Investigation of cerebral haemodynamics by near-infrared spectroscopy in young healthy volunteers reveals posture-dependent spontaneous oscillations

Tachtsidis, Ilias; Elwell, Clare E.; Leung, Terence S.; Lee, Chuen-Wai; Smith, Martin; Delpy, David T.

doi:10.1088/0967-3334/25/2/003

Cited by 103 publications

(113 citation statements)

References 26 publications

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“…The behavior of oscillations at this frequency has been widely investigated [15,16], particularly in the context of vasomotion, whereby spontaneous oscillations in vascular tone are observed [17]. Payne et al [6], also showed that this is frequency at which the magnitude of the ABP-O2Hb transfer function is greatest, thus most likely providing the largest signal and highest robustness to noise, and it is the frequency component investigated in the study by [18], which provides, to the best of our knowledge, the only other previous measure of the phase angles between ABP and O2Hb/HHb in the literature.…”

Section: Discussionmentioning

confidence: 99%

Effects of arterial blood gas levels on cerebral blood flow and oxygen transport

Payne¹,

Mohammad²,

Tisdall³

et al. 2011

Biomed. Opt. Express

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Abstract. Near Infra-Red Spectroscopy (NIRS) is a non-invasive technique which can be used to investigate cerebral haemodynamics and oxygenation with high temporal resolution. When combined with measures of Cerebral Blood Flow (CBF), it has the potential to provide information about oxygen delivery, utilization and metabolism. However, the interpretation of experimental results is complex. Measured NIRS signals reflect both scalp and cerebral haemodynamics and are influenced by many factors. The relationship between Arterial Blood Pressure (ABP) and CBF has been widely investigated and it central to cerebral autoregulation. Changes in arterial blood gas levels have a significant effect on ABP and CBF and these relationships have been quantified previously. The relationship between ABP and NIRS signals, however, has not been fully characterized. In this paper, we thus investigate the influence of changes in arterial blood gas levels both experimentally and theoretically, using an extended mathematical model of cerebral blood flow and metabolism, in terms of the phase angle at 0.1 Hz. The autoregulation response is found to be strongly dependent upon the carbon dioxide (CO2) partial pressure but much less so upon changes in arterial oxygen saturation (SaO2). The results for phase angle sensitivity to CO2 show good agreement between experimental and theory, but a poorer agreement is found for the sensitivity to SaO2.

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Section: Discussionmentioning

confidence: 99%

Effects of arterial blood gas levels on cerebral blood flow and oxygen transport

Payne¹,

Mohammad²,

Tisdall³

et al. 2011

Biomed. Opt. Express

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“…amplitude, frequency, phase) can be modulated by the stimulus/task to some degree. For example, it was shown that the amplitude of LF and VLF oscillations depend on the activity state (rest vs. task) (Obrig et al, 2000a), sleep stage (Näsi et al, 2011), body posture (Tachtsidis et al, 2003(Tachtsidis et al, , 2004, or age of the subject (Peng et al, 2008;Safonova et al, 2004). Thus, although these oscillations arise spontaneously, their stimulus/task-evoked modulation capability leads to the conclusion that they may also be part of the systemic activity type 1 and type 2 (SC2-3).…”

Section: Classification Of Signal Componentsmentioning

confidence: 99%

A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology

Scholkmann¹,

Kleiser²,

Metz³

et al. 2014

NeuroImage

1,481

1,394

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This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy-and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy-and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. Contents

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“…The mechanical mounting system is connected to a seat with an adjustable back incline. The seat provides comfort and also the option of keeping the subject in a supine position during studies which can help reduce certain physiological noise effects such as the Mayer wave [10]. The original headrest of the seat was replaced by a mechanical framework to cradle the head and also to support and position the optodes as shown in figure 7.…”

Section: Resultsmentioning

confidence: 99%

A mechanical mounting system for functional near-infrared spectroscopy brain imaging studies

Coyle¹,

Markham²,

Lanigan³

et al. 2005

SPIE Proceedings

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In this work a mechanical optode mounting system for functional brain imaging with light is presented. The particular application here is a non-invasive optical brain computer interface (BCI) working in the near-infrared range. A BCI is a device that allows a user to interact with their environment through thought processes alone. Their most common use is as a communication aid for the severely disabled. We have recently pioneered the use of optical techniques for such BCI systems rather than the usual electrical modality [1]. Our optical BCI detects characteristic changes in the cerebral haemodynamic responses that occur during motor imagery tasks. On detection of features of the optical response, resulting from localised haemodynamic changes, the BCI translates such responses and provides visual feedback to the user. While signal processing has a large part to play in terms of optimising performance we have found that it is the mechanical mounting of the optical sources and detectors (optodes) that has the greatest bearing on the performance of the system and indeed presents many interesting and novel challenges with regard to sensor placement, depth of penetration, signal intensity, artifact reduction and robustness of measurement. Here a solution is presented that accommodates the range of experimental parameters required for the application as well as meeting many of the challenges outlined above. This is the first time that a concerted study on optode mounting systems for optical BCIs has been attempted and it is hoped this paper may stimulate further research in this area.

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Investigation of cerebral haemodynamics by near-infrared spectroscopy in young healthy volunteers reveals posture-dependent spontaneous oscillations

Cited by 103 publications

References 26 publications

Effects of arterial blood gas levels on cerebral blood flow and oxygen transport

Effects of arterial blood gas levels on cerebral blood flow and oxygen transport

A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology

A mechanical mounting system for functional near-infrared spectroscopy brain imaging studies

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