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Suzuki A.,Wakayama University | Ryu K.,Kanai Hospital
IEEE Transactions on Industrial Informatics | Year: 2014

This paper proposes a method for selecting photoplethysmogram features for estimating systolic blood pressure (SBP), which uses the signal-to-noise ratio (SNR) obtained from the Taguchi method. Cuffless estimation of blood pressure using just one photoplethysmograph was carried out based on the photoplethysmogram features. However, these features are highly vulnerable to noise generated by sources such as individual variability, resulting from factors such as age and gender. Therefore, features need to be robust against such noise for accurate estimation of blood pressure. In this study, we used an orthogonal array and the SNR from the Taguchi method for selecting features of multiple regression analysis that are robust against noise. We estimated SBP from two datasets by applying the proposed feature selection method to multiple regression analysis. The obtained results show that the correlation coefficients between the actual measurement values and the estimated values were 0.88 and 0.87 for datasets 1 and 2, which are higher than those of similar methods used for comparison purposes. This confirms the effectiveness of the proposed method in estimating SBP. © 2012 IEEE.


Suzuki A.,Wakayama University | Ryu K.,Kanai Hospital | Kanai N.,Kanai Hospital
IEEJ Transactions on Electrical and Electronic Engineering | Year: 2013

This paper proposes a method for estimating the body temperature using a temperature sensor installed on the inside surface of a blood-pressure cuff{ligature}. It is known that the skin surface temperature changes with the outside temperature so that the human body temperature is kept constant. In this paper, based on this property, the body temperature is estimated from the skin surface temperature and the outside temperature measured concurrently while the blood pressure is measured. Considering the actual situation, the estimation could be diffi{ligature}cult when the temperature of the blood-pressure meter cuff{ligature} is greatly diff{ligature}erent from that of upper arm skin, for example. To solve the problem, we classify in advance various learning samples into multiple classes with diff{ligature}erent sets of parameters to estimate the body temperature. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.


Suzuki A.,Wakayama University | Tsuji Y.,Wakayama University | Ue M.,Wakayama University | Ryu K.,Kanai Hospital
Transactions of Japanese Society for Medical and Biological Engineering | Year: 2014

This paper describes a method for estimating blood pressure by using just one pulse wave sensor. Generally, to be able to measure blood pressure, cuffs are required for applying pressure, blood pressure measurement is time and effort consuming, and continuous measurements cannot be performed. If we are able to measure blood pressure without the use of cuff, we can solve these problems. However, features that obtained by pulse wave sensor are highly vulnerable to noise generated by various factors. In this paper, we evaluated the features using Taguchi’s signal-to-noise ratio, and we extracted the features that are robust against noises. The effectiveness of the proposed method confirmed through the experiment of blood pressure estimation. © 2014, Japan Soc. of Med. Electronics and Biol. Engineering. All rights reserved.


Suzuki A.,Wakayama University | Ryu K.,Kanai Hospital | Kanai N.,Kanai Hospital
IEEJ Transactions on Electronics, Information and Systems | Year: 2011

This paper proposes a method for estimation of a body temperature by using a relation between the upper arm temperature and the atmospheric temperature. Conventional method has measured by armpit or oral, because the body temperature from the body surface is influenced by the atmospheric temperature. However, there is a correlation between the body surface temperature and the atmospheric temperature. By using this correlation, the body temperature can estimated from the body surface temperature. Proposed method enables to measure body temperature by the temperature sensor that is embedded in the blood pressure monitor cuff. Therefore, simultaneous measurement of blood pressure and body temperature can be realized. The effectiveness of the proposed method is verified through the actual body temperature experiment. The proposed method might contribute to reduce the medical staff's workloads in the home medical care, and more. © 2011 The Institute of Electrical Engineers of Japan.

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