scholarly journals Computed Tomographic Image Analysis Based on FEM Performance Comparison of Segmentation on Knee Joint Reconstruction

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Seong-Wook Jang ◽  
Young-Jin Seo ◽  
Yon-Sik Yoo ◽  
Yoon Sang Kim
Keyword(s):  
Image Segmentation ◽  
Knee Joint ◽  
Movement Analysis ◽  
3D Models ◽  
Performance Comparison ◽  
Fe Analysis ◽  
Joint Movement ◽  
Computed Tomographic ◽  
Ct Data ◽  
Scan Data

The demand for an accurate and accessible image segmentation to generate 3D models from CT scan data has been increasing as such models are required in many areas of orthopedics. In this paper, to find the optimal image segmentation to create a 3D model of the knee CT data, we compared and validated segmentation algorithms based on both objective comparisons and finite element (FE) analysis. For comparison purposes, we used 1 model reconstructed in accordance with the instructions of a clinical professional and 3 models reconstructed using image processing algorithms (Sobel operator, Laplacian of Gaussian operator, and Canny edge detection). Comparison was performed by inspecting intermodel morphological deviations with the iterative closest point (ICP) algorithm, and FE analysis was performed to examine the effects of the segmentation algorithm on the results of the knee joint movement analysis.

scholarly journals The Natural Historian's Guide to the CT Galaxy: Step-by-Step Instructions for Preparing and Analyzing Computed Tomographic (CT) Data Using Cross-Platform, Open Access Software

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
T J Buser ◽  
O F Boyd ◽  
Á Cortés ◽  
C M Donatelli ◽  
M A Kolmann ◽  
...  
Keyword(s):  
Open Access ◽  
3D Printing ◽  
3D Visualization ◽  
3D Models ◽  
Digital Data ◽  
Anatomical Structures ◽  
Computed Tomographic ◽  
Biomechanical Models ◽  
Cross Platform ◽  
Ct Data

Synopsis The decreasing cost of acquiring computed tomographic (CT) data has fueled a global effort to digitize the anatomy of museum specimens. This effort has produced a wealth of open access digital three-dimensional (3D) models of anatomy available to anyone with access to the Internet. The potential applications of these data are broad, ranging from 3D printing for purely educational purposes to the development of highly advanced biomechanical models of anatomical structures. However, while virtually anyone can access these digital data, relatively few have the training to easily derive a desirable product (e.g., a 3D visualization of an anatomical structure) from them. Here, we present a workflow based on free, open source, cross-platform software for processing CT data. We provide step-by-step instructions that start with acquiring CT data from a new reconstruction or an open access repository, and progress through visualizing, measuring, landmarking, and constructing digital 3D models of anatomical structures. We also include instructions for digital dissection, data reduction, and exporting data for use in downstream applications such as 3D printing. Finally, we provide Supplementary Videos and workflows that demonstrate how the workflow facilitates five specific applications: measuring functional traits associated with feeding, digitally isolating anatomical structures, isolating regions of interest using semi-automated segmentation, collecting data with simple visual tools, and reducing file size and converting file type of a 3D model.

scholarly journals A Textile Sensor for Long Durations of Human Motion Capture

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2369 ◽  
Author(s):  
Sufeng Hu ◽  
Miaoding Dai ◽  
Tianyun Dong ◽  
Tao Liu
Keyword(s):  
Knee Joint ◽  
Motion Capture ◽  
Sports Medicine ◽  
Low Cost ◽  
Movement Analysis ◽  
Human Motion ◽  
Joint Movement ◽  
Human Motion Capture ◽  
Knee Joint Motion ◽  
Textile Sensor

Human posture and movement analysis is important in the areas of rehabilitation, sports medicine, and virtual training. However, the development of sensors with good accuracy, low cost, light weight, and suitability for long durations of human motion capture is still an ongoing issue. In this paper, a new flexible textile sensor for knee joint movement measurements was developed by using ordinary fabrics and conductive yarns. An electrogoniometer was adopted as a standard reference to calibrate the proposed sensor and validate its accuracy. The knee movements of different daily activities were performed to evaluate the performance of the sensor. The results show that the proposed sensor could be used to monitor knee joint motion in everyday life with acceptable accuracy.

scholarly journals In vivo personalized finite element modeling of the knee joint derived from MRI images

2009 ◽  
pp. 81-92
Author(s):  
Morgan Sangeux ◽  
Frédéric Marin ◽  
Fabrice Charleux ◽  
Marie-Christine Ho Ba Tho
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Finite Element Modeling ◽  
Movement Analysis ◽  
Nonlinear Finite Element ◽  
Joint Movement ◽  
Treatment Procedure ◽  
Element Modeling ◽  
Subject Specific

This paper adresses the methodology used to model the knee joint in vivo from MRI images. The knee joint model obtained is subject specific. The paper presents all the treatment procedure: Geometrical acquisitions, Joint movement analysis, Meshing techniques and nonlinear finite element modeling with contact between the bones, the cartilage and the menisci. The model provides the contact pressure applied on the various components of the joint for one normal subject.

scholarly journals Comparison of Accuracy for HKA by X-ray and Knee Motion Analysis System and the Relationships between HKA and Gait Posture

2021 ◽  
Author(s):  
Hui Zhang ◽  
Yanan Chen ◽  
Huiquan Jiang ◽  
Wenqing Yan ◽  
Yuanming Ouyang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Lower Limb ◽  
Degrees Of Freedom ◽  
Mechanical Axis ◽  
Movement Analysis ◽  
X Rays ◽  
Joint Movement ◽  
X Ray ◽  
Posterior Displacement ◽  
Analysis System

Abstract This study is aimed at obtaining the accuracy of the lower limb mechanical axis (Hip-Knee-Ankle, HKA) by the six degrees of freedom (6DOF) of the knee and ground gait data and analyzing the correlation between the lower limb mechanical axis and 6DOF. We analyzed 3D knee kinematics during ground gait of 99 patients with KOA and 80 patients 6 months after the operations with the vivo infrared navigation 3D portable knee joint movement analysis system (Opti-Knee®, Innomotion Inc, Shanghai, China). Significant correlations with low coefficients (r = -0.19, p = 0.01) between HKA value and anterior-posterior displacement for the whole cohort were found. There were significant correlations with moderate to high coefficients (r = 0.784 to 0.976) between the comparisons of HKA measured on the full-length alignment radiographs and 3D knee joint movement analysis system (Opti-Knee). The further linear correlation analysis showed that there was a significant correlation between the values of HKA measured by X-ray and movement analysis system(R2 = 0.90, p < 0.01). Data with equivalent results as HKA could be provided by knee joint movement analysis system comparing with the conventional X-rays. Nonetheless, there was low significance between the HKA and ground gait data .

Modeling the resistance mechanism of passive knee joint flexion and extension for use in rehabilitation equipment

2021 ◽  
pp. 095441192199013
Author(s):  
Mansoor Amiri ◽  
Farhad Tabatabai Ghomsheh ◽  
Farshad Ghazalian
Keyword(s):  
Knee Joint ◽  
Sagittal Plane ◽  
Resistance Mechanism ◽  
Time Dependent ◽  
Coefficient Of Determination ◽  
Joint Movement ◽  
Elastic Coefficient ◽  
Knee Movement ◽  
Joint Flexion ◽  
Flexion And Extension

The purpose of this study was to model the resistance mechanism of Passive Knee Joint Flexion and Extension to create a similar torque mechanism in rehabilitation equipment. In order to better model the behavior of passive knee tissues, it is necessary to exactly calculate the two coefficients of elasticity of time-independent and time-dependent parts. Ten healthy male volunteers (mean height 176.4+/−4.59 cm) participated in this study. Passive knee joint flexion and extension occurred at velocities of 15, 45, and 120 (degree/s), and in five consecutive cycles and within the range of 0 to 100° of knee movement on the sagittal plane on Cybex isokinetic dynamometer. To ensure that the muscles were relaxed, the electrical activity of knee muscles was recorded. The elastic coefficient, (KS) increased with elevating the passive velocity in flexion and extension. The elastic coefficient, (KP) was observed to grow with the passive velocity increase. While, the viscous coefficient (C) diminished with passive velocity rise in extension and flexion. The heightened passive velocity of the motion resulted in increased hysteresis (at a rate of 42%). The desired of passive velocity is lower so that there is less energy lost and the viscoelastic resistance of the tissue in the movement decreases. The Coefficient of Determination, R2 between the model-responses and experimental curves in the extension was 0.96 < R2 < 0.99 and in flexion was 0.95 < R2 < 0.99. This modeling is capable of predicting the true performance of the components of passive knee movement and we can create a resistance mechanism in the rehabilitation equipment to perform knee joint movement. Quantitative measurements of two elastic coefficients of Time-independent and Time-dependent parts passive knee joint coefficients should be used for better accurate simulation the behavior of passive tissues in the knee which is not seen in other studies.

scholarly journals An Anatomical Thermal 3D Model in Preclinical Research: Combining CT and Thermal Images

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1200
Author(s):  
Franziska Schollemann ◽  
Carina Barbosa Pereira ◽  
Stefanie Rosenhain ◽  
Andreas Follmann ◽  
Felix Gremse ◽  
...  
Keyword(s):  
Image Processing ◽  
Temperature Profile ◽  
3D Models ◽  
Animal Suffering ◽  
Preclinical Research ◽  
Thermal Images ◽  
Animal Trials ◽  
Superficial Skin ◽  
Ct Data ◽  
3D Information

Even though animal trials are a controversial topic, they provide knowledge about diseases and the course of infections in a medical context. To refine the detection of abnormalities that can cause pain and stress to the animal as early as possible, new processes must be developed. Due to its noninvasive nature, thermal imaging is increasingly used for severity assessment in animal-based research. Within a multimodal approach, thermal images combined with anatomical information could be used to simulate the inner temperature profile, thereby allowing the detection of deep-seated infections. This paper presents the generation of anatomical thermal 3D models, forming the underlying multimodal model in this simulation. These models combine anatomical 3D information based on computed tomography (CT) data with a registered thermal shell measured with infrared thermography. The process of generating these models consists of data acquisition (both thermal images and CT), camera calibration, image processing methods, and structure from motion (SfM), among others. Anatomical thermal 3D models were successfully generated using three anesthetized mice. Due to the image processing improvement, the process was also realized for areas with few features, which increases the transferability of the process. The result of this multimodal registration in 3D space can be viewed and analyzed within a visualization tool. Individual CT slices can be analyzed axially, sagittally, and coronally with the corresponding superficial skin temperature distribution. This is an important and successfully implemented milestone on the way to simulating the internal temperature profile. Using this temperature profile, deep-seated infections and inflammation can be detected in order to reduce animal suffering.

Computed Tomography in the Elderly: 1. the Normal Population

1980 ◽  
Vol 136 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Robin J. Jacoby ◽  
Raymond Levy ◽  
John M. Dawson
Keyword(s):  
Psychiatric Patients ◽  
Normal Population ◽  
The Elderly ◽  
Reciprocal Relationship ◽  
Cortical Atrophy ◽  
Global Rating ◽  
Computed Tomographic ◽  
Methodological Problems ◽  
Ct Data ◽  
Healthy Community

SummaryComputed tomographic (CT) and brief psychometric findings on 50 psychiatrically and neurologically healthy community residents over 60 years old are presented. The need for normative CT data is emphasized, and the methodological problems in obtaining them are discussed. Measures of ventricular size were generally found to be greater than those reported by other workers, and variation with age was also found to be less marked than hitherto reported. A reciprocal relationship was found between a global rating of cortical atrophy and a test of memory and orientation. This communication forms the basis for comparison with groups of psychiatric patients to be presented in subsequent articles.

scholarly journals An Investigation into a Gear-Based Knee Joint Designed for Lower Limb Prosthesis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
M. S. H. Bhuiyan ◽  
I. A. Choudhury ◽  
M. Dahari ◽  
Y. Nukman ◽  
S. Z. Dawal
Keyword(s):  
Knee Joint ◽  
Motion Analysis ◽  
Maximum Stress ◽  
Real Data ◽  
Fe Analysis ◽  
Knee Prostheses ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Lower Limb Prosthesis ◽  
Limb Prosthesis

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e−004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb.

Reciprocal Coactivation Patterns of the Lateral and Medial Quadriceps and Hamstrings during Low- and Moderate-Speed Isokinetic Movement

1998 ◽  
Vol 7 (3) ◽  
pp. 182-196 ◽  
Author(s):  
Ronald V. Croce ◽  
John P. Miller ◽  
Robert Confessore ◽  
James C. Vailas
Keyword(s):  
Knee Joint ◽  
Female Athletes ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Median Frequency ◽  
Vastus Medialis ◽  
Mean Square ◽  
Joint Movement ◽  
Surface Electrodes ◽  
Emg Patterns

The purpose of this study was to examine coactivation patterns of the lateral and medial quadriceps and the lateral and medial hamstrings during low- and moderate-speed isokinetic movements. Twelve female athletes performed isokinetic knee assessments at 60 and 180°/s. Root mean square electromyographic (rmsEMG) activity and the median frequency of the EMG (mfEMG) were determined by placing bipolar surface electrodes on the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and medial hamstrings (MH). Results of rmsEMG indicated that the VM showed almost twice the coactivation of the VL (p< .05), and that the BF showed almost four times the coactivation of the MH (p <.05). Finally, differences were noted in the mfEMG (p< .05), with the VM displaying different recruitment patterns at 180°/s as an agonist compared to that as an antagonist. Results indicated that when acting as antagonists, the VM and BE display the greatest EMG patterns during isokinetic knee joint movement.

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