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Investigation of blood pulse PPG signal regulation on toe effect of body posture and lower limb height

journal contribution
posted on 2016-08-05, 14:14 authored by Shang-Zhi Xin, Sijung HuSijung Hu, Vincent P. Crabtree, Jia Zheng, V Azorin-Peris, Angelos S. Echiadis, Peter R. Smith
Objective. To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods. Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results. In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion. The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.


The authors sincerely acknowledge the kind help of University of Shanghai for Science and Technology in sponsoring the academic visitors to the UK.



  • Mechanical, Electrical and Manufacturing Engineering

Published in

Journal of Zhejiang University SCIENCE A






. 916 - 920


XIN, S. ... et al., 2007. Investigation of blood pulse PPG signal regulation on toe effect of body posture and lower limb height. Journal of Zhejiang University, Science A, 8 (6), pp.916-920.


© Springer


  • VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date



The final publication is available at Springer via: http://dx.doi.org/10.1631/jzus.2007.A0916.