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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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102
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Mastantuono T, Starita N, Battiloro L, Di Maro M, Chiurazzi M, Nasti G, Muscariello E, Cesarelli M, Iuppariello L, D'Addio G, Gorbach A, Colantuoni A, Lapi D. Laser Speckle Imaging of Rat Pial Microvasculature during Hypoperfusion-Reperfusion Damage. Front Cell Neurosci 2017; 11:298. [PMID: 28993725 PMCID: PMC5622169 DOI: 10.3389/fncel.2017.00298] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 09/06/2017] [Indexed: 11/13/2022] Open
Abstract
The present study was aimed to in vivo assess the blood flow oscillatory patterns in rat pial microvessels during 30 min bilateral common carotid artery occlusion (BCCAO) and 60 min reperfusion by laser speckle imaging (LSI). Pial microcirculation was visualized by fluorescence microscopy. The blood flow oscillations of single microvessels were recorded by LSI; spectral analysis was performed by Wavelet transform. Under baseline conditions, arterioles and venules were characterized by blood flow oscillations in the frequency ranges 0.005-0.0095 Hz, 0.0095-0.021 Hz, 0.021-0.052 Hz, 0.052-0.150 Hz and 0.150-0.500 Hz. Arterioles showed oscillations with the highest spectral density when compared with venules. Moreover, the frequency components in the ranges 0.052-0.150 Hz and 0.150-0.500 were predominant in the arteriolar total power spectrum; while, the frequency component in the range 0.150-0.500 Hz showed the highest spectral density in venules. After 30 min BCCAO, the arteriolar spectral density decreased compared to baseline; moreover, the arteriolar frequency component in the range 0.052-0.150 Hz significantly decreased in percent spectral density, while the frequency component in the range 0.150-0.500 Hz significantly increased in percent spectral density. However, an increase in arteriolar spectral density was detected at 60 min reperfusion compared to BCCAO values; consequently, an increase in percent spectral density of the frequency component in the range 0.052-0.150 Hz was observed, while the percent spectral density of the frequency component in the range 0.150-0.500 Hz significantly decreased. The remaining frequency components did not significantly change during hypoperfusion and reperfusion. The changes in blood flow during hypoperfusion/reperfusion caused tissue damage in the cortex and striatum of all animals. In conclusion, our data demonstrate that the frequency component in the range 0.052-0.150 Hz, related to myogenic activity, was significantly impaired by hypoperfusion and reperfusion, affecting cerebral blood flow distribution and causing tissue damage.
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Affiliation(s)
- Teresa Mastantuono
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Noemy Starita
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS-"Fondazione G.Pascale"Naples, Italy
| | - Laura Battiloro
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Martina Di Maro
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Martina Chiurazzi
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Gilda Nasti
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Espedita Muscariello
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Mario Cesarelli
- Department of Biomedical, Electronics and TLC Engineering, University of Naples, "Federico II"Naples, Italy
| | - Luigi Iuppariello
- Department of Biomedical, Electronics and TLC Engineering, University of Naples, "Federico II"Naples, Italy
| | | | - Alexander Gorbach
- Infrared Imaging & Thermometry Unit, NIBIB, National Institutes of HealthBethesda, MD, United States
| | - Antonio Colantuoni
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
| | - Dominga Lapi
- Department of Clinical Medicine and Surgery, "Federico II" University Medical SchoolNaples, Italy
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103
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Hodges GJ, Mallette MM, Martin ZT, Del Pozzi AT. Effect of sympathetic nerve blockade on low-frequency oscillations of forearm and leg skin blood flow in healthy humans. Microcirculation 2017. [DOI: 10.1111/micc.12388] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Gary J. Hodges
- Environmental Ergonomics Laboratory; Brock University; St Catharines ON Canada
| | - Matthew M. Mallette
- Environmental Ergonomics Laboratory; Brock University; St Catharines ON Canada
| | - Zachary T. Martin
- Integrative Exercise Physiology Laboratory; Ball State University; Muncie IN USA
| | - Andrew T. Del Pozzi
- Integrative Exercise Physiology Laboratory; Ball State University; Muncie IN USA
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104
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Ulke C, Huang J, Schwabedal JTC, Surova G, Mergl R, Hensch T. Coupling and dynamics of cortical and autonomic signals are linked to central inhibition during the wake-sleep transition. Sci Rep 2017; 7:11804. [PMID: 28924202 PMCID: PMC5603599 DOI: 10.1038/s41598-017-09513-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/25/2017] [Indexed: 01/04/2023] Open
Abstract
Maintaining temporal coordination across physiological systems is crucial at the wake-sleep transition. As shown in recent studies, the degree of coordination between brain and autonomic arousal influences attention, which highlights a previously unrecognised point of potential failure in the attention system. To investigate how cortical and autonomic dynamics are linked to the attentive process we analysed electroencephalogram, electrocardiogram and skin conductance data of 39 healthy adults recorded during a 2-h resting-state oddball experiment. We related cross-correlations to fluctuation periods of cortical and autonomic signals and correlated obtained measures to event-related potentials N1 and P2, reflecting excitatory and inhibitory processes. Increasing alignment of cortical and autonomic signals and longer periods of vigilance fluctuations corresponded to a larger and earlier P2; no such relations were found for N1. We compared two groups, with (I) and without measurable (II) delay in cortico-autonomic correlations. Individuals in Group II had more stable vigilance fluctuations, larger and earlier P2 and fell asleep more frequently than individuals in Group I. Our results support the hypothesis of a link between cortico-autonomic coupling and dynamics and central inhibition. Quantifying this link could help refine classification in psychiatric disorders with attention and sleep-related symptoms, particularly in ADHD, depression, and insomnia.
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Affiliation(s)
- Christine Ulke
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany. .,Research Center of the German Depression Foundation, Leipzig, Germany.
| | - Jue Huang
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | | | - Galina Surova
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Roland Mergl
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Tilman Hensch
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
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105
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Humeau-Heurtier A, Mahé G, Hunault G, Gascoin L, Abraham P. Multiscale Poincaré plot analysis of time series from laser speckle contrast imaging data. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2017.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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106
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Blackwood SJ, Dwyer RM, Bradley EA, Keske MA, Richards SM, Rattigan S. Determination of Skeletal Muscle Microvascular Flowmotion with Contrast-Enhanced Ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:2013-2023. [PMID: 28655467 DOI: 10.1016/j.ultrasmedbio.2017.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/29/2017] [Accepted: 05/08/2017] [Indexed: 06/07/2023]
Abstract
Most methods of assessing flowmotion (rhythmic oscillation of blood flow through tissue) are limited to small sections of tissue and are invasive in tissues other than skin. To overcome these limitations, we adapted the contrast-enhanced ultrasound (CEUS) technique to assess microvascular flowmotion throughout a large region of tissue, in a non-invasive manner and in real time. Skeletal muscle flowmotion was assessed in anaesthetised Sprague Dawley rats, using CEUS and laser Doppler flowmetry (LDF) for comparison. Wavelet transformation of CEUS and LDF data was used to quantify flowmotion. The α-adrenoceptor antagonist phentolamine was infused to predictably blunt the neurogenic component of flowmotion. Both techniques identified similar flowmotion patterns, validating the use of CEUS to assess flowmotion. This study demonstrates for the first time that the novel technique of CEUS can be adapted for determination of skeletal muscle flowmotion in large regions of skeletal muscle.
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Affiliation(s)
- Sarah J Blackwood
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
| | - Renee M Dwyer
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Eloise A Bradley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Michelle A Keske
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | | | - Stephen Rattigan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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107
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Lapi D, Varanini M, Colantuoni A, Del Seppia C, Ghione S, Fommei E, Scuri R. Repeated Mandibular Extension in Rat: A Procedure to Modulate the Cerebral Arteriolar Tone. Front Physiol 2017; 8:625. [PMID: 28912722 PMCID: PMC5583213 DOI: 10.3389/fphys.2017.00625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/11/2017] [Indexed: 11/16/2022] Open
Abstract
Previous data have shown both in the rat and in the human that a single mandibular extension lasting 10 min induces a significant important and prolonged reduction in blood pressure and heart rate, affecting also rat pial microcirculation by the release of endothelial factors. In the present work, we assessed whether repeated mandibular extension could further prolong these effects. We performed two mandibular extensions, the second mandibular extension being applied 10 min after the first one. The second mandibular extension produced a reduction in blood pressure and heart rate for at least 240 min. As in the case of a single mandibular extension, pial arterioles dilated persisting up to 140 min after the second extension. Spectral analysis on 30 min recordings under baseline conditions and after repetitive mandibular extensions showed that the pial arterioles dilation was associated with rhythmic diameter changes sustained by an increase in the frequency components related to endothelial, neurogenic, and myogenic activity while a single mandibular extension caused, conversely, an increase only in the endothelial activity. In conclusion, repetitive mandibular extension prolonged the effects of a single mandibular extension on blood pressure, heart rate and vasodilation and induced a modulation of different frequency components responsible of the pial arteriolar tone, in particular increasing the endothelial activity.
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Affiliation(s)
- Dominga Lapi
- Department of Clinical Medicine and Surgery, School of Medicine, University of Naples Federico IINaples, Italy
| | - Maurizio Varanini
- Institute of Clinical Physiology, National Council of ResearchPisa, Italy
| | - Antonio Colantuoni
- Department of Clinical Medicine and Surgery, School of Medicine, University of Naples Federico IINaples, Italy
| | | | - Sergio Ghione
- Medical and Public Health Research, Fondazione Toscana Gabriele Monasterio (CNR)Pisa, Italy
| | - Enza Fommei
- Medical and Public Health Research, Fondazione Toscana Gabriele Monasterio (CNR)Pisa, Italy
| | - Rossana Scuri
- Department of Translational Research on New Technologies in Medicine and Surgery, University of PisaPisa, Italy
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108
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Changes of Blood Flux at BL21 and Points along BL Meridian Resulted from Acupuncture or Moxibustion: Case Cross Design Study. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:8237580. [PMID: 28811830 PMCID: PMC5546059 DOI: 10.1155/2017/8237580] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/12/2017] [Accepted: 06/19/2017] [Indexed: 12/17/2022]
Abstract
Acupuncture (Acup) and moxibustion (Moxi) are commonly used interventions in clinical practice. However, the difference between Acup and moxibustion mechanisms is unclear. In current study, blood perfusion responses resulted from Acup or Moxi at Weishu acupoint (BL21) and control points were explored, respectively. The time series of blood flux signals at BL21 and control points were transformed with Morlet wavelet, and the differences in each frequency interval were observed. The results suggested that acupoint response to different stimulation is a comprehensive process which related to all components of blood perfusion signals. Whereas the different response at control points was not observed, there has been significant difference coherence value between Acup and Moxi stimulation. The results suggested the influence of Acup and Moxi not only on the level of blood perfusion at local area; the intrinsic relevance after stimulation which can be evaluated by coherence analysis is also an appropriate index to distinguish different stimulations.
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109
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Microvascular functions in patients with fibromyalgia syndrome: effects of physical exercise. Turk J Phys Med Rehabil 2017; 63:215-223. [PMID: 31453457 DOI: 10.5606/tftrd.2017.351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 09/01/2016] [Indexed: 12/31/2022] Open
Abstract
Objectives This study aims to evaluate the current state of microvascular function and to investigate the effect of supervised aerobic exercise on microvascular control mechanisms and health outcomes in women with fibromyalgia syndrome (FMS). Patients and methods Forty female patients (mean age 51±11 years) with a diagnosis of FMS according to the American College of Rheumatology criteria and 20 healthy female controls (mean age 52±9 years) were included in the study. Microvascular blood flow was measured using a laser Doppler flowmeter (LDF) at the volar skin site of the forearm. Pain severity and FMS were assessed using the visual analog scale (VAS) and Fibromyalgia Impact Questionnaire (FIQ), respectively, both at the beginnig and at the end of the study. Fibromyalgia was evaluated and a spectral analysis of LDF signals was carried out to assess the relative contribution of each control mechanisms. The local thermal hyperemia was used to test the microvascular functions. Moderate-intensity aerobic activity (energy expenditure 3.0 to 6.0 metabolic equivalent) was performed by treadmill walking for 30 min for five days each week for a month. Results The patients with FMS had lower VAS and FIQ scores at the end of the exercise period. There was a positive correlation between improved myogenic and neurogenic mechanisms and reduced FIQ scores. Cardiac signals were positively correlated with the FIQ scores at the end of the exercise period. Endothelial function was under the influence of pain, and baseline nitric oxide activity was found to be positively correlated with VAS. Conclusion Our study results suggest that microvascular functions are impaired in FMS patients and moderate exercise training is effective to improve the FIQ/VAS scores and enhance vascular functions.
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110
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Hodges GJ, Mallette MM, Tew GA, Saxton JM, Moss J, Ruddock AD, Klonizakis M. Effect of age on cutaneous vasomotor responses during local skin heating. Microvasc Res 2017; 112:47-52. [DOI: 10.1016/j.mvr.2017.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 12/19/2022]
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111
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Mizeva I, Makovik I, Dunaev A, Krupatkin A, Meglinski I. Analysis of skin blood microflow oscillations in patients with rheumatic diseases. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:70501. [PMID: 28703257 DOI: 10.1117/1.jbo.22.7.070501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 06/21/2017] [Indexed: 06/07/2023]
Abstract
Laser Doppler flowmetry (LDF) has been applied for the assessment of variation in blood microflows in patients with rheumatic diseases and healthy volunteers. Oscillations of peripheral blood microcirculation observed by LDF have been analyzed utilizing a wavelet transform. A higher amplitude of blood microflow oscillations has been observed in a high frequency band (over 0.1 Hz) in patients with rheumatic diseases. Oscillations in the high frequency band decreased in healthy volunteers in response to the cold pressor test, whereas lower frequency pulsations prevailed in patients with rheumatic diseases. A higher perfusion rate at normal conditions was observed in patients, and a weaker response to cold stimulation was observed in healthy volunteers. Analysis of blood microflow oscillations has a high potential for evaluation of mechanisms of blood flow regulation and diagnosis of vascular abnormalities associated with rheumatic diseases.
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Affiliation(s)
- Irina Mizeva
- Institute of Continuous Media Mechanics, Perm, Russia
| | - Irina Makovik
- Orel State University named after I.S. Turgenev, Orel, Russia
| | - Andrey Dunaev
- Orel State University named after I.S. Turgenev, Orel, Russia
| | - Alexander Krupatkin
- Priorov Central Scientific Research Institute of Traumatology and Orthopedics, Moscow, Russia
| | - Igor Meglinski
- University of Oulu, Opto-Electronics and Measurement Techniques, Oulu, FinlandeInstitute of Biology, Irkutsk State University, Irkutsk, RussiafITMO University, St. Petersburg, RussiagTomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
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112
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Vesoulis ZA, Hao J, McPherson C, El Ters NM, Mathur AM. Low-frequency blood pressure oscillations and inotrope treatment failure in premature infants. J Appl Physiol (1985) 2017; 123:55-61. [PMID: 28428252 PMCID: PMC6157481 DOI: 10.1152/japplphysiol.00205.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/03/2017] [Accepted: 04/13/2017] [Indexed: 11/22/2022] Open
Abstract
The underlying mechanism as to why some hypotensive preterm infants do not respond to inotropic medications remains unclear. For these infants, we hypothesize that impaired vasomotor function is a significant factor and is manifested through a decrease in low-frequency blood pressure variability across regulatory components of vascular tone. Infants born ≤28 wk estimated gestational age underwent prospective recording of mean arterial blood pressure for 72 h after birth. After error correction, root-mean-square spectral power was calculated for each valid 10-min data frame across each of four frequency bands (B1, 0.005-0.0095 Hz; B2, 0.0095-0.02 Hz; B3, 0.02-0.06 Hz; and B4, 0.06-0.16) corresponding to different components of vasomotion control. Forty infants (twenty-nine normotensive control and eleven inotrope-exposed) were included with a mean ± SD estimated gestational age of 25.2 ± 1.6 wk and birth weight 790 ± 211 g. 9.7/11.8 Million (82%) data points were error-free and used for analysis. Spectral power across all frequency bands increased with time, although the magnitude was 20% less in the inotrope-exposed infants. A statistically significant increase in spectral power in response to inotrope initiation was noted across all frequency bands. Infants with robust blood pressure response to inotropes had a greater increase compared with those who had limited or no blood pressure response. In this study, hypotensive infants who require inotropes have decreased low-frequency variability at baseline compared with normotensive infants, which increases after inotrope initiation. Low-frequency spectral power does not change for those with inotrope treatment failure, suggesting dysfunctional regulation of vascular tone as a potential mechanism of treatment failure.NEW & NOTEWORTHY In this study, we examine patterns of low-frequency oscillations in blood pressure variability across regulatory components of vascular tone in normotensive and hypotensive infants exposed to inotropic medications. We found that hypotensive infants who require inotropes have decreased low-frequency variability at baseline, which increases after inotrope initiation. Low-frequency spectral power does not change for those with inotrope treatment failure, suggesting dysfunctional regulation of vascular tone as a potential mechanism of treatment failure.
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Affiliation(s)
- Zachary A Vesoulis
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; and
| | - Jessica Hao
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; and
| | - Christopher McPherson
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; and
- St. Louis Children's Hospital, St. Louis, Missouri
| | - Nathalie M El Ters
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; and
| | - Amit M Mathur
- Division of Newborn Medicine, Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; and
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113
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Mizeva IA. Phase coherence of 0.1 Hz microvascular tone oscillations during the local heating. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1757-899x/208/1/012027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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114
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Response of Blood Perfusion at ST 36 Acupoint after Drinking Cold Glucose or Saline Injection. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:4212534. [PMID: 28465703 PMCID: PMC5390596 DOI: 10.1155/2017/4212534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/05/2017] [Indexed: 12/16/2022]
Abstract
Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in digestive system. According to acupuncture theory, change of SkBF at ST 36 might reflect the functional changes of digestive system. The aim of this study is to analyze the changes of SkBF after drinking 3°C 0.9% saline or 5% glucose injection by monitor blood flux at bilateral ST 36. The results indicated that, after drinking different cold water, the change ratio of SkBF at right side ST 36 has been different. Because all solutions have the same temperature (3°C) and both saline and glucose solution have the same osmolality, suggesting that the SkBF changes resulting from drinking cold water are not regulated just by the vagal tone and osmolality, there must have been other factors. These results have not been consistent with the frequency domain results of heart rate variability (HRV) analysis. Coherence analysis of blood flux signals at bilateral ST 36 indicated that there have been different coherence-frequency curves among different groups in special frequency bands, which suggested that coherence analysis might provide a potential tool to evaluate different status.
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115
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Tikhomirova I, Petrochenko E, Muravyov A, Malysheva Y, Petrochenko A, Yakusevich V, Oslyakova A. Microcirculation and blood rheology abnormalities in chronic heart failure. Clin Hemorheol Microcirc 2017; 65:383-391. [DOI: 10.3233/ch-16206] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Irina Tikhomirova
- Department of Medicine and Biology, Yaroslavl State Pedagogical University, Yaroslavl, Russia
| | - Elena Petrochenko
- Department of Medicine and Biology, Yaroslavl State Pedagogical University, Yaroslavl, Russia
| | - Alexei Muravyov
- Department of Medicine and Biology, Yaroslavl State Pedagogical University, Yaroslavl, Russia
| | - Yulia Malysheva
- Department of Medicine and Biology, Yaroslavl State Pedagogical University, Yaroslavl, Russia
| | - Alexandr Petrochenko
- Department of Clinical Pharmacology, Yaroslavl State Medical University, Yaroslavl, Russia
| | - Vladimir Yakusevich
- Department of Clinical Pharmacology, Yaroslavl State Medical University, Yaroslavl, Russia
| | - Anna Oslyakova
- Department of Medicine and Biology, Yaroslavl State Pedagogical University, Yaroslavl, Russia
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116
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Sorelli M, Stoyneva Z, Mizeva I, Bocchi L. Spatial heterogeneity in the time and frequency properties of skin perfusion. Physiol Meas 2017; 38:860-876. [DOI: 10.1088/1361-6579/aa5909] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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117
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Khalil A, Humeau-Heurtier A, Gascoin L, Abraham P, Mahé G. Aging effect on microcirculation: A multiscale entropy approach on laser speckle contrast images. Med Phys 2017; 43:4008. [PMID: 27370119 DOI: 10.1118/1.4953189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE It has long been known that age plays a crucial role in the deterioration of microvessels. The assessment of such deteriorations can be achieved by monitoring microvascular blood flow. Laser speckle contrast imaging (LSCI) is a powerful optical imaging tool that provides two-dimensional information on microvascular blood flow. The technique has recently been commercialized, and hence, few works discuss the postacquisition processing of laser speckle contrast images recorded in vivo. By applying entropy-based complexity measures to LSCI time series, we present herein the first attempt to study the effect of aging on microcirculation by measuring the complexity of microvascular signals over multiple time scales. METHODS Forearm skin microvascular blood flow was studied with LSCI in 18 healthy subjects. The subjects were subdivided into two age groups: younger (20-30 years old, n = 9) and older (50-68 years old, n = 9). To estimate age-dependent changes in microvascular blood flow, we applied three entropy-based complexity algorithms to LSCI time series. RESULTS The application of entropy-based complexity algorithms to LSCI time series can differentiate younger from older groups: the data fluctuations in the younger group have a significantly higher complexity than those obtained from the older group. CONCLUSIONS The effect of aging on microcirculation can be estimated by using entropy-based complexity algorithms to LSCI time series.
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Affiliation(s)
- A Khalil
- LARIS-Laboratoire Angevin de Recherche en Ingénierie des Systèmes, University of Angers, 62 Avenue Notre-Dame du Lac, Angers 49000, France
| | - A Humeau-Heurtier
- LARIS-Laboratoire Angevin de Recherche en Ingénierie des Systèmes, University of Angers, 62 Avenue Notre-Dame du Lac, Angers 49000, France
| | - L Gascoin
- Laboratoire de Physiologie et d'Explorations Vasculaires, Hospital of Angers, University of Angers, Angers Cedex 01 49033, France
| | - P Abraham
- Laboratoire de Physiologie et d'Explorations Vasculaires, Hospital of Angers, University of Angers, UMR CNRS 6214-INSERM 1083, Angers Cedex 01 49033, France
| | - G Mahé
- Pôle Imagerie Médicale et Explorations Fonctionnelles, Hospital Pontchaillou of Rennes, University of Rennes 1, INSERM CIC 1414, Rennes Cedex 9 35033, France
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118
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Antonova N, Tsiberkin K, Podtaev S, Paskova V, Velcheva I, Chaushev N. Comparative study between microvascular tone regulation and rheological properties of blood in patients with type 2 diabetes mellitus. Clin Hemorheol Microcirc 2017; 64:837-844. [DOI: 10.3233/ch-168000] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- N. Antonova
- Department of Biomechanics, Institute of Mechanics, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - K. Tsiberkin
- Department of Theoretical Physics, Perm State University, Perm, Russia
- Institute of Continuous Media Mechanics UB Russian Academy of Sciences, Perm, Russia
| | - S. Podtaev
- Institute of Continuous Media Mechanics UB Russian Academy of Sciences, Perm, Russia
| | - V. Paskova
- Department of Biomechanics, Institute of Mechanics, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - I. Velcheva
- University Hospital of Neurology and Psychiatry “St. Naum”, Medical University, Sofia, Bulgaria
| | - N. Chaushev
- University Hospital of Neurology and Psychiatry “St. Naum”, Medical University, Sofia, Bulgaria
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119
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Mallette MM, Hodges GJ, McGarr GW, Gabriel DA, Cheung SS. Spectral analysis of reflex cutaneous vasodilatation during passive heat stress. Microvasc Res 2017; 111:42-48. [PMID: 28065673 DOI: 10.1016/j.mvr.2016.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 11/19/2022]
Abstract
Previous work has demonstrated that spectral analysis is a useful tool to non-invasively ascertain the mechanisms of control of the cutaneous circulation. The majority of work using spectral analysis has focused on local control mechanisms, with none examining reflex control. Skin blood flow was analysed using spectral analysis on the dorsal aspect of the forearm of 7 males and 7 females during passive heat stress, with mean forearm and local temperature at the site of measurement maintained at thermoneutral (33°C) to minimize the effect of local control mechanisms. Participants were passively heated to ~1.2±0.1°C above baseline rectal temperature (d=4.0, P<0.001) using a water-perfused, tube lined suit, with skin blood flow assessed using a laser-Doppler probe with an integrated temperature monitor. Spectral analysis was performed using a Morlet wavelet on the entire data set, with median power extracted during 20min of data during baseline (normothermia) and hyperthermia. Passive heat stress significantly increased laser-Doppler flux above baseline (d=4.7, P<0.001). Spectral power of the endothelial nitric oxide-independent (0.005-0.01Hz; d=1.1, P=0.004), neurogenic (0.2-0.05Hz; d=0.6, P=0.025), myogenic (0.05-0.15Hz; d=1.5, P=0.002), respiratory (0.15-0.4Hz; d=1.4 P=0.002), and cardiac (0.4-2.0Hz; d=1.1, P=0.012) frequency intervals increased with passive heat stress. In contrast, the endothelial nitric oxide-dependent frequency interval did not change (0.01-0.02Hz; d=0.3, P=0.09) with passive heat stress. These data suggest that cutaneous reflex vasodilatation is neurogenic in origin and not mediated by endothelial-nitric oxide synthase, and are congruent with invasive examinations of reflex cutaneous vasodilatation.
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Affiliation(s)
- Matthew M Mallette
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Canada
| | - Gary J Hodges
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Canada
| | - Gregory W McGarr
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Canada
| | - David A Gabriel
- Electromyographic Kinesiology Laboratory, Department of Kinesiology, Brock University, St. Catharines, Canada
| | - Stephen S Cheung
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Canada.
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120
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Kuliga KZ, Gush R, Clough GF, Chipperfield AJ. Time-dependent Behavior of Microvascular Blood Flow and Oxygenation: a Predictor of Functional Outcomes. IEEE Trans Biomed Eng 2017; 65:1049-1056. [DOI: 10.1109/tbme.2017.2737328] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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121
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Combining laser-Doppler flowmetry measurements with spectral analysis to study different microcirculatory effects in human prediabetic and diabetic subjects. Lasers Med Sci 2016; 32:327-334. [DOI: 10.1007/s10103-016-2117-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 11/22/2016] [Indexed: 11/28/2022]
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122
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Humeau-Heurtier A, Wu CW, Wu SD, Mahe G, Abraham P. Refined Multiscale Hilbert–Huang Spectral Entropy and Its Application to Central and Peripheral Cardiovascular Data. IEEE Trans Biomed Eng 2016; 63:2405-2415. [DOI: 10.1109/tbme.2016.2533665] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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123
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Tikhonova IV, Kosyakova NI, Tankanag AV, Chemeris NK. Oscillations of Skin Microvascular Blood Flow in Patients with Asthma. Microcirculation 2016; 23:33-43. [PMID: 26494289 DOI: 10.1111/micc.12252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 10/19/2015] [Indexed: 02/04/2023]
Abstract
OBJECTIVE This research is aimed at studying the features of skin blood flow oscillations in patients with severe persistent atopic BA during a period of fine control over symptoms. METHODS The study of microcirculation was carried out by LDF at rest and in response to a transient ischemia in 20 patients. The time-amplitude adaptive wavelet analysis of the blood flow oscillations was conducted to elucidate the peculiarities of microcirculatory regulation system functioning. RESULTS No significant changes were revealed for SBP and the oscillation amplitudes in the cardiac (0.6-2 Hz) and respiratory (0.145-0.6 Hz) intervals, both at rest and in response to transient ischemia, in patients compared to the control group. A consistent twofold decrease in the oscillation amplitudes was found in the neurogenic (0.021-0.052 Hz) interval at rest, as well as in the myogenic (0.052-0.145 Hz) and NO-dependent endothelial (0.0095-0.021 Hz) intervals both at rest and during the postocclusive reactive hyperemia in patients with lung obstruction (FEV1 < 80%) in comparison with a control group. CONCLUSIONS The amplitudes of skin blood flow oscillations in the myogenic, neurogenic and NO-dependent endothelial intervals in patients with obstruction are different from those in patients without obstruction.
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Affiliation(s)
- Irina V Tikhonova
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Ninel I Kosyakova
- Hospital of Pushchino Scientific Center, Russian Academy of Sciences, Pushchino, Russia
| | - Arina V Tankanag
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Nikolai K Chemeris
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
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124
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Cracowski JL, Roustit M. Current Methods to Assess Human Cutaneous Blood Flow: An Updated Focus on Laser-Based-Techniques. Microcirculation 2016; 23:337-44. [DOI: 10.1111/micc.12257] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/20/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Jean-Luc Cracowski
- Université Grenoble Alpes; Grenoble France
- INSERM; Grenoble France
- Clinical Pharmacology Unit; INSERM CIC1406; Grenoble University Hospital; Grenoble France
| | - Matthieu Roustit
- Université Grenoble Alpes; Grenoble France
- INSERM; Grenoble France
- Clinical Pharmacology Unit; INSERM CIC1406; Grenoble University Hospital; Grenoble France
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125
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Age, waist circumference, and blood pressure are associated with skin microvascular flow motion: the Maastricht Study. J Hypertens 2016; 32:2439-49; discussion 2449. [PMID: 25222377 DOI: 10.1097/hjh.0000000000000348] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Skin microvascular flow motion (SMF)--blood flow fluctuation attributed to the rhythmic contraction and dilation of arterioles--is thought to be an important component of the microcirculation, by ensuring optimal delivery of nutrients and oxygen to tissue and regulating local hydraulic resistance. There is some evidence that SMF is altered in obesity, type 2 diabetes mellitus, and hypertension. Nevertheless, most studies of SMF have been conducted in highly selected patient groups, and evidence how SMF relates to other cardiovascular risk factors is scarce. Therefore, the aim of the present study was to examine in a population-based setting which cardiovascular risk factors are associated with SMF. METHODS We measured SMF in 506 participants of the Maastricht Study without prior cardiovascular event. SMF was investigated using Fourier transform analysis of skin laser Doppler flowmetry at rest within five frequency intervals in the 0.01-1.6-Hz spectral range. The associations with SMF of the cardiovascular risk factors age, sex, waist circumference, total-to-high-density lipoprotein cholesterol, fasting plasma glucose, 24-h SBP, and cigarette smoking were analysed by use of multiple linear regression analysis. RESULTS Per 1 SD higher age, waist circumference and 24-h SBP, SMF was 0.16 SD higher [95% confidence interval (CI) 0.07, 0.25; P < 0.001), -0.14 SD lower (95% CI -0.25, -0.04; P = 0.01), and 0.16 SD higher (95% CI 0.07, 0.26; P < 0.001), respectively, in fully adjusted analyses. We found no significant associations of sex, fasting plasma glucose levels, total-to-high-density lipoprotein cholesterol ratio, or pack years of smoking with SMF. CONCLUSION Age and 24-h SBP are directly, and waist circumference is inversely associated with SMF in the general population. The exact mechanisms underlying these findings remain elusive. We hypothesize that flow motion may be an important component of the microcirculation by ensuring optimal delivery of nutrients and oxygen to tissue and regulating local hydraulic resistance not only under physiological conditions but also under pathophysiological conditions when microcirculatory perfusion is reduced, such as occurs with ageing and higher blood pressure. In addition, obesity may result in an impaired flow motion with negative effects on the delivery of nutrients and oxygen to tissue and local hydraulic resistance.
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126
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Liao F, Jan YK. Using Modified Sample Entropy to Characterize Aging-Associated Microvascular Dysfunction. Front Physiol 2016; 7:126. [PMID: 27148065 PMCID: PMC4828462 DOI: 10.3389/fphys.2016.00126] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 03/22/2016] [Indexed: 11/13/2022] Open
Abstract
Cutaneous microvascular function can be assessed by skin blood flow (SBF) response to thermal stimuli. Usually, the activities of the regulatory mechanisms are quantified by means of spectral analysis of the response. However, spectral measures are unable to characterize the nonlinear dynamics of SBF signal. Sample entropy (SampEn) is a commonly used nonlinear measure of the degree of regularity of time series. However, SampEn value depends on the relationship between the frequency of the studied dynamics and sampling rate. Hence, when time series data are oversampled, SampEn may give misleading results. We modified the definition of SampEn by including a lag between successive data points of the vectors to be compared to address the oversampled issue. The lag could be chosen as the first minimum of the auto mutual information function of the time series. We tested the performance of modified SampEn using simulated signals and SBF data in the young and old groups. The results indicated that modified SampEn yields consistent results for different sampling rates in simulated data, but SampEn cannot. Blood flow data showed a higher degree of regularity during the maximal vasodilation period as compared to the baseline in both groups and a higher degree of regularity in the older group as compared to the young group. Furthermore, our results showed that during the second peak the more regular behavior of blood flow oscillations (BFO) is mainly attributed to enhanced cardiac oscillations. This study suggests that the modified SampEn approach may be useful for assessing microvascular function.
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Affiliation(s)
- Fuyuan Liao
- Department of Biomedical Engineering, Xi'an Technological UniversityXi'an, China; Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-ChampaignChampaign, IL, USA
| | - Yih-Kuen Jan
- Rehabilitation Engineering Lab, Department of Kinesiology and Community Health, University of Illinois at Urbana-ChampaignChampaign, IL, USA; Computational Science and Engineering Program, University of Illinois at Urbana-ChampaignUrbana, IL, USA
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127
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Piotrowski L, Urbaniak M, Jedrzejczak B, Marcinek A, Gebicki J. Note: Flow mediated skin fluorescence--A novel technique for evaluation of cutaneous microcirculation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:036111. [PMID: 27036844 DOI: 10.1063/1.4945044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/17/2016] [Indexed: 06/05/2023]
Abstract
This note describes a newly developed technique for evaluation of cutaneous microcirculation. The technique called Flow Mediated Skin Fluorescence (FMSF) is based on monitoring of NADH fluorescence intensity emitted from the skin tissue cells of a forearm. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. Preliminary results collected for healthy volunteers and patients experiencing serious cardiovascular problems indicated a usefulness of FMSF technique for evaluation of health related perturbations in cutaneous microcirculation.
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Affiliation(s)
- L Piotrowski
- Angionica Ltd., Zeromskiego 116, 90-924 Lodz, Poland
| | - M Urbaniak
- Institute of Applied Radiation Chemistry, Lodz University of Technology, 90-924 Lodz, Poland
| | - B Jedrzejczak
- Institute of Applied Radiation Chemistry, Lodz University of Technology, 90-924 Lodz, Poland
| | - A Marcinek
- Angionica Ltd., Zeromskiego 116, 90-924 Lodz, Poland
| | - J Gebicki
- Angionica Ltd., Zeromskiego 116, 90-924 Lodz, Poland
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128
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Del Pozzi AT, Miller JT, Hodges GJ. The effect of heating rate on the cutaneous vasomotion responses of forearm and leg skin in humans. Microvasc Res 2016; 105:77-84. [PMID: 26808211 DOI: 10.1016/j.mvr.2016.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 11/19/2022]
Abstract
We examined skin blood flow (SkBF) and vasomotion in the forearm and leg using laser-Doppler fluxmetry (LDF) and spectral analysis to investigate endothelial, sympathetic, and myogenic activities in response to slow (0.1 °C·10 s(-1)) and fast (0.5 °C·10 s(-1)) local heating. At 33 °C (thermoneutral) endothelial activity was higher in the legs than the forearms (P ≤ 0.02). Fast-heating increased SkBF more than slow heating (P=0.037 forearm; P=0.002 leg). At onset of 42 °C, endothelial (P=0.043 forearm; P=0.48 leg) activity increased in both regions during the fast-heating protocol. Following prolonged heating (42 °C) endothelial activity was higher in both the forearm (P=0.002) and leg (P<0.001) following fast-heating. These results confirm regional differences in the response to local heating and suggest that the greater increase in SkBF in response to fast local heating is initially due to increased endothelial and sympathetic activity. Furthermore, with sustained local skin heating, greater vasodilatation was observed with fast heating compared to slow heating. These data indicate that this difference is due to greater endothelial activity following fast heating compared to slow heating, suggesting that the rate of skin heating may alter the mechanisms contributing to cutaneous vasodilatation.
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Affiliation(s)
- Andrew T Del Pozzi
- Integrative Exercise Physiology Laboratory, School of Kinesiology, Ball State University, Muncie, IN 47306, United States
| | - James T Miller
- Exercise Physiology Laboratory, Department of Kinesiology, The University of Alabama, Tuscaloosa, AL 35487, United States
| | - Gary J Hodges
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada.
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129
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Abstract
Atherosclerotic coronary artery disease (CAD) is a major cause of morbidity and mortality in the developed world. Endothelial dysfunction plays an important role in the development of atherosclerosis and predicts cardiovascular (CV) outcomes independent of conventional CV risk factors. In recent years, there have been tremendous improvements in the pharmacological prevention and management of CAD. In this review, the pathophysiology of endothelial dysfunction in relation to CAD is discussed and various techniques of invasive and noninvasive assessments of peripheral and coronary endothelial function described. In addition, evidence for the association of endothelial dysfunction and CV outcomes has been examined and finally the role of therapeutic interventions in endothelial dysfunction has been discussed.
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130
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Bagno A, Martini R. Wavelet analysis of the Laser Doppler signal to assess skin perfusion. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:7374-7. [PMID: 26737995 DOI: 10.1109/embc.2015.7320095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The hemodynamics of skin microcirculation can be clinically assessed by means of Laser Doppler Fluxmetry. Laser Doppler signals show periodic oscillations because of fluctuations of microvascular perfusion (flowmotion), which are sustained by contractions and relaxations of arteriolar walls rhythmically changing vessels diameter (vasomotion). The wavelet analysis applied to Laser Doppler signals displays six characteristic frequency intervals, from 0.005 to 2 Hz. Each interval is assigned to a specific structure of the cardiovascular system: heart, respiration, vascular myocites, sympathetic terminations, and endothelial cells (dependent and independent on nitric oxide). Therefore, mechanisms of skin perfusion can be investigated through wavelet analysis. In the present work, examples of methods and results of wavelet analysis applied to Laser Doppler signals are reported. Laser Doppler signals were acquired in two groups of patients to check possible changes in vascular activities, before and after occlusive reactive hyperaemia, and before and after revascularization.
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131
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Detection of Site-Specific Blood Flow Variation in Humans during Running by a Wearable Laser Doppler Flowmeter. SENSORS 2015; 15:25507-19. [PMID: 26445047 PMCID: PMC4634506 DOI: 10.3390/s151025507] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/03/2015] [Accepted: 09/29/2015] [Indexed: 12/19/2022]
Abstract
Wearable wireless physiological sensors are helpful for monitoring and maintaining human health. Blood flow contains abundant physiological information but it is hard to measure blood flow during exercise using conventional blood flowmeters because of their size, weight, and use of optic fibers. To resolve these disadvantages, we previously developed a micro integrated laser Doppler blood flowmeter using microelectromechanical systems technology. This micro blood flowmeter is wearable and capable of stable measurement signals even during movement. Therefore, we attempted to measure skin blood flow at the forehead, fingertip, and earlobe of seven young men while running as a pilot experiment to extend the utility of the micro blood flowmeter. We measured blood flow in each subject at velocities of 6, 8, and 10 km/h. We succeeded in obtaining stable measurements of blood flow, with few motion artifacts, using the micro blood flowmeter, and the pulse wave signal and motion artifacts were clearly separated by conducting frequency analysis. Furthermore, the results showed that the extent of the changes in blood flow depended on the intensity of exercise as well as previous work with an ergometer. Thus, we demonstrated the capability of this wearable blood flow sensor for measurement during exercise.
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132
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Webb RC, Ma Y, Krishnan S, Li Y, Yoon S, Guo X, Feng X, Shi Y, Seidel M, Cho NH, Kurniawan J, Ahad J, Sheth N, Kim J, Taylor VI JG, Darlington T, Chang K, Huang W, Ayers J, Gruebele A, Pielak RM, Slepian MJ, Huang Y, Gorbach AM, Rogers JA. Epidermal devices for noninvasive, precise, and continuous mapping of macrovascular and microvascular blood flow. SCIENCE ADVANCES 2015; 1:e1500701. [PMID: 26601309 PMCID: PMC4646823 DOI: 10.1126/sciadv.1500701] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/01/2015] [Indexed: 05/17/2023]
Abstract
Continuous monitoring of variations in blood flow is vital in assessing the status of microvascular and macrovascular beds for a wide range of clinical and research scenarios. Although a variety of techniques exist, most require complete immobilization of the subject, thereby limiting their utility to hospital or clinical settings. Those that can be rendered in wearable formats suffer from limited accuracy, motion artifacts, and other shortcomings that follow from an inability to achieve intimate, noninvasive mechanical linkage of sensors with the surface of the skin. We introduce an ultrathin, soft, skin-conforming sensor technology that offers advanced capabilities in continuous and precise blood flow mapping. Systematic work establishes a set of experimental procedures and theoretical models for quantitative measurements and guidelines in design and operation. Experimental studies on human subjects, including validation with measurements performed using state-of-the-art clinical techniques, demonstrate sensitive and accurate assessment of both macrovascular and microvascular flow under a range of physiological conditions. Refined operational modes eliminate long-term drifts and reduce power consumption, thereby providing steps toward the use of this technology for continuous monitoring during daily activities.
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Affiliation(s)
- R. Chad Webb
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yinji Ma
- Departments of Civil and Environmental Engineering, and Mechanical Engineering, Center for Engineering and Health, and Skin Disease Research Center, Northwestern University, Evanston, IL 60208, USA
- Department of Engineering Mechanics, Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
| | - Siddharth Krishnan
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yuhang Li
- Departments of Civil and Environmental Engineering, and Mechanical Engineering, Center for Engineering and Health, and Skin Disease Research Center, Northwestern University, Evanston, IL 60208, USA
- Institute of Solid Mechanics, Beihang University (BUAA), Beijing 100191, China
| | - Stephen Yoon
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaogang Guo
- Departments of Civil and Environmental Engineering, and Mechanical Engineering, Center for Engineering and Health, and Skin Disease Research Center, Northwestern University, Evanston, IL 60208, USA
- College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China
| | - Xue Feng
- Department of Engineering Mechanics, Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
| | - Yan Shi
- Departments of Civil and Environmental Engineering, and Mechanical Engineering, Center for Engineering and Health, and Skin Disease Research Center, Northwestern University, Evanston, IL 60208, USA
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Miles Seidel
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nam Heon Cho
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jonas Kurniawan
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James Ahad
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Niral Sheth
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joseph Kim
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - James G. Taylor VI
- Genomic Medicine Section, Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tom Darlington
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ken Chang
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Weizhong Huang
- Department of Electrical and Computer Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Joshua Ayers
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Alexander Gruebele
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rafal M. Pielak
- L’Oréal California Research Center, 953 Indiana Street, San Francisco, CA 94107, USA
| | - Marvin J. Slepian
- Department of Medicine, Sarver Heart Center, and Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85724, USA
| | - Yonggang Huang
- Departments of Civil and Environmental Engineering, and Mechanical Engineering, Center for Engineering and Health, and Skin Disease Research Center, Northwestern University, Evanston, IL 60208, USA
| | - Alexander M. Gorbach
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - John A. Rogers
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Corresponding author. E-mail:
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Popa SO, Ferrari M, Andreozzi GM, Martini R, Bagno A. Wavelet analysis of skin perfusion to assess the effects of FREMS therapy before and after occlusive reactive hyperemia. Med Eng Phys 2015; 37:1111-5. [PMID: 26391066 DOI: 10.1016/j.medengphy.2015.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 06/03/2015] [Accepted: 08/19/2015] [Indexed: 11/30/2022]
Abstract
Laser Doppler Fluxmetry is used to evaluate the hemodynamics of skin microcirculation. Laser Doppler signals contain oscillations due to fluctuations of microvascular perfusion. By performing spectral analysis, six frequency intervals from 0.005 to 2 Hz have been identified and assigned to distinct cardiovascular structures: heart, respiration, vascular myocites, sympathetic terminations and endothelial cells (dependent and independent on nitric oxide). Transcutaneous electrical pulses are currently applied to treat several diseases, i.e. neuropathies and chronic painful leg ulcers. Recently, FREMS (Frequency Rhythmic Electrical Modulation System) has been applied to vasculopathic patients, too. In this study Laser Doppler signals of skin microcirculation were measured in five patients with intermittent claudication, before and after the FREMS therapy. Changes in vascular activities were assessed by wavelet transform analysis. Preliminary results demonstrate that FREMS induces alterations in vascular activities.
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Affiliation(s)
- Stefan Octavian Popa
- Department of Industrial Engineering, University of Padova, via Marzolo 9, 35131 Padova, Italy
| | - Myriam Ferrari
- Department of Industrial Engineering, University of Padova, via Marzolo 9, 35131 Padova, Italy
| | - Giuseppe Maria Andreozzi
- UOC of Angiology, "Azienda Ospedale" University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Romeo Martini
- UOC of Angiology, "Azienda Ospedale" University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Andrea Bagno
- Department of Industrial Engineering, University of Padova, via Marzolo 9, 35131 Padova, Italy.
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Iatsenko D, McClintock PVE, Stefanovska A. Nonlinear mode decomposition: a noise-robust, adaptive decomposition method. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:032916. [PMID: 26465549 DOI: 10.1103/physreve.92.032916] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 05/28/2023]
Abstract
The signals emanating from complex systems are usually composed of a mixture of different oscillations which, for a reliable analysis, should be separated from each other and from the inevitable background of noise. Here we introduce an adaptive decomposition tool-nonlinear mode decomposition (NMD)-which decomposes a given signal into a set of physically meaningful oscillations for any wave form, simultaneously removing the noise. NMD is based on the powerful combination of time-frequency analysis techniques-which, together with the adaptive choice of their parameters, make it extremely noise robust-and surrogate data tests used to identify interdependent oscillations and to distinguish deterministic from random activity. We illustrate the application of NMD to both simulated and real signals and demonstrate its qualitative and quantitative superiority over other approaches, such as (ensemble) empirical mode decomposition, Karhunen-Loève expansion, and independent component analysis. We point out that NMD is likely to be applicable and useful in many different areas of research, such as geophysics, finance, and the life sciences. The necessary matlab codes for running NMD are freely available for download.
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Affiliation(s)
- Dmytro Iatsenko
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | | | - Aneta Stefanovska
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
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Iredahl F, Löfberg A, Sjöberg F, Farnebo S, Tesselaar E. Non-Invasive Measurement of Skin Microvascular Response during Pharmacological and Physiological Provocations. PLoS One 2015; 10:e0133760. [PMID: 26270037 PMCID: PMC4536230 DOI: 10.1371/journal.pone.0133760] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 07/01/2015] [Indexed: 11/18/2022] Open
Abstract
Introduction Microvascular changes in the skin due to pharmacological and physiological provocations can be used as a marker for vascular function. While laser Doppler flowmetry (LDF) has been used extensively for measurement of skin microvascular responses, Laser Speckle Contrast Imaging (LSCI) and Tissue Viability Imaging (TiVi) are novel imaging techniques. TiVi measures red blood cell concentration, while LDF and LSCI measure perfusion. Therefore, the aim of this study was to compare responses to provocations in the skin using these different techniques. Method Changes in skin microcirculation were measured in healthy subjects during (1) iontophoresis of sodium nitroprusside (SNP) and noradrenaline (NA), (2) local heating and (3) post-occlusive reactive hyperemia (PORH) using LDF, LSCI and TiVi. Results Iontophoresis of SNP increased perfusion (LSCI: baseline 40.9±6.2 PU; 10-min 100±25 PU; p<0.001) and RBC concentration (TiVi: baseline 119±18; 10-min 150±41 AU; p = 0.011). No change in perfusion (LSCI) was observed after iontophoresis of NA (baseline 38.0±4.4 PU; 10-min 38.9±5.0 PU; p = 0.64), while RBC concentration decreased (TiVi: baseline 59.6±11.8 AU; 10-min 54.4±13.3 AU; p = 0.021). Local heating increased perfusion (LDF: baseline 8.8±3.6 PU; max 112±55 PU; p<0.001, LSCI: baseline 50.8±8.0 PU; max 151±22 PU; p<0.001) and RBC concentration (TiVi: baseline 49.2±32.9 AU; max 99.3±28.3 AU; p<0.001). After 5 minutes of forearm occlusion with prior exsanguination, a decrease was seen in perfusion (LDF: p = 0.027; LSCI: p<0.001) and in RBC concentration (p = 0.045). Only LSCI showed a significant decrease in perfusion after 5 minutes of occlusion without prior exsanguination (p<0.001). Coefficients of variation were lower for LSCI and TiVi compared to LDF for most responses. Conclusion LSCI is more sensitive than TiVi for measuring microvascular changes during SNP-induced vasodilatation and forearm occlusion. TiVi is more sensitive to noradrenaline-induced vasoconstriction. LSCI and TiVi show lower inter-subject variability than LDF. These findings are important to consider when choosing measurement techniques for studying skin microvascular responses.
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Affiliation(s)
- Fredrik Iredahl
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- * E-mail:
| | - Andreas Löfberg
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Folke Sjöberg
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Radiation Physics, Linköping University, Linköping, Sweden
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Han Q, Li Z, Gao Y, Li W, Xin Q, Tan Q, Zhang M, Zhang Y. Phase synchronization analysis of prefrontal tissue oxyhemoglobin oscillations in elderly subjects with cerebral infarction. Med Phys 2015; 41:102702. [PMID: 25281981 DOI: 10.1118/1.4896113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE This study aims to assess the phase relationship of prefrontal tissue oxyhemoglobin oscillations using wavelet phase coherence analysis of cerebral Delta [HbO₂] signals in cerebral infarction (CI) patients during the resting state. METHODS Continuous recordings of near-infrared spectroscopy signals were obtained from the left and right prefrontal lobes in 21 subjects with CI (Group CI, age: 76.6 ± 8.5 yr) and 21 healthy elderly subjects (Group Healthy, age: 69.0 ± 7.4 yr) during the resting state. The Group CI was further divide into two groups: CI with hypertension and CI without hypertension. The phase synchronization between left and right prefrontal Delta [HbO₂] oscillations in four frequency intervals (I, 0.6-2 Hz; II, 0.145-0.6 Hz; III, 0.052-0.145 Hz; and IV, 0.021-0.052 Hz) was analyzed using wavelet phase coherence method. RESULTS The phase coherences in intervals III and IV were significantly lower in CI with hypertension than in healthy elderly subjects (F = 12.974, p = 0.001 for III and F = 10.073, p = 0.004 for interval IV). The phase coherence of CI without hypertension in interval III was significantly lower than in healthy elderly subjects (F = 9.909, p = 0.004). Also, the phase coherence in interval IV was significantly lower in CI with hypertension than in CI without hypertension (F = 5.665, p = 0.028). Also, the phase agreement in interval IV showed evident difference between Group CI with hypertension and without hypertension. CONCLUSIONS The difference in phase characteristics of prefrontal tissue oxyhemoglobin oscillations between the CI patients and healthy elderly indicates altered phase synchronization. Moreover, the CI combined with hypertension would aggravate this process. This study provides new insight into the phase dynamics of cerebral oxygenation and may be useful in assessing the risk for stroke.
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Affiliation(s)
- Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Wenhao Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, China
| | - Qitao Tan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Manyu Zhang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Yixun Zhang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
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Abstract
Intrarenal autoregulatory mechanisms maintain renal blood flow (RBF) and glomerular filtration rate (GFR) independent of renal perfusion pressure (RPP) over a defined range (80-180 mmHg). Such autoregulation is mediated largely by the myogenic and the macula densa-tubuloglomerular feedback (MD-TGF) responses that regulate preglomerular vasomotor tone primarily of the afferent arteriole. Differences in response times allow separation of these mechanisms in the time and frequency domains. Mechanotransduction initiating the myogenic response requires a sensing mechanism activated by stretch of vascular smooth muscle cells (VSMCs) and coupled to intracellular signaling pathways eliciting plasma membrane depolarization and a rise in cytosolic free calcium concentration ([Ca(2+)]i). Proposed mechanosensors include epithelial sodium channels (ENaC), integrins, and/or transient receptor potential (TRP) channels. Increased [Ca(2+)]i occurs predominantly by Ca(2+) influx through L-type voltage-operated Ca(2+) channels (VOCC). Increased [Ca(2+)]i activates inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) to mobilize Ca(2+) from sarcoplasmic reticular stores. Myogenic vasoconstriction is sustained by increased Ca(2+) sensitivity, mediated by protein kinase C and Rho/Rho-kinase that favors a positive balance between myosin light-chain kinase and phosphatase. Increased RPP activates MD-TGF by transducing a signal of epithelial MD salt reabsorption to adjust afferent arteriolar vasoconstriction. A combination of vascular and tubular mechanisms, novel to the kidney, provides for high autoregulatory efficiency that maintains RBF and GFR, stabilizes sodium excretion, and buffers transmission of RPP to sensitive glomerular capillaries, thereby protecting against hypertensive barotrauma. A unique aspect of the myogenic response in the renal vasculature is modulation of its strength and speed by the MD-TGF and by a connecting tubule glomerular feedback (CT-GF) mechanism. Reactive oxygen species and nitric oxide are modulators of myogenic and MD-TGF mechanisms. Attenuated renal autoregulation contributes to renal damage in many, but not all, models of renal, diabetic, and hypertensive diseases. This review provides a summary of our current knowledge regarding underlying mechanisms enabling renal autoregulation in health and disease and methods used for its study.
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Affiliation(s)
- Mattias Carlström
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Christopher S Wilcox
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J Arendshorst
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Humeau-Heurtier A, Abraham P, Mahe G. Analysis of laser speckle contrast images variability using a novel empirical mode decomposition: comparison of results with laser Doppler flowmetry signals variability. IEEE TRANSACTIONS ON MEDICAL IMAGING 2015; 34:618-627. [PMID: 25347875 DOI: 10.1109/tmi.2014.2364079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) have emerged as noninvasive optical modalities to monitor microvascular blood flow. Many studies proposed to extract physiological information from LDF by analyzing signals variability. By opposition, such analyses for LSCI data have not been conducted yet. We propose to analyze LSCI variability using a novel data-driven method: the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN). CEEMDAN is suitable for nonlinear and nonstationary data and leads to intrinsic mode functions (IMFs). It is based on the ensemble empirical mode decomposition (EEMD) which relies on empirical mode decomposition (EMD). In our work the average frequencies of LSCI IMFs given by CEEMDAN are compared with the ones given by EMD and EEMD. Moreover, LDF signals acquired simultaneously to LSCI data are also processed with CEEMDAN, EMD and EEMD. We show that the average frequencies of IMFs given by CEEMDAN depend on the signal-to-noise ratio (SNR) used in the computation but, for a given SNR, the average frequencies found for LSCI are close to the ones obtained for LDF. By opposition, EEMD leads to IMFs with frequencies that do not vary much when the SNR level is higher than a threshold. The new CEEMDAN algorithm has the advantage of achieving a complete decomposition with no error in the reconstruction but our study suggests that further work is needed to gain knowledge in the adjustment of the added noise level. CEEMDAN, EMD and EEMD are data-driven methods that can provide a better knowledge of LSCI.
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140
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Mikhailichenko LA, Mezentseva LV. Correlation and spectral analysis of vascular tone regulator mechanisms in paired formations during postnatal ontogenesis in rats. Bull Exp Biol Med 2015; 158:308-12. [PMID: 25573356 DOI: 10.1007/s10517-015-2748-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Indexed: 10/24/2022]
Abstract
The study focused on the changes of microcirculation indices and components of the vascular tone of endothelial, neural, and myogenic nature in symmetrical skin sites of temples, forehead, auricles, scapulae, and groin during postnatal ontogeny. Initially, microcirculation indices in the symmetrical regions decreased to postnatal day 10, thereafter they surpassed the initial level at the age of 30 days. The endothelial, neural, and myogenic indices of vascular tone changed differently in the symmetrical left and right sites. On the right side, all indices increased by the postnatal day 21 ("redundancy" phase), and by postnatal day 30 surpassed the initial level by two times. On the left side, the redundancy phase manifested in the endothelial component on postnatal day 10, but to postnatal day 30 all three indices dropped below the initial level.
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Affiliation(s)
- L A Mikhailichenko
- Research Institute of General Pathology and Pathological Physiology, Moscow, Russia
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141
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Acupoint Activation: Response in Microcirculation and the Role of Mast Cells. MEDICINES 2014; 1:56-63. [PMID: 28933377 PMCID: PMC5532981 DOI: 10.3390/medicines1010056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/10/2014] [Accepted: 11/13/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND According to Traditional Chinese Medicine (TCM) theory, acupuncture effects are based on the integrity function of meridians. Meridians are thought to regulate body function through the normal flow of qi and/or blood. Disturbances in this flow are thought to cause disease, and acupuncture techniques are believed to cure disease by regulating this flow. However, it is still difficult to understand the exact meaning of qi and to evaluate the activation of meridians. Thus, more and more attention has been focused on the relationship of acupuncture and circulation. METHODS In this narrative review, the authors focus on the state of the art in acupoint activation, microcirculation response, and on investigation of mast cells, based on current literature research. RESULTS Altogether, 52 references are cited and discussed critically. A schematic diagram of the relationship between acupuncture stimulation, changes of microcirculation and mast cells is presented as result. CONCLUSION The block diagram presented in this review article shows that mast cells might play an important role in circulation response after acupoint stimulation.
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Gao Y, Zhang M, Han Q, Li W, Xin Q, Wang Y, Li Z. Cerebral autoregulation in response to posture change in elderly subjects-assessment by wavelet phase coherence analysis of cerebral tissue oxyhemoglobin concentrations and arterial blood pressure signals. Behav Brain Res 2014; 278:330-6. [PMID: 25453742 DOI: 10.1016/j.bbr.2014.10.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 10/07/2014] [Accepted: 10/12/2014] [Indexed: 10/24/2022]
Abstract
This study aims to assess the dynamic cerebral autoregulation (dCA) in response to posture change using wavelet phase coherence (WPCO) of cerebral tissue oxyhemoglobin concentrations (Delta [HbO2]) and arterial blood pressure (ABP) signals in healthy elderly subjects. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 16 healthy elderly subjects (age: 68.9±7.1 years) and 19 young subjects (age: 24.9±3.2 years). The phase coherence between Delta [HbO2] and ABP oscillations in six frequency intervals (I, 0.6-2 Hz; II, 0.15-0.6 Hz; III, 0.05-0.15 Hz; IV, 0.02-0.05 Hz, V, 0.0095-0.02 Hz and VI, 0.005-0.0095 Hz) was analyzed using WPCO. The sit-to-stand posture change induces significantly lower WPCO in interval III (F=5.50 p=0.025) in the elderly subjects than in the young subjects. However, the stand-to-sit posture change induces higher WPCO in intervals II (F=5.25 p=0.028) and V (F=6.22 p=0.018) in the elderly subjects than in the young subjects. The difference of WPCO in response to posture change between the elderly and the young subjects indicates an altered CA due to aging. This study provides new insight into the dynamics of CA and may be useful in identifying the risk for dCA processes.
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Affiliation(s)
- Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Wenhao Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, PR China
| | - Yan Wang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
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143
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Tankanag AV, Grinevich AA, Kirilina TV, Krasnikov GV, Piskunova GM, Chemeris NK. Wavelet phase coherence analysis of the skin blood flow oscillations in human. Microvasc Res 2014; 95:53-9. [DOI: 10.1016/j.mvr.2014.07.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/04/2014] [Accepted: 07/05/2014] [Indexed: 11/25/2022]
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144
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Zhang Z, Khatami R. Predominant endothelial vasomotor activity during human sleep: a near-infrared spectroscopy study. Eur J Neurosci 2014; 40:3396-404. [DOI: 10.1111/ejn.12702] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 07/24/2014] [Accepted: 07/29/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Zhongxing Zhang
- Center for Sleep Medicine and Sleep Research; Clinic Barmelweid; 5017 Barmelweid Switzerland
- Department of Neurology; University Hospital Zurich; Zurich Switzerland
| | - Ramin Khatami
- Center for Sleep Medicine and Sleep Research; Clinic Barmelweid; 5017 Barmelweid Switzerland
- Department of Neurology; University Hospital Zurich; Zurich Switzerland
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Han Q, Zhang M, Li W, Gao Y, Xin Q, Wang Y, Li Z. Wavelet coherence analysis of prefrontal tissue oxyhaemoglobin signals as measured using near-infrared spectroscopy in elderly subjects with cerebral infarction. Microvasc Res 2014; 95:108-15. [PMID: 25117487 DOI: 10.1016/j.mvr.2014.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/29/2014] [Accepted: 08/03/2014] [Indexed: 10/24/2022]
Abstract
This study aims to assess the prefrontal functional connectivity using wavelet coherence analysis of cerebral tissue oxyhaemoglobin concentration (Delta [HbO2]) signals in elderly subjects with cerebral infarction (CI) during the resting state. Continuous recordings of near-infrared spectroscopy (NIRS) signals were obtained from the left and right prefrontal lobes in 10 subjects with CI (age: 74.4±9.0years) and 18 healthy elderly subjects (age: 69.9±7.3years) during the resting state. The coherence between left and right prefrontal Delta [HbO2] oscillations in four frequency intervals (I, 0.6-2Hz; II, 0.145-0.6Hz; III, 0.052-0.145Hz and IV, 0.021-0.052Hz) was analyzed using wavelet coherence analysis. In healthy elderly subjects, the Delta [HbO2] oscillations were significantly wavelet coherent in intervals I and III (p<0.05), wavelet phase coherent in intervals from I to IV. In elderly subjects with CI, the left and right Delta [HbO2] oscillations were significantly wavelet coherent and phase coherent in interval I (p<0.05). In elderly subjects with CI, the power and phase coherences were significantly lower in interval III (p<0.01) than in healthy subjects. The difference in wavelet coherence between the healthy elderly and elderly with CI indicates an altered brain functional connectivity in CI patients. This may be useful for assessing the effectiveness of functional recovery following a CI.
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Affiliation(s)
- Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Wenhao Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, PR China
| | - Yan Wang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
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Kuliga KZ, McDonald EF, Gush R, Michel C, Chipperfield AJ, Clough GF. Dynamics of Microvascular Blood Flow and Oxygenation Measured Simultaneously in Human Skin. Microcirculation 2014; 21:562-73. [DOI: 10.1111/micc.12136] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/27/2014] [Indexed: 12/24/2022]
Affiliation(s)
- Katarzyna Z. Kuliga
- Human Development & Health; Faculty of Medicine; University of Southampton; Southampton UK
| | - Erin F. McDonald
- Human Development & Health; Faculty of Medicine; University of Southampton; Southampton UK
| | | | - Charles Michel
- Department of Bioengineering; Imperial College London; London UK
| | | | - Geraldine F. Clough
- Human Development & Health; Faculty of Medicine; University of Southampton; Southampton UK
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Yano T, Afroundeh R, Yamanaka R, Arimitsu T, Lian CS, Shirakawa K, Yunoki T. Oscillation in O2 uptake in impulse exercise. ACTA PHYSIOLOGICA HUNGARICA 2014; 101:143-149. [PMID: 24901075 DOI: 10.1556/aphysiol.101.2014.2.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The purpose of the present study was to examine 1) whether O(2) uptake (VO(2)) oscillates during light exercise and 2) whether the oscillation is enhanced after impulse exercise. After resting for 1 min on a bicycle seat, subjects performed 5-min pre-exercise with 25 watts work load, 10-s impulse exercise with 200 watts work load and 15-min post exercise with 25 watts work load at 80 rpm. VO(2) during pre-exercise significantly increased during impulse exercise and suddenly decreased and re-increased until 23 s after impulse exercise. In the cross correlation between heart rate (HR) and VO(2) after impulse exercise, VO(2) strongly correlated to HR with a time delay of -4 s. Peak of power spectral density (PSD) in HR appeared at 0.0039 Hz and peak of PSD in VO(2) appeared at 0.019 Hz. The peak of the cross power spectrum between VO(2) and HR appeared at 0.0078 Hz. The results suggested that there is an oscillation in O(2) uptake during light exercise that is associated with the oscillation in O(2) consumption in active muscle. The oscillation is enhanced not only by change in O(2) consumption but also by O(2) content transported from active muscle to the lungs.
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Affiliation(s)
- T Yano
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - R Afroundeh
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - R Yamanaka
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - T Arimitsu
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - C S Lian
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - K Shirakawa
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
| | - T Yunoki
- Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku, Sapporo Japan
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148
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Liang F, Yu Y, Cui S, Zhao L, Wu X. Heart motion uncertainty compensation prediction method for robot assisted beating heart surgery - Master-slave Kalman Filters approach. J Med Syst 2014; 38:52. [PMID: 24788450 DOI: 10.1007/s10916-014-0052-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/03/2014] [Indexed: 11/26/2022]
Abstract
Robot Assisted Coronary Artery Bypass Graft (CABG) allows the heart keep beating in the surgery by actively eliminating the relative motion between point of interest (POI) on the heart surface and surgical tool. The inherited nonlinear and diverse nature of beating heart motion gives a huge obstacle for the robot to meet the demanding tracking control requirements. In this paper, we novelty propose a Master-slave Kalman Filter based on beating heart motion Nonlinear Adaptive Prediction (NAP) algorithm. In the study, we describe the beating heart motion as the combination of nonlinearity relating mathematics part and uncertainty relating non-mathematics part. Specifically, first, we model the nonlinearity of the heart motion via quadratic modulated sinusoids and estimate it by a Master Kalman Filter. Second, we involve the uncertainty heart motion by adaptively change the covariance of the process noise through the slave Kalman Filter. We conduct comparative experiments to evaluate the proposed approach with four distinguished datasets. The results indicate that the new approach reduces prediction errors by at least 30 μm. Moreover, the new approach performs well in robustness test, in which two kinds of arrhythmia datasets from MIT-BIH arrhythmia database are assessed.
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Affiliation(s)
- Fan Liang
- Tianjin Key Laboratory of Information Sensing& Intelligent Control, Tianjin University of Technology and Education, Tianjin, China,
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149
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Dunaev AV, Sidorov VV, Krupatkin AI, Rafailov IE, Palmer SG, Stewart NA, Sokolovski SG, Rafailov EU. Investigating tissue respiration and skin microhaemocirculation under adaptive changes and the synchronization of blood flow and oxygen saturation rhythms. Physiol Meas 2014; 35:607-21. [DOI: 10.1088/0967-3334/35/4/607] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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150
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Cui R, Zhang M, Li Z, Xin Q, Lu L, Zhou W, Han Q, Gao Y. Wavelet coherence analysis of spontaneous oscillations in cerebral tissue oxyhemoglobin concentrations and arterial blood pressure in elderly subjects. Microvasc Res 2014; 93:14-20. [PMID: 24594440 DOI: 10.1016/j.mvr.2014.02.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 02/20/2014] [Accepted: 02/20/2014] [Indexed: 11/29/2022]
Abstract
This study aims to assess the relationship between spontaneous oscillations in changes in cerebral tissue oxyhemoglobin concentrations (Delta [HbO2]) and arterial blood pressure (ABP) signals in healthy elderly subjects during the resting state using wavelet coherence analysis. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 33 healthy elderly subjects (age: 70.7±7.9 years) and 27 young subjects (age: 25.2±3.7 years) during the resting state. The coherence between Delta [HbO2] and ABP oscillations in six frequency intervals (I, 0.4-2 Hz; II, 0.15-0.4 Hz; III, 0.05-0.15 Hz; IV, 0.02-0.05 Hz, V, 0.005-0.0095 Hz and VI, 0.005-0.0095 Hz) was analyzed using wavelet coherence analysis. In elderly subjects, the Delta [HbO2] and ABP oscillations were significantly wavelet coherent in interval I, and wavelet phase coherent in intervals I, II and IV. The wavelet coherence in interval I was significantly higher (p=0.040), in elderly subjects than in young subjects whereas that in interval V significantly lower (p=0.015). In addition, the wavelet phase coherence in interval IV was significantly higher in elderly subjects than in young subjects (p=0.028). The difference in the wavelet coherence of the elderly subjects and the young subjects indicates an altered cerebral autoregulation caused by aging. This study provides new insight into the dynamics of Delta [HbO2] and ABP oscillations and may be useful in identifying the risk for dynamic cerebral autoregulation processes.
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Affiliation(s)
- Ruofei Cui
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region P.R. China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China.
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, PR China
| | - Liqian Lu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Weiei Zhou
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
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