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Barnes SJK, Bjerkan J, Clemson PT, Newman J, Stefanovska A. Phase coherence-A time-localized approach to studying interactions. CHAOS (WOODBURY, N.Y.) 2024; 34:073155. [PMID: 39052926 DOI: 10.1063/5.0202865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 06/13/2024] [Indexed: 07/27/2024]
Abstract
Coherence measures the similarity of progression of phases between oscillations or waves. When applied to multi-scale, nonstationary dynamics with time-varying amplitudes and frequencies, high values of coherence provide a useful indication of interactions, which might otherwise go unnoticed. However, the choice of analyzing coherence based on phases and amplitudes (amplitude-weighted phase coherence) vs only phases (phase coherence) has long been seen as arbitrary. Here, we review the concept of coherence and focus on time-localized methods of analysis, considering both phase coherence and amplitude-weighted phase coherence. We discuss the importance of using time-localized analysis and illustrate the methods and their practicalities on both numerically modeled and real time-series. The results show that phase coherence is more robust than amplitude-weighted phase coherence to both noise perturbations and movement artifacts. The results also have wider implications for the analysis of real data and the interpretation of physical systems.
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Affiliation(s)
- S J K Barnes
- Physics Department, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - J Bjerkan
- Physics Department, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - P T Clemson
- Physics Department, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - J Newman
- Department of Mathematics and Statistics, University of Exeter, Exeter, United Kingdom
| | - A Stefanovska
- Physics Department, Lancaster University, Lancaster LA1 4YB, United Kingdom
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2
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Skytioti M, Wiedmann M, Sorteberg A, Romundstad L, Hassan Ali Y, Mohammad Ayoubi A, Zilakos I, Elstad M. Dynamic cerebral autoregulation is preserved during orthostasis and intrathoracic pressure regulation in healthy subjects: A pilot study. Physiol Rep 2024; 12:e16027. [PMID: 38684421 PMCID: PMC11058003 DOI: 10.14814/phy2.16027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 05/02/2024] Open
Abstract
Resistance breathing may restore cardiac output (CO) and cerebral blood flow (CBF) during hypovolemia. We assessed CBF and cerebral autoregulation (CA) during tilt, resistance breathing, and paced breathing in 10 healthy subjects. Blood velocities in the internal carotid artery (ICA), middle cerebral arteries (MCA, four subjects), and aorta were measured by Doppler ultrasound in 30° and 60° semi-recumbent positions. ICA blood flow and CO were calculated. Arterial blood pressure (ABP, Finometer), and end-tidal CO2 (ETCO2) were recorded. ICA blood flow response was assessed by mixed-models regression analysis. The synchronization index (SI) for the variable pairs ABP-ICA blood velocity, ABP-MCA velocities in 0.005-0.08 Hz frequency interval was calculated as a measure of CA. Passive tilting from 30° to 60° resulted in 12% decrease in CO (p = 0.001); ICA blood flow tended to fall (p = 0.04); Resistance breathing restored CO and ICA blood flow despite a 10% ETCO2 drop. ETCO2 and CO contributed to ICA blood flow variance (adjusted R2: 0.9, p < 0.0001). The median SI was low (<0.2) indicating intact CA, confirmed by surrogate date testing. The peak SI was transiently elevated during resistance breathing in the 60° position. Resistance breathing may transiently reduce CA efficiency. Paced breathing did not restore CO or ICA blood flow.
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Affiliation(s)
- M. Skytioti
- Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
- Department of AnesthesiologyOslo University HospitalOsloNorway
| | - M. Wiedmann
- Department of NeurosurgeryOslo University HospitalOsloNorway
| | - A. Sorteberg
- Department of NeurosurgeryOslo University HospitalOsloNorway
| | - L. Romundstad
- Department of AnesthesiologyOslo University HospitalOsloNorway
| | - Y. Hassan Ali
- Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | - A. Mohammad Ayoubi
- Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
| | | | - M. Elstad
- Department of Molecular Medicine, Institute of Basic Medical SciencesUniversity of OsloOsloNorway
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3
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Keshmiri S, Tomonaga S, Mizutani H, Doya K. Respiratory modulation of the heart rate: A potential biomarker of cardiorespiratory function in human. Comput Biol Med 2024; 173:108335. [PMID: 38564855 DOI: 10.1016/j.compbiomed.2024.108335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/07/2024] [Accepted: 03/17/2024] [Indexed: 04/04/2024]
Abstract
In recent decade, wearable digital devices have shown potentials for the discovery of novel biomarkers of humans' physiology and behavior. Heart rate (HR) and respiration rate (RR) are most crucial bio-signals in humans' digital phenotyping research. HR is a continuous and non-invasive proxy to autonomic nervous system and ample evidence pinpoints the critical role of respiratory modulation of cardiac function. In the present study, we recorded longitudinal (7 days, 4.63 ± 1.52) HR and RR of 89 freely behaving human subjects (Female: 39, age 57.28 ± 5.67, Male: 50, age 58.48 ± 6.32) and analyzed their dynamics using linear models and information theoretic measures. While HR's linear and nonlinear characteristics were expressed within the plane of the HR-RR directed flow of information (HR→RR - RR→HR), their dynamics were determined by its RR→HR axis. More importantly, RR→HR quantified the effect of alcohol consumption on individuals' cardiorespiratory function independent of their consumed amount of alcohol, thereby signifying the presence of this habit in their daily life activities. The present findings provided evidence for the critical role of the respiratory modulation of HR, which was previously only studied in non-human animals. These results can contribute to humans' phenotyping research by presenting RR→HR as a digital diagnosis/prognosis marker of humans' cardiorespiratory pathology.
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Affiliation(s)
- Soheil Keshmiri
- Optical Neuroimaging Unit, Okinawa Institute of Science and Technology, Okinawa, Japan.
| | - Sutashu Tomonaga
- Neural Computation Unit (NCU), Okinawa Institute of Science and Technology, Okinawa, Japan.
| | - Haruo Mizutani
- Suntory Global Innovation Center Limited (SGIC), Suntory, Kyoto, Japan.
| | - Kenji Doya
- Neural Computation Unit (NCU), Okinawa Institute of Science and Technology, Okinawa, Japan.
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4
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Ma YJX, Zschocke J, Glos M, Kluge M, Penzel T, Kantelhardt JW, Bartsch RP. Sleep-stage dependence and co-existence of cardio-respiratory coordination and phase synchronization. CHAOS (WOODBURY, N.Y.) 2024; 34:043118. [PMID: 38572945 DOI: 10.1063/5.0177552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 03/13/2024] [Indexed: 04/05/2024]
Abstract
Interactions between the cardiac and respiratory systems play a pivotal role in physiological functioning. Nonetheless, the intricacies of cardio-respiratory couplings, such as cardio-respiratory phase synchronization (CRPS) and cardio-respiratory coordination (CRC), remain elusive, and an automated algorithm for CRC detection is lacking. This paper introduces an automated CRC detection algorithm, which allowed us to conduct a comprehensive comparison of CRPS and CRC during sleep for the first time using an extensive database. We found that CRPS is more sensitive to sleep-stage transitions, and intriguingly, there is a negative correlation between the degree of CRPS and CRC when fluctuations in breathing frequency are high. This comparative analysis holds promise in assisting researchers in gaining deeper insights into the mechanics of and distinctions between these two physiological phenomena. Additionally, the automated algorithms we devised have the potential to offer valuable insights into the clinical applications of CRC and CRPS.
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Affiliation(s)
- Yaopeng J X Ma
- Department of Physics, Bar-Ilan University, 5290002 Ramat Gan, Israel
| | - Johannes Zschocke
- Institute of Medical Epidemiology, Biometrics and Informatics (IMEBI), Interdisciplinary Center for Health Sciences, Martin-Luther-University Halle-Wittenberg, 06097 Halle (Saale), Germany
- Institute of Physics, Martin-Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
| | - Martin Glos
- Interdisciplinary Center for Sleep Medicine, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Maria Kluge
- Interdisciplinary Center for Sleep Medicine, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Thomas Penzel
- Interdisciplinary Center for Sleep Medicine, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Jan W Kantelhardt
- Institute of Physics, Martin-Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
| | - Ronny P Bartsch
- Department of Physics, Bar-Ilan University, 5290002 Ramat Gan, Israel
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Zhang J, Li W, Zhang K, Huo C, Xu G, Li Z. Blood pressure-cerebral oxygen coupling model: A new approach for stroke risk prediction. JOURNAL OF BIOPHOTONICS 2024; 17:e202300318. [PMID: 37795638 DOI: 10.1002/jbio.202300318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/11/2023] [Accepted: 10/04/2023] [Indexed: 10/06/2023]
Abstract
Stroke is a major cause of death and disability worldwide, but predicting its risk remains challenging. This study aimed to evaluate the cerebral blood flow autoregulation function of subjects with different stroke risk levels and predict their stroke risk. The coupling strength between cerebral oxygen and blood pressure signals was calculated by wavelet analysis and dynamic Bayesian inference and used as a quantitative index of cerebral blood flow autoregulation. A stroke prediction model based on the extreme random tree was constructed using the coupling strength and other data as input features. The results showed that the coupling strength was significantly higher in the high-risk group than the other groups. Moreover, the prediction model achieved an average accuracy of 0.80 across the three groups. The coupling strength of cerebral oxygen and blood pressure can be used as an objective index to predict stroke risk, which has implications for stroke prevention and intervention.
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Affiliation(s)
- Jingsha Zhang
- Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Center for Rehabilitation Technical Aids, Beijing, China
- Key Laboratory of Neuro-Functional Information and Rehabilitation Engineering of the Ministry of Civil Affairs, Beijing, China
| | - Wenhao Li
- School of Rehabilitation Engineering, Beijing College of Social Administration, Beijing, China
| | - Ke Zhang
- Nanchang City Key Laboratory of Integrated Medical and Industrial Technology, Nanchang University, Nanchang, China
| | - Congcong Huo
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Gongcheng Xu
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Zengyong Li
- Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Center for Rehabilitation Technical Aids, Beijing, China
- Key Laboratory of Neuro-Functional Information and Rehabilitation Engineering of the Ministry of Civil Affairs, Beijing, China
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Bester M, Perciballi G, Fonseca P, van Gilst MM, Mischi M, van Laar JO, Vullings R, Joshi R. Maternal cardiorespiratory coupling: differences between pregnant and nonpregnant women are further amplified by sleep-stage stratification. J Appl Physiol (1985) 2023; 135:1199-1212. [PMID: 37767554 PMCID: PMC10979799 DOI: 10.1152/japplphysiol.00296.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/22/2023] [Accepted: 09/22/2023] [Indexed: 09/29/2023] Open
Abstract
Pregnancy complications are associated with abnormal maternal autonomic regulation. Subsequently, thoroughly understanding maternal autonomic regulation during healthy pregnancy may enable the earlier detection of complications, in turn allowing for the improved management thereof. Under healthy autonomic regulation, reciprocal interactions occur between the cardiac and respiratory systems, i.e., cardiorespiratory coupling (CRC). Here, we investigate, for the first time, the differences in CRC between healthy pregnant and nonpregnant women. We apply two algorithms, namely, synchrograms and bivariate phase-rectified signal averaging, to nighttime recordings of ECG and respiratory signals. We find that CRC is present in both groups. Significantly less (P < 0.01) cardiorespiratory synchronization occurs in pregnant women (11% vs. 15% in nonpregnant women). Moreover, there is a smaller response in the heart rate of pregnant women corresponding to respiratory inhalations and exhalations. In addition, we stratified these analyses by sleep stages. As each sleep stage is governed by different autonomic states, this stratification not only amplified some of the differences between groups but also brought out differences that remained hidden when analyzing the full-night recordings. Most notably, the known positive relationship between CRC and deep sleep is less prominent in pregnant women than in their nonpregnant counterparts. The decrease in CRC during healthy pregnancy may be attributable to decreased maternal parasympathetic activity, anatomical changes to the maternal respiratory system, and the increased physiological stress accompanying pregnancy. This work offers novel insight into the physiology of healthy pregnancy and forms part of the base knowledge needed to detect abnormalities in pregnancy.NEW & NOTEWORTHY We compare CRC, i.e., the reciprocal interaction between the cardiac and respiratory systems, between healthy pregnant and nonpregnant women for the first time. Although CRC is present in both groups, CRC is reduced during healthy pregnancy; there is less synchronization between maternal cardiac and respiratory activity and a smaller response in maternal heart rate to respiratory inhalations and exhalations. Stratifying this analysis by sleep stages reveals that differences are most prominent during deep sleep.
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Affiliation(s)
- Maretha Bester
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Patient Care and Monitoring, Philips Research, Eindhoven, The Netherlands
| | - Giulia Perciballi
- Patient Care and Monitoring, Philips Research, Eindhoven, The Netherlands
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Pedro Fonseca
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Patient Care and Monitoring, Philips Research, Eindhoven, The Netherlands
| | - Merel M van Gilst
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Sleep Medicine Center Kempenhaeghe, Heeze, The Netherlands
| | - Massimo Mischi
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Judith Oeh van Laar
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Department of Obstetrics and Gynecology, Máxima Medical Centrum, Veldhoven, The Netherlands
| | - Rik Vullings
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rohan Joshi
- Patient Care and Monitoring, Philips Research, Eindhoven, The Netherlands
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7
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Lukarski D, Petkoski S, Ji P, Stankovski T. Delta-alpha cross-frequency coupling for different brain regions. CHAOS (WOODBURY, N.Y.) 2023; 33:103126. [PMID: 37844293 DOI: 10.1063/5.0157979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 09/26/2023] [Indexed: 10/18/2023]
Abstract
Neural interactions occur on different levels and scales. It is of particular importance to understand how they are distributed among different neuroanatomical and physiological relevant brain regions. We investigated neural cross-frequency couplings between different brain regions according to the Desikan-Killiany brain parcellation. The adaptive dynamic Bayesian inference method was applied to EEG measurements of healthy resting subjects in order to reconstruct the coupling functions. It was found that even after averaging over all subjects, the mean coupling function showed a characteristic waveform, confirming the direct influence of the delta-phase on the alpha-phase dynamics in certain brain regions and that the shape of the coupling function changes for different regions. While the averaged coupling function within a region was of similar form, the region-averaged coupling function was averaged out, which implies that there is a common dependence within separate regions across the subjects. It was also found that for certain regions the influence of delta on alpha oscillations is more pronounced and that oscillations that influence other are more evenly distributed across brain regions than the influenced oscillations. When presenting the information on brain lobes, it was shown that the influence of delta emanating from the brain as a whole is greatest on the alpha oscillations of the cingulate frontal lobe, and at the same time the influence of delta from the cingulate parietal brain lobe is greatest on the alpha oscillations of the whole brain.
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Affiliation(s)
- Dushko Lukarski
- Faculty of Medicine, Ss. Cyril and Methodius University, 1000 Skopje, Macedonia
- University Clinic for Radiotherapy and Oncology, 1000 Skopje, Macedonia
| | - Spase Petkoski
- Aix Marseille Univ, INSERM, Inst Neurosci Syst (INS), 13005 Marseille, France
| | - Peng Ji
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, 200433 Shanghai, China
| | - Tomislav Stankovski
- Faculty of Medicine, Ss. Cyril and Methodius University, 1000 Skopje, Macedonia
- Department of Physics, Lancaster University, LA1 4YB Lancaster, United Kingdom
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8
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Mircheski P, Zhu J, Nakao H. Phase-amplitude reduction and optimal phase locking of collectively oscillating networks. CHAOS (WOODBURY, N.Y.) 2023; 33:103111. [PMID: 37831791 DOI: 10.1063/5.0161119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 09/13/2023] [Indexed: 10/15/2023]
Abstract
We present a phase-amplitude reduction framework for analyzing collective oscillations in networked dynamical systems. The framework, which builds on the phase reduction method, takes into account not only the collective dynamics on the limit cycle but also deviations from it by introducing amplitude variables and using them with the phase variable. The framework allows us to study how networks react to applied inputs or coupling, including their synchronization and phase locking, while capturing the deviations of the network states from the unperturbed dynamics. Numerical simulations are used to demonstrate the effectiveness of the framework for networks composed of FitzHugh-Nagumo elements. The resulting phase-amplitude equations can be used in deriving optimal periodic waveforms or introducing feedback control for achieving fast phase locking while stabilizing the collective oscillations.
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Affiliation(s)
- Petar Mircheski
- Department of Systems and Control Engineering, Tokyo Institute of Technology, Tokyo 152-8552, Japan
| | - Jinjie Zhu
- State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Hiroya Nakao
- Department of Systems and Control Engineering, Tokyo Institute of Technology, Tokyo 152-8552, Japan
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9
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Platiša MM, Radovanović NN, Pernice R, Barà C, Pavlović SU, Faes L. Information-Theoretic Analysis of Cardio-Respiratory Interactions in Heart Failure Patients: Effects of Arrhythmias and Cardiac Resynchronization Therapy. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1072. [PMID: 37510019 PMCID: PMC10378632 DOI: 10.3390/e25071072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023]
Abstract
The properties of cardio-respiratory coupling (CRC) are affected by various pathological conditions related to the cardiovascular and/or respiratory systems. In heart failure, one of the most common cardiac pathological conditions, the degree of CRC changes primarily depend on the type of heart-rhythm alterations. In this work, we investigated CRC in heart-failure patients, applying measures from information theory, i.e., Granger Causality (GC), Transfer Entropy (TE) and Cross Entropy (CE), to quantify the directed coupling and causality between cardiac (RR interval) and respiratory (Resp) time series. Patients were divided into three groups depending on their heart rhythm (sinus rhythm and presence of low/high number of ventricular extrasystoles) and were studied also after cardiac resynchronization therapy (CRT), distinguishing responders and non-responders to the therapy. The information-theoretic analysis of bidirectional cardio-respiratory interactions in HF patients revealed the strong effect of nonlinear components in the RR (high number of ventricular extrasystoles) and in the Resp time series (respiratory sinus arrhythmia) as well as in their causal interactions. We showed that GC as a linear model measure is not sensitive to both nonlinear components and only model free measures as TE and CE may quantify them. CRT responders mainly exhibit unchanged asymmetry in the TE values, with statistically significant dominance of the information flow from Resp to RR over the opposite flow from RR to Resp, before and after CRT. In non-responders this asymmetry was statistically significant only after CRT. Our results indicate that the success of CRT is related to corresponding information transfer between the cardiac and respiratory signal quantified at baseline measurements, which could contribute to a better selection of patients for this type of therapy.
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Affiliation(s)
- Mirjana M Platiša
- Laboratory for Biosignals, Institute of Biophysics, Faculty of Medicine, University of Belgrade, Višegradska 26-2, 11000 Belgrade, Serbia
| | - Nikola N Radovanović
- Pacemaker Center, University Clinical Center of Serbia, University of Belgrade, 11000 Belgrade, Serbia
| | - Riccardo Pernice
- Department of Engineering, University of Palermo, Viale delle Scienze, Building 9, 90128 Palermo, Italy
| | - Chiara Barà
- Department of Engineering, University of Palermo, Viale delle Scienze, Building 9, 90128 Palermo, Italy
| | - Siniša U Pavlović
- Pacemaker Center, University Clinical Center of Serbia, University of Belgrade, 11000 Belgrade, Serbia
| | - Luca Faes
- Department of Engineering, University of Palermo, Viale delle Scienze, Building 9, 90128 Palermo, Italy
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Cardiorespiratory coupling in mechanically ventilated patients studied via synchrogram analysis. Med Biol Eng Comput 2023; 61:1329-1341. [PMID: 36698031 DOI: 10.1007/s11517-023-02784-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 01/15/2023] [Indexed: 01/27/2023]
Abstract
Respiration and cardiac activity are strictly interconnected with reciprocal influences. They act as weakly coupled oscillators showing varying degrees of phase synchronization and their interactions are affected by mechanical ventilation. The study aims at differentiating the impact of three ventilatory modes on the cardiorespiratory phase coupling in critically ill patients. The coupling between respiration and heartbeat was studied through cardiorespiratory phase synchronization analysis carried out via synchrogram during pressure control ventilation (PCV), pressure support ventilation (PSV), and neurally adjusted ventilatory assist (NAVA) in critically ill patients. Twenty patients were studied under all the three ventilatory modes. Cardiorespiratory phase synchronization changed significantly across ventilatory modes. The highest synchronization degree was found during PCV session, while the lowest one with NAVA. The percentage of all epochs featuring synchronization regardless of the phase locking ratio was higher with PCV (median: 33.9%, first-third quartile: 21.3-39.3) than PSV (median: 15.7%; first-third quartile: 10.9-27.8) and NAVA (median: 3.7%; first-third quartile: 3.3-19.2). PCV induces a significant amount of cardiorespiratory phase synchronization in critically ill mechanically ventilated patients. Synchronization induced by patient-driven ventilatory modes was weaker, reaching the minimum with NAVA. Findings can be explained as a result of the more regular and powerful solicitation of the cardiorespiratory system induced by PCV. The degree of phase synchronization between cardiac and respiratory activities in mechanically ventilated humans depends on the ventilatory mode.
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de Abreu RM, Cairo B, Porta A. On the significance of estimating cardiorespiratory coupling strength in sports medicine. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 2:1114733. [PMID: 36926078 PMCID: PMC10013023 DOI: 10.3389/fnetp.2022.1114733] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
The estimation of cardiorespiratory coupling (CRC) is attracting interest in sports physiology as an important tool to characterize cardiac neural regulation genuinely driven by respiration. When applied in sports medicine, cardiorespiratory coupling measurements can provide information on the effects of training, pre-competition stress, as well as cardiovascular adjustments during stressful stimuli. Furthermore, since the cardiorespiratory coupling is strongly affected by physical activity, the study of the cardiorespiratory coupling can guide the application of specific training methods to optimize the coupling between autonomic activity and heart with possible effects on performance. However, a consensus about the physiological mechanisms, as well as methodological gold standard methods to quantify the cardiorespiratory coupling, has not been reached yet, thus limiting its application in experimental settings. This review supports the relevance of assessing cardiorespiratory coupling in the sports medicine, examines the possible physiological mechanisms involved, and lists a series of methodological approaches. cardiorespiratory coupling strength seems to be increased in athletes when compared to sedentary subjects, in addition to being associated with positive physiological outcomes, such as a possible better interaction of neural subsystems to cope with stressful stimuli. Moreover, cardiorespiratory coupling seems to be influenced by specific training modalities, such as inspiratory muscle training. However, the impact of cardiorespiratory coupling on sports performance still needs to be better explored through ad hoc physical exercise tests and protocols. In addition, this review stresses that several bivariate and multivariate methods have been proposed to assess cardiorespiratory coupling, thus opening new possibilities in estimating cardiorespiratory interactions in athletes.
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Affiliation(s)
- Raphael Martins de Abreu
- Department of Physiotherapy, LUNEX University, International University of Health, Exercise & Sports S.A., Differdange, Luxembourg
- LUNEX ASBL Luxembourg Health & Sport Sciences Research Institute, Differdange, Luxembourg
| | - Beatrice Cairo
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Italy
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12
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Modified multiscale transfer entropy analysis of intra- and inter-couplings of cardio-respiratory systems during meditation. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.103983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Centracchio J, Esposito D, Gargiulo GD, Andreozzi E. Changes in Forcecardiography Heartbeat Morphology Induced by Cardio-Respiratory Interactions. SENSORS (BASEL, SWITZERLAND) 2022; 22:9339. [PMID: 36502041 PMCID: PMC9736082 DOI: 10.3390/s22239339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
The cardiac function is influenced by respiration. In particular, various parameters such as cardiac time intervals and the stroke volume are modulated by respiratory activity. It has long been recognized that cardio-respiratory interactions modify the morphology of cardio-mechanical signals, e.g., phonocardiogram, seismocardiogram (SCG), and ballistocardiogram. Forcecardiography (FCG) records the weak forces induced on the chest wall by the mechanical activity of the heart and lungs and relies on specific force sensors that are capable of monitoring respiration, infrasonic cardiac vibrations, and heart sounds, all simultaneously from a single site on the chest. This study addressed the changes in FCG heartbeat morphology caused by respiration. Two respiratory-modulated parameters were considered, namely the left ventricular ejection time (LVET) and a morphological similarity index (MSi) between heartbeats. The time trends of these parameters were extracted from FCG signals and further analyzed to evaluate their consistency within the respiratory cycle in order to assess their relationship with the breathing activity. The respiratory acts were localized in the time trends of the LVET and MSi and compared with a reference respiratory signal by computing the sensitivity and positive predictive value (PPV). In addition, the agreement between the inter-breath intervals estimated from the LVET and MSi and those estimated from the reference respiratory signal was assessed via linear regression and Bland-Altman analyses. The results of this study clearly showed a tight relationship between the respiratory activity and the considered respiratory-modulated parameters. Both the LVET and MSi exhibited cyclic time trends that remarkably matched the reference respiratory signal. In addition, they achieved a very high sensitivity and PPV (LVET: 94.7% and 95.7%, respectively; MSi: 99.3% and 95.3%, respectively). The linear regression analysis reported almost unit slopes for both the LVET (R2 = 0.86) and MSi (R2 = 0.97); the Bland-Altman analysis reported a non-significant bias for both the LVET and MSi as well as limits of agreement of ±1.68 s and ±0.771 s, respectively. In summary, the results obtained were substantially in line with previous findings on SCG signals, adding to the evidence that FCG and SCG signals share a similar information content.
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Affiliation(s)
- Jessica Centracchio
- Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Daniele Esposito
- Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Gaetano D. Gargiulo
- School of Engineering, Design and Built Environment, Western Sydney University, Penrith, NSW 2751, Australia
| | - Emilio Andreozzi
- Department of Electrical Engineering and Information Technologies, University of Naples Federico II, Via Claudio 21, 80125 Napoli, Italy
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14
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Clemson PT, Hoag JB, Cooke WH, Eckberg DL, Stefanovska A. Beyond the Baroreflex: A New Measure of Autonomic Regulation Based on the Time-Frequency Assessment of Variability, Phase Coherence and Couplings. FRONTIERS IN NETWORK PHYSIOLOGY 2022; 2:891604. [PMID: 36926062 PMCID: PMC10013010 DOI: 10.3389/fnetp.2022.891604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/03/2022] [Indexed: 11/13/2022]
Abstract
For decades the role of autonomic regulation and the baroreflex in the generation of the respiratory sinus arrhythmia (RSA) - modulation of heart rate by the frequency of breathing - has been under dispute. We hypothesized that by using autonomic blockers we can reveal which oscillations and their interactions are suppressed, elucidating their involvement in RSA as well as in cardiovascular regulation more generally. R-R intervals, end tidal CO2, finger arterial pressure, and muscle sympathetic nerve activity (MSNA) were measured simultaneously in 7 subjects during saline, atropine and propranolol infusion. The measurements were repeated during spontaneous and fixed-frequency breathing, and apnea. The power spectra, phase coherence and couplings were calculated to characterise the variability and interactions within the cardiovascular system. Atropine reduced R-R interval variability (p < 0.05) in all three breathing conditions, reduced MSNA power during apnea and removed much of the significant coherence and couplings. Propranolol had smaller effect on the power of oscillations and did not change the number of significant interactions. Most notably, atropine reduced R-R interval power in the 0.145-0.6 Hz interval during apnea, which supports the hypothesis that the RSA is modulated by a mechanism other than the baroreflex. Atropine also reduced or made negative the phase shift between the systolic and diastolic pressure, indicating the cessation of baroreflex-dependent blood pressure variability. This result suggests that coherent respiratory oscillations in the blood pressure can be used for the non-invasive assessment of autonomic regulation.
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Affiliation(s)
- Philip T. Clemson
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, United Kingdom
- Physics Department, Lancaster University, Lancaster, United Kingdom
| | - Jeffrey B. Hoag
- Jane and Leonard Korman Respiratory Institute, Thomas Jefferson University, Philadelphia, PA, United States
| | - William H. Cooke
- Kinesiology and Integrative Physiology Department, Michigan Technological University, Houghton, MI, United States
| | - Dwain L. Eckberg
- Departments of Medicine and Physiology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
- Department of Veterans Affairs Medical Center, Richmond, VA, United States
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15
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Sorelli M, Hutson TN, Iasemidis L, Bocchi L. Linear and Nonlinear Directed Connectivity Analysis of the Cardio-Respiratory System in Type 1 Diabetes. FRONTIERS IN NETWORK PHYSIOLOGY 2022; 2:840829. [PMID: 36926087 PMCID: PMC10013013 DOI: 10.3389/fnetp.2022.840829] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/14/2022] [Indexed: 12/31/2022]
Abstract
In this study, we explored the possibility of developing non-invasive biomarkers for patients with type 1 diabetes (T1D) by quantifying the directional couplings between the cardiac, vascular, and respiratory systems, treating them as interconnected nodes in a network configuration. Towards this goal, we employed a linear directional connectivity measure, the directed transfer function (DTF), estimated by a linear multivariate autoregressive modelling of ECG, respiratory and skin perfusion signals, and a nonlinear method, the dynamical Bayesian inference (DBI) analysis of bivariate phase interactions. The physiological data were recorded concurrently for a relatively short time period (5 min) from 10 healthy control subjects and 10 T1D patients. We found that, in both control and T1D subjects, breathing had greater influence on the heart and perfusion with respect to the opposite coupling direction and that, by both employed methods of analysis, the causal influence of breathing on the heart was significantly decreased (p < 0.05) in T1D patients compared to the control group. These preliminary results, although obtained from a limited number of subjects, provide a strong indication for the usefulness of a network-based multi-modal analysis for the development of biomarkers of T1D-related complications from short-duration data, as well as their potential in the exploration of the pathophysiological mechanisms that underlie this devastating and very widespread disease.
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Affiliation(s)
- Michele Sorelli
- European Laboratory for Non-Linear Spectroscopy, University of Florence, Florence, Italy
- Department of Physics and Astronomy, University of Florence, Florence, Italy
| | - T. Noah Hutson
- Department of Translational Neuroscience, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Leonidas Iasemidis
- Department of Translational Neuroscience, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Leonardo Bocchi
- European Laboratory for Non-Linear Spectroscopy, University of Florence, Florence, Italy
- Department of Information Engineering, University of Florence, Florence, Italy
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16
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Borovkova EI, Prokhorov MD, Kiselev AR, Hramkov AN, Mironov SA, Agaltsov MV, Ponomarenko VI, Karavaev AS, Drapkina OM, Penzel T. Directional couplings between the respiration and parasympathetic control of the heart rate during sleep and wakefulness in healthy subjects at different ages. FRONTIERS IN NETWORK PHYSIOLOGY 2022; 2:942700. [PMID: 36926072 PMCID: PMC10013057 DOI: 10.3389/fnetp.2022.942700] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022]
Abstract
Cardiorespiratory interactions are important, both for understanding the fundamental processes of functioning of the human body and for development of methods for diagnostics of various pathologies. The properties of cardiorespiratory interaction are determined by the processes of autonomic control of blood circulation, which are modulated by the higher nervous activity. We study the directional couplings between the respiration and the process of parasympathetic control of the heart rate in the awake state and different stages of sleep in 96 healthy subjects from different age groups. The detection of directional couplings is carried out using the method of phase dynamics modeling applied to experimental RR-intervals and the signal of respiration. We reveal the presence of bidirectional couplings between the studied processes in all age groups. Our results show that the coupling from respiration to the process of parasympathetic control of the heart rate is stronger than the coupling in the opposite direction. The difference in the strength of bidirectional couplings between the considered processes is most pronounced in deep sleep.
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Affiliation(s)
- Ekaterina I Borovkova
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Mikhail D Prokhorov
- Smart Sleep Laboratory, Saratov State University, Saratov, Russia.,Laboratory of Nonlinear Dynamics Modeling, Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Saratov, Russia
| | - Anton R Kiselev
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia.,Institute of Cardiological Research, Saratov State Medical University, Saratov, Russia
| | | | - Sergey A Mironov
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Mikhail V Agaltsov
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Vladimir I Ponomarenko
- Smart Sleep Laboratory, Saratov State University, Saratov, Russia.,Laboratory of Nonlinear Dynamics Modeling, Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Saratov, Russia
| | - Anatoly S Karavaev
- Smart Sleep Laboratory, Saratov State University, Saratov, Russia.,Laboratory of Nonlinear Dynamics Modeling, Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Saratov, Russia.,Institute of Cardiological Research, Saratov State Medical University, Saratov, Russia
| | - Oksana M Drapkina
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Thomas Penzel
- Smart Sleep Laboratory, Saratov State University, Saratov, Russia.,Interdisciplinary Sleep Medicine Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
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17
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Gruszecka A, Waskow M, Malkiewicz MA, Neary JP, Singh J, Teckchandani T, Kratzig GP, Wszedybyl-Winklewska M, Frydrychowski AF, Rumiński J, Głowacka N, Lass P, Winklewski PJ, Gruszecki M. Mild poikilocapnic hypoxia increases very low frequency haemoglobin oxygenation oscillations in prefrontal cortex. Biol Res 2021; 54:39. [PMID: 34906247 PMCID: PMC8669425 DOI: 10.1186/s40659-021-00362-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/30/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of the study was to investigate the effect of mild cerebral hypoxia on haemoglobin oxygenation (HbO2), cerebrospinal fluid dynamics and cardiovascular physiology. To achieve this goal, four signals were recorded simultaneously: blood pressure, heart rate / electrocardiogram, HbO2 from right hemisphere and changes of subarachnoid space (SAS) width from left hemisphere. Signals were registered from 30 healthy, young participants (2 females and 28 males, body mass index = 24.5 ± 2.3 kg/m2, age 30.8 ± 13.4 years). RESULTS We analysed the recorded signals using wavelet transform and phase coherence. We demonstrated for the first time that in healthy subjects exposed to mild poikilokapnic hypoxia there were increases in very low frequency HbO2 oscillations (< 0.052 Hz) in prefrontal cortex. Additionally, SAS fluctuation diminished in the whole frequency range which could be explained by brain oedema. CONCLUSIONS Consequently the study provides insight into mechanisms governing brain response to a mild hypoxic challenge. Our study supports the notion that HbO2 and SAS width monitoring might be beneficial for patients with acute lung disease.
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Affiliation(s)
- Agnieszka Gruszecka
- Department of Radiology Informatics and Statistics, Medical University of Gdansk, Tuwima Str. 15, 80-210, Gdansk, Poland
| | - Monika Waskow
- Institute of Health Sciences, Pomeranian University of Slupsk, Slupsk, Poland
| | - Marta A Malkiewicz
- Department of Human Physiology, Applied Cognitive Neuroscience Lab, Medical University of Gdansk, Gdansk, Poland.,Department of Psychiatry, Medical University of Gdansk, Gdansk, Poland
| | - J Patrick Neary
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | - Jyotpal Singh
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | - Taylor Teckchandani
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | | | | | | | - Jacek Rumiński
- Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | - Natalia Głowacka
- Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | - Piotr Lass
- Department of Nuclear Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Pawel J Winklewski
- Department of Human Physiology, Medical University of Gdansk, Gdansk, Poland
| | - Marcin Gruszecki
- Department of Radiology Informatics and Statistics, Medical University of Gdansk, Tuwima Str. 15, 80-210, Gdansk, Poland. .,Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland.
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18
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Zhu C, Fu Z, Liu L, Shi X, Li Y. Health risk assessment of PM 2.5 on walking trips. Sci Rep 2021; 11:19249. [PMID: 34584180 PMCID: PMC8478890 DOI: 10.1038/s41598-021-98844-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/13/2021] [Indexed: 12/31/2022] Open
Abstract
PM2.5 has an impact on residents' physical health during travelling, especially walking completely exposed to the environment. In order to obtain the specific impact of PM2.5 on walking, 368 healthy volunteers were selected and they were grouped according to gender and age. In the experiment, the heart rate change rate (HR%) is taken as test variable. According to receiver operating characteristic (ROC) curve, the travel is divided into two states: safety and risk. Based on this, a binary logit model considering Body Mass Index (BMI) is established to determine the contribution of PM2.5 concentration and body characteristics to travel risk. The experiment was conducted on Chang'an Middle Road in Xi'an City. The analysis results show that the threshold of HR% for safety and risk ranges from 31.1 to 40.1%, and that of PM2.5 concentration ranges from 81 to 168 μg/m3. The probability of risk rises 5.8% and 11.4%, respectively, for every unit increase in PM2.5 concentration and HR%. Under same conditions, the probability of risk for male is 76.8% of that for female. The probability of risk for youth is 67.5% of that for middle-aged people, and the probability of risk for people with BMI in healthy range is 72.1% of that for non-healthy range. The research evaluates risk characteristics of walking in particular polluted weather, which can improve residents' health level and provide suggestions for travel decision while walking.
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Affiliation(s)
- Caihua Zhu
- College of Transportation Engineering, Chang'an University, Middle section of south 2nd Ring Road, Xi'an, 710064, Shaanxi Province, China
| | - Zekun Fu
- College of Transportation Engineering, Chang'an University, Middle section of south 2nd Ring Road, Xi'an, 710064, Shaanxi Province, China
| | - Linjian Liu
- College of Transportation Engineering, Chang'an University, Middle section of south 2nd Ring Road, Xi'an, 710064, Shaanxi Province, China
| | - Xuan Shi
- College of Transportation Engineering, Chang'an University, Middle section of south 2nd Ring Road, Xi'an, 710064, Shaanxi Province, China
| | - Yan Li
- College of Transportation Engineering, Chang'an University, Middle section of south 2nd Ring Road, Xi'an, 710064, Shaanxi Province, China.
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19
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Mizeva I, Potapova E, Dremin V, Kozlov I, Dunaev A. Spatial heterogeneity of cutaneous blood flow respiratory-related oscillations quantified via laser speckle contrast imaging. PLoS One 2021; 16:e0252296. [PMID: 34043720 PMCID: PMC8158914 DOI: 10.1371/journal.pone.0252296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 01/21/2021] [Indexed: 11/18/2022] Open
Abstract
LSCI technique provides experimental data which can be considered in the context of spatial blood flow coherency. Analysis of vascular tone oscillations gives additional information to ensure a better understanding of the mechanisms affecting microvascular physiology. The oscillations with different frequencies are due to different physiological mechanisms. The reasons for the generation of peripheral blood flow oscillations in the 0.14-0.6 Hz frequency band are as follows: cardio-respiratory interactions, pressure variations in the venous part of the circulatory system, and the effect of the sympathetic nervous system on the vascular tone. Earlier, we described the spatial heterogeneity of around 0.3 Hz oscillations and this motivated us to continue the research to find the conditions for the occurrence of spatial phase synchronization. For this purpose, a number of physiological tests (controlled respiration, breath holder, and venous occlusion tests) which influence the blood flow oscillations of 0.14-0.6 Hz were considered, an appropriate measurement system and the required data processing algorithms were developed. At spontaneous respiration, the oscillations with frequencies around 0.3 Hz were stochastic, whereas all the performed tests induced an increase in spatial coherence. The protocols and methods proposed here can help to clarify whether the heterogeneity of respiratory-related blood flow oscillations exists on the skin surface.
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Affiliation(s)
- Irina Mizeva
- Institute of Continuous Media Mechanics UrB RAS, Perm, Russia
- Research & Development Center of Biomedical Photonics, Orel State University, Orel, Russia
- * E-mail:
| | - Elena Potapova
- Research & Development Center of Biomedical Photonics, Orel State University, Orel, Russia
| | - Viktor Dremin
- Research & Development Center of Biomedical Photonics, Orel State University, Orel, Russia
- College of Engineering and Physical Sciences, Aston University, Birmingham, United Kingdom
| | - Igor Kozlov
- Research & Development Center of Biomedical Photonics, Orel State University, Orel, Russia
| | - Andrey Dunaev
- Research & Development Center of Biomedical Photonics, Orel State University, Orel, Russia
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20
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Capdevila L, Parrado E, Ramos-Castro J, Zapata-Lamana R, Lalanza JF. Resonance frequency is not always stable over time and could be related to the inter-beat interval. Sci Rep 2021; 11:8400. [PMID: 33863966 PMCID: PMC8052415 DOI: 10.1038/s41598-021-87867-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 04/06/2021] [Indexed: 01/10/2023] Open
Abstract
Heart Rate Variability Biofeedback (HRVB) is based on breathing at an optimal rate (or resonance frequency, RF) corresponding to the respiratory sinus arrhythmia (RSA). Our aim is to check whether the RF is a stable factor and analyse the HRV parameters individually per each breathing rate, comparing it with free slow breathing. A sample of 21 participants were trained in a test–retest HRVB protocol. The results indicated that RF changed between Test and Retest sessions in 66.7% of participants. This instability could be related to the average of interbeat interval (IBI). HRV time domain parameters (SDNN and RMSSD) were significantly higher for RF than for other breathing rates, including 6 breath/min and free slow breathing. Free slow breathing showed a lower heart rate averages than RF and other slow breathing rates. Overall, our study suggests the relevance of assessing RF individually and before each HRVB session, because the maximum cardiovascular benefits in terms of increasing HRV were found only at RF. Thus, breathing at the individualized and momentary frequency of resonance increases cardiac variability.
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Affiliation(s)
- Lluis Capdevila
- Departament of Basic Psychology, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain. .,Sport Research Institute, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
| | - Eva Parrado
- Departament of Basic Psychology, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.,Sport Research Institute, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Juan Ramos-Castro
- Department of Electronic Engineering, Biomedical and Electronic Instrumentation Group, Universitat Politècnica de Catalunya, Barcelona, Spain
| | | | - Jaume F Lalanza
- Departament of Basic Psychology, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.,Department of Psychology, UiT The Arctic University of Norway, Tromsø, Norway
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21
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Be still my heart: Cardiac regulation as a mode of uncertainty reduction. Psychon Bull Rev 2021; 28:1211-1223. [PMID: 33755894 DOI: 10.3758/s13423-021-01888-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2021] [Indexed: 01/26/2023]
Abstract
Decreased heart rate (HR) and variability (HRV) are well-established correlates of attention; however, the functional significance of these dynamics remains unclear. Here, we investigate whether attention-related cardiac modulation is sensitive to different varieties of uncertainty. Thirty-nine adults performed a binocular rivalry-replay task in which changes in visual perception were driven either internally (in response to constant, conflicting stimuli; rivalry) or externally (in response to physically alternating stimuli; replay). Tonic HR and high-frequency HRV linearly decreased as participants progressed from resting-state baseline (minimal visual uncertainty) through replay (temporal uncertainty) to rivalry (temporal uncertainty and ambiguity). Time-resolved frequency estimates revealed that cardiac deceleration was sustained throughout the trial period and modulated by ambiguity, novelty, and switch rate. These findings suggest cardiac regulation during active attention may play an instrumental role in uncertainty reduction.
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22
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Coupling between Blood Pressure and Subarachnoid Space Width Oscillations during Slow Breathing. ENTROPY 2021; 23:e23010113. [PMID: 33467769 PMCID: PMC7830105 DOI: 10.3390/e23010113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/29/2020] [Accepted: 01/12/2021] [Indexed: 12/14/2022]
Abstract
The precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation and ventilation against inspiration resistance. The experiment was performed on a group of 20 healthy volunteers (12 females and 8 males; BMI =22.1±3.2 kg/m2; age 25.3±7.9 years). We analysed the recorded signals with a wavelet transform. For the first time, a method based on dynamical Bayesian inference was used to detect the effective phase connectivity and the underlying coupling functions between the SAS and BP signals. There are several new findings. Slow breathing with or without resistance increases the strength of the coupling between the respiratory and cardiac components of both measured signals. We also observed increases in the strength of the coupling between the respiratory component of the BP and the cardiac component of the SAS and vice versa. Slow breathing synchronises the SAS oscillations, between the brain hemispheres. It also diminishes the similarity of the coupling between all analysed pairs of oscillators, while inspiratory resistance partially reverses this phenomenon. BP–SAS and SAS–BP interactions may reflect changes in the overall biomechanical characteristics of the brain.
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23
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Huang YC, Lin TY, Wu HT, Chang PJ, Lo CY, Wang TY, Kuo CHS, Lin SM, Chung FT, Lin HC, Hsieh MH, Lo YL. Cardiorespiratory coupling is associated with exercise capacity in patients with chronic obstructive pulmonary disease. BMC Pulm Med 2021; 21:22. [PMID: 33435937 PMCID: PMC7802271 DOI: 10.1186/s12890-021-01400-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
Background The interaction between the pulmonary function and cardiovascular mechanics is a crucial issue, particularly when treating patients with chronic obstructive pulmonary disease (COPD). Synchrogram index is a new parameter that can quantify this interaction and has the potential to apply in COPD patients. Our objective in this study was to characterize cardiorespiratory interactions in terms of cardiorespiratory coupling (CRC) using the synchrogram index of the heart rate and respiratory flow signals in patients with chronic obstructive pulmonary disease. Methods This is a cross-sectional and preliminary data from a prospective study, which examines 55 COPD patients. K-means clustering analysis was applied to cluster COPD patients based on the synchrogram index. Linear regression and multivariable regression analysis were used to determine the correlation between the synchrogram index and the exercise capacity assessed by a six-minute walking test (6MWT). Results The 55 COPD patients were separated into a synchronized group (median 0.89 (0.64–0.97), n = 43) and a desynchronized group (median 0.23 (0.02–0.51), n = 12) based on K-means clustering analysis. Synchrogram index was correlated significantly with six minutes walking distance (r = 0.42, p = 0.001) and distance saturation product (r = 0.41, p = 0.001) assessed by 6MWT, and still was an independent variable by multivariable regression analysis. Conclusion This is the first result studying the heart–lung interaction in terms of cardiorespiratory coupling in COPD patients by the synchrogram index, and COPD patients are clustered into synchronized and desynchronized groups. Cardiorespiratory coupling is associated with exercise capacity in patients with COPD.
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Affiliation(s)
- Yu-Chen Huang
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ting-Yu Lin
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hau-Tieng Wu
- Department of Mathematics, Duke University, Durham, NC, USA.,Department of Statistical Sciences, Duke University, Durham, NC, USA
| | - Po-Jui Chang
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chun-Yu Lo
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tsai-Yu Wang
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Hsi Scott Kuo
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shu-Min Lin
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Fu-Tsai Chung
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Horng-Chyuan Lin
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Meng-Heng Hsieh
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Lun Lo
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, 199 Tun-Hwa N. Rd., Taipei, Taiwan. .,College of Medicine, Chang Gung University, Taoyuan, Taiwan.
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24
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Lukarski D, Ginovska M, Spasevska H, Stankovski T. Time Window Determination for Inference of Time-Varying Dynamics: Application to Cardiorespiratory Interaction. Front Physiol 2020; 11:341. [PMID: 32411009 PMCID: PMC7198895 DOI: 10.3389/fphys.2020.00341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 03/24/2020] [Indexed: 11/13/2022] Open
Abstract
Interacting dynamical systems abound in nature, with examples ranging from biology and population dynamics, through physics and chemistry, to communications and climate. Often their states, parameters and functions are time-varying, because such systems interact with other systems and the environment, exchanging information and matter. A common problem when analysing time-series data from dynamical systems is how to determine the length of the time window for the analysis. When one needs to follow the time-variability of the dynamics, or the dynamical parameters and functions, the time window needs to be resolved first. We tackled this problem by introducing a method for adaptive determination of the time window for interacting oscillators, as modeled and scaled for the cardiorespiratory interaction. By investigating a system of coupled phase oscillators and utilizing the Dynamical Bayesian Inference method, we propose a procedure to determine the time window and the propagation parameter of the covariance matrix. The optimal values are determined so that the inferred parameters follow the dynamics of the actual ones and at the same time the error of the inference represented by the covariance matrix is minimal. The effectiveness of the methodology is presented on a system of coupled limit-cycle oscillators and on the cardiorespiratory interaction. Three cases of cardiorespiratory interaction were considered-measurement with spontaneous free breathing, one with periodic sine breathing and one with a-periodic time-varying breathing. The results showed that the cardiorespiratory coupling strength and similarity of form of coupling functions have greater values for slower breathing, and this variability follows continuously the change of the breathing frequency. The method can be applied effectively to other time-varying oscillatory interactions and carries important implications for analysis of general dynamical systems.
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Affiliation(s)
- Dushko Lukarski
- Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, Macedonia
- University Clinic for Radiotherapy and Oncology, Skopje, Macedonia
| | - Margarita Ginovska
- Faculty of Electrical Engineering and Information Technologies, Ss. Cyril and Methodius University, Skopje, Macedonia
| | - Hristina Spasevska
- Faculty of Electrical Engineering and Information Technologies, Ss. Cyril and Methodius University, Skopje, Macedonia
| | - Tomislav Stankovski
- Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, Macedonia
- Department of Physics, Lancaster University, Lancaster, United Kingdom
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Lin C, Lin PF, Wang CH, Juan CH, Tran TT, Pham VT, Nien CT, Lin YJ, Wang CY, Yeh CH, Lo MT. Probing age-related changes in cardio-respiratory dynamics by multimodal coupling assessment. CHAOS (WOODBURY, N.Y.) 2020; 30:033118. [PMID: 32237792 DOI: 10.1063/1.5134868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/13/2020] [Indexed: 06/11/2023]
Abstract
Quantifying respiratory sinus arrhythmia (RSA) can provide an index of parasympathetic function. Fourier spectral analysis, the most widely used approach, estimates the power of the heart rate variability in the frequency band of breathing. However, it neglects the time-varying characteristics of the transitions as well as the nonlinear properties of the cardio-respiratory coupling. Here, we propose a novel approach based on Hilbert-Huang transform, called the multimodal coupling analysis (MMCA) method, to assess cardio-respiratory dynamics by examining the instantaneous nonlinear phase interactions between two interconnected signals (i.e., heart rate and respiration) and compare with the counterparts derived from the wavelet-based method. We used an online database. The corresponding RSA components of the 90-min ECG and respiratory signals of 20 young and 20 elderly healthy subjects were extracted and quantified. A cycle-based analysis and a synchro-squeezed wavelet transform were also introduced to assess the amplitude or phase changes of each respiratory cycle. Our results demonstrated that the diminished mean and standard deviation of the derived dynamical RSA activities can better discriminate between elderly and young subjects. Moreover, the degree of nonlinearity of the cycle-by-cycle RSA waveform derived from the differences between the instantaneous frequency and the mean frequency of each respiratory cycle was significantly decreased in the elderly subjects by the MMCA method. The MMCA method in combination with the cycle-based analysis can potentially be a useful tool to depict the aging changes of the parasympathetic function as well as the waveform nonlinearity of RSA compared to the Fourier-based high-frequency power and the wavelet-based method.
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Affiliation(s)
- Chen Lin
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Pei-Feng Lin
- Department of Geriatrics, Tainan Hospital, Ministry of Health and Welfare, Tainan 700, Taiwan
| | - Chen-Hsu Wang
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Chung-Hau Juan
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Thi-Thao Tran
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Van-Truong Pham
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Chun-Tung Nien
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Yenn-Jiang Lin
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Cheng-Yen Wang
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
| | - Chien-Hung Yeh
- School of information and Electronics Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Men-Tzung Lo
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan 320, Taiwan
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de Abreu RM, Catai AM, Cairo B, Rehder-Santos P, da Silva CD, Signini ÉDF, Sakaguchi CA, Porta A. A Transfer Entropy Approach for the Assessment of the Impact of Inspiratory Muscle Training on the Cardiorespiratory Coupling of Amateur Cyclists. Front Physiol 2020; 11:134. [PMID: 32158402 PMCID: PMC7052290 DOI: 10.3389/fphys.2020.00134] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 02/07/2020] [Indexed: 12/23/2022] Open
Abstract
The strength of cardiorespiratory interactions diminishes with age. Physical exercise can reduce the rate of this trend. Inspiratory muscle training (IMT) is a technique capable of improving cardiorespiratory interactions. This study evaluates the effect of IMT on cardiorespiratory coupling in amateur cyclists. Thirty male young healthy cyclists underwent a sham IMT of very low intensity (SHAM, n = 9), an IMT of moderate intensity at 60% of the maximal inspiratory pressure (MIP60, n = 10) and an IMT of high intensity at the critical inspiratory pressure (CIP, n = 11). Electrocardiogram, non-invasive arterial pressure, and thoracic respiratory movement (RM) were recorded before (PRE) and after (POST) training at rest in supine position (REST) and during active standing (STAND). The beat-to-beat series of heart period (HP) and systolic arterial pressure (SAP) were analyzed with the RM signal via a traditional non-causal approach, such as squared coherence function, and via a causal model-based transfer entropy (TE) approach. Cardiorespiratory coupling was quantified via the HP-RM squared coherence at the respiratory rate (K 2 HP-R M), the unconditioned TE from RM to HP (TER M → HP) and the TE from RM to HP conditioned on SAP (TER M → HP| SAP). In PRE condition we found that STAND led to a decrease of TER M → HP| SAP. After SHAM and CIP training this tendency was confirmed, while MIP60 inverted it by empowering cardiorespiratory coupling. This behavior was observed in presence of unvaried SAP mean and with usual responses of the baroreflex control and HP mean to STAND. TER M → HP and K 2 HP- RM were not able to detect the post-training increase of cardiorespiratory coupling strength during STAND, thus suggesting that conditioning out SAP is important for the assessment of cardiorespiratory interactions. Since the usual response of HP mean, SAP mean and baroreflex sensitivity to postural stressor were observed after MIP60 training, we conclude that the post-training increase of cardiorespiratory coupling during STAND in MIP60 group might be the genuine effect of some rearrangements at the level of central respiratory network and its interactions with sympathetic drive and vagal activity.
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Affiliation(s)
| | - Aparecida Maria Catai
- Department of Physical Therapy, Federal University of São Carlos, São Carlos, Brazil
| | - Beatrice Cairo
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | | | | | | | | | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
- Department of Cardiothoracic – Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
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Rosenblum M, Pikovsky A. Nonlinear phase coupling functions: a numerical study. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20190093. [PMID: 31656143 PMCID: PMC6833997 DOI: 10.1098/rsta.2019.0093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Phase reduction is a general tool widely used to describe forced and interacting self-sustained oscillators. Here, we explore the phase coupling functions beyond the usual first-order approximation in the strength of the force. Taking the periodically forced Stuart-Landau oscillator as the paradigmatic model, we determine and numerically analyse the coupling functions up to the fourth order in the force strength. We show that the found nonlinear phase coupling functions can be used for predicting synchronization regions of the forced oscillator. This article is part of the theme issue 'Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences'.
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Affiliation(s)
- Michael Rosenblum
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24/25, 14476 Potsdam-Golm, Germany
- Control Theory Department, Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University Nizhny Novgorod, Nizhny Novgorod, Russia
- e-mail:
| | - Arkady Pikovsky
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24/25, 14476 Potsdam-Golm, Germany
- Control Theory Department, Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University Nizhny Novgorod, Nizhny Novgorod, Russia
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Stankovski T, Pereira T, McClintock PVE, Stefanovska A. Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20190039. [PMID: 31656134 PMCID: PMC6834002 DOI: 10.1098/rsta.2019.0039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
Dynamical systems are widespread, with examples in physics, chemistry, biology, population dynamics, communications, climatology and social science. They are rarely isolated but generally interact with each other. These interactions can be characterized by coupling functions-which contain detailed information about the functional mechanisms underlying the interactions and prescribe the physical rule specifying how each interaction occurs. Coupling functions can be used, not only to understand, but also to control and predict the outcome of the interactions. This theme issue assembles ground-breaking work on coupling functions by leading scientists. After overviewing the field and describing recent advances in the theory, it discusses novel methods for the detection and reconstruction of coupling functions from measured data. It then presents applications in chemistry, neuroscience, cardio-respiratory physiology, climate, electrical engineering and social science. Taken together, the collection summarizes earlier work on coupling functions, reviews recent developments, presents the state of the art, and looks forward to guide the future evolution of the field. This article is part of the theme issue 'Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences'.
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Affiliation(s)
- Tomislav Stankovski
- Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
- Faculty of Medicine, Ss Cyril and Methodius University, Skopje 1000, Macedonia
| | - Tiago Pereira
- Department of Mathematics, Imperial College London, London SW7 2AZ, UK
- Institute of Mathematical and Computer Sciences, University of Sao Paulo, Sao Carlos 13566-590, Brazil
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Rosenblum M, Frühwirth M, Moser M, Pikovsky A. Dynamical disentanglement in an analysis of oscillatory systems: an application to respiratory sinus arrhythmia. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20190045. [PMID: 31656138 PMCID: PMC6834001 DOI: 10.1098/rsta.2019.0045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/28/2019] [Indexed: 05/17/2023]
Abstract
We develop a technique for the multivariate data analysis of perturbed self-sustained oscillators. The approach is based on the reconstruction of the phase dynamics model from observations and on a subsequent exploration of this model. For the system, driven by several inputs, we suggest a dynamical disentanglement procedure, allowing us to reconstruct the variability of the system's output that is due to a particular observed input, or, alternatively, to reconstruct the variability which is caused by all the inputs except for the observed one. We focus on the application of the method to the vagal component of the heart rate variability caused by a respiratory influence. We develop an algorithm that extracts purely respiratory-related variability, using a respiratory trace and times of R-peaks in the electrocardiogram. The algorithm can be applied to other systems where the observed bivariate data can be represented as a point process and a slow continuous signal, e.g. for the analysis of neuronal spiking. This article is part of the theme issue 'Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences'.
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Affiliation(s)
- M. Rosenblum
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam-Golm, Germany
- Control Theory Department, Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University Nizhny Novgorod, Nizhny Novgorod, Russia
| | - M. Frühwirth
- Human Research Institute of Health Technology and Prevention Research, Franz Pichler Street 30, 8160 Weiz, Austria
| | - M. Moser
- Human Research Institute of Health Technology and Prevention Research, Franz Pichler Street 30, 8160 Weiz, Austria
- Physiology Division, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, Neue Stiftingtalstr. 6/D05, 8010 Graz, Austria
| | - A. Pikovsky
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam-Golm, Germany
- Control Theory Department, Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University Nizhny Novgorod, Nizhny Novgorod, Russia
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Hagos Z, Stankovski T, Newman J, Pereira T, McClintock PVE, Stefanovska A. Synchronization transitions caused by time-varying coupling functions. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20190275. [PMID: 31656137 PMCID: PMC6834000 DOI: 10.1098/rsta.2019.0275] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
Interacting dynamical systems are widespread in nature. The influence that one such system exerts on another is described by a coupling function; and the coupling functions extracted from the time-series of interacting dynamical systems are often found to be time-varying. Although much effort has been devoted to the analysis of coupling functions, the influence of time-variability on the associated dynamics remains largely unexplored. Motivated especially by coupling functions in biology, including the cardiorespiratory and neural delta-alpha coupling functions, this paper offers a contribution to the understanding of effects due to time-varying interactions. Through both numerics and mathematically rigorous theoretical consideration, we show that for time-variable coupling functions with time-independent net coupling strength, transitions into and out of phase- synchronization can occur, even though the frozen coupling functions determine phase-synchronization solely by virtue of their net coupling strength. Thus the information about interactions provided by the shape of coupling functions plays a greater role in determining behaviour when these coupling functions are time-variable. This article is part of the theme issue 'Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences'.
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Affiliation(s)
- Zeray Hagos
- Institute of Mathematical and Computer Sciences, University of São Paulo, São Carlos 13566-590, Brazil
- Department of Mathematics, Mekelle University, Mekelle, Ethiopia
| | - Tomislav Stankovski
- Faculty of Medicine, Ss Cyril and Methodius University, 50 Divizija 6, Skopje, North Macedonia
- Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
| | - Julian Newman
- Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
| | - Tiago Pereira
- Institute of Mathematical and Computer Sciences, University of São Paulo, São Carlos 13566-590, Brazil
- Department of Mathematics, Imperial College London, London SW7 2AZ, UK
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Abdulhameed YA, Lancaster G, McClintock PVE, Stefanovska A. On the suitability of laser-Doppler flowmetry for capturing microvascular blood flow dynamics from darkly pigmented skin. Physiol Meas 2019; 40:074005. [DOI: 10.1088/1361-6579/ab2651] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Assessment of Interaction Between Cardio-Respiratory Signals Using Directed Coherence on Healthy Subjects During Postural Change. Ing Rech Biomed 2019. [DOI: 10.1016/j.irbm.2019.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Nuckowska MK, Gruszecki M, Kot J, Wolf J, Guminski W, Frydrychowski AF, Wtorek J, Narkiewicz K, Winklewski PJ. Impact of slow breathing on the blood pressure and subarachnoid space width oscillations in humans. Sci Rep 2019; 9:6232. [PMID: 30996273 PMCID: PMC6470142 DOI: 10.1038/s41598-019-42552-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/29/2019] [Indexed: 02/08/2023] Open
Abstract
The aim of the study was to assess cardiac and respiratory blood pressure (BP) and subarachnoid space (SAS) width oscillations during the resting state for slow and fast breathing and breathing against inspiratory resistance. Experiments were performed on a group of 20 healthy volunteers (8 males and 12 females; age 25.3 ± 7.9 years; BMI = 22.1 ± 3.2 kg/m2). BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography. SAS signals were recorded using an SAS monitor. Oxyhaemoglobin saturation (SaO2) and end-tidal CO2 (EtCO2) were measured using a medical monitoring system. Procedure 1 consisted of breathing spontaneously and at controlled rates of 6 breaths/minute and 6 breaths/minute with inspiratory resistance for 10 minutes. Procedure 2 consisted of breathing spontaneously and at controlled rates of 6, 12 and 18 breaths/minute for 5 minutes. Wavelet analysis with the Morlet mother wavelet was applied for delineation of BP and SAS signals cardiac and respiratory components. Slow breathing diminishes amplitude of cardiac BP and SAS oscillations. The overall increase in BP and SAS oscillations during slow breathing is driven by the respiratory component. Drop in cardiac component of BP amplitude evoked by slow-breathing may be perceived as a cardiovascular protective mechanism to avoid target organ damage. Further studies are warranted to assess long-term effects of slow breathing.
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Affiliation(s)
- Magdalena K Nuckowska
- Department of Human Physiology, Faculty of Health Sciences, Medical University of Gdansk, Gdansk, Poland
| | - Marcin Gruszecki
- Department of Radiology Informatics and Statistics, Faculty of Health Sciences, Medical University of Gdansk, Gdansk, Poland
| | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine, Faculty of Health Sciences, Medical University of Gdansk, Gdynia, Poland
| | - Jacek Wolf
- Department of Hypertension and Diabetology, Faculty of Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Wojciech Guminski
- Department of Computer Communications, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | | | - Jerzy Wtorek
- Department of Biomedical Engineering, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | - Krzysztof Narkiewicz
- Department of Hypertension and Diabetology, Faculty of Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Pawel J Winklewski
- Department of Human Physiology, Faculty of Health Sciences, Medical University of Gdansk, Gdansk, Poland.
- Department of Clinical Anatomy and Physiology, Faculty of Health Sciences, Pomeranian University of Slupsk, Slupsk, Poland.
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Lucas M, Fanelli D, Stefanovska A. Nonautonomous driving induces stability in network of identical oscillators. Phys Rev E 2019; 99:012309. [PMID: 30780263 DOI: 10.1103/physreve.99.012309] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Indexed: 04/17/2023]
Abstract
Nonautonomous driving of an oscillator has been shown to enlarge the Arnold tongue in parameter space, but little is known about the analogous effect for a network of oscillators. To test the hypothesis that deterministic nonautonomous perturbation is a good candidate for stabilizing complex dynamics, we consider a network of identical phase oscillators driven by an oscillator with a slowly time-varying frequency. We investigate both the short- and long-term stability of the synchronous solutions of this nonautonomous system. For attractive couplings we show that the region of stability grows as the amplitude of the frequency modulation is increased, through the birth of an intermittent synchronization regime. For repulsive couplings, we propose a control strategy to stabilize the dynamics by altering very slightly the network topology. We also show how, without changing the topology, time-variability in the driving frequency can itself stabilize the dynamics. As a byproduct of the analysis, we observe chimeralike states. We conclude that time-variability-induced stability phenomena are also present in networks, reinforcing the idea that this is a quite realistic scenario for living systems to use in maintaining their functioning in the face of ongoing perturbations.
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Affiliation(s)
- Maxime Lucas
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
- Dipartimento di Fisica e Astronomia, Università di Firenze, INFN and CSDC, Via Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Duccio Fanelli
- Dipartimento di Fisica e Astronomia, Università di Firenze, INFN and CSDC, Via Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Aneta Stefanovska
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
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Paced Breathing Increases the Redundancy of Cardiorespiratory Control in Healthy Individuals and Chronic Heart Failure Patients. ENTROPY 2018; 20:e20120949. [PMID: 33266673 PMCID: PMC7512533 DOI: 10.3390/e20120949] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/04/2018] [Accepted: 12/06/2018] [Indexed: 11/17/2022]
Abstract
Synergy and redundancy are concepts that suggest, respectively, adaptability and fault tolerance of systems with complex behavior. This study computes redundancy/synergy in bivariate systems formed by a target X and a driver Y according to the predictive information decomposition approach and partial information decomposition framework based on the minimal mutual information principle. The two approaches assess the redundancy/synergy of past of X and Y in reducing the uncertainty of the current state of X. The methods were applied to evaluate the interactions between heart and respiration in healthy young subjects (n = 19) during controlled breathing at 10, 15 and 20 breaths/minute and in two groups of chronic heart failure patients during paced respiration at 6 (n = 9) and 15 (n = 20) breaths/minutes from spontaneous beat-to-beat fluctuations of heart period and respiratory signal. Both methods suggested that slowing respiratory rate below the spontaneous frequency increases redundancy of cardiorespiratory control in both healthy and pathological groups, thus possibly improving fault tolerance of the cardiorespiratory control. The two methods provide markers complementary to respiratory sinus arrhythmia and the strength of the linear coupling between heart period variability and respiration in describing the physiology of the cardiorespiratory reflex suitable to be exploited in various pathophysiological settings.
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Topçu Ç, Frühwirth M, Moser M, Rosenblum M, Pikovsky A. Disentangling respiratory sinus arrhythmia in heart rate variability records. Physiol Meas 2018; 39:054002. [DOI: 10.1088/1361-6579/aabea4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Blomqvist BRH, Mann RP, Sumpter DJT. Using Bayesian dynamical systems, model averaging and neural networks to determine interactions between socio-economic indicators. PLoS One 2018; 13:e0196355. [PMID: 29742126 PMCID: PMC5942783 DOI: 10.1371/journal.pone.0196355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/11/2018] [Indexed: 12/12/2022] Open
Abstract
Social and economic systems produce complex and nonlinear relationships in the indicator variables that describe them. We present a Bayesian methodology to analyze the dynamical relationships between indicator variables by identifying the nonlinear functions that best describe their interactions. We search for the 'best' explicit functions by fitting data using Bayesian linear regression on a vast number of models and then comparing their Bayes factors. The model with the highest Bayes factor, having the best trade-off between explanatory power and interpretability, is chosen as the 'best' model. To be able to compare a vast number of models, we use conjugate priors, resulting in fast computation times. We check the robustness of our approach by comparison with more prediction oriented approaches such as model averaging and neural networks. Our modelling approach is illustrated using the classical example of how democracy and economic growth relate to each other. We find that the best dynamical model for democracy suggests that long term democratic increase is only possible if the economic situation gets better. No robust model explaining economic development using these two variables was found.
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Affiliation(s)
| | - Richard P. Mann
- University of Leeds, School of Mathematics, Leeds, United Kingdom
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Kontaxis S, Lazaro J, Gil E, Laguna P, Bailon R. Assessment of Quadratic Nonlinear Cardiorespiratory Couplings During Tilt-Table Test by Means of Real Wavelet Biphase. IEEE Trans Biomed Eng 2018; 66:187-198. [PMID: 29993448 DOI: 10.1109/tbme.2018.2821182] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE In this paper, a method for assessment of quadratic phase coupling (QPC) between respiration and heart rate variability (HRV) is presented. METHODS First, a method for QPC detection is proposed named real wavelet biphase (RWB). Then, a method for QPC quantification is proposed based on the normalized wavelet biamplitude (NWB). A simulation study has been conducted to test the reliability of RWB to identify QPC, even in the presence of constant delays between interacting oscillations, and to discriminate it from quadratic phase uncoupling. Significant QPC was assessed based on surrogate data analysis. Then, quadratic cardiorespiratory couplings were studied during a tilt-table test protocol of 17 young healthy subjects. RESULTS Simulation study showed that RWB is able to detect even weak QPC with delays in the range of [Formula: see text] s, which are usual in the autonomic nervous system (ANS) control of heart rate. Results from the database revealed a significant reduction ([Formula: see text]) of NWB between respiration and both low and high frequencies of HRV in head-up tilt position compared to early supine. CONCLUSION The proposed technique detects and quantifies robustly QPC and is able to track the coupling between respiration and various HRV components during ANS changes. SIGNIFICANCE The proposed method can help to assess alternations of nonlinear cardiorespiratory interactions related to ANS dysfunction and physiological regulation of HRV in cardiovascular diseases.
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Skytioti M, Søvik S, Elstad M. Dynamic cerebral autoregulation is preserved during isometric handgrip and head-down tilt in healthy volunteers. Physiol Rep 2018; 6:e13656. [PMID: 29595918 PMCID: PMC5875546 DOI: 10.14814/phy2.13656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 02/20/2018] [Accepted: 02/26/2018] [Indexed: 12/29/2022] Open
Abstract
In healthy humans, cerebral blood flow (CBF) is autoregulated against changes in arterial blood pressure. Spontaneous fluctuations in mean arterial pressure (MAP) and CBF can be used to assess cerebral autoregulation. We hypothesized that dynamic cerebral autoregulation is affected by changes in autonomic activity, MAP, and cardiac output (CO) induced by handgrip (HG), head‐down tilt (HDT), and their combination. In thirteen healthy volunteers, we recorded blood velocity by ultrasound in the internal carotid artery (ICA), HR, MAP and CO‐estimates from continuous finger blood pressure, and end‐tidal CO2. Instantaneous ICA beat volume (ICABV, mL) and ICA blood flow (ICABF, mL/min) were calculated. Wavelet synchronization index γ (0–1) was calculated for the pairs: MAP–ICABF, CO–ICABF and HR–ICABV in the low (0.05–0.15 Hz; LF) and high (0.15–0.4 Hz; HF) frequency bands. ICABF did not change between experimental states. MAP and CO were increased during HG (+16% and +15%, respectively, P < 0.001) and during HDT + HG (+12% and +23%, respectively, P < 0.001). In the LF interval, median γ for the MAP–ICABF pair (baseline: 0.23 [0.12–0.28]) and the CO–ICABF pair (baseline: 0.22 [0.15–0.28]) did not change with HG, HDT, or their combination. High γ was observed for the HR–ICABV pair at the respiratory frequency, the oscillations in these variables being in inverse phase. The unaltered ICABF and the low synchronization between MAP and ICABF in the LF interval suggest intact dynamic cerebral autoregulation during HG, HDT, and their combination.
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Affiliation(s)
- Maria Skytioti
- Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Signe Søvik
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Anaesthesia and Intensive Care, Akershus University Hospital, Lørenskog, Norway
| | - Maja Elstad
- Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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41
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Gruszecki M, Lancaster G, Stefanovska A, Neary JP, Dech RT, Guminski W, Frydrychowski AF, Kot J, Winklewski PJ. Human subarachnoid space width oscillations in the resting state. Sci Rep 2018; 8:3057. [PMID: 29449606 PMCID: PMC5814422 DOI: 10.1038/s41598-018-21038-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/29/2018] [Indexed: 11/17/2022] Open
Abstract
Abnormal cerebrospinal fluid (CSF) pulsatility has been implicated in patients suffering from various diseases, including multiple sclerosis and hypertension. CSF pulsatility results in subarachnoid space (SAS) width changes, which can be measured with near-infrared transillumination backscattering sounding (NIR-T/BSS). The aim of this study was to combine NIR-T/BSS and wavelet analysis methods to characterise the dynamics of the SAS width within a wide range of frequencies from 0.005 to 2 Hz, with low frequencies studied in detail for the first time. From recordings in the resting state, we also demonstrate the relationships between SAS width in both hemispheres of the brain, and investigate how the SAS width dynamics is related to the blood pressure (BP). These investigations also revealed influences of age and SAS correlation on the dynamics of SAS width and its similarity with the BP. Combination of NIR-T/BSS and time-frequency analysis may open up new frontiers in the understanding and diagnosis of various neurodegenerative and ageing related diseases to improve diagnostic procedures and patient prognosis.
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Affiliation(s)
- Marcin Gruszecki
- Department of Radiology Informatics and Statistics, Medical University of Gdansk, Gdansk, Poland.
| | | | | | - J Patrick Neary
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | - Ryan T Dech
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, Canada
| | - Wojciech Guminski
- Department of Computer Communications, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Gdansk, Poland
| | | | - Jacek Kot
- National Centre for Hyperbaric Medicine, Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Gdynia, Poland
| | - Pawel J Winklewski
- Department of Human Physiology, Medical University of Gdansk, Gdansk, Poland.,Department of Clinical Anatomy and Physiology, Pomeranian University of Slupsk, Slupsk, Poland
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42
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Ticcinelli V, Stankovski T, Iatsenko D, Bernjak A, Bradbury AE, Gallagher AR, Clarkson PBM, McClintock PVE, Stefanovska A. Coherence and Coupling Functions Reveal Microvascular Impairment in Treated Hypertension. Front Physiol 2017; 8:749. [PMID: 29081750 PMCID: PMC5645539 DOI: 10.3389/fphys.2017.00749] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 09/14/2017] [Indexed: 01/02/2023] Open
Abstract
The complex interactions that give rise to heart rate variability (HRV) involve coupled physiological oscillators operating over a wide range of different frequencies and length-scales. Based on the premise that interactions are key to the functioning of complex systems, the time-dependent deterministic coupling parameters underlying cardiac, respiratory and vascular regulation have been investigated at both the central and microvascular levels. Hypertension was considered as an example of a globally altered state of the complex dynamics of the cardiovascular system. Its effects were established through analysis of simultaneous recordings of the electrocardiogram (ECG), respiratory effort, and microvascular blood flow [by laser Doppler flowmetry (LDF)]. The signals were analyzed by methods developed to capture time-dependent dynamics, including the wavelet transform, wavelet-based phase coherence, non-linear mode decomposition, and dynamical Bayesian inference, all of which can encompass the inherent frequency and coupling variability of living systems. Phases of oscillatory modes corresponding to the cardiac (around 1.0 Hz), respiratory (around 0.25 Hz), and vascular myogenic activities (around 0.1 Hz) were extracted and combined into two coupled networks describing the central and peripheral systems, respectively. The corresponding spectral powers and coupling functions were computed. The same measurements and analyses were performed for three groups of subjects: healthy young (Y group, 24.4 ± 3.4 y), healthy aged (A group, 71.1 ± 6.6 y), and aged treated hypertensive patients (ATH group, 70.3 ± 6.7 y). It was established that the degree of coherence between low-frequency oscillations near 0.1 Hz in blood flow and in HRV time series differs markedly between the groups, declining with age and nearly disappearing in treated hypertension. Comparing the two healthy groups it was found that the couplings to the cardiac rhythm from both respiration and vascular myogenic activity decrease significantly in aging. Comparing the data from A and ATH groups it was found that the coupling from the vascular myogenic activity is significantly weaker in treated hypertension subjects, implying that the mechanisms of microcirculation are not completely restored by current anti-hypertension medications.
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Affiliation(s)
| | - Tomislav Stankovski
- Physics Department, Lancaster University, Lancaster, United Kingdom
- Faculty of Medicine, Saints Cyril and Methodius University of Skopje, Skopje, Macedonia
| | - Dmytro Iatsenko
- Physics Department, Lancaster University, Lancaster, United Kingdom
- Deutsche Bank AG, London, United Kingdom
| | - Alan Bernjak
- Physics Department, Lancaster University, Lancaster, United Kingdom
- Department of Oncology & Metabolism, University of Sheffield, Sheffield, United Kingdom
| | - Adam E. Bradbury
- Physics Department, Lancaster University, Lancaster, United Kingdom
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43
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Porta A, Bari V, De Maria B, Baumert M. A network physiology approach to the assessment of the link between sinoatrial and ventricular cardiac controls. Physiol Meas 2017; 38:1472-1489. [PMID: 28430108 DOI: 10.1088/1361-6579/aa6e95] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE A network physiology approach to evaluate the strength of the directed interactions among cardiac controls at sinoatrial and ventricular levels and respiration (R) is proposed. APPROACH The network is composed of three nodes (i.e. sinoatrial and ventricular cardiac controls and R) and their activity is exemplified by the variability of heart period (HP), the variability of the duration of the electrical activity of the heart approximated as the temporal distance between Q-wave onset and T-wave end or apex (i.e. QTe or QTa) and thoracic movements respectively. Model-based transfer entropy provided the estimate of the strength of the causal link from the source to the destination conditioned on the remaining node activity. The interactions were monitored in 15 healthy subjects aged from 24 to 54 years (9 males). Increasing levels of sympathetic activity were induced by graded head-up tilt with table inclination of 0, 15, 30, 45, 60, 75°. MAIN RESULTS We found that: (i) the strength of the causal link from HP to QTe gradually decreases with tilt table angle, while that in the reverse direction is weak, even though significant, and constant; (ii) the action of R on HP is stronger than that from R to QTe; (iii) the strength of the relation from R to HP is weakly related to tilt table inclination, while that from R to QTe does not depend on it; (iv) while QTe cannot affect R, a weak causal dependence of R on HP is detected; (v) the network computed over QTa is qualitatively similar to that over QTe, even though the strength of the causal relations might be different. SIGNIFICANCE The proposed network physiology approach provides a comprehensive picture of the directed links among relevant cardiac regulatory mechanisms and their evolution with sympathetic tone usable to identify pathological conditions.
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Affiliation(s)
- Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy. Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
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44
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Stankovski T, Ticcinelli V, McClintock PVE, Stefanovska A. Neural Cross-Frequency Coupling Functions. Front Syst Neurosci 2017; 11:33. [PMID: 28663726 PMCID: PMC5471314 DOI: 10.3389/fnsys.2017.00033] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 05/04/2017] [Indexed: 11/13/2022] Open
Abstract
Although neural interactions are usually characterized only by their coupling strength and directionality, there is often a need to go beyond this by establishing the functional mechanisms of the interaction. We introduce the use of dynamical Bayesian inference for estimation of the coupling functions of neural oscillations in the presence of noise. By grouping the partial functional contributions, the coupling is decomposed into its functional components and its most important characteristics-strength and form-are quantified. The method is applied to characterize the δ-to-α phase-to-phase neural coupling functions from electroencephalographic (EEG) data of the human resting state, and the differences that arise when the eyes are either open (EO) or closed (EC) are evaluated. The δ-to-α phase-to-phase coupling functions were reconstructed, quantified, compared, and followed as they evolved in time. Using phase-shuffled surrogates to test for significance, we show how the strength of the direct coupling, and the similarity and variability of the coupling functions, characterize the EO and EC states for different regions of the brain. We confirm an earlier observation that the direct coupling is stronger during EC, and we show for the first time that the coupling function is significantly less variable. Given the current understanding of the effects of e.g., aging and dementia on δ-waves, as well as the effect of cognitive and emotional tasks on α-waves, one may expect that new insights into the neural mechanisms underlying certain diseases will be obtained from studies of coupling functions. In principle, any pair of coupled oscillations could be studied in the same way as those shown here.
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Affiliation(s)
- Tomislav Stankovski
- Nonlinear and Biomedical Physics Group, Department of Physics, Lancaster UniversityLancaster, United Kingdom
- Faculty of Medicine, Ss Cyril and Methodius UniversitySkopje, Macedonia
| | - Valentina Ticcinelli
- Nonlinear and Biomedical Physics Group, Department of Physics, Lancaster UniversityLancaster, United Kingdom
| | - Peter V. E. McClintock
- Nonlinear and Biomedical Physics Group, Department of Physics, Lancaster UniversityLancaster, United Kingdom
| | - Aneta Stefanovska
- Nonlinear and Biomedical Physics Group, Department of Physics, Lancaster UniversityLancaster, United Kingdom
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45
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Garcia-Retortillo S, Javierre C, Hristovski R, Ventura JL, Balagué N. Cardiorespiratory Coordination in Repeated Maximal Exercise. Front Physiol 2017. [PMID: 28638349 PMCID: PMC5461287 DOI: 10.3389/fphys.2017.00387] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Increases in cardiorespiratory coordination (CRC) after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC) analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate) was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1) were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax), maximal oxygen consumption (VO2 max), or ventilatory threshold (VT), an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08) was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43) in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT) between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC evaluation in the assessment and interpretation of cardiorespiratory exercise testing.
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Affiliation(s)
- Sergi Garcia-Retortillo
- Complex Systems in Sport, Institut Nacional d'Educació Física de Catalunya (INEFC), Universitat de Barcelona (UB)Barcelona, Spain.,Complex Systems in Sport, School of Health and Sport Sciences (EUSES), Universitat de GironaGirona, Spain
| | - Casimiro Javierre
- Department Physiological Sciences, Universitat de Barcelona (UB)Barcelona, Spain
| | - Robert Hristovski
- Complex Systems in Sport, Faculty of Physical Education, Sport and Health, Saints Cyril and Methodius University of SkopjeSkopje, Macedonia
| | - Josep L Ventura
- Department Physiological Sciences, Universitat de Barcelona (UB)Barcelona, Spain
| | - Natàlia Balagué
- Complex Systems in Sport, School of Health and Sport Sciences (EUSES), Universitat de GironaGirona, Spain
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46
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Stankovski T. Time-varying coupling functions: Dynamical inference and cause of synchronization transitions. Phys Rev E 2017; 95:022206. [PMID: 28297889 DOI: 10.1103/physreve.95.022206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Indexed: 12/29/2022]
Abstract
Interactions in nature can be described by their coupling strength, direction of coupling, and coupling function. The coupling strength and directionality are relatively well understood and studied, at least for two interacting systems; however, there can be a complexity in the interactions uniquely dependent on the coupling functions. Such a special case is studied here: synchronization transition occurs only due to the time variability of the coupling functions, while the net coupling strength is constant throughout the observation time. To motivate the investigation, an example is used to present an analysis of cross-frequency coupling functions between delta and alpha brain waves extracted from the electroencephalography recording of a healthy human subject in a free-running resting state. The results indicate that time-varying coupling functions are a reality for biological interactions. A model of phase oscillators is used to demonstrate and detect the synchronization transition caused by the varying coupling functions during an invariant coupling strength. The ability to detect this phenomenon is discussed with the method of dynamical Bayesian inference, which was able to infer the time-varying coupling functions. The form of the coupling function acts as an additional dimension for the interactions, and it should be taken into account when detecting biological or other interactions from data.
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Affiliation(s)
- Tomislav Stankovski
- Faculty of Medicine, Ss Cyril and Methodius University, 50 Divizija 6, Skopje 1000, Macedonia and Department of Physics, Lancaster University, Lancaster, LA1 4YB, United Kingdom
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47
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Porta A, Bari V, De Maria B, Perseguini NM, Milan J, Rehder-Santos P, Minatel V, Takahashi ACM, Catai AM. Assessing the evolution of redundancy/synergy of spontaneous variability regulation with age. Physiol Meas 2017; 38:940-958. [PMID: 28079528 DOI: 10.1088/1361-6579/aa5908] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE We exploited a model-based Wiener-Granger causality method in the information domain for the evaluation of the transfer entropy (TE) and interaction TE (ITE), the latter taken as a measure of the net balance between redundancy and synergy, to describe the interactions between the spontaneous variability of heart period (HP) and systolic arterial pressure (SAP) and the effect of respiration (R) on both variables. APPROACH Cardiac control was typified via the genuine TE from SAP to HP, that from R to HP, and the ITE from SAP and R to HP, while vascular control was characterized via the genuine TE from HP to SAP, that from R to SAP, and the ITE from HP and R to SAP. The approach was applied to study age-related modifications of cardiac and vascular controls in a cohort of 100 healthy humans (age from 21 to 70 years, 54 males) recorded at supine rest (REST) and during active standing (STAND). A surrogate approach was exploited to test the significance of the computed quantities. MAIN RESULTS Trends of the genuine information transfer with age, already present in literature, were here confirmed. We originally found that: (i) at REST redundancy was predominant over synergy in both vascular and cardiac controls; (ii) the predominance of redundancy of the cardiac control was not affected by postural challenge, while STAND reduced redundancy of vascular control; (iii) the net redundancy of the cardiac control at REST gradually decreased with age, while that of vascular control remained stable; (iv) during STAND net redundancy of both cardiac and vascular controls was stable with age. SIGNIFICANCE The study confirms the relevance of computing genuine information transfer in cardiovascular control analysis and stresses the importance of evaluating the ITE to quantify the degree of redundancy of physiological mechanisms operating to maintain cardiovascular homeostasis.
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Affiliation(s)
- Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy. Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
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48
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Mazzucco CE, Marchi A, Bari V, De Maria B, Guzzetti S, Raimondi F, Catena E, Ottolina D, Amadio C, Cravero S, Fossali T, Colombo R, Porta A. Mechanical ventilatory modes and cardioventilatory phase synchronization in acute respiratory failure patients. Physiol Meas 2017; 38:895-911. [PMID: 28052047 DOI: 10.1088/1361-6579/aa56ae] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cardioventilatory phase synchronization was studied in ten critically ill patients admitted in intensive care unit (ICU) for acute respiratory failure under two mechanical ventilatory modes: (i) pressure controlled ventilation (PCV); (ii) pressure support ventilation (PSV). The two modalities were administered to the same patient in different times in a random order. Cardioventilatory phase interactions were typified by plotting the relative position of a heartbeat, detected from the electrocardiogram and collected in n groups, within m ventilatory cycles as a function of the progressive cardiac beat number via the synchrogram. n:m phase synchronized patterns were detected by computing the variability of each phase group. The percent duration of the recording featuring phase synchronization was assessed as a measure of the strength of phase synchrony and tested against situations of full phase desynchronization between cardiac and ventilatory rhythms. Indexes quantifying the variability of the cardiac and ventilatory activities were computed as well. Findings proved that: (i) a significant presence of n:m phase synchronized patterns was detected in PCV; (ii) the strength of n:m phase synchronization was stronger during PCV than PSV; (iii) different strengths of cardioventilatory phase synchronization detected during PCV and PSV were found in presence of similar heart and ventilatory rates and alike variability. We conclude that mechanical ventilation can induce a significant presence of cardioventilatory phase synchronized patterns and this amount depends on the mode of mechanical ventilation. Future studies should test the eventual link of the level of phase coordination between heart and mechanical ventilation to a clinical outcome to understand whether featuring a certain degree of cardioventilatory phase synchronization is beneficial for the critical patient in ICU.
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Affiliation(s)
- Claudio Enrico Mazzucco
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milan, Italy
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49
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Stankovski T, Petkoski S, Raeder J, Smith AF, McClintock PVE, Stefanovska A. Alterations in the coupling functions between cortical and cardio-respiratory oscillations due to anaesthesia with propofol and sevoflurane. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0186. [PMID: 27045000 PMCID: PMC4822446 DOI: 10.1098/rsta.2015.0186] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/09/2016] [Indexed: 05/24/2023]
Abstract
The precise mechanisms underlying general anaesthesia pose important and still open questions. To address them, we have studied anaesthesia induced by the widely used (intravenous) propofol and (inhalational) sevoflurane anaesthetics, computing cross-frequency coupling functions between neuronal, cardiac and respiratory oscillations in order to determine their mutual interactions. The phase domain coupling function reveals the form of the function defining the mechanism of an interaction, as well as its coupling strength. Using a method based on dynamical Bayesian inference, we have thus identified and analysed the coupling functions for six relationships. By quantitative assessment of the forms and strengths of the couplings, we have revealed how these relationships are altered by anaesthesia, also showing that some of them are differently affected by propofol and sevoflurane. These findings, together with the novel coupling function analysis, offer a new direction in the assessment of general anaesthesia and neurophysiological interactions, in general.
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Affiliation(s)
- Tomislav Stankovski
- Department of Physics, Lancaster University, Lancaster LA1 4YB, UK Faculty of Medicine, Ss. Cyril and Methodius University, 50 Divizija 6, Skopje 1000, Macedonia
| | - Spase Petkoski
- Institut de Neurosciences des Systèmes UMR_S 1106, Aix-Marseille Université, Marseille 13005, France
| | - Johan Raeder
- Department of Anaesthesiology, Oslo University Hospital, Oslo 0424, Norway
| | - Andrew F Smith
- Department of Anaesthesia, Royal Lancaster Infirmary, Lancaster LA1 4RP, UK
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50
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Daubechies I, Wang YG, Wu HT. ConceFT: concentration of frequency and time via a multitapered synchrosqueezed transform. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:20150193. [PMID: 26953175 PMCID: PMC4792403 DOI: 10.1098/rsta.2015.0193] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A new method is proposed to determine the time-frequency content of time-dependent signals consisting of multiple oscillatory components, with time-varying amplitudes and instantaneous frequencies. Numerical experiments as well as a theoretical analysis are presented to assess its effectiveness.
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Affiliation(s)
- Ingrid Daubechies
- Department of Mathematics, Duke University, Box 90320, Durham, NC 27708-0320, USA
| | - Yi Grace Wang
- Department of Mathematics, Syracuse University, 215 Carnegie Building, Syracuse, NY 13244-1150, USA
| | - Hau-tieng Wu
- Department of Mathematics, University of Toronto, 40 St George Street, Toronto, Ontario, Canada M5S 2E4
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