University of Oulu

Ferdinando, H., Moradi, S., Korhonen, V. et al. Spectral entropy provides separation between Alzheimer’s disease patients and controls: a study of fNIRS. Eur. Phys. J. Spec. Top. 232, 655–662 (2023).

Spectral entropy provides separation between Alzheimer’s disease patients and controls : a study of fNIRS

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Author: Ferdinando, H.1,2; Moradi, S.3; Korhonen, V.4,5;
Organizations: 1Research Unit of Health Sciences and Technology, University of Oulu, 90100 Oulu, Finland
2Department of Electrical Engineering, Petra Christian University, Surabaya 60236, Indonesia
3Opto-Electronics and Measurement Technique Research Unit, University of Oulu, 90570, Oulu, Finland
4Research Unit of Health Sciences and Technology, University of Oulu, 90100, Oulu, Finland
5Department of Radiology, Oulu University Hospital, 90100, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.3 MB)
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Language: English
Published: Springer Nature, 2023
Publish Date: 2023-06-12


Functional near-infrared spectroscopy (fNIRS) is commonly used as a non-invasive tool to measure cerebral neurovascular dynamics. Its potential for diagnostics of various brain disorders has been already demonstrated in many recent studies, including Alzheimer’s disease (AD). fNIRS studies are usually based on comparing hemoglobin measurements at baseline and during a specific task. At present, many proposed methods using fNIRS to diagnose AD involve certain tasks, which may be challenging for the elderly and patients with cognitive decline. Here, we propose a method to characterize AD patients and control in resting state, by applying spectral entropy (SE) analysis on oxyhemoglobin and deoxyhemoglobin, HbO and HbR, respectively, and total hemoglobin (HbT) based on fNIRS signals measured from the left and right sides of the forehead. We applied SE to very low frequency (VLF) (0.008–0.1 Hz), respiratory (0.1–0.6 Hz), and cardiac (0.6–5 Hz) bands to find out which band delivered the optimum result. Next, a t test with 0.05 significant level was performed to compare SE values of AD patients and controls. Results from the VLF band looked promising as SE values from AD patients were always significantly higher than those from controls. In addition, this phenomenon was consistent for both sides of the forehead. However, significant differences in SE values in the respiratory band were found from the left hemisphere only, and in the cardiac band from the right hemisphere only. SE value from the VLF band supports a strong argument that it provides good predictability related to the development of AD. We demonstrated that SE of brain fNIRS signal can be an useful biomarker for Alzheimer’s disease pathology.

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Series: The European physical journal. Special topics
ISSN: 1951-6355
ISSN-E: 1951-6401
ISSN-L: 1951-6355
Volume: 232
Pages: 655 - 662
DOI: 10.1140/epjs/s11734-022-00753-w
Type of Publication: A1 Journal article – refereed
Field of Science: 3112 Neurosciences
217 Medical engineering
Funding: The authors would like to acknowledge Academy of Finland, Grant/Award numbers: 318347, 338599, TERVA 314497, TERVA 335720; Jane ja Aatos Erkko Foundation; Riitta and Jorma J. Takanen foundation; Business Finland Grant (42539/31/2020) and Infotech for financing this research.
Academy of Finland Grant Number: 318347
Detailed Information: 318347 (Academy of Finland Funding decision)
338599 (Academy of Finland Funding decision)
314497 (Academy of Finland Funding decision)
335720 (Academy of Finland Funding decision)
Dataset Reference: Data cannot be made available for public because we do not have permission to share raw data.
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