PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature

This paper proposes a cuff-less systolic blood pressure (SBP) estimation method using partial least-squares (PLS) regression. Level-crossing features (LCFs) were used in this method, which were extracted from the contour lines arbitrarily drawn on the second-derivative photoplethysmography waveform....

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Main Authors: Daisuke Fujita, Arata Suzuki, Kazuteru Ryu
Format: Article
Language:English
Published: MDPI AG 2019-01-01
Series:Applied Sciences
Subjects:
Online Access:http://www.mdpi.com/2076-3417/9/2/304
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author Daisuke Fujita
Arata Suzuki
Kazuteru Ryu
author_facet Daisuke Fujita
Arata Suzuki
Kazuteru Ryu
author_sort Daisuke Fujita
collection DOAJ
description This paper proposes a cuff-less systolic blood pressure (SBP) estimation method using partial least-squares (PLS) regression. Level-crossing features (LCFs) were used in this method, which were extracted from the contour lines arbitrarily drawn on the second-derivative photoplethysmography waveform. Unlike conventional height ratio features (HRFs), which are extracted on the basis of the peaks in the waveform, LCFs can be reliably extracted even if there are missing peaks in the waveform. However, the features extracted from adjacent contour lines show similar trends; thus, there is a strong correlation between the features, which leads to multicollinearity when conventional multiple regression analysis (MRA) is used. Hence, we developed a multivariate estimation method based on PLS regression to address this issue and estimate the SBP on the basis of the LCFs. Two-hundred-and-sixty-five subjects (95 males and 170 females [(Mean ± Standard Deviation) SBP: 133.1 ± 18.4 mmHg; age: 62.8 ± 16.8 years] participated in the experiments. Of the total number of subjects, 180 were considered as learning data, while 85 were considered as testing data. The values of the correlation coefficient between the measured and estimated values were found to be 0.78 for the proposed method (LCFs + PLS), 0.58 for comparison method 1 (HRFs + MRA), and 0.62 for comparison method 2 (HRFs + MRA). The proposed method was therefore found to demonstrate the highest accuracy among the three methods being compared.
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spelling doaj.art-0ba82c60d55d415e8712411689b3ca842022-12-21T18:54:45ZengMDPI AGApplied Sciences2076-34172019-01-019230410.3390/app9020304app9020304PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing FeatureDaisuke Fujita0Arata Suzuki1Kazuteru Ryu2Faculty of Systems Engineering, Wakayama University, Sakaedani 930, Wakayama 640-8510, JapanFaculty of Systems Engineering, Wakayama University, Sakaedani 930, Wakayama 640-8510, JapanKanai Hospital, 681 Higashigumi-chō, Fushimi-ku, Kyoto-shi, Kyoto 612-8511, JapanThis paper proposes a cuff-less systolic blood pressure (SBP) estimation method using partial least-squares (PLS) regression. Level-crossing features (LCFs) were used in this method, which were extracted from the contour lines arbitrarily drawn on the second-derivative photoplethysmography waveform. Unlike conventional height ratio features (HRFs), which are extracted on the basis of the peaks in the waveform, LCFs can be reliably extracted even if there are missing peaks in the waveform. However, the features extracted from adjacent contour lines show similar trends; thus, there is a strong correlation between the features, which leads to multicollinearity when conventional multiple regression analysis (MRA) is used. Hence, we developed a multivariate estimation method based on PLS regression to address this issue and estimate the SBP on the basis of the LCFs. Two-hundred-and-sixty-five subjects (95 males and 170 females [(Mean ± Standard Deviation) SBP: 133.1 ± 18.4 mmHg; age: 62.8 ± 16.8 years] participated in the experiments. Of the total number of subjects, 180 were considered as learning data, while 85 were considered as testing data. The values of the correlation coefficient between the measured and estimated values were found to be 0.78 for the proposed method (LCFs + PLS), 0.58 for comparison method 1 (HRFs + MRA), and 0.62 for comparison method 2 (HRFs + MRA). The proposed method was therefore found to demonstrate the highest accuracy among the three methods being compared.http://www.mdpi.com/2076-3417/9/2/304blood pressure estimationphotoplethysmographypartial least-squares regression
spellingShingle Daisuke Fujita
Arata Suzuki
Kazuteru Ryu
PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature
Applied Sciences
blood pressure estimation
photoplethysmography
partial least-squares regression
title PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature
title_full PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature
title_fullStr PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature
title_full_unstemmed PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature
title_short PPG-Based Systolic Blood Pressure Estimation Method Using PLS and Level-Crossing Feature
title_sort ppg based systolic blood pressure estimation method using pls and level crossing feature
topic blood pressure estimation
photoplethysmography
partial least-squares regression
url http://www.mdpi.com/2076-3417/9/2/304
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AT aratasuzuki ppgbasedsystolicbloodpressureestimationmethodusingplsandlevelcrossingfeature
AT kazuteruryu ppgbasedsystolicbloodpressureestimationmethodusingplsandlevelcrossingfeature