Automated Three-Dimensional Reconstruction of the Left Ventricle From Multiple-Axis Echocardiography

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Navaneetha Krishnan Rajan ◽  
Zeying Song ◽  
Kenneth R. Hoffmann ◽  
Marek Belohlavek ◽  
Eileen M. McMahon ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Cross Sections ◽  
Low Cost ◽  
Software Tool ◽  
Acquisition Time ◽  
Lv Function ◽  
High Temporal Resolution ◽  
Standard Format ◽  
Flow Simulations ◽  
Automated Method

Two-dimensional echocardiography (echo) is the method of choice for noninvasive evaluation of the left ventricle (LV) function owing to its low cost, fast acquisition time, and high temporal resolution. However, it only provides the LV boundaries in discrete 2D planes, and the 3D LV geometry needs to be reconstructed from those planes to quantify LV wall motion, acceleration, and strain, or to carry out flow simulations. An automated method is developed for the reconstruction of the 3D LV endocardial surface using echo from a few standard cross sections, in contrast with the previous work that has used a series of 2D scans in a linear or rotational manner for 3D reconstruction. The concept is based on a generalized approach so that the number or type (long-axis (LA) or short-axis (SA)) of sectional data is not constrained. The location of the cross sections is optimized to minimize the difference between the reconstructed and measured cross sections, and the reconstructed LV surface is meshed in a standard format. Temporal smoothing is implemented to smooth the motion of the LV and the flow rate. This software tool can be used with existing clinical 2D echo systems to reconstruct the 3D LV geometry and motion to quantify the regional akinesis/dyskinesis, 3D strain, acceleration, and velocities, or to be used in ventricular flow simulations.

3D Reconstruction of the Left Ventricle From Four Echocardiographic Projections

2014 ◽  
Author(s):  
Navaneetha Krishnan Rajan ◽  
Zeying Song ◽  
Kenneth R. Hoffmann ◽  
Marek Belohlavek ◽  
Eileen M. McMahon ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Three Dimensional ◽  
Image Data ◽  
Left Ventricular ◽  
The Body ◽  
Patient Specific ◽  
Immersed Boundary ◽  
Cross Sectional ◽  
Standard Format ◽  
Automated Method

The left ventricle (LV) of a human heart receives oxygenated blood from the lungs and pumps it throughout the body via the aortic valve. Characterizing the LV geometry, its motion, and the ventricular flow is critical in assessing the heart’s health. An automated method has been developed in this work to generate a three-dimensional (3D) model of the LV from multiple-axis echocardiography (echo). Image data from three long-axis sections and a basal section is processed to compute spatial nodes on the LV surface. The generated surfaces are output in a standard format such that it can be imported into the curvilinear-immersed boundary (CURVIB) framework for numerical simulation of the flow inside the LV. The 3D LV model can be used for better understanding of the ventricular motion and the simulation framework provides a powerful tool for studying left ventricular flows on a patient specific basis. Future work would incorporate data from additional cross-sectional images.

scholarly journals Myocardial deformation in patients with a single left ventricle using 2D cardiovascular magnetic resonance feature tracking: a case–control study

2021 ◽  
Author(s):  
Fabian Strodka ◽  
Jana Logoteta ◽  
Roman Schuwerk ◽  
Mona Salehi Ravesh ◽  
Dominik Daniel Gabbert ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Ventricle ◽  
Feature Tracking ◽  
Systolic Function ◽  
Radial Strain ◽  
Left Ventricular ◽  
Lv Function ◽  
Significant Difference ◽  
Lv Volumes

AbstractVentricular dysfunction is a well-known complication in single ventricle patients in Fontan circulation. As studies exclusively examining patients with a single left ventricle (SLV) are sparse, we assessed left ventricular (LV) function in SLV patients by using 2D-cardiovascular magnetic resonance (CMR) feature tracking (2D-CMR-FT) and 2D-speckle tracking echocardiography (2D-STE). 54 SLV patients (11.4, 3.1–38.1 years) and 35 age-matched controls (12.3, 6.3–25.8 years) were included. LV global longitudinal, circumferential and radial strain (GLS, GCS, GRS) and strain rate (GLSR, GCSR, GRSR) were measured using 2D-CMR-FT. LV volumes, ejection fraction (LVEF) and mass were determined from short axis images. 2D-STE was applied in patients to measure peak systolic GLS and GLSR. In a subgroup analysis, we compared double inlet left ventricle (DILV) with tricuspid atresia (TA) patients. The population consisted of 19 DILV patients, 24 TA patients and 11 patients with diverse diagnoses. 52 patients were in NYHA class I and 2 patients were in class II. Most SLV patients had a normal systolic function but median LVEF in patients was lower compared to controls (55.6% vs. 61.2%, p = 0.0001). 2D-CMR-FT demonstrated reduced GLS, GCS and GCSR values in patients compared to controls. LVEF correlated with GS values in patients (p < 0.05). There was no significant difference between GLS values from 2D-CMR-FT and 2D-STE in the patient group. LVEF, LV volumes, GS and GSR (from 2D-CMR-FT) were not significantly different between DILV and TA patients. Although most SLV patients had a preserved EF derived by CMR, our results suggest that, LV deformation and function may behave differently in SLV patients compared to healthy subjects.

scholarly journals Corrosion Study on Wellbore Materials for the CO2 Injection Process

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 115
Author(s):  
Le Quynh Hoa ◽  
Ralph Bäßler ◽  
Dirk Bettge ◽  
Enrico Buggisch ◽  
Bernadette Nicole Schiller ◽  
...  
Keyword(s):  
Cross Sections ◽  
Low Cost ◽  
Co2 Injection ◽  
Uniform Corrosion ◽  
Injection Wells ◽  
Safety Issues ◽  
Carbonation Process ◽  
Injection Process ◽  
Materials Used ◽  
Low Alloyed Steel

For reliability and safety issues of injection wells, corrosion resistance of materials used needs to be determined. Herein, representative low-cost materials, including carbon steel X70/1.8977 and low alloyed steel 1.7225, were embedded in mortar to mimic the realistic casing-mortar interface. Two types of cement were investigated: (1) Dyckerhoff Variodur commercial Portland cement, representing a highly acidic resistant cement and (2) Wollastonite, which can react with CO2 and become stable under a CO2 stream due to the carbonation process. Exposure tests were performed under 10 MPa and at 333 K in artificial aquifer fluid for up to 20 weeks, revealing crevice corrosion and uniform corrosion instead of expected pitting corrosion. To clarify the role of cement, simulated pore water was made by dispersing cement powder in aquifer fluid and used as a solution to expose steels. Surface analysis, accompanied by element mapping on exposed specimens and their cross-sections, was carried out to trace the chloride intrusion and corrosion process that followed.

Nonlinear-Time-Dependent Analysis of Micro Via-In-Pad Substrates for Solder Bumped Flip Chip Applications

2002 ◽  
Vol 124 (3) ◽  
pp. 205-211 ◽  
Author(s):  
John H. Lau ◽  
S. W. Ricky Lee ◽  
Stephen H. Pan ◽  
Chris Chang
Keyword(s):  
Cross Sections ◽  
Flip Chip ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Circuit Board ◽  
Test Results ◽  
Pcb Assembly ◽  
Creep Analysis ◽  
Chip Scale Package ◽  
Time Dependent Analysis

An elasto-plastic-creep analysis of a low-cost micro via-in-pad (VIP) substrate for supporting a solder bumped flip chip in a chip scale package (CSP) format which is soldered onto a printed circuit board (PCB) is presented in this study. Emphasis is placed on the design, materials, and reliability of the micro VIP substrate and of the micro VIP CSP solder joints on PCB. The solder is assumed to obey Norton’s creep law. Cross-sections of samples are examined for a better understanding of the solder bump, CSP substrate redistribution, micro VIP, and solder joint. Also, the thermal cycling test results of the micro VIP CSP PCB assembly is presented.

scholarly journals Study of the Readability of Passive UHF RFID Tags Placed Inside a Cargo Van by a Reader Located Outside

2014 ◽  
Vol 10 (2) ◽  
pp. 76
Author(s):  
Philippe Mariage ◽  
M.M. Handeme Nguema ◽  
Laurent Clavier
Keyword(s):  
Low Cost ◽  
Software Tool ◽  
Antenna System ◽  
Uhf Rfid ◽  
Passive Uhf Rfid ◽  
Passive Tags ◽  
Whole Space ◽  
Storage Area ◽  
Semi Empirical ◽  
Theoretical Results

The aim of this paper is to study the feasibility of getting information from a cargo van returning back on its storage area by using a low cost communication system. According to the low speed of the vehicle and to the involved short distances, a UHF RFID solution is considered. An experimental study shows that passive tags may be read successfully but not in the entire space of the van. A semi-empirical numerical method based on the Geometrical Optics is derived in order to build a fast computer aided-positioning tool that may help to optimize the location of the tags. The same software tool is used for carrying out a parametric study that informs on the best antenna system to use. It is find out that a solution using passive tags and two antennas limits the theoretical results to 90% successful reading percentage whereas using semi-passive tags ensures a 100% one in the whole space of the vehicle.

Using existing site surveillance cameras to automatically measure the installation speed in prefabricated timber construction

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Alireza Ahmadian Fard Fini ◽  
Mojtaba Maghrebi ◽  
Perry John Forsythe ◽  
Travis Steven Waller
Keyword(s):  
Time Window ◽  
Low Cost ◽  
Transformation Method ◽  
Digital Design ◽  
Spatial Transformation ◽  
Exact Matching ◽  
Productivity Measurement ◽  
Content Type ◽  
Surveillance Camera ◽  
Automated Method

PurposeMeasuring onsite productivity has been a substance of debate in the construction industry, mainly due to concerns about accuracy, repeatability and unbiasedness. Such characteristics are central to demonstrate construction speed that can be achieved through adopting new prefabricated systems. Existing productivity measurement methods, however, cannot cost-effectively provide solid and replicable evidence of prefabrication benefits. This research proposes a low-cost automated method for measuring onsite installation productivity of prefabricated systems.Design/methodology/approachFirstly, the captured ultra-wide footages are undistorted by extracting the curvature contours and performing a developed meta-heuristic algorithm to straighten these contours. Then a preprocessing algorithm is developed that could automatically detect and remove the noises caused by vibrations and movements. Because this study aims to accurately measure the productivity the noise free images are double checked in a specific time window to make sure that even a tiny error, which have not been detected in the previous steps, will not been amplified through the process. In the next step, the existing side view provided by the camera is converted to a top view by using a spatial transformation method. Finally, the processed images are compared with the site drawings in order to detect the construction process over time and report the measured productivity.FindingsThe developed algorithms perform nearly real-time productivity computations through exact matching of actual installation process and digital design layout. The accuracy and noninterpretive use of the proposed method is demonstrated in construction of a multistorey cross-laminated timber building.Originality/valueThis study uses footages of an already installed surveillance camera where the camera's features are unknown and then image processing algorithms are deployed to retrieve accurate installation quantities and cycle times. The algorithms are almost generalized and versatile to be adjusted to measure installation productivity of other prefabricated building systems.

Development of a hydraulic driven bionic soft gecko toe

2021 ◽  
pp. 1-18
Author(s):  
Mingyue Lu ◽  
Guangming Chen ◽  
Qingsong He ◽  
Weijia Zong ◽  
Zhiwei Yu ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Low Cost ◽  
Hydraulic Pressure ◽  
Curved Surfaces ◽  
Type B ◽  
Surface Conditions ◽  
Flat Surfaces ◽  
Soft Actuator ◽  
Output Force

Abstract Geckos can climb freely on various types of surfaces using their flexible and adhesive toes. Gecko-inspired robots are capable of climbing on different surface conditions and have shown many important applications. Nonetheless, due to poor flexibility of toes the movements of gecko-inspired robots are restricted to flat surfaces. To improve the flexibility, by utilizing design technique of soft actuator and incorporating the characteristics of a real gecko's toe, the design of new bionic soft toes is proposed. The abilities of this bionic toe are verified using modelling and two soft toes are manufactured. One is Type A toe having varied semi-circle cross-sections as the feature of real gecko toe and the other is Type B toe with a constant semi-circle cross-section. The bending behaviors of the bionic toes subjected to a range of hydraulic pressure are also experimentally studied. It demonstrated that both toes can perform similarly large bending angles for the adduction (attachment) and abduction (detachment) motions. In comparisons, Type B toe exhibits larger output force, which is ascribed to the fact that at proximal section of Type B corresponds to larger volume for bearing fluid. Both toes can not only provide sufficient adhesion, but can be quickly detached with low peeling forces. Finally, different curved surfaces are used to further justify the applicability of these bionic toes. In particular, the flexible toes developed also have the advantages of low cost, lightweight, and simple control, which is desirable for wall-climbing robots.

scholarly journals The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2

2001 ◽  
Vol 19 (6) ◽  
pp. 593-600 ◽  
Author(s):  
O. Norberg ◽  
J. D. Winningham ◽  
H. Lauche ◽  
W. Keith ◽  
W. Puccio ◽  
...  
Keyword(s):  
Technological Development ◽  
Low Cost ◽  
Local Magnetic Field ◽  
High Temporal Resolution ◽  
Two Dimensional ◽  
Spin Plane ◽  
Low Mass ◽  
Instruments And Techniques ◽  
Auroral Emissions ◽  
Auroral Phenomena

Abstract. The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two "top-hat"-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second) allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA is mounted with its aperture close to the spin plane of Astrid-2, which allows for good pitch-angle coverage when the local magnetic field is in the satellite spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral emissions. Using the spacecraft spin and orbital motion, it is possible to create two-dimensional images from the data. Spin-scanning photometers, such as PIA, are low-cost, low mass alternatives to auroral imagers, but place constraints on the satellite attitude. Data from MEDUSA are used to study processes in the auroral region, in particular, electrodynamics of aurora and "black aurora". MEDUSA is also a technological development, paving the way for highly capable, miniaturized particle spectrometers.Key words. Ionosphere (instruments and techniques) – Magnetospheric physics (auroral phenomena; instruments and techniques)

scholarly journals Advances in Conjugated Polymer Lasers

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 443 ◽  
Author(s):  
Hongyan Xia ◽  
Chang Hu ◽  
Tingkuo Chen ◽  
Dan Hu ◽  
Muru Zhang ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Cross Sections ◽  
Conjugated Polymer ◽  
Low Cost ◽  
Research Direction ◽  
Stimulated Emission ◽  
Laser Materials ◽  
Radiation Mechanism ◽  
The Subject ◽  
Low Cost Manufacturing

This paper provides a review of advances in conjugated polymer lasers. High photoluminescence efficiencies and large stimulated emission cross-sections coupled with wavelength tunability and low-cost manufacturing processes make conjugated polymers ideal laser gain materials. In recent years, conjugated polymer lasers have become an attractive research direction in the field of organic lasers and numerous breakthroughs based on conjugated polymer lasers have been made in the last decade. This paper summarizes the recent progress of the subject of laser processes employing conjugated polymers, with a focus on the photoluminescence principle and excitation radiation mechanism of conjugated polymers. Furthermore, the effect of conjugated polymer structures on the laser threshold is discussed. The most common polymer laser materials are also introduced in detail. Apart from photo-pumped conjugated polymer lasers, a direction for the future development of electro-pumped conjugated polymer lasers is proposed.

scholarly journals Optimization of flat-oval pipes and perspectives of their application in beam structures

2018 ◽  
Vol 251 ◽  
pp. 03016
Author(s):  
Alexander Marutyan ◽  
Tamazi Kobaliya ◽  
Evgeny Galdin
Keyword(s):  
Cross Sections ◽  
Bending Strength ◽  
Low Cost ◽  
Design Parameters ◽  
Technical Solution ◽  
Optimal Parameters ◽  
Resistance Moment ◽  
Thin Walled ◽  
Lower Height ◽  
Oval Shape

A new technical solution for re-profiling round tubes into flat-oval ones with a ratio of 1 / 3,064 is presented, which increases their bending strength. The calculation of the optimal parameters of thin-walled sections of the flat-oval shape is given by an approximate method, the correctness of which is confirmed by testing from the standard profiles used. This calculation is repeated with respect to thin-walled sections of the oval shape. The whole diagram of changes in the design parameters of flat-oval and oval pipes is presented in the transformation of their cross-sections from vertical configurations to horizontal ones, including the transition through the outline of a circular shape. The comparative analysis of optimized cross sections of flat oval, oval and round tubes is carried out taking into account the elastic and elastic-plastic deformations of the structural material, where the length of the midline of the thin-walled section is taken as the dividing line between these deformations. The choice is substantiated in favour of flat-oval profile pipes due to their simpler shape including faces of constant curvature (flat and semi-circular), relatively low cost, lower height, greater compactness, higher resistance moment.

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