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Sleep Apnea Syndromes: HELP
Articles by Jan F. Kraemer
Based on 5 articles published since 2009
(Why 5 articles?)

Between 2009 and 2019, Jan F. Kraemer wrote the following 5 articles about Sleep Apnea Syndromes.
+ Citations + Abstracts
1 Article Is dynamic desaturation better than a static index to quantify the mortality risk in heart failure patients with Cheyne-Stokes respiration? 2018

Granitza, Philine / Kraemer, Jan F / Schoebel, Christoph / Penzel, Thomas / Kurths, Jürgen / Wessel, Niels. ·Department of Physics, Cardiovascular Physics, Humboldt-Universität zu Berlin, 10099 Berlin, Germany. · Interdisziplinäres Schlafmedizinisches Zentrum, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany. ·Chaos · Pubmed #30384661.

ABSTRACT: Cheyne-Stokes respiration (CSR) is a periodic, highly dynamic, respiratory pattern and a known comorbidity in congestive heart failure (CHF) patients. It is generally seen as an indicator for a negative prognosis, even if no distinction in degree is known or understood. This paper aims to improve on existing attempts by creating a quantification of the behavior of the dynamic desaturation process of oxygen in the blood. We performed this work on a cohort of

2 Article Heart rate variability feature selection in the presence of sleep apnea: An expert system for the characterization and detection of the disorder. 2017

Martín-González, Sofía / Navarro-Mesa, Juan L / Juliá-Serdá, Gabriel / Kraemer, Jan F / Wessel, Niels / Ravelo-García, Antonio G. ·Institute for Technological Development and Innovation in Communications, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria 35017, Spain. Electronic address: sofia.martin@ulpgc.es. · Institute for Technological Development and Innovation in Communications, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria 35017, Spain. · Pulmonary Medicine Department, Hospital Universitario de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, 35010, Spain. · Department of Physics, Humboldt-Universität zu Berlin, Berlin 10115, Germany. ·Comput Biol Med · Pubmed #29040884.

ABSTRACT: We introduce a sleep apnea characterization and classification approach based on a Heart Rate Variability (HRV) feature selection process, thus focusing on the characterization of the underlying process from a cardiac rate point of view. Therefore, we introduce linear and nonlinear variables, namely Cepstrum Coefficients (CC), Filterbanks (Fbank) and Detrended Fluctuation Analysis (DFA). Logistic Regression, Linear Discriminant Analysis and Quadratic Discriminant Analysis were used for classification purposes. The experiments were carried out using two databases. We achieved a per-segment accuracy of 84.76% (sensitivity = 81.45%, specificity = 86.82%, AUC = 0.92) in the Apnea-ECG Physionet database, whereas in the HuGCDN2014 database, provided by the Dr. Negrín University Hospital (Las Palmas de Gran Canaria, Spain), the best results were: accuracy = 81.96%, sensitivity = 70.95%, specificity = 85.47%, AUC = 0.87. The former results were comparable or better than those obtained by other methods for the same database in the recent literature. We have concluded that the selected features that best characterize the underlying process are common to both databases. This supports the fact that the conclusions reached are potentially generalizable. The best results were obtained when the three kinds of features were jointly used. Another notable fact is the small number of features needed to describe the phenomenon. Results suggest that the two first Fbanks, the first CC and the first DFA coefficient are the variables that best describe the RR pattern in OSA and, therefore, are especially relevant to extract discriminative information for apnea screening purposes.

3 Article On the difference of cardiorespiratory synchronisation and coordination. 2017

Krause, Harald / Kraemer, Jan F / Penzel, Thomas / Kurths, Jürgen / Wessel, Niels. ·AG NLD - Cardiovascular Physics, Humboldt-Universität zu Berlin, Berlin, Germany. ·Chaos · Pubmed #28964129.

ABSTRACT: Cardiorespiratory phase synchronisation (CRS) is a type of cardiorespiratory coupling that manifests through a prediliction for heart beats to occur at specific points relative to the phase of the respiratory cycle. It has been under investigation for nearly 20 years, and while it seems to be mostly occurring in relaxed states such as deep sleep and anesthesia, no clear clinical implications have been established. Cardiorespiratory coordination (CRC) is a recent development in this field where the relationship between the respiratory onset and heart beat is analysed in the time domain and the possible relationship of each heart beat is considered for both the previous and the next respiratory onset. This ostensibly closely related effect must not only show relevant information content but also do so independent of CRS in order to be relevant for future studies. In this paper, we investigate CRC and its relation to CRS mainly using graphical and statistical methods on two exemplary datasets: measurements from a pregnant woman participating in a preeclampsia study and those from a man suffering from sleep apnea. We show fundamental differences between the results of both approaches and are able to show a formerly unknown dependency between the heart activity and respiratory rate, potentially indicating heartbeat-initiated inspiration. Despite their differences, methods developed for the quantification of CRS can be adapted to CRC. Completing the comparison is an investigation into the relationship between CRC and respiratory sinus arrhythmia. Similar to previous results for CRS, the two effects are found to be orthogonal, meaning that they can be observed independently or in conjunction.

4 Article Cardio-respiratory coordination increases during sleep apnea. 2014

Riedl, Maik / Müller, Andreas / Kraemer, Jan F / Penzel, Thomas / Kurths, Juergen / Wessel, Niels. ·Cardiovascular Physics, Department of Physics, Humboldt-Universität zu Berlin, Berlin, Germany. · Department for Cardiology, Sleep Medicine Centre, Charité Universitätsmedizin Berlin, Berlin, Germany. · Cardiovascular Physics, Department of Physics, Humboldt-Universität zu Berlin, Berlin, Germany; Research Domain on Transdisciplinary Concepts and Methods, Potsdam Institute for Climate Impact Research, Potsdam, Germany. ·PLoS One · Pubmed #24718564.

ABSTRACT: Cardiovascular diseases are the main source of morbidity and mortality in the United States with costs of more than $170 billion. Repetitive respiratory disorders during sleep are assumed to be a major cause of these diseases. Therefore, the understanding of the cardio-respiratory regulation during these events is of high public interest. One of the governing mechanisms is the mutual influence of the cardiac and respiratory oscillations on their respective onsets, the cardio-respiratory coordination (CRC). We analyze this mechanism based on nocturnal measurements of 27 males suffering from obstructive sleep apnea syndrome. Here we find, by using an advanced analysis technique, the cardiogram, not only that the occurrence of CRC is significantly more frequent during respiratory sleep disturbances than in normal respiration (p-value<10(-51)) but also more frequent after these events (p-value<10(-15)). Especially, the latter finding contradicts the common assumption that spontaneous CRC can only be observed in epochs of relaxed conditions, while our newly discovered epochs of CRC after disturbances are characterized by high autonomic stress. Our findings on the connection between CRC and the appearance of sleep-disordered events require a substantial extension of the current understanding of obstructive sleep apneas and hypopneas.

5 Article Cardiovascular regulation in different sleep stages in the obstructive sleep apnea syndrome. 2011

Gapelyuk, Andrej / Riedl, Maik / Suhrbier, Alexander / Kraemer, Jan F / Bretthauer, Georg / Malberg, Hagen / Kurths, Jürgen / Penzel, Thomas / Wessel, Niels. ·Department of Physics, Humboldt-Universität zu Berlin, Germany. ·Biomed Tech (Berl) · Pubmed #21823997.

ABSTRACT: Heart rate and blood pressure variability analysis as well as baroreflex sensitivity have been proven to be powerful tools for the assessment of autonomic control in clinical practice. Their ability to detect systematic changes caused by different states, diseases and treatments shall be shown for sleep disorders. Therefore, we consider 18 normotensive and 10 hypertensive patients suffering from obstructive sleep apnea syndrome (OSAS) before and after a three-month continuous positive airway pressure (CPAP) therapy. Additionally, an age and sex matched control group of 10 healthy subjects is examined. Linear and nonlinear parameters of heart rate and blood pressure fluctuation as well as the baroreflex sensitivity are used to answer the question whether there are differences in cardiovascular regulation between the different sleep stages and groups. Moreover, the therapeutic effect of CPAP therapy in OSAS patients shall be investigated. Kruskal-Wallis tests between the sleep stages for each group show significant differences in the very low spectral component of heart rate (VLF/P: 0.0033-0.04 Hz, p<0.01) which indicates differences in metabolic activity during the night. Furthermore, the decrease of Shannon entropy of word distribution as a parameter of systolic blood pressure during non-REM sleep reflects the local dominance of the vagal system (p<0.05). The increased sympathetic activation of the patients leads to clear differences of cardiovascular regulation in different sleep stages between controls and patients. We found a significant reduction of baroreflex sensitivity in slow wave sleep in the OSAS patients (Mann-Whitney test, p<0.05) compared to controls, which disappeared after three months of CPAP therapy. Hence, our results demonstrate the ability of cardiovascular analyzes to separate between healthy and pathological regulation as well as between different severities of OSAS in this retrospective study.