Quantification Of Deformation Research Articles

OP.8D.05] LAYER-SPECIFIC QUANTIFICATION OF MYOCARDIAL DEFORMATION MAY DISCLOSE THE SUBCLINICAL SYSTOLIC DYSFUNCTION AND THE MECHANISM OF RESERVED EJECTION FRACTION IN HYPERTENSIVE PATIENTS

Objective: Hypertension (HTN) leads to left ventricular (LV) remodeling, which results in diastolic dysfunction in the presence of preserved ejection fraction (EF). The goal of this study was to explore the subclinical left ventricular systolic dysfunction and the mechanism of preserved EF using layer-specific quantification of myocardial deformation in patients with HTN. Design and method: The routine 2D (frame rate > 50 Hz) data sets were acquired using GE E9 system in 120 hypertensive patients (73 male, 54 ± 13years, blood pressure =165 ± 20/ 96 ± 16 mmHg) and 120 age and gender matched normal subjects (124 ± 9/80 ± 8mmHg). The relative wall thickness (RWT) was calculated as the sum of anterior septal and posterior wall thickness divided by the LV end-diastolic dimension. Analysis of 2D strain was performed by EchoPac software. The RWT, LV mass index, and EF, as well as the values of 2D LV global and layer longitudinal and circumferential strains were all analyzed. Results: The LVEF was normal in all HTN patients. The RWT and LV mass index were higher in HTN than normal group (0.40 ± 0.07 vs 0.35 ± 0.03, p < 0.0001; 91 ± 26 vs 84 ± 8 g/m2, p < 0.0001). The absolute value of layer and global longitudinal strain was significantly decreased (−24 ± 3vs −26 ± 3 %, p < 0.0001;. −21 ± 3vs −23 ± 3%, respectively, p < 0.0001) and global circumferential strain (−40 ± 6vs −35 ± 5 %, −31 ± 7 vs −27 ± 4 % respectively, p < 0.0001), and the LV twist (23 ± 5 vs 18 ± 6 degree, p < 0.0001) were higher in HTN group than in normals. Conclusions: This study revealed that hypertension results in increased RWT and LV mass. The absolute value of layer and global longitudinal strain was significantly decreased in HTN patients than control group, which may implicate the early systolic dysfunction due to the endomyocardium function impaired. The absolute value of circumferential strain, and LV twist were significantly increased, which may be a compensatory mechanism to maintain LVEF.

Nonlinear deformation and localized failure of bacterial streamers in creeping flows.

We investigate the failure of bacterial floc mediated streamers in a microfluidic device in a creeping flow regime using both experimental observations and analytical modeling. The quantification of streamer deformation and failure behavior is possible due to the use of 200 nm fluorescent polystyrene beads which firmly embed in the extracellular polymeric substance (EPS) and act as tracers. The streamers, which form soon after the commencement of flow begin to deviate from an apparently quiescent fully formed state in spite of steady background flow and limited mass accretion indicating significant mechanical nonlinearity. This nonlinear behavior shows distinct phases of deformation with mutually different characteristic times and comes to an end with a distinct localized failure of the streamer far from the walls. We investigate this deformation and failure behavior for two separate bacterial strains and develop a simplified but nonlinear analytical model describing the experimentally observed instability phenomena assuming a necking route to instability. Our model leads to a power law relation between the critical strain at failure and the fluid velocity scale exhibiting excellent qualitative and quantitative agreeing with the experimental rupture behavior.

Quantification of spinal deformities using combined SCP and geometric 3D reconstruction

Abstract Three dimensional reconstruction is essential in accurate diagnosis of numerous spinal deformities which are 3D in nature. The stereo-radiographic reconstruction involving bi-planar X-rays is one of the most commonly used methods. Algorithms with stereo-corresponding point (SCP) or non-stereo-corresponding point (NSCP) can be used to achieve this 3D reconstruction. But, the NSCP method is slower and needs manual identification of many anatomical landmarks. Hence it suffers from observer variability and has restricted usage in normal clinical setup. Thus, a hybrid method is proposed in which the SCP reconstructed model is refined using the geometric features from the X-rays to achieve the accuracy closest to NSCP method. The SCP model is constructed using the X-rays on a calibration bench from the scoliotic subject. From these X-rays the vertebral features are extracted automatically. The SCP model structure is refined using the geometric transformations according to the extracted features. The 3D model thus formed is called combined SCP and geometric (CSCPG) reconstruction. By considering the NSCP model as a reference, both qualitative and quantitative approaches are followed to validate the proposed model. The CSCPG method has lesser observer variability as it needs only six anatomical landmarks per vertebra. Further, it is faster and the reconstruction error is within the acceptable limits. To quantify the deformities like axial vertebral rotation and spinal curvature novel methods have been proposed. The axial vertebral rotation is measured using simple vertebra vector parametric computations. It needs identification of only two landmarks per vertebra for angle measurement. The apical vertebra gives the plane of maximum curvature. The actual spinal curvature has to be computed on this plane. A semi-automatic method is proposed to compute this curvature using a new projection technique. The deformity quantification methods are validated using manual measurements as well as the results from standard approaches. Hence, a fast, simple and economic 3D diagnostic method is developed for quantification of the spinal deformities.

Kinematic evolution and quantification of deformation in external orogenic zones: a case study from the Tunisian Atlas

Abstract The quantification of deformation is one of the main objectives studied by geologists in order to control the evolution of tectonic structures and their kinematics during different tectonic phases. One of the most reliable methods of this theme is the direct calculation of quantity of deformation based on field data, while respecting several parameters such as the notion of tectonic inheritance and reactivation of pre-existing faults, or the relationship between the elongation and shortening axis with major faults. Thus, such a quantification of deformation in an area may explain the relations of thin- and thick-skinned tectonics during this deformation. The study of structural evolution of the Jebel Elkebar domain in the southern-central Tunisian Atlas permits us to quantify the deformation during the extensional phase by a direct calculation of the vertical throw along normal faults. This approach is verified by calculation of thickness of eroded strata in the uplifted compartment and of resedimented series, named the Kebar Formation, in the downthrown compartment. The obtained results confirm the importance of the Aptian-Albian extensional tectonic regime. The extent of deformation during the compressional phase, related to reactivation of pre-existing faults, is less than that of extensional phases; indeed the compressive reactivation did not compensate the vertical throw of normal faults. The geometry of the Elkebar fold is interpreted in terms of the “fault-related fold” model with a décollement level in the Triassic series. This permitted the partition of deformation between the basement and cover, so that the basement was allowed for a limited transport only, and the maximum of observed deformation was concentrated in the thin-skinned tectonics.

Layer-specific quantification of myocardial deformation may disclose the subclinical systolic dysfunction and the mechanism of preserved ejection fraction in patients with hypertension

BackgroundSystemic hypertension (HTN) leads to left ventricular (LV) remodeling, which results in diastolic dysfunction in the presence of preserved ejection fraction (EF). The goal of this study was to explore subclinical LV systolic dysfunction and the mechanism of preserved EF using layer-specific quantification of myocardial deformation in HTN patients. MethodsOne hundred and twenty HTN patients (mean blood pressure (BP) 165±20/ 96±16mmHg) and 120 age and gender matched volunteers (mean BP 120±10/76±8mmHg) were studied. Left ventricular echocardiographic parameters including LV ejection fraction (LVEF), global and regional peak longitudinal, circumferential 2D systolic layer strain and LV twist were measured. The associations between these parameters were studied against LV relative wall thickness (RWT) and LV mass index. ResultsLVEF was normal in all HTN patients. The RWT and LV mass index were higher in HTN group (0.40±0.06 vs 0.35±0.03, p<0.0001; 84±24 vs 63±11g/m2, p<0.0001). The absolute value of layer and global longitudinal strain was significantly lower in HTN group (−24±3 vs −26±3%, p<0.0001;. 21±3 vs −23±3%, p<0.0001, respectively). Global circumferential strain (−40±6 vs −35±5%, −31±7 vs −27±4% respectively, p<0.0001), and the LV twist (23±5 vs 18±6 degree, p<0.0001) were higher in HTN group. ConclusionsThis study revealed that hypertension resulted in increased RWT and LV mass. Impairment in layer and global longitudinal strain found in HTN patients may indicate early systolic dysfunction due to impaired endomyocardial function. Enhancement of circumferential strain and LV twist may be a compensatory mechanism to maintain LVEF in these patients.

Performance evaluation of warping characteristic of fused deposition modelling process

In recent years, fused deposition modelling (FDM) is gaining more popularity due to its distinct advantages in terms of cost-effectiveness, lower build times, and flexibility. Compared to other 3-D printing processes such as SLS, this process does not use any kind of high-intensity laser power to build functional parts out of CAD models and, hence, makes the process much simpler, cheaper, and adaptable. Past studies reveal that productivity of the FDM process can be further increased by effectively controlling its process parameters such as layer thickness, part orientation, extrusion temperature, and so on. In this regard, many authors have investigated the optimal parameter settings for improving part strength, surface finish, wear, and fatigue properties of FDM made prototypes. However, warping performance behavior has got very recent attention due to complex heat transfer mechanism involved during this process. Experimental investigations are necessary to understand the deformation behavior of prototypes. In addition, the quantification and optimization of warp deformation along with dimensional error poses a challenging multi-objective optimization problem. Therefore, this work proposes an evolutionary system identification (SI) approach to explicitly quantify the warp deformation and dimensional error based on the four inputs such as line width compensation, extrusion velocity, filling velocity, and layer thickness of FDM prototypes. The two models’ performance analysis comprising of error metrics evaluation, cross-validation, and hypothesis tests is performed to validate its robustness. The analysis concluded that the layer thickness and extrusion velocity influence the warp deformation and, while filling velocity and line width compensation, influences the dimensional error the most.

11 Left ventricular end diastolic filling pressure predicted by left atrial strain measured by feature tracking

Introduction Left ventricular end-diastolic filling pressure (LVEDP) is an invasive measure of LV function obtained at cardiac catheterisation (CC) that predicts prognosis and guides therapeutic strategy. Echocardiographic E/E’ ratio has been shown to be inaccurate for estimation of LVEDP. Feature-tracking cardiovascular magnetic resonance (FT-CMR) is a novel method for quantification of myocardial deformation and can be used to quantitatively assess left atrial (LA) function. Currently there is no validated MRI parameter that estimates LVEDP. We hypothesised that LA strain correlates to LVEDP. Methods 14 patients in sinus rhythm, with severe AS underwent a 1.5T CMR protocol (Ingenia, Phillips Healthcare, Best, The Netherlands). LVEDP was recorded at the time of CC by standard techniques. 4 chamber and mid ventricular short axis steady state free procession cine images were obtained: LA endocardial and epicardial borders were traced manually on the end-diastolic slice and strain measurements were calculated using commercially available post-processing software (CVI42, Circle Cardiovascular Imaging, Calgary, Alberta, Canada). Results Patients were divided into 2 groups: low EDP (13 ± 2.4mmHg) and high EDP (36.1 ± 3.4mmHg) (p Conclusion LA function (PALS) as measured by FT-CMR is independently associated with LVEDP and may have a role in predicting LV filling pressures via a routine CMR protocol.

NORMAL RANGES FOR MRI FEATURE TRACKING STRAIN: A SYSTEMATIC REVIEW AND META-ANALYSIS FROM 659 HEALTHY SUBJECTS

MRI based feature tracking (FT) is a novel technique for quantification of cardiac deformation. However, there are no guidelines or large sample-size studies to define the normal range of strain using MRI FT. We performed a systematic review of normal values and a meta-analysis to identify sources

Multicenter Comparison of 3D Spinal Measurements Using Surface Topography With Those From Conventional Radiography

IntroductionIn pediatric spinal deformity the gold standard for curve surveillance remains standing full-column radiographs, but repeated exposure to ionizing radiation motivates us to look for nonradiographic solutions. This study tests a modern system of surface topography (ST) to determine whether it is reliable and reproducible. MethodsPatients from 6 pediatric spinal deformity clinics were recruited for enrollment. Inclusion criteria were age 8-18; diagnosis of scoliosis measuring ≥10 and <50 degrees or increased kyphosis of ≥45 degrees. Standing radiographs and ST scans (DIERS Formetric, Diers Medical Systems, Chicago, IL) were obtained on all patients and then measured and compared. A single investigator using a validated electronic measurement tool performed all radiographic measurements. Analysis of reproducibility and comparison of ST and radiographs were done. ResultsA total of 193 patients were enrolled (148 F [77%]). The mean age was 13.25 years (range 8–18). The scoliosis magnitude was as follows: thoracic average 22.7 ± 10 degrees; lumbar average 19.6 ± 9 degrees. The kyphosis magnitude was 54.0 ± 11 degrees. The reproducibility for each ST parameter for 3 repeated scans was strong (interclass correlation = 0.855–0.944). Comparison to radiographic measurements was strong in the thoracic (r = 0.7) and moderate in the lumbar curve (r = 0.5). There was an average difference of 5.8 degrees in the thoracic spine and 8.8 degrees in the lumbar spine between ST Cobb angle estimates and radiographs. Thoracic kyphosis also had a strong correlation (r = 0.8) with radiographs. ConclusionsAlthough the results are intended to measure similar aspects of deformity as the traditional Cobb angle, the measurement is not intended to be an exact estimation. The utility of ST is in the reproducible quantification of deformity after the initial radiograph has been taken. This has the potential to make longitudinal assessment of change in deformity without serial radiographs.

Time-resolved synchrotron tomographic quantification of deformation during indentation of an equiaxed semi-solid granular alloy

Indentation is a well-established technique for measuring mechanical properties, such as hardness and creep, in solid materials at a continuum level. In this study, we performed indentation of a semi-solid granular alloy with an equiaxed dendritic microstructure. The resulting microstructural effects were quantified using a novel thermo-mechanical setup combined with 4D (three spatial dimensions plus time) synchrotron tomography and digital volume correlation. The experiments not only revealed the multitude of deformation mechanisms occurring at a microstructural level, (e.g. dilatancy, liquid flow, macrosegregation, shrinkage voids, and intra-granular deformation), but also allowed quantification of the evolution of the strain fields within the material. The resulting methodology is a powerful tool for assessing the evolution of localized deformation and hence material properties.

Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its Microstructure –Part III: Micro-tensile Behavior of Pre-strained Dual-phase Steel

Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its Microstructure –Part III: Micro-tensile Behavior of Pre-strained Dual-phase Steel

Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its Microstructure –Part II: Local Strain Mapping of Dual Phase Steel by a Combination Technique of Electron Backscatter Diffraction and Digital Image Correlation Methods

Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its Microstructure –Part II: Local Strain Mapping of Dual Phase Steel by a Combination Technique of Electron Backscatter Diffraction and Digital Image Correlation Methods

Right ventricular function and adaption after hemi-Fontan completion in children with hypoplastic left heart syndrome

Background The systemic right ventricle (RV) in patients with hypoplastic left heart syndrome (HLHS) is prone to failure. The complex geometry and contraction pattern of the systemic RV makes identification of patients at risk for failure challenging, especially in the light of radical changes in loading conditions during staged palliation. MRI allows for accurate quantification of cardiac volumes and provides assessment of the whole heart without restrictions in imaging planes. Recent advances in cardiac MRI analysis software allows for quantification of regional deformation from conventional balanced steady state free precession cine images. We sought to investigate changes in ventricular function before and after the hemi-Fontan (HF).

Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its Microstructure –Part I: Proposal of the Quantification Technique of the Punching Damage of the Dual Phase Steel

Quantification of Large Deformation with Punching in Dual Phase Steel and Change of its Microstructure –Part I: Proposal of the Quantification Technique of the Punching Damage of the Dual Phase Steel

DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第1報)−DP鋼の打抜きダメージの定量化手法の提案−

DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第1報)−DP鋼の打抜きダメージの定量化手法の提案−

DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第2報)−電子線後方散乱法とデジタル画像相間法を組み合わせたDP鋼の局所ひずみマッピング−

DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第2報)−電子線後方散乱法とデジタル画像相間法を組み合わせたDP鋼の局所ひずみマッピング−

DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第3報)−予ひずみを受けたDP鋼のマイクロ引張挙動−

DP鋼の打抜き大変形の定量的評価とそのミクロ組織変化(第3報)−予ひずみを受けたDP鋼のマイクロ引張挙動−

Technology Focus: Bit Technology and Bottomhole Assemblies (December 2015)

Technology Focus A bronze statue of Will Rogers provided by the state of Oklahoma in 1939 stands in a unique position in front of the entrance to the US House of Representatives chambers. Of the 100 statues provided by the 50 states, only Rogers’ statue is pointed toward the entrance of the House. Rogers, who derived much of his commentary material from Congress, said before he died, “Even after I’m gone, I’m gonna keep an eye on you.” In January 1975, President Gerald Ford delivered his first State of the Union address in the House of Representatives chambers. The United States had just survived the oil embargo of 1973, which resulted in a shortage of gasoline and high energy prices. Energy independence was the focus of his address to the nation and the impetus behind the Energy Policy and Conservation Act of 1975. The act contained three main components: (1) oil conservation through vehicle-fuel-economy standards, (2) the creation and direction of the Strategic Petroleum Reserve, and (3) the prohibition on crude-oil exports. While no legislation is perfect, the conservation of oil and the establishment of the Strategic Petroleum Reserve are ideas that still have merit today. But is the prohibition on crude-oil exports still necessary? The landscape has changed. The US in now a swing producer of crude. President Ford continued the vision statement in his State of the Union address. He pointed to goals for dependable and domestic energy. The loftiest goal he stated was, “We must develop our energy technology and resources so that the United States has the ability to supply a significant share of the energy needs of the free world by the end of this century.” While we did not achieve energy independence at the end of the century, that goal is now reachable. It was technology in oil exploration and extraction (shale oil) that increased our production by more than 80% since 2008. Demand has not kept up. Since June of 2014, oil prices have dropped 60%. The duration of the current low prices has already exceeded all downturns since the fall of 1985, when the Saudis, while losing market share to other nation members of the Organization of the Petroleum Exporting Countries, increased oil production to 10 million B/D. Technology will play an increasing role in the lower-commodity-price environment. Because horizontal and extended-reach wellbores account for the majority of the wells being drilled, technologies geared around that development will produce the highest returns. The understanding and proper application of rotary-steerable systems will continue to provide a step change in the way fields are developed. Bit technology continues to improve and innovate. It will take performance and skill by both operators and service companies to compete in today’s low-price environment. Technology developed and implemented during the boom will receive closer scrutiny and evaluation during the bust. For good fortune, legislators rub the left shoe of the Will Rogers statue on the way to chambers. That shoe has become worn, like that of the statue of St. Peter in Rome, by the touch of the devoted. In January of 2017, the US will swear in a new president and a new class of legislators. May the tradition continue and Will Rogers’ good fortune encourage sensible energy policy and favorable commodity prices. JPT Recommended additional reading at OnePetro: www.onepetro.org. SPE 173861 Precise Quantification of Deformation of the BHA for Improved Performance in Directional Drilling by Przemyslaw Kukian, Weatherford, et al. SPE/IADC 173168 Freeing Differential Stuck Pipe With Nitrogen Reduces Lost-in- Hole Drillstrings Significantly by Norbert Heitmann, Schlumberger, et al. SPE 174798 Analytical Model To Estimate the Directional Tendency of Point- and Push-the-Bit BHAs by Yuan Zhang, Halliburton, et al.

Abstract 11093: Layer-specific Quantification of Myocardial Deformation by Strain Echocardiography May Reveal the Mechanism of Preserved Left Ventricular Ejection Fraction in Patients With Hypertrophic Cardiomyopathy

Purpose: We aimed to evaluate compensatory mechanisms in hypertrophic cardiomyopathy (HCM) patients (pts) with preserved left-ventricular (LV) ejection fraction (EF). Methods: Speckle-tracking echocardiography (Vivid E9, GE) was performed in 50 HCM with preserved LV EF (38 m; 49± 14 y, all LV EF &gt; 55%) and 50 age, gender matched controls (38 m; 49±12 y). The global and segmental longitudinal (LS), circumferential (CS) and radial strain (RS) strains of endocardia (End), mid-wall and epicardia layers were analyzed using a novel layer-specific TTE. The ratio of End to epicardia strain (End/Epi) was calculated. Results: The LV EF were similar in pts and controls (64±8 vs 64±7 %, p=0.95). The diastolic function was significantly impaired in HCM pts compared with controls (E/E’:18.4±8.4 vs 8.6 ±2.4, p&lt;0.0001). The absolute value of LS and CS was reserved at apical End layers (-34±7 vs -35±6, p=0.44); the remaining segments and LV global LS and CS of three layers were significantly smaller (LS,-16±5 vs -22±3; CS -24±8 vs -33±7; p&lt;0.0001), and LS and CS End/Epi (1.7±0.3 vs 1.3±0.1, 3.4±1.1 vs 1.7±0.2 respectively, P &lt;0.0001) was significantly higher in HCM pts than in controls. The RS and LV twist were preserved in all LV segments (27±10 vs 24±12, p=0.19; 20±8 vs 18±5, p=0.33; respectively). In HCM pts, the LV LS value at basal and middle levels revealed significant negative correlations with LV relative wall thickness (r=–0.65, –0.59 and –0.60, –0.54, respectively , p&lt; 0.0001); and mild negative correlations (r=-0.33,-0.29, p&lt;0.0001). The LV CS value at all levels revealed mild correlations with relative wall thickness (r=-0.22, p&lt;0.05) . The LS were significantly reduced at the hypertrophic segments (Figure). Conclusions: In HCM patients with preserved LVEF, LV GLS was impaired, but apical End LS and basal End CS, LV RS as well as LV twist were maintained as the compensation for reduction LV LS and CS. The Bull’s eye of LS may help us to localize the lesion segments and define the type of HCM.

Quantification of deformation induced α’-martensite in Fe–19Cr–3Mn–4Ni–0.15C–0.15N austenitic steel by in situ magnetic measurements

An in situ magnetic device was employed to quantify the deformation induced martensite in a Fe–19Cr–3Mn–4Ni–0.15C–0.15N (wt-%) steel during tensile testing in the temperature range of −40 to 22°C. The new device consists of an electromagnetic field which serves to magnetise the martensite phase as it forms during tensile loading and a second coil to detect the effective electrical potential difference induced by the magnetisation of tensile specimens. To implement the in situ measurement system, a correlation was necessary between the induced electrical potential difference and the deformation induced martensite fractions during uniaxial static tensile tests. The correlation procedure was found to require only the quantification of deformation induced martensite content in a tensile specimen strained until fracture using an ex situ magnetic saturation unit.