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An interactive eye-tracking system for measuring radiologists' visual fixations in volumetric CT images: Implementation and initial eye-tracking accuracy validation.

Med Phys 2021 Sep 17. Epub 2021 Sep 17.

Department of Radiology.

Purpose: Eye tracking approaches have been used to understand the visual search process in radiology. However, previous eye tracking work in computer tomography (CT) has been limited largely to single cross-sectional images or video playback of the reconstructed volume, which do not accurately reflect radiologists' visual search activities and their interactivity with 3-dimensional image data at a computer workstation (e.g. Read More

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September 2021

Scale-resolving Simulations of Steady and Pulsatile Flow Through Healthy and Stenotic Heart Valves.

J Biomech Eng 2021 Sep 16. Epub 2021 Sep 16.

Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands.

Blood-flow downstream of stenotic and healthy aortic valves exhibits intermittent random fluctuations in the velocity field which are associated with turbulence. Such flows warrant the use of computationally demanding scale-resolving models. The aim of this work was to compute and quantify this turbulent flow in healthy and stenotic heart valves for steady and pulsatile flow conditions. Read More

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September 2021

Simulations of dispersion through an irregular urban building array.

Atmos Environ (1994) 2021 Aug;258

Jacobs Technology, Inc. (JTI), Research Triangle Park, NC, USA.

Following the release of a harmful substance within an urban environment, buildings and street canyons create complex flow regimes that affect dispersion and localized effluent concentrations. While some fast-response dispersion models can capture the effects caused by individual buildings, further research is required to refine urban characterizations such as plume channeling and spreading, and initial dispersion, especially within the presence of a nonhomogeneous array of structures. Field, laboratory, and modeling experiments that simulate urban or industrial releases are critical in advancing current dispersion models. Read More

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Novel method for selecting slices of the same cross-sectional view from digital tomosynthesis for monitoring posterior spinal instrumentation.

J Clin Neurosci 2021 Oct 25;92:183-188. Epub 2021 Aug 25.

Department of Orthopedic Surgery, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.

Background: A method to evaluate pedicle screw loosening on digital tomosynthesis images is yet to be established owing to lack of methods for selecting slices of the same cross-sectional view. We aimed to develop an objective method for selecting slices of the same cross-sectional view on digital tomosynthesis images.

Methods: First, an objective method of pixel selection was developed by measuring the size of glass disk and titanium alloy screw on digital tomosynthesis images followed by comparison with the actual sizes. Read More

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October 2021

Evaluating Localization Accuracy of Automated Driving Systems.

Sensors (Basel) 2021 Aug 30;21(17). Epub 2021 Aug 30.

Mobility & Transport Analytics Group, Salzburg Research Forschungsgesellschaft mbH, 5020 Salzburg, Austria.

Automated driving systems are in need of accurate localization, i.e., achieving accuracies below 0. Read More

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Towards Endovascular Treatment of Type A Aortic Dissection with Smaller Landing Zones and More Patient Eligibility.

J Vasc Surg 2021 Sep 6. Epub 2021 Sep 6.

Department of Surgery, University of California San Francisco, San Francisco, CA, United States.

Objective: Type A or ascending aortic dissection is an acute life-threatening condition with high morbidity and mortality. Open surgery remains standard-of-care. Development of minimally invasive endografts for Type A aortic dissection (TAAD) will require detailed understanding of dissection and aortic root anatomy to determine patient eligibility and optimal device specifications. Read More

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September 2021

Implication of coughing dynamics on safe social distancing in an indoor environment-A numerical perspective.

Build Environ 2021 Dec 30;206:108280. Epub 2021 Aug 30.

Department of Engineering Technology and Industrial Distribution, Texas A&M University, College Station, TX, USA.

Coughing is a primary symptomatic pathway of respiratory or air-borne disease transmission, including COVID-19. Several parameters such as cougher's age, gender, and posture affect particle dispersion indoors. This study numerically investigates the transient cough evolution, contamination range, particle reach probability, and deposition fraction for different age groups of males and females in standing and sitting postures in a ventilated room. Read More

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December 2021

Algorithm of Pulmonary Vascular Segment and Centerline Extraction.

Comput Math Methods Med 2021 25;2021:3859386. Epub 2021 Aug 25.

Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China.

Because pulmonary vascular lesions are harmful to the human body and difficult to detect, computer-assisted diagnosis of pulmonary blood vessels has become the focus and difficulty of the current research. An algorithm of pulmonary vascular segment and centerline extraction which is consistent with the physician's diagnosis process is proposed for the first time. We construct the projection of maximum density, restore the vascular space information, and correct random walk algorithm to satisfy automatic and accurate segmentation of blood vessels. Read More

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Detection of 3D Arterial Centerline Extraction in Spiral CT Coronary Angiography.

J Healthc Eng 2021 21;2021:2670793. Epub 2021 Aug 21.

Changshu Hospital of Chinese Medicine, Changshu 215516, Jiangsu, China.

This paper presents an in-depth study and analysis of the 3D arterial centerline in spiral CT coronary angiography, and constructs its detection and extraction technique. The first time, the distance transform is used to complete the boundary search of the original figure; the second time, the distance transform is used to calculate the value of the distance transform of all voxels, and according to the value of the distance transform, unnecessary voxels are deleted, to complete the initial contraction of the vascular region and reduce the computational consumption in the next process; then, the nonwitnessed voxels are used to construct the maximum inner joint sphere model and find the skeletal voxels that can reflect the shape of the original figure. Finally, the skeletal lines were optimized on these initially extracted skeletal voxels using a dichotomous-like principle to obtain the final coronary artery centerline. Read More

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Phase Formation during Heating of Amorphous Nickel-Based BNi-3 for Joining of Dissimilar Cobalt-Based Superalloys.

Materials (Basel) 2021 Aug 16;14(16). Epub 2021 Aug 16.

Structural and Fire Engineering Division, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden.

Phase transformations and the melting range of the interlayer BNi-3 were investigated by differential scanning calorimetry, which showed three stages of crystallization during heating. There were three exothermic peaks that indicated crystallization in the solid state. The cobalt-based X-45 and FSX-414 superalloys were bonded with interlayer BNi-3 at a constant holding time of 10 min with bonding temperatures of 1010, 1050, 1100, and 1150 °C using a vacuum diffusion brazing process. Read More

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Greater Curvature, Centerline or Straightened Centerline Length - Which length is Most Accurate for Preprocedural Planning in Thoracic Endovascular Aortic Repair?

Ann Vasc Surg 2021 Aug 23. Epub 2021 Aug 23.

Department of Cardiovascular Radiology and Endovascular Interventions, All India Institute of Medical Sciences, New Delhi, India.

Background: Automated centerline (CL) measurements have been conventionally used for stent-graft length estimation during thoracic endovascular aortic repair (TEVAR). The purpose of this study was to assess the accuracy of greater curvature length (GL), semiautomated CL and straightened centerline length (SCL) for preprocedural planning in TEVAR.

Methods: Immediate postprocedural CT Angiographies of 30 patients (22 males, age-49. Read More

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Combining a multi-analyzer stage with a two-dimensional detector for high-resolution powder X-ray diffraction: correcting the angular scale.

J Appl Crystallogr 2021 Aug 7;54(Pt 4):1088-1099. Epub 2021 Jul 7.

ESRF, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France.

In a test experiment, a two-dimensional pixel detector was mounted on the nine-channel multi-analyzer stage of the high-resolution powder diffraction beamline ID22 at the ESRF. This detector replaces a bank of scintillation counters that detect the diffracted intensity passing via the analyzer crystals as the diffractometer arm is scanned. At each diffractometer detector arm angle 2Θ, a 2D image is recorded that displays nine distinct regions of interest corresponding to the diffraction signals transmitted by each of the analyzer crystals. Read More

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Investigation of speed and trajectory of motorcycle riders at curved road sections of two-lane rural roads under diverse lighting conditions.

J Safety Res 2021 09 17;78:138-145. Epub 2021 Jun 17.

Department of Civil Engineering, University of Thessaly, Volos, Greece.

Introduction: Vehicular accidents at horizontal curves are over-represented compared to accidents that occur at tangent sections. Investigations have been conducted aimed at identifying the major causes that result in higher accident risk, both in terms of severity and rate, at curved road sections. Excessive or abrupt changes in speeding and improper vertical position are cited as major factors of lane departure, whereas other factors (either human or environmental) have also been documented. Read More

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September 2021

Detection of vessel bifurcations in CT scans for automatic objective assessment of deformable image registration accuracy.

Med Phys 2021 Aug 12. Epub 2021 Aug 12.

Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.

Purpose: Objective assessment of deformable image registration (DIR) accuracy often relies on the identification of anatomical landmarks in image pairs, a manual process known to be extremely time-expensive. The goal of this study is to propose a method to automatically detect vessel bifurcations in images and assess their use for the computation of target registration errors (TREs).

Materials And Methods: Three image datasets were retrospectively analyzed. Read More

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Evaluations of pretensioner activation in rear impacts.

Traffic Inj Prev 2021 6;22(7):553-558. Epub 2021 Aug 6.

Ford Motor Company, Dearborn, Michigan.

Objective: Occupant kinematics and biomechanical responses are assessed with and without pretensioning of normally seated and out-of-position front-seat occupants in rear sled tests. The results are compared to recent studies.

Methods: Three series of rear sled tests were conducted at 24 and 40 km/h with a 2001 Ford Taurus. Read More

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Surgical Drill Guide for Insertion of an Infra-Acetabular Screw Based on an Anatomically Precontoured Plate System: A Cadaveric Study.

Biomed Res Int 2021 26;2021:2321504. Epub 2021 Jul 26.

Department of Trauma Surgery, Regensburg University Medical Center, Germany.

Purpose: Due to the anatomic structure of the pelvis, free-hand placement of screws in the acetabular fracture management can be difficult. Infra-acetabular screw fixation increases acetabular stability by distal fixation of the cup. Aim of this cadaveric study is to investigate if a plate-referenced drill guide can provide save placement of an infra-acetabular screw over a precontoured suprapectineal quadrilateral buttress plate (SQBP). Read More

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Does rapid maxillary expansion enlarge the nasal cavity and pharyngeal airway? A three-dimensional assessment based on validated analyses.

Orthod Craniofac Res 2021 Aug 5. Epub 2021 Aug 5.

Section of Orthodontics, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark.

Objectives: To evaluate the three-dimensional changes following rapid maxillary expansion (RME) of the nasal cavity (NC) and pharyngeal airway (PA) in growing patients, using innovative and validated evaluation methods and to investigate whether a correlation between skeletal expansion and increase in airway volume exists.

Settings And Sample Population: Records of patients who had cone beam computed tomography taken before and after orthodontic treatment with or without RME were retrospectively collected and divided into two groups: (a) RME, 39 patients (mean age 10.40 ± 1. Read More

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A study on the cyclist head kinematic responses in electric-bicycle-to-car accidents using decision-tree model.

Accid Anal Prev 2021 Sep 28;160:106305. Epub 2021 Jul 28.

The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Hunan 410082, China. Electronic address:

Due to the high frequent traffic accidents involving electric bicycles (E-bike), it urgently needs improved protection of cyclists, especially their heads. In this study, by adjusting the initial impact velocities of E-bike and car, initial impact angle between E-bike and car, initial E-bike impact location, and body size of cyclist, 1512 different accident conditions were constructed and simulated using a verified E-bike-to-car impact multi-body model. The cyclist's head kinematic responses including the head relative impact velocity, WAD (Wrap around distance) of head impact location and HIC (15 ms Head Injury Criterion) were collected from simulation results to make up a dataset for data mining. Read More

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September 2021

The utility of free abdominal flap without Zone 4 procedure for unilateral breast reconstruction.

Microsurgery 2021 Jul 31. Epub 2021 Jul 31.

Department of Plastic, Reconstructive and Aesthetic Surgery, Chiba University, Faculty of Medicine, Chiba City, Chiba, Japan.

Background: The perfusion concept of free abdominal flap for breast reconstruction shares the common perception. We believed that free abdominal flap without Zone 4 could be performed. The purpose of this study is to introduce the "without Zone 4 procedure" and compare with the conventional technique (without 4 vs. Read More

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Automated three-dimensional vessel reconstruction based on deep segmentation and bi-plane angiographic projections.

Comput Med Imaging Graph 2021 09 21;92:101956. Epub 2021 Jul 21.

Korea Institute of Medical Microrobotics, Gwangju, 61011, South Korea; School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, South Korea. Electronic address:

Automated three-dimensional (3D) blood vessel reconstruction to improve vascular diagnosis and therapeutics is a challenging task in which the real-time implementation of automatic segmentation and specific vessel tracking for matching artery sequences is essential. Recently, a deep learning-based segmentation technique has been proposed; however, existing state-of-the-art deep architectures exhibit reduced performance when they are employed using real in-vivo imaging because of serious issues such as low contrast and noise contamination of the X-ray images. To overcome these limitations, we propose a novel methodology composed of the de-haze image enhancement technique as pre-processing and multi-level thresholding as post-processing to be applied to the lightweight multi-resolution U-shaped architecture. Read More

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September 2021

Self-propulsion in 2D confinement: phoretic and hydrodynamic interactions.

Eur Phys J E Soft Matter 2021 Jul 20;44(7):97. Epub 2021 Jul 20.

Indian Institute of Technology Madras, Chennai, Tamil Nadu, 600036, India.

Chemically active Janus particles generate tangential concentration gradients along their surface for self-propulsion. Although this is well studied in unbounded domains, the analysis in biologically relevant environments such as confinement is scarce. In this work, we study the motion of a Janus sphere in weak confinement. Read More

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Understanding the Aorta-Spine Relation in Idiopathic Scoliosis: Value of Noncontrast CT-Derived Curved Coronal Reformats and 3D Volume Images.

Int J Spine Surg 2021 Aug 15;15(4):818-825. Epub 2021 Jul 15.

Department of Diagnostic and Interventional Radiology, Mansoura University, Faculty of Medicine, Mansoura, Egypt.

Background: Investigating axial position and longitudinal bending of the aorta in relation to spine curvature in adolescent idiopathic scoliosis patients could help surgeons in planning of spine surgeries.

Methods: Noncontrast computed tomography (CT) scans of 27 consecutive patients with adolescent idiopathic scoliosis (19 right and 8 left curves) and 16 control subjects were retrospectively reviewed. Using semiautomated software, centerline was drawn along the descending aorta, and curved reformat was generated. Read More

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Fast-ion D spectroscopy diagnostic at KSTAR.

Rev Sci Instrum 2021 Apr;92(4):043504

Korea Institute of Fusion Energy, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 34133, Republic of Korea.

A fast-ion Dα (FIDA) diagnostics system was installed for core and edge measurements on KSTAR. This system has two tangential FIDA arrays that cover both blue- and redshifted Dα lines (cold: 656.09 nm) in active views along the neutral beam 1 A centerline. Read More

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Fast whole-body motor neuron calcium imaging of freely moving Caenorhabditis elegans without coverslip pressed.

Cytometry A 2021 Jul 8. Epub 2021 Jul 8.

LMAM, School of Mathematical Sciences, Peking University, Beijing, China.

Caenorhabditis elegans (C. elegans) is an ideal model organism for studying neuronal functions at the system level. This article develops a customized system for whole-body motor neuron calcium imaging of freely moving C. Read More

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Technical note: Validation of 3D ultrasound for image registration during oncological liver surgery.

Med Phys 2021 Jul 5. Epub 2021 Jul 5.

Department of Surgical Oncology, The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Amsterdam, The Netherlands.

Purpose: Registration of pre- and intraoperative images is a crucial step of surgical liver navigation, where rigid registration of vessel centerlines is currently commonly used. When using 3D ultrasound (US), accuracy during navigation might be influenced by the size of the intraoperative US volume, yet the relationship between registration accuracy and US volume size is understudied. In this study, we specify an optimal 3D US volume size for registration using varying volumes of liver vasculature. Read More

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Angiography-Based 4-Dimensional Superficial Wall Strain and Stress: A New Diagnostic Tool in the Catheterization Laboratory.

Front Cardiovasc Med 2021 18;8:667310. Epub 2021 Jun 18.

Department of Cardiology, National University of Ireland Galway (NUIG), Galway, Ireland.

A novel method for four-dimensional superficial wall strain and stress (4D-SWS) is derived from the arterial motion as pictured by invasive coronary angiography. Compared with the conventional finite element analysis of cardiovascular biomechanics using the estimated pulsatile pressure, the 4D-SWS approach can calculate the dynamic mechanical state of the superficial wall , which could be directly linked with plaque rupture or stent fracture. The validation of this approach using models showed that the distribution and maximum values of superficial wall stress were similar to those calculated by conventional finite element analysis. Read More

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Detection of Geometric Risk Factors Affecting Head-On Collisions through Multiple Logistic Regression: Improving Two-Way Rural Road Design via 2+1 Road Adaptation.

Int J Environ Res Public Health 2021 06 19;18(12). Epub 2021 Jun 19.

Escuela de Ingenierías Industriales, Universidad de Valladolid, 47011 Valladolid, Spain.

This study aims to characterize locations on two-way rural roads where head-on crashes are more likely to occur, attending to geometric road design factors. For this purpose, a case-control study was carried out using multiple logistic regression models with variables related to road design parameters, considering several scenarios. The dataset corresponding to cases (places where crashes have occurred) was collected on Spanish "1+1" rural roads over a four-year period. Read More

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Variable-Order Fractional Models for Wall-Bounded Turbulent Flows.

Entropy (Basel) 2021 Jun 20;23(6). Epub 2021 Jun 20.

Division of Applied Mathematics, School of Engineering, Brown University, Providence, RI 02912, USA.

Modeling of wall-bounded turbulent flows is still an open problem in classical physics, with relatively slow progress in the last few decades beyond the log law, which only describes the intermediate region in wall-bounded turbulence, i.e., 30-50 y+ to 0. Read More

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Three-Dimensional Analysis of the In Vivo Motion of Implantable Cardioverter Defibrillator Leads.

Cardiovasc Eng Technol 2021 Jun 29. Epub 2021 Jun 29.

Department of Cardiology, Erasmus MC, Postbus 2040, 3000 CA, Rotterdam, The Netherlands.

Better understanding of the lead curvature, movement and their spatial distribution may be beneficial in developing lead testing methods, guiding implantations and improving life expectancy of implanted leads.

Objective: The aim of this two-phase study was to develop and test a novel biplane cine-fluoroscopy-based method to evaluate input parameters for bending stress in leads based on their in vivo 3D motion using precisely determined spatial distributions of lead curvatures. Potential tensile, compressive or torque forces were not subjects of this study. Read More

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Secondary-flow-aided single-train elastic-inertial focusing in low elasticity viscoelastic fluids.

Electrophoresis 2021 Jun 28. Epub 2021 Jun 28.

School of Mechanical Engineering, and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing, P. R. China.

Elastic-inertial focusing has attracted increasing interest in recent years due to the three-dimensional (3D) single-train focusing ability it offers. However, multi-train focusing, instead of single-train focusing, was observed in viscoelastic fluids with low elasticity as a result of the competition between inertia effect and viscoelasticity effect. To address this issue, we employed the secondary flow to facilitate single-train elastic-inertial focusing in low elasticity viscoelastic fluids. Read More

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