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Hardware Implementation of Wearable Cuff-less Blood Pressure Monitoring Module
,
M.Sc. Thesis
Sharif University of Technology
;
Shabany, Mahdi
(Supervisor)
;
Mohammadzade, Hoda
(Supervisor)
Abstract
Hypertension precvalence is 24 and 20.5 percent in men and women, respectively. Continuous Blood Pressure monitoring can provide invaluable information about individuals’ health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This work presents an efficient algorithm, based on the Pulse Arrival Time (PAT), extracted from Electrocardiogram (ECG) and Photopletysmograph (PPG), for the continuous and cuff-less estimation of the Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Mean Arterial Pressure (MAP) values. Methods: The proposed framework estimates the BP values through processing vital...
Modeling Brachial Blood Pressure by Using Finger PPG Signal
, M.Sc. Thesis Sharif University of Technology ; Zahedi, Edmond (Supervisor)
Abstract
Nowadays, all of the devices that measure blood pressure commercially at home are using wrist or arm cuffs preventing the systolic or diastolic blood pressure from being measured continuously. Various parameters such as blood flow with some degree of correlation with blood pressure that can be measured noninvasively have been suggested. However, these parameters do not produce accurate estimates for blood pressure. Pulse Transit Time (PTT) which is defined as the interval between the R peak of ECG signal and the next PPG signal valley has shown to have over 90% correlation with systolic blood pressure in past studies. In this thesis, the relationship between the value of the systolic blood...
2-D Modeling of Blood Flow in Mitral Valve During its Closing and Opening
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; Saeedi, Mohammad Saeed (Co-Supervisor)
Abstract
Problems with the mitral valve can make the heart less efficient at pumping blood around the body. Severe problems can lead to heart failure if the valve is not surgically repaired or replaced. A simple approximation of the heart geometry is used and the valve dimensions are based on reported measurements. The primary objective for this study is to design and simulate the opening and closing behavior of the mitral valve using 2D fluid-structure interaction (FSI) model using ADINA software in order to evaluate and investigate the hemodynamic performance and problems of mitral valve, in which the blood is described as a viscous incompressible fluid, and the mitral valve is described as an...
Design and Implementation of Non-Invasive Blood Pressure Monitor for Smart Health Application
, M.Sc. Thesis Sharif University of Technology ; Fakharzadeh Jahromi, Mohammad (Supervisor)
Abstract
The blood pressure (BP) is one of the most vital signs to monitor human health. Hypertension is a major public health problem that is associated with morbidity and mortality. In the past decades, the number of people with hypertension disease has been increased. According to Ministry of Health, 54 percent of hypertensive patients are unaware of this health threat. Therefore, accurate and continuous measurement of BP is essential for its prevention and treatment. Traditional non-invasive methods of BP monitoring use an inflatable cuff, which causes discomfort due to occlusion of the artery and can not be used continuously. Numerous studies have attempted to present methods without using a...
, M.Sc. Thesis Sharif University of Technology ; Atarodi, Mojtaba (Supervisor) ; Mehrany, Khashayar (Supervisor)
Abstract
In this thesis a novel passive method for integrated blood pressure monitoring in implantable applications has been proposed. The main constraints of such implantable systems are power consumption, area and simplicity of the implanted part and detected pressure is transmitted wirelessly to the external system and recorded. In this thesis an oscillator in 0.18um CMOS process has been proposed to detect the resonance frequency of the implanted tank circuit in the external unit of an implantable blood pressure monitoring system. Other designed circuits include a buffer, frequency detector, voltage to current converter and an 8 bit analog to digital converter. The system is capable of measuring...
Design of Efficient Algorithms for Cuff-less and Continuous Estimation of Blood Pressure in Smart Mobile Healthcare Systems
, M.Sc. Thesis Sharif University of Technology ; Shabany, Mahdi (Supervisor) ; Mohammadzadeh, Hoda (Co-Advisor)
Abstract
Continuous Blood Pressure monitoring can provide invaluable information about individuals’ health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This work presents an efficient algorithm, based on the Pulse Arrival Time (PAT), for the continuous and cuff-less estimation of the Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Mean Arterial Pressure (MAP) values. The proposed framework estimates the BP values through processing vital signals and extracting two types of features, which are based on either physiological parameters or whole-based representation of vital signals. Finally, the...
Simulation of the Influence of Hypertension on Low Density Lipoprotein (Ldl) Permeation into Multilayer Coronary Bifurcation
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor)
Abstract
Atherosclerosis, due to the penetration of low-density lipoprotein particles (LDL) into the arterial wall, is one of the most common and death-leading diseases in today's world. Due to its importance, extensive research has been conducted on the factors that affect this disease. In this thesis, a numerical study of the effects of Wall Shear Stress (WSS), non-Newtonian behavior of blood, different hematocrit values, and blood pressure on LDL permeation through the artery wall layers are investigated in a 4-layer wall model of a coronary bifurcation. To obtain the velocity and concentration fields in the domain, momentum, Brinkman, and mass transport equations are solved in the lumen and wall...
Development of an Integrated Hybrid Model of Human Cardiovascular and Respiratory System for Control Study purposes
, M.Sc. Thesis Sharif University of Technology ; Bozorgmehri, Ramin (Supervisor)
Abstract
Mathematical models are used for describing physical systems to make it possible to study and investigate the behavior of these systems and compare their performance and improve them. For this reason, a mathematical model for cardiovascular system and respiratory system is used to study how these two systems interact. The cardiovascular system model and the respiratory system model comprise four and two compartments, respectively. In fact, the combined model contains the left and right ventricles, body tissue, lung, systemic blood circulation, and pulmonary compartments. Heart rate and alveolar ventilation are assumed to be the quantities through them the central nervous system controls the...
Blood Pressure Estimation from PPG Signal Using Dynamic Time Warping Based Methods
, M.Sc. Thesis Sharif University of Technology ; Mohammadzade, Narjes alhoda (Supervisor) ; Behrozi, Hamid (Co-Supervisor)
Abstract
By continuously measuring blood pressure, we can prevent the irreversible effects of high blood pressure. With the traditional method of using a cuff, it is not possible to measure blood pressure continuously during the day, so for continuous monitoring of blood pressure, it is necessary to use a method without the need for a cuff. Based on previous studies, to estimate blood pressure, Photoplethysmogram and ECG signal features, or temporal and morphological features of Photoplethysmogram signal have been used. In methods that use ECG signals, signal recording is difficult, and methods that use both PPG and ECG signals are even more complex. Using only PPG signals also has its problems....
Blood Pressure Measurement by using Pulse Transit Time
, M.Sc. Thesis Sharif University of Technology ; Zahedi, Edmond (Supervisor) ; Jahed, Mehran (Supervisor)
Abstract
Continuous and non-invasive blood pressure (BP) measurement systems generally utilize applanation tonometry and vascular unloading. Some of them satisfies the AAMI standards (|mean|<5, |SD|<8). Unfortunately they are hardly to be widely affordable due to the complicated mechanical structure and high production cost. Till now those devices are seldom being used in operation room and generally used in clinical researches. In 2000, a linear model using pulse transit time (PTT) to continuous and non-invasive blood pressure (BP) measurement was proposed. Due to the nonlinear performance parameters of the arteries, researchers have used nonlinear models to promote this method. Although the...
Non-invasive and Continuous Blood Pressure Measurement Using Pulse Transit Time without Cuff Requirement
, M.Sc. Thesis Sharif University of Technology ; Shabany, Mahdi (Supervisor)
Abstract
This thesis addresses cuff-less blood pressure (BP) estimation, for systolic blood pressure (SBP) and diastolic blood pressure (DBP) estimation with the aid of the processing of vital signals. Both with and without calibration per person approaches for BP estimation are considered. A data acquisition hardware is designed for high-resolution sampling of phonocardiogram (PCG), Photoplethysmogram (PPG) and electrocardiogram (ECG). Using these signals, pulse transit time (PTT) and pulse arrival time (PAT) indexes, which would be used for BP estimation with calibration, are extracted. For the BP estimator model using the calibration, A nonlinear model based on PTT or PAT, via modeling the vessels...
Time Series Analysis Using Deep Neural Networks Based on DTW Kernels and its Application in Blood Pressure Estimation Using PPG Signals
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Narjesolhoda (Supervisor)
Abstract
This work presents a modification of deep neural networks for time series analysis. We used kernel layer(s), as a novel approach, at the beginning of the common deep neural networks. These kernels learn based on dynamic time warping (DTW). In each kernel, DTW is calculated between the kernel value and a part of input time series or a part of last layer output (if the kernel is not in the first layer). DTW also gives an alignment path for the input series. This alignment path is used to defining a loss function with the goal of getting better alignment (lower DTW distance) between the kernel and the other input. Besides getting better accuracy on the examined datasets, the other achievement...
Validation of the Saadat NIBP module according to the ANSI/AAMI-SP10 protocol
, Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; Deembec , 2013 , Pages 199-202 ; Mashayekhi, G ; Behzadfar, N ; Yaghoobzadeh, A ; Babaee, T ; Sharif University of Technology
IEEE Computer Society
2013
Abstract
This study is conducted with the aim of validating the Saadat non-invasive blood pressure (NIBP) module accuracy and reliability against direct intra arterial pressure measurement (IBP) according to the ANSI/AAMI SP10-2002 guidelines. Measurement and comparison procedure were done in a static population of 19 adult patients with brachial catheterized arterial line with total measurements of 195 under supervision of a highly experienced cardiovascular anesthesiologist in accordance with the ANSI/AAMI SP10-2002 regulation. Data analysis was performed based on the protocol criteria. In order to represent relationships between the test device and the reference method, Bland-Altman graphical...
Utility of a nonlinear joint dynamical framework to model a pair of coupled cardiovascular signals
, Article IEEE Journal of Biomedical and Health Informatics ; Volume 17, Issue 4 , 2013 , Pages 881-890 ; 21682194 (ISSN) ; Shamsollahi, M. B ; Sharif University of Technology
2013
Abstract
We have recently proposed a correlated model to provide a Gaussian mixture representation of the cardiovascular signals, with promising results in identifying rhythm disturbances. The approach provides a transformation of the data into a set of integrable Gaussians distributed over time. Looking into the model from a new joint modeling perspective, it is capable of assembling a filtered estimation, and can be used to derive temporal information of the waveforms. In this paper, we present a step-by-step derivation of the joint model putting correlation assumptions together to conclude a minimal joint description for a pair of ECG-ABP signals. We then probe novel applications of this model,...
Time-dependent analysis of leaflets in mechanical aortic bileaflet heart valves in closing phase using the finite strip method
, Article Medical Engineering and Physics ; Volume 28, Issue 2 , 2006 , Pages 122-133 ; 13504533 (ISSN) ; Ahmadian, M. T ; Wan, W. K ; Sharif University of Technology
2006
Abstract
Background and aims of the study: Mechanical heart valves (MHV) are widely used to replace dysfunctional and failed heart valves. The bileaflet MHV design is very popular due to its superior hemodynamics. Since their introduction in 1977, the hemodynamics of bileaflet prostheses has been extensively studied. In this study the dynamic behaviour during the closing phase of a bileaflet MHV under normal physiological conditions has been investigated. Methods: Fluid analysis is based on the control volume with moving boundaries in the vicinity of the occluder. Unsteady continuity equation, unsteady momentum equation on the control volume and unsteady Bernoulli's equation have been used to...
The Capacity of associated subsequence retrieval
, Article IEEE Transactions on Information Theory ; Volume 67, Issue 2 , 2021 , Pages 790-804 ; 00189448 (ISSN) ; Maddah Ali, M. A ; Motahari, S. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
The objective of a genome-wide association study (GWAS) is to associate subsequences of individuals' genomes to the observable characteristics called phenotypes (e.g., high blood pressure). Motivated by the GWAS problem, in this paper we introduce the information-theoretic problem of associated subsequence retrieval, where a dataset of N (possibly high-dimensional) sequences of length G, and their corresponding observable (binary) characteristics is given. The sequences are chosen independently and uniformly at random from XG , where X is a finite alphabet. The observable (binary) characteristic is only related to a specific unknown subsequence of length L of the sequences, called associated...
Single-replicate longitudinal data analysis in the presence of multiple instrumental measurement errors
, Article Computers and Industrial Engineering ; Volume 141 , 2020 ; Behbahani, M ; Khedmati, M ; Akhavan Niaki, S. T ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this paper, a novel method as a combination of the expectation–maximization (EM) algorithm and Variogram is proposed to decompose the longitudinal measurement errors in the absence of replications and the presence of multiple instrumental measurement errors. In the proposed method, multiple measurements are considered where the units are observed by several distinct instruments (gauges). The approach decouples the observed variance of the measurement model into the process and measurement system variances. In addition, it decomposes the variance of multiple instruments into the process and instrument variances. In the end, the proposed model is validated and tested based on simulated...
Robust control of LVAD based on the sub-regional modeling of the heart
, Article Scientia Iranica ; Volume 23, Issue 6 , 2016 , Pages 2934-2943 ; 10263098 (ISSN) ; Jahed, M ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
Left Ventricular Assist Devices (LVAD) have received renewed interest as a bridge-to-transplantation as well as a bridge-to-recovery device. Ironically, reports of malfunction and complications have hindered the growth of this device. In particular, the main concern is LVAD's susceptibility to excessive backlash and suction as a result of ows that are either too low or high, respectively. This study utilizes a well-established physiological model of the cardiovascular system as a reliable platform to study a proposed adaptive robust controller for a rotary motor based LVAD which overcomes such shortcomings. Proposed controller performance is evaluated by comparing simulated natural heart...
Reducing the risk of death induced by aluminum phosphide poisoning: The new therapies
, Article Chemosphere ; Volume 294 , 2022 ; 00456535 (ISSN) ; Abouei Mehrizi, A ; Eghbal, M. A ; Ghazi Khansari, M ; Azarmi, Y ; Sattari, M. R ; Karaman, C ; Karimi, F ; Alizadeh, M ; Yazdani, M. N ; Hosseinpour, P ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Numerous people suffer from accidental or deliberate exposure to different pesticides when poisoning with aluminum phosphate (AlP) is increasing in the eastern countries. Aluminum phosphate is a conventional insecticide that quickly reacts with water or the moistures in the atmosphere and produces fatal phosphine gas, which absorbs quickly by the body. Oral consumption or inhalation of AlP leads to excessive reaction of the body such as fatigue, vomiting, fever, palpitation, vasodilatory shock, increasing blood pressure, cardiac dysfunction, pulmonary congestion, shortness of breath, and death. The garlic smell from the patient's mouth or exhale is one of the methods to recognize the...
Primary stenosis progression versus secondary stenosis formation in the left coronary bifurcation: a mechanical point of view
, Article Biocybernetics and Biomedical Engineering ; Volume 39, Issue 1 , 2019 , Pages 188-198 ; 02085216 (ISSN) ; Pakravan, H. A ; Saidi, M. S ; Firoozabadi, B ; Sharif University of Technology
Elsevier Sp. z o.o
2019
Abstract
Biomechanical forces and hemodynamic factors influence the blood flow and the endothelial cells (ECs) morphology. These factors behave differently beyond the coronary artery stenosis. In the present study, unsteady blood flow in the left coronary artery (LCA) and its atherosclerotic bifurcating vessels, left anterior descending (LAD) and left circumflex (LCX) arteries, were numerically simulated to investigate the risk of plaque length development and secondary plaque formation in the post-stenotic areas. Using fluid–structure interaction (FSI) model, compliance of arterial wall and vessel curvature variations due to cardiac motion were considered. The arteries included plaques at the...