115 research outputs found
Patient-Specific Design of Prosthesis for Below Knee Amputee: Analysis Between Different Gait
Major that often associated with prosthetic leg are poor comfort and high cost. The study is conducted to construct custom-made passive below knee prosthesis and to analyse the response to applied load in different gait condition. The scope of the study is the utilization of three-dimensional printing material, acrylonitrile butadiene styrene (ABS) in the manufacturing of prosthetic leg socket and pylon whereas the foot made from polyurethane. By using the Sense three-dimensional scanner, the subject\u27s residual leg was scanned. SolidWorks and Meshmixer were the software used for the three-dimensional designing of prosthetic leg parts. By using 3-Matic, aligning and meshing were carried out. von Mises stress and displacement of model applied with axial load were obtained from simulation using Marc Mentat. The load applied for midstance, heel strike and toe off phases were 350 N, 1545 N and 2450 N, respectively. The constraints position was different for each phase. The peak stress of the model was reported during toe off (20.86 MPa) followed by heel strike (13.41 MPa) and midstance (4.89 MPa). The stress during all three phases not exceeding the yield of respective materials. In displacement, the model experience highest displacement (54.95 MPa) during toe off and the lowest during midstance (6 mm). In conclusion prosthetic leg with ABS components shows acceptable durability during different gait
Finite Element Analysis of Different Pin Diameter of External Fixator in Treating Tibia Fracture
Biomechanical perspective of external fixator is one of the biggest elements that should be considered in treating fracture bone. This is due to the mechanical behavior of the structure could be analyzed and optimized in order to avoid failure, increase bone fracture healing rate and prevents preterm screw loosening. There are three significant factors that affect the stability of external fixator and those are the placement of pin at the bone, configuration and components of external fixator. All these factors contribute to a question, what is the optimum pin diameter which exerts good stress distribution? To date, the research on the above-mentioned factors are limited in the literature. Therefore, this study was conducted to evaluate the unilateral external fixator with different pin sizes in treating tibia shaft fracture via the finite element method. First and foremost, the development of the tibia shaft fracture was conducted using Mimics software. The computed tomography (CT) data image was utilized to develop three-dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the unilateral external fixator was developed using SolidWorks software. In this study, five pin diameters (4.5, 5.0, 5.5, 6.0 and 6.5 mm) were developed and analyzed. Both tibia bone and external fixator were meshed in 3-matic software. Simulation of this configuration took place in a finite element software, Marc.Mentat. From the findings, it is shown that the larger diameter of pin demonstrated the lowest stress distribution. The size of the 5.5mm pin shows optimum diameter in terms of stress distribution with the value of 21.50 MPa in bone and 143.33 MPa in fixator. Meanwhile the displacement value of 1.42mm in bone and 1.20mm in fixator. In conclusion, it is suggested that the pin diameter of 5.5 mm is the most favorable option in treating tibia shaft fracture in terms of mechanical perspective
Computer based x-ray computed tomography training system for engineering education
X-ray computed tomography (called CT) scanner is a powerful and widely used medical imaging modality in the hospital. The CT machine is very expensive and it can produce dangerous radiation when a person operates the machine. This makes it difficult for biomedical engineers and radiographer students to learn its working principles. In order to overcome this problem, a computer based CT scanner trainer system has been developed. The system is implemented using National Instrument’s Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW). At the beginning, it was started with the studying of existing CT scan machine. After gathering information, development process continued to develop generator component, x-ray tube subsystem, detector subsystem, imaging subsystem, and finally is reconstruction subsystem. The trainer system that has been developed is able to be used to train students on how to use CT scanner especially to get high quality images with lowest possible radiation. This will help biomedical engineers and radiographer students to have a better understanding of CT scanner in term of its working principle and to prevent radiation hazard during the learning process
Optimum processing of absorbable carbon nanofiber reinforced Mg–Zn composites based on two-level factorial design
To prevent a premature failure, absorbable magnesium implants must possess an adequate mechanical stability. Among many ways to improve the mechanical properties of magnesium is by particle reinforcement, such as using carbon nanofiber (CNF). This work reports an experimental design for optimum materials and processing of CNF-reinforced Mg–Zn composites based on a twolevel factorial design. Four factors were analyzed: percentage of CNF, compaction pressure, sintering temperature, and sintering time, for three recorded responses: elastic modulus, hardness, and weight loss. Based on the two-level factorial design, mechanical properties and degradation resistance of the composites reach its optimum at a composition of 2 wt % CNF, 400 MPa of compaction pressure, and 500?C of sintering temperature. The analysis of variance reveals a significant effect of all variables (p [removed] 0.0500). The elastic modulus and hardness reach their highest values at 4685 MPa and 60 Hv, respectively. The minimum and maximum weight loss after three days of immersion in PBS are recorded at 54% and 100%, respectively. This work concludes the percentage of CNF, compaction pressure, and sintering temperature as the main factors affecting the optimum elastic modulus, hardness, and degradation resistance of CNF-reinforced Mg–Zn composites
Comparative evaluation of medical thermal image enhancement techniques for breast cancer detection
Thermography is a potential medical imaging modality due to its capability in providing additional physiological information. Medical thermal images obtained from infrared thermography systems incorporate valuable temperature properties and profiles, which could indicate underlying abnormalities. The quality of thermal images is often degraded due to noise, which affects the measurement processes in medical imaging. Contrast stretching and image filtering techniques are normally adopted in medical image enhancement processes. In this study, a comparative evaluation of contrast stretching and image filtering on individual channels of true color thermal images was conducted. Their individual performances were quantitatively measured using mean square error (MSE) and peak signal to noise ratio (PSNR). The results obtained showed that contrast stretching altered the temperature profile of the original image while image filtering appeared to enhance the original image with no changes in its profile. Further measurement of both MSE and PSNR showed that the Wiener filtering method outperformed other filters with an average MSE value of 0.0045 and PSNR value of 78.739 dB. Various segmentation methods applied to both filtered and contrast stretched images proved that the filtering method is preferable for in-depth analysis
Finite element analysis of different pin diameter of external fixator in treating tibia fracture
Biomechanical perspective of external fixator is one of the biggest elements that should be considered in treating fracture bone. This is due to the mechanical behavior of the structure could be analyzed and optimized in order to avoid failure, increase bone fracture healing rate and prevents preterm screw loosening. There are three significant factors that affect the stability of external fixator and those are the placement of pin at the bone, configuration and components of external fixator. All these factors contribute to a question, what is the optimum pin diameter which exerts good stress distribution? To date, the research on the above-mentioned factors are limited in the literature. Therefore, this study was conducted to evaluate the unilateral external fixator with different pin sizes in treating tibia shaft fracture via the finite element method. First and foremost, the development of the tibia shaft fracture was conducted using Mimics software. The computed tomography (CT) data image was utilized to develop three-dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the unilateral external fixator was developed using SolidWorks software. In this study, five pin diameters (4.5, 5.0, 5.5, 6.0 and 6.5 mm) were developed and analyzed. Both tibia bone and external fixator were meshed in 3-matic software. Simulation of this configuration took place in a finite element software, Marc.Mentat. From the findings, it is shown that the larger diameter of pin demonstrated the lowest stress distribution. The size of the 5.5mm pin shows optimum diameter in terms of stress distribution with the value of 21.50 MPa in bone and 143.33 MPa in fixator. Meanwhile the displacement value of 1.42mm in bone and 1.20mm in fixator. In conclusion, it is suggested that the pin diameter of 5.5 mm is the most favorable option in treating tibia shaft fracture in terms of mechanical perspective
In Silico of Subject-Specific Progression of Knee Osteoarthritis: A Finite Element Analysis on Swing and Stance Phases
The clinical condition of joint pain and dysfunction induced by joint degeneration, osteoarthritis, affects more people than any other joint illness. Mechanical stress is a major contributor to the onset of osteoarthritis (OA). However, there is a difficulty of achieving direct quantitative measures of tissue behaviours during different grades of osteoarthritis and currently there is a lack of studies that explore the changes seen in cartilage effected by OA during swing and stance phases. Therefore, the purpose of this research is to look at the role of articular cartilage in the development of OA, as well as to evaluate and simulate the biomechanical behaviour of the knee joint under various boundary conditions by segmented knee joints from computed tomography datasets. Mimics software has been used to obtain the 3D model of the knee bones. In addition, the soft tissues were modelled using 3-matic software. Marc.Mentat software was used to correctly simulate the knee OA behaviour during the stance and swing phases for the nonlinear finite element analysis. During the stance and swing phases, the maximum von Mises stress and displacement on the femur, femoral cartilage, tibia, and tibial cartilage were collected for healthy, grade 1 and grade 2 osteoarthritis. The results reveal that when body weight load increased, so did stresses and displacements in articular cartilage and bones. This suggests that being overweight or obese may increase the risk of joint articular cartilage degeneration and osteoarthritis of the knee. In conclusion, based on the finite element analysis, the articular cartilage could be in a trouble if excessive forces are exerted towards it
In Silico of Subject-Specific Progression of Knee Osteoarthritis: A Finite Element Analysis on Swing and Stance Phases
The clinical condition of joint pain and dysfunction induced by joint degeneration, osteoarthritis, affects more people than any other joint illness. Mechanical stress is a major contributor to the onset of osteoarthritis (OA). However, there is a difficulty of achieving direct quantitative measures of tissue behaviours during different grades of osteoarthritis and currently there is a lack of studies that explore the changes seen in cartilage effected by OA during swing and stance phases. Therefore, the purpose of this research is to look at the role of articular cartilage in the development of OA, as well as to evaluate and simulate the biomechanical behaviour of the knee joint under various boundary conditions by segmented knee joints from computed tomography datasets. Mimics software has been used to obtain the 3D model of the knee bones. In addition, the soft tissues were modelled using 3-matic software. Marc.Mentat software was used to correctly simulate the knee OA behaviour during the stance and swing phases for the nonlinear finite element analysis. During the stance and swing phases, the maximum von Mises stress and displacement on the femur, femoral cartilage, tibia, and tibial cartilage were collected for healthy, grade 1 and grade 2 osteoarthritis. The results reveal that when body weight load increased, so did stresses and displacements in articular cartilage and bones. This suggests that being overweight or obese may increase the risk of joint articular cartilage degeneration and osteoarthritis of the knee. In conclusion, based on the finite element analysis, the articular cartilage could be in a trouble if excessive forces are exerted towards it
Biomechanical analysis of conventional and locking compression plate for treating fibula fracture: A finite element study
Background: Due to questionable effectiveness of malleolar fracture fixation, biomechanical study was conducted to compare the stability of One Third Tubular (OTT) Plate and Locking Compression Plate (LCP); 2) Methods: CT image of bone was used to develop 3D bone model while the plate was constructed in Solidwork with varied number of screws. Further, finite element study was conducted for both models where the bone and plate were defined as homogenous and isotropic material properties; 3) Results: For LCP, the highest VMS observed at the plate for 3 screws was 484 MPa, whereas for 5 screws plate was 667 MPa. Meanwhile, for OTT, the highest VMS at plate was observed for 3 screws was 300.5 MPa, whereas for 5 screw plate was 127.5 MPa. 4) Conclusion: Based on the results, it can be noted that the usage of 3 screw causing a lower VMS at plate compared to 5 screws. However, the relation is only valid for LCP. On the other hand, for OTT, 5-screw constructs giving a low VMS than 3-screw constructs. It can be concluded that the optimum stabilities of OTT and LCP were found at 5 screws and 3 screws, respectively
Biomechanical evaluation of pin placement of external fixator in treating tranverse tibia fracture: analysis on first and second cortex of cortical bone
Biomechanical perspective of external fixator is one of the greatest factor to consider in successfully treating bone fracture. This is due to the fact that mechanical behavior of the structure can be analyzed and optimized in order to avoid mechanical failure, increase bone fracture healing rate and prevent pre-term screw loosening. There are three significant factors that affect the stability of external fixator which are the placement of pin at the bone, configuration and components of external fixator. These factors lead to one question: what is the optimum pin placement in which exerts optimum stability? To date, literature on above mentioned factors is limited. Therefore, we conducted a study to evaluate the uniplanar-unilateral external fixator for two different pin placement techniques in treating transverse tibia fracture via finite element method. The study was started off with the development of transverse tibia fracture using Mimics software. Computed tomography (CT) data image was utilized to develop three dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the external fixator was developed using SolidWork software. Both tibia bone and external fixator were meshed in 3-matic software with triangular mesh element. Simulation of this configuration was took place in a finite element software, Marc.Mentat software. A load of 400 N was applied to the proximal tibia bone in order to simulate stance phase of a gait cycle. From the findings, the pin placement at the second cortex of bone provided optimum stability in terms of stress distribution and displacement, which should be considered for better treatment for transverse tibia fracture. On the other hand, the pin placement at first cortex should be avoided to prevent many complications
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