scholarly journals Radiographic Marking of Patient’s Gravity Line on X-Ray Images

2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Chunhui Wu ◽  
Amir A. Mehbod ◽  
Ensor Transfeldt
Keyword(s):  
Sagittal Plane ◽  
Measurement Techniques ◽  
Force Plate ◽  
Outcome Evaluation ◽  
Radiology Department ◽  
Line Position ◽  
Motion Controller ◽  
Spinal Balance ◽  
X Ray ◽  
Gravity Line

Objective: To develop a clinically feasible apparatus for measuring and marking patient’s gravity line position on spinal x-ray images. Background: Spinal balance of patients with deformity or instability is an important clinical parameter for patient diagnosis, surgery planning and treatment outcome evaluation. Traditional assessment of spinal balance is performed on full spine x-ray images using C7 plumb line relative to central sacral line in the coronal plane or posterior superior corner of S1 in the sagittal plane. Researchers have developed measurement techniques using a force plate synchronized with x-ray equipment and offline x-ray image processing. The complexity of these techniques limits their clinical applications. In this study, we present a new system to mark gravity line directly on an x-ray image. Methods: The system consists of a force plate, a signal conditioner and processor, a motion controller and a motor assembly that moves a radio-opaque marker. The processor calculates the location of gravity line and marker position, and transmits motion commands to the motion controller, which drives a motor assembly and moves the marker to appropriate positions. The acquired x-ray image has a mark indicating the instantaneous gravity line position. Evaluation: A prototype was installed in the radiology department. More than 200 patients were instructed to stand on the force plate. Exposure was performed as in routine x-ray imaging. The system does not affect routine x-ray workflow and provides valuable information for spine surgeons.

Spinal Balance/Alignment—Clinical Relevance and Biomechanics

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Anoli Shah ◽  
Justin V. C. Lemans ◽  
Joseph Zavatsky ◽  
Aakash Agarwal ◽  
Moyo C. Kruyt ◽  
...  
Keyword(s):  
Social Interaction ◽  
Sagittal Balance ◽  
Sagittal Plane ◽  
The Body ◽  
Optimal Configuration ◽  
Sacral Slope ◽  
Sagittal Imbalance ◽  
Compensatory Mechanisms ◽  
Spinal Balance ◽  
Spinal Imbalance

In the anatomy of a normal spine, due to the curvatures in various regions, the C7 plumb line (C7PL) passes through the sacrum so that the head is centered over the pelvic-ball and socket hip and ankle joints. A failure to recognize malalignment in the sagittal plane can affect the patient's activity as well as social interaction due to deficient forward gaze. The sagittal balance configuration leads to the body undertaking the least muscular activities as possible necessary to maintain spinal balance. Global sagittal imbalance is energy consuming and often results in painful compensatory mechanisms that in turn negatively influence the patient's quality of life, self-image, and social interaction due to inability to maintain a horizontal gaze. Deformity, scoliosis, kyphosis, trauma, and/or surgery are some ways that this optimal configuration can be disturbed, thus requiring higher muscular activity to maintain posture and balance. Several parameters such as the thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and hip and leg positions influence the sagittal balance and thus the optimal configuration of spinal alignment. This review examines the clinical and biomechanical aspects of spinal imbalance, and the biomechanics of spinal balance as dictated by deformities—ankylosing spondylitis (AS), scoliosis and kyphosis; surgical corrections—pedicle subtraction osteotomies (PSO), long segment stabilizations, and consequent postural complications like proximal and distal junctional kyphosis. The study of the biomechanics involved in spinal imbalance is relatively new and thus the literature is rather sparse. This review suggests several potential research topics in the area of spinal biomechanics.

scholarly journals Towards a methodology for the characterisation of the fabric of wet clays using X-ray scattering

2019 ◽  
Vol 92 ◽  
pp. 01005
Author(s):  
Georgios Birmpilis ◽  
Reza Ahmadi-Naghadeh ◽  
Jelke Dijkstra
Keyword(s):  
Materials Science ◽  
Measurement Techniques ◽  
Invasive Technique ◽  
Colloidal Systems ◽  
Characteristic Distance ◽  
X Ray ◽  
Hydrophobic Coating ◽  
X Ray Scattering ◽  
Wide Range ◽  
Ray Scattering

X-ray scattering is a promising non-invasive technique to study evolving nano- and micromechanics in clays. This study discusses the experimental considerations and a successful method to enable X-ray scattering to study clay samples at two extreme stages of consolidation. It is shown that the proposed sample environment comprising flat capillaries with a hydrophobic coating can be used for a wide range of voids ratios ranging from a clay suspension to consolidated clay samples, that are cut from larger specimens of reconstituted or natural clay. The initial X-ray scattering results using a laboratory instrument indicate that valuable information on, in principal evolving, clay fabric can be measured. Features such as characteristic distance between structural units and particle orientations are obtained for a slurry and a consolidated sample of kaolinite. Combined with other promising measurement techniques from Materials Science the proposed method will help advance the contemporary understanding on the behaviour of dense colloidal systems of clay, as it does not require detrimental sample preparation

X-RAY PHOTOELECTRON SPECTROSCOPY STUDIES ON THE BONDING PROPERTIES OF AMORPHOUS CARBON NITRIDE FILMS SYNTHESIZED BY PULSED LASER DEPOSITION WITH DIFFERENT SUBSTRATE TEMPERATURES

2005 ◽  
Vol 12 (02) ◽  
pp. 185-195
Author(s):  
M. RUSOP ◽  
T. SOGA ◽  
T. JIMBO
Keyword(s):  
Pulsed Laser Deposition ◽  
Amorphous Carbon ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Measurement Techniques ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray ◽  
Amorphous Carbon Nitride ◽  
Substrate Temperatures

Amorphous carbon nitride films ( a-CN x) were deposited by pulsed laser deposition of camphoric carbon target with different substrate temperatures (ST). The influence of ST on the synthesis of a-CN x films was investigated. The nitrogen-to-carbon (N/C) and oxygen-to-carbon (O/C) atomic ratios, bonding state, and microstructure of the deposited a-CN x films were characterized by X-ray photoelectron spectroscopy and were confirmed by other standard measurement techniques. The bonding states between C and N , and C and O in the deposited films were found to be significantly influenced by ST during the deposition process. The N/C and O/C atomic ratios of the a-CN x films reached the maximum value at 400°C. ST of 400°C was proposed to promote the desired sp 3-hybridized C and the C 3 N 4 phase. The C–N bonding of C–N , C=N and C≡N were observed in the films.

scholarly journals Habitual Physical Activity as a Determinant of the Effect of Moderate Physical Exercise on Postural Control in Older Men

2012 ◽  
Vol 7 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Rafał Stemplewski ◽  
Janusz Maciaszek ◽  
Maciej Tomczak ◽  
Robert Szeklicki ◽  
Dorota Sadowska ◽  
...  
Keyword(s):  
Physical Activity ◽  
Postural Control ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Force Plate ◽  
Frontal Plane ◽  
Habitual Physical Activity ◽  
Similar Reaction ◽  
Mean Velocity ◽  
Ergometer Exercise

The aim of the study was to compare the effect of exercise on postural control (PC) among the elderly with lower or higher level of habitual physical activity (HPA). The study involved 17 elderly men (mean age 72.9 ± 4.79 years). Mean velocity of the center of pressure (COP) displacements was measured using a force plate both before and after cycle ergometer exercise. A significantly higher increase in mean velocity of COP displacements and its component in the sagittal plane were observed in the group with lower level of HPA in comparison with the group with higher HPA level. Simultaneously, a relatively similar reaction to the exercise in the frontal plane was observed in both groups, possibly connected to the specific type of used exercise, which mainly activated the sagittal muscles.

scholarly journals Evaluation of Effect of Posterior Dynamic Stabilization IntraSPIN System on Sagittal Spinal Balance using EOS® X-Ray Imaging System

2017 ◽  
Vol 08 (04) ◽  
Author(s):  
Simona Bistazzoni ◽  
Michelangelo De Angelis ◽  
Manuela D ercole ◽  
Carmela Chiaramonte ◽  
Antonio Carotenuto ◽  
...  
Keyword(s):  
Imaging System ◽  
Dynamic Stabilization ◽  
Spinal Balance ◽  
X Ray ◽  
X Ray Imaging ◽  
Posterior Dynamic Stabilization ◽  
Sagittal Spinal Balance

scholarly journals Diffracting-grain identification from electron backscatter diffraction maps during residual stress measurements: a comparison between the sin2ψ and cosα methods

2019 ◽  
Vol 52 (4) ◽  
pp. 828-843 ◽  
Author(s):  
Dorian Delbergue ◽  
Damien Texier ◽  
Martin Lévesque ◽  
Philippe Bocher
Keyword(s):  
Residual Stress ◽  
Grain Size ◽  
Tilt Angle ◽  
Measurement Errors ◽  
Electron Backscatter Diffraction ◽  
Measurement Techniques ◽  
Single Exposure ◽  
X Ray ◽  
Electron Backscatter ◽  
Backscatter Diffraction

X-ray diffraction (XRD) is a widely used technique to evaluate residual stresses in crystalline materials. Several XRD measurement methods are available. (i) The sin2ψ method, a multiple-exposure technique, uses linear detectors to capture intercepts of the Debye–Scherrer rings, losing the major portion of the diffracting signal. (ii) The cosα method, thanks to the development of compact 2D detectors allowing the entire Debye–Scherrer ring to be captured in a single exposure, is an alternative method for residual stress measurement. The present article compares the two calculation methods in a new manner, by looking at the possible measurement errors related to each method. To this end, sets of grains in diffraction condition were first identified from electron backscatter diffraction (EBSD) mapping of Inconel 718 samples for each XRD calculation method and its associated detector, as each method provides different sets owing to the detector geometry or to the method specificities (such as tilt-angle number or Debye–Scherrer ring division). The X-ray elastic constant (XEC) ½S 2, calculated from EBSD maps for the {311} lattice planes, was determined and compared for the different sets of diffracting grains. It was observed that the 2D detector captures 1.5 times more grains in a single exposure (one tilt angle) than the linear detectors for nine tilt angles. Different XEC mean values were found for the sets of grains from the two XRD techniques/detectors. Grain-size effects were simulated, as well as detector oscillations to overcome them. A bimodal grain-size distribution effect and `artificial' textures introduced by XRD measurement techniques are also discussed.

Validation of Power Measurement Techniques in Dynamic Lower Body Resistance Exercises

2007 ◽  
Vol 23 (2) ◽  
pp. 103-118 ◽  
Author(s):  
Prue Cormie ◽  
Jeffrey M. McBride ◽  
Grant O. McCaulley
Keyword(s):  
Data Collection ◽  
Power Output ◽  
Measurement Techniques ◽  
Force Plate ◽  
Power Measurement ◽  
Power Relationship ◽  
Lower Body ◽  
Position Transducer ◽  
Load Power ◽  
Body Resistance

The objective of this study was to investigate the validity of power measurement techniques utilizing various kinematic and kinetic devices during the jump squat (JS), squat (S) and power clean (PC). Ten Division I male athletes were assessed for power output across various intensities: 0, 12, 27, 42, 56, 71, and 85% of one repetition maximum strength (1RM) in the JS and S and 30, 40, 50, 60, 70, 80, and 90% of 1RM in the PC. During the execution of each lift, six different data collection systems were utilized; (1) one linear position transducer (1-LPT); (2) one linear position transducer with the system mass representing the force (1-LPT+MASS); (3) two linear position transducers (2-LPT); (4) the force plate (FP); (5) one linear position transducer and a force plate (1-LPT+FP); (6) two linear position transducers and a force place (2-LPT+FP). Kinetic and kinematic variables calculated using the six methodologies were compared. Vertical power, force, and velocity differed significantly between 2-LPT+FP and 1-LPT, 1-LPT+MASS, 2-LPT, and FP methodologies across various intensities throughout the JS, S, and PC. These differences affected the load–power relationship and resulted in the transfer of the optimal load to a number of different intensities. This examination clearly indicates that data collection and analysis procedures influence the power output calculated as well as the load–power relationship of dynamic lower body movements.

Synthesis and study of diaboleïte

1968 ◽  
Vol 36 (283) ◽  
pp. 933-939 ◽  
Author(s):  
R. E. Winchell ◽  
H. E. Wenden
Keyword(s):  
Water Vapour ◽  
Atmospheric Pressure ◽  
Stable Phase ◽  
Line Position ◽  
Natural Mineral ◽  
X Ray ◽  
Partial Pressures ◽  
Cell Dimensions ◽  
Natural And Synthetic

SummaryDiaboleïte has been synthesized between 25 and 100° C at atmospheric pressure and approximate water vapour partial pressures of 14·7 lb/in2. Under similar conditions at 170° C cumengéite appears to be the stable phase produced from a diaboleïte composition. Synthetic diaboleïte is much simpler morphologically than the natural mineral but the hemimorphic symmetry is more clearly demonstrated morphologically in the artificial specimens. A comparison of X-ray powder data for natural and synthetic diaboleïte shows almost exact detailed correspondence in line position and intensity between 0 and 180° 2θ. The cell dimensions obtained from X-ray powder data are a 5·869 ± 0·002 Å and c 5·495 ± 0·003 Å.

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