Table of Contents Author Guidelines Submit a Manuscript
Journal of Sensors
Volume 2017, Article ID 8916596, 10 pages
https://doi.org/10.1155/2017/8916596
Research Article

Influence on Calculated Blood Pressure of Measurement Posture for the Development of Wearable Vital Sign Sensors

1Institute for Fiber Engineering, Shinshu University, 3-15-1 Tokida, Ueda, Nagano, Japan
2Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano, Japan

Correspondence should be addressed to Shouhei Koyama; pj.ca.u-uhsnihs@iehuohs

Received 5 January 2017; Accepted 19 June 2017; Published 24 July 2017

Academic Editor: Christos Riziotis

Copyright © 2017 Shouhei Koyama 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

We studied a wearable blood pressure sensor using a fiber Bragg grating (FBG) sensor, which is a highly accurate strain sensor. This sensor is installed at the pulsation point of the human body to measure the pulse wave signal. A calibration curve is built that calculates the blood pressure by multivariate analysis using the pulse wave signal and a reference blood pressure measurement. However, if the measurement height of the FBG sensor is different from the reference measurement height, an error is included in the reference blood pressure. We verified the accuracy of the blood pressure calculation with respect to the measurement height difference and the posture of the subject. As the difference between the measurement height of the FBG sensor and the reference blood pressure measurement increased, the accuracy of the blood pressure calculation decreased. When the measurement height was identical and only posture was changed, good accuracy was achieved. In addition, when calibration curves were built using data measured in multiple postures, the blood pressure of each posture could be calculated from a single calibration curve. This will allow miniaturization of the necessary electronics of the sensor system, which is important for a wearable sensor.