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Gossé LK, Pinti P, Wiesemann F, Elwell CE, Jones EJH. Developing customized NIRS-EEG for infant sleep research: methodological considerations. NEUROPHOTONICS 2023; 10:035010. [PMID: 37753324 PMCID: PMC10519625 DOI: 10.1117/1.nph.10.3.035010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 09/28/2023]
Abstract
Significance Studies using simultaneous functional near-infrared spectroscopy (fNIRS)-electroencephalography (EEG) during natural sleep in infancy are rare. Developments for combined fNIRS-EEG for sleep research that ensure optimal comfort as well as good coupling and data quality are needed. Aim We describe the steps toward developing a comfortable, wearable NIRS-EEG headgear adapted specifically for sleeping infants ages 5 to 9 months and present the experimental procedures and data quality to conduct infant sleep research using combined fNIRS-EEG. Approach N = 49 5- to 9-month-old infants participated. In phase 1, N = 26 (10 = slept) participated using the non-wearable version of the NIRS-EEG headgear with 13-channel-wearable EEG and 39-channel fiber-based NIRS. In phase 2, N = 23 infants (21 = slept) participated with the wireless version of the headgear with 20-channel-wearable EEG and 47-channel wearable NIRS. We used QT-NIRS to assess the NIRS data quality based on the good time window percentage, included channels, nap duration, and valid EEG percentage. Results The infant nap rate during phase 1 was ∼ 40 % (45% valid EEG data) and increased to 90% during phase 2 (100% valid EEG data). Infants slept significantly longer with the wearable system than the non-wearable system. However, there were more included good channels based on QT-NIRS in study phase 1 (61%) than phase 2 (50%), though this difference was not statistically significant. Conclusions We demonstrated the usability of an integrated NIRS-EEG headgear during natural infant sleep with both non-wearable and wearable NIRS systems. The wearable NIRS-EEG headgear represents a good compromise between data quality, opportunities of applications (home visits and toddlers), and experiment success (infants' comfort, longer sleep duration, and opportunities for caregiver-child interaction).
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Affiliation(s)
- Louisa K. Gossé
- Birkbeck, University of London, Centre for Brain and Cognitive Development, London, United Kingdom
| | - Paola Pinti
- Birkbeck, University of London, Centre for Brain and Cognitive Development, London, United Kingdom
| | - Frank Wiesemann
- Research and Development, Procter & Gamble, Schwalbach am Taunus, Germany
| | - Clare E. Elwell
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
| | - Emily J. H. Jones
- Birkbeck, University of London, Centre for Brain and Cognitive Development, London, United Kingdom
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2
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Ren H, Jiang X, Xu K, Chen C, Yuan Y, Dai C, Chen W. A Review of Cerebral Hemodynamics During Sleep Using Near-Infrared Spectroscopy. Front Neurol 2020; 11:524009. [PMID: 33329295 PMCID: PMC7710901 DOI: 10.3389/fneur.2020.524009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 10/26/2020] [Indexed: 11/13/2022] Open
Abstract
Investigating cerebral hemodynamic changes during regular sleep cycles and sleep disorders is fundamental to understanding the nature of physiological and pathological mechanisms in the regulation of cerebral oxygenation during sleep. Although sleep neuroimaging methods have been studied and have been well-reviewed, they have limitations in terms of technique and experimental design. Neurologists are convinced that Near-infrared spectroscopy (NIRS) provides essential information and can be used to assist the assessment of cerebral hemodynamics, and numerous studies regarding sleep have been carried out based on NIRS. Thus, a brief historical overview of the sleep studies using NIRS will be helpful for the biomedical students, academicians, and engineers to better understand NIRS from various perspectives. In this study, the existing literature on sleep studies is reviewed, and an overview of the NIRS applications is synthesized and provided. The paper first reviews the application scenarios, as well as the patterns of fluctuation of NIRS, which includes the investigation in regular sleep and sleep-disordered breathing. Various factors such as different sleep stages, populations, and degrees of severity were considered. Furthermore, the experimental design and signal processing, as well as the regulation mechanisms involved in regular and pathological sleep, are investigated and discussed. The strengths and weaknesses of the existing NIRS applications are addressed and presented, which can direct further NIRS analysis and utilization.
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Affiliation(s)
- Haoran Ren
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China
| | - Xinyu Jiang
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China
| | - Ke Xu
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China
| | - Chen Chen
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China
| | - Yafei Yuan
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China
| | - Chenyun Dai
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China
| | - Wei Chen
- The Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai, China.,Human Phenome Institute, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, Shanghai, China
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3
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Oniz A, Inanc G, Taslica S, Guducu C, Ozgoren M. Sleep Is a Refreshing Process: An fNIRS Study. Front Hum Neurosci 2019; 13:160. [PMID: 31156414 PMCID: PMC6527902 DOI: 10.3389/fnhum.2019.00160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/30/2019] [Indexed: 02/03/2023] Open
Abstract
Sleep is a very critical process that constitutes up to one third of daytime of a healthy adult. It is known to be an active period where body and brain is refreshed for the next day. It is both part of a larger cycle, i.e., circadian rhythm, and has subcsycles in it, i.e., sleep stages. Although hemodynamics of these stages have been investigated especially in the last two decades, there are still points in the hemodynamics to be illuminated especially in terms of refreshment. This study aims to investigate refreshing property of sleep in terms of sleep stages using functional near-infrared spectroscopy (fNIRS) for measuring prefrontal cortex (PFC) hemodynamics. Nine healthy subjects slept in sleep laboratories, monitored by polysomnography and fNIRS before, during, and after night sleep. REM stage had lower oxyhemoglobin (HbO) and total hemoglobin (HbT) than the other sleep stages and wakefulness. Deoxyhemoglobin (HbR) did not differ between any stages. All sleep stages and wakefulness stage at the end of the sleep had higher HbO and lower HbR than the beginning of the sleep. HbT levels did not differ between the beginning and the end of the sleep for any stages. During REM sleep, PFC seems to get lower blood supply, possibly due to increased demand in other brain regions. Regardless of the stage, PFC has higher oxygenation toward the end of sleep, indicating refreshment. Overall, our brain seems to be on duty during sleep throughout the night for “cleaning” and “refreshing” itself. Hemodynamic changes from the beginning to end of sleep might be the indicator of this work. Thus, accordingly REM stage seems to be at a central point for this work.
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Affiliation(s)
- Adile Oniz
- Department of Biophysics, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.,Sleep and Conscious States Technology Research and Application Center, Izmir, Turkey
| | - Gonca Inanc
- Department of Biophysics, Institute of Health Sciences, Dokuz Eylul University, Izmir, Turkey
| | - Serhat Taslica
- Department of Biophysics, Institute of Health Sciences, Dokuz Eylul University, Izmir, Turkey
| | - Cagdas Guducu
- Department of Biophysics, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Murat Ozgoren
- Department of Biophysics, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.,Sleep and Conscious States Technology Research and Application Center, Izmir, Turkey.,Faculty of Medicine, Near East University, Nicosia, Cyprus
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4
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Kim TJ, Lee BU, Sunwoo JS, Byun JI, Moon J, Lee ST, Jung KH, Chu K, Kim M, Lim JM, Lee E, Lee SK, Jung KY. The effect of dim light at night on cerebral hemodynamic oscillations during sleep: A near-infrared spectroscopy study. Chronobiol Int 2017; 34:1325-1338. [PMID: 29064336 DOI: 10.1080/07420528.2017.1363225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Recent studies have reported that dim light at night (dLAN) is associated with risks of cardiovascular complications, such as hypertension and carotid atherosclerosis; however, little is known about the underlying mechanism. Here, we evaluated the effect of dLAN on the cerebrovascular system by analyzing cerebral hemodynamic oscillations using near-infrared spectroscopy (NIRS). Fourteen healthy male subjects underwent polysomnography coupled with cerebral NIRS. The data collected during sleep with dim light (10 lux) were compared with those collected during sleep under the control dark conditions for the sleep structure, cerebral hemodynamic oscillations, heart rate variability (HRV), and their electroencephalographic (EEG) power spectrum. Power spectral analysis was applied to oxy-hemoglobin concentrations calculated from the NIRS signal. Spectral densities over endothelial very-low-frequency oscillations (VLFOs) (0.003-0.02 Hz), neurogenic VLFOs (0.02-0.04 Hz), myogenic low-frequency oscillations (LFOs) (0.04-0.15 Hz), and total LFOs (0.003-0.15 Hz) were obtained for each sleep stage. The polysomnographic data revealed an increase in the N2 stage under the dLAN conditions. The spectral analysis of cerebral hemodynamics showed that the total LFOs increased significantly during slow-wave sleep (SWS) and decreased during rapid eye movement (REM) sleep. Specifically, endothelial (median of normalized value, 0.46 vs. 0.72, p = 0.019) and neurogenic (median, 0.58 vs. 0.84, p = 0.019) VLFOs were enhanced during SWS, whereas endothelial VLFOs (median, 1.93 vs. 1.47, p = 0.030) were attenuated during REM sleep. HRV analysis exhibited altered spectral densities during SWS induced by dLAN, including an increase in very-low-frequency and decreases in low-frequency and high-frequency ranges. In the EEG power spectral analysis, no significant difference was detected between the control and dLAN conditions. In conclusion, dLAN can disturb cerebral hemodynamics via the endothelial and autonomic systems without cortical involvement, predominantly during SWS, which might represent an underlying mechanism of the increased cerebrovascular risk associated with light exposure during sleep.
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Affiliation(s)
- Tae-Joon Kim
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Byeong Uk Lee
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Jun-Sang Sunwoo
- b Department of Neurology , Soonchunhyang University Seoul Hospital , Seoul , South Korea
| | - Jung-Ick Byun
- c Department of Neurology , Kyung Hee University Hospital at Gangdong , Seoul , South Korea
| | - Jangsup Moon
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Soon-Tae Lee
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Keun-Hwa Jung
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Kon Chu
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Manho Kim
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea.,d Neuroscience and Protein Metabolism Medical Research Center , Seoul National University College of Medicine , Seoul , South Korea
| | - Jong-Min Lim
- e Department of Lighting Environment Research , Korea Institute of Lighting Technology , Seoul , South Korea
| | - Eunil Lee
- f Department of Preventive Medicine , Korea University College of Medicine , Seoul , South Korea
| | - Sang Kun Lee
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
| | - Ki-Young Jung
- a Department of Neurology , Seoul National University Hospital , Seoul , South Korea
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5
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Chiarelli AM, Zappasodi F, Di Pompeo F, Merla A. Simultaneous functional near-infrared spectroscopy and electroencephalography for monitoring of human brain activity and oxygenation: a review. NEUROPHOTONICS 2017; 4:041411. [PMID: 28840162 PMCID: PMC5566595 DOI: 10.1117/1.nph.4.4.041411] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/24/2017] [Indexed: 05/24/2023]
Abstract
Multimodal monitoring has become particularly common in the study of human brain function. In this context, combined, synchronous measurements of functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) are getting increased interest. Because of the absence of electro-optical interference, it is quite simple to integrate these two noninvasive recording procedures of brain activity. fNIRS and EEG are both scalp-located procedures. fNIRS estimates brain hemodynamic fluctuations relying on spectroscopic measurements, whereas EEG captures the macroscopic temporal dynamics of brain electrical activity through passive voltages evaluations. The "orthogonal" neurophysiological information provided by the two technologies and the increasing interest in the neurovascular coupling phenomenon further encourage their integration. This review provides, together with an introduction regarding the principles and future directions of the two technologies, an evaluation of major clinical and nonclinical applications of this flexible, low-cost combination of neuroimaging modalities. fNIRS-EEG systems exploit the ability of the two technologies to be conducted in an environment or experimental setting and/or on subjects that are generally not suited for other neuroimaging modalities, such as functional magnetic resonance imaging, positron emission tomography, and magnetoencephalography. fNIRS-EEG brain monitoring settles itself as a useful multimodal tool for brain electrical and hemodynamic activity investigation.
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Affiliation(s)
- Antonio M. Chiarelli
- University of Illinois at Urbana Champaign, Beckman Institute, Urbana, Illinois, United States
| | - Filippo Zappasodi
- Università G. d’Annunzio, Department of Neuroscience, Imaging and Clinical Science, Chieti, Italy
- Università G. d’Annunzio, Institute for Advanced Biomedical Technologies, Chieti, Italy
| | - Francesco Di Pompeo
- Università G. d’Annunzio, Department of Neuroscience, Imaging and Clinical Science, Chieti, Italy
- Università G. d’Annunzio, Institute for Advanced Biomedical Technologies, Chieti, Italy
| | - Arcangelo Merla
- Università G. d’Annunzio, Department of Neuroscience, Imaging and Clinical Science, Chieti, Italy
- Università G. d’Annunzio, Institute for Advanced Biomedical Technologies, Chieti, Italy
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6
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Busch DR, Lynch JM, Winters ME, McCarthy AL, Newland JJ, Ko T, Cornaglia MA, Radcliffe J, McDonough JM, Samuel J, Matthews E, Xiao R, Yodh AG, Marcus CL, Licht DJ, Tapia IE. Cerebral Blood Flow Response to Hypercapnia in Children with Obstructive Sleep Apnea Syndrome. Sleep 2016; 39:209-16. [PMID: 26414896 DOI: 10.5665/sleep.5350] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/07/2015] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Children with obstructive sleep apnea syndrome (OSAS) often experience periods of hypercapnia during sleep, a potent stimulator of cerebral blood flow (CBF). Considering this hypercapnia exposure during sleep, it is possible that children with OSAS have abnormal CBF responses to hypercapnia even during wakefulness. Therefore, we hypothesized that children with OSAS have blunted CBF response to hypercapnia during wakefulness, compared to snorers and controls. METHODS CBF changes during hypercapnic ventilatory response (HCVR) were tested in children with OSAS, snorers, and healthy controls using diffuse correlation spectroscopy (DCS). Peak CBF changes with respect to pre-hypercapnic baseline were measured for each group. The study was conducted at an academic pediatric sleep center. RESULTS Twelve children with OSAS (aged 10.1 ± 2.5 [mean ± standard deviation] y, obstructive apnea hypopnea index [AHI] = 9.4 [5.1-15.4] [median, interquartile range] events/hour), eight snorers (11 ± 3 y, 0.5 [0-1.3] events/hour), and 10 controls (11.4 ± 2.6 y, 0.3 [0.2-0.4] events/hour) were studied. The fractional CBF change during hypercapnia, normalized to the change in end-tidal carbon dioxide, was significantly higher in controls (9 ± 1.8 %/mmHg) compared to OSAS (7.1 ± 1.5, P = 0.023) and snorers (6.7 ± 1.9, P = 0.025). CONCLUSIONS Children with OSAS and snorers have blunted CBF response to hypercapnia during wakefulness compared to controls. Noninvasive DCS blood flow measurements of hypercapnic reactivity offer insights into physiopathology of OSAS in children, which could lead to further understanding about the central nervous system complications of OSAS.
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Affiliation(s)
- David R Busch
- Division of Neurology, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.,Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA
| | - Jennifer M Lynch
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA
| | - Madeline E Winters
- Division of Neurology, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | - John J Newland
- Division of Neurology, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Tiffany Ko
- Department of Biomedical Engineering, University of Pennsylvania, Philadelphia, PA
| | - Mary Anne Cornaglia
- The Sleep Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Jerilynn Radcliffe
- Clinical and Translational Research Center, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Joseph M McDonough
- The Sleep Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - John Samuel
- The Sleep Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Edward Matthews
- The Sleep Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Rui Xiao
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA
| | - Arjun G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA
| | - Carole L Marcus
- The Sleep Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Daniel J Licht
- Division of Neurology, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Ignacio E Tapia
- The Sleep Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
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7
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A New Approach for Automatic Removal of Movement Artifacts in Near-Infrared Spectroscopy Time Series by Means of Acceleration Data. ALGORITHMS 2015. [DOI: 10.3390/a8041052] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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8
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Zhang Z, Khatami R. A Biphasic Change of Regional Blood Volume in the Frontal Cortex during Non-Rapid Eye Movement Sleep: A Near-Infrared Spectroscopy Study. Sleep 2015; 38:1211-7. [PMID: 25761983 DOI: 10.5665/sleep.4894] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 01/16/2015] [Indexed: 12/29/2022] Open
Abstract
STUDY OBJECTIVES Current knowledge on hemodynamics in sleep is limited because available techniques do not allow continuous recordings and mainly focus on cerebral blood flow while neglecting other important parameters, such as blood volume (BV) and vasomotor activity. DESIGN Observational study. PARTICIPANTS AND SETTINGS Continuous measures of hemodynamics over the left forehead and biceps were performed using near-infrared spectroscopy (NIRS) during nocturnal polysomnography in 16 healthy participants in sleep laboratory. MEASUREMENTS AND RESULTS Temporal dynamics and mean values of cerebral and muscular oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HHb), and BV during different sleep stages were compared. A biphasic change of cerebral BV was observed which contrasted a monotonic increase of muscular BV during non-rapid eye movement sleep. A significant decrement in cerebral HbO2 and BV accompanied by an increase of HHb was recorded at sleep onset (Phase I). Prior to slow wave sleep (SWS) HbO2 and BV turned to increase whereas HHb began to decrease in subsequent Phase II suggested increased brain perfusion during SWS. The cerebral HbO2 slope correlated to BV slope in Phase I and II, but it only correlated to HHb slope in Phase II. The occurrence time of inflection points correlated to SWS latencies. CONCLUSION Initial decrease of brain perfusion with decreased blood volume (BV) and oxygenated hemoglobin (HbO2) together with increasing muscular BV fit thermoregulation process at sleep onset. The uncorrelated and correlated slopes of HbO2 and deoxygenated hemoglobin indicate different mechanisms underlying the biphasic hemodynamic process in light sleep and slow wave sleep (SWS). In SWS, changes in vasomotor activity (i.e., increased vasodilatation) may mediate increasing cerebral and muscular BV.
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Affiliation(s)
- Zhongxing Zhang
- Center for Sleep Medicine and Sleep Research, Clinic Barmelweid, Barmelweid, Switzerland.,Department of Neurology, University Hospital Bern, Bern, Switzerland
| | - Ramin Khatami
- Center for Sleep Medicine and Sleep Research, Clinic Barmelweid, Barmelweid, Switzerland.,Department of Neurology, University Hospital Bern, Bern, Switzerland.,ZIHP, Zurich Center for Integrative Human Physiology, Zürich, Switzerland
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9
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Pearce I. Entoptic perceptions of spiral waves and rare inward spirals. CHAOS (WOODBURY, N.Y.) 2015; 25:063109. [PMID: 26117103 DOI: 10.1063/1.4922253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This report concerns Entoptic Rotating Spiral Waves as observed and documented by the author over a period of 46 years (1962-2008). The manifestations of these state-dependent, elusive rotating spiral entities were brief, emerging only during sleep-to-waking arousal epochs (in limbo). The images were seen only with closed lids in favorable ambient lighting-here, termed the umbral view. The clusters of rotating spiral entities emerge briefly to conscious view; their angular subtenses are estimated to be between 1° and 4°, and the rotations at ten-turns per second. Epochs of these activities commonly continued for about 20 s, with longevity of each visible entity up to 4 s. 90% of all observed entities were circular and outwardly levorotary; 5% were elliptical, appearing only as horizontal (prolate) entities. Overlapping units were rare, and were chiefly elliptical. Observations of twin spirals were also rare, seen in counter rotations, each twin inwardly rotating.
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Affiliation(s)
- Ida Pearce
- Diplomate in Ophthalmology, 1951, Royal College of Surgeons of England, Clinical at Moorfields, and the Royal Eye Hospital, London
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10
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Yuan QY, Zhang L, Xiao D, Zhao K, Lin C, Si LY. An accurate, flexible and small optical fiber sensor: a novel technological breakthrough for real-time analysis of dynamic blood flow data in vivo. PLoS One 2014; 9:e114794. [PMID: 25551384 PMCID: PMC4281125 DOI: 10.1371/journal.pone.0114794] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 11/13/2014] [Indexed: 12/01/2022] Open
Abstract
Because of the limitations of existing methods and techniques for directly obtaining real-time blood data, no accurate microflow in vivo real-time analysis method exists. To establish a novel technical platform for real-time in vivo detection and to analyze average blood pressure and other blood flow parameters, a small, accurate, flexible, and nontoxic Fabry-Perot fiber sensor was designed. The carotid sheath was implanted through intubation of the rabbit carotid artery (n = 8), and the blood pressure and other detection data were determined directly through the veins. The fiber detection results were compared with test results obtained using color Doppler ultrasound and a physiological pressure sensor recorder. Pairwise comparisons among the blood pressure results obtained using the three methods indicated that real-time blood pressure information obtained through the fiber sensor technique exhibited better correlation than the data obtained with the other techniques. The highest correlation (correlation coefficient of 0.86) was obtained between the fiber sensor and pressure sensor. The blood pressure values were positively related to the total cholesterol level, low-density lipoprotein level, number of red blood cells, and hemoglobin level, with correlation coefficients of 0.033, 0.129, 0.358, and 0.373, respectively. The blood pressure values had no obvious relationship with the number of white blood cells and high-density lipoprotein and had a negative relationship with triglyceride levels, with a correlation coefficient of –0.031. The average ambulatory blood pressure measured by the fiber sensor exhibited a negative correlation with the quantity of blood platelets (correlation coefficient of −0.839, P<0.05). The novel fiber sensor can thus obtain in vivo blood pressure data accurately, stably, and in real time; the sensor can also determine the content and status of the blood flow to some extent. Therefore, the fiber sensor can obtain partially real-time vascular rheology information and may thus enable the early diagnosis of blood rheology disorders and diseases.
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Affiliation(s)
- Qiao-ying Yuan
- Department of Geriatrics, Southwest Hospital, the Third Military Medical University, Chongqing, PR China
| | - Ling Zhang
- Department of Out-patient clinic (OPD), Southwest hospital, the Third Military Medical University, Chongqing, PR China
| | - Dan Xiao
- Department of Geriatrics, Southwest Hospital, the Third Military Medical University, Chongqing, PR China
| | - Kun Zhao
- Department of Geriatrics, Southwest Hospital, the Third Military Medical University, Chongqing, PR China
| | - Chun Lin
- School of Physics and Mechanical & Electrical Engineering, Xiamen University, Xiamen, PR China
| | - Liang-yi Si
- Department of Geriatrics, Southwest Hospital, the Third Military Medical University, Chongqing, PR China
- * E-mail:
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11
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Metz AJ, Pugin F, Huber R, Achermann P, Wolf M. Changes of cerebral tissue oxygen saturation at sleep transitions in adolescents. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 812:279-285. [PMID: 24729244 DOI: 10.1007/978-1-4939-0620-8_37] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
In adults, cerebral oxy-([O₂Hb]) and deoxyhemoglobin concentrations ([HHb]) change characteristically at transitions of sleep stages. The aims were to assess these changes in adolescents and additionally to measure tissue oxygen saturation (StO₂) by near infrared spectroscopy (NIRS). Previously it was reported that in adults [O₂Hb] increased and [HHb] decreased at the transition from non-rapid eye movement sleep (NREMS) to REMS and wakefulness. Transitions to NREMS from REMS/wakefulness led to a decrease in [O₂Hb] and an increase in [HHb]. We measured [O₂Hb], [HHb] and tissue oxygenation (StO₂) with NIRS approximately above the left prefrontal cortex in 12 healthy adolescent males (aged 10-16 years). We found comparable signs and magnitudes of changes in [O₂Hb] and [HHb] as observed in adults. StO₂ increased at the transitions from NREMS to REMS and decreased from REMS to NREMS and at sleep onset (all p < 0.01, linear mixed effects model). Changes in oxygen metabolism during sleep transitions are similar in adolescents and adults. In addition, we show for the first time temporal changes of StO₂ at sleep transitions.
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Affiliation(s)
- Andreas J Metz
- Biomedical Optics Research Laboratory, Division of Neonatology, University Hospital Zurich, Frauenklinikstasse 10, 8091, Zurich, Switzerland. .,Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland.
| | - F Pugin
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - R Huber
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - P Achermann
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Institute of Pharmacology and Toxicology, Chronobiology and Sleep Research, University of Zurich, Zurich, Switzerland
| | - M Wolf
- Biomedical Optics Research Laboratory, Division of Neonatology, University Hospital Zurich, Frauenklinikstasse 10, 8091, Zurich, Switzerland.,Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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12
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Zhang Q, Ivkovic V, Hu G, Strangman GE. Twenty-four-hour ambulatory recording of cerebral hemodynamics, systemic hemodynamics, electrocardiography, and actigraphy during people's daily activities. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:47003. [PMID: 24781591 DOI: 10.1117/1.jbo.19.4.047003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 03/05/2014] [Indexed: 06/03/2023]
Abstract
The feasibility and utility of wearable 24-h multimodality neuromonitoring during daily activities are demonstrated. We have developed a fourth-generation ambulatory near infrared spectroscopy device, namely NINscan 4. NINscan 4 enables recording of brain function (via cerebral hemodynamics), systemic hemodynamics, electrocardiography, and actigraphy simultaneously and continuously for up to 24 h at 250-Hz sampling rate, during (and with minor restriction to) daily activities. We present initial 24-h human subject test results, with example analysis including (1) comparison of cerebral perfusion and oxygenation changes during wakefulness and sleep over a 24-h period and (2) capturing of hemodynamic changes prior, during and after sudden waken up in the night during sleep. These results demonstrate the first ambulatory 24-h cerebral and systemic hemodynamics monitoring, and its unique advantages including long-term data collection and analysis capability, ability to catch unpredictable transient events during activities of daily living, as well as coregistered multimodality analysis capabilities. These results also demonstrate that NINscan 4's motion artifact at 1-g head movement is smaller than physiological hemodynamic fluctuations during motionless sleep. The broader potential of this technology is also discussed.
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Affiliation(s)
- Quan Zhang
- Massachusetts General Hospital, Harvard Medical School Neural Systems Group, 13th Street, Building 149, Room 2651, Charlestown, Massachusetts 02129bCenter for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Vladimir Ivkovic
- Massachusetts General Hospital, Harvard Medical School Neural Systems Group, 13th Street, Building 149, Room 2651, Charlestown, Massachusetts 02129
| | - Gang Hu
- Massachusetts General Hospital, Harvard Medical School Neural Systems Group, 13th Street, Building 149, Room 2651, Charlestown, Massachusetts 02129
| | - Gary E Strangman
- Massachusetts General Hospital, Harvard Medical School Neural Systems Group, 13th Street, Building 149, Room 2651, Charlestown, Massachusetts 02129bCenter for Space Medicine, Baylor College of Medicine, Houston, Texas
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Metz AJ, Pugin F, Huber R, Achermann P, Wolf M. Brain Tissue Oxygen Saturation Increases During the Night in Adolescents. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 789:113-119. [DOI: 10.1007/978-1-4614-7411-1_16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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14
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Aritake S, Higuchi S, Suzuki H, Kuriyama K, Enomoto M, Soshi T, Kitamura S, Hida A, Mishima K. Increased cerebral blood flow in the right frontal lobe area during sleep precedes self-awakening in humans. BMC Neurosci 2012; 13:153. [PMID: 23256572 PMCID: PMC3538054 DOI: 10.1186/1471-2202-13-153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 12/11/2012] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Some people can subconsciously wake up naturally (self-awakening) at a desired/planned time without external time stimuli. However, the underlying mechanism regulating this ability remains to be elucidated. This study sought to examine the relationship between hemodynamic changes in oxyhemoglobin (oxy-Hb) level in the prefrontal cortex and sleep structures during sleep in subjects instructed to self-awaken. RESULTS Fifteen healthy right-handed male volunteers with regular sleep habits participated in a consecutive two-night crossover study. The subjects were instructed to wake up at a specified time ("request" condition) or instructed to sleep until the morning but forced to wake up at 03:00 without prior notice ("surprise" condition). Those who awoke within ± 30 min of the planned waking time were defined as those who succeeded in self-awakening ("success" group). Seven subjects succeeded in self-awakening and eight failed.No significant differences were observed in the amounts of sleep in each stage between conditions or between groups. On the "request" night, an increase in oxy-Hb level in the right prefrontal cortex and a decrease in δ power were observed in the "success" group around 30 min before self-awakening, whereas no such changes were observed in the "failure" group. On the "surprise" night, no significant changes were observed in oxy-Hb level or δ power in either group. CONCLUSIONS These findings demonstrate a correlation between self-awakening and a pre-awakening increase in hemodynamic activation in the right prefrontal cortex, suggesting the structure's contribution to time estimation ability.
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Affiliation(s)
- Sayaka Aritake
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
- Japan Society for the Promotion of Science, Tokyo, 102-8471, Japan
- Department of Somnology, Tokyo Medical University, Tokyo, 160-0023, Japan
- Department of Life Sciences and Bio-informatics, Graduate School of Allied Health Sciences, Tokyo Medical and Dental University, Tokyo, 113-0034, Japan
| | - Shigekazu Higuchi
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
- Department of Human Science, Faculty of Design, Kyushu University, Fukuoka, 815-8540, Japan
| | - Hiroyuki Suzuki
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Kenichi Kuriyama
- Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Minori Enomoto
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
- Department of Life Sciences and Bio-informatics, Graduate School of Allied Health Sciences, Tokyo Medical and Dental University, Tokyo, 113-0034, Japan
| | - Takahiro Soshi
- Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Shingo Kitamura
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Akiko Hida
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
| | - Kazuo Mishima
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, 187-8502, Japan
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Näsi T, Virtanen J, Noponen T, Toppila J, Salmi T, Ilmoniemi RJ. Spontaneous hemodynamic oscillations during human sleep and sleep stage transitions characterized with near-infrared spectroscopy. PLoS One 2011; 6:e25415. [PMID: 22043284 PMCID: PMC3197192 DOI: 10.1371/journal.pone.0025415] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Accepted: 09/02/2011] [Indexed: 11/18/2022] Open
Abstract
Understanding the interaction between the nervous system and cerebral vasculature is fundamental to forming a complete picture of the neurophysiology of sleep and its role in maintaining physiological homeostasis. However, the intrinsic hemodynamics of slow-wave sleep (SWS) are still poorly known. We carried out 30 all-night sleep measurements with combined near-infrared spectroscopy (NIRS) and polysomnography to investigate spontaneous hemodynamic behavior in SWS compared to light (LS) and rapid-eye-movement sleep (REM). In particular, we concentrated on slow oscillations (3-150 mHz) in oxy- and deoxyhemoglobin concentrations, heart rate, arterial oxygen saturation, and the pulsation amplitude of the photoplethysmographic signal. We also analyzed the behavior of these variables during sleep stage transitions. The results indicate that slow spontaneous cortical and systemic hemodynamic activity is reduced in SWS compared to LS, REM, and wakefulness. This behavior may be explained by neuronal synchronization observed in electrophysiological studies of SWS and a reduction in autonomic nervous system activity. Also, sleep stage transitions are asymmetric, so that the SWS-to-LS and LS-to-REM transitions, which are associated with an increase in the complexity of cortical electrophysiological activity, are characterized by more dramatic hemodynamic changes than the opposite transitions. Thus, it appears that while the onset of SWS and termination of REM occur only as gradual processes over time, the termination of SWS and onset of REM may be triggered more abruptly by a particular physiological event or condition. The results suggest that scalp hemodynamic changes should be considered alongside cortical hemodynamic changes in NIRS sleep studies to assess the interaction between the autonomic and central nervous systems.
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Affiliation(s)
- Tiina Näsi
- Department of Biomedical Engineering and Computational Science (BECS), Aalto University, Aalto, Espoo, Finland
- BioMag Laboratory, HUSLAB, Helsinki University Central Hospital, Helsinki, Finland
| | - Jaakko Virtanen
- Department of Biomedical Engineering and Computational Science (BECS), Aalto University, Aalto, Espoo, Finland
- BioMag Laboratory, HUSLAB, Helsinki University Central Hospital, Helsinki, Finland
| | - Tommi Noponen
- Department of Nuclear Medicine and Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Jussi Toppila
- Department of Clinical Neurophysiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Tapani Salmi
- Department of Clinical Neurophysiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Risto J. Ilmoniemi
- Department of Biomedical Engineering and Computational Science (BECS), Aalto University, Aalto, Espoo, Finland
- BioMag Laboratory, HUSLAB, Helsinki University Central Hospital, Helsinki, Finland
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17
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Kubota Y, Takasu NN, Horita S, Kondo M, Shimizu M, Okada T, Wakamura T, Toichi M. Dorsolateral prefrontal cortical oxygenation during REM sleep in humans. Brain Res 2011; 1389:83-92. [PMID: 21382356 DOI: 10.1016/j.brainres.2011.02.061] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 02/17/2011] [Accepted: 02/19/2011] [Indexed: 12/18/2022]
Abstract
Previous neuroimaging studies that examined cerebral blood flow during rapid eye movement (REM) sleep have reported inconsistent findings regarding the activity of the dorsolateral prefrontal cortex (DLPFC). Although most previous positron emission tomography (PET) studies failed to detect DLPFC activation during REM sleep, several studies have observed DLPFC activation, possibly reflecting transient prefrontal activities related to REM. More recently, an event-related functional magnetic resonance imaging (fMRI) study observed REM-locked activation of the DLPFC during REM sleep. The present study investigated hemodynamic changes of the DLPFC throughout the REM sleep period in 25 subjects using near-infrared spectroscopy. Continuous monitoring of changes in the hemoglobin (Hb) concentration and tissue oxygenation index (TOI, proportion of oxygenated-Hb to total-Hb) in the bilateral DLPFC was conducted every 0.5s, simultaneously with polysomnographic recordings. Eight of the 25 subjects showed REM sleep, and all indicated a clear increase in both the oxygenated-Hb concentration and TOI from baseline at the occurrence of first REM, relative to prior stage 2 sleep. The results indicate that the appearance of the first REM that occurred just after onset of the REM sleep closely coincides with the activation of the DLPFC, which could play a role in cognitive activities during REM sleep in humans.
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Affiliation(s)
- Yasutaka Kubota
- Health and Medical Services Center, Shiga University, Shiga, Japan.
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18
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Durduran T, Choe R, Baker WB, Yodh AG. Diffuse Optics for Tissue Monitoring and Tomography. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2010; 73:076701. [PMID: 26120204 PMCID: PMC4482362 DOI: 10.1088/0034-4885/73/7/076701] [Citation(s) in RCA: 555] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
This review describes the diffusion model for light transport in tissues and the medical applications of diffuse light. Diffuse optics is particularly useful for measurement of tissue hemodynamics, wherein quantitative assessment of oxy- and deoxy-hemoglobin concentrations and blood flow are desired. The theoretical basis for near-infrared or diffuse optical spectroscopy (NIRS or DOS, respectively) is developed, and the basic elements of diffuse optical tomography (DOT) are outlined. We also discuss diffuse correlation spectroscopy (DCS), a technique whereby temporal correlation functions of diffusing light are transported through tissue and are used to measure blood flow. Essential instrumentation is described, and representative brain and breast functional imaging and monitoring results illustrate the workings of these new tissue diagnostics.
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Affiliation(s)
- T Durduran
- ICFO- Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
| | - R Choe
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - W B Baker
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
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19
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Changes in cerebral hemoglobin indices in obstructive sleep apnea syndrome with nasal continuous positive airway pressure treatment. Sleep Breath 2010; 15:487-92. [DOI: 10.1007/s11325-010-0367-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 05/02/2010] [Accepted: 05/11/2010] [Indexed: 10/19/2022]
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20
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Virtanen J, Noponen T, Meriläinen P. Comparison of principal and independent component analysis in removing extracerebral interference from near-infrared spectroscopy signals. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:054032. [PMID: 19895134 DOI: 10.1117/1.3253323] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Near-infrared spectroscopy (NIRS) is a method for noninvasive estimation of cerebral hemodynamic changes. Principal component analysis (PCA) and independent component analysis (ICA) can be used for decomposing a set of signals to underlying components. Our objective is to determine whether PCA or ICA is more efficient in identifying and removing scalp blood flow interference from multichannel NIRS signals. Concentration changes of oxygenated (HbO(2)) and deoxygenated (HbR) hemoglobin are measured on the forehead with multichannel NIRS during hyper- and hypocapnia. PCA and ICA are used separately to identify and remove signal contribution from extracerebral tissue, and the resulting estimates of cerebral responses are compared to the expected cerebral responses. Both methods were able to reduce extracerebral contribution to the signals, but PCA typically performs equal to or better than ICA. The improvement in 3-cm signal quality achieved with both methods is comparable to increasing the source-detector separation from 3 to 5 cm. Especially PCA appears to be well suited for use in NIRS applications where the cerebral activation is diffuse, such as monitoring of global cerebral oxygenation and hemodynamics. Performance differences between PCA and ICA could be attributed primarily to different criteria for identifying the surface effect.
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Affiliation(s)
- Jaakko Virtanen
- Helsinki University of Technology, Department of Biomedical Engineering and Computational Science, P.O. Box 3310, FI-02015 TKK, Helsinki, Finland.
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21
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22
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23
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Intrinsic correlations of electroencephalography rhythms with cerebral hemodynamics during sleep transitions. Neuroimage 2008; 42:357-68. [PMID: 18514543 DOI: 10.1016/j.neuroimage.2008.03.055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 02/14/2008] [Accepted: 03/28/2008] [Indexed: 11/21/2022] Open
Abstract
To examine the correlation between electroencephalography fluctuations (EEGF) and cerebral hemodynamics during sleep after eliminating influences from cardiovascular activity, we simultaneously measured EEGF, the cerebral hemoglobin concentration change, and mean arterial blood pressure (MAP) during the sleep of healthy human adults. The cerebral hemoglobin concentration change was measured at 88 positions covering the whole head, by optical topography. We extracted the intrinsic correlation between EEGF and the cerebral hemoglobin concentration change without MAP contributions through cross-correlation and partial correlation analyses considering time lags. We found that increases in the power of the alpha rhythm in EEGF were correlated with increases in oxygenated hemoglobin (oxy-Hb) and decreases in deoxygenated hemoglobin (deoxy-Hb) and that increases in the power of the sigma rhythm in EEGF were correlated with decreases in oxy-Hb and increases in deoxy-Hb. The former correlations tended to appear in the transition from sleep stage 2 to sleep stage 1, and the latter correlations tended to appear in the transition from sleep stage 1 to sleep stage 2. The former correlations were found in the inferior frontal and middle temporal gyri and the latter correlations were found in the superior frontal, middle frontal, and angular gyri.
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24
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Culver JP, Siegel AM, Franceschini MA, Mandeville JB, Boas DA. Evidence that cerebral blood volume can provide brain activation maps with better spatial resolution than deoxygenated hemoglobin. Neuroimage 2005; 27:947-59. [PMID: 16084112 DOI: 10.1016/j.neuroimage.2005.05.052] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 03/18/2005] [Accepted: 05/07/2005] [Indexed: 10/25/2022] Open
Abstract
With the aim of evaluating the relative performance of hemodynamic contrasts for mapping brain activity, the spatio-temporal response of oxy-, deoxy-, and total-hemoglobin concentrations were imaged with diffuse optical tomography during electrical stimulation of the rat somatosensory cortex. For both 6-s and 30-s stimulus durations, total hemoglobin images provided smaller activation areas than oxy- or deoxy-hemoglobin images. In addition, analysis of regions of interest near the sagittal sinus vein show significantly greater contrast in both oxy- and deoxy-relative to total hemoglobin, suggesting that oximetric contrasts have larger draining vein contributions compared to total hemoglobin contrasts under the given stimulus conditions. These results indicate that total hemoglobin and cerebral blood volume may have advantages as hemodynamic mapping contrasts, particularly for large amplitude, longer duration stimulus paradigms.
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Affiliation(s)
- Joseph P Culver
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, MO 63110, USA.
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25
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De Gennaro L, Bertini M, Ferrara M, Curcio G, Cristiani R, Romei V, Fratello F, Pauri F, Rossini PM. Intracortical inhibition and facilitation upon awakening from different sleep stages: a transcranial magnetic stimulation study. Eur J Neurosci 2004; 19:3099-104. [PMID: 15182318 DOI: 10.1111/j.0953-816x.2004.03411.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Intracortical facilitation and inhibition, as assessed by the paired-pulse transcranial magnetic stimulation technique with a subthreshold conditioning pulse followed by a suprathreshold test pulse, was studied upon awakening from REM and slow-wave sleep (SWS). Ten normal subjects were studied for four consecutive nights. Intracortical facilitation and inhibition were assessed upon awakening from SWS and REM sleep, and during a presleep baseline. Independently of sleep stage at awakening, intracortical inhibition was found at 1-3-ms interstimulus intervals and facilitation at 7-15-ms interstimulus intervals. Motor thresholds were higher in SWS awakenings, with no differences between REM awakenings and wakefulness, while motor evoked potential amplitude to unconditioned stimuli decreased upon REM awakening as compared to the other conditions. REM sleep awakenings showed a significant increase of intracortical facilitation at 10 and 15 ms, while intracortical inhibition was not affected by sleep stage at awakening. While the dissociation between motor thresholds and motor evoked potential amplitudes could be explained by the different excitability of the corticospinal system during SWS and REM sleep, the heightened cortical facilitation upon awakening from REM sleep points to a cortical motor activation during this stage.
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Affiliation(s)
- Luigi De Gennaro
- Dipartimento di Psicologia, Università di Roma La Sapienza, Via dei Marsi 78, 00185 Rome, Italy.
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26
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Urbas A, Manning MW, Daugherty A, Cassis LA, Lodder RA. Near-Infrared Spectrometry of Abdominal Aortic Aneurysm in the ApoE-/- Mouse. Anal Chem 2003; 75:3650-5. [PMID: 14570222 DOI: 10.1021/ac034113n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Abdominal aortic aneurysms (AAAs) occur in 5-7% of people over age 60 in the United States. Early intervention in the disease process could have a significant impact on the incidence of complications and on patient survival, but identifying incipient aneurysms can be difficult. ApoE knockout mice develop AAAs following infusion of angiotensin II (AngII) by osmotic minipump into the subcutaneous space of mice at doses ranging from 500 to 1000 ng kg(-1) min(-1) for 7-28 days. These mice are used as models of AAA development. This study tested the hypothesis that near-IR spectrometry and PCR can determine AngII dose (SEE = 26 ng kg(-1) min(-1), SEP = 37 ng kg(-1) min(-1), r2 = 0.99) and collagen/elastin (C/E) ratio (SEE = 0.38, SEP = 0.39, r2 = 0.85) in mouse aortas.
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Affiliation(s)
- Aaron Urbas
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
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27
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Moreno PR, Muller JE. Detection of high-risk atherosclerotic coronary plaques by intravascular spectroscopy. J Interv Cardiol 2003; 16:243-52. [PMID: 12800403 DOI: 10.1034/j.1600-0854.2003.8040.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Multiple technologies are under development to identify plaque composition and vulnerability. This review article is intended to provide basic knowledge to the interventional cardiologist and the clinician about spectroscopy. The concept of light, the wavelength unit and the electromagnetic spectrum are discussed. Different types of spectra analysis including nuclear magnetic resonance, Raman, fluorescence and diffuse reflectance near-infrared spectroscopy are then carefully reviewed. Experimental data to identify atherosclerotic plaque composition for each of these techniques is provided. Potential benefits and challenges are addressed. Finally, diffuse reflectance near-infrared spectroscopy is discussed in more detail as a promising technique to characterize plaque vulnerability in humans.
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Affiliation(s)
- Pedro R Moreno
- Linda and Jack Gill Heart Institute, University of Kentucky, Lexington, KY, USA.
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28
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Zoccoli G, Walker AM, Lenzi P, Franzini C. The cerebral circulation during sleep: regulation mechanisms and functional implications. Sleep Med Rev 2002; 6:443-55. [PMID: 12505477 DOI: 10.1053/smrv.2001.0194] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cerebral blood flow measurements during sleep are reviewed and discussed in relation to the different techniques utilized (Positron Emission Tomography, functional Magnetic Resonance Imaging, Flowmeters, Radioactive MicroIspheres, Brain Temperature Recordings, Spectrophotometry) since these methodological approaches aim at diverse features of circulation changes in the spatial or temporal domain. The regulation of cerebral circulation during sleep reveals no specific state-dependent features, flow-activity coupling being the prevailing mechanism, with O(2) as the primary candidate for the metabolic side of the link. On a general level, the latest data on brain circulation are compatible with the classical hypothesis of a "restorative" function of sleep processes.
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Affiliation(s)
- Giovanna Zoccoli
- Department of Human and General Physiology, University of Bologna, Piazza di Porta S. Donato, Italy
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29
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Affiliation(s)
- Pedro R Moreno
- The Linda and Jack Gill Heart Institute, University of Kentucky, 111B-CDD 1101 Veterans Drive, Lexington, KY 40502, USA.
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30
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Moreno PR, Lodder RA, Purushothaman KR, Charash WE, O'Connor WN, Muller JE. Detection of lipid pool, thin fibrous cap, and inflammatory cells in human aortic atherosclerotic plaques by near-infrared spectroscopy. Circulation 2002; 105:923-7. [PMID: 11864919 DOI: 10.1161/hc0802.104291] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND A method is needed to identify nonstenotic, lipid-rich coronary plaques that are likely to cause acute coronary events. Near-infrared (NIR) spectroscopy can provide information on the chemical composition of tissue. We tested the hypothesis that NIR spectroscopy can identify plaque composition and features associated with plaque vulnerability in human aortic atherosclerotic plaques obtained at the time of autopsy. METHODS AND RESULTS A total of 199 samples from 5 human aortic specimens were analyzed by NIR spectroscopy. Features of plaque vulnerability were defined by histology as presence of lipid pool, thin fibrous cap (<65 microm by ocular micrometry), and inflammatory cell infiltration. An InfraAlyzer 500 spectrophotometer was used. Spectral absorbance values were obtained as log (1/R) data from 1100 to 2200 nm at 10-nm intervals. Principal component regression was used for analysis. An algorithm was constructed with 50% of the samples used as a reference set; blinded predictions of plaque composition were then performed on the remaining samples. NIR spectroscopy sensitivity and specificity for histological features of plaque vulnerability were 90% and 93% for lipid pool, 77% and 93% for thin cap, and 84% and 89% for inflammatory cells, respectively. CONCLUSIONS NIR spectroscopy can identify plaque composition and features associated with plaque vulnerability in postmortem human aortic specimens. These results support efforts to develop an NIR spectroscopy catheter system to detect vulnerable coronary plaques in living patients.
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Affiliation(s)
- Pedro R Moreno
- Linda and Jack Gill Heart Institute, University of Kentucky, Lexington, USA.
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31
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De Gennaro L, Ferrara M, Bertini M. The boundary between wakefulness and sleep: quantitative electroencephalographic changes during the sleep onset period. Neuroscience 2002; 107:1-11. [PMID: 11744241 DOI: 10.1016/s0306-4522(01)00309-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Microstructural electroencephalographic changes during the wakefulness-sleep transition have been investigated by comparing two definitions of sleep onset: the first occurrence of stage 1 and of stage 2. Power values were calculated across a 1-28-Hz frequency range in a 1-Hz bin resolution in the sleep recordings of 26 normal subjects. Quantitative changes were assessed after averaging individual time series, aligned with respect to the first occurrence of stage 1 or of stage 2. The time course of the single-Hz activity revealed a linear increase of power in the 1-6-Hz range and a linear decrease in the 9-12- and 16-28-Hz ranges during the stage 1 transition. During the stage 2 transition, electroencephalogram power linearly increased in the 1-7- and 14-15-Hz ranges and decreased in the 18-28-Hz range, while the 8-12-Hz range fitted a second-order polynomial curve. The two 'switch' points were also compared in their ability to differentiate Hz by Hz wakefulness from sleep: a lower mean power was found after stage 1 onset in the 9-11-Hz and 20-28-Hz bins and a higher one in the 1-5-Hz bins, while a higher power was found in the 1-8-Hz and 12-16-Hz bins and a lower one in 18-28-Hz bins after stage 2 onset. The time course of three electroencephalographic frequency ranges [delta/theta/sigma (1-7 and 12-16 Hz); beta (17-28 Hz); alpha (8-11 Hz)], grouped on the basis of a principal component analysis, fitted a first-order polynomial curve for the first two ranges, and a second-order polynomial curve for the last, with a progressive decrease during wakefulness, a minimum point during stage 1, and a subsequent increase during stage 2. The uniformly increasing electroencephalographic power across the 1-16-Hz frequency range during stage 2 and the shift of functional meaning for the alpha power during stage 1 point to the start of stage 2 as a more reliable boundary between wakefulness and sleep.
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Affiliation(s)
- L De Gennaro
- Department of Psychology, Section of Neuroscience, University of Rome La Sapienza, Via dei Marsi 78, 00185, Rome, Italy.
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32
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De Gennaro L, Ferrara M, Curcio G, Cristiani R. Antero-posterior EEG changes during the wakefulness-sleep transition. Clin Neurophysiol 2001; 112:1901-11. [PMID: 11595150 DOI: 10.1016/s1388-2457(01)00649-6] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVES To investigate the brain topography of the human sleep EEG along the antero-posterior axis during the wakefulness-sleep transition, by means of both a single Hz analysis and a grouped-frequency analysis of EEG changes. METHODS EEG power values were calculated across a 1-28 Hz frequency range in a 1 Hz resolution during the wakefulness-sleep transition of 7 normal subjects. Topographical changes were assessed from C3-A2, C4-A1, Fpz-A1, Fz-A1, Cz-A1, Pz-A1, Oz-A1 recordings, after averaging individual time series, aligned with respect to the onset of stage 2. RESULTS The single Hz analysis showed that before sleep onset (SO), the <7 Hz slow frequencies were more prominent at the more anterior scalp locations; this anterior prominence was counterbalanced by a reciprocal prevalence across the >8 Hz frequencies of EEG activity from the occipital areas; while the >13 Hz fast frequencies were not characterized by significant antero-posterior differences. After SO, more EEG power was found in the range of slow frequencies at the centro-frontal scalp locations and a second peak of EEG activity was also revealed within the range of the sigma frequency, higher at the centro-parietal scalp locations. No consistent topographical changes were observed within the range of faster EEG frequencies. Grouped-frequency analysis confirmed these results, also pointing to different changes in the alpha frequency as a function of the SO point. CONCLUSIONS The results suggest that: (a) the alpha rhythm spreads anteriorly as the transition progresses; (b) several anterior areas first synchronize EEG activity; (c) the functional meaning of the EEG bands during the SO period should be partially revised with regard at least to alpha rhythm; (d) SO coincides with the start of stage 2.
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Affiliation(s)
- L De Gennaro
- Dipartimento di Psicologia, Sezione di Neuoroscienze, Università degli Studi di Roma La Sapienza, Via dei Marsi, 78, 00185, Rome, Italy.
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