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flow imaging

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https://www.readbyqxmd.com/read/28227867/knife-edge-scanning-microscopy-for-in-silico-study-of-cerebral-blood-flow-from-biological-imaging-data-to-flow-simulations
#1
Michael R Nowak, Alexander Lozovskiy, Dimitri Dobroskok, Yoonsuck Choe, Michael R Nowak, Alexander Lozovskiy, Dimitri Dobroskok, Yoonsuck Choe, Dimitri Dobroskok, Michael R Nowak, Alexander Lozovskiy, Yoonsuck Choe
Knife-edge scanning microscopy provides the capability to image whole-brain cerebral microvasculature of small organisms, such as mice, at sub-micron resolution, providing a feasible foundation for the reconstruction of circulatory pathways from the systemic to cellular scale. In this paper, we illustrate the feasibility of using this data to model cerebral blood flow using numerical simulations. Starting with a small vascular element in microcirculation of interest, we present its segmentation from the imaging-data volume, construction of its triangular surface mesh, assembly of its tetrahedral volumetric mesh from the surface, and then conclude with Stokes flow simulation of plasma through the microvascular vessel...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227866/modelling-nutrient-transfer-based-on-3d-imaging-of-the-human-placental-microstructure
#2
S Perazzolo, R M Lewis, B G Sengers, S Perazzolo, R M Lewis, B G Sengers, B G Sengers, R M Lewis, S Perazzolo
Impaired transfer of nutrients from mother to fetus can affect pregnancy outcomes. The placenta has a complex microstructure, including the maternal intervillous space and fetal capillaries. Previous computational models of placental transfer either assumed a simplified idealized local geometry or were based on 2D imaging. In this study, we present a novel 3D computational model to assess the placental transfer of nutrients at the microscale in interaction with the maternal flow environment. A stack of confocal microscopy images of the placental terminal villi was collected and reconstructed...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227671/imquant-an-image-based-fluorescence-reader-for-quantitative-lateral-flow-immunoassays
#3
Kaushik Basak Chowdhury, Jayaraj Joseph, Jayaraman Kiruthi Vasan, Mohanasankar Sivaprakasam, Kaushik Basak Chowdhury, Jayaraj Joseph, Jayaraman Kiruthi Vasan, Mohanasankar Sivaprakasam, Jayaraman Kiruthi Vasan, Mohanasankar Sivaprakasam, Jayaraj Joseph, Kaushik Basak Chowdhury
Fluorescence immunoassays (FIA) have strong potential in enabling rapid quantitative immunological testing at point of care. Existing state of the art instruments employ laser scanning of FIA test kits, which require the use of electromechanical systems, making the instrument bulky, heavy and less reliable in the long term. There is a growing need for an extremely compact and reliable, motion-free, automated reader for accurate quantification of immunoassays. Here, we present ImQuant, an image based FIA reader with integrated monochromatic excitation source, optical filtering and real time image capture, assisted with an intuitive graphical user interface...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227411/source-imaging-of-simple-finger-movements-captured-during-auditory-response-tasks-using-space-time-frequency-based-sparsity-constraints
#4
Aritra Chaudhuri, Aurobinda Routray, Aritra Chaudhuri, Aurobinda Routray, Aurobinda Routray, Aritra Chaudhuri
Neural Information Flow during simple cognitive or motor actions is a significant research topic; one of which is a simple finger movement. In this paper, Electro-encephalograph (EEG) Source Imaging has been used to model the Neural Information flow, during performance of a simple Auditory Response Task (ART), specifically by employment of a space-time-frequency sparsity constrained based algorithm, namely, Spatio-temporal Unifying Tomography (STOUT). The estimated sources are then studied according to location defined based on Destrieux atlas...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227375/motion-invariant-contrast-enhancement-of-optical-imaging-data-in-the-gradient-domain
#5
Philipp Flotho, Alejandro Romero-Santiago, Karsten Schwerdtfeger, Jacek Szczygielski, Matthias Hulser, Lars Haab, Daniel J Strauss, Philipp Flotho, Alejandro Romero-Santiago, Karsten Schwerdtfeger, Jacek Szczygielski, Matthias Hulser, Lars Haab, Daniel J Strauss, Daniel J Strauss, Alejandro Romero-Santiago, Jacek Szczygielski, Karsten Schwerdtfeger, Philipp Flotho, Lars Haab
Functional optical imaging (OI) of intrinsic signals (like blood oxygenation coupled reflection changes) and of extrinsic properties of voltage sensitive probes (like voltage-sensitive dyes (VSD)) forms a group of neuroimaging techniques that possess up to date highest temporal and spatial resolution on a meso-to macroscopic scale. An inherent problem of OI is a very low signal to noise ratio (SNR), which restricts the recordings to be completely motionless and requires detailed knowledge of the properties of the different noise sources...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227290/pre-clinical-investigations-of-multi-path-propagation-in-transcranial-doppler-ultrasound-flow-phantom
#6
Alexander J Weir, Cheng-Xiang Wang, Stuart Parks, Alexander J Weir, Cheng-Xiang Wang, Stuart Parks, Alexander J Weir, Stuart Parks, Cheng-Xiang Wang
There are various practical situations in medical applications when pre-clinical investigations must be performed using a simulation environment or test bench prior to human studies. One example is the analysis of propagation channels in Transcanial Doppler (TCD) ultrasound (US), a signal processing challenge requiring the analysis of data from US waves scattered in three dimensions (3D). When examining the effects of scatterers in such channels, it is common to use a data acquisition test bench and a Doppler flow phantom...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227283/a-method-to-detect-tortuosity-of-vessel-using-non-imaging-ultrasound-approach-in-carotid-structure
#7
Ravindra B Patil, P Krishnamoorthy, Ravindra B Patil, P Krishnamoorthy, Ravindra B Patil, P Krishnamoorthy
Stroke is a leading cause of functional impairments. The typical screening mechanism is to measure localized Peak Systolic Velocity (PSV) and diagnose impending risk associated with stoke by characterizing the PSV values. However, an accurate measurement of PSV using Doppler ultrasound is affected due to the tortuous nature of carotid artery in elder population group as the angle at which acoustic beam strikes the vessel is over or under estimated resulting in improper measure the blood flow velocity. Hence, the proposed approach estimates the degree of tortuosity of the carotid vessel and includes this as calibration parameter to compute an accurate PSV...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227126/cardiac-muscle-energetics-improved-normalisation-of-heat-using-optical-coherence-tomography
#8
Ming L Cheuk, Callum M Johnston, June-Chiew Han, Denis S Loiselle, Poul M F Nielsen, Andrew J Taberner, Ming L Cheuk, Callum M Johnston, June-Chiew Han, Denis S Loiselle, Poul M F Nielsen, Andrew J Taberner, June-Chiew Han, Callum M Johnston, Poul M F Nielsen, Ming L Cheuk, Denis S Loiselle, Andrew J Taberner
Heat liberated from isolated cardiac muscle has been used to inform us of thermo-mechanical processes that occur during a contraction. However, for comparisons between different samples to be useful, the heat output needs to be normalized to volume. We have implemented an optical coherence tomograph (OCT), together with a flow-through calorimeter, to accurately determine both muscle volume and heat in the same measurement chamber. The heat rate for multiple stimulation frequencies were recorded and normalized to the volume captured by the OCT...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227078/real-time-respiration-rate-measurement-from-thoracoabdominal-movement-with-a-consumer-grade-camera
#9
Avishek Chatterjee, A P Prathosh, Pragathi Praveena, Avishek Chatterjee, A P Prathosh, Pragathi Praveena, Avishek Chatterjee, A P Prathosh, Pragathi Praveena
In this paper, we propose a novel computer vision technique to measure respiration rate by counting the periodic thoracoabdominal motion in real-time using an inexpensive consumer grade camera. We compute the component of optical flow parallel to the image gradient at each pixel, which is a computationally inexpensive operation. Then, we find a principal flow field by gathering information over many frames. Subsequently, in each frame, we compute the component of flow along this principal flow field to capture the thoracoabdominal motion...
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
#10
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/28226983/perspective-imaging-of-flow-in-arterial-model-obtained-with-continuous-wave-doppler-focusing-technique
#11
Ryo Nagaoka, Katsuhiro Sasaki, Seiichi Zama, Masaaki Nagone, Hiroshi Nagai, Yasuhito Takeuchi, Yoshifumi Saijo, Ryo Nagaoka, Katsuhiro Sasaki, Seiichi Zama, Masaaki Nagone, Hiroshi Nagai, Yasuhito Takeuchi, Yoshifumi Saijo, Yoshifumi Saijo, Hiroshi Nagai, Katsuhiro Sasaki, Masaaki Nagone, Seiichi Zama, Ryo Nagaoka, Yasuhito Takeuchi
Flowing emboli in the circulatory system cause fatal diseases such as stroke or pulmonary embolism. Conventional transcranial Doppler ultrasound for detection of emboli requires precise positioning by experienced examiner. In the present study, an easier emboli detection device by visualizing perspective view of blood vessel is proposed. The perspective image was obtained with continuous wave (CW) Doppler ultrasound from 2-dimensional array probe. CW Doppler signal from each element was focused by novel beam forming algorithm to obtain en face images at arbitrary depth to form perspective image...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226737/4d-lung-tumor-segmentation-via-shape-prior-and-motion-cues
#12
Jung Won Cha, Mohammad M Farhangi, Neal Dunlap, Amir Amini, Jung Won Cha, Mohammad M Farhangi, Neal Dunlap, Amir Amini, Jung Won Cha, Amir Amini, Neal Dunlap, Mohammad M Farhangi
Lung tumor segmentation is important for therapy in the radiation treatment of patients with thoracic malignancies. In this paper, we describe a 4D image segmentation method based on graph-cuts optimization, shape prior and optical flow. Due to small size, the location, and low contrast between the tumor and the surrounding tissue, tumor segmentation in 3D+t is challenging. We performed 4D lung tumor segmentation in 5 patients, and in each case compared the results with the expert-delineated lung nodules. In each case, 4D image segmentation took approximately ten minutes on a PC with AMD Phenom II and 32GB of memory for segmenting tumor in five phases of lung CT data...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226727/surgical-fiducial-segmentation-and-tracking-for-pose-estimation-based-on-ultrasound-b-mode-images
#13
Lei Chen, Nathanael Kuo, Fereshteh Aalamifar, David Narrow, Devin Coon, Jerry Prince, Emad M Boctor, Lei Chen, Nathanael Kuo, Fereshteh Aalamifar, David Narrow, Devin Coon, Jerry Prince, Emad M Boctor, David Narrow, Emad M Boctor, Devin Coon, Lei Chen, Jerry Prince, Nathanael Kuo, Fereshteh Aalamifar
Doppler ultrasound is a non-invasive diagnostic tool for the quantitative measurement of blood flow. However, given that it provides velocity data that is dependent on the location and angle of measurement, repeat measurements to detect problems over time may require an expert to return to the same location. We therefore developed an image-guidance system based on ultrasound B-mode images that enables an inexperienced user to position the ultrasound probe at the same site repeatedly in order to acquire a comparable time series of Doppler readings...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226725/a-chicken-embryo-cardiac-outflow-tract-atlas-for-registering-changes-due-to-abnormal-blood-flow
#14
James P Carson, Monique Y Rennie, Michael Danilchik, Kent Thornburg, Sandra Rugonyi, James P Carson, Monique Y Rennie, Michael Danilchik, Kent Thornburg, Sandra Rugonyi, Kent Thornburg, Michael Danilchik, James P Carson, Monique Y Rennie, Sandra Rugonyi
Subdivision-based image registration has previously been applied to co-localize digital information extracted from rigid structures in biological specimens, such as the brain. Here, we describe and demonstrate the creation and application of a two-dimensional subdivision-based atlas representing a dynamic structure: the outflow tract of the developing chicken heart. The atlas is designed to segment three different anatomical layers of the outflow tract, and is demonstrated on the characterization of collagen XIV in both control and induced abnormal flow specimens...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226721/overcoming-spatio-temporal-limitations-using-dynamically-scaled-in-vitro-pc-mri-a-flow-field-comparison-to-true-scale-computer-simulations-of-idealized-stented-and-patient-specific-left-main-bifurcations
#15
Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan, Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan, Stuart Norris, Brett Cowan, Pau Medrano-Gracia, Kathleen Gilbert, Mark Webster, Alistair Young, Susann Beier, John Cater, John Ormiston
The majority of patients with angina or heart failure have coronary artery disease. Left main bifurcations are particularly susceptible to pathological narrowing. Flow is a major factor of atheroma development, but limitations in imaging technology such as spatio-temporal resolution, signal-to-noise ratio (SNRv), and imaging artefacts prevent in vivo investigations. Computational fluid dynamics (CFD) modelling is a common numerical approach to study flow, but it requires a cautious and rigorous application for meaningful results...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226696/divergence-map-from-diffusion-tensor-imaging-concepts-and-application-to-corpus-callosum
#16
Gustavo R Pinheiro, Guilherme S Soares, Andre Luis Costa, Roberto A Lotufo, Leticia Rittner, Gustavo R Pinheiro, Guilherme S Soares, Andre Luis Costa, Roberto A Lotufo, Leticia Rittner, Leticia Rittner, Gustavo R Pinheiro, Roberto A Lotufo, Andre Luis Costa, Guilherme S Soares
This work proposes a novel approach to the analysis of Diffusion Tensor Imaging (DTI) by applying the mathematical concept of divergence, used in vector analysis. This is achieved by choosing an arbitrary direction of analysis and using this direction to transform the diffusion tensor field into an oriented vector field. The method was inspired by the idea of imposing a liquid flow inside the biological tissues, oriented in the direction of analysis, and watching the direction it would be expected to take as it flows through the paths created by the fibers...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226688/mitral-valve-annulus-localization-in-3d-echocardiography
#17
Abhishek Tiwari, Kedar A Patwardhan, Abhishek Tiwari, Kedar A Patwardhan, Kedar A Patwardhan, Abhishek Tiwari
The Mitral Valve is a structure on the left side of the human heart that regulates the flow of oxygenated blood into the Left Ventricle and also helps maintain the pressure within the Left Ventricle when the blood gets pumped to the rest of the body from the Left Ventricle. Pathology of the Mitral Valve often manifests through structural changes in the anatomy. Assessment of Mitral Valve pathology as well as determination of specific interventions require quantification of various structures of the Mitral Valve and one of these structures of interest is the Mitral Valve annulus...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226680/fast-scale-invariant-lateral-lumbar-vertebrae-detection-and-segmentation-in-x-ray-images
#18
Ruhan Sa, William Owens, Raymond Wiegand, Vipin Chaudhary, Ruhan Sa, William Owens, Raymond Wiegand, Vipin Chaudhary, William Owens, Ruhan Sa, Raymond Wiegand, Vipin Chaudhary
Fully automatic localization of lumbar vertebrae from clinical X-ray images is very challenging due to the variation of X-ray quality, scale, contrast, number of visible vertebrae, etc. To overcome these challenges, we present a novel framework, where we accelerate a scale-invariant object detection method using Support Vector Machines (SVM) trained on Histogram of Oriented Gradients (HOG) features and segmenting a fine vertebra contour using Gradient Vector Flow (GVF) based snake model. Support Vector Machines trained on HOG features are now an object detection standard in many perception fields and have demonstrated good performance on medical images as well...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226524/robust-estimation-of-simulated-urinary-volume-from-camera-images-under-bathroom-illumination
#19
Chizuru Honda, Md Shoaib Bhuiyan, Haruki Kawanaka, Eiichi Watanabe, Koji Oguri, Chizuru Honda, Md Shoaib Bhuiyan, Haruki Kawanaka, Eiichi Watanabe, Koji Oguri, Eiichi Watanabe, Haruki Kawanaka, Chizuru Honda, Koji Oguri, Md Shoaib Bhuiyan
General uroflowmetry method involves the risk of nosocomial infections or time and effort of the recording. Medical institutions, therefore, need to measure voided volume simply and hygienically. Multiple cylindrical model that can estimate the fluid flow rate from the photographed image using camera has been proposed in an earlier study. This study implemented a flow rate estimation by using a general-purpose camera system (Raspberry Pi Camera Module) and the multiple cylindrical model. However, large amounts of noise in extracting liquid region are generated by the variation of the illumination when performing measurements in the bathroom...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226476/ultrasound-characterization-of-interface-oscillation-as-a-proxy-for-ventriculoperitoneal-shunt-function
#20
April Joy C Aralar, Matthew D Bird, Robert D Graham, Beomseo Koo, Mahesh B Shenai, Parag V Chitnis, Siddhartha Sikdar, April Joy C Aralar, Matthew D Bird, Robert D Graham, Beomseo Koo, Mahesh B Shenai, Parag V Chitnis, Siddhartha Sikdar, Mahesh B Shenai, Beomseo Koo, Robert D Graham, Matthew D Bird, Siddhartha Sikdar, Parag V Chitnis, April Joy C Aralar
Hydrocephalus, where cerebrospinal fluid (CSF) production rate is greater than reabsorption rate, leads to impaired neurological function if left untreated. Ventriculoperitoneal shunts (VPS) are implanted in the brain ventricles to route CSF. VPS systems have a high failure rate, and failure symptoms resemble symptoms of common maladies. The current gold standard for shunt diagnosis, surgical intervention, poses high risk and requires an expensive procedure for patients. Current non-invasive methods lack proper insight to assist physicians...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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