PD Dr. rer. nat. Niels Wessel
Profil
Forschungsthemen9
Biosignal 2010 (Veranstaltung: 14.-16.07.2010, Berlin)
Quelle ↗Förderer: DFG sonstige Programme Zeitraum: 04/2010 - 10/2010 Projektleitung: PD Dr. rer. nat. Niels Wessel
CAT-Kongress Biosignal 2010 (Veranstaltung: 14.-16.07.2010, Berlin)
Quelle ↗Zeitraum: 04/2010 - 10/2010 Projektleitung: PD Dr. rer. nat. Niels Wessel
Entwicklung einer Biofeedback-Software zur Beeinflussung der Herzratenvariabilität
Quelle ↗Zeitraum: 12/2012 - 04/2013 Projektleitung: PD Dr. rer. nat. Niels Wessel
Entwicklung von EMG-Biofeedback-Software und Machbarkeitsstudie
Quelle ↗Zeitraum: 09/2013 - 04/2014 Projektleitung: PD Dr. rer. nat. Niels Wessel
Erweitertes Fetalmonitoring mittels systemtechnischer Analyse der fetalen autonomen kardiovaskulären Regulation
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 03/2018 - 03/2022 Projektleitung: PD Dr. rer. nat. Niels Wessel
EXIST-Gruenderstipendium: Mobile Anwendung zur Vorhersage von Mirgraeneattacken
Quelle ↗Förderer: Bundesministerium für Wirtschaft und Energie Zeitraum: 06/2015 - 05/2016 Projektleitung: PD Dr. rer. nat. Niels Wessel
Individualisierte Betrachtung Zirkadianer Rhythmen zur Prävention des plötzlichen Herztodes
Quelle ↗Förderer: Bundesministerium für Forschung, Technologie und Raumfahrt Zeitraum: 12/2018 - 12/2022 Projektleitung: PD Dr. rer. nat. Niels Wessel
Kopplungsanalyse transienter kardiovaskulärer Dynamik
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 03/2012 - 07/2015 Projektleitung: PD Dr. rer. nat. Niels Wessel
Lichtabhängige kardiovaskuläre Regulation bei Konzentration und Schmerz
Quelle ↗Förderer: Bundesministerium für Wirtschaft und Energie Zeitraum: 09/2009 - 08/2012 Projektleitung: PD Dr. rer. nat. Niels Wessel
Mögliche Industrie-Partner10
Stand: 26.4.2026, 19:48:44 (Top-K=20, Min-Cosine=0.4)
NVIDIA GmbH
PT56 Treffer61.5%- EU: Simulation in Multiscale Physical and Biological Systems (STIMULATE)P61.5%
- EU: Simulation in Multiscale Physical and Biological Systems (STIMULATE)
- 56 Treffer61.5%
- EU: Simulation in Multiscale Physical and Biological Systems (STIMULATE)P61.5%
- EU: Simulation in Multiscale Physical and Biological Systems (STIMULATE)
- 58 Treffer61.5%
- EU: Simulation in Multiscale Physical and Biological Systems (STIMULATE)P61.5%
- EU: Bottom-Up Generation of atomicalLy Precise syntheTIc 2D MATerials for High Performance in Energy and Electronic Applications – A Multi-Site Innovative Training Action (ULTIMATE)P47.9%
- EU: Simulation in Multiscale Physical and Biological Systems (STIMULATE)
- 5 Treffer59.6%
- Gamification for Climate ActionP59.6%
- Gamification for Climate Action
- 7 Treffer58.9%
- Zuwendung im Rahmen des Programms „exist – Existenzgründungen aus der Wissenschaft“ aus dem Bundeshaushalt, Einzelplan 09, Kapitel 02, Titel 68607, Haushaltsjahr 2026, sowie aus Mitteln des Europäischen Strukturfonds (hier Euro-päischer Sozialfonds Plus – ESF Plus) Förderperiode 2021-2027 – Kofinanzierung für das Vorhaben: „exist Women“T58.9%
- Zuwendung im Rahmen des Programms „exist – Existenzgründungen aus der Wissenschaft“ aus dem Bundeshaushalt, Einzelplan 09, Kapitel 02, Titel 68607, Haushaltsjahr 2026, sowie aus Mitteln des Europäischen Strukturfonds (hier Euro-päischer Sozialfonds Plus – ESF Plus) Förderperiode 2021-2027 – Kofinanzierung für das Vorhaben: „exist Women“
- 19 Treffer58.7%
- Workshop Reliable Methods and Mathematical ModelingP58.7%
- Workshop Reliable Methods and Mathematical Modeling
- 36 Treffer55.1%
- Systematic Models for Biological Systems Engineering Training NetworkP55.1%
- Systematic Models for Biological Systems Engineering Training Network
Protatuans-Etaireia Ereynas Viotechologias Monoprosopi Etaireia Periorisments Eythinis
PT33 Treffer55.1%- Systematic Models for Biological Systems Engineering Training NetworkP55.1%
- Systematic Models for Biological Systems Engineering Training Network
- 39 Treffer55.1%
- Systematic Models for Biological Systems Engineering Training NetworkP55.1%
- Systematic Models for Biological Systems Engineering Training Network
- 38 Treffer55.1%
- Systematic Models for Biological Systems Engineering Training NetworkP55.1%
- Systematic Models for Biological Systems Engineering Training Network
Publikationen25
Top 25 nach Zitationen — Quelle: OpenAlex (BAAI/bge-m3 embedded für Matching).
Recurrence-plot-based measures of complexity and their application to heart-rate-variability data
2002Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · 976 Zitationen · DOI
The knowledge of transitions between regular, laminar or chaotic behaviors is essential to understand the underlying mechanisms behind complex systems. While several linear approaches are often insufficient to describe such processes, there are several nonlinear methods that, however, require rather long time observations. To overcome these difficulties, we propose measures of complexity based on vertical structures in recurrence plots and apply them to the logistic map as well as to heart-rate-variability data. For the logistic map these measures enable us not only to detect transitions between chaotic and periodic states, but also to identify laminar states, i.e., chaos-chaos transitions. The traditional recurrence quantification analysis fails to detect the latter transitions. Applying our measures to the heart-rate-variability data, we are able to detect and quantify the laminar phases before a life-threatening cardiac arrhythmia occurs thereby facilitating a prediction of such an event. Our findings could be of importance for the therapy of malignant cardiac arrhythmias.
Chaos An Interdisciplinary Journal of Nonlinear Science · 476 Zitationen · DOI
In the modern industrialized countries every year several hundred thousands of people die due to sudden cardiac death. The individual risk for this sudden cardiac death cannot be defined precisely by common available, noninvasive diagnostic tools like Holter monitoring, highly amplified ECG and traditional linear analysis of heart rate variability (HRV). Therefore, we apply some rather unconventional methods of nonlinear dynamics to analyze the HRV. Especially, some complexity measures that are based on symbolic dynamics as well as a new measure, the renormalized entropy, detect some abnormalities in the HRV of several patients who have been classified in the low risk group by traditional methods. A combination of these complexity measures with the parameters in the frequency domain seems to be a promising way to get a more precise definition of the individual risk. These findings have to be validated by a representative number of patients. (c) 1995 American Institute of Physics.
Cardiovascular Research · 446 Zitationen · DOI
The methods of NLD describe complex rhythm fluctuations and separate structures of non-linear behavior in the heart rate time series more successfully than classical methods of time and frequency domains. This leads to an improved discrimination between a normal (healthy persons) and an abnormal (high risk patients) type of heart beat generation. Some patients with an unknown risk exhibit similar patterns to high risk patients and this suggests a hidden high risk. The methods of symbolic dynamics and renormalized entropy were particularly useful measures for classifying the dynamics of HRV.
The European Physical Journal Special Topics · 333 Zitationen · DOI
Herzschrittmachertherapie + Elektrophysiologie · 287 Zitationen · DOI
Hypertension · 238 Zitationen · DOI
Angiogenic factors like placental growth factor and its antiangiogenic antagonist soluble fms-like tyrosine kinase 1 (sFlt1) are closely related to the pathogenesis of preeclampsia and intrauterine growth restriction. Because it is known that altered maternal sFlt1 and placental growth factor levels are detectable weeks before the onset of these pregnancy complications, it was the aim of the study to investigate the predictive value of these markers in high-risk second trimester pregnancies characterized by abnormal uterine perfusion. This prospective study includes 63 second trimester pregnant women with abnormal uterine perfusion. Twenty five of them developed a later complication (12 with preeclampsia, 11 with intrauterine growth restriction, and 2 with intrauterine death), whereas 38 had a normal course of pregnancy. Pregnancies with adverse pregnancy outcome showed in the second trimester significantly higher sFlt1 (1403.6+/-555 versus 451.8+/-42 pg/mL; P<0.05) and lower placental growth factor (139.6+/-24 versus 184.1+/-21 pg/mL) levels compared with those with normal outcome. These alterations were more pronounced in pregnancies with subsequent preeclampsia compared with intrauterine growth restriction and early onset diseases (delivery <34 weeks) compared with late-onset diseases. The combination of Doppler and sFlt1 increases the sensitivity of Doppler alone for iatrogenic preterm delivery from 64% up to 79% and the specificity from 63% up to 80%. Using both factors, sFlt1 and placental growth factor, early onset preeclampsia can be predicted with 83% sensitivity and 95% specificity. We conclude that the concurrent measurement of uterine perfusion and angiogenic factors allows an efficient prediction of early onset pregnancy complications, particularly preeclampsia.
Computers in Biology and Medicine · 219 Zitationen · DOI
Journal of Lipid Research · 218 Zitationen · DOI
Cytochrome P450 (CYP)-dependent metabolites of arachidonic acid (AA) contribute to the regulation of cardiovascular function. CYP enzymes also accept EPA and DHA to yield more potent vasodilatory and potentially anti-arrhythmic metabolites, suggesting that the endogenous CYP-eicosanoid profile can be favorably shifted by dietary omega-3 fatty acids. To test this hypothesis, 20 healthy volunteers were treated with an EPA/DHA supplement and analyzed for concomitant changes in the circulatory and urinary levels of AA-, EPA-, and DHA-derived metabolites produced by the cyclooxygenase-, lipoxygenase (LOX)-, and CYP-dependent pathways. Raising the Omega-3 Index from about four to eight primarily resulted in a large increase of EPA-derived CYP-dependent epoxy-metabolites followed by increases of EPA- and DHA-derived LOX-dependent monohydroxy-metabolites including the precursors of the resolvin E and D families; resolvins themselves were not detected. The metabolite/precursor fatty acid ratios indicated that CYP epoxygenases metabolized EPA with an 8.6-fold higher efficiency and DHA with a 2.2-fold higher efficiency than AA. Effects on leukotriene, prostaglandin E, prostacyclin, and thromboxane formation remained rather weak. We propose that CYP-dependent epoxy-metabolites of EPA and DHA may function as mediators of the vasodilatory and cardioprotective effects of omega-3 fatty acids and could serve as biomarkers in clinical studies investigating the cardiovascular effects of EPA/DHA supplementation.
Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · 180 Zitationen · DOI
Ventricular tachycardia or fibrillation (VT-VF) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this study is to find early signs of sustained VT-VF in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they store the 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 17 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e., without a VT-VF event. To characterize these rather short data sets, we calculate heart rate variability parameters from the time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that neither the time nor the frequency domain parameters show significant differences between the VT-VF and the control time series. However, two parameters from symbolic dynamics as well as the finite-time growth rates discriminate significantly both groups. These findings could be of importance in algorithms for next generation ICD's to improve the diagnostics and therapy of VT-VF.
Frontiers in Physiology · 167 Zitationen · DOI
The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave).
Proceedings of the National Academy of Sciences · 137 Zitationen · DOI
Pregnant mothers often report a special awareness of and bonding with their unborn child. Little is known about this relationship although it may offer potential for the assessment of the fetal condition. Recently we found evidence of short epochs of fetal-maternal heart rate synchronization under uncontrolled conditions with spontaneous maternal breathing. Here, we examine whether the occurrence of such epochs can be influenced by maternal respiratory arrhythmia induced by paced breathing at several different rates (10, 12, 15, and 20 cycles per minute). To test for such weak and nonstationary synchronizations among the fetal-maternal subsystems, we apply a multivariate synchronization analysis technique and test statistics based on twin surrogates. We find a clear increase in synchronization epochs mostly at high maternal respiratory rates in the original but not in the surrogate data. On the other hand, fewer epochs are found at low respiratory rates both in original and surrogate data. The results suggest that the fetal cardiac system seems to possess the capability to adjust its rate of activation in response to external--i.e., maternal--stimulation. Hence, the pregnant mothers' special awareness to the unborn child may also be reflected by fetal-maternal interaction of cardiac activity. Our approach opens up the chance to examine this interaction between independent but closely linked physiological systems.
Methods of Information in Medicine · 125 Zitationen · DOI
Compression entropy might be a suitable parameter for short-term forecasting of life-threatening tachycardia in ICD.
American Journal of Obstetrics and Gynecology · 119 Zitationen · DOI
International Journal of Bifurcation and Chaos · 109 Zitationen · DOI
In this tutorial we present recently developed nonlinear methods of cardiovascular physics and show their potentials to clinically relevant problems in cardiology. The first part describes methods of cardiovascular physics, especially data analysis and modeling of noninvasively measured biosignals, with the aim to improve clinical diagnostics and to improve the understanding of cardiovascular regulation. Applications of nonlinear data analysis and modeling tools are various and outlined in the second part of this tutorial: monitoring-, diagnosis-, course and mortality prognoses as well as early detection of heart diseases. We show, that these data analyses and modeling methods lead to significant improvements in different medical fields.
American Journal of Hypertension · 109 Zitationen · DOI
Heart rate variability is a relevant predictor of cardiovascular risk in humans. However, to use heart and blood pressure (BP) variability or baroreflex sensitivity as markers for hypertensive pregnancy disorders, it is first necessary to describe these parameters in normal pregnancy. To accommodate the complexities of autonomic cardiovascular control we added parameter domains of nonlinear dynamics to conventional linear methods of time and frequency domains. The BP of 27 women with normal pregnancy and 14 nonpregnant women were monitored at a high resolution (200 Hz sampling frequency) using a Portapres for 30 min. The pregnant women were divided into groups of 32 or less or greater than 32 weeks of gestation. Pregnant and nonpregnant women were classified into subclasses of maternal age of less than 28 or 28 or more years. Except for two single parameter domains, we found no significant differences in heart rate and BP variability for pregnant women with different gestational age or different maternal age. Moreover, no significant differences in spontaneous baroreflex sensitivity could be found between pregnant women regardless of either their age or gestational age. In contrast, all measures of nonlinear dynamics of heart rate variability as well as all parameter domains of spontaneous baroreflex sensitivity showed significant changes between pregnant and nonpregnant women, whereas BP variability did not differ between those groups. This complex assessment of autonomic cardiovascular regulation has shown that the parameters tested are stable in the second half of normal pregnancy, and might have the potential to be excellent indicators of pathophysiologic conditions.
Pacing and Clinical Electrophysiology · 106 Zitationen · DOI
A multiparametric heart rate variability analysis was performed to prove if combined heart rate variability (HRV) measures of different domains improve the result of risk stratification in patients after myocardial infarction. In this study, standard time domain, frequency domain and non-linear dynamics measures of HRV assessment were applied to 572 survivors of acute myocardial infarction. Three parameter sets each consisting of 4 parameters were applied and compared with the standard measurement of global heart rate variability HRVi. Discriminant analysis technique and t-test were performed to separate the high risk groups from the survivors. The predictive value of this approach was evaluated with receiver operator (ROC) and positive predictive accuracy (PPA) curves. Results--The discriminant analysis shows a separation of patients suffered by all cause mortality in 80% (best single parameter 74%) and sudden arrhythmic death in 86% (73%). All parameters of set 1 show a high significant difference (p < 0.001) between survivors and non-survivors based on two-tailed t-test. The specificity level of the multivariate parameter sets is at the 70% sensitivity level (ROC) about 85-90%, whereas HRVi shows maximum levels of 70%. The PPA in the all cause mortality group is at the 70% sensitivity level twice as high as the univariate HRV measure and increases to more than fourfold as high within the VT/VF group. In conclusion, in this population, the multiparametric approach with the combination of four parameters from all domains especially from NLD seems to be a better predictor of high arrhythmia risk than the standard measurement of global heart rate variability.
Physiological Measurement · 105 Zitationen · DOI
The fetal ECG derived from abdominal leads provides an alternative to standard means of fetal monitoring. Furthermore, it permits long-term and ambulant recordings, which expands the range diagnostic possibilities for evaluating the fetal health state. However, due to the temporal and spectral overlap of maternal and fetal signals, the usage of abdominal leads imposes the need for elaborated signal processing routines.In this work a modular combination of processing techniques is presented. Its core consists of two maternal ECG estimation techniques, namely the extended Kalman smoother (EKS) and template adaption (TA) in combination with an innovative detection algorithm. Our detection method employs principles of evolutionary computing to detect fetal peaks by considering the periodicity and morphological characteristics of the fetal signal. In a postprocessing phase, single channel detections are combined by means of kernel density estimation and heart rate correction.The described methodology was presented during the Computing in Cardiology Challenge 2013. The entry was the winner of the closed-source events with average scores for events 4/5 with 15.1/3.32 (TA) and 69.5/4.58 (EKS) on training set-A and 20.4/4.57 (TA) and 219/7.69 (EKS) on test set-B, respectively. Using our own clinical data (24 subjects each 20 min recordings) and statistical measures beyond the Challenge's scoring system, we further validated the proposed method. For our clinical data we obtained an average detection rate of 82.8% (TA) and 83.4% (EKS). The achieved results show that the proposed methods are able produce reliable fetal heart rate estimates from a restricted number of abdominal leads.
The American Journal of Cardiology · 81 Zitationen · DOI
Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences · 76 Zitationen · DOI
Correlation dimension analysis of heart rate variability in patients with dilated cardiomyopathy
2005Computer Methods and Programs in Biomedicine · 75 Zitationen · DOI
The European Physical Journal Special Topics · 73 Zitationen · DOI
Journal of Electrocardiology · 73 Zitationen · DOI
Journal of Human Hypertension · 72 Zitationen · DOI
Chaos An Interdisciplinary Journal of Nonlinear Science · 69 Zitationen · DOI
The incidence of cardiovascular diseases increases with the growth of the human population and an aging society, leading to very high expenses in the public health system. Therefore, it is challenging to develop sophisticated methods in order to improve medical diagnostics. The question whether the normal heart rate is chaotic or not is an attempt to elucidate the underlying mechanisms of cardiovascular dynamics and therefore a highly controversial topical challenge. In this contribution we demonstrate that linear and nonlinear parameters allow us to separate completely the data sets of the three groups provided for this controversial topic in nonlinear dynamics. The question whether these time series are chaotic or not cannot be answered satisfactorily without investigating the underlying mechanisms leading to them. We give an example of the dominant influence of respiration on heart beat dynamics, which shows that observed fluctuations can be mostly explained by respiratory modulations of heart rate and blood pressure (coefficient of determination: 96%). Therefore, we recommend reformulating the following initial question: "Is the normal heart rate chaotic?" We rather ask the following: "Is the normal heart rate 'chaotic' due to respiration?"
Chaos An Interdisciplinary Journal of Nonlinear Science · 69 Zitationen · DOI
Sleep is an active and regulated process with restorative functions for physical and mental conditions. Based on recordings of brain waves and the analysis of characteristic patterns and waveforms it is possible to distinguish wakefulness and five sleep stages. Sleep and the sleep stages modulate autonomous nervous system functions such as body temperature, respiration, blood pressure, and heart rate. These functions consist of a sympathetic tone usually related to activation and to parasympathetic (or vagal) tone usually related to inhibition. Methods of statistical physics are used to analyze heart rate and respiration to detect changes of the autonomous nervous system during sleep. Detrended fluctuation analysis and synchronization analysis and their applications to heart rate and respiration during sleep in healthy subjects and patients with sleep disorders are presented. The observed changes can be used to distinguish sleep stages in healthy subjects as well as to differentiate normal and disturbed sleep on the basis of heart rate and respiration recordings without direct recording of brain waves. Of special interest are the cardiovascular consequences of disturbed sleep because they present a risk factor for cardiovascular disorders such as arterial hypertension, cardiac ischemia, sudden cardiac death, and stroke. New derived variables can help to find indicators for these health risks.
Kooperationen0
Bestätigte Forscher↔Partner-Paare aus HU-FIS — Gold-Standard-Positive für das Matching.
Aus HU-FIS sind keine Kooperationen für diese Person gemeldet.
Stammdaten
Identität, Organisation und Kontakt aus HU-FIS.
- Name
- PD Dr. rer. nat. Niels Wessel
- Titel
- PD Dr. rer. nat.
- Fakultät
- Mathematisch-Naturwissenschaftliche Fakultät
- Institut
- Institut für Physik
- Arbeitsgruppe
- Nichtlineare Dynamik (S)
- Telefon
- +49 30 2093-99181
- HU-FIS-Profil
- Quelle ↗
- Zuletzt gescrapt
- 26.4.2026, 01:14:04