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2023 |
Mihcin, Senay; Sahin, Ahmet Mert; Yilmaz, Mehmet; Alpkaya, Alican Tuncay; Tuna, Merve; Akdeniz, Sevinc; Korkmaz, Nuray Can; Tosun, Aliye; Sahin, Serap Database covering the prayer movements which were not available previously Journal Article Scientific Data, 10 (1), 2023, (All Open Access, Gold Open Access, Green Open Access). @article{Mihcin2023, title = {Database covering the prayer movements which were not available previously}, author = {Senay Mihcin and Ahmet Mert Sahin and Mehmet Yilmaz and Alican Tuncay Alpkaya and Merve Tuna and Sevinc Akdeniz and Nuray Can Korkmaz and Aliye Tosun and Serap Sahin}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85159738866&doi=10.1038%2fs41597-023-02196-x&partnerID=40&md5=04869d265c2a00af6d7e25dad86d8231}, doi = {10.1038/s41597-023-02196-x}, year = {2023}, date = {2023-01-01}, journal = {Scientific Data}, volume = {10}, number = {1}, abstract = {Lower body implants are designed according to the boundary conditions of gait data and tested against. However, due to diversity in cultural backgrounds, religious rituals might cause different ranges of motion and different loading patterns. Especially in the Eastern part of the world, diverse Activities of Daily Living (ADL) consist of salat, yoga rituals, and different style sitting postures. A database covering these diverse activities of the Eastern world is non-existent. This study focuses on data collection protocol and the creation of an online database of previously excluded ADL activities, targeting 200 healthy subjects via Qualisys and IMU motion capture systems, and force plates, from West and Middle East Asian populations with a special focus on the lower body joints. The current version of the database covers 50 volunteers for 13 different activities. The tasks are defined and listed in a table to create a database to search based on age, gender, BMI, type of activity, and motion capture system. The collected data is to be used for designing implants to allow these sorts of activities to be performed. © 2023, The Author(s).}, note = {All Open Access, Gold Open Access, Green Open Access}, keywords = {}, pubstate = {published}, tppubtype = {article} } Lower body implants are designed according to the boundary conditions of gait data and tested against. However, due to diversity in cultural backgrounds, religious rituals might cause different ranges of motion and different loading patterns. Especially in the Eastern part of the world, diverse Activities of Daily Living (ADL) consist of salat, yoga rituals, and different style sitting postures. A database covering these diverse activities of the Eastern world is non-existent. This study focuses on data collection protocol and the creation of an online database of previously excluded ADL activities, targeting 200 healthy subjects via Qualisys and IMU motion capture systems, and force plates, from West and Middle East Asian populations with a special focus on the lower body joints. The current version of the database covers 50 volunteers for 13 different activities. The tasks are defined and listed in a table to create a database to search based on age, gender, BMI, type of activity, and motion capture system. The collected data is to be used for designing implants to allow these sorts of activities to be performed. © 2023, The Author(s). |
Alpkaya, Alican Tuncay; Mihcin, Senay Dynamic computational wear model of PEEK-on-XLPE bearing couple in total hip replacements Journal Article Medical Engineering and Physics, 117 , 2023. @article{Alpkaya2023, title = {Dynamic computational wear model of PEEK-on-XLPE bearing couple in total hip replacements}, author = {Alican Tuncay Alpkaya and Senay Mihcin}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85161750490&doi=10.1016%2fj.medengphy.2023.104006&partnerID=40&md5=37b73bc1035463a7dbadce39c74acb55}, doi = {10.1016/j.medengphy.2023.104006}, year = {2023}, date = {2023-01-01}, journal = {Medical Engineering and Physics}, volume = {117}, abstract = {Understanding wear mechanisms is a key factor to prevent primary failures causing revision surgery in total hip replacement (THR) applications. This study introduces a wear prediction model of (Polyetheretherketone) PEEK-on-XLPE (cross-linked polyethylene) bearing couple utilized to investigate the wear mechanism under 3D-gait cycle loading over 5 million cycles (Mc). A 32-mm PEEK femoral head and 4-mm thick XLPE bearing liner with a 3-mm PEEK shell are modeled in a 3D explicit finite element modeling (FEM) program. The volumetric and linear wear rates of XLPE liner per every million cycles were predicted as 1.965 mm3/Mc, and 0.0032 mm/Mc respectively. These results are consistent with the literature. PEEK-on-XLPE bearing couple exhibits a promising wear performance used in THR application. The wear pattern evolution of the model is similar to that of conventional polyethylene liners. Therefore, PEEK could be proposed as an alternative material to the CoCr head, especially used in XLPE-bearing couples. The wear prediction model could be utilized to improve the design parameters with the aim of prolonging the life span of hip implants. © 2023}, keywords = {}, pubstate = {published}, tppubtype = {article} } Understanding wear mechanisms is a key factor to prevent primary failures causing revision surgery in total hip replacement (THR) applications. This study introduces a wear prediction model of (Polyetheretherketone) PEEK-on-XLPE (cross-linked polyethylene) bearing couple utilized to investigate the wear mechanism under 3D-gait cycle loading over 5 million cycles (Mc). A 32-mm PEEK femoral head and 4-mm thick XLPE bearing liner with a 3-mm PEEK shell are modeled in a 3D explicit finite element modeling (FEM) program. The volumetric and linear wear rates of XLPE liner per every million cycles were predicted as 1.965 mm3/Mc, and 0.0032 mm/Mc respectively. These results are consistent with the literature. PEEK-on-XLPE bearing couple exhibits a promising wear performance used in THR application. The wear pattern evolution of the model is similar to that of conventional polyethylene liners. Therefore, PEEK could be proposed as an alternative material to the CoCr head, especially used in XLPE-bearing couples. The wear prediction model could be utilized to improve the design parameters with the aim of prolonging the life span of hip implants. © 2023 |
Torabnia, Shams; Mihcin, Senay; Lazoglu, Ismail Design and manufacturing of a hip joint motion simulator with a novel modular design approach Journal Article International Journal on Interactive Design and Manufacturing, 2023, (All Open Access, Green Open Access). @article{Torabnia2023, title = {Design and manufacturing of a hip joint motion simulator with a novel modular design approach}, author = {Shams Torabnia and Senay Mihcin and Ismail Lazoglu}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85171144946&doi=10.1007%2fs12008-023-01506-2&partnerID=40&md5=e978abee3f2263e3283041cbd26677ba}, doi = {10.1007/s12008-023-01506-2}, year = {2023}, date = {2023-01-01}, journal = {International Journal on Interactive Design and Manufacturing}, abstract = {The study is aimed to develop a hip joint wear simulator using a modular design approach to help experimentally monitor and control critical wear parameters to validate in-silico wear models. The proper control and application of wear parameters such as the range of motion, and the applied force values while estimating the lost material due to wear are essential for thorough analysis of wear phenomena for artificial joints. The simulator's dynamics were first modeled, then dynamic loading data was used to calculate the forces, which were further used for topology optimization to reduce the forces acting on each joint. The reduction of the link weights, connected to the actuators, intends to improve the quality of motion transferred to the femoral head. The modular design approach enables topology-optimized geometry, associated gravitational and dynamic forces, resulting in a cost-effective, energy-efficient product. Moreover, this design allows integration of the subject specific data by allowing different boundary conditions following the requirements of industry 5.0. Overall, the in-vitro motion stimulations of the hip-joint prosthesis and the modular design approach used in the study might help improve the accuracy and the effectiveness of wear simulations, which could lead into the development of better and longer-lasting joint prostheses for all. The subject-specific and society-based daily life data implemented as boundary conditions enable inclusion of the personalized effects. Next, with the results of the simulator, CEN Workshop Agreement (CWA) application is intended to cover the personalized effects for previously excluded populations, providing solution to inclusive design for all. © 2023, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.}, note = {All Open Access, Green Open Access}, keywords = {}, pubstate = {published}, tppubtype = {article} } The study is aimed to develop a hip joint wear simulator using a modular design approach to help experimentally monitor and control critical wear parameters to validate in-silico wear models. The proper control and application of wear parameters such as the range of motion, and the applied force values while estimating the lost material due to wear are essential for thorough analysis of wear phenomena for artificial joints. The simulator's dynamics were first modeled, then dynamic loading data was used to calculate the forces, which were further used for topology optimization to reduce the forces acting on each joint. The reduction of the link weights, connected to the actuators, intends to improve the quality of motion transferred to the femoral head. The modular design approach enables topology-optimized geometry, associated gravitational and dynamic forces, resulting in a cost-effective, energy-efficient product. Moreover, this design allows integration of the subject specific data by allowing different boundary conditions following the requirements of industry 5.0. Overall, the in-vitro motion stimulations of the hip-joint prosthesis and the modular design approach used in the study might help improve the accuracy and the effectiveness of wear simulations, which could lead into the development of better and longer-lasting joint prostheses for all. The subject-specific and society-based daily life data implemented as boundary conditions enable inclusion of the personalized effects. Next, with the results of the simulator, CEN Workshop Agreement (CWA) application is intended to cover the personalized effects for previously excluded populations, providing solution to inclusive design for all. © 2023, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature. |
Alpkaya, Alican Tuncay; Mihçin, Şenay The Computational Approach to Predicting Wear: Comparison of Wear Performance of CFR-PEEK and XLPE Liners in Total Hip Replacement Journal Article Tribology Transactions, 66 (1), pp. 59 – 72, 2023. @article{Alpkaya202359, title = {The Computational Approach to Predicting Wear: Comparison of Wear Performance of CFR-PEEK and XLPE Liners in Total Hip Replacement}, author = {Alican Tuncay Alpkaya and Şenay Mihçin}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85144145526&doi=10.1080%2f10402004.2022.2140727&partnerID=40&md5=727b9b4294502f860c17ec5352419b28}, doi = {10.1080/10402004.2022.2140727}, year = {2023}, date = {2023-01-01}, journal = {Tribology Transactions}, volume = {66}, number = {1}, pages = {59 – 72}, abstract = {Wear on articulating bearing surfaces is a key factor causing revision in total hip replacement (THR). Wear debris that releases particles from bearing surfaces might result in adverse soft tissue reactions requiring revision surgeries. In this study, a comprehensive computational wear model based on the Archard wear equation was performed to investigate the wear performance under a three-dimensional (3D) physiological gait cycle, mimicking a normal walking condition (5 million cycles). The study shows that the accuracy of the model is highly dependent on the mesh convergence, the wear fraction, and the scaling factor. The simulations were run to provide a vast amount of detail for the reproducibility of the work. Cobalt chromium (CoCr) on cross-linked polyethylene (XLPE) and CoCr on carbon-fiber-reinforced polyether ether ketone (CFR-PEEK) prototype models were created in silico. The volumetric wear rates for CoCr-on-XLPE were calculated as 0.2989 (Formula presented.) for CoCr head and 21.0271 (Formula presented.) for XLPE liner, while for CoCr-on-CFR-PEEK they were 0.3484 (Formula presented.) for CoCr head and 1.8476 (Formula presented.) for CFR-PEEK liner. When compared to in vivo and in vitro studies, the wear patterns of these two prototypes are consistent with those of the conventional polyethylene liners in the literature. Although the volumetric wear rate of the CFR-PEEK liner is about 11 times lower than the counterpart of XLPE in MoP implants, the wear rate of CoCr was higher when compared to its use with XLPE. Therefore, CFR-PEEK articulating against orthopaedic metals may not be as good an alternative as XLPE, due to higher indicative metallic wear. This detailed computational wear modeling methodology could be utilized in design improvements of implants. © 2022 Society of Tribologists and Lubrication Engineers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Wear on articulating bearing surfaces is a key factor causing revision in total hip replacement (THR). Wear debris that releases particles from bearing surfaces might result in adverse soft tissue reactions requiring revision surgeries. In this study, a comprehensive computational wear model based on the Archard wear equation was performed to investigate the wear performance under a three-dimensional (3D) physiological gait cycle, mimicking a normal walking condition (5 million cycles). The study shows that the accuracy of the model is highly dependent on the mesh convergence, the wear fraction, and the scaling factor. The simulations were run to provide a vast amount of detail for the reproducibility of the work. Cobalt chromium (CoCr) on cross-linked polyethylene (XLPE) and CoCr on carbon-fiber-reinforced polyether ether ketone (CFR-PEEK) prototype models were created in silico. The volumetric wear rates for CoCr-on-XLPE were calculated as 0.2989 (Formula presented.) for CoCr head and 21.0271 (Formula presented.) for XLPE liner, while for CoCr-on-CFR-PEEK they were 0.3484 (Formula presented.) for CoCr head and 1.8476 (Formula presented.) for CFR-PEEK liner. When compared to in vivo and in vitro studies, the wear patterns of these two prototypes are consistent with those of the conventional polyethylene liners in the literature. Although the volumetric wear rate of the CFR-PEEK liner is about 11 times lower than the counterpart of XLPE in MoP implants, the wear rate of CoCr was higher when compared to its use with XLPE. Therefore, CFR-PEEK articulating against orthopaedic metals may not be as good an alternative as XLPE, due to higher indicative metallic wear. This detailed computational wear modeling methodology could be utilized in design improvements of implants. © 2022 Society of Tribologists and Lubrication Engineers. |
2022 |
Yu, Hao; Feng, Zhihong; Wang, Ling; Mihcin, Senay; Kang, Jianfeng; Bai, Shizhu; Zhao, Yimin Finite Element Study of PEEK Materials Applied in Post-Retained Restorations Journal Article POLYMERS, 14 (16), 2022. @article{WOS:000846652600001, title = {Finite Element Study of PEEK Materials Applied in Post-Retained Restorations}, author = {Hao Yu and Zhihong Feng and Ling Wang and Senay Mihcin and Jianfeng Kang and Shizhu Bai and Yimin Zhao}, doi = {10.3390/polym14163422}, year = {2022}, date = {2022-08-01}, journal = {POLYMERS}, volume = {14}, number = {16}, abstract = {Background: This study aimed to investigate the biomechanical behaviors of polyether ether ketone (PEEK) and traditional materials (titanium and fiber) when used to restore tooth defects in the form of prefabricated post or customized post via computational modelling. Methods: First, the prototype of natural tooth, and the prototypes of prefabricated post and customized post were established, respectively, whilst the residual root was restored with dentin ferrule using reverse engineering methods. Then, the stress and strain of CFR-PEEK (PEEK reinforced by 30% carbon fiber) and pure PEEK (PEEK without any reprocessing) post were compared with those made in traditional materials using the three-dimensional finite element method. Results: From the stress point of view, compared with metal and fiber posts, CFR-PEEK and pure PEEK prefabricated post both demonstrated reduced post-core interface stress, post stress, post-root cement stress and root cement stress; moreover, CFR-PEEK and pure PEEK customized post demonstrated reduced post stress, post-root cement stress and root cement stress, while the strain of CFR-PEEK post was the closest to that of dentin. Conclusions: Compared with the traditional posts, both the CFR-PEEK and pure PEEK posts could reduce the risk of debonding and vertical root fracture, whether they were used as prefabricated posts or customized posts, but the biomechanical behavior of carbon fiber-reinforced CFR-PEEK restorations was the closest to dentin, no matter if they were used as prefabricated post or customized post. Therefore, the CFR-PEEK post could be more suitable to restore massive tooth defects. Pure PEEK needs filler reinforcement to be used for post-retained restoration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: This study aimed to investigate the biomechanical behaviors of polyether ether ketone (PEEK) and traditional materials (titanium and fiber) when used to restore tooth defects in the form of prefabricated post or customized post via computational modelling. Methods: First, the prototype of natural tooth, and the prototypes of prefabricated post and customized post were established, respectively, whilst the residual root was restored with dentin ferrule using reverse engineering methods. Then, the stress and strain of CFR-PEEK (PEEK reinforced by 30% carbon fiber) and pure PEEK (PEEK without any reprocessing) post were compared with those made in traditional materials using the three-dimensional finite element method. Results: From the stress point of view, compared with metal and fiber posts, CFR-PEEK and pure PEEK prefabricated post both demonstrated reduced post-core interface stress, post stress, post-root cement stress and root cement stress; moreover, CFR-PEEK and pure PEEK customized post demonstrated reduced post stress, post-root cement stress and root cement stress, while the strain of CFR-PEEK post was the closest to that of dentin. Conclusions: Compared with the traditional posts, both the CFR-PEEK and pure PEEK posts could reduce the risk of debonding and vertical root fracture, whether they were used as prefabricated posts or customized posts, but the biomechanical behavior of carbon fiber-reinforced CFR-PEEK restorations was the closest to dentin, no matter if they were used as prefabricated post or customized post. Therefore, the CFR-PEEK post could be more suitable to restore massive tooth defects. Pure PEEK needs filler reinforcement to be used for post-retained restoration. |
Mihcin, Senay BIOMEDICAL ENGINEERING-BIOMEDIZINISCHE TECHNIK, 67 (3), pp. 185-199, 2022. @article{WOS:000796085500001, title = {Simultaneous validation of wearable motion capture system for lower body applications: over single plane range of motion (ROM) and gait activities}, author = {Senay Mihcin}, doi = {10.1515/bmt-2021-0429}, year = {2022}, date = {2022-06-01}, journal = {BIOMEDICAL ENGINEERING-BIOMEDIZINISCHE TECHNIK}, volume = {67}, number = {3}, pages = {185-199}, abstract = {Extracting data from Zhu, 2019 #5 daily life activities is important in biomechanical applications to define exact boundary conditions for the intended use-based applications. Although optoelectronic camera-marker based systems are used as gold standard tools for medical applications, due to line-of-sight problem, there is a need for wearable, affordable motion capture (MOCAP) systems. We investigate the potential use of a wearable inertial measurement unit (IMU) based-wearable MOCAP system for biomechanical applications. The in vitro proof of concept is provided for the full lower body consisting of hip, knee, and ankle joints via controlled single-plane anatomical range of motion (ROM) simulations using an electrical motor, while collecting data simultaneously via opto-electronic markers and IMU sensors. On 15 healthy volunteers the flexion-extension, abduction-adduction, internal-external rotation (ROM) values of hip and, the flexion - extension ROM values of the knee and ankle joints are calculated for both systems. The Bland-Altman graphs showed promising agreement both for in vitro and in vivo experiments. The maximum Root Mean Square Errors (RMSE) between the systems in vitro was 3.4 degrees for hip and 5.9 degrees for knee flexion motion in vivo, respectively. The gait data of the volunteers were assessed between the heel strike and toe off events to investigate the limits of agreement, calculating the population averages and standard deviation for both systems over the gait cycle. The maximum difference was for the ankle joint <6 degrees. The results show that proposed system could be an option as an affordable-democratic solution.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Extracting data from Zhu, 2019 #5 daily life activities is important in biomechanical applications to define exact boundary conditions for the intended use-based applications. Although optoelectronic camera-marker based systems are used as gold standard tools for medical applications, due to line-of-sight problem, there is a need for wearable, affordable motion capture (MOCAP) systems. We investigate the potential use of a wearable inertial measurement unit (IMU) based-wearable MOCAP system for biomechanical applications. The in vitro proof of concept is provided for the full lower body consisting of hip, knee, and ankle joints via controlled single-plane anatomical range of motion (ROM) simulations using an electrical motor, while collecting data simultaneously via opto-electronic markers and IMU sensors. On 15 healthy volunteers the flexion-extension, abduction-adduction, internal-external rotation (ROM) values of hip and, the flexion - extension ROM values of the knee and ankle joints are calculated for both systems. The Bland-Altman graphs showed promising agreement both for in vitro and in vivo experiments. The maximum Root Mean Square Errors (RMSE) between the systems in vitro was 3.4 degrees for hip and 5.9 degrees for knee flexion motion in vivo, respectively. The gait data of the volunteers were assessed between the heel strike and toe off events to investigate the limits of agreement, calculating the population averages and standard deviation for both systems over the gait cycle. The maximum difference was for the ankle joint <6 degrees. The results show that proposed system could be an option as an affordable-democratic solution. |
Mihcin, Senay; Ciklacandir, Samet TOWARDS INTEGRATION OF THE FINITE ELEMENT MODELING TECHNIQUE INTO BIOMEDICAL ENGINEERING EDUCATION Journal Article BIOMEDICAL ENGINEERING-APPLICATIONS BASIS COMMUNICATIONS, 34 (02), 2022. @article{WOS:000786971300005, title = {TOWARDS INTEGRATION OF THE FINITE ELEMENT MODELING TECHNIQUE INTO BIOMEDICAL ENGINEERING EDUCATION}, author = {Senay Mihcin and Samet Ciklacandir}, doi = {10.4015/S101623722150054X}, year = {2022}, date = {2022-04-01}, journal = {BIOMEDICAL ENGINEERING-APPLICATIONS BASIS COMMUNICATIONS}, volume = {34}, number = {02}, abstract = {Biomedical engineering (BME) is a multidisciplinary field, resulting in a heavy course load from different fields. We hypothesize that, the engineering curriculum be tailored according to the requirements of the BME profession. In this study, we focus on the teaching of the finite element modeling (FEM) technique by redesigning the course to address the needs of the BME profession by some custom-made changes to meet the unmet. needs. After the completion of the course, evaluation methods of the students were analyzed and detailed over a survey providing feedback from the students. The surveys were related to the teaching the theory of FEM, the laboratory sessions, and the project sessions. The survey results were evaluated using statistical methods. The Pearson correlation coefficient showed a linear agreement between theoretical and practical sessions indicating efficient blending of skills because of the custom-made changes. The survey analysis showed that the students were in favour of the changes, allowing them to be more resourceful and confident with their skills. The positive results indicate a positive attitude among the students towards their profession. As the course design addresses the needs of the profession allowing students to fit in better, the students might, follow their own profession after graduation. A wider follow-up study might be planned next to compare the results between who received tailor-designed courses and those who did not.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomedical engineering (BME) is a multidisciplinary field, resulting in a heavy course load from different fields. We hypothesize that, the engineering curriculum be tailored according to the requirements of the BME profession. In this study, we focus on the teaching of the finite element modeling (FEM) technique by redesigning the course to address the needs of the BME profession by some custom-made changes to meet the unmet. needs. After the completion of the course, evaluation methods of the students were analyzed and detailed over a survey providing feedback from the students. The surveys were related to the teaching the theory of FEM, the laboratory sessions, and the project sessions. The survey results were evaluated using statistical methods. The Pearson correlation coefficient showed a linear agreement between theoretical and practical sessions indicating efficient blending of skills because of the custom-made changes. The survey analysis showed that the students were in favour of the changes, allowing them to be more resourceful and confident with their skills. The positive results indicate a positive attitude among the students towards their profession. As the course design addresses the needs of the profession allowing students to fit in better, the students might, follow their own profession after graduation. A wider follow-up study might be planned next to compare the results between who received tailor-designed courses and those who did not. |
Ciklacandir, S; Mihcin, S; Isler, Y IRBM, 43 (6), pp. 604-613, 2022. @article{Ciklacandir2022604, title = {Detailed Investigation of Three-Dimensional Modeling and Printing Technologies from Medical Images to Analyze Femoral Head Fractures Using Finite Element Analysis}, author = {S Ciklacandir and S Mihcin and Y Isler}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129883533&doi=10.1016%2fj.irbm.2022.04.005&partnerID=40&md5=31017add921b2693916e42e10bdb9b45}, doi = {10.1016/j.irbm.2022.04.005}, year = {2022}, date = {2022-01-01}, journal = {IRBM}, volume = {43}, number = {6}, pages = {604-613}, abstract = {Objectives: One of the fields, where additive manufacturing has numerous applications, is biomedical engineering. 3D printing is preferred over traditional manufacturing methodologies, mostly while developing subject-specific implants and medical devices. This study aims to provide a process flow detailing all the stages starting from the acquisition of radiological images from different imaging modalities; such as computed tomography (CT) and magnetic resonance imaging (MRI) to the printing of the bone morphology and finite element analysis; including the validation process. Materials & Methods: First, the CT scan of a lower abdomen area of a patient was converted into a 3D image using interactive medical imaging control system software. The segmentation process was applied to isolate the femoral head from the soft tissue and the pelvic bone. After the roughness errors and the gaps in the segments were removed using the 3Matic software, the file was converted to stereolithography (STL) file format to transfer to the 3D printer. The printing process was carried out via commercial powder-based Selective Laser Sintering (SLS) printer. The subject-specific femoral head model was formed in 3D. The Finite Element Analysis (FEA) of the femoral head was performed using a commercial FE software package. Results: The results show that experimental analysis and the CT scan-based FEA were compatible both for the stress distributions and the strain values as predicted by the models (R2=0.99). The deviation was calculated as approximately 12% between the experimental results and the Finite Element (FE) results. In addition, it was observed that the SLS technique produced useful results for modeling biomedical tissues with about 24x faster prototyping time. Conclusion: The prescribed process flow could be utilized in clinical settings for the pre-planning of the surgeries (≈428 minutes for femoral head) and also as an educational tool in the biomedical engineering field. © 2022 AGBM}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objectives: One of the fields, where additive manufacturing has numerous applications, is biomedical engineering. 3D printing is preferred over traditional manufacturing methodologies, mostly while developing subject-specific implants and medical devices. This study aims to provide a process flow detailing all the stages starting from the acquisition of radiological images from different imaging modalities; such as computed tomography (CT) and magnetic resonance imaging (MRI) to the printing of the bone morphology and finite element analysis; including the validation process. Materials & Methods: First, the CT scan of a lower abdomen area of a patient was converted into a 3D image using interactive medical imaging control system software. The segmentation process was applied to isolate the femoral head from the soft tissue and the pelvic bone. After the roughness errors and the gaps in the segments were removed using the 3Matic software, the file was converted to stereolithography (STL) file format to transfer to the 3D printer. The printing process was carried out via commercial powder-based Selective Laser Sintering (SLS) printer. The subject-specific femoral head model was formed in 3D. The Finite Element Analysis (FEA) of the femoral head was performed using a commercial FE software package. Results: The results show that experimental analysis and the CT scan-based FEA were compatible both for the stress distributions and the strain values as predicted by the models (R2=0.99). The deviation was calculated as approximately 12% between the experimental results and the Finite Element (FE) results. In addition, it was observed that the SLS technique produced useful results for modeling biomedical tissues with about 24x faster prototyping time. Conclusion: The prescribed process flow could be utilized in clinical settings for the pre-planning of the surgeries (≈428 minutes for femoral head) and also as an educational tool in the biomedical engineering field. © 2022 AGBM |
2021 |
Mihcin, Senay; Ciklacandir, Samet; Kocak, Mertcan; Tosun, Aliye Wearable Motion Capture System Evaluation for Biomechanical Studies for Hip Joints Journal Article JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, 143 (4), 2021. @article{WOS:000626080400016, title = {Wearable Motion Capture System Evaluation for Biomechanical Studies for Hip Joints}, author = {Senay Mihcin and Samet Ciklacandir and Mertcan Kocak and Aliye Tosun}, doi = {10.1115/1.4049199}, year = {2021}, date = {2021-04-01}, journal = {JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME}, volume = {143}, number = {4}, abstract = {Human motion capture (MOCAP) systems are vital while determining the loads occurring at the joints. Most of the clinical MOCAP systems are very costly, requiring investment and infrastructure. Therefore, alternative technologies are in demand. In this study, a novel markerless wearable MOCAP system was assessed for its compatibility with a biomechanical modeling software. To collect evidence, experiments were designed in two stages for quantifying the range of motion (ROM) of the hip joint, in vitro and in vivo. Three constrained single-plane motions-abduction/adduction, flexion/extension, and internal/external rotation movements of the active leg-were analyzed. The data were collected from 14 healthy volunteers, using the wearable system and a medical grade optoelectronic MOCAP system simultaneously and compared against. For the in vitro study, the root-mean-square error (RMSE) for the abduction/adduction motion of the hip joint was calculated as 0.11deg/0.30deg and 0.11deg/0.09deg, respectively, for the wearable and the opto-electronic system. The in vivo Bland-Altman plots showed that the two system data are comparable. The simulation software is found compatible to run the simulations in offline mode. The wearable system could be utilized in the field of biomechanics software for running the kinetic simulations. The results demonstrated that the wearable system could be an alternative in the field of biomechanics based on the evidence collected.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human motion capture (MOCAP) systems are vital while determining the loads occurring at the joints. Most of the clinical MOCAP systems are very costly, requiring investment and infrastructure. Therefore, alternative technologies are in demand. In this study, a novel markerless wearable MOCAP system was assessed for its compatibility with a biomechanical modeling software. To collect evidence, experiments were designed in two stages for quantifying the range of motion (ROM) of the hip joint, in vitro and in vivo. Three constrained single-plane motions-abduction/adduction, flexion/extension, and internal/external rotation movements of the active leg-were analyzed. The data were collected from 14 healthy volunteers, using the wearable system and a medical grade optoelectronic MOCAP system simultaneously and compared against. For the in vitro study, the root-mean-square error (RMSE) for the abduction/adduction motion of the hip joint was calculated as 0.11deg/0.30deg and 0.11deg/0.09deg, respectively, for the wearable and the opto-electronic system. The in vivo Bland-Altman plots showed that the two system data are comparable. The simulation software is found compatible to run the simulations in offline mode. The wearable system could be utilized in the field of biomechanics software for running the kinetic simulations. The results demonstrated that the wearable system could be an alternative in the field of biomechanics based on the evidence collected. |
Uzer-Yilmaz, B In vitro contact guidance of glioblastoma cells on metallic biomaterials Journal Article Journal of Materials Science: Materials in Medicine, 32 (4), 2021. @article{Uzer-Yilmaz2021, title = {In vitro contact guidance of glioblastoma cells on metallic biomaterials}, author = {B Uzer-Yilmaz}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103594796&doi=10.1007%2fs10856-021-06503-z&partnerID=40&md5=3df5859593f38e768004318b90d166df}, doi = {10.1007/s10856-021-06503-z}, year = {2021}, date = {2021-01-01}, journal = {Journal of Materials Science: Materials in Medicine}, volume = {32}, number = {4}, abstract = {Cancer cells’ ability to sense their microenvironment and interpret these signals for the regulation of directional adhesion plays crucial role in cancer invasion. Furthermore, given the established influence of mechanical properties of the substrate on cell behavior, the present study aims to elucidate the relationship between the contact guidance of glioblastoma cell (GBM) and evolution of microstructural and mechanical properties of the implants. SEM analyses of the specimens subjected to 5 and 25% of plastic strains revealed directional groove-like structures in micro and submicro-sizes, respectively. Microscale cytoplasmic protrusions of GBMs showed elongation favored along the grooves created via deformation markings on 5% deformed sample. Whereas filopodia, submicro-sized protrusions facilitating cancer invasion, elongated in the direction perpendicular to the deformation markings on the 25% deformed sample, which might lead to easy and rapid retraction. Furthermore, number of cell attachment was 1.7-fold greater on 25% deformed sample, where these cells showed the greatest cellular aspect ratio. The directional attachment and contact guidance of GBMs was reported for the first time on metallic implants and these findings propose the idea that GBM response could be regulated by controlling the spacing of the deformation markings, namely the degree of plastic deformation. These findings can be applied in the design of cell-instructive implants for therapeutic purposes to suppress cancer dissemination. [Figure not available: see fulltext.] © 2021, The Author(s).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cancer cells’ ability to sense their microenvironment and interpret these signals for the regulation of directional adhesion plays crucial role in cancer invasion. Furthermore, given the established influence of mechanical properties of the substrate on cell behavior, the present study aims to elucidate the relationship between the contact guidance of glioblastoma cell (GBM) and evolution of microstructural and mechanical properties of the implants. SEM analyses of the specimens subjected to 5 and 25% of plastic strains revealed directional groove-like structures in micro and submicro-sizes, respectively. Microscale cytoplasmic protrusions of GBMs showed elongation favored along the grooves created via deformation markings on 5% deformed sample. Whereas filopodia, submicro-sized protrusions facilitating cancer invasion, elongated in the direction perpendicular to the deformation markings on the 25% deformed sample, which might lead to easy and rapid retraction. Furthermore, number of cell attachment was 1.7-fold greater on 25% deformed sample, where these cells showed the greatest cellular aspect ratio. The directional attachment and contact guidance of GBMs was reported for the first time on metallic implants and these findings propose the idea that GBM response could be regulated by controlling the spacing of the deformation markings, namely the degree of plastic deformation. These findings can be applied in the design of cell-instructive implants for therapeutic purposes to suppress cancer dissemination. [Figure not available: see fulltext.] © 2021, The Author(s). |
2020 |
Uzer, B Frontiers in Materials, 7 , 2020. @article{Uzer2020, title = {Modulating the Surface Properties of Metallic Implants and the Response of Breast Cancer Cells by Surface Relief Induced via Bulk Plastic Deformation}, author = {B Uzer}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085159761&doi=10.3389%2ffmats.2020.00099&partnerID=40&md5=74ced050c4b670609a1e8bf00f28b1b7}, doi = {10.3389/fmats.2020.00099}, year = {2020}, date = {2020-01-01}, journal = {Frontiers in Materials}, volume = {7}, abstract = {Micro/nanoscale textured surfaces have presented promising tissue–implant integration via increasing surface roughness, energy, and wettability. Recent studies indicate that surface texture imparted on the metallic implants via surface relief induced with simple bulk plastic deformation methods (e.g., tension or compression tests) does result in enhanced cell response. Considering these recent findings, this study presents a thorough investigation of the effects of surface relief on surface properties of implants and cell adhesion. Experiments are conducted on the samples subjected to interrupted tensile tests up to the plastic strains of 5, 15, 25, and 35%. Main findings from these experiments suggest that, as the plastic deformation level increases up to 35% from the undeformed (control) level, (1) average surface roughness (Ra) increases from 17.58 to 595.29 nm; (2) water contact angle decreases from 84.28 to 58.07°; (3) surface free energy (SFE) increases from 36.06 to 48.89 mJ/m2; and (4) breast cancer cells show 2.4-fold increased number of attachment. Increased surface roughness indicates the distorted topography via surface relief and leads to increased wettability, consistent with Wenzel’s theory. The higher levels of SFE observed were related to high-energy regions provided via activation of strengthening mechanisms, which increased in volume fraction concomitant with plastic deformation. Eventually, the displayed improvements in surface properties have increased the number of breast cancer cell attachments. These findings indicate that surface relief induced upon plastic deformation processes could be utilized in the design of implants for therapeutic or diagnostic purposes through capturing breast cancer cells on the material surface. © Copyright © 2020 Uzer.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Micro/nanoscale textured surfaces have presented promising tissue–implant integration via increasing surface roughness, energy, and wettability. Recent studies indicate that surface texture imparted on the metallic implants via surface relief induced with simple bulk plastic deformation methods (e.g., tension or compression tests) does result in enhanced cell response. Considering these recent findings, this study presents a thorough investigation of the effects of surface relief on surface properties of implants and cell adhesion. Experiments are conducted on the samples subjected to interrupted tensile tests up to the plastic strains of 5, 15, 25, and 35%. Main findings from these experiments suggest that, as the plastic deformation level increases up to 35% from the undeformed (control) level, (1) average surface roughness (Ra) increases from 17.58 to 595.29 nm; (2) water contact angle decreases from 84.28 to 58.07°; (3) surface free energy (SFE) increases from 36.06 to 48.89 mJ/m2; and (4) breast cancer cells show 2.4-fold increased number of attachment. Increased surface roughness indicates the distorted topography via surface relief and leads to increased wettability, consistent with Wenzel’s theory. The higher levels of SFE observed were related to high-energy regions provided via activation of strengthening mechanisms, which increased in volume fraction concomitant with plastic deformation. Eventually, the displayed improvements in surface properties have increased the number of breast cancer cell attachments. These findings indicate that surface relief induced upon plastic deformation processes could be utilized in the design of implants for therapeutic or diagnostic purposes through capturing breast cancer cells on the material surface. © Copyright © 2020 Uzer. |
2018 |
Uzer, B; Picak, S; Liu, J; Jozaghi, T; Canadinc, D; Karaman, I; Chumlyakov, Y I; Kireeva, I On the mechanical response and microstructure evolution of NiCoCr single crystalline medium entropy alloys Journal Article Materials Research Letters, 6 (8), pp. 442-449, 2018. @article{Uzer2018442, title = {On the mechanical response and microstructure evolution of NiCoCr single crystalline medium entropy alloys}, author = {B Uzer and S Picak and J Liu and T Jozaghi and D Canadinc and I Karaman and Y I Chumlyakov and I Kireeva}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048308085&doi=10.1080%2f21663831.2018.1478331&partnerID=40&md5=fdf9a8d03d121110bc0c015c525b5373}, doi = {10.1080/21663831.2018.1478331}, year = {2018}, date = {2018-01-01}, journal = {Materials Research Letters}, volume = {6}, number = {8}, pages = {442-449}, abstract = {Unusual strain hardening response and ductility of NiCoCr equiatomic alloy were investigated through microstructural analysis of [111], [110] and [123] single crystals deformed under tension. Nano-twinning prevailed at, as early as, 4% strain along the [110] orientation, providing a steady work hardening, and thereby a significant ductility. While single slip dominated in the [123] orientation at the early stages of deformation, multiple slip and nanotwinning was prominent in the [111] orientation. Significant dislocation storage capability and resistance to necking due to nanotwinning provided unprecedented ductility to NiCoCr medium entropy alloys, making it superior than quinary variants, and conventional low and medium stacking fault energy steels. IMPACT STATEMENT: A comparison of the current results on the ternary medium entropy alloy single crystals and those previously reported on the quinary and quaternary fcc equiatomic alloys demonstrates that a higher configurational entropy does not necessarily warrant improved mechanical properties. © 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Unusual strain hardening response and ductility of NiCoCr equiatomic alloy were investigated through microstructural analysis of [111], [110] and [123] single crystals deformed under tension. Nano-twinning prevailed at, as early as, 4% strain along the [110] orientation, providing a steady work hardening, and thereby a significant ductility. While single slip dominated in the [123] orientation at the early stages of deformation, multiple slip and nanotwinning was prominent in the [111] orientation. Significant dislocation storage capability and resistance to necking due to nanotwinning provided unprecedented ductility to NiCoCr medium entropy alloys, making it superior than quinary variants, and conventional low and medium stacking fault energy steels. IMPACT STATEMENT: A comparison of the current results on the ternary medium entropy alloy single crystals and those previously reported on the quinary and quaternary fcc equiatomic alloys demonstrates that a higher configurational entropy does not necessarily warrant improved mechanical properties. © 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. |
Canadinc, D; Uzer, B; Elmadagli, M; Guner, F Nanotwin Formation in High-Manganese Austenitic Steels Under Explosive Shock Loading Journal Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 49 (4), pp. 1026-1030, 2018. @article{Canadinc20181026, title = {Nanotwin Formation in High-Manganese Austenitic Steels Under Explosive Shock Loading}, author = {D Canadinc and B Uzer and M Elmadagli and F Guner}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041919869&doi=10.1007%2fs11661-018-4510-x&partnerID=40&md5=a874b8da4c563aa0e96e5e788ad81251}, doi = {10.1007/s11661-018-4510-x}, year = {2018}, date = {2018-01-01}, journal = {Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science}, volume = {49}, number = {4}, pages = {1026-1030}, abstract = {The micro-deformation mechanisms active in a high-manganese austenitic steel were investigated upon explosive shock loading. Single system of nanotwins forming within primary twins were shown to govern the deformation despite the elevated temperatures attained during testing. The benefits of nanotwin formation for potential armor materials were demonstrated. © 2018, The Minerals, Metals & Materials Society and ASM International.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The micro-deformation mechanisms active in a high-manganese austenitic steel were investigated upon explosive shock loading. Single system of nanotwins forming within primary twins were shown to govern the deformation despite the elevated temperatures attained during testing. The benefits of nanotwin formation for potential armor materials were demonstrated. © 2018, The Minerals, Metals & Materials Society and ASM International. |
Uzer, B; Canadinc, D The effect of plastic deformation on the cell viability and adhesion behavior in metallic implant materials Journal Article Ceramic Transactions, 261 , pp. 187-196, 2018. @article{Uzer2018187, title = {The effect of plastic deformation on the cell viability and adhesion behavior in metallic implant materials}, author = {B Uzer and D Canadinc}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055448117&doi=10.1002%2f9781119423829.ch16&partnerID=40&md5=3e385fa138796826206feff61faaf2f2}, doi = {10.1002/9781119423829.ch16}, year = {2018}, date = {2018-01-01}, journal = {Ceramic Transactions}, volume = {261}, pages = {187-196}, abstract = {The adhesion and spreading behavior, and viability of the brain tumor and fibroblast cells were analyzed on the austenitic 316L stainless steel samples, which were deformed to different strains, promoting varying degrees of plastic deformation activities. Surface characterization and microscopy analyses showed that increasing plastic deformation significantly altered surface topography by the formation of surface extrusions and grooves, which increased the surface roughness. In addition, twinning and slip mechanisms created regions with high surface energy which catalyzed the adhesion of tCM proteins and formation of focal contacts. Specifically, tumor cells exhibited a greater viability and adhesion behavior on the samples deformed to the largest plastic strains concomitant with the filopodial extensions, which showed the higher affinity of these cells on the deformed samples. Conversely, fibroblast cells did not exhibit enhanced cell response on the deformed samples, which can stem from the surface roughness, size of the cells or the failure of the adhesion of tCM molecules expressed by the fibroblast cells. The current results show that surface and microstructural properties of the implants can be tailored by the activation of plastic deformation mechanisms to obtain ideal materials specific to body location and treatment. © 2017 The American Ceramic Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The adhesion and spreading behavior, and viability of the brain tumor and fibroblast cells were analyzed on the austenitic 316L stainless steel samples, which were deformed to different strains, promoting varying degrees of plastic deformation activities. Surface characterization and microscopy analyses showed that increasing plastic deformation significantly altered surface topography by the formation of surface extrusions and grooves, which increased the surface roughness. In addition, twinning and slip mechanisms created regions with high surface energy which catalyzed the adhesion of tCM proteins and formation of focal contacts. Specifically, tumor cells exhibited a greater viability and adhesion behavior on the samples deformed to the largest plastic strains concomitant with the filopodial extensions, which showed the higher affinity of these cells on the deformed samples. Conversely, fibroblast cells did not exhibit enhanced cell response on the deformed samples, which can stem from the surface roughness, size of the cells or the failure of the adhesion of tCM molecules expressed by the fibroblast cells. The current results show that surface and microstructural properties of the implants can be tailored by the activation of plastic deformation mechanisms to obtain ideal materials specific to body location and treatment. © 2017 The American Ceramic Society. |
2017 |
Mihcin, Senay; Karakitsios, Ioannis; Le, Nhan; Strehlow, Jan; Demedts, Daniel; Schwenke, Michael; Haase, Sabrina; Preusser, Tobias; Melzer, Andreas Methodology on quantification of sonication duration for safe application of MR guided focused ultrasound for liver tumour ablation Journal Article COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE, 152 , pp. 125-130, 2017, ISSN: 0169-2607. @article{ISI:000413258300013, title = {Methodology on quantification of sonication duration for safe application of MR guided focused ultrasound for liver tumour ablation}, author = {Senay Mihcin and Ioannis Karakitsios and Nhan Le and Jan Strehlow and Daniel Demedts and Michael Schwenke and Sabrina Haase and Tobias Preusser and Andreas Melzer}, doi = {10.1016/j.cmpb.2017.09.006}, issn = {0169-2607}, year = {2017}, date = {2017-12-01}, journal = {COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE}, volume = {152}, pages = {125-130}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Schwenke, Michael; Strehlow, Jan; Demedts, Daniel; Haase, Sabrina; Romero, Diego Barrios; Rothluebbers, Sven; von Dresky, Caroline; Zidowitz, Stephan; Georgii, Joachim; Mihcin, Senay; Bezzi, Mario; Tanner, Christine; Sat, Giora; Levy, Yoav; Jenne, Juergen; Guenther, Matthias; Melzer, Andreas; Preusser, Tobias A focused ultrasound treatment system for moving targets (part I): generic system design and in-silico first-stage evaluation Journal Article JOURNAL OF THERAPEUTIC ULTRASOUND, 5 , pp. 1-14, 2017, ISSN: 2050-5736. @article{ISI:000406663900001, title = {A focused ultrasound treatment system for moving targets (part I): generic system design and in-silico first-stage evaluation}, author = {Michael Schwenke and Jan Strehlow and Daniel Demedts and Sabrina Haase and Diego Barrios Romero and Sven Rothluebbers and Caroline von Dresky and Stephan Zidowitz and Joachim Georgii and Senay Mihcin and Mario Bezzi and Christine Tanner and Giora Sat and Yoav Levy and Juergen Jenne and Matthias Guenther and Andreas Melzer and Tobias Preusser}, doi = {10.1186/s40349-017-0098-7}, issn = {2050-5736}, year = {2017}, date = {2017-07-01}, journal = {JOURNAL OF THERAPEUTIC ULTRASOUND}, volume = {5}, pages = {1-14}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Karakitsios, Ioannis; Joy, Joyce; Mihcin, Senay; Melzer, Andreas Acoustic characterization of Thiel liver for magnetic resonance-guided focused ultrasound treatment Journal Article MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES, 26 (2), pp. 92-96, 2017, ISSN: 1364-5706. @article{ISI:000398127600005, title = {Acoustic characterization of Thiel liver for magnetic resonance-guided focused ultrasound treatment}, author = {Ioannis Karakitsios and Joyce Joy and Senay Mihcin and Andreas Melzer}, doi = {10.1080/13645706.2016.1253589}, issn = {1364-5706}, year = {2017}, date = {2017-01-01}, journal = {MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES}, volume = {26}, number = {2}, pages = {92-96}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Uzer, B; Birer, O; Canadinc, D Investigation of the Dissolution–Reformation Cycle of the Passive Oxide Layer on NiTi Orthodontic Archwires Journal Article Shape Memory and Superelasticity, 3 (3), pp. 264-273, 2017. @article{Uzer2017264, title = {Investigation of the Dissolution–Reformation Cycle of the Passive Oxide Layer on NiTi Orthodontic Archwires}, author = {B Uzer and O Birer and D Canadinc}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070886170&doi=10.1007%2fs40830-017-0114-3&partnerID=40&md5=c157896a2009c27ea7f0b8b4c8b5c33c}, doi = {10.1007/s40830-017-0114-3}, year = {2017}, date = {2017-01-01}, journal = {Shape Memory and Superelasticity}, volume = {3}, number = {3}, pages = {264-273}, abstract = {Dissolution–reformation cycle of the passive oxide layer on the nickel–titanium (NiTi) orthodontic archwires was investigated, which has recently been recognized as one of the key parameters dictating the biocompatibility of archwires. Specifically, commercially available NiTi orthodontic archwires were immersed in artificial saliva solutions of different pH values (2.3, 3.3, and 4.3) for four different immersion periods: 1, 7, 14, and 30 days. Characterization of the virgin and tested samples revealed that the titanium oxide layer on the NiTi archwire surfaces exhibit a dissolution–reformation cycle within the first 14 days of the immersion period: the largest amount of Ni ion release occurred within the first week of immersion, while it significantly decreased during the reformation period from day 7 to day 14. Furthermore, the oxide layer reformation was catalyzed on the grooves within the peaks and valleys due to relatively larger surface energy of these regions, which eventually decreased the surface roughness significantly within the reformation period. Overall, the current results clearly demonstrate that the analyses of dissolution–reformation cycle of the oxide layer in orthodontic archwires, surface roughness, and ion release behavior constitute utmost importance in order to ensure both the highest degree of biocompatibility and an efficient medical treatment. © 2017, ASM International.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Dissolution–reformation cycle of the passive oxide layer on the nickel–titanium (NiTi) orthodontic archwires was investigated, which has recently been recognized as one of the key parameters dictating the biocompatibility of archwires. Specifically, commercially available NiTi orthodontic archwires were immersed in artificial saliva solutions of different pH values (2.3, 3.3, and 4.3) for four different immersion periods: 1, 7, 14, and 30 days. Characterization of the virgin and tested samples revealed that the titanium oxide layer on the NiTi archwire surfaces exhibit a dissolution–reformation cycle within the first 14 days of the immersion period: the largest amount of Ni ion release occurred within the first week of immersion, while it significantly decreased during the reformation period from day 7 to day 14. Furthermore, the oxide layer reformation was catalyzed on the grooves within the peaks and valleys due to relatively larger surface energy of these regions, which eventually decreased the surface roughness significantly within the reformation period. Overall, the current results clearly demonstrate that the analyses of dissolution–reformation cycle of the oxide layer in orthodontic archwires, surface roughness, and ion release behavior constitute utmost importance in order to ensure both the highest degree of biocompatibility and an efficient medical treatment. © 2017, ASM International. |
2016 |
Mihcin, Senay Spinal curvature for the assessment of spinal stability Journal Article INTERNATIONAL JOURNAL OF BIOMEDICAL ENGINEERING AND TECHNOLOGY, 20 (3), pp. 226-242, 2016, ISSN: 1752-6418. @article{ISI:000384710300003, title = {Spinal curvature for the assessment of spinal stability}, author = {Senay Mihcin}, doi = {10.1504/IJBET.2016.075425}, issn = {1752-6418}, year = {2016}, date = {2016-01-01}, journal = {INTERNATIONAL JOURNAL OF BIOMEDICAL ENGINEERING AND TECHNOLOGY}, volume = {20}, number = {3}, pages = {226-242}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Karakitsios, Ioannis; Mihcin, Senay; Saliev, Timur; Melzer, Andreas Feasibility study of pre-clinical Thiel embalmed human cadaver for MR-guided focused ultrasound of the spine Journal Article MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES, 25 (3), pp. 154-161, 2016, ISSN: 1364-5706. @article{ISI:000383343900006, title = {Feasibility study of pre-clinical Thiel embalmed human cadaver for MR-guided focused ultrasound of the spine}, author = {Ioannis Karakitsios and Senay Mihcin and Timur Saliev and Andreas Melzer}, doi = {10.3109/13645706.2016.1150297}, issn = {1364-5706}, year = {2016}, date = {2016-01-01}, journal = {MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES}, volume = {25}, number = {3}, pages = {154-161}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Uzer, B; Toker, S M; Cingoz, A; Bagci-Onder, T; Gerstein, G; Maier, H J; Canadinc, D An exploration of plastic deformation dependence of cell viability and adhesion in metallic implant materials Journal Article Journal of the Mechanical Behavior of Biomedical Materials, 60 , pp. 177-186, 2016. @article{Uzer2016177, title = {An exploration of plastic deformation dependence of cell viability and adhesion in metallic implant materials}, author = {B Uzer and S M Toker and A Cingoz and T Bagci-Onder and G Gerstein and H J Maier and D Canadinc}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955118639&doi=10.1016%2fj.jmbbm.2016.01.001&partnerID=40&md5=93dcdcf6f5350d917e906984b75d9693}, doi = {10.1016/j.jmbbm.2016.01.001}, year = {2016}, date = {2016-01-01}, journal = {Journal of the Mechanical Behavior of Biomedical Materials}, volume = {60}, pages = {177-186}, abstract = {The relationship between cell viability and adhesion behavior, and micro-deformation mechanisms was investigated on austenitic 316L stainless steel samples, which were subjected to different amounts of plastic strains (5%, 15%, 25%, 35% and 60%) to promote a variety in the slip and twin activities in the microstructure. Confocal laser scanning microscopy (CLSM) and field emission scanning electron microscopy (FESEM) revealed that cells most favored the samples with the largest plastic deformation, such that they spread more and formed significant filopodial extensions. Specifically, brain tumor cells seeded on the 35% deformed samples exhibited the best adhesion performance, where a significant slip activity was prevalent, accompanied by considerable slip-twin interactions. Furthermore, maximum viability was exhibited by the cells seeded on the 60% deformed samples, which were particularly designed in a specific geometry that could endure greater strain values. Overall, the current findings open a new venue for the production of metallic implants with enhanced biocompatibility, such that the adhesion and viability of the cells surrounding an implant can be optimized by tailoring the surface relief of the material, which is dictated by the micro-deformation mechanism activities facilitated by plastic deformation imposed by machining. © 2016 Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The relationship between cell viability and adhesion behavior, and micro-deformation mechanisms was investigated on austenitic 316L stainless steel samples, which were subjected to different amounts of plastic strains (5%, 15%, 25%, 35% and 60%) to promote a variety in the slip and twin activities in the microstructure. Confocal laser scanning microscopy (CLSM) and field emission scanning electron microscopy (FESEM) revealed that cells most favored the samples with the largest plastic deformation, such that they spread more and formed significant filopodial extensions. Specifically, brain tumor cells seeded on the 35% deformed samples exhibited the best adhesion performance, where a significant slip activity was prevalent, accompanied by considerable slip-twin interactions. Furthermore, maximum viability was exhibited by the cells seeded on the 60% deformed samples, which were particularly designed in a specific geometry that could endure greater strain values. Overall, the current findings open a new venue for the production of metallic implants with enhanced biocompatibility, such that the adhesion and viability of the cells surrounding an implant can be optimized by tailoring the surface relief of the material, which is dictated by the micro-deformation mechanism activities facilitated by plastic deformation imposed by machining. © 2016 Elsevier Ltd. |
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Alpkaya, Alican Tuncay; Mihcin, Senay The Computational Approach to Predicting Wear: Comparison of Wear Performance of CFR-PEEK and XLPE Liners in Total Hip Replacement Journal Article TRIBOLOGY TRANSACTIONS, 0000. @article{WOS:000899732300001, title = {The Computational Approach to Predicting Wear: Comparison of Wear Performance of CFR-PEEK and XLPE Liners in Total Hip Replacement}, author = {Alican Tuncay Alpkaya and Senay Mihcin}, doi = {10.1080/10402004.2022.2140727}, journal = {TRIBOLOGY TRANSACTIONS}, abstract = {Wear on articulating bearing surfaces is a key factor causing revision in total hip replacement (THR). Wear debris that releases particles from bearing surfaces might result in adverse soft tissue reactions requiring revision surgeries. In this study, a comprehensive computational wear model based on the Archard wear equation was performed to investigate the wear performance under a three-dimensional (3D) physiological gait cycle, mimicking a normal walking condition (5 million cycles). The study shows that the accuracy of the model is highly dependent on the mesh convergence, the wear fraction, and the scaling factor. The simulations were run to provide a vast amount of detail for the reproducibility of the work. Cobalt chromium (CoCr) on cross-linked polyethylene (XLPE) and CoCr on carbon-fiber-reinforced polyether ether ketone (CFR-PEEK) prototype models were created in silico. The volumetric wear rates for CoCr-on-XLPE were calculated as 0.2989 mm(3)/year for CoCr head and 21.0271 mm(3)/year for XLPE liner, while for CoCr-on-CFR-PEEK they were 0.3484 mm(3)/year for CoCr head and 1.8476 mm(3)/year for CFR-PEEK liner. When compared to in vivo and in vitro studies, the wear patterns of these two prototypes are consistent with those of the conventional polyethylene liners in the literature. Although the volumetric wear rate of the CFR-PEEK liner is about 11 times lower than the counterpart of XLPE in MoP implants, the wear rate of CoCr was higher when compared to its use with XLPE. Therefore, CFR-PEEK articulating against orthopatextbackslashedic metals may not be as good an alternative as XLPE, due to higher indicative metallic wear. This detailed computational wear modeling methodology could be utilized in design improvements of implants.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Wear on articulating bearing surfaces is a key factor causing revision in total hip replacement (THR). Wear debris that releases particles from bearing surfaces might result in adverse soft tissue reactions requiring revision surgeries. In this study, a comprehensive computational wear model based on the Archard wear equation was performed to investigate the wear performance under a three-dimensional (3D) physiological gait cycle, mimicking a normal walking condition (5 million cycles). The study shows that the accuracy of the model is highly dependent on the mesh convergence, the wear fraction, and the scaling factor. The simulations were run to provide a vast amount of detail for the reproducibility of the work. Cobalt chromium (CoCr) on cross-linked polyethylene (XLPE) and CoCr on carbon-fiber-reinforced polyether ether ketone (CFR-PEEK) prototype models were created in silico. The volumetric wear rates for CoCr-on-XLPE were calculated as 0.2989 mm(3)/year for CoCr head and 21.0271 mm(3)/year for XLPE liner, while for CoCr-on-CFR-PEEK they were 0.3484 mm(3)/year for CoCr head and 1.8476 mm(3)/year for CFR-PEEK liner. When compared to in vivo and in vitro studies, the wear patterns of these two prototypes are consistent with those of the conventional polyethylene liners in the literature. Although the volumetric wear rate of the CFR-PEEK liner is about 11 times lower than the counterpart of XLPE in MoP implants, the wear rate of CoCr was higher when compared to its use with XLPE. Therefore, CFR-PEEK articulating against orthopatextbackslashedic metals may not be as good an alternative as XLPE, due to higher indicative metallic wear. This detailed computational wear modeling methodology could be utilized in design improvements of implants. |
Alpkaya, Alican Tuncay; Mihcin, Senay The Computational Approach to Predicting Wear: Comparison of Wear Performance of CFR-PEEK and XLPE Liners in Total Hip Replacement Journal Article TRIBOLOGY TRANSACTIONS, 0000. @article{WOS:000899732300001b, title = {The Computational Approach to Predicting Wear: Comparison of Wear Performance of CFR-PEEK and XLPE Liners in Total Hip Replacement}, author = {Alican Tuncay Alpkaya and Senay Mihcin}, doi = {10.1080/10402004.2022.2140727}, journal = {TRIBOLOGY TRANSACTIONS}, abstract = {Wear on articulating bearing surfaces is a key factor causing revision in total hip replacement (THR). Wear debris that releases particles from bearing surfaces might result in adverse soft tissue reactions requiring revision surgeries. In this study, a comprehensive computational wear model based on the Archard wear equation was performed to investigate the wear performance under a three-dimensional (3D) physiological gait cycle, mimicking a normal walking condition (5 million cycles). The study shows that the accuracy of the model is highly dependent on the mesh convergence, the wear fraction, and the scaling factor. The simulations were run to provide a vast amount of detail for the reproducibility of the work. Cobalt chromium (CoCr) on cross-linked polyethylene (XLPE) and CoCr on carbon-fiber-reinforced polyether ether ketone (CFR-PEEK) prototype models were created in silico. The volumetric wear rates for CoCr-on-XLPE were calculated as 0.2989 mm(3)/year for CoCr head and 21.0271 mm(3)/year for XLPE liner, while for CoCr-on-CFR-PEEK they were 0.3484 mm(3)/year for CoCr head and 1.8476 mm(3)/year for CFR-PEEK liner. When compared to in vivo and in vitro studies, the wear patterns of these two prototypes are consistent with those of the conventional polyethylene liners in the literature. Although the volumetric wear rate of the CFR-PEEK liner is about 11 times lower than the counterpart of XLPE in MoP implants, the wear rate of CoCr was higher when compared to its use with XLPE. Therefore, CFR-PEEK articulating against orthopatextbackslashedic metals may not be as good an alternative as XLPE, due to higher indicative metallic wear. This detailed computational wear modeling methodology could be utilized in design improvements of implants.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Wear on articulating bearing surfaces is a key factor causing revision in total hip replacement (THR). Wear debris that releases particles from bearing surfaces might result in adverse soft tissue reactions requiring revision surgeries. In this study, a comprehensive computational wear model based on the Archard wear equation was performed to investigate the wear performance under a three-dimensional (3D) physiological gait cycle, mimicking a normal walking condition (5 million cycles). The study shows that the accuracy of the model is highly dependent on the mesh convergence, the wear fraction, and the scaling factor. The simulations were run to provide a vast amount of detail for the reproducibility of the work. Cobalt chromium (CoCr) on cross-linked polyethylene (XLPE) and CoCr on carbon-fiber-reinforced polyether ether ketone (CFR-PEEK) prototype models were created in silico. The volumetric wear rates for CoCr-on-XLPE were calculated as 0.2989 mm(3)/year for CoCr head and 21.0271 mm(3)/year for XLPE liner, while for CoCr-on-CFR-PEEK they were 0.3484 mm(3)/year for CoCr head and 1.8476 mm(3)/year for CFR-PEEK liner. When compared to in vivo and in vitro studies, the wear patterns of these two prototypes are consistent with those of the conventional polyethylene liners in the literature. Although the volumetric wear rate of the CFR-PEEK liner is about 11 times lower than the counterpart of XLPE in MoP implants, the wear rate of CoCr was higher when compared to its use with XLPE. Therefore, CFR-PEEK articulating against orthopatextbackslashedic metals may not be as good an alternative as XLPE, due to higher indicative metallic wear. This detailed computational wear modeling methodology could be utilized in design improvements of implants. |
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