Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
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Article Citation - WoS: 2Citation - Scopus: 3Design and Manufacturing of a Hip Joint Motion Simulator With a Novel Modular Design Approach(Springer, 2023) Torabnia, Shams; Mihçin, Şenay; Lazoğlu, İsmailThe 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.Data Paper Citation - WoS: 15Citation - Scopus: 20Database Covering the Prayer Movements Which Were Not Available Previously(Nature Publishing Group, 2023) Mihçin, Şenay; Şahin, Ahmet Mert; Yılmaz, Mehmet; Alpkaya, Alican Tuncay; Tuna, Merve; Akdeniz, Sevinç; Can, Nuray Korkmaz; Tosun, Aliye; Şahin, SerapLower 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.Data Paper Database Covering the Previously Excluded Daily Life Activities(2023) Mihçin, Şenay; Şahin, Ahmet Mert; Yılmaz, Mehmet; Alpkaya, Alican Tuncay; Tuna, Merve; Can, Nuray Korkmaz; Şahin, Serap; Akdeniz, Sevinç; Tosun, AliyeIn biomedical engineering, 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. Although databases cover ADL for the Western population, a database covering these diverse activities of the Eastern world, specific to these populations is non-existent. To include previously excluded ADL is a key step in understanding the kinematics and kinetics of these activities. By means of developments in motion capture technologies, excluded ADL data are captured to obtain the coordinate values to calculate the range of motion and the joint reaction forces. 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. Anthropometrics are known to affect kinematics and kinetics which are also included in the collected data. The current version of the database covers 50 volunteers for 12 different activities, the database aims for 100- male and 100- female healthy volunteers as the final target including C3D and BVH file types. The tasks are defined and listed in a table to create a database to make a query based on age, gender, BMI, type of activity and motion capture system. The data is collected only from a healthy population to understand healthy motion patterns during these previously excluded ADLs. The collected data is to be used for designing implants to allow these sorts of activities to be performed without compromising the quality of life of patients performing these activities in the future.Conference Object Development of a Force Sensor for Biomechanical Simulations of a Cycling Activity(IEEE, 2022) Karacaoğlu, Bilal; Şahin, Ahmet Mert; Çıklaçandır, Samet; Yılmaz, Mehmet; Mihçin, ŞenayKnowing the forces applied to the pedals during a cycling activity is of great importance in the field of biomechanics when calculating the loads acting on the joints. A load cell-based force sensor was designed for this purpose since the force plate fixed to the floor in gait laboratories cannot be used to measure the reaction forces on the bicycle pedal due to physical constraints. To investigate the accuracy and precision of the force plate, a two-stage experiment, static and dynamic force measurement tests were designed. First, the first static measurements were carried out with standard loads of 1000 g, 1200 g, 1500 g. To understand the behavior of the sensors under dynamic loading, dynamic measurements were conducted while the designed force sensor is attached to the bike pedal while using a commercially available power meter simultaneously to cross-validate the measured forces. Standard loads of 1000 g, 1200 g, and 1500 g were measured as 1020 ± 2 g, 1196 ± 2 g, and 1512 ± 1 g respectively. To assess the agreement between measurements Bland-Altman plot analysis was carried out. The Bland-Altman plots showed that the force platform is appropriate for both measuring static loads and dynamic loads. The collected data via this custom-made, affordable force sensor was successfully fed into the biomechanical modeling software to calculate the joint reaction forces.Conference Object A Fiber-Oriented Muscle Model for Predicting the Soft Tissue Deformation During Muscle Contraction(Mary Ann Liebert, 2022) Tang, Lei; Shan, Cunqing; Wang, Ling; Li, Dichen; Mihçin, ŞenayEffective designing of rehabilitation apparatus with high comfort and functionality depends upon the accurate characterization of the shape of the residual limb as well as its volume and shape fluctuations. The active behavior of skeletal muscles, which plays an important role in the interfacial biomechanics of human-machine interaction, is not considered in the current design processes of the rehabilitation apparatus. In this study, a three-dimensional finite element (FE) model of the human thigh was proposed to simulate the soft tissue deformation caused by muscle contraction.Article Citation - WoS: 13Citation - Scopus: 18Finite Element Study of Peek Materials Applied in Post-Retained Restorations(MDPI, 2022) Yu, Hao; Feng, Zhihong; Wang, Ling; Mihçin, Şenay; Kang, Jianfeng; Bai, Shizhu; Zhao, YiminBackground: 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.Conference Object Üst Ekstremite Hareket Kabiliyeti Değerlendirmesi için Yeni Bir Sistem Tasarımı(IEEE, 2020) Çizmecioğulları, Serkan; Mihçin, Şenay; Akan, Aydın; Koçak, Mertcan; Tosun, AliyeÜst ekstremite fonksiyon değerlendirilmesinde kullanılan yöntemlerden birisi de Eklem Hareket Açıklığı (EHA) ölçümleridir. Günümüzde bu ölçümler klinisyenin gözlemsel değerlendirmesine ve/veya gonyometrik ölçümlere dayanmaktadır. Bu ölçümlerde tekrarlanabilirlik ve güvenilirlik açısından problemler mevcuttur. Bu çalışmada üst ektremitede EHA ölçümlerinin sayısal değerlendirilmesine bağlı olarak objektif çıkarımlar yapılmasını sağlayabilecek tek kameralı bir sistem önerilmiştir. Bireylerin omuz ve dirsek fleksiyonu hareketleri kaydedilmiştir. Eş zamanlı olarak “Altın Standart” olarak OptiTrack sistemi ile de yapılan hareketler kayıt altına alınmıştır ve analiz edilmiştir. Çalışmaya 9 erkek ve 9 kadın birey katılmıştır. Hareketlerin kaydedilmesi için Kinect kamera kullanılmıştır. Kinect kamera OptiTrack sistemi ile karşılaştırılmıştır. Omuz ve dirsek fleksiyonu açıları her iki sistem ile hesaplanmıştır. Hesaplanan açılar kullanılarak her iki sistemin uyumu istatiksel olarak incelenmiştir. Bland- Altman yöntemi kullanılarak yapılan analizlerde hem erkek hem de kadın bireylerde omuz fleksiyonu ve dirsek fleksiyonu hareketleri açısından %95 güven aralığında her iki kameranın birbiriyle uyumlu olduğu tespit edilmiştir. Bu çalışma önerilen sistemin klinik tanı için güvenirliğine dair delil teşkil etmektedir.Conference Object Citation - WoS: 1Citation - Scopus: 2Parametric Analysis for the Design of Hip Joint Replacement Simulators(IEEE, 2021) Torabnia, Shams; Mihçin, Şenay; Lazoğlu, İsmailThe simulation of wear, between the components of artificial hip joint implants, is a complicated problem that does not have a robust analytical answer yet. Many studies have been conducted to predict the wear between the femur head and the acetabular cup, as the debris generated due to the wear might produce adverse effects after the surgery. Hip joint simulators provide a means to quantify the amount of wear in preclinical settings, as an in vitro method. However, this brings some other challenges in terms of bio-fidelity. The simulators use force and range of motion data as input and provide wear information as an output. For this reason, it is important to be able to simulate the realistic conditions, by the proper transmission of force and position controlling of the components. Many studies performed on wear simulators but none of them worked on the machine parameters such as power consumption and sensitivity to external inputs in detail. In this study, we perform a sensitivity analysis of the factors affecting the forces acting on the femur head. In silico simulations were performed by changing the values of acting force, friction coefficient, and radius of femur head to understand the effects of each parameter on the frictional moment of the joint. These analyses demonstrate the importance of using correct parameters while designing simulators, which accept flexible boundary conditions. The architecture of the hip simulator was also investigated for the first time. The results are expected to pave the way for improving the bio-fidelity of the simulators in the field of biomechanics. © 2021 IEEE.Article Citation - WoS: 2Mr-Guided Focused Ultrasound Application for Moving Target Tumor Ablation in Abdominal Area: Coil Selection(SAGE Publications Inc., 2021) Mihçin, Şenay; Gagliardo, Cesare; Toia, Patrizia; Dennison, Andrew; Strehlow, Jan; Melzer, AndreasBackground Magnetic Resonance Imaging (MRI)-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive thermal ablation method utilizing high-intensity focused ultrasound (HI-FU) energy for tissue ablation under MRI with real-time thermal mapping. Ablating to a dynamic target as in the liver is very challenging, requiring approval. A novel quality-assured liver tumor ablation system has been proposed for clinics. The paper reports the evaluation of conventional and new MR-receiving coils. Purpose To evaluate the suitability of MR coils as part of the MRgFUS treatment system for liver, while simulating breathing motion in pre-clinical settings. Material and Methods The novel software communicates with the MR scanner and the transducer. To monitor the temperature via proton resonance frequency (PRF) methodology echo planar imaging (EPI) sequence was used while the algorithms of static, static and dynamic tracking were tested with sonications of 100 W for 30 s on tissue-mimicking phantoms. Different coil sets were used to assess the performance of the system for fitness for dynamic thermometry. Finally, in vivo experiments were performed over a porcine model. Results Single-loop four-channel Duoflex and Gem coils provided adequate signal-to-noise ratio and contrast with consistent thermal readings. Body array coils showed severe loss of signal in dynamic cases since the integration of tracking algorithm causes low efficiency. Conclusion Body array coils are unsuitable for MRgFUS of the liver due to signal loss. The dedicated coil set with a single loop around the FUS transducer combined with four-channel arrays might be the best option for liver treatment using dynamic MRgFUS applications.