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https://www.readbyqxmd.com/read/28227765/distribution-aware-estimation-of-the-minimum-achievable-uncertainty-in-diffusion-tensor-imaging-dti
#1
Andrea Duggento, Marco Giannelli, Carlo Tessa, Simona Lanzafame, Maria Guerrisi, Nicola Toschi, Andrea Duggento, Marco Giannelli, Carlo Tessa, Simona Lanzafame, Maria Guerrisi, Nicola Toschi, Nicola Toschi, Maria Guerrisi, Marco Giannelli, Carlo Tessa, Simona Lanzafame, Andrea Duggento
Diffusion tensor imaging (DTI) provides exquisite sensitivity to structural and microstructural characteristics of brain tissue, and is routinely employed in advanced neuroimaging applications. DTI is commonly performed using intrinsically noisy echo-planar imaging techniques and poses high demands both on scanner performance and on in-scanner subject time, which in turn is directly related to the number of diffusion-weighting direction one requires. While DTI-derived indices such as fractional anisotropy (FA), diffusion tensor trace and anisotropy mode have proven extremely useful in characterizing disease-related aberrations, their estimation is commonly performed using fitting routines that do not properly take into account MRI noise distribution...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227692/current-distribution-in-tissues-with-conducted-electrical-weapons-operated-in-drive-stun-mode
#2
Dorin Panescu, Mark W Kroll, Michael Brave, Dorin Panescu, Mark W Kroll, Michael Brave, Dorin Panescu, Mark W Kroll, Michael Brave
INTRODUCTION: The TASER® conducted electrical weapon (CEW) is best known for delivering electrical pulses that can temporarily incapacitate subjects by overriding normal motor control. The alternative drive-stun mode is less understood and the goal of this paper is to analyze the distribution of currents in tissues when the CEW is operated in this mode. METHODS AND RESULTS: Finite element modeling (FEM) was used to approximate current density in tissues with boundary electrical sources placed 40 mm apart...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227539/robot-assisted-assessment-of-wrist-proprioception-does-wrist-proprioceptive-acuity-follow-weber-s-law
#3
Sara Contu, Francesca Marini, Leonardo Cappello, Lorenzo Masia, Sara Contu, Francesca Marini, Leonardo Cappello, Lorenzo Masia, Lorenzo Masia, Sara Contu, Leonardo Cappello, Francesca Marini
Proprioception is essential for planning and controlling limb posture and movement. In our recent work, we introduced a standardized robot-aided method for measuring proprioceptive discrimination thresholds at the wrist to obtain reliable and accurate measures of proprioceptive acuity. Weber's law defines discrimination thresholds as a constant ratio between the just noticeable difference and the reference or standard stimulus. Reporting Weber's fractions thus provides the possibility of comparing results with the reports of others collected worldwide...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227463/hemodynamic-effects-of-synchronizing-an-intra-aortic-vad-in-reverse-rotation-control-with-left-ventricle-a-mock-loop-study
#4
Yaxin Wang, P Alex Smith, Daniel L Timms, Po-Lin Hsu, Richard A McMahon, Yaxin Wang, P Alex Smith, Daniel L Timms, Po-Lin Hsu, Richard A McMahon, Richard A McMahon, Daniel L Timms, Po-Lin Hsu, Yaxin Wang, P Alex Smith
The IntraVAD is an intra-aortic left ventricular assist device (LVAD) to be located in the ascending aorta. In order to enhance unloading and promote coronary flow for the left ventricle (LV), an operating mechanism, reverse-rotation control (RRc) mode, has been developed for the IntraVAD and tested in vitro in a mock circulation loop (MCL). The RRc mode consists of forward rotation (FR) and reverse rotation (RR). The synchronization between the IntraVAD and the LV was studied to offload the ventricle more effectively and to improve myocardial perfusion...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227426/characterization-of-patient-specific-biventricular-mechanics-in-heart-failure-with-preserved-ejection-fraction-hyperelastic-warping
#5
Hua Zou, Xiaodan Zhao, Xi Ce, Lik Chuan Lee, Martin Genet, Yi Su, Rusan Tan, Liang Zhong, Hua Zou, Xiaodan Zhao, Xi Ce, Lik Chuan Lee, Martin Genet, Yi Su, Rusan Tan, Liang Zhong, Rusan Tan, Martin Genet, Hua Zou, Lik Chuan Lee, Yi Su, Liang Zhong, Xiaodan Zhao, Xi Ce
Heart failure with preserved ejection fraction (HFPEF) is considered as a major public health problem. Traditionally, HFPEF is diagnosed based on a "normal" EF, but the studies have explored the potential role of left ventricular mechanics. Furthermore, right ventricular mechanics and bi-ventricular interaction in HFPEF is currently not well understood. In this study, we aim to develop a framework using a hyperelastic warping approach to quantify bi-ventricular and septum strains from cardiac magnetic resonance (CMR) images...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227361/kinect2-respiratory-movement-detection-study
#6
Sandy Rihana, Elie Younes, Dimitris Visvikis, Hadi Fayad, Sandy Rihana, Elie Younes, Dimitris Visvikis, Hadi Fayad, Sandy Rihana, Elie Younes, Dimitris Visvikis, Hadi Fayad
Radiotherapy is one of the main cancer treatments. It consists in irradiating tumor cells to destroy them while sparing healthy tissue. The treatment is planned based on Computed Tomography (CT) and is delivered over fractions during several days. One of the main challenges is replacing patient in the same position every day to irradiate the tumor volume while sparing healthy tissues. Many patient positioning techniques are available. They are both invasive and not accurate performed using tattooed marker on the patient's skin aligned with a laser system calibrated in the treatment room or irradiating using X-ray...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227289/modeling-volatility-in-heat-rate-variability
#7
Argentina Leite, Maria Eduarda Silva, Ana Paula Rocha, Argentina Leite, Maria Eduarda Silva, Ana Paula Rocha, Argentina Leite, Ana Paula Rocha, Maria Eduarda Silva
Modeling Heart Rate Variability (HRV) data has become important for clinical applications and as a research tool. These data exhibit long memory and time-varying conditional variance (volatility). In HRV, volatility is traditionally estimated by recursive least squares combined with short memory AutoRegressive (AR) models. This work considers a parametric approach based on long memory Fractionally Integrated AutoRegressive Moving Average (ARFIMA) models with heteroscedastic errors. To model the heteroscedasticity nonlinear Generalized Autoregressive Conditionally Heteroscedastic (GARCH) and Exponential Generalized Autoregressive Conditionally Heteroscedastic (EGARCH) models are considered...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227221/fundamentals-of-left-ventricular-volume-representation
#8
Peter L Kerkhof, Peter L Kerkhof, Peter L Kerkhof
The volume regulation graph is meant to relate the fundamental determinants of left ventricular (LV) function, namely end-systolic volume (ESV) and end-diastolic volume (EDV). This representation permits evaluation of the LV remodeling process, convenient stratification for clinically relevant covariates, as well as inscription of iso-stroke volume (SV) and iso-ejection fraction (EF) trajectories, the latter two as linear relationships. This retrospective study discusses LV volumetric parameters obtained from 155 patients (65 females) covering a wide spectrum of heart diseases...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227219/hemodynamic-determinants-and-ventriculo-arterial-coupling-are-sex-associated-in-heart-failure-patients
#9
Peter L Kerkhof, Guy R Heyndrickx, John K-J Li, Peter L Kerkhof, Guy R Heyndrickx, John K-J Li, Peter L Kerkhof, John K J Li, Guy R Heyndrickx
End-systolic volume (ESV) and end-diastolic volume (EDV) are key parameters in the analysis of left ventricular (LV) function, and the study of cardiac remodeling. The volume regulation graph (VRG) relates these fundamental determinants, and permits convenient stratification for clinically relevant covariates. This contribution analyzes sex-associated differences in hemodynamic parameters for 197 heart failure (HF) patients, evaluated by biplane ventriculography, in combination with arterial pressure. We calculated LV parameters such as stroke volume (SV), cardiac output (CO), ESV, EDV, ejection fraction (EF), end-systolic elastance (Emax), besides arterial parameters: effective arterial elastance (Ea), elastance ratio (the coupling index k), peripheral resistance (Rs), pulse pressure (PP), and arterial compliance (C), all normalized for body surface area when appropriate...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227205/low-frequency-ultrasound-radiosensitization-and-therapy-response-monitoring-of-tumors-an-in-vivo-study
#10
Ali Sadeghi-Naini, Martin Stanisz, Hadi Tadayyon, Jaswinder Taank, Gregory J Czarnota, Ali Sadeghi-Naini, Martin Stanisz, Hadi Tadayyon, Jaswinder Taank, Gregory J Czarnota, Jaswinder Taank, Hadi Tadayyon, Martin Stanisz, Ali Sadeghi-Naini, Gregory J Czarnota
A new framework has been introduced in this paper for tumor radiosensitization and therapy response monitoring using low-frequency ultrasound. Human fibrosarcoma xenografts grown in severe combined immunodeficiency (SCID) mice (n = 108) were treated using ultrasound-stimulated microbubbles at various concentration and exposed to different doses of radiation. Low-frequency ultrasound radiofrequency (RF) data were acquired from tumors prior to and at different times after treatment. Quantitative ultrasound (QUS) techniques were applied to generate spectral parametric maps of tumors...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227076/analysis-of-blood-pressure-signal-in-patients-with-different-ventricular-ejection-fraction-using-linear-and-non-linear-methods
#11
Andres Arcentales, Patricio Rivera, Pere Caminal, Andreas Voss, Antonio Bayes-Genis, Beatriz F Giraldo, Andres Arcentales, Patricio Rivera, Pere Caminal, Andreas Voss, Antonio Bayes-Genis, Beatriz F Giraldo, Pere Caminal, Antonio Bayes-Genis, Andres Arcentales, Patricio Rivera, Beatriz F Giraldo, Andreas Voss
Changes in the left ventricle function produce alternans in the hemodynamic and electric behavior of the cardiovascular system. A total of 49 cardiomyopathy patients have been studied based on the blood pressure signal (BP), and were classified according to the left ventricular ejection fraction (LVEF) in low risk (LR: LVEF>35%, 17 patients) and high risk (HR: LVEF≤35, 32 patients) groups. We propose to characterize these patients using a linear and a nonlinear methods, based on the spectral estimation and the recurrence plot, respectively...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227067/computational-estimation-of-the-severity-of-coronary-lesions-with-intravascular-ultrasound-images-a-pilot-study
#12
Panagiotis K Siogkas, Michail I Papafaklis, Bill D Gogas, Habib Samady, Lampros K Michalis, Dimitrios I Fotiadis, Panagiotis K Siogkas, Michail I Papafaklis, Bill D Gogas, Habib Samady, Lampros K Michalis, Dimitrios I Fotiadis, Bill D Gogas, Habib Samady, Michail I Papafaklis, Dimitrios I Fotiadis, Panagiotis K Siogkas, Lampros K Michalis
The fast and accurate hemodynamic functional assessment of the coronary vasculature is of utmost importance in clinical practice due to the fact that Cardiovascular Diseases have become the leading cause of death globally. In this work we propose a novel method that combines two of the most efficient methods of hemodynamic status assessment of coronary arteries, Intravascular UtraSound and virtual Functional Assessment Index, an index that correlates well to the measured Fractional Flow Reserve. One Left Anterior Descending segment was reconstructed both in a straight manner (using only IVUS images) as well as using the actual 3D geometry of the vessel (using IvUS images combined with the respective coronary angiographic images [2])...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226760/a-new-approach-of-oral-cancer-detection-using-bilateral-texture-features-in-digital-infrared-thermal-images
#13
M Chakraborty, S Mukhopadhyay, A Dasgupta, S Patsa, N Anjum, J G Ray, M Chakraborty, S Mukhopadhyay, A Dasgupta, S Patsa, N Anjum, J G Ray, S Patsa, A Dasgupta, N Anjum, M Chakraborty, S Mukhopadhyay, J G Ray
Oral cancer is one of the most prevalent form of cancer and its severity is aggrandized specially among the socio-economically backward population in developing countries. A major fraction of patient population is unable to avail diagnosis for oral cancer due to scarcity of state-of-the-art infrastructure and experienced oral and maxillofacial pathologist. Contemporary gold standard of oral cancer confirmation relies on biopsy report. But biopsy is invasive and thus patients are usually reluctant to undergo this test...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226694/multi-output-gaussian-processes-for-enhancing-resolution-of-diffusion-tensor-fields
#14
Hernan Dario Vargas Cardona, Alvaro A Orozco, Mauricio A Alvarez, Hernan Dario Vargas Cardona, Alvaro A Orozco, Mauricio A Alvarez, Hernan Dario Vargas Cardona, Mauricio A Alvarez, Alvaro A Orozco
Second order diffusion tensor (DT) fields are widely used in several clinical applications: brain fibers connections, diagnosis of neuro-degenerative diseases, image registration, brain conductivity models, etc. However, due to current acquisition protocols and hardware limitations in MRI machines, the diffusion magnetic resonance imaging (dMRI) data is obtained with low spatial resolution (1 or 2 mm(3) for each voxel). This issue can be significant, because tissue fibers are much smaller than voxel size. Interpolation has become in a successful methodology for enhancing spatial resolution of DT fields...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226538/sheathless-and-high-throughput-sorting-of-paramagnetic-microparticles-in-a-magneto-hydrodynamic-microfluidic-device
#15
Vikash Kumar, Pouya Rezai, Vikash Kumar, Pouya Rezai, Vikash Kumar, Pouya Rezai
Sorting of microorganisms and particles from a mixture is critical for numerous biotechnological and medical applications. Several sorting methods such as pinched flow fractionation (PFF), optical sorting, dielectrophoresis, acoustic separation, magnetophoresis and deterministic lateral displacement (DLD) have been reported in literature. But most of these methods lack ideal characteristics of a sorter such as ability to process at high throughput, simple design, non-complicated fabrication method, sheathless operation and high purity in separation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226465/in-silico-pre-clinical-trials-for-implantable-cardioverter-defibrillators
#16
Zhihao Jiang, Houssam Abbas, Kuk Jin Jang, Marco Beccani, Jackson Liang, Sanjay Dixit, Rahul Mangharam, Zhihao Jiang, Houssam Abbas, Kuk Jin Jang, Marco Beccani, Jackson Liang, Sanjay Dixit, Rahul Mangharam, Jackson Liang, Marco Beccani, Sanjay Dixit, Rahul Mangharam, Houssam Abbas, Zhihao Jiang, Kuk Jin Jang
Regulatory authorities require that the safety and efficacy of a new high-risk medical device be proven in a Clinical Trial (CT), in which the effects of the device on a group of patients are compared to the effects of the current standard of care. Phase III trials can run for several years, cost millions of dollars, and expose patients to an unproven device. In this paper, we demonstrate how to use a large group of synthetic patients based on computer modeling to improve the planning of a CT so as to increase the chances of a successful trial for implantable cardioverter defibrillators (ICDs)...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226448/graph-fractional-order-total-variation-eeg-source-reconstruction
#17
Ying Li, Jing Qin, Stanley Osher, Wentai Liu, Ying Li, Jing Qin, Stanley Osher, Wentai Liu, Jing Qin, Stanley Osher, Ying Li, Wentai Liu
EEG source imaging is able to reconstruct sources in the brain from scalp measurements with high temporal resolution. Due to the limited number of sensors, it is very challenging to locate the source accurately with high spatial resolution. Recently, several total variation (TV) based methods have been proposed to explore sparsity of the source spatial gradients, which is based on the assumption that the source is constant at each subregion. However, since the sources have more complex structures in practice, these methods have difficulty in recovering the current density variation and locating source peaks...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226412/rage-polymorphisms-and-oxidative-stress-levels-in-hashimoto-s-thyroiditis
#18
Maria Giannakou, Katerina Saltiki, Emily Mantzou, Eleni Loukari, Georgios Philippou, Konstantinos Terzidis, Kiriaki Lili, Charalampos Stavrianos, Miltiades Kyprianou, Maria Alevizaki
BACKGROUND: Polymorphisms of the receptor for advanced glycation end products (RAGE) gene have been studied in various autoimmune disorders, but not in Hashimoto's thyroiditis. Also, increased oxidative stress has been described in patients with Hashimoto's thyroiditis. The aim of the present study was to investigate the possible role of two common RAGE polymorphisms (-429T>C, -374T>A) in Hashimoto's thyroiditis; in parallel we studied oxidative stress levels. MATERIALS AND METHODS: 300 consecutive euthyroid women were examined and classified into three groups: Hashimoto's thyroiditis with treatment (n=96), Hashimoto's thyroiditis without treatment (n=109) and controls (n=95)...
February 22, 2017: European Journal of Clinical Investigation
https://www.readbyqxmd.com/read/28226311/effects-of-root-extracts-of-eurycoma-longifolia-jack-on-corpus-cavernosum-of-rat
#19
Bae Huey Tee, See Ziau Hoe, Swee Hung Cheah, Sau Kuen Lam
OBJECTIVE: This study was conducted to investigate the mechanisms of action of Eurycoma longifolia in rat corpus cavernosum. MATERIALS AND METHODS: Tincture of the roots was concentrated to dryness by evaporating the ethanol in vacuo. This ethanolic extract was partitioned into five fractions sequentially with hexane, dichloromethane, ethyl acetate, butanol and water. The corpus cavernosum relaxant activity of each fraction was investigated. Dichloromethanic (DCM) fraction which showed the highest potency in relaxing phenylephrine-precontracted corpora cavernosa was purified by column chromatography...
February 22, 2017: Medical Principles and Practice: International Journal of the Kuwait University, Health Science Centre
https://www.readbyqxmd.com/read/28226299/colorimetric-and-electrophoretic-evaluation-of-lipoprotein-fractions-in-healthy-neonatal-calves-comparison-with-results-from-adult-cows-and-from-calves-with-inflammatory-conditions
#20
Alessia Giordano, Gabriele Rossi, Monica Probo, Pierangelo Moretti, Saverio Paltrinieri
High density lipoproteins (HDLs) are pivotal in innate immunity and decrease in serum during inflammation. Several studies have been done about lipoprotein changes in transition cows but little is known about their changes in newborn calves. The aim of this study is to provide information about HDLs in newborn calves, by defining the possible age-related changes in healthy calves compared with adults and by assessing the possible differences in calves with inflammation. Lipoprotein electrophoretic separation (reported as percentages) and colorimetric measurement of HDL (HDL-C) were performed on healthy cows and calves in order to identify possible differences in the lipoprotein profile due to the age...
February 13, 2017: Research in Veterinary Science
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