Robust Estimation of HDR in fMRI using H-infinity Filters

Sadasivan Puthusserypady, R. Jue, T. Ratnarajah

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Estimation and detection of the hemodynamic response (HDR) are of great importance in functional MRI (fMRI) data analysis. In this paper, we propose the use of three H-infinity adaptive filters (finite memory, exponentially weighted, and timevarying) for accurate estimation and detection of the HDR. The H8 approach is used because it safeguards against the worst case disturbances and makes no assumptions on the (statistical) nature of the signals [B. Hassibi and T. Kailath, in Proc. ICASSP, 1995, vol. 2, pp. 949-952; T. Ratnarajah and S. Puthusserypady, in Proc. 8th IEEEWorkshopDSP, 1998, pp. 1483-1487]. Performances of the proposed techniques are compared to the conventional t-test method as well as the well-known LMSs and recursive least squares algorithms. Extensive numerical simulations show that the proposed methods result in better HDR estimations and activation detections.
Original languageEnglish
JournalI E E E Transactions on Biomedical Engineering
Volume57
Issue number5
Pages (from-to)1133-1142
ISSN0018-9294
DOIs
Publication statusPublished - 2010

Keywords

  • functional MRI (fMRI)
  • Activation detection
  • hemodynamic response (HDR)
  • H-infinity filters

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