Biomedical Signal Processing and Control 47 (2019) 196–206 Contents lists available at ScienceDirect Biomedical Signal Processing and Control jo ur nal homep age: www.elsevier.com/locate/bspc Blood pressure estimation from appropriate and inappropriate PPG signals using A whole-based method Seyedeh Somayyeh Mousavi a , Mohammad Firouzmand b , Mostafa Charmi a,∗ , Mohammad Hemmati a , Maryam Moghadam c , Yadollah Ghorbani d a Department of Electrical Engineering, University of Zanjan, Zanjan, Iran b Department of Biomedical Engineering, Iranian Research Organization for Science & Technology (IROST), Tehran, Iran c Department of Biomedical Engineering, Amirkabir University of Technology (Tehran-Polytechnic), Tehran, Iran d Medical Equipment Section, Valiasr Hospital, Zanjan University of Medical Sciences, Zanjan, Iran a r t i c l e i n f o Article history: Received 17 May 2018 Received in revised form 16 July 2018 Accepted 20 August 2018 Keywords: Blood pressure Photoplethysmography Whole-based Parameter-based Cuff-less a b s t r a c t Background and objective: Blood pressure (BP) is one of the four vital signals that provides valuable medical information about the cardiovascular activity. In recent years, extensive studies have been conducted on non-invasive and cuff-less BP estimation using photoplethysmography (PPG) signals. PPG is a non- invasive optical method for measuring blood volume changes per pulse. In other words, the PPG waveform represents the mechanical activity of the heart. Methods: In this paper, a new method for estimating the Mean Arterial Pressure (MAP), Diastolic Blood Pressure (DBP) and Systolic Blood Pressure (SBP) is proposed using only the PPG signal regardless of its shape (appropriate or inappropriate). Our proposed algorithm called whole-based, uses raw values of the PPG signal at a given time interval for estimating the BP. In other algorithms called parameter-based, use features which are extracted from PPG signals in time or frequency domain. These features related to precise spotting in the form of the PPG signal. In fact, compared to parameter-based methods, our algorithm is independent of the form of the PPG signal. Results: Using the proposed algorithm, our results are completely met by the Association for the Advance- ment of Medical Instrumentation (AAMI) standard for both MAP and DBP estimations. The results are also very close to the standard boundary with an average error close to zero for SBP estimation. Also, according to the British Hypertension Society (BHS) standard, the proposed algorithm for DBP estima- tion got grade A, whereas it got grade B for estimation of MAP and got approximately grade C for SBP estimation. Conclusion: The results demonstrate the applicability of the proposed algorithm in estimating BP nonin- vasively, cuff-less, calibration-free, and only by using the appropriate or inappropriate PPG signal. © 2018 Elsevier Ltd. All rights reserved. 1. Introduction Cardiovascular disease is one of the most important causes of death in the world. According to the report of the European Heart Journal, 4.1 million people die annually due to this disease [1]. Hypertension is the main cause of cardiovascular disease. In 2014, the prevalence of hypertension was 1.3 billion people worldwide ∗ Corresponding author at: Room 101, Department of Electrical Eng., Faculty of Eng., University of Zanjan, University Blvd, 45371-38791, Zanjan, Iran. E-mail addresses: s.somaiie.mousavie@znu.ac.ir (S.S. Mousavi), firouzmand@irost.org (M. Firouzmand), charmi.mostafa@znu.ac.ir (M. Charmi), m hemmati@znu.ac.ir (M. Hemmati), moghadam.m@aut.ac.ir (M. Moghadam), yadollah gh@yahoo.com (Y. Ghorbani). as such, it is anticipated that by 2030, 1.56 billion people will suffer from hypertension [2,3]. Blood pressure (BP) is one of the significant parameters of the human body whose measurement provides valuable information for physicians. Frequent BP measurement can avail early detec- tion, control, and treatment of diseases associated with BP such as hypotension and hypertension [4]. BP shows the resistance of the body vessels to the movement of the blood and its amount depends on the function of the heart and vascular features, such as elastic- ity and thickness of the walls of the vessel [5]. The upper and lower bounds of this pressure are called Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP), respectively [6]. Another BP called Mean Arterial Blood Pressure (MAP) can be approximated to the following equation: MAP = (2DBP + SBP)/3 (1) https://doi.org/10.1016/j.bspc.2018.08.022 1746-8094/© 2018 Elsevier Ltd. All rights reserved.