Optimization of the Coherence Measurement Computed by Means of the Welch Averaged Periodogram Method for Assessment of Impaired Cerebral Autoregulation

  • D. De Smet
  • J. Vanderhaegen
  • G. Naulaers
  • S. Van Huffel
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 662)


The coherence method (COH) has been widely used to study the concordance between continuously measured signals intervening in the assessment of cerebral autoregulation in neonates. Several research groups have applied this method to mean arterial blood pressure (MABP) combined with cerebral signals such as the intravascular oxygenation (HbD), cerebral tissue oxygenation (TOI), and regional oxygen saturation (rSO2) measured by near-infrared spectroscopy (NIRS). All groups contributed in a particular way to the fine-tuning of the application of COH with the Welch averaged periodogram (WAP) method. We have made a comparative study of all published results coupled with an optimization of the use of the WAP method within COH. We have also proposed a pre-processing algorithm to remove signal artefacts, and defined a new critical score value (CSV) for COH to distinguish infants with impaired autoregulation from those without.


Fast Fourier Transform Mean Arterial Blood Pressure Cerebral Oxygenation Hanning Window Signal Periodicity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The research was supported by: Research Council KUL: GOA AMBioRICS, CoE EF/05/006, by FWO projects G.0519.06 (Non-invasive brain oxygenation), and G.0341.07 (Data fusion), by Belgian Federal Science Policy Office IUAP P5/22. We thank particularly Prof. Frank van Bel and Dr. Petra Lemmers from the University Medical Centre Utrecht (The Netherlands), and PD Dr. Martin Wolf from the University Hospital Zurich (Switzerland) for having let us use their signal recordings.


  1. 1.
    Tsuji M, Saul J, du Plessis A et al. (2000) Cerebral intravascular oxygenation correlates with mean arterial pressure in critically ill premature infants. Pediatr Rev 106(4):625–632.Google Scholar
  2. 2.
    Morren G, Lemmerling P, Van Huffel S et al. (2001) Detection of autoregulation in the brain of premature infants using a novel subspace-based technique. Proc of 23rd Intern IEEE-EMBS Conf 2:2064–2067.Google Scholar
  3. 3.
    Soul J, Hammer P, Tsuji M et al. (2007) Fluctuating pressure-passivity is common in the cerebral circulation of sick premature infants. Pediatr Res 61(4):467–473.PubMedCrossRefGoogle Scholar
  4. 4.
    Taylor J, Carr D, Myers C et al. (1998) Humans mechanisms underlying very-low-frequency RR-interval oscillations in humans. Circulation 98:547–555.PubMedGoogle Scholar
  5. 5.
    Urlesberger B, Trip K, Ruchti J et al. (1998) Quantification of cyclical fluctuations in cerebral blood volume in healthy infants. Neuropediatrics 29(4):208–211.PubMedCrossRefGoogle Scholar
  6. 6.
    von Siebenthal K, Beran J, Wolf M et al. (1999) Cyclical fluctuations in blood pressure, heart rate and cerebral blood volume in preterm infants. Brain & Dev 21:529–534.CrossRefGoogle Scholar
  7. 7.
    Carter D, Knapp C, Nuttall A (1973) Estimation of the magnitude-squared coherence function via overlapped fast Fourier transform processing. IEEE Trans Audio Electroacoust 21(4):337–344.CrossRefGoogle Scholar
  8. 8.
    Wong F, Leung T, Austin T et al. (2008) Impaired autoregulation in preterm infants identified by using spatially resolved spectroscopy. Pediatrics 121:604–611.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • D. De Smet
    • 1
  • J. Vanderhaegen
    • 2
  • G. Naulaers
    • 2
  • S. Van Huffel
    • 1
  1. 1.Department of Electrical Engineering (ESAT), SCD DivisionKatholieke Universiteit LeuvenLeuvenBelgium
  2. 2.Department of NeonatologyUniversity Hospital Gasthuisberg, Katholieke Universiteit LeuvenLeuvenBelgium

Personalised recommendations