Berg, Sebastian

[["dc.bibliographiccitation.journal","Frontiers in Physiology"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Kottlarz, Inga"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Toscano-Tejeida, Diana"],["dc.contributor.author","Steinmann, Iris"],["dc.contributor.author","Bähr, Mathias"],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Wilke, Melanie"],["dc.contributor.author","Parlitz, Ulrich"],["dc.contributor.author","Schlemmer, Alexander"],["dc.date.accessioned","2021-04-14T08:29:50Z"],["dc.date.available","2021-04-14T08:29:50Z"],["dc.date.issued","2021"],["dc.description.abstract","In this study, ordinal pattern analysis and classical frequency-based EEG analysis methods are used to differentiate between EEGs of different age groups as well as individuals. As characteristic features, functional connectivity as well as single-channel measures in both the time and frequency domain are considered. We compare the separation power of each feature set after nonlinear dimensionality reduction using t-distributed stochastic neighbor embedding and demonstrate that ordinal pattern-based measures yield results comparable to frequency-based measures applied to preprocessed data, and outperform them if applied to raw data. Our analysis yields no significant differences in performance between single-channel features and functional connectivity features regarding the question of age group separation."],["dc.identifier.doi","10.3389/fphys.2020.614565"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82999"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.publisher","Frontiers Media S.A."],["dc.relation.eissn","1664-042X"],["dc.rights","http://creativecommons.org/licenses/by/4.0/"],["dc.title","Extracting Robust Biomarkers From Multichannel EEG Time Series Using Nonlinear Dimensionality Reduction Applied to Ordinal Pattern Statistics and Spectral Quantities"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","265"],["dc.bibliographiccitation.journal","Communications in Nonlinear Science and Numerical Simulation"],["dc.bibliographiccitation.lastpage","281"],["dc.bibliographiccitation.volume","37"],["dc.contributor.author","Otte, Stefan"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Parlitz, Ulrich"],["dc.date.accessioned","2018-11-07T10:11:26Z"],["dc.date.available","2018-11-07T10:11:26Z"],["dc.date.issued","2016"],["dc.description.abstract","The dynamics of a detailed ionic cardiac cell model proposed by Sato et al. (2009) is investigated in terms of periodic and chaotic action potentials, bifurcation scenarios, and coexistence of attractors. Starting from the model's standard parameter values bifurcation diagrams are computed to evaluate the model's robustness with respect to (small) parameter changes. While for some parameters the dynamics turns out to be practically independent from their values, even minor changes of other parameters have a very strong impact and cause qualitative changes due to bifurcations or transitions to coexisting attractors. Implications of this lack of robustness are discussed. (C) 2016 The Authors. Published by Elsevier B.V."],["dc.identifier.doi","10.1016/j.cnsns.2016.01.014"],["dc.identifier.isi","000371316800019"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14151"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40042"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/134"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C03: Erholung nach Herzinsuffizienz: Analyse der transmuralen mechano-elektrischen Funktionsstörung"],["dc.relation.issn","1878-7274"],["dc.relation.issn","1007-5704"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Luther (Biomedical Physics)"],["dc.rights","CC BY 4.0"],["dc.title","Bifurcations, chaos, and sensitivity to parameter variations in the Sato cardiac cell model"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","043012"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.lastpage","7"],["dc.bibliographiccitation.volume","18"],["dc.contributor.author","Shajahan, T. K."],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Krinski, Valentin"],["dc.contributor.author","Bittihn, Philip"],["dc.date.accessioned","2019-02-27T14:16:19Z"],["dc.date.available","2019-02-27T14:16:19Z"],["dc.date.issued","2016"],["dc.description.abstract","Spiral waves in cardiac tissue can pin to tissue heterogeneities and form stable pinned waves. These waves can be unpinned by electric stimuli applied close to the pinning center during the vulnerable window of the spiral. Using a phase transition curve (PTC), we quantify the response of a pinned wave in a cardiac monolayer to secondary excitations generated electric field pulses. The PTC can be used to construct a one-dimensional map that faithfully predicts the pinned wave’s response to periodic field stimuli. Based on this 1D map, we predict that pacing at a frequency greater than the spiral frequency, over drive pacing, leads to phase locking of the spiral to the stimulus, which hinders unpinning. In contrast, under drive pacing can lead to scanning of the phase window of the spiral, which facilitates unpinning. The predicted mechanisms of phase scanning and phase locking are experimentally tested and confirmed in the same monolayers that were used to obtain the PTC. Our results have the potential to help choose optimal parameters for low energy antifibrillation pacing schemes."],["dc.identifier.doi","10.1088/1367-2630/18/4/043012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/57648"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/168"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C03: Erholung nach Herzinsuffizienz: Analyse der transmuralen mechano-elektrischen Funktionsstörung"],["dc.relation.issn","1367-2630"],["dc.relation.workinggroup","RG Luther (Biomedical Physics)"],["dc.rights","CC BY 3.0"],["dc.title","Scanning and resetting the phase of a pinned spiral wave using periodic far field pulses"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","830"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","American Journal of Preventive Medicine"],["dc.bibliographiccitation.lastpage","838"],["dc.bibliographiccitation.volume","55"],["dc.contributor.author","Gupta, Soham"],["dc.contributor.author","Cole, Alexander P."],["dc.contributor.author","Marchese, Maya"],["dc.contributor.author","Wang, Ye"],["dc.contributor.author","Speed, Jacqueline M."],["dc.contributor.author","Fletcher, Sean A."],["dc.contributor.author","Nabi, Junaid"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Lipsitz, Stuart R."],["dc.contributor.author","Choueiri, Toni K."],["dc.contributor.author","Chang, Steven L."],["dc.contributor.author","Kibel, Adam S."],["dc.contributor.author","Uhlig, Annemarie"],["dc.contributor.author","Trinh, Quoc-Dien"],["dc.date.accessioned","2020-12-10T14:22:22Z"],["dc.date.available","2020-12-10T14:22:22Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1016/j.amepre.2018.07.021"],["dc.identifier.issn","0749-3797"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/71589"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Use of Preventive Health Services Among Cancer Survivors in the U.S."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4049"],["dc.bibliographiccitation.lastpage","4052"],["dc.contributor.author","Schlemmer, Alexander"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Shajahan, T. K."],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Parlitz, Ulrich"],["dc.date.accessioned","2019-02-27T15:58:02Z"],["dc.date.available","2019-02-27T15:58:02Z"],["dc.date.issued","2015"],["dc.description.abstract","Analyzing the dynamics of complex excitation wave patterns in cardiac tissue plays a key role for understanding the origin of life-threatening arrhythmias and for devising novel approaches to control them. The quantification of spatiotemporal complexity, however, remains a challenging task. This holds in particular for the analysis of data from fluorescence imaging (optical mapping), which allows for the measurement of membrane potential and intracellular calcium at high spatial and temporal resolution. Hitherto methods, like dominant frequency maps and the analysis of phase singularities, address important aspects of cardiac dynamics, but they consider very specific properties of excitable media, only. This article focuses on the benchmark of spatial complexity measures over time in the context of cardiac cell cultures. Standard Shannon Entropy and Spatial Permutation Entropy, an adaption of [1], have been implemented and applied to optical mapping data from embryonic chicken cell culture experiments. We introduce spatial separation of samples when generating ordinal patterns and show its importance for Spatial Permutation Entropy. Results suggest that Spatial Permutation Entropies provide a robust and interpretable measure for detecting qualitative changes in the dynamics of this excitable medium."],["dc.identifier.doi","10.1109/EMBC.2015.7319283"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/57653"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/145"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.publisher","IEEE"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C03: Erholung nach Herzinsuffizienz: Analyse der transmuralen mechano-elektrischen Funktionsstörung"],["dc.relation.conference","37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)"],["dc.relation.eventend","2015-08-29"],["dc.relation.eventlocation","Milan, Italy"],["dc.relation.eventstart","2015-08-25"],["dc.relation.isbn","978-1-4244-9270-1"],["dc.relation.ispartof","2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)"],["dc.relation.workinggroup","RG Luther (Biomedical Physics)"],["dc.title","Quantifying spatiotemporal complexity of cardiac dynamics using ordinal patterns"],["dc.type","conference_paper"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","093931"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Chaos: An Interdisciplinary Journal of Nonlinear Science"],["dc.bibliographiccitation.lastpage","14"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","Bittihn, Philip"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Parlitz, Ulrich"],["dc.contributor.author","Luther, Stefan"],["dc.date.accessioned","2019-02-26T16:35:12Z"],["dc.date.available","2019-02-26T16:35:12Z"],["dc.date.issued","2017"],["dc.description.abstract","Self-organized activation patterns in excitable media such as spiral waves and spatio-temporal chaos underlie dangerous cardiac arrhythmias. While the interaction of single spiral waves with different types of heterogeneity has been studied extensively, the effect of heterogeneity on fully developed spatio-temporal chaos remains poorly understood. We investigate how the complexity and stability properties of spatio-temporal chaos in the Bär–Eiswirth model of excitable media depend on the heterogeneity of the underlying medium. We employ different measures characterizing the chaoticity of the system and find that the spatial arrangement of multiple discrete lower excitability regions has a strong impact on the complexity of the dynamics. Varying the number, shape, and spatial arrangement of the heterogeneities, we observe strong emergent effects ranging from increases in chaoticity to the complete cessation of chaos, contrasting the expectation from the homogeneous behavior. The implications of our findings for the development and treatment of arrhythmias in the heterogeneous cardiac muscle are discussed. Understanding the mechanisms that govern the onset, development, and termination of cardiac arrhythmias is essential to develop and further refine novel strategies for controlling them. However, cardiac tissue is inherently heterogeneous, and heterogeneity might be exacerbated in diseased hearts. In a generic model of excitable media, we investigate how patches of lower excitability change the characteristics of spatio-temporal chaos, which is related to lethal cardiac fibrillation. Surprisingly, the presence of multiple discrete heterogeneities may lead to the complete cessation of chaos, even though lower excitability increases complexity in a homogeneous medium. In other cases, the complexity of spatio-temporal chaos increases beyond the values expected from homogeneous behavior. Our results show that spatial variations in local parameters may have truly emergent effects and information about the distribution of natural heterogeneity in the cardiac muscle as well as the spatial scale and strength of pathological heterogeneities is an indispensable prerequisite for understanding the stability properties of cardiac arrhythmias and developing control strategies tailored to specific types of dynamics."],["dc.identifier.doi","10.1063/1.4999604"],["dc.identifier.pmid","28964139"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/57628"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/184"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C03: Erholung nach Herzinsuffizienz: Analyse der transmuralen mechano-elektrischen Funktionsstörung"],["dc.relation.issn","1054-1500"],["dc.relation.workinggroup","RG Luther (Biomedical Physics)"],["dc.title","Emergent dynamics of spatio-temporal chaos in a heterogeneous excitable medium"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","20190420"],["dc.bibliographiccitation.issue","2230"],["dc.bibliographiccitation.journal","Proceedings of the Royal Society of London. Series A, Mathematical, Physical and Engineering Sciences"],["dc.bibliographiccitation.volume","475"],["dc.contributor.author","Punacha, Shreyas"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Sebastian, Anupama"],["dc.contributor.author","Krinski, Valentin I."],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Shajahan, T. K."],["dc.date.accessioned","2022-03-01T11:46:52Z"],["dc.date.available","2022-03-01T11:46:52Z"],["dc.date.issued","2019"],["dc.description.abstract","Rotating spiral waves of electrical activity in the heart can anchor to unexcitable tissue (an obstacle) and become stable pinned waves. A pinned rotating wave can be unpinned either by a local electrical stimulus applied close to the spiral core, or by an electric field pulse that excites the core of a pinned wave independently of its localization. The wave will be unpinned only when the pulse is delivered inside a narrow time interval called the unpinning window (UW) of the spiral. In experiments with cardiac monolayers, we found that other obstacles situated near the pinning centre of the spiral can facilitate unpinning. In numerical simulations, we found increasing or decreasing of the UW depending on the location, orientation and distance between the pinning centre and an obstacle. Our study indicates that multiple obstacles could contribute to unpinning in experiments with intact hearts."],["dc.description.abstract","Rotating spiral waves of electrical activity in the heart can anchor to unexcitable tissue (an obstacle) and become stable pinned waves. A pinned rotating wave can be unpinned either by a local electrical stimulus applied close to the spiral core, or by an electric field pulse that excites the core of a pinned wave independently of its localization. The wave will be unpinned only when the pulse is delivered inside a narrow time interval called the unpinning window (UW) of the spiral. In experiments with cardiac monolayers, we found that other obstacles situated near the pinning centre of the spiral can facilitate unpinning. In numerical simulations, we found increasing or decreasing of the UW depending on the location, orientation and distance between the pinning centre and an obstacle. Our study indicates that multiple obstacles could contribute to unpinning in experiments with intact hearts."],["dc.identifier.doi","10.1098/rspa.2019.0420"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/103830"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/314"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-531"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C03: Erholung nach Herzinsuffizienz: Analyse der transmuralen mechano-elektrischen Funktionsstörung"],["dc.relation.eissn","1471-2946"],["dc.relation.issn","1364-5021"],["dc.relation.workinggroup","RG Luther (Biomedical Physics)"],["dc.rights.uri","https://royalsociety.org/journals/ethics-policies/data-sharing-mining/"],["dc.title","Spiral wave unpinning facilitated by wave emitting sites in cardiac monolayers"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Frontiers in Physics"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Schlemmer, Alexander"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Lilienkamp, Thomas"],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Parlitz, Ulrich"],["dc.date.accessioned","2020-12-10T18:44:37Z"],["dc.date.available","2020-12-10T18:44:37Z"],["dc.date.issued","2018"],["dc.description.abstract","Permutation entropy (PE) is a robust quantity for measuring the complexity of time series. In the cardiac community it is predominantly used in the context of electrocardiogram (ECG) signal analysis for diagnoses and predictions with a major application found in heart rate variability parameters. In this article we are combining spatial and temporal PE to form a spatiotemporal PE that captures both, complexity of spatial structures and temporal complexity at the same time. We demonstrate that the spatiotemporal PE (STPE) quantifies complexity using two datasets from simulated cardiac arrhythmia and compare it to phase singularity analysis and spatial PE (SPE). These datasets simulate ventricular fibrillation (VF) on a two-dimensional and a three-dimensional medium using the Fenton-Karma model. We show that SPE and STPE are robust against noise and demonstrate its usefulness for extracting complexity features at different spatial scales."],["dc.identifier.doi","10.3389/fphy.2018.00039"],["dc.identifier.eissn","2296-424X"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/78528"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.publisher","Frontiers Media S.A."],["dc.relation.eissn","2296-424X"],["dc.rights","http://creativecommons.org/licenses/by/4.0/"],["dc.title","Spatiotemporal Permutation Entropy as a Measure for Complexity of Cardiac Arrhythmia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","950"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Entropy"],["dc.bibliographiccitation.lastpage","967"],["dc.bibliographiccitation.volume","17"],["dc.contributor.author","Schlemmer, Alexander"],["dc.contributor.author","Berg, Sebastian"],["dc.contributor.author","Shajahan, T. K."],["dc.contributor.author","Luther, Stefan"],["dc.contributor.author","Parlitz, Ulrich"],["dc.date.accessioned","2018-11-07T10:00:06Z"],["dc.date.available","2018-11-07T10:00:06Z"],["dc.date.issued","2015"],["dc.description.abstract","The characterization of spatiotemporal complexity remains a challenging task. This holds in particular for the analysis of data from fluorescence imaging (optical mapping), which allows for the measurement of membrane potential and intracellular calcium at high spatial and temporal resolutions and, therefore, allows for an investigation of cardiac dynamics. Dominant frequency maps and the analysis of phase singularities are frequently used for this type of excitable media. These methods address some important aspects of cardiac dynamics; however, they only consider very specific properties of excitable media. To extend the scope of the analysis, we present a measure based on entropy rates for determining spatiotemporal complexity patterns of excitable media. Simulated data generated by the Aliev-Panfilov model and the cubic Barkley model are used to validate this method. Then, we apply it to optical mapping data from monolayers of cardiac cells from chicken embryos and compare our findings with dominant frequency maps and the analysis of phase singularities. The studies indicate that entropy rate maps provide additional information about local complexity, the origins of wave breakup and the development of patterns governing unstable wave propagation."],["dc.identifier.doi","10.3390/e17030950"],["dc.identifier.isi","000352612500003"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11891"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37726"],["dc.identifier.url","https://sfb1002.med.uni-goettingen.de/production/literature/publications/83"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/241526/EU//EUTRIGTREAT"],["dc.relation","SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz"],["dc.relation","SFB 1002 | C03: Erholung nach Herzinsuffizienz: Analyse der transmuralen mechano-elektrischen Funktionsstörung"],["dc.relation.issn","1099-4300"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Luther (Biomedical Physics)"],["dc.rights","CC BY 4.0"],["dc.title","Entropy Rate Maps of Complex Excitable Dynamics in Cardiac Monolayers"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]