceleration and angular velocity sensors are used for this
system. In this study, pronation and supination of forearms of 570 subjects (subjects aged 6-12, 21-100) were examined. We could obtain aging curves in the neuromotor function of pronation and supination. These aging curves obtained by our
developed system, has the potential to become diagnostic criteria for a developmental disability, etc..
105. Tesuya Torii, Aya Sato, Masakuni Iwahashi, Yuji Ito, Keiji Iramina , Time-Dependent Effects of Low-Frequency Repetitive Transcranial Magnetic Stimulation of the Supramarginal Gyrus, Procdeedings of 34th Annual International Conference of the EMBS San Diego, California USA, 28 August - 1 September, 2012, 3372-3375, 2012.08, In this paper, we report our studies of the effects of stimulating the bilateral supramarginal gyrus (SMG) with low-frequency transcranial magnetic stimulation (rTMS) or short-term rTMS on brain excitability in humans. We analyzed the effects of various durations of stimulation on P300 latencies of the event-related potential (ERP). Magnetic pulses were
delivered using a figure-eight flat coil. The intensity of rTMS was set to 80 % of the subject’s motor threshold. In each round of rTMS, 100 magnetic pulses were applied over the scalp at frequencies of 1.00, 0.75, and 0.50 Hz. ERPs were measured prior to magnetic stimulation as a control. The effects of magnetic stimulation were then determined by measuring its effects on P300 latencies elicited by an odd-ball task. These latencies were measured before and 0, 5, 10, and 15 min after the magnetic stimulation. 1.00 Hz low-frequency rTMS of the left SMG decreased P300 latencies for approximately 10 min. In contrast, 0.50 Hz rTMS of the left SMG resulted in delayed P300 latencies for approximately 15 min. We furthermore found that 0.75 Hz rTMS of the left SMG and 1.00, 0.75 and 0.5 Hz rTMS of the right SMG did not affect P300 latencies. These results suggest that the duration of the effects of rTMS depend on the frequency of stimulation..
106. Mingdi Xu, Johan Lauwereyns, Keiji Iramina, Dissociation of category versus item priming in face processing: an event-related potential study , Cognitive Neurodynamics , 10.1007/s11571-011-9185-6, 6, 2, 155-167, 2012.04, The underlying specificity of visual object categorization and discrimination can be elucidated by studying different types of repetition priming. Here we focused on this issue in face processing. We investigated category priming (i.e. the prime and target stimuli represent different exemplars of the same object category) and item priming (i.e. the prime and target stimuli are exactly the same image), using an immediate repetition paradigm. Twenty-three subjects were asked to respond as fast and accurately as possible to categorize whether the target stimulus was a face or a building image, but to ignore the prime stimulus. We recorded event-related potentials (ERPs) and reaction times (RTs) simultaneously. The RT data showed significant effects of category priming in both face trials and building trials, as well as a significant effect of item priming in face trials. With respect to the ERPs, in face trials, no priming effect was observed at the P100 stage, whereas a category priming effect emerged at the N170 stage, and an item priming effect at the P200 stage. In contrast, in building trials, priming effects occurred already at the P100 stage. Our results indicated that distinct neural mechanisms underlie separable kinds of immediate repetition priming in face processing.
.
107. Tetsuya Torii, Aya Sato, Masakuni Iwahashi, and Keiji Iramina, Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300, Journal of Applied Physics, 10.1063/1.3676204 , 111, 07B319, 2012.03, The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10–20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5–1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS..
108. Tetsuya Torii, Aya Sato, Y Masada, Masakuni Iwahashi, Keiji Iramina, Effect of the short-term magnetic stimulation by rTMS on P300 latency, Proceedings in Biomedical Engineering International Conference (BMEiCON 2011) , 10.1109/BMEiCon.2012.6171988 , 7-10, 2012.01, The purpose of this study is to investigate the effect of P300 latency in case of magnetic stimulation to human brain by rTMS. This stimulation is 100 pulses with 1 Hz or 0.5 Hz low-frequency. The stimulation points are left-right SMG and left-right DLPFC. In case of 1 Hz magnetic stimulation to left SMG, P300 latency after the magnetic stimulation was shorter than P300 latency before the magnetic stimulation. In case of 1 Hz low-frequency magnetic stimulation to left DLPFC, P300 latency after the magnetic stimulation was later than before the magnetic stimulation. In case of 0.5 Hz low-frequency magnetic stimulation to left SMG, the delay of P300 latency was observed. Generally, in the low-frequency magnetic stimulation equal to or less than 1 Hz, the brain activity is inhibited by stimulating the brain. The activity of left SMG is excited at 1 Hz and inhibited at 0.5 Hz. As this reason, at first, in this study, the frequency of the magnetic stimulation is just 1 Hz and this frequency is border of low-frequency and high-frequency. Secondarily, the sensitivity for the magnetic stimulation varies by parts of brain. Therefore, this study suggests that left SMG is activated by the short-term magnetic stimulation using rTMS (1 Hz, 100 pulses). .
109. Kazuhisa Nojima, Ge Sheng, Yoshinori Katayama, Keiji Iramina, Relationship between pulse number of rTMS and inter reversal time of perceptual reversal , 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) , 10.1109/IEMBS.2011.6091999 , 8106 - 8109 , 2011.08, The aim of this study is to investigate the stimulus parameter which affects the repetitive Transcranial Magnetic Stimulation (rTMS) effect. It is said that the condition under 1Hz rTMS induces the inhibition effect. On the other hand, the condition over 1Hz rTMS induces the facilitation effect. However the number of pulses of rTMS is also important factor. In this study, we focused on the number of pulses. We used the cognitive task of perceptual reversal and compared the rTMS effects of different condition under 1Hz which is the inhibition condition. It has been known that the right superior parietal lobule (SPL) has a role in perceptual reversal. We applied rTMS over the SPL and measured the inter-reversal time (IRT) of perceptual reversal. The results showed that when 0.25Hz 60pulses, 0.5Hz 60pulses and 1Hz 60pulses of rTMS was applied over the right SPL, the IRT was significantly smaller. On the other hand, when 1Hz 240pulses of rTMS was applied over the right SPL, the IRT was significantly longer. When 0.25Hz 120pulses, 0.5Hz 120pulses and 1Hz 120pulses of rTMS was applied over the right SPL, there were no significant differences. Furthermore, to investigate the rTMS effects, when rTMS are applied over the motor area, we measured the motor evoked potential (MEP). The more pulses of rTMS was applied, the smaller the amplitude of MEP became. From these results, it was found that the IRT of perceptual reversal and the amplitude of MEP primarily affected by the number of pulses of rTMS. .
110. Keiji Iramina, Yoshinori Katayama, Yuichiro Kamei, Evaluation system for minor nervous dysfunction by pronation and supination of forearm using wireless acceleration and angular velocity sensors, 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 10.1109/IEMBS.2011.6091841 , 7364 - 7367 , 2011.08, We developed a simple, portable and easy system to the motion of pronation and supination of the forearm. This motion was measured by wireless acceleration and angular velocity sensor. The aim of this system is evaluation of minor nervous dysfunction. It is for the screening of the developmental disorder child. In this study, in order to confirm the effectiveness of this system, the reference curve of the neuromotor development was experimentally obtained. We studied 212 participants (108 males, 104 females) aged 7 to 12 years attending the kindergarten school. We could obtain the reference curve of the neuromotor development using this system. We also investigated the difference of neuromotor function between normally developed children and a ADHD child. There is a possibility that abnormality of the minor nervous dysfunction can be detected by using this system. .
111. Mingdi Xu, Keiji Iramina, The influence of stimulus onset asynchrony on neuronal suppressive phenomenon in face processing: An event-related potential study, 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 10.1109/IEMBS.2011.6090956 , 3849 - 3852 , 2011.08, It has been reported that if two sensory stimuli are presented consecutively with stimulus onset asynchrony (SOA) of as short as several hundreds of milliseconds, the neural activity, elicited by the second stimulus, in the stimulus-sensitive area will be inhibited, say, suppressive phenomenon. Using a paired-stimulus paradigm, in which two visual stimuli were successively presented, we investigated the influence of SOA (200ms, 400ms & 600ms) on suppressive phenomenon in face processing. Twelve subjects were asked to passively view randomly ordered paired stimuli and single stimuli, while their event-related potentials (ERPs) were recorded simultaneously. To evaluate the suppression, we compared the ERPs elicited by the second face stimulus of the paired stimuli with that elicited by the single face stimulus. It was found that, comparing with the ERPs elicited by single faces, in all three SOA conditions, the ERPs elicited by the second face stimulus of the intra-category trials (face_face trials) were more suppressed than those of the inter-category trials (blank_face and building_face trials) in both occipitotemporal and frontal regions. We surmised that these results might support a “domain specific” theory, which suggested that visual processing of faces and non-face objects involve separate and specialized networks in the ventro-lateral temporal cortex. Interestingly, for the face_face trials, as the SOA increased, the ERP suppression in the frontal region diminished gradually. Such phenomenon might be due to the lasting effect of semantic processing for the first face stimulus..
112. Yoshinori Katayama, Keiji Iramina, Fitting and Eliminating to the TMS Induced Artifact on the Measured EEG by the Equivalent Circuit Simulation Improved Performance, IFMBE proceedings 5th Kuala Lumpur International Conference on Biomedical Engineering 2011 , 35, 519-522, 2011.06.
113. Kazuhisa Nojima, Yoshinori katayama, Keiji Iramina, Number of pulses of rTMS affects the inter-reversal time of perceptual reversal, IFMBE proceedings 5th Kuala Lumpur International Conference on Biomedical Engineering 2011 , 35, 336-339, 2011.06.
114. Tetsuya Torii, Kazuhisa Nojima, Atsushi Matsunaga, Masakuni Iwahashi, Keiji Iramina, Comparison of Influences on P300 Latency in the Case of Stimulating Supramarginal Gyrus and Dorsolateral Prefrontal Cortex by rTMS, IFMBE proceedings 5th Kuala Lumpur International Conference on Biomedical Engineering 2011 , 35, 492-495, 336-339, 2011.06.
115. Keiji Iramina, Kana Matsuda, Junko Ide, Yukio Noguchi, Monitoring system of neuronal activity and moving activity without restraint using wireless EEG, NIRS and accelerometer
, 2010 IEEE EMBS Conference on Biomedical Engineering and Sciences (IECBES), , 10.1109/IECBES.2010.5742285 , 481 - 484, 2010.12.
116. Atsushi Matsunaga, Kazuhisa Nojima, Masakuni Iwahashi, Yoshinori Katayama, Keiji Iramina, The effect of TMS to supramarginal gyrus on event-related potential P300, 2010 IEEE Region 10 Conference, 10.1109/TENCON.2010.5686122, 1757-1760, 2010.11.
117. Kazuhisa Nojima, Yoshinori Katayama. Keiji Iramina, Change of EEG activity by repetitive Transcranial Magnetic Stimulation, 2010 IEEE Region 10 Conference, 10.1109/TENCON.2010.5686653 , 355-358, 2010.11.
118. Daisuke Nomura, Yoshinori Katayama, Keiji Iramina, The long-lasting effect caused by direct current for somatosensory evoked potentials and high frequency oscillations, 2010 IEEE Region 10 Conference, 10.1109/TENCON.2010.5686656 , 369-372, 2010.11.
119. Kazuhisa Nojima, Ge Sheng, Yoshinori Katayama, Keiji Iramina, Time change of perceptual reversal of ambiguous figures by rTMS
, 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) , 10.1109/IEMBS.2010.5627115 , 6759-6582, 2010.09.
120. Kana Matsuda, Saki Fujiyama, Keiji Iramina, NON-RESTRAINT MEASUREMENT OF BRAIN ACTIVITY OF THE CHILD WITH MENTAL RETARDATION USING WIRERESS EEG AND WIRELESS NIRS, The 3rd Biomedical Engineering International Conference 2010, 222-224, 2010.08.
121. Daisuke Nomura, Yoshinori Katayama, Keiji Iramina, LONG – TERM CHANGES OF HIGH FREQUENCY COMPONENTS CAUSED BY DIRECT CURRENT STIMULATIONS OVER SOMATOSENSOERY CORTEX, The 3rd Biomedical Engineering International Conference 2010, 193-195, 2010.08.
122. Keiichiro Koga, Keiji Iramina, MEASUREMENT OF EEG DURING WALKING USING WIRELESS TRANSMITTING EEG, The 3rd Biomedical Engineering International Conference 2010, 151-153, 2010.08.
123. Kazuhisa Nojima, Ge Sheng, Yoshinori Katayama, Shoogo Ueno, Keiji Iramina, Effect of the stimulus frequency and pulse number of rTMS on the inter-reversal time of perceptual reversal on the right SPL, Journal of Applied Physics, 10.1063/1.3357987 , 107, 09B320 1-3, 2010.05.
124. Nicolas A Zilber, Yoshinori Katayama, Keiji Iramina, Wintermantel Erich, Efficiency test of filtering methods for the removal of transcranial magnetic stimulation artifacts on human electroencephalography with artificially transcranial magnetic stimulation-corrupted signals
, Journal of Applied Physics, 10.1063/1.3357345 , 107, 9, 09B305 - 09B305-3 , 2010.05.
125. Seichi Tsuyama, Yoshinori Katayama, Akira Hyodo, Shoogo Ueno, Keiji Iramina, Effects of Coil Parameters on the Stimulated Area by Transcranial Magnetic Stimulation, IEEE Transactions on Magnetics, Vol. 45, 4845-4848, 2009.10.
126. Yoshinori Katayama, Keiji Iramina, Equivalent Circuit Simulation of the Induced Artifacts Resulted From Transcranial Magnetic Stimulation on Human Electroencephalography, IEEE Transactions on Magnetics, Vol. 45 4833-4836, 2009.10.
127. Akira Hyodo, Shoogo ueno, Keiji Iramina, Influence of Coil Current Configuration in Magnetic Stimulation of a Nerve Fiber in Inhomogeneous and Anisotropic Conducting Media, Proceedings of 31th Annual International IEEE EMBS Conference, MInneapolis, Minnesota,USA, September 2-6, 2009, 6501-6503, 2009.09.
128. Masakuni Iwahashi, Yoshinori Katayama, Shoogo ueno, Keiji Iramina, Effect of Transcranial Magnetic Stimulation on P300 of Event-Related Potential, Proceedings of 31th Annual International IEEE EMBS Conference, MInneapolis, Minnesota,USA, September 2-6, 2009, 1359-1362, 2009.09.
129. Mingdi XU, Saki Fujiyama, Keiji Iramina, Suppressive phenomenon in the higher-order functional regions: An EEG study with paired stimulus paradigm, Brain Topography and Multimodal Imaging, Proceedings of the 18th International Congress on Brain Electromagnetic Topography, 31-34, 2009.09.
130. Takahiro Matsunaga, Tetsuya Fukuta, Yoshinori Katayama, Keiji Iramina, Analysis of evoked response and induced response in alpha wave and gamma wave during visual attention, Brain Topography and Multimodal Imaging, Proceedings of the 18th International Congress on Brain Electromagnetic Topography, 23-26, 2009.09.
131. Saki Fujiyama, Keiji Iramina, Measurement of brain activity in children without restraint using wireless EEG, Brain Topography and Multimodal Imaging, Proceedings of the 18th International Congress on Brain Electromagnetic Topography, 195-198, 2009.09.
132. Akira Hyodo, Takehito Hayami, Seichi Tsuyama, Keiji Iramina, and Shoogo Ueno, Effects of stimulus parameters and tissue inhomogeneity on nerve excitation processes in magnetic stimulation of the brain, J. Appl. Phys., Vol. 105, 07B304, 2009.04.
133. Masakuni Iwahashi, Yohei Koyama, Akira Hyodo, Takehito Hayami, Shoogo Ueno, and Keiji Iramina, Measurements of evoked electroencephalograph by transcranial magnetic stimulation applied to motor cortex and posterior parietal cortex
, J. Appl. Phys., Vol. 105, 07B321, 2009.04.
134. Keiji Iramina, Sheng Ge, Akira Hyodo, Takehito Hayami, and Shoogo Ueno, Disturbance of visual search by stimulating to posterior parietal cortex in the brain using transcranial magnetic stimulation, J. Appl. Phys., Vol. 105, 07B302, 2009.04.
135. Takehito Hayami, Keiji Iramina, Akira Hyodo, Xian Chen, and Kenji Sunagawa, Detection of a diabetic sural nerve from the magnetic field after electric stimulation, J. Appl. Phys., Vol. 105, 07B315, 2009.04.
136. Seichi Tsuyama, Akira Hyodo, Masaki Sekino, Takehito Hayami, Shoogo Ueno and Keiji Iramina, The numeric calculation of eddy current distributions in transcranial magnetic stimulation, Proceedings of 30th Annual International IEEE EMBS Conference, Vancouver, British Columbia, Canada, August 20-24, 2008, 4286-4289, 2008.08.
137. Takahiro Matsunaga, Yoshinori Katayama, Takehito Hayami, Keiji Iramina, Measurements of the mu/beta ERD and gamma ERS during the imagination of body parts movement, Proceedings of 30th Annual International IEEE EMBS Conference Vancouver, British Columbia, Canada, August 20-24, 2008, 4130-4133, 2008.08.
138. Saki Fujiyama Yul-Wan SUNG Seiji Ogawa Takehito Hayami Keiji Iramina, Measurement of Evoked Potential in Recognition of Faces and Buildings, Proceedings of 30th Annual International IEEE EMBS Conference Vancouver, British Columbia, Canada, August 20-24, 2008, 4126-4129, 2008.08.
139. M. Iwahashi, T. Arimatsu, S. Ueno, and K. Iramina, Differences in Evoked EEG by Transcranial Magnetic Stimulation at Various Stimulus Points on the Head, Proceedings of 30th Annual International IEEE EMBS Conference Vancouver, British Columbia, Canada, August 20-24, 2008, 2570-2573, 2008.08.
140. Sheng Ge, Shoogo Ueno, Keij Iramina, Effects of Repetitive Transcranial magnetic Stimulation on Perceptual Reversal, Journal of the Magnetics Society of Japan, Vol.32 No.4, 458-461, 2008.07.
141. Differences in evoked EEG by Transcranial Magnetic Stimulation applied to motor Cortex and Posterior Parietal Coetex.
142. Sheng Ge, Makoto Ichikawa, Atsushi Osa, Keiji Iramina, Hidetoshi Miike, Spatial and Temporal Frequency Tuning of Motion-in-Depth Aftereffect, IEEJ Transactions on Electronics, Information and Systems, Vol. 128, No.7, 1015-1022, 2008.07.
143. Mingdi Xu, Takehito Hayami, Keiji Iramina, Discrimination of Finger Area of Somatosensory Cortex by NIRS, IEEJ Transactions on Electronics, Information and Systems, Vol. 128, No.7, 1183-1184, 2008.07.
144. K. Iramina, T. Hyami, G. Sheng, Effect of Transcranial Magnetic Stimulation on Visual Perception, Proceedings of the International Symposium on Biological and Physiological Engineering, 50-53, 2008.01.
145. Sheng Ge, Makoto Ichikawa, Atsushi Osa, Keiji Iramina, Hidetoshi Miike, The Proposal of a Neuron Model in Consideration of Facilitation and Fatigue, 電気学会論文誌 電子・情報・システム, Volume 127-C Number 10, 1673-1679, 2007.10.
146. Sheng Ge, Akira Matsuoka, Shoogo Ueno, Keiji Iramina , A Study of Temporal Aspect of Posterior Parietal Cortex in Visual Search Using Transcranial Magnetic Stimulation , 電気学会論文誌 電子・情報・システム, Volume 127-C Number 10, 1651-1657, 2007.10.
147. Hirotsugu Takata, Mingdi Xu, Takehito Hayami and Keiji Iramina, Effect of Electrical Stimulus Intensity to Hemodynamic Responses of Somatosensory cortex, Proc. of the Noninvasive Functional Source Imaging of the Brain and Heart and the International Conference on Functional Biomedical Imaging, 280-282, 2007.10.
148. Takeshi Arimatsu, Hideyuki Sato, Sheng Ge, Shoogo Ueno, Keiji Iramina, Measurements of EEG Evoked by Transcranial Magnetic Stimulation at Various Stimulus Points on the Head, Proc. of the Noninvasive Functional Source Imaging of the Brain and Heart and the International Conference on Functional Biomedical Imaging, 334-337, 2007.10.
149. Mingdi XU, Hirotsugu Takata, Sheng Ge, Takehito Hayami, Takao Yamasaki, Shozo Tobimatsu, Keiji Iramina, NIRS Measurement of Hemodynamic Evoked Responses in the Primary Sensorimotor Cortex, Proceedings of the 29th IEEE EMBS Annual International Conference, pp.2492-2495, 2007.08.
150. Akira Matsuoka, Yuuji Kawamura, Sheng Ge, Shoogo Ueno, Keiji Iramina, Temporal aspect of three visual search tasks by using TMS, Proceedings of the 29th IEEE EMBS Annual International Conference, pp.4751-4754, 2007.08.
151. Sheng Ge, Shoogo Ueno and Keiji Iramina, The rTMS Effect on Perceptual Reversal of Ambiguous Figures, Proceedings of the 29th IEEE EMBS Annual International Conference, pp.4743-4746, 2007.08.
152. Takehito Hayami, Keiji Iramina, Xian Chen and Kenji Sunagawa, Simulation Study on the Effect of Fiber Loss to the Compound Action Potential of a Sural Nerve, Proceedings of the 29th IEEE EMBS Annual International Conference, pp.2396-2399, 2007.08.
153. Keiji Iramina, Shoogo Ueno, High Spatial Resolutional Measurementof Biomagnetic Field, IEEE Transactions on Magnetics, Volume 43, Issue 6, 2477 - 2479, 2007.06.
154. Takehito Hayami, Keiji Iramina, Xian Chen, Modeling Complex Current Waves of a Sural Nerve after Electric Stimulation in case of A Thin Myelin Sheath, Proceedings of 2007 IEEE/ICME International Conference on Complex Medical Engineering, 1882-1886, 2007.05.
155. Mingdi XU, Hirotsugu TAKATA, Sheng GE, Takehito HAYAMI, Takao YAMASAKI, Shoozo TOBIMATSU, Keiji IRAMINA , Responses in the Primary Somatosensory Cortex by Finger Stimulation, Proceedings of 2007 IEEE/ICME International Conference on Complex Medical Engineering, 1450-1454, 2007.05.
156. Sheng GE, Shoogo UENO, Keiji IRAMINA, Repetitive Transcranial Magnetic Stimulation Effect on Perceptual Reversals of Ambiguous Figures , Proceedings of 2007 IEEE/ICME International Coferece on Complex Medical Engineering, 1425-1428, 2007.05.
157. Sheng Ge, Shoogo Ueno, and Keiji Iramina, Temporal Analysis of Visual Search Task by Transcranial Magnetic Stimulation, Proceedings of PIERS 2007, 241‐243, 2007.03.
158. Takehito Hayami and Keiji Iramina, Magnetic Field Produced by Compound Action Potential of Degenerated Human Nerve, Proceedings of PIERS 2007, 1929-1931, 2007.03.
159. Sheng Ge, Takashi Saito, Jing-long Wu, Jun-ichi Ogasawara, Shuichi Yamauchi, Naofumi Matsunaga, Keiji Iramina, The Neural Substrates for Letter String Readings in The Normal and Reverse Directions: An fMRI Study, IEEJ Transactions on Electronics, Information and Systems, Vol.127, No.3, 353-358, 2007.03.
160. Klevest Gjini, Takashi Maeno, Keiji Iramina, Joji Ando, Shoogo Ueno, Working memory processing of natural environmental scenes in the human brain revealed by MEG, International Congress Series, 1300, 409-412, 2007.01.
161. Sheng Ge, Akira Matsuoka, Shoogo Ueno, keiji Iramina, Transcranial magnetic stimulation study of temporal aspect of posterior parietal cortex in visual search, International Congress Series, 1300, 287-290, 2007.01.
162. Sheng Ge, Akira Matsuoka, Shoogo Ueno, Keiji Iramina, TMS effect on visual search task, Proceedings of the 28th IEEE EMBS Annual International Conference, pp.1118-1120, 2006.09.
163. Sheng Ge, Takashi Saito, Jing-Long Wu, Keiji Iramina, A study on some optical illusions based upon the theory of inducing field, Proceedings of the 28th IEEE EMBS Annual International Conference, 4205-4208, 2006.09.
164. Akira Matsuoka, Sheng Ge, Shoogo Ueno, Keiji Iramina, A TMS study of temporal aspect of the posterior parietal cortex involved in visual search, Proceedings of World Congress on Medical Physics and Biomedical Engineering 2006, 2656-2658, 2006.08.
165. Yuji Matsumoto, Sheng Ge, Keiji Iramina, Measurement of visual evoked potential by facial perception, Proceedings of World Congress on Medical Physics and Biomedical Engineering 2006, 2659-2661, 2006.08.
166. Hideyuki Sato, Sheng Ge, Keiji Iramina, Shoogo Ueno , Evoked EEG mapping during transcranial magnetic stimulation, Proceedings of World Congress on Medical Physics and Biomedical Engineering 2006, 2669-2671, 2006.08.
167. Sheng Ge, Makoto Ichikawa, Atsushi Osa, Hidetoshi Miike, Keiji Iramina , The proposal of a neuron model in consideration of facilitation and fatigue , Proceedings of World Congress on Medical Physics and Biomedical Engineering 2006, 2659-2661, 2006.08.
168. K.IRAMINA, T.MAENO, S.UENO, Topography of EEG Responses Evoked by transcranial magnetic stimulation to the cerebellum, IEEE Transactions on Magnetics, 40(4), pp.2982-2984, 2004.04.