Decoupling the influence of systemic variables in the peripheral and cerebral haemodynamics during ECMO procedure by means of oblique and orthogonal subspace projections

Caicedo, Alexander; Tachtsidis, Ilias; Papademetriou, Maria D.; Huffel, Sabine Van

doi:10.1109/embc.2012.6347398

Cited by 7 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the power of the respiratory-related component of HR (or BP) signal could be calculated and serves as an index of respiratory influence on HR (or BP). Accordingly, the first step of the algorithm is to construct the respiratory subspace (V), which was formed by wavelet coefficients and their delayed versions of respiratory signal (Caicedo et al, 2012; Widjaja et al, 2014). The level of the wavelet decomposition was 5 and the delay was set at 3 s in this study.…”

Section: Methodsmentioning

confidence: 99%

Increased Respiratory Modulation of Blood Pressure in Hypertensive Patients

Xie

Zhao

et al. 2019

Front. Physiol.

View full text Add to dashboard Cite

Objective Although the important role of respiratory modulation of the cardiovascular system in the development of hypertension has been demonstrated in animal studies, little research has assessed this modulation in essential hypertensive patients. We aimed to explore whether respiratory-related variations in cardiovascular variables are changed in hypertensive patients and their potential relationships with the respiratory pattern. Methods Respiration, ECG, and beat-to-beat blood pressure (BP) were simultaneously measured in 46 participants (24 hypertensive patients and 22 normotensive participants) during rest and a mental arithmetic task (MAT). Respiratory-triggered averaging and orthogonal subspace projection methods were used to assess the respiratory modulations of BP and heart rate (HR). Respiratory parameters including inspiratory time, expiratory time, respiratory rate and their variabilities were also characterized. Results The inspiratory time, expiratory time, respiratory rate and their variabilities were not different between hypertensive and normotensives. Additionally, the modulation of HR by respiration was also similar between the two groups. Hypertensive patients exhibited an amplified respiratory modulation of systolic BP (SBP), as assessed from the amplitude of respiratory-related changes and the percentage of the power of respiratory-related variation, and also reflected from the temporal pattern of respiratory modulation of SBP. The exaggerated respiratory-related variation of SBP in hypertensive patients accounted for ≈23% of the total power of SBP, producing an absolute change of ≈4.5 mmHg in SBP. MAT was characterized by decreased inspiratory time and increased variabilities of expiratory time and respiratory rate with no changes in the amplitude of respiratory modulations. Conclusion Hypertensive patients had excessive respiratory modulation of SBP, despite having similar respiratory pattern with normotensives. These findings highlight the importance of respiratory influence in BP variation and suggest that respiratory modulation of SBP may have prognostic information for cardiovascular events in hypertensive patients.

show abstract

Section: Methodsmentioning

confidence: 99%

Increased Respiratory Modulation of Blood Pressure in Hypertensive Patients

Xie

Zhao

et al. 2019

Front. Physiol.

View full text Add to dashboard Cite

show abstract

“…Orthogonal subspace projection decomposes a signal in two independent components using a given reference, in this case the respiratory signal [8], [9].…”

Section: Orthogonal Subspace Projectionmentioning

confidence: 99%

Stress classification by separation of respiratory modulations in heart rate variability using orthogonal subspace projection

Widjaja

Vlemincx

Huffel

2013

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

View full text Add to dashboard Cite

Abstract-The influence of respiration on the heart rate is a phenomenon known as respiratory sinus arrhythmia. However, effects of respiration are often ignored in studies of heart rate variability. In this paper, we take respiratory influences into account by separating the tachogram in two components, one related to respiration and one residual component, using orthogonal subspace projection. We demonstrate that it is important to remove respiratory influences during classification of rest and mental stress. Using merely the original tachogram, the classification accuracy is 57.13%, while the use of the residual tachogram results in an almost perfect classification (accuracy = 97.88%).

show abstract

“…In a previous study we presented an algorithm, based on the use of orthogonal and oblique subspace projection techniques (OrSP), to decompose a target signal in a set of signals related to a given basis. In this study we exploit the use of this algorithm as a preprocessing step for CA assessment [9].…”

Section: Introductionmentioning

confidence: 99%

Preprocessing by means of subspace projections for continuous Cerebral Autoregulation assessment using NIRS

Caicedo

Naulaers²,

Huffel

2013

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

Self Cite

View full text Add to dashboard Cite

Abstract-Cerebral Autoregulation (CA) refers to the capability of the brain to maintain a more or less stable cerebral blood flow (CBF), despite the changes in blood perfusion. Monitoring this mechanism is of vital importance, especially in neonates, in order to prevent damage due to ischemia or hemorrhage. In clinical practice near-infrared spectroscopy (NIRS) measurements are used as a surrogate measurement for CBF. However, NIRS signals are highly dependent on the variations in arterial oxygen saturation (SaO 2 ). Therefore, only segments with relatively constant SaO 2 are used for CA assessment; which limits the possibilities of the use of NIRS for online monitoring. In this paper we propose the use of subspace projections to subtract the influence of SaO 2 from NIRS measurements. Since this approach will be used in an online monitoring system, this preprocessing is carried out in a window-by-window framework. However, the use of subspace projections in consecutive segments produces discontinuities; we propose a methodology to reduce these effects. Obtained results indicate that the proposed method reduces the effect of discontinuities between consecutive segments. In addition, this methodology is able to subtract the influence of SaO 2 from NIRS measurements. This approach facilitates the introduction of NIRS for online CA assessment.

show abstract

Decoupling the influence of systemic variables in the peripheral and cerebral haemodynamics during ECMO procedure by means of oblique and orthogonal subspace projections

Cited by 7 publications

References 7 publications

Increased Respiratory Modulation of Blood Pressure in Hypertensive Patients

Increased Respiratory Modulation of Blood Pressure in Hypertensive Patients

Stress classification by separation of respiratory modulations in heart rate variability using orthogonal subspace projection

Preprocessing by means of subspace projections for continuous Cerebral Autoregulation assessment using NIRS

Contact Info

Product

Resources

About