Loading...
Search for:
blood
0.008 seconds
Total 330 records
Development of a non-invasive micron sized blood glucose sensor based on microsphere stimulated raman spectroscopy
, Article Sensors and Transducers ; Volume 147, Issue 12 , 2012 , Pages 129-142 ; 17265479 (ISSN) ; Jahangiri, N ; Taraz, M ; Sharif University of Technology
2012
Abstract
We proposed a new method for Non-invasive measuring of blood glucose levels by using micro sphere Stimulated Raman scattering. We show that this method can be used to measure biological glucose levels with low power lasers. The field enhancement due to the resonance condition of high quality factor microsphere causes to reduce stimulated Raman scattering thresholds of its surrounding media (glucose) and hence observing stimulated Raman scattering with low power. The results from theoretical studies indicate that the stimulated Raman signal amplitude levels produced from the very low Glucose concentrations. By measuring the changes of the signal intensity in output of fiber, we can determine...
Mathematical study of probe arrangement and nanoparticle injection effects on heat transfer during cryosurgery
, Article Computers in Biology and Medicine ; Volume 66 , Nov , 2015 , Pages 113-119 ; 00104825 (ISSN) ; Ramazani S. A. A ; Nazemidashtarjandi, S ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Blood vessels, especially large vessels have a greater thermal effect on freezing tissue during cryosurgery. Vascular networks act as heat sources in tissue, and cause failure in cryosurgery and reappearance of cancer. The aim of this study is to numerically simulate the effect of probe location and multiprobe on heat transfer distribution. Furthermore, the effect of nanoparticles injection is studied. It is shown that the small probes location near large blood vessels could help to reduce the necessary time for tissue freezing. Nanoparticles injection shows that the thermal effect of blood vessel in tissue is improved. Using Au, Ag and diamond nanoparticles have the most growth of ice ball...
A combined dynamical sequential network for generating coupled cardiovascular signals with different beat types
, Article ; 2010 3rd International Symposium on Applied Sciences in Biomedical and Communication Technologies, ISABEL 2010, 7 November 2010 through 10 November 2010 , 2010 ; 9781424481323 (ISBN) ; Shamsollahi, M. B ; Sharif University of Technology
Abstract
We present generalizations of the previously published artificial models for generating abnormal cardiac rhythms to provide simulations of coupled cardiovascular (CV) signals with different beat morphologies. Using a joint dynamical formulation, we generate the normal morphologies of the cardiac cycle using a sum of Gaussian kernels, fitted to real CV recordings. The joint inter-dependencies of CV signals are introduced by assuming the same angular frequency and a phase coupling. Abnormal beats are then specified as new dynamical trajectories. An ergadic first-order Markov chain is also used for switching between normal and abnormal beat types. Probability transitions can be learned from...
Leukocyte's nucleus segmentation using active contour in YCbCr colour space
, Article Proceedings of 2010 IEEE EMBS Conference on Biomedical Engineering and Sciences, IECBES 2010, 30 November 2010 through 2 December 2010, Kuala Lumpur ; 2010 , Pages 257-260 ; 9781424476008 (ISBN) ; Jahed, M ; Salehian, P ; Eslami, A ; Sharif University of Technology
2010
Abstract
Blood cell segmentation is a crucial part of many medical and laboratory procedures such as cell counting and blood cell disorder diagnosis. Among different types of blood cells, white blood cells are the most important clinically, as they suffer greatest from blood disorders. In this paper we propose a method for automatic segmentation of white blood cells nucleus. A distinctive function is used in YCbCr color space to segment the white blood cells nucleus. Next, the sub-images are extracted which contain the whole body of white blood cell nucleus. Then an active contour method is applied to the sub-images extracted from the previous step to accurately segment the cell nucleus boundary. Our...
Investigation of a two-step device implementing magnetophoresis and dielectrophoresis for separation of circulating tumor cells from blood cells
, Article Engineering in Life Sciences ; Volume 20, Issue 7 , 2020 , Pages 296-304 ; Yazdani, A ; Saghafifar, F ; Sharif University of Technology
Wiley-VCH Verlag
2020
Abstract
Identifying tumor cells from a pool of other cells has always been an appealing topic for different purposes. The objective of this study is to discriminate circulating tumor cells (CTCs) from blood cells for diagnostic purposes in a novel microfluidic device using two active methods: magnetophoresis and dielectrophoresis. The most specific feature of this device is the differentiation of CTCs without labeling them in order to achieve a more reliable and less complicated method. This device was analyzed and evaluated using finite element method. Four cell lines are separated in this device containing red blood cells, platelets, white blood cells, and CTCs. Primarily, red blood cells and...
Comparative approach for detection of biosurfactant-producing bacteria isolated from Ahvaz petroleum excavation areas in south of Iran
, Article Annals of Microbiology ; Volume 58, Issue 3 , 2008 , Pages 555-559 ; 15904261 (ISSN) ; Bagheri Lotfabad, T ; Roostaazad, R ; Rouholamini Najafabadi, A ; Akbari Noghabi, K ; Sharif University of Technology
University of Milan
2008
Abstract
The current study was undertaken to compare four analytical methods including drop collapse, oil spreading, surface tension (SFT) measurements, and blood agar lysis tests for detection of biosurfactant-producing bacteria. Among 32 biosurfactant-producing bacteria isolated from Ahvaz oil fields, in south of Iran, 16 isolates (50%) exhibited highest biosurfactant production. Eleven isolates (MASH.1 to MASH.11) demonstrated a reduction in surface tension from 65 mN/m to less than 41 mN/m. The results showed that about 91% of these highly biosurfactant producers had the same response levels of "++++" and "+++" in the case of both SFT and oil spreading methods. Among these, seven isolates had the...
Computational simulation of non-Newtonian blood flow in carotid bifurcation for investigation the various rheological blood models
, Article ASME 2007 International Mechanical Engineering Congress and Exposition, IMECE 2007, 11 November 2007 through 15 November 2007 ; Volume 2 , 2007 , Pages 263-270 ; 0791842967 (ISBN) ; Firoozabadi, B ; Goodarzvand Chegini, A ; ASME ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2007
Abstract
One of the leading causes for death after heart diseases and cancer in all over the world is still stroke. Most strokes happen because an artery carrying blood from the heart to the brain is clogged. Most of the time, as with heart attacks, the problem is atherosclerosis, hardening of the arteries, calcified build up of fatty deposits on the vessel wall. The primary troublemaker is the carotid artery, one on each side of the neck, the main thoroughfare for blood to the brain. In this study, the fluid dynamic simulations were done in the carotid bifurcation artery for studying the formation of atherosclerosis, and shear thinning behavior of blood as well as Newtonian comportment was studied....
Probabilistic CFD analysis on the flow field and performance of the FDA centrifugal blood pump
, Article Applied Mathematical Modelling ; Volume 109 , 2022 , Pages 555-577 ; 0307904X (ISSN) ; Karimi, M. S ; Raisee, M ; Sharbatdar, M ; Sharif University of Technology
Elsevier Inc
2022
Abstract
The present study is set out to systematically investigate the combined impact of operational, geometrical, and model uncertainties on the hemodynamics and performance characteristics in the U.S. Food and Drug Administration (FDA) benchmark centrifugal blood pump. Non-intrusive Polynomial Chaos Expansion (NIPCE) has been utilized to propagate the uncertainty of 12 random input variables in the flow field and the performance characteristics of the blood pump at three working conditions. The global sensitivity of the Quantities of Interest (QoI) to the uncertain input parameters was measured through the Sobol’ indices. The Multiple Reference Frames (MRF) approach and the SST k−ω turbulence...
Investigation of coronary artery tortuosity with atherosclerosis: A study on predicting plaque rupture and progression
, Article International Journal of Mechanical Sciences ; Volume 223 , 2022 ; 00207403 (ISSN) ; Fallah, F ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
This study investigated the effects of different patterns of coronary artery tortuosity (CAT) on the stress concentration of the plaques and the blood flow pattern inside an atherosclerotic artery to predict the risk of plaque rupture and progression. Four different loadings of the coronary artery, including pulsatile blood pressure as well as one-end twist around the artery axis at blood pressures of 74, 100, and 120 mmHg were considered. No study has addressed bent and twist buckling of an atherosclerotic artery considering pulsatile flow (for bent buckling), fluid-solid interaction, and different geometrical parameters of the plaque. The results showed that C-shape tortuosity under...
Delay-Independent regulation of blood glucose for type-1 diabetes mellitus patients via an observer-based predictor feedback approach by considering quantization constraints
, Article European Journal of Control ; Volume 63 , 2022 , Pages 240-252 ; 09473580 (ISSN) ; Tavazoei, M. S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Diabetes, as a widespread chronic disease, is caused by the increase of blood glucose concentration (BGC) due to pancreatic insulin production failure and/or insulin resistance in the body. The artificial pancreas (AP) known as a closed-loop insulin delivery control system consists of a glucose sensor for BGC measurement, a control algorithm for calculation of exogenous insulin delivery rate (IDR), and an insulin infusion pump. The AP provides a closed-loop glucose-insulin regulatory system for type-1 diabetes mellitus (T1DM) patients in order to effectively reduce the high BGC level. In this paper, we aim to design a controller in order to regulate the BGC of T1DM patients at its basal...
Numerical study of the effect of vascular bed on heat transfer during high intensity focused ultrasound (HIFU) ablation of the liver tumor
, Article Journal of Thermal Biology ; Volume 86 , 2019 ; 03064565 (ISSN) ; Firoozabadi, B ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this study, the influence of vascular bed comprising terminal arterial branches on heat transfer in a liver tumor exposed to high intensity focused ultrasound (HIFU) is studied numerically. Also, the effect of vascular density on temperature distribution is investigated. A coupled set of acoustics, thermal, and fluid models is used to calculate the temperature distribution in the liver. The numerical model is established based on the Westervelt and bioheat equations along with the Navier-Stokes equations. Moreover, the acoustic streaming effect is included with Newtonian and non-Newtonian flow assumptions. It is found that in a vascular bed comprising terminal arterial branches, the...
Subcutaneous insulin administration by deep reinforcement learning for blood glucose level control of type-2 diabetic patients
, Article Computers in Biology and Medicine ; Volume 148 , 2022 ; 00104825 (ISSN) ; Niazmand, V. R ; Eqra, N ; Vatankhah, R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Background: Type-2 diabetes mellitus is characterized by insulin resistance and impaired insulin secretion in the human body. Many endeavors have been made in terms of controlling and reducing blood glucose via the medium of automated controlling tools to increase precision and efficiency and reduce human error. Recently, reinforcement learning algorithms are proved to be powerful in the field of intelligent control, which was the motivation for the current study. Methods: For the first time, a reinforcement algorithm called normalized advantage function (NAF) algorithm has been applied as a model-free reinforcement learning method to regulate the blood glucose level of type-2 diabetic...
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...
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...
Design and Manufacturing of Left Ventricular Assist Device for Patients Undergoing Cardiac Surgery
, M.Sc. Thesis Sharif University of Technology ; Ahmadian, Mohammad Taghi (Supervisor) ; Firouzbakhsh, Keikhosrow (Supervisor)
Abstract
The heart is a powerful muscle whose primary function is to pump blood into the body. many cardiac patients reach a stage that can no longer be kept function of their heart to a satisfactory level by using medication thus doctors undergo surgery. The common problem occurs to most patients undergoing cardiac surgery is that after the surgery, the patient's heart during a short period of time is unable to supply blood with the flow rate and pressure required for all organs, especially the end organs of the body. In this conditions, ventricular assist device help the patients. These devices are used parallel with patient’s heart and supply the large portion of blood that patient’s body needs....
Robust Optimization of Centralized and Decentralized Blood Supply Chain with Considering Blood Group Compatibility
, M.Sc. Thesis Sharif University of Technology ; Kianfar, Farhad (Supervisor)
Abstract
Blood supply chains play a key role in the healthcare systems. Any improvement in the management of these chains have a direct impact on the whole healthcare system. In this research two model for centralized and decentralized blood supply chain networks have been developed by mixed integer linear programming. These models are multi-periodic and include both tactical and strategical decisions for the several periods. In this research the blood group compatibility has been considered in the models, also demand and supply of blood have been considered uncertain, and due to this reason in order to deal with the uncertainty of model the robust Possibilistic programming has been utilized to find...
Control Algorithm of Multi-agent Systems in Special Paths With an Applied Consideration in Biomechanical Engineering to Perform Operations of Interior Treatments
, M.Sc. Thesis Sharif University of Technology ; Sayyadi, Hassan (Supervisor)
Abstract
In this project Deployment of multi-agent systems was studied. Maximum coverage over a point or curve or area is desired in deployment of multi-agent systems. A facility location optimization function was derived from geometrical concepts such as voronoi, n- geometric median and fermat-weber problem by optimization of which the deployment of multi-agent systems is performed. First, it is assumed that dynamic of agents is first order and second order .Next, it is assumed that agents are in a fluid. In all situations a suitable control algorithm was derived to optimize the facility location function to perform deployment. Next, another facility location function was derived by optimization...
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...
Improvement and Implementation of Bio-Inspired Model HMAX in order to Recognize Red Blood Cells Morphology
, M.Sc. Thesis Sharif University of Technology ; Vosoughi Vahdat, Bijan (Supervisor) ; Gholampour, Eiman (Co-Advisor)
Abstract
Blood is the most important liquid in human body. Red blood cells (RBCs) are the main part of blood. RBCs are rounded, but this shape would be changed during different disease. Blood tests taken to diagnose blood diseases. Current instruments do not provide any information about RBCs morphology, and an expert recognize the RBCs morphology by looking at blood smear under microscope. Regards to low accuracy and performance of this method, an automate method must be presented. Capturing images from blood smear under microscope is simple and low-cost. Although there is few methods on RBCs detection and very limited one on RBCs recognition on the literature, no general method to recognize most of...
Blood Glucose Control for Type 1 Diabetes Patients with Explicit Model Predictive Control (MPC)
, M.Sc. Thesis Sharif University of Technology ; Alasty, Aria (Supervisor) ; Vahidi, Omid (Co-Supervisor)
Abstract
Blood glucose regulation in type 1 diabetes patients requires the delivery of the proper amount of insulin from an external source. The literature of Blood Glucose Control signifies the superiority of model-based controllers over the other ones. Regarding its lack of need to complicated on-line calculations and the simplicity of its implementation on a micro-chip, the explicit Model Predictive Controller is preferred over the implicit MPC. Currently proposed explicit MPC controllers have employed relatively simple models representing human glucose-insulin dynamics. In this thesis, an explicit MPC controller is designed using mp-QP based on Sorensen’s 19-state comprehensive model which has...