Browsing by Author "Lo, Pei-Chen"

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Brain-controlled robot agent: an EEG-based e Robot agent
(2008)
Wu, Li-Wei
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Liao, Hsien-Cheng
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Hu, Jwu-Sheng
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Lo, Pei-Chen
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電控工程研究所
Purpose - This paper aims to present a novel embedded-internet robot system based on an internet robot agent and the brain-computer interface (BCI) scheme. Design/methodology/approach - A highly flexible and well-integrated embedded ethernet robot (e Robot) was designed with enhanced mobility. In the e Robot, a circuit core module called a tiny network bridge (TNB) is designed to reduce robotic system cost and increase its mobility and developmental flexibility. The TNB enables users to control e Robot motion via embedded ethernet technology. Through electroencephalogram (EEG) feedback training, the command translation unit (CTU) and alertness level detection unit (ADU) allow the e Robot to perform specific motions (for example, lying down or standing up) to reflect alertness levels of the user, and move forward, turn left or right following the user's command. Findings - After a short training period, subjects could achieve at least 70 percent accuracy in the CTU game testing. And the error rate of ADU, estimated from the results of classifying 496 labeled EEG epochs, was approximately 10.7 percent. Combining an encoding procedure, the commands issued from the CTU could prevent the robot from performing undesired actions. Originality/value - The e Robot could reflect some physiological human states and be controlled by users with our economical design and only two bipolar EEG channels adopted. Thus, users could make the EEG-based e Robot agent his or her representative. Based on the proposed EEG-based e Robot system, a robot with increased sophistication will be developed in the future for use by disabled patients.
Cardiorespiratory phase synchronization during normal rest and inward-attention meditation
(2010-06-11)
Wu, Shr-Da
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Lo, Pei-Chen
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電控工程研究所
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Institute of Electrical and Control Engineering
EFFECT OF ZEN MEDITATION PRACTICE ON PERCEIVED STRESS IN COLLEGE STUDENTS: A SURVEY STUDY
(2007-12-01)
Lo, Pei-Chen
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Wu, Shr-Da
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電控工程研究所
;
Institute of Electrical and Control Engineering
Most physical and psychological problems in modern people have been proven to be caused by stress. This finding stimulated the demand for techniques that can effectively manipulate the stress perception. The influence of stress on college students lasts longer at the age when there is a fast development of personality and life viewpoint. This survey study thus mainly examines the effect of Zen-meditation practice on stress manipulation in college students. 541 college students were divided into two groups, with Zen-meditation practice in their daily lives and those who do not meditate. To evaluate the perceived stress of participants, DASS questionnaire was used to measure their negative emotional states (depression, anxiety and stress/tension). The results showed that (1) considerably high percentage of college students who did not practice Zen meditation exhibited negative emotional problem (depression: 45%; anxiety: 48%; stress/tension: 50%); (2) a much lower percentage of students with meditation practice encountered the negative emotional problem (depression: 8%; anxiety: 30%; stress/tension: 12%). This study reflects the benefits of meditation on stress manipulation. It may also imply that having more meditation, having longer meditation time, and doing meditation more frequently could further improve the states of negative emotion. It also implies that meditation experience played a considerable role in effectively manipulating some stress symptoms like depression and anxiety. This is demonstrated by the significantly lower scores (p < 0.001) in the group of experienced (> 0.5 year) meditators as compared with the control group.
Effects of Long-Term Dharma-Chan Meditation on Cardiorespiratory Synchronization and Heart Rate Variability Behavior
(2013-04-01)
Chang, Chih-Hao
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Lo, Pei-Chen
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電機工程學系
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Department of Electrical and Computer Engineering
Remarkable changes in cardiorespiratory interactions are frequently experienced by Chan meditation practitioners following years of practice. This study compares the results of our study on cardiorespiratory interactions for novice (control group) and experienced (experimental group) Chan meditation practitioners. The effectual coaction between the cardiac and respiratory systems was evaluated by the degree of cardiorespiratory phase synchronization (CRPS). In addition, an adaptive-frequency-range (AFR) scheme to reliably quantify heart rate variability (HRV) was developed for assessing the regulation of sympathetic-parasympathetic activity and the efficiency of pulmonary gas exchange. The enhanced HRV method, named HRVAFR, can resolve the issue of overestimating HRV under the condition of slow respiration rates, which is frequently encountered in studies on Chan meditation practitioners. In the comparison of the three data sets collected from the two groups, our findings resulted in innovative hypotheses to interpret the extraordinary process of the rejuvenation of cardiorespiratory functions through long-term Dharma-Chan meditation practice. Particularly, advanced practitioners exhibit a continuously high degree of cardiorespiratory phase synchronization, even during rapid breathing. Based on our post-experimental interview with advanced practitioners, the activation of inner Chakra energy, during the course of Chan-detachment practice, frequently induces perceptible physiological-mental reformation, including an efficient mechanism for regulating cardiorespiratory interactions.
F-VEP AND ALPHA-SUPPRESSED EEG-PHYSIOLOGICAL EVIDENCE OF INNER-LIGHT PERCEPTION DURING ZEN MEDITATION
(2006-02-25)
Chang, Kang-Ming
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Lo, Pei-Chen
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper firstly reports the visual response to the inner light (a form of qi) and the outside stimulus during Zen meditation. It has been reported literally that inner light perception is the common experience for prayers or Zen-meditation practitioners. In this paper, we propose a method to quantify the EEG (electroencephalograph) and F-VEP (flash visual evoked potential) that characterize this experience. Based on wavelet analysis, we derived a set of parameters that effectively signify the alpha-suppressed EEG pattern. Furthermore, this paper presents our new results of analyzing the F-VEP data, mainly the peak amplitude. The observation of little variation in amplitude during Zen meditation reflects a more stable visual perceptive system during Zen meditation that is contrary to the visual response of the control subjects under eye-closed relaxation.
F-VEPs in Zen meditation
(2008-04-01)
Liu, Chuan-Yi
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Lo, Pei-Chen
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電控工程研究所
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Institute of Electrical and Control Engineering
The observation of the inner-light perception in deep Zen meditation(14) has aroused our attention. Based on the recording of F-VEPs (. ash visual evoked potentials), this study was thus designed to investigate the characteristics of visual nervous pathway for the Zen-meditation practitioners ( experimental group), in comparison with that for the normal, healthy subjects ( control group). Flash stimuli were applied before, during and after meditation/ relaxation in experimental/ control subjects. We focused on the F-VEPs at the occipital site Oz, central site Cz and frontal site Fz. Our results show that amplitudes of late latency components N3-P3 and P3-N4 at Oz decrease for the experimental subjects during meditation, whereas they increase in the control group. Both Cz and Fz amplitudes increase during meditation, yet decrease during relaxation for the control group. The latencies of some components were increased under relaxation in control group, yet little variation ( except P2) is observed in the meditators. We also applied discrete wavelet transform to F-VEPs to analyze the frequency components. Our results showed that delta, theta and alpha components increased during meditation at some specific time periods. According to our findings, Zen meditation induces particular effects on the visual nervous system and cortex that are distinct from the normal relaxation.
Investigation of meditation scenario by quantifying the complexity index of EEG
(2007-05-01)
Lo, Pei-Chen
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Huang, Hsuan-Yung
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電控工程研究所
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Institute of Electrical and Control Engineering
A practitioner in true meditation should already transcend the physiological, mental, subconscious, and Alaya state, and eventually attain the spiritual realm. The scientific approach to the scope of Zen meditation provides insight into the mechanism in addition to the vague sketch of meditation sensation and its multiform benefits to human beings. In meditation research, it is difficult to access changes of the consciousness state during meditation. Meditators once transcending the physiological and mental state cannot convey information outside. As a consequence, quantitative results together with post-experimental, subjective narration may provide us with a glimpse of the meditation scenario. This paper mainly reports our preliminary results of quantifying the long-term brain waves, recorded by the electroencephalogram (EEG), for both experimental (meditators) and control groups. Based on the nonlinear dynamic analysis of multi-channel EEG signals, we found that brain dynamics exhibited high delta (Phi/beta EEG) in deep meditation. Three different meditation scenarios have been identified from the running 37 (averaged complexity index) chart. Spatial characteristics also deviate from that of the control group. This observation was summarized from the results of analyzing the meditation EEG's collected from 17 Zen-Buddhist practitioners and 16 control Subjects.
Inward-attention meditation increases parasympathetic activity: a study based on heart rate variability
(2008-10-01)
Wu, Shr-Da
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Lo, Pei-Chen
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電控工程研究所
;
Institute of Electrical and Control Engineering
Phenomenon of the heart rate variability (HRV) during various meditation techniques has been reported. However, most of these techniques emphasized the skill of slow breathing (< 0.15 Hz). This paper reports our study on HRV during meditation which emphasizes inward attention. Inward attention has been an important approach for the Zen-meditation practitioners to enter into transcendental consciousness. Two groups of subjects were investigated, 10 experimental Subjects with Zen-meditation experience and 10 control subjects without any meditation experience. We analyzed HRV both in time and frequency domains. The results revealed both common and different effects on HRV between inward-attention meditation and normal rest. The major difference of effects between two groups were the decrease of LF/HF ratio and LF norm as well as the increase of HF norm, which suggested the benefit of a sympathovagal balance toward parasympathetic activity. Moreover, we observed regular oscillating rhythms of the heart rate when the LF/HF ratio was small under meditation. According to previous studies, regular oscillations of heart rate signal usually appeared in the low-frequency band of HRV under slow breathing. Our findings showed that such regular oscillations could also appear in the high-frequency band of HRV but with smaller amplitude.
MEDITATION EEG INTERPRETATION BASED ON NOVEL FUZZY-MERGING STRATEGIES AND WAVELET FEATURES
(2005-08-25)
Chang, Kang-Ming
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Lo, Pei-Chen
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電控工程研究所
;
Institute of Electrical and Control Engineering
As the advantages of meditation have been outlined literally, scientific exploration of the meditation phenomena becomes significant. Meditation EEG may provide an access to the mental states beyond normal consciousness. It is the first attempt to score the meditation course by EEG. Wavelet analysis and fuzzy c-means (FCM) are applied in the automatic interpretation algorithm. However, FCM applied straightforward to quantitative feature vectors often results in an over-trifling interpretation. As a consequence, this paper presents novel cluster-managing strategies for achieving an interpretation closer to the result of naked-eye examination. The running gray-scale chart, derived by extracting, clustering, and coding the EEG features, reveals five different meditation scenarios differing from those of the controlled subjects.
MICROSTATE ANALYSIS OF ALPHA-EVENT BRAIN TOPOGRAPHY DURING CHAN MEDITATION
(2009)
Lo, Pei-Chen
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Zhu, Qiang
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper reports our preliminary result of microstate analysis for the spatiotemporal characteristics of Chan-meditation brain wave (electroencephalograph, EEG) based on time-varying dipolar-vector model of the alpha-map. Microstate behavior reveals subtle transience of focalized event. Multi-channel alpha-event epochs were identified by Wavelet decomposition and feature extraction. Global field power was adopted as the criterion to choose alpha-map candidates (normalized alpha-power vectors), that were further classified by Mahalanobis Fuzzy C-means into different region-focalization states. Transition between various alpha-event focalization states was ready to be explored via microstate analysis. Our findings reveal that Chan-meditation practitioners exhibit longer duration of frontal alpha-event microstate, reflecting sustained stability of the brain generators.
Spatially Nonlinear Interdependence of Alpha-Oscillatory Neural Networks under Chan Meditation
(2013)
Lo, Pei-Chen
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Chang, Chih-Hao
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper reports the results of our investigation of the effects of Chan meditation on brain electrophysiological behaviors from the viewpoint of spatially nonlinear interdependence among regional neural networks. Particular emphasis is laid on the alpha-dominated EEG (electroencephalograph). Continuous-time wavelet transform was adopted to detect the epochs containing substantial alpha activities. Nonlinear interdependence quantified by similarity index S(X vertical bar Y), the influence of source signal Y on sink signal X, was applied to the nonlinear dynamical model in phase space reconstructed from multichannel EEG. Experimental group involved ten experienced Chan-Meditation practitioners, while control group included ten healthy subjects within the same age range, yet, without any meditation experience. Nonlinear interdependence among various cortical regions was explored for five local neural-network regions, frontal, posterior, right-temporal, left-temporal, and central regions. In the experimental group, the inter-regional interaction was evaluated for the brain dynamics under three different stages, at rest (stage R, pre-meditation background recording), in Chan meditation (stage M), and the unique Chakra-focusing practice (stage C). Experimental group exhibits stronger interactions among various local neural networks at stages M and C compared with those at stage R. The intergroup comparison demonstrates that Chan-meditation brain possesses better cortical inter-regional interactions than the resting brain of control group.
Variation Analysis of Sphygmogram to Assess Cardiovascular System under Meditation
(2009-03-01)
Liu, Chuan-Yi
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Wei, Ching-Chuan
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Lo, Pei-Chen
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電控工程研究所
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電信工程研究所
In this article, we studied how meditation affects the characteristics of the cardiovascular system, mainly based on blood pressure waveforms (BPW). Four parameters derived from BPW include the rising slope (h(1)/t(1)), normalized height of T wave (h(3)/h(1)), normalized height of V(3) valley (h(4)/h(1)) and normalized height of D wave (h(5)/h(1)), where t(1) and h(i), i 1, ,5 are quantitative features of the BPW waveform pattern. A larger value of h(1)/t(1) reflects better heart ejection ability and aorta compliance. A larger value of h(3)/h(1) may infer an arterial system with good elasticity. The decrease (increase) of h(4)/h(1) parameter indicates the decrease (increase) of peripheral resistance of vessels. A larger value of h(5)/h(1) indicates better artery elasticity and aortic valve function. In comparison with the control group, Zen-meditation practitioners have more after-meditation h(1)/t(1), h(3)/h(1) and h(5)/h(1) increase, with more h(4)/h(1) decrease, with statistical significance (P 0.05). The observation allows us to infer that Zen meditation may effectively improve relevant characteristics of the cardiovascular system.