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Alotaibi N, Cheung M, Shah A, Hurst JR, Mani AR, Mandal S. Changes in physiological signal entropy in patients with obstructive sleep apnoea: a systematic review. Physiol Meas 2024; 45:095010. [PMID: 39260403 DOI: 10.1088/1361-6579/ad79b4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Accepted: 09/11/2024] [Indexed: 09/13/2024]
Abstract
Background and Objective.Obstructive sleep apnoea (OSA) affects an estimated 936 million people worldwide, yet only 15% receive a definitive diagnosis. Diagnosis of OSA poses challenges due to the dynamic nature of physiological signals such as oxygen saturation (SpO2) and heart rate variability (HRV). Linear analysis methods may not fully capture the irregularities present in these signals. The application of entropy of routine physiological signals offers a promising method to better measure variabilities in dynamic biological data. This review aims to explore entropy changes in physiological signals among individuals with OSA.Approach.Keyword and title searches were performed on Medline, Embase, Scopus, and CINAHL databases. Studies had to analyse physiological signals in OSA using entropy. Quality assessment used the Newcastle-Ottawa Scale. Evidence was qualitatively synthesised, considering entropy signals, entropy type, and time-series length.Main results.Twenty-two studies were included. Multiple physiological signals related to OSA, including SpO2, HRV, and the oxygen desaturation index (ODI), have been investigated using entropy. Results revealed a significant decrease in HRV entropy in those with OSA compared to control groups. Conversely, SpO2and ODI entropy values were increased in OSA. Despite variations in entropy types, time scales, and data extraction devices, studies using receiver operating characteristic curves demonstrated a high discriminative accuracy (>80% AUC) in distinguishing OSA patients from control groups.Significance. This review highlights the potential of SpO2entropy analysis in developing new diagnostic indices for patients with OSA. Further investigation is needed before applying this technique clinically.
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Affiliation(s)
- Nawal Alotaibi
- UCL Respiratory, University College London, London, United Kingdom
- Prince Sultan Military College of Health Sciences, Dhahran, Saudi Arabia
| | - Maggie Cheung
- Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Amar Shah
- UCL Respiratory, University College London, London, United Kingdom
- Royal Free London NHS Foundation Trust, London, United Kingdom
| | - John R Hurst
- UCL Respiratory, University College London, London, United Kingdom
- Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Ali R Mani
- Network Physiology Lab, University College London, London, United Kingdom
| | - Swapna Mandal
- UCL Respiratory, University College London, London, United Kingdom
- Royal Free London NHS Foundation Trust, London, United Kingdom
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Mathew AJ, Finn HT, Carter SG, Gandevia SC, Butler JE. Motor-evoked potentials in the human upper and lower limb do not increase after single 30-min sessions of acute intermittent hypoxia. J Appl Physiol (1985) 2024; 137:51-62. [PMID: 38722751 DOI: 10.1152/japplphysiol.00010.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 07/11/2024] Open
Abstract
Acute intermittent hypoxia (AIH) can induce sustained facilitation of motor output in people with spinal cord injury (SCI). Most studies of corticospinal tract excitability in humans have used 9% fraction inspired oxygen ([Formula: see text]) AIH (AIH-9%), with inconsistent outcomes. We investigated the effect of single sessions of 9% [Formula: see text] and 12% [Formula: see text] AIH (AIH-12%) on corticospinal excitability of a hand and leg muscle in able-bodied adults. Ten naïve participants completed three sessions on separate days comprising 15 epochs of 1 min of AIH-9%, AIH-12%, or sham (SHAM-21%) followed by 1 min of room air (21% [Formula: see text]) in a randomized crossover design. Motor-evoked potentials (MEPs; n = 30, ∼1 mV) elicited at rest by transcranial magnetic stimulation and maximal M-waves (Mmax) evoked by peripheral nerve stimulation were measured from the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles at baseline and at ∼0, 20, 40, and 60 min post intervention. AIH-9% induced the greatest reduction in peripheral oxygen saturation (to 85% vs. 93% and 100% in AIH-12% and SHAM-21%, respectively; P < 0.001) and the greatest increase in ventilation [by 22% vs. 12% and -3% in AIH-9%, AIH-12%, and SHAM-21%, respectively (P < 0.001)]. There was no difference in MEP amplitudes (%Mmax) after any of the three conditions (AIH-9%, AIH-12%, SHAM-21%) for both the FDI (P = 0.399) and TA (P = 0.582). Despite greater cardiorespiratory changes during AIH-9%, there was no evidence of corticospinal facilitation (tested with MEPs) in this study. Further studies could explore variability in response to AIH between individuals and other methods to measure motor facilitation in people with and without spinal cord injuries.NEW & NOTEWORTHY This is the first study that tests whether acute intermittent hypoxia (AIH) induces motor output facilitation in humans after two different doses of AIH (9% and 12% [Formula: see text]) and the reproducibility of participant responses after a repeat AIH intervention at 9% AIH. There was no motor output facilitation in response to either dose of AIH. The results question the effectiveness of a single 30-min session of AIH in inducing motor output facilitation, tested in this way.
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Affiliation(s)
- Anandit J Mathew
- Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
| | - Harrison T Finn
- Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
| | - Sophie G Carter
- Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
| | - Simon C Gandevia
- Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
- Prince of Wales Hospital, Sydney, New South Wales, Australia
| | - Jane E Butler
- Neuroscience Research Australia, Sydney, New South Wales, Australia
- University of New South Wales, Sydney, New South Wales, Australia
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Alassafi MO, Aziz W, AlGhamdi R, Alshdadi AA, Nadeem MSA, Khan IR, Bahaddad A, Altalbe A, Albishry N. Complexity reduction of oxygen saturation variability signals in COVID-19 patients: Implications for cardiorespiratory control. J Infect Public Health 2024; 17:601-608. [PMID: 38377633 DOI: 10.1016/j.jiph.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND Coronavirus disease 2019 (COVID-19) is a respiratory illness that leads to severe acute respiratory syndrome and various cardiorespiratory complications, contributing to morbidity and mortality. Entropy analysis has demonstrated its ability to monitor physiological states and system dynamics during health and disease. The main objective of the study is to extract information about cardiorespiratory control by conducting a complexity analysis of OSV signals using scale-based entropy measures following a two-month timeframe after recovery. METHODS This prospective study collected data from subjects meeting specific criteria, using a Beurer PO-80 pulse oximeter to measure oxygen saturation (SpO2) and pulse rate. Excluding individuals with a history of pulmonary/cardiovascular issues, the study analyzed 88 recordings from 44 subjects (26 men, 18 women, mean age 45.34 ± 14.40) during COVID-19 and two months post-recovery. Data preprocessing and scale-based entropy analysis were applied to assess OSV signals. RESULTS The study found a significant difference in mean OSV during illness (95.08 ± 0.15) compared to post-recovery (95.59 ± 1.03), indicating reduced cardiorespiratory dynamism during COVID-19. Multiscale entropy analyses (MSE, MPE, MFE) confirmed lower entropy values during illness across all time scales, particularly at higher scales. Notably, the maximum distinction between illness and recovery phases was seen at specific time scales and similarity criteria for each entropy measure, showing statistically significant differences. CONCLUSIONS The study demonstrates that the loss of complexity in OSV signals, quantified using scale-based entropy measures, has the potential to detect malfunctioning of cardiorespiratory control in COVID-19 patients. This finding suggests that OSV signals could serve as a valuable indicator for assessing the cardiorespiratory status of COVID-19 patients and monitoring their recovery progress.
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Affiliation(s)
- Madini O Alassafi
- Department of Information Technology, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Wajid Aziz
- Department of Computer Science and Information Technology, King Abdullah Campus, University of Azad Jammu and Kashmir, Muzaffarabad, AK, Pakistan
| | - Rayed AlGhamdi
- Department of Information Technology, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Abdulrahman A Alshdadi
- Department of Information Systems and Technology, College of Computer Science and Engineering, University of Jeddah, Saudi Arabia
| | - Malik Sajjad Ahmed Nadeem
- Department of Computer Science and Information Technology, King Abdullah Campus, University of Azad Jammu and Kashmir, Muzaffarabad, AK, Pakistan
| | | | - Adel Bahaddad
- Department of Information Technology, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ali Altalbe
- Department of Information Technology, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Nabeel Albishry
- Department of Information Technology, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
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Yang C, Liu G, Zeng X, Xiang Y, Chen X, Le W. Therapeutic effects of long-term HBOT on Alzheimer's disease neuropathologies and cognitive impairment in APP swe/PS1 dE9 mice. Redox Biol 2024; 70:103006. [PMID: 38241837 PMCID: PMC10831255 DOI: 10.1016/j.redox.2023.103006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/01/2023] [Accepted: 12/18/2023] [Indexed: 01/21/2024] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder with the pathological hallmarks of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) in the brain. Although there is a hope that anti-amyloid monoclonal antibodies may emerge as a new therapy for AD, the high cost and side effect is a big concern. Non-drug therapy is attracting more attention and may provide a better resolution for the treatment of AD. Given the fact that hypoxia contributes to the pathogenesis of AD, hyperbaric oxygen therapy (HBOT) may be an effective intervention that can alleviate hypoxia and improve AD. However, it remains unclear whether long-term HBOT intervention in the early stage of AD can slow AD progression and ultimately prevent cognitive impairment in this disease. In this study we applied consecutive 3-month HBOT interventions on 3-month-old APPswe/PS1dE9 AD mice which represent the early stage of AD. When the APPswe/PS1dE9 mice at 9-month-old which represent the disease stage we measured cognitive function, 24-h blood oxygen saturation, Aβ and tau pathologies, vascular structure and function, and neuroinflammation in APPswe/PS1dE9 mice. Our results showed that long-term HBOT can attenuate the impairments in cognitive function observed in 9-month-old APPswe/PS1dE9 mice. Most importantly, HBOT effectively reduced the progression of Aβ plaques deposition, hyperphosphorylated tau protein aggregation, and neuronal and synaptic degeneration in the AD mice. Further, long-term HBOT was able to enhance blood oxygen saturation level. Besides, long-term HBOT can improve vascular structure and function, and reduce neuroinflammation in AD mice. This study is the first to demonstrate that long-term HBOT intervention in the early stage of AD can attenuate cognitive impairment and AD-like pathologies. Overall, these findings highlight the potential of long-term HBOT as a disease-modifying approach for AD treatment.
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Affiliation(s)
- Cui Yang
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Guangdong Liu
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xianrong Zeng
- Department of Hyperbaric Oxygen, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Yang Xiang
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xi Chen
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Weidong Le
- Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China.
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Alassafi MO, Aziz W, AlGhamdi R, Alshdadi AA, Nadeem MSA, Khan IR, Albishry N, Bahaddad A, Altalbe A. Scale based entropy measures and deep learning methods for analyzing the dynamical characteristics of cardiorespiratory control system in COVID-19 subjects during and after recovery. Comput Biol Med 2024; 170:108032. [PMID: 38310805 DOI: 10.1016/j.compbiomed.2024.108032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 01/20/2024] [Accepted: 01/25/2024] [Indexed: 02/06/2024]
Abstract
COVID-19, known as Coronavirus Disease 2019 primarily targets the respiratory system and can impact the cardiovascular system, leading to a range of cardiorespiratory complications. The current forefront in analyzing the dynamical characteristics of physiological systems and aiding clinical decision-making involves the integration of entropy-based complexity techniques with artificial intelligence. Entropy-based measures offer promising prospects for identifying disturbances in cardiorespiratory control system (CRCS) among COVID-19 patients by assessing the oxygen saturation variability (OSV) signals. In this investigation, we employ scale-based entropy (SBE) methods, including multiscale entropy (MSE), multiscale permutation entropy (MPE), and multiscale fuzzy entropy (MFE), to characterize the dynamical characteristics of OSV signals. These measurements serve as features for the application of traditional machine learning (ML) and deep learning (DL) approaches in the context of classifying OSV signals from COVID-19 patients during their illness and subsequent recovery. We use the Beurer PO-80 pulse oximeter which non-invasively acquired OSV and pulse rate data from COVID-19 infected patients during the active infection phase and after a two-month recovery period. The dataset comprises of 88 recordings collected from 44 subjects(26 men and 18 women), both during their COVID-19 illness and two months post-recovery. Prior to analysis, data preprocessing is performed to remove artifacts and outliers. The application of SBE measures to OSV signals unveils a reduction in signal complexity during the course of COVID-19. Leveraging these SBE measures as feature sets, we employ two DL techniques, namely the radial basis function network (RBFN) and RBFN with dynamic delay algorithm (RBFNDDA), for the classification of OSV data collected during and after COVID-19 recovery. To evaluate the classification performance, we employ standard metrics such as sensitivity, specificity, false positive rate (FPR), and the area under the receiver operator characteristic curve (AUC). Among the three scale-based entropy measures, MFE outperformed MSE and MPE by achieving the highest classification performance using RBFN with 13 best features having sensitivity (0.84), FPR (0.30), specificity (0.70) and AUC (0.77). The outcomes of our study demonstrate that SBE measures combined with DL methods offer a valuable approach for categorizing OSV signals obtained during and after COVID-19, ultimately aiding in the detection of CRCS dysfunction.
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Affiliation(s)
- Madini O Alassafi
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Wajid Aziz
- Department of Computer Science and Information Technology, King Abdullah Campus, University of Azad Jammu and Kashmir Muzaffarabad (AK), Pakistan
| | - Rayed AlGhamdi
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia.
| | | | - Malik Sajjad Ahmed Nadeem
- Department of Computer Science and Information Technology, King Abdullah Campus, University of Azad Jammu and Kashmir Muzaffarabad (AK), Pakistan
| | | | - Nabeel Albishry
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Adel Bahaddad
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ali Altalbe
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, Saudi Arabia
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McKeown DJ, Stewart GM, Kavanagh JJ. The severity of acute hypoxaemia determines distinct changes in intracortical and spinal neural circuits. Exp Physiol 2023; 108:1203-1214. [PMID: 37548581 PMCID: PMC10988465 DOI: 10.1113/ep091224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/25/2023] [Indexed: 08/08/2023]
Abstract
The purpose of this study was to examine how two common methods of continuous hypoxaemia impact the activity of intracortical circuits responsible for inhibition and facilitation of motor output, and spinal excitability. Ten participants were exposed to 2 h of hypoxaemia at 0.13 fraction of inspired oxygen (F I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol) and 80% of peripheral capillary oxygen saturation (S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol) using a simulating altitude device on two visits separated by a week. Using transcranial magnetic and peripheral nerve stimulation, unconditioned motor evoked potential (MEP) area, short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), and F-wave persistence and area were assessed in the first dorsal interosseous (FDI) muscle before titration, after 1 and 2 h of hypoxic exposure, and at reoxygenation. The clamping protocols resulted in differing reductions inS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ by 2 h (S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol: 81.9 ± 1.3%,F I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol: 90.6 ± 2.5%). Although unconditioned MEP peak to peak amplitude and area did not differ between the protocols, SICI duringF I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping was significantly lower at 2 h compared toS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping (P = 0.011) and baseline (P < 0.001), whereas ICF was higher throughout theF I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping compared toS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping (P = 0.005). Furthermore, a negative correlation between SICI andS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ (rrm = -0.56, P = 0.002) and a positive correlation between ICF andS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ (rrm = 0.69, P = 0.001) were determined, where greater reductions inS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ correlated with less inhibition and less facilitation of MEP responses. Although F-wave area progressively increased similarly throughout the protocols (P = 0.037), persistence of responses was reduced at 2 h and reoxygenation (P < 0.01) during theS p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol compared to theF I O 2 ${F_{{\mathrm{I}}{{\mathrm{O}}_{\mathrm{2}}}}}$ clamping protocol. After 2 h of hypoxic exposure, there is a reduction in the activity of intracortical circuits responsible for inhibiting motor output, as well as excitability of spinal motoneurones. However, these effects can be influenced by other physiological responses to hypoxia (i.e., hyperventilation and hypocapnia). NEW FINDINGS: What is the central question of this study? How do two common methods of acute hypoxic exposure influence the excitability of intracortical networks and spinal circuits responsible for motor output? What is the main finding and its importance? The excitability of spinal circuits and intracortical networks responsible for inhibition of motor output was reduced during severe acute exposure to hypoxia at 2 h, but this was not seen during less severe exposure. This provides insight into the potential cause of variance seen in motor evoked potential responses to transcranial magnetic stimulation (corticospinal excitability measures) when exposed to hypoxia.
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Affiliation(s)
- Daniel J. McKeown
- Neural Control of Movement LaboratoryMenzies Health Institute QueenslandGriffith UniversityGold CoastQueenslandAustralia
- Department of PsychologyFaculty of Society and DesignBond UniversityGold CoastQueenslandAustralia
| | - Glenn M. Stewart
- Menzies Health Institute QueenslandGriffith UniversityGold CoastQueenslandAustralia
- Allied Health Research CollaborativeThe Prince Charles HospitalBrisbaneQueenslandAustralia
- Charles Perkins CentreThe University of SydneySydneyNew South WalesAustralia
| | - Justin J. Kavanagh
- Neural Control of Movement LaboratoryMenzies Health Institute QueenslandGriffith UniversityGold CoastQueenslandAustralia
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Alassafi MO, Khan IR, AlGhamdi R, Aziz W, Alshdadi AA, Dessouky MM, Bahaddad A, Altalbe A, Albishry N. Studying Dynamical Characteristics of Oxygen Saturation Variability Signals Using Haar Wavelet. Healthcare (Basel) 2023; 11:2280. [PMID: 37628478 PMCID: PMC10454822 DOI: 10.3390/healthcare11162280] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/02/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
An aim of the analysis of biomedical signals such as heart rate variability signals, brain signals, oxygen saturation variability (OSV) signals, etc., is for the design and development of tools to extract information about the underlying complexity of physiological systems, to detect physiological states, monitor health conditions over time, or predict pathological conditions. Entropy-based complexity measures are commonly used to quantify the complexity of biomedical signals; however novel complexity measures need to be explored in the context of biomedical signal classification. In this work, we present a novel technique that used Haar wavelets to analyze the complexity of OSV signals of subjects during COVID-19 infection and after recovery. The data used to evaluate the performance of the proposed algorithms comprised recordings of OSV signals from 44 COVID-19 patients during illness and after recovery. The performance of the proposed technique was compared with four, scale-based entropy measures: multiscale entropy (MSE); multiscale permutation entropy (MPE); multiscale fuzzy entropy (MFE); multiscale amplitude-aware permutation entropy (MAMPE). Preliminary results of the pilot study revealed that the proposed algorithm outperformed MSE, MPE, MFE, and MMAPE in terms of better accuracy and time efficiency for separating during and after recovery the OSV signals of COVID-19 subjects. Further studies are needed to evaluate the potential of the proposed algorithm for large datasets and in the context of other biomedical signal classifications.
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Affiliation(s)
- Madini O. Alassafi
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.O.A.); (A.B.); (A.A.); (N.A.)
| | - Ishtiaq Rasool Khan
- College of Computer Science and Engineering, University of Jeddah, Jeddah 21725, Saudi Arabia; (I.R.K.); (A.A.A.); (M.M.D.)
| | - Rayed AlGhamdi
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.O.A.); (A.B.); (A.A.); (N.A.)
| | - Wajid Aziz
- Department of Computer Science and Information Technology, King Abdullah Campus, University of Azad Jammu and Kashmir Muzaffarabad (AK), Azad Jammu and Kashmir 13100, Pakistan;
| | - Abdulrahman A. Alshdadi
- College of Computer Science and Engineering, University of Jeddah, Jeddah 21725, Saudi Arabia; (I.R.K.); (A.A.A.); (M.M.D.)
| | - Mohamed M. Dessouky
- College of Computer Science and Engineering, University of Jeddah, Jeddah 21725, Saudi Arabia; (I.R.K.); (A.A.A.); (M.M.D.)
- Department of Computer Science & Engineering, Faculty of Electronic Engineering, Menoufia University, Menouf 12548, Egypt
| | - Adel Bahaddad
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.O.A.); (A.B.); (A.A.); (N.A.)
| | - Ali Altalbe
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.O.A.); (A.B.); (A.A.); (N.A.)
| | - Nabeel Albishry
- Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.O.A.); (A.B.); (A.A.); (N.A.)
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Kohlbrenner D, Marillier M, Randy H, Ghaith A, Furian M, Vergès S. Characterisation of the acute hypoxic response using breathing variability parameters: a pilot study in humans. Respir Physiol Neurobiol 2023:104096. [PMID: 37355056 DOI: 10.1016/j.resp.2023.104096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/26/2023]
Abstract
PURPOSE We aimed to investigate respiratory rate variability (RRV) and tidal volume (Vt) variability during exposure to normobaric hypoxia (i.e., reduction in the fraction of inspired oxygen - FiO2), and the association of the changes in RRV and Vt variability with the changes in pulse oxygen saturation (SpO2). METHODS Thirty healthy human participants (15 females) were exposed to: (1) 15-min normoxia, (2) 10-min hypoxia simulating 2200m, (3) 10-min hypoxia simulating 4000m, (4) 10-min hypoxia simulating 5000m, (5) 15-min recovery in normoxia. Linear regression modelling was applied with SpO2 (dependent variable) and the changes in RRV and Vt variability (independent variables), controlling for FiO2, age, sex, changes in heart rate (HR), changes in HR variability (HRV), and changes in minute ventilation (VE). RESULTS When modelling breathing parameter variability as root-mean-square standard deviation (RMSSD), a significant independent association of the changes in RRV with the changes in SpO2 was found (B=-4.3e-04, 95% CI=-8.3e-04/-2.1e-05, p=0.04). The changes in Vt variability showed no significant association with the changes in SpO2 (B=-1.6, 95% CI=-5.5/2.4, p=0.42). When modelling parameters variability as SD, a significant independent association of the changes in RRV with the changes in SpO2 was found (B=-8.2e-04, 95% CI=-1.5e-03/-9.4e-05, p=0.03). The changes in Vt variability showed no significant association with the changes in SpO2 (B=1.4, 95% CI=-5.8/8.6, p=0.69). CONCLUSION Higher RRV is independently associated with lower SpO2 during acute hypoxic exposure, while Vt variability parameters are not. Therefore, RRV may be a potentially interesting parameter to characterize individual responses to acute hypoxia.
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Affiliation(s)
- Dario Kohlbrenner
- HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France; Faculty of Medicine, University of Zurich, Zurich, Switzerland; Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland.
| | | | - Hugo Randy
- HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France
| | - Abdallah Ghaith
- HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France
| | - Michael Furian
- HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France
| | - Samuel Vergès
- HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France
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Gheorghita M, Wikner M, Cawthorn A, Oyelade T, Nemeth K, Rockenschaub P, Gonzalez Hernandez F, Swanepoel N, Lilaonitkul W, Mani AR. Reduced oxygen saturation entropy is associated with poor prognosis in critically ill patients with sepsis. Physiol Rep 2022; 10:e15546. [PMID: 36541282 PMCID: PMC9768724 DOI: 10.14814/phy2.15546] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 11/06/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Recent studies have found that oxygen saturation (SpO2 ) variability analysis has potential for noninvasive assessment of the functional connectivity of cardiorespiratory control systems during hypoxia. Patients with sepsis have suboptimal tissue oxygenation and impaired organ system connectivity. Our objective with this report was to highlight the potential use for SpO2 variability analysis in predicting intensive care survival in patients with sepsis. MIMIC-III clinical data of 164 adults meeting Sepsis-3 criteria and with 30 min of SpO2 and respiratory rate data were analyzed. The complexity of SpO2 signals was measured through various entropy calculations such as sample entropy and multiscale entropy analysis. The sequential organ failure assessment (SOFA) score was calculated to assess the severity of sepsis and multiorgan failure. While the standard deviation of SpO2 signals was comparable in the non-survivor and survivor groups, non-survivors had significantly lower SpO2 entropy than those who survived their ICU stay (0.107 ± 0.084 vs. 0.070 ± 0.083, p < 0.05). According to Cox regression analysis, higher SpO2 entropy was a predictor of survival in patients with sepsis. Multivariate analysis also showed that the prognostic value of SpO2 entropy was independent of other covariates such as age, SOFA score, mean SpO2 , and ventilation status. When SpO2 entropy was combined with mean SpO2 , the composite had a significantly higher performance in prediction of survival. Analysis of SpO2 entropy can predict patient outcome, and when combined with SpO2 mean, can provide improved prognostic information. The prognostic power is on par with the SOFA score. This analysis can easily be incorporated into current ICU practice and has potential for noninvasive assessment of critically ill patients.
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Affiliation(s)
| | - Matthew Wikner
- Department of Perioperative Medicine and PainBarts Health NHS TrustLondonUK
| | - Anika Cawthorn
- ARC Research Software Development Group, Advanced Research Computing, UCLLondonUK
| | - Tope Oyelade
- Network Physiology Lab, Division of Medicine, UCLLondonUK
| | | | | | | | - Nel Swanepoel
- ARC Research Software Development Group, Advanced Research Computing, UCLLondonUK
| | | | - Ali R. Mani
- Network Physiology Lab, Division of Medicine, UCLLondonUK
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10
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Wang X, Huo R, Yuan W, Yuan H, Wang T, Li N. Utility of sample entropy from intraoperative cerebral NIRS oximetry data in the diagnosis of postoperative cognitive improvement. Front Physiol 2022; 13:965768. [PMID: 36246131 PMCID: PMC9558228 DOI: 10.3389/fphys.2022.965768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Appropriate monitoring and early recognition of postoperative cognitive improvement (POCI) are essential. Near-infrared spectroscopy (NIRS) showed the predictive potential of POCI. Non-linear dynamical analysis is a powerful approach for understanding intraoperative regional cerebral oxygen saturation (rSO2). Objective: We hypothesized that the sample entropy (SampEn) value of intraoperative rSO2 has the potential to predict POCI. Methods: This retrospective cohort study was conducted from June 2019 and December 2020 in a tertiary hospital in Beijing, China. A total of 126 consecutive patients who underwent carotid endarterectomy (CEA) were screened. 57 patients were included in this analysis. The primary outcome was the diagnostic accuracy of rSO2 for the prediction of POCI. Results: 33 patients (57.9%) developed POCI on postoperative day. The SampEn values of rSO2 were significantly higher in the POCI group (p < 0.05). SampEn remained an independent predictor of POCI in multivariate analysis. The area under the ROC curve (AUC) value of SampEn of rSO2 for POCI were 0.706 (95% CI, 0.569–0.843; p = 0.008). Addition of preoperative MoCA assessment and blood pressure-lowering treatment increased the AUC to 0.808 (95% CI, 0.697–0.919; p < 0.001). Conclusions: The SampEn value of rSO2 showed promise as a predictor of POCI. Non-linear analysis could be used as a supplementary method for intraoperative physiological signals.
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Affiliation(s)
- Xiaoxiao Wang
- Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing, China
| | - Ran Huo
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Wanzhong Yuan
- Department of Neurosurgery, Peking University Third Hospital, Beijing, China
| | - Huishu Yuan
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Tao Wang
- Department of Neurosurgery, Peking University Third Hospital, Beijing, China
- *Correspondence: Tao Wang, ; Nan Li,
| | - Nan Li
- Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing, China
- *Correspondence: Tao Wang, ; Nan Li,
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11
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Effects of acute intermittent hypoxia on corticospinal excitability within the primary motor cortex. Eur J Appl Physiol 2022; 122:2111-2123. [PMID: 35752660 PMCID: PMC9381468 DOI: 10.1007/s00421-022-04982-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/01/2022] [Indexed: 11/29/2022]
Abstract
Purpose Acute intermittent hypoxia (AIH) is a safe and non-invasive treatment approach that uses brief, repetitive periods of breathing reduced oxygen air alternated with normoxia. While AIH is known to affect spinal circuit excitability, the effects of AIH on cortical excitability remain largely unknown. We investigated the effects of AIH on cortical excitability within the primary motor cortex. Methods Eleven healthy, right-handed participants completed two testing sessions: (1) AIH (comprising 3 min in hypoxia [fraction of inspired oxygen ~ 10%] and 2 min in normoxia repeated over five cycles) and (2) normoxia (NOR) (equivalent duration to AIH). Single- and paired-pulse transcranial magnetic stimulations were delivered to the primary motor cortex, before and 0, 25, and 50 min after AIH and normoxia. Results The mean nadir in arterial oxygen saturation was lower (p < 0.001) during the cycles of AIH (82.5 ± 4.9%) than NOR (97.8 ± 0.6%). There was no significant difference in corticospinal excitability, intracortical facilitation, or intracortical inhibition between AIH and normoxia conditions at any time point (all p > 0.05). There was no association between arterial oxygen saturation and changes in corticospinal excitability after AIH (r = 0.05, p = 0.87). Conclusion Overall, AIH did not modify either corticospinal excitability or excitability of intracortical facilitatory and inhibitory circuits within the primary motor cortex. Future research should explore whether a more severe or individualised AIH dose would induce consistent, measurable changes in corticospinal excitability. Supplementary Information The online version contains supplementary material available at 10.1007/s00421-022-04982-8.
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12
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Behrendt T, Bielitzki R, Behrens M, Herold F, Schega L. Effects of Intermittent Hypoxia-Hyperoxia on Performance- and Health-Related Outcomes in Humans: A Systematic Review. SPORTS MEDICINE - OPEN 2022; 8:70. [PMID: 35639211 PMCID: PMC9156652 DOI: 10.1186/s40798-022-00450-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 04/17/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND Intermittent hypoxia applied at rest or in combination with exercise promotes multiple beneficial adaptations with regard to performance and health in humans. It was hypothesized that replacing normoxia by moderate hyperoxia can increase the adaptive response to the intermittent hypoxic stimulus. OBJECTIVE Our objective was to systematically review the current state of the literature on the effects of chronic intermittent hypoxia-hyperoxia (IHH) on performance- and health-related outcomes in humans. METHODS PubMed, Web of Science™, Scopus, and Cochrane Library databases were searched in accordance with PRISMA guidelines (January 2000 to September 2021) using the following inclusion criteria: (1) original research articles involving humans, (2) investigation of the chronic effect of IHH, (3) inclusion of a control group being not exposed to IHH, and (4) articles published in peer-reviewed journals written in English. RESULTS Of 1085 articles initially found, eight studies were included. IHH was solely performed at rest in different populations including geriatric patients (n = 1), older patients with cardiovascular (n = 3) and metabolic disease (n = 2) or cognitive impairment (n = 1), and young athletes with overtraining syndrome (n = 1). The included studies confirmed the beneficial effects of chronic exposure to IHH, showing improvements in exercise tolerance, peak oxygen uptake, and global cognitive functions, as well as lowered blood glucose levels. A trend was discernible that chronic exposure to IHH can trigger a reduction in systolic and diastolic blood pressure. The evidence of whether IHH exerts beneficial effects on blood lipid levels and haematological parameters is currently inconclusive. A meta-analysis was not possible because the reviewed studies had a considerable heterogeneity concerning the investigated populations and outcome parameters. CONCLUSION Based on the published literature, it can be suggested that chronic exposure to IHH might be a promising non-pharmacological intervention strategy for improving peak oxygen consumption, exercise tolerance, and cognitive performance as well as reducing blood glucose levels, and systolic and diastolic blood pressure in older patients with cardiovascular and metabolic diseases or cognitive impairment. However, further randomized controlled trials with adequate sample sizes are needed to confirm and extend the evidence. This systematic review was registered on the international prospective register of systematic reviews (PROSPERO-ID: CRD42021281248) ( https://www.crd.york.ac.uk/prospero/ ).
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Affiliation(s)
- Tom Behrendt
- Department of Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39104 Magdeburg, Germany
| | - Robert Bielitzki
- Department of Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39104 Magdeburg, Germany
| | - Martin Behrens
- Department of Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39104 Magdeburg, Germany
- Department of Orthopaedics, Rostock University Medical Center, Doberaner Str. 142, 18057 Rostock, Germany
| | - Fabian Herold
- Research Group Degenerative and Chronic Disease, Movement, Faculty of Health Sciences, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Lutz Schega
- Department of Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39104 Magdeburg, Germany
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13
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Behrendt T, Bielitzki R, Behrens M, Glazachev OS, Schega L. Effects of Intermittent Hypoxia-Hyperoxia Exposure Prior to Aerobic Cycling Exercise on Physical and Cognitive Performance in Geriatric Patients—A Randomized Controlled Trial. Front Physiol 2022; 13:899096. [PMID: 35694402 PMCID: PMC9178199 DOI: 10.3389/fphys.2022.899096] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/09/2022] [Indexed: 01/04/2023] Open
Abstract
Background: It was recently shown that intermittent hypoxic-hyperoxic exposure (IHHE) applied prior to a multimodal training program promoted additional improvements in cognitive and physical performance in geriatric patients compared to physical training only. However, there is a gap in the literature to which extent the addition of IHHE can enhance the effects of an aerobic training. Therefore, the aim of this study was to investigate the efficacy of IHHE applied prior to aerobic cycling exercise on cognitive and physical performance in geriatric patients. Methods: In a randomized, two-armed, controlled, and single-blinded trial, 25 geriatric patients (77–94 years) were assigned to two groups: intervention group (IG) and sham control group (CG). Both groups completed 6 weeks of aerobic training using a motorized cycle ergometer, three times a week for 20 min per day. The IG was additionally exposed to intermittent hypoxic and hyperoxic periods for 30 min prior to exercise. The CG followed the similar procedure breathing sham hypoxia and hyperoxia (i.e., normoxia). Within 1 week before and after the interventions, cognitive performance was assessed with the Dementia-Detection Test (DemTect) and the Clock Drawing Test (CDT), while physical performance was measured using the Timed “Up and Go” Test (TUG) and the Short-Physical-Performance-Battery (SPPB). Results: No interaction effect was found with respect to the DemTect (ηp2 = 0.02). An interaction effect with medium effect size (ηp2 = 0.08) was found for CDT performance with a higher change over time for IG (d = 0.57) compared to CG (d = 0.05). The ANCOVA with baseline-adjustment indicated between-group differences with a large and medium effect size at post-test for the TUG (ηp2 = 0.29) and SPPB (ηp2 = 0.06) performance, respectively, in favour of the IG. Within-group post-hoc analysis showed that the TUG performance was worsened in the CG (d = 0.65) and remained unchanged in the IG (d = 0.19). Furthermore, SPPB performance was increased (d = 0.58) in IG, but no relevant change over time was found for CG (d = 0.00). Conclusion: The current study suggests that an additional IHHE prior to aerobic cycling exercise seems to be more effective to increase global cognitive functions as well as physical performance and to preserve functional mobility in geriatric patients in comparison to aerobic exercise alone after a 6-week intervention period.
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Affiliation(s)
- Tom Behrendt
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- *Correspondence: Tom Behrendt,
| | - Robert Bielitzki
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Martin Behrens
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- Department of Orthopedics, Rostock University Medical Center, Rostock, Germany
| | - Oleg S. Glazachev
- Department Human Physiology, Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Lutz Schega
- Department for Sport Science, Chair for Health and Physical Activity, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
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14
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Al Rajeh A, Bhogal AS, Zhang Y, Costello JT, Hurst JR, Mani AR. Application of oxygen saturation variability analysis for the detection of exacerbation in individuals with COPD: A proof-of-concept study. Physiol Rep 2021; 9:e15132. [PMID: 34851045 PMCID: PMC8634631 DOI: 10.14814/phy2.15132] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/30/2021] [Accepted: 11/13/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Individuals with chronic obstructive pulmonary disease (COPD) commonly experience exacerbations, which may require hospital admission. Early detection of exacerbations, and therefore early treatment, could be crucial in preventing admission and improving outcomes. Our previous research has demonstrated that the pattern analysis of peripheral oxygen saturation (Sp O2 ) fluctuations provides novel insights into the engagement of the respiratory control system in response to physiological stress (hypoxia). Therefore, this pilot study tested the hypothesis that the pattern of Sp O2 variations in overnight recordings of individuals with COPD would distinguish between stable and exacerbation phases of the disease. METHODS Overnight pulse oximetry data from 11 individuals with COPD, who exhibited exacerbation after a period of stable disease, were examined. Stable phase recordings were conducted overnight and one night prior to exacerbation recordings were also analyzed. Pattern analysis of Sp O2 variations was carried examined using sample entropy (for assessment of irregularity), the multiscale entropy (complexity), and detrended fluctuation analysis (self-similarity). RESULTS Sp O2 variations displayed a complex pattern in both stable and exacerbation phases of COPD. During an exacerbation, Sp O2 entropy increased (p = 0.029) and long-term fractal-like exponent (α2) decreased (p = 0.002) while the mean and standard deviation of Sp O2 time series remained unchanged. Through ROC analyses, Sp O2 entropy and α2 were both able to classify the COPD phases into either stable or exacerbation phase. With the best positive predictor value (PPV) for sample entropy (PPV = 70%) and a cut-off value of 0.454. While the best negative predictor value (NPV) was α2 (NPV = 78%) with a cut-off value of 1.00. CONCLUSION Alterations in Sp O2 entropy and the fractal-like exponent have the potential to detect exacerbations in COPD. Further research is warranted to examine if Sp O2 variability analysis could be used as a novel objective method of detecting exacerbations.
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Affiliation(s)
- Ahmed Al Rajeh
- UCL RespiratoryRoyal Free CampusDivision of MedicineUniversity College LondonLondonUK
- Department of Respiratory CareKing Faisal UniversityAl‐AhsaSaudi Arabia
| | - Amar S. Bhogal
- Network Physiology LaboratoryDivision of MedicineUCLLondonUK
- Medical SchoolUniversity of BirminghamBirminghamUK
| | - Yunkai Zhang
- Network Physiology LaboratoryDivision of MedicineUCLLondonUK
| | - Joseph T. Costello
- Extreme Environment LaboratorySchool of Sport, Health and Exercise ScienceUniversity of PortsmouthPortsmouthUK
| | - John R Hurst
- UCL RespiratoryRoyal Free CampusDivision of MedicineUniversity College LondonLondonUK
| | - Ali R. Mani
- Network Physiology LaboratoryDivision of MedicineUCLLondonUK
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15
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Yamaguchi K, Kasai N, Hayashi N, Yatsutani H, Girard O, Goto K. Acute performance and physiological responses to repeated-sprint exercise in a combined hot and hypoxic environment. Physiol Rep 2021; 8:e14466. [PMID: 32592261 PMCID: PMC7319945 DOI: 10.14814/phy2.14466] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We investigated performance, energy metabolism, acid-base balance, and endocrine responses to repeated-sprint exercise in hot and/or hypoxic environment. In a single-blind, cross-over study, 10 male highly trained athletes completed a repeated cycle sprint exercise (3 sets of 3 × 10-s maximal sprints with 40-s passive recovery) under four conditions (control [CON; 20℃, 50% rH, FiO2 : 20.9%; sea level], hypoxia [HYP; 20℃, 50% rH, FiO2 : 14.5%; a simulated altitude of 3,000 m], hot [HOT; 35℃, 50% rH, FiO2 : 20.9%; sea level], and hot + hypoxia [HH; 35℃, 50% rH, FiO2 : 14.5%; a simulated altitude of 3,000 m]). Changes in power output, muscle and skin temperatures, and respiratory oxygen uptake were measured. Peak (CON: 912 ± 26 W, 95% confidence interval [CI]: 862-962 W, HYP: 915 ± 28 W [CI: 860-970 W], HOT: 937 ± 26 W [CI: 887-987 W], HH: 937 ± 26 W [CI: 886-987 W]) and mean (CON: 808 ± 22 W [CI: 765-851 W], HYP: 810 ± 23 W [CI: 765-855 W], HOT: 825 ± 22 W [CI: 781-868 W], HH: 824 ± 25 W [CI: 776-873 W]) power outputs were significantly greater when exercising in heat conditions (HOT and HH) during the first sprint (p < .05). Heat exposure (HOT and HH) elevated muscle and skin temperatures compared to other conditions (p < .05). Oxygen uptake and arterial oxygen saturation were significantly lower in hypoxic conditions (HYP and HH) versus the other conditions (p < .05). In summary, additional heat stress when sprinting repeatedly in hypoxia improved performance (early during exercise), while maintaining low arterial oxygen saturation.
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Affiliation(s)
- Keiichi Yamaguchi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Nobukazu Kasai
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.,Department of Sports Science, Japan Institute of Sports Sciences, Kitaku, Tokyo, Japan
| | - Nanako Hayashi
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Haruka Yatsutani
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Olivier Girard
- School of Human Science (Exercise and Sport Science), The University of Western Australia, Crawley, Australia
| | - Kazushige Goto
- Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
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16
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Masè M, Micarelli A, Strapazzon G. Hearables: New Perspectives and Pitfalls of In-Ear Devices for Physiological Monitoring. A Scoping Review. Front Physiol 2020; 11:568886. [PMID: 33178038 PMCID: PMC7596679 DOI: 10.3389/fphys.2020.568886] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/02/2020] [Indexed: 12/31/2022] Open
Abstract
Technological advancements are opening the possibility of prolonged monitoring of physiological parameters under daily-life conditions, with potential applications in sport science and medicine, and in extreme environments. Among emerging wearable technologies, in-ear devices or hearables possess technical advantages for long-term monitoring, such as non-invasivity, unobtrusivity, good fixing, and reduced motion artifacts, as well as physiological advantages related to the proximity of the ear to the body trunk and the shared vasculature between the ear and the brain. The present scoping review was aimed at identifying and synthesizing the available evidence on the use and performance of in-ear monitoring of physiological parameters, with focus on applications in sport science, sport medicine, occupational medicine, and extreme environment settings. Pubmed, Scopus, and Web of Science electronic databases were systematically searched to identify studies conducted in the last 10 years and addressing the measurement of three main physiological parameters (temperature, heart rate, and oxygen saturation) in healthy subjects. Thirty-nine studies were identified, 24 performing temperature measurement, 12 studies on heart/pulse rate, and three studies on oxygen saturation. The collected evidence supports the premise of in-ear sensors as an innovative and unobtrusive way for physiological monitoring during daily-life and physical activity, but further research and technological advancement are necessary to ameliorate measurement accuracy especially in more challenging scenarios.
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Affiliation(s)
- Michela Masè
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy.,Healthcare Research and Innovation Program, IRCS-HTA, Bruno Kessler Foundation, Trento, Italy
| | - Alessandro Micarelli
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy.,ITER Center for Balance and Rehabilitation Research (ICBRR), Rome, Italy
| | - Giacomo Strapazzon
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
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17
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Jiang Y, Costello JT, Williams TB, Panyapiean N, Bhogal AS, Tipton MJ, Corbett J, Mani AR. A network physiology approach to oxygen saturation variability during normobaric hypoxia. Exp Physiol 2020; 106:151-159. [DOI: 10.1113/ep088755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/02/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Yuji Jiang
- Network Physiology Laboratory UCL Division of Medicine University College London London UK
| | - Joseph T. Costello
- Extreme Environments Laboratory School of Sport, Health and Exercise Science University of Portsmouth Portsmouth UK
| | - Thomas B. Williams
- Extreme Environments Laboratory School of Sport, Health and Exercise Science University of Portsmouth Portsmouth UK
| | - Nawamin Panyapiean
- Network Physiology Laboratory UCL Division of Medicine University College London London UK
| | - Amar S. Bhogal
- Network Physiology Laboratory UCL Division of Medicine University College London London UK
| | - Michael J. Tipton
- Extreme Environments Laboratory School of Sport, Health and Exercise Science University of Portsmouth Portsmouth UK
| | - Jo Corbett
- Extreme Environments Laboratory School of Sport, Health and Exercise Science University of Portsmouth Portsmouth UK
| | - Ali R. Mani
- Network Physiology Laboratory UCL Division of Medicine University College London London UK
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