Implementation methods of FPGA-based shaft angle demodulation

2014 ◽  
Author(s):  
Wenbo Zhao
Keyword(s):  
Shaft Angle

scholarly journals Reconstruction of the Hip in Multiple Hereditary Exostoses

Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 490
Author(s):  
Dong Hoon Lee ◽  
Dror Paley
Keyword(s):  
Hip Joint ◽  
Joint Involvement ◽  
Neck Shaft Angle ◽  
Multiple Hereditary Exostoses ◽  
Femur Neck ◽  
Radiographic Outcomes ◽  
Surgical Dislocation ◽  
Center Edge ◽  
Shaft Angle ◽  
Coxa Valga

The hip joint involvement in multiple hereditary exostoses (MHE) occurs in 30–90%, causing pain and limitation of motion by femoroacetabular impingement, coxa valga, acetabular dysplasia, hip joint subluxation, and osteoarthritis. The purpose of this study was to investigate the clinical and radiographic outcomes of ten hips in seven patients treated by surgical dislocation and corrective osteotomies between 2004 and 2009. Surgical dislocation and excision of the osteochondromas and varus intertrochanteric osteotomies were performed in all cases when the neck–shaft angle was > 150°. Common sites of osteochondromas were medial, posterior, and anterior neck of the femur. Neck–shaft angle of the femur was improved from a mean of 157° to 139°, postoperatively. On an average, the center-edge angle improved from 20° to 30° postoperatively. We believe that Ganz’s safe surgical dislocation technique is the preferred treatment of MHE. This safeguards the circulation of the femoral head and the osteochondromas can be resected under direct vision. It can be combined with additional corrective osteotomies because the hip affected by MHE is frequently associated with dysplastic changes which can result in premature osteoarthritis.

The association between femoral neck shaft angle and degenerative disease of the hip in a cadaveric model

2021 ◽  
pp. 112070002110130
Author(s):  
Leigh-Anne Tu ◽  
Douglas S Weinberg ◽  
Raymond W Liu
Keyword(s):  
Femoral Head ◽  
Femoral Neck ◽  
Hip Osteoarthritis ◽  
Volume Ratio ◽  
Femoral Head Coverage ◽  
Neck Shaft Angle ◽  
Hip Arthritis ◽  
Femoral Version ◽  
Shaft Angle ◽  
The Impact

Background: While the influences of acetabular dysplasia and overcoverage on hip arthritis have been studied, the impact of femoral neck-shaft angle on hip arthritis is much more poorly understood. The purpose of this study is to determine if a relationship exists between neck shaft angle and the development of osteoarthritis, a better understanding of which would be useful to surgeons planning osteotomies about the hip. Methods: 533 cadaveric femora and acetabulae (1066 total) from the Hamann-Todd Osteological Collection (Cleveland, OH) were acquired. We measured true neck shaft angle using an AP photograph with the femoral neck parallel to the table. Femoral head volume to acetabular volume ratio, representing femoral head coverage, as well as femoral version were utilised. Correlation between neck shaft angle, femoral version, femoral head coverage and osteoarthritis were evaluated with multiple regression analysis. Results: The mean age and standard deviation was 56 ± 10 years. There were 64 females (12%) and 469 males. There were 380 Caucasians (71%) and 153 African-Americans. Mean femoral version was 11° ± 12° and mean true neck shaft angle was 127.7° ± 5.9° There was a strong correlation between age and arthritis (standardised beta 0.488, p < 0.001). There was a significant correlation between increasing true neck shaft angle and decreasing hip arthritis (standardised beta -0.024, p = 0.038). In the femoral head overcoverage subset, increasing true neck shaft angle was still significantly associated with decreasing hip arthritis (standardised beta −0.088, p = 0.018), although this relationship was not significant with femoral head undercoverage subset. Conclusions: With sufficient acetabular coverage, a relative increase in femoral neck shaft angle within the physiologic range is associated with decreased hip osteoarthritis. Clinical relevance: An understanding of the relationship between femoral neck shaft angle and hip osteoarthritis could be useful for surgeons planning pelvic or proximal femur osteotomies in children.

scholarly journals Low-Cost Calibration of Matching Error between Lidar and Motor for a Rotating 2D Lidar

2021 ◽  
Vol 11 (3) ◽  
pp. 913
Author(s):  
Chang Yuan ◽  
Shusheng Bi ◽  
Jun Cheng ◽  
Dongsheng Yang ◽  
Wei Wang
Keyword(s):  
Point Cloud ◽  
Low Cost ◽  
Shape Error ◽  
3D Point Cloud ◽  
Motor Shaft ◽  
Matching Error ◽  
Triangular Plate ◽  
Attitude Error ◽  
Shaft Angle ◽  
The Cost

For a rotating 2D lidar, the inaccurate matching between the 2D lidar and the motor is an important error resource of the 3D point cloud, where the error is shown both in shape and attitude. Existing methods need to measure the angle position of the motor shaft in real time to synchronize the 2D lidar data and the motor shaft angle. However, the sensor used for measurement is usually expensive, which can increase the cost. Therefore, we propose a low-cost method to calibrate the matching error between the 2D lidar and the motor, without using an angular sensor. First, the sequence between the motor and the 2D lidar is optimized to eliminate the shape error of the 3D point cloud. Next, we eliminate the attitude error with uncertainty of the 3D point cloud by installing a triangular plate on the prototype. Finally, the Levenberg–Marquardt method is used to calibrate the installation error of the triangular plate. Experiments verified that the accuracy of our method can meet the requirements of the 3D mapping of indoor autonomous mobile robots. While we use a 2D lidar Hokuyo UST-10LX with an accuracy of ±40 mm in our prototype, we can limit the mapping error within ±50 mm when the distance is no more than 2.2996 m for a 1 s scan (mode 1), and we can limit the mapping error within ±50 mm at the measuring range 10 m for a 16 s scan (mode 7). Our method can reduce the cost while the accuracy is ensured, which can make a rotating 2D lidar cheaper.

scholarly journals Femoral Version, Neck-Shaft Angle, and Acetabular Anteversion in Chinese Han Population

Medicine ◽  
2015 ◽  
Vol 94 (21) ◽  
pp. e891 ◽  
Author(s):  
Nan Jiang ◽  
Lin Peng ◽  
Mohammed Al-Qwbani ◽  
Guo-Ping Xie ◽  
Qin-Meng Yang ◽  
...  
Keyword(s):  
Chinese Han Population ◽  
Acetabular Anteversion ◽  
Chinese Han ◽  
Han Population ◽  
Neck Shaft Angle ◽  
Femoral Version ◽  
Shaft Angle

The effect of neck-shaft angle, glenosphere size, and cup depth on contact mechanics in reverse shoulder arthroplasty

2016 ◽  
Vol 25 (10) ◽  
pp. e320-e322
Author(s):  
G. Daniel G. Langohr ◽  
Ryan Willing ◽  
John B. Medley ◽  
James A. Johnson ◽  
George S. Athwal
Keyword(s):  
Contact Mechanics ◽  
Shoulder Arthroplasty ◽  
Reverse Shoulder Arthroplasty ◽  
Neck Shaft Angle ◽  
Shaft Angle

Kinematic design and motion analysis of spatial rapier drive mechanisms used in weaving machines

2014 ◽  
Vol 84 (19) ◽  
pp. 2065-2073 ◽  
Author(s):  
Recep Eren ◽  
Mesrur Erturk ◽  
Barıs Hascelik
Keyword(s):  
Motion Analysis ◽  
Kinematic Analysis ◽  
Gear Ratio ◽  
Main Shaft ◽  
Drive Mechanism ◽  
Spatial Mechanism ◽  
Kinematic Design ◽  
Shaft Angle

This paper presents an approach for the kinematic design of a rapier drive mechanism containing a spatial mechanism and analyses rapier motion curve. Kinematic design and analysis equations are derived and then the link lengths of the spatial mechanism are calculated in order to satisfy the critical rapier positions inside and outside the shed. In this way, the portions of one loom revolution, during which the rapiers are inside and outside the shed, are determined. The rapier motion curve is obtained by using kinematic analysis equations. It is shown that the position of the oscillating link in the spatial mechanism and the loom main shaft angle at which the rapier enters the shed have the most significant effect on the rapier motion curve. The gear ratio has also some effect on the rapier motion curve. Different rapier motion curves are obtained by changing these parameters and the suitability of these curves for rapier motion is discussed.

scholarly journals The Influence of Design Parameters on Straight Bevel Gear Dynamics

2015 ◽  
Vol 5 (2) ◽  
pp. 114
Author(s):  
Chiu-Fan Hsieh ◽  
You-Qing Zhu
Keyword(s):  
Statistical Analysis ◽  
The Other ◽  
Design Parameters ◽  
Bevel Gears ◽  
Straight Bevel Gear ◽  
Pressure Angle ◽  
Stress Fluctuation ◽  
Shaft Angle ◽  
Statistical Results ◽  
Component Force

<p class="1Body">This study analyzes the influence of design parameters on the dynamics of straight bevel gears by constructing a model that allows variation in the shaft angle, pressure angle, and backlash. According to the statistical analysis, the order of influence of these parameters on weight is shaft angle &gt; pressure angle &gt; backlash. When the shaft angle is 90°, the statistical results show the drive is stable and the stress fluctuation level is low. The pressure angle, on the other hand, can affect the gear’s dynamic property by influencing the driving component force on the gear and the component force on the shaft. The results for the shaft and pressure angles are used to determine the appropriate backlash. Overall, the analysis not only provides designers with an important reference but explains the dominance in the market of gear designs with a 90° shaft angle and a 20° pressure angle.</p>

The relevance of neutral arm positioning for true ap-view X-ray to provide true projection of the humeral head shaft angle

2015 ◽  
Vol 136 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Clemens Hengg ◽  
Peter Mayrhofer ◽  
Simon Euler ◽  
Markus Wambacher ◽  
Michael Blauth ◽  
...  
Keyword(s):  
Humeral Head ◽  
X Ray ◽  
Shaft Angle ◽  
Head Shaft Angle
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