Prosthetic Modeling of the Femoral Head Based on Reverse Method

2011 ◽  
Vol 88-89 ◽  
pp. 225-229
Author(s):  
Bin Liu ◽  
Zhi Huan Huang ◽  
Xin Fan ◽  
Hao Jie Li
Keyword(s):  
Femoral Head ◽  
New Method ◽  
Head Model ◽  
Spatial Motion ◽  
Spatial Dynamic ◽  
Data Points ◽  
Lunate Surface ◽  
Reverse Method ◽  
Fitting Model ◽  
Sphere Fitting

In this paper, a new method for reconstructing the model of the necrotic femoral head is presented. It can reconstruct the optimal femoral head prosthesis model utilizing the reverse technology. This new method not only affords a theoretical model for the accurate operation position fixing in orthopaedic clinic, but also provides an innovative practical means for the individualized manufacturing of artificial femoral head prosthesis.The femoral head is regarded as a sphere. Then, the femoral head's configuration is reconstructed by means of fitting using the data points on the unspoiled acetabulum lunate surface. A spatial dynamic analysis is implemented, it is proved that the sphere fitting model can well satisfy the spatial motion relation between the femoral head and the acetabulum. The experiment results show that this method can well reconstruct the femoral head model of the target patient.

Prediction of Femoral Head Collapse in Osteonecrosis

2005 ◽  
Vol 128 (3) ◽  
pp. 467-470 ◽  
Author(s):  
K. Y. Volokh ◽  
H. Yoshida ◽  
A. Leali ◽  
J. F. Fetto ◽  
E. Y. S. Chao
Keyword(s):  
Femoral Head ◽  
Contact Problem ◽  
Contact Pressure ◽  
Cancellous Bone ◽  
Local Buckling ◽  
Young Modulus ◽  
Head Model ◽  
Element Mesh ◽  
Femoral Head Collapse ◽  
Cortical Shell

The femoral head deteriorates in osteonecrosis. As a consequence of that, the cortical shell of the femoral head can buckle into the cancellous bone supporting it. In order to examine the buckling scenario we performed numerical analysis of a realistic femoral head model. The analysis included a solution of the hip contact problem, which provided the contact pressure distribution, and subsequent buckling simulation based on the given contact pressure. The contact problem was solved iteratively by approximating the cartilage by a discrete set of unilateral linear springs. The buckling calculations were based on a finite element mesh with brick elements for the cancellous bone and shell elements for the cortical shell. Results of 144 simulations for a variety of geometrical, material, and loading parameters strengthen the buckling scenario. They, particularly, show that the normal cancellous bone serves as a strong supporting foundation for the cortical shell and prevents it from buckling. However, under the development of osteonecrosis the deteriorating cancellous bone is unable to prevent the cortical shell from buckling and the critical pressure decreases with the decreasing Young modulus of the cancellous bone. The local buckling of the cortical shell seems to be the driving force of the progressive fracturing of the femoral head leading to its entire collapse. The buckling analysis provides an additional criterion of the femoral head collapse, the critical contact pressure. The buckling scenario also suggests a new argument in speculating on the femoral head reinforcement. If the entire collapse of the femoral head starts with the buckling of the cortical shell then it is reasonable to place the reinforcement as close to the cortical shell as possible.

scholarly journals More faithfulness graph embedding

2015 ◽  
Vol 4 (2) ◽  
pp. 336
Author(s):  
Alaa Najim
Keyword(s):  
Dimensionality Reduction ◽  
Graph Embedding ◽  
New Method ◽  
Graph Representation ◽  
Data Sets ◽  
Graph Visualization ◽  
Graph Data ◽  
Original Space ◽  
Data Points ◽  
Effectiveness And Efficiency

<p><span lang="EN-GB">Using dimensionality reduction idea to visualize graph data sets can preserve the properties of the original space and reveal the underlying information shared among data points. Continuity Trustworthy Graph Embedding (CTGE) is new method we have introduced in this paper to improve the faithfulness of the graph visualization. We will use CTGE in graph field to find new understandable representation to be more easy to analyze and study. Several experiments on real graph data sets are applied to test the effectiveness and efficiency of the proposed method, which showed CTGE generates highly faithfulness graph representation when compared its representation with other methods.</span></p>

scholarly journals Enhancing Both Efficiency and Representational Capability of Isomap by Extensive Landmark Selection

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Dong Liang ◽  
Chen Qiao ◽  
Zongben Xu
Keyword(s):  
Manifold Learning ◽  
Computational Efficiency ◽  
New Method ◽  
Data Sets ◽  
Learning Approaches ◽  
Real World Data ◽  
Efficiency Property ◽  
Data Points ◽  
Low Dimensional ◽  
High Computational Efficiency

The problems of improving computational efficiency and extending representational capability are the two hottest topics in approaches of global manifold learning. In this paper, a new method called extensive landmark Isomap (EL-Isomap) is presented, addressing both topics simultaneously. On one hand, originated from landmark Isomap (L-Isomap), which is known for its high computational efficiency property, EL-Isomap also possesses high computational efficiency through utilizing a small set of landmarks to embed all data points. On the other hand, EL-Isomap significantly extends the representational capability of L-Isomap and other global manifold learning approaches by utilizing only an available subset from the whole landmark set instead of all to embed each point. Particularly, compared with other manifold learning approaches, the data manifolds with intrinsic low-dimensional concave topologies and essential loops can be unwrapped by the new method more successfully, which are shown by simulation results on a series of synthetic and real-world data sets. Moreover, the accuracy, robustness, and computational complexity of EL-Isomap are analyzed in this paper, and the relation between EL-Isomap and L-Isomap is also discussed theoretically.

New Method for the Treatment of Early Forms of Femoral Head Aseptic Necrosis (Preliminary Report)

2011 ◽  
Vol 18 (1) ◽  
pp. 33-37
Author(s):  
Il'dar Fuatovich Akhtyamov ◽  
O G Anisimov ◽  
Yu V Budyak ◽  
A N Kovalenko ◽  
A S Korotkova ◽  
...  
Keyword(s):  
Femoral Head ◽  
Total Hip Arthroplasty ◽  
Conservative Treatment ◽  
Preliminary Report ◽  
Pain Syndrome ◽  
Course Completion ◽  
New Method ◽  
Functional Abilities ◽  
Joint Region ◽  
Aseptic Necrosis

The authors have elaborated a new method for conservative treatment of femoral head aseptic necrosis (FHAN) at early stages of the disease (prior to cartilaginous layer collapse). The method consists of performance of prolonged epidural analgesia by administration of local anesthetic through epidural catheter with dosed speed for 6 - 8 days. Drug sympathectomy results in vascular tension drop that favours the improvement of microcirculation in hip joint region. Results of that method application in 24 patients show that it enables to cup off the pain syndrome and restore patient's functional abilities directly after treatment course completion. Remission lasts for up to 12 months. Application of the proposed method enables to postpone performance of total hip arthroplasty for the period of up to 6 years.

Ultrasound of femoral head cartilage: a new method of assessing bone age

1995 ◽  
Vol 24 (3) ◽  
pp. 197-200 ◽  
Author(s):  
A. Castriota-Scanderbeg ◽  
V. De Micheli
Keyword(s):  
Femoral Head ◽  
Bone Age ◽  
New Method ◽  
Femoral Head Cartilage

scholarly journals COMBINED IMPACTION AUTOPLASTY OF THE FEMORAL HEAD IN THE TREATMENT OF PATIENTS WITH EARLY STAGES OF ASEPTIC NECROSIS

2017 ◽  
Vol 2 (3) ◽  
pp. 39-44
Author(s):  
DS S Kudashev ◽  
SD D Zuev-Ratnikov ◽  
IS S Shorin
Keyword(s):  
Femoral Head ◽  
Pain Syndrome ◽  
Pathological Process ◽  
Diagnostic Methods ◽  
New Method ◽  
Harris Hip Score ◽  
Aseptic Necrosis ◽  
Early Stages ◽  
Functional Capabilities ◽  
Results Of Treatment

Aseptic necrosis of the femoral head refers to the number of severe, rapidly progressing destructive-dystrophic hip joint lesions. In the overwhelming majority of cases, the disease develops in young and most active age group. In the absence of necessary treatment, the result of the disease is the early disability retirement with the need for radical reconstructive interventions on the joint. The use of modern diagnostic methods makes it possible to detect the beginning of the pathological process in the femoral head in the early stages and to conduct the most effective treatment of patients of this category. Aim - to improve the results of treatment of patients with early stages of aseptic necrosis of the femoral head due to the development and introduction into clinical practice of a new method of combined impaction autoplasty of the femoral head. Materials and methods. A new method of combined impaction autoplasty of the femoral head was used, including decompression, intraosseous resection and excision of the focus of osteonecrosis followed by combined autoplasty of the postresection defect (RF patent No. 2583577 dated 13.04.2016). Intraosseous resection of the focus of destruction of the femoral head was performed with the help of a specially developed device - milling cutters for bone tissue resection (RF patent for utility model No. 171951 dated 21.06.2017). Evaluation of the effectiveness of the treatment was carried out on the basis of the severity of the pain syndrome and functional capabilities of patients defined by the Harris scale (Harris Hip Score). Results. The analysis of the medium-term results of the conducted treatment showed that good results were obtained in 67.4% of cases in which the proposed method was used.

Fast and simple dataset selection for machine learning

2019 ◽  
Vol 67 (10) ◽  
pp. 833-842
Author(s):  
Timm J. Peter ◽  
Oliver Nelles
Keyword(s):  
New Method ◽  
Complex Method ◽  
Optimal Point ◽  
Point Distribution ◽  
New Approach ◽  
Original Dataset ◽  
Representative Subset ◽  
New Strategy ◽  
Data Points ◽  
Space Filling Design

Abstract The task of data reduction is discussed and a novel selection approach which allows to control the optimal point distribution of the selected data subset is proposed. The proposed approach utilizes the estimation of probability density functions (pdfs). Due to its structure, the new method is capable of selecting a subset either by approximating the pdf of the original dataset or by approximating an arbitrary, desired target pdf. The new strategy evaluates the estimated pdfs solely on the selected data points, resulting in a simple and efficient algorithm with low computational and memory demand. The performance of the new approach is investigated for two different scenarios. For representative subset selection of a dataset, the new approach is compared to a recently proposed, more complex method and shows comparable results. For the demonstration of the capability of matching a target pdf, a uniform distribution is chosen as an example. Here the new method is compared to strategies for space-filling design of experiments and shows convincing results.

An Innovative Design and Structural Mechanics Analysis of Artificial Hip Joint

2013 ◽  
Vol 694-697 ◽  
pp. 3094-3100
Author(s):  
Zhi Hui Qian ◽  
Jia Jia Wang ◽  
Lei Ren ◽  
Lu Quan Ren ◽  
Tao Xu
Keyword(s):  
Femoral Head ◽  
Hip Joint ◽  
Stress Responses ◽  
Shielding Effect ◽  
Head Model ◽  
Femur Head ◽  
Fe Method ◽  
Artificial Hip Joint ◽  
Artificial Hip ◽  
Micropore Size

Using finite element (FE) method, this work established and comparatively analyzed the basic femoral head model, and six innovative femoral head models with different micropore surface distribution, aiming to explore the most rational surface morphology to have better effect on artificial hip implant. The inboard and outboard femur, the metal handle, and the femoral head’ stress responses were concerned. As the results showed, compared with type A (original femur head, with “smoothed” surface), the other six shaped femur head design all have reduced the maximal stress with different degrees. However, femur model surface type C arranged with 1mm-diametre distributed in three rows of micropore caused the best effect. Within the scope of the study, both micropore size and arranging way influenced the stress distribution at key components of artificial hip joint, especially the effect of micropore size exceeded arranging way of them. Based on the simulation results, it is proposed the whole rigidity of the artificial femoral head with microporous morphology, was reduced to some degree and therefore reducing the stress shielding effect, decreasing the possibility of embedded part being deformed or flexible, which is beneficial to improving life span of the prosthesis.

Dynamic ultrasonographic measurement of passive coxofemoral joint laxity in puppies

1997 ◽  
Vol 33 (3) ◽  
pp. 275-281 ◽  
Author(s):  
RT O'Brien ◽  
RT Dueland ◽  
WC Adams ◽  
J Meinen
Keyword(s):  
Standard Deviation ◽  
Femoral Head ◽  
Correlation Coefficient ◽  
Joint Laxity ◽  
New Method ◽  
One Year

A new method of dynamic ultrasonographic evaluation of passive coxofemoral joint laxity was used to examine a total of 30 greyhound (n = 13) and nongreyhound (n = 17) puppies. Puppies were evaluated sonographically at four, six, eight, 12, 16, and 26 weeks of age. The coxofemoral joints were distracted manually, and the femoral head displacements were measured during distraction. The greyhounds had significantly smaller (p less than 0.01) maximum distraction distance (mean +/- standard deviation [SD], 0.11 +/- 0.04 cm) than nongreyhound puppies (mean +/- SD, 0.26 +/- 0.10 cm). In six- to eight-week-old puppies, the maximum distraction distance was correlated significantly (p of 0.0001, adjusted correlation coefficient [r2] of 0.27) with stress radiographic indices. Coxofemoral joints interpreted as being abnormal on hip-extended radiographs taken at one year of age were associated significantly (p of 0.0001) with higher maximum distraction distances in six- to eight-week-old puppies.

scholarly journals Computing knots by quadratic and cubic polynomial curves

2020 ◽  
Vol 6 (4) ◽  
pp. 417-430
Author(s):  
Fan Zhang ◽  
Jinjiang Li ◽  
Peiqiang Liu ◽  
Hui Fan
Keyword(s):  
Convex Polygon ◽  
Degree Of Freedom ◽  
Quadratic Polynomial ◽  
New Method ◽  
Surface Generation ◽  
Affine Invariant ◽  
Determine Parameter ◽  
Polynomial Curve ◽  
Data Points ◽  
Cubic Polynomial

AbstractA new method is presented to determine parameter values (knot) for data points for curve and surface generation. With four adjacent data points, a quadratic polynomial curve can be determined uniquely if the four points form a convex polygon. When the four data points do not form a convex polygon, a cubic polynomial curve with one degree of freedom is used to interpolate the four points, so that the interpolant has better shape, approximating the polygon formed by the four data points. The degree of freedom is determined by minimizing the cubic coefficient of the cubic polynomial curve. The advantages of the new method are, firstly, the knots computed have quadratic polynomial precision, i.e., if the data points are sampled from a quadratic polynomial curve, and the knots are used to construct a quadratic polynomial, it reproduces the original quadratic curve. Secondly, the new method is affine invariant, which is significant, as most parameterization methods do not have this property. Thirdly, it computes knots using a local method. Experiments show that curves constructed using knots computed by the new method have better interpolation precision than for existing methods.

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