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Computational and Mathematical Methods in Medicine
Volume 2013 (2013), Article ID 645702, 8 pages
http://dx.doi.org/10.1155/2013/645702
Research Article

Novel Application of a Multiscale Entropy Index as a Sensitive Tool for Detecting Subtle Vascular Abnormalities in the Aged and Diabetic

1Department of Electrical Engineering, National Dong Hwa University, Hualien, No. 1, Section 2, Da-Hsueh Road, Shoufeng, Hualien 97401, Taiwan
2Research Center for Adaptive Data Analysis and Center for Dynamical Biomarkers and Translational Medicine, National Central University, Chungli, Taiwan
3Department of Emergency Medicine, E-Da Hospital, I-Shou University, Kaohsiung City, Taiwan
4Department of Chinese Medicine, Buddhist Tzu-Chi General Hospital Taichung Branch, Taichung, Taiwan
5School of Chinese Medicine, Tzu Chi University, Hualien, Taiwan

Received 5 November 2012; Accepted 28 December 2012

Academic Editor: Guang Hu

Copyright © 2013 Hsien-Tsai Wu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Although previous studies have shown the successful use of pressure-induced reactive hyperemia as a tool for the assessment of endothelial function, its sensitivity remains questionable. This study aims to investigate the feasibility and sensitivity of a novel multiscale entropy index (MEI) in detecting subtle vascular abnormalities in healthy and diabetic subjects. Basic anthropometric and hemodynamic parameters, serum lipid profiles, and glycosylated hemoglobin levels were recorded. Arterial pulse wave signals were acquired from the wrist with an air pressure sensing system (APSS), followed by MEI and dilatation index (DI) analyses. MEI succeeded in detecting significant differences among the four groups of subjects: healthy young individuals, healthy middle-aged or elderly individuals, well-controlled diabetic individuals, and poorly controlled diabetic individuals. A reduction in multiscale entropy reflected age- and diabetes-related vascular changes and may serve as a more sensitive indicator of subtle vascular abnormalities compared with DI in the setting of diabetes.