Berg, Sebastian

[["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","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.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.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"]]