A Workstation for microassembly

In this paper, an open-architecture, reconfigurable microassembly workstation for efficient and reliable assembly of micromachined parts is presented. The workstation is designed to be used as a research tool for investigation of the problems in microassembly. The development of such a workstation includes the design of: (i) a manipulation system consisting of motion stages providing necessary travel range and precision for the realization of assembly tasks, (ii) a vision system to visualize the microworld and the determination of the position and orientation of micro components to be assembled, (iii) a robust control system and necessary mounts for the end effectors in such a way that according to the task to be realized, the manipulation tools can be easily changed and the system will be ready for the predefined task. In addition tele-operated and semi-automated assembly concepts are implemented. The design is verified by implementing the range of the tasks in micro-parts manipulation. The versatility of the workstation is demonstrated and high accuracy of positioning is sho

In-wheel motor design for electric vehicles

In this work an in-wheel electric motor prototype has been designed for experimental purposes. In-Wheel Motor (Hub motor) can be used in electric cars with 4 wheel independent drive configuration. Within every wheel, there can be one “Direct-Drive In-Wheel Motor” to generate the necessary torque per wheel. Unlike conventional “central drive unit” systems, torque as well as the power and speed can be supplied to each tire independently. The difference in this work is the design of a direct drive electric motor which is able to carry transverse loading acts on a tire. Type of the motor is called inverted configuration or outer rotor structure in the literature. The electric machine designed in this work is Switched Reluctance Machine. First a 3D solid model was created. Necessary strength analyses have been done. Simultaneously, electromagnetic FEA has been done, when it is necessary either of the designs were modified until it converged to a set of consistent dimensions for both mechanic and electromagnetic design. Last, the results of the electromagnetic analysis were embedded into a hybrid simulation model, in order to check the coherency between the design and the analysis. The results were coherent

In-wheel motor design for electric vehicles

In this thesis an in-wheel electric motor prototype has been designed for experimental purposes. In-Wheel Motor (Hub motor) can be used in electric cars with 4 wheel independent drive configuration. Within every wheel, there can be one "Direct- Drive In-Wheel Motor" to generate the necessary torque per wheel. Unlike conventional "central drive unit" systems, torque as well as the power and speed can be supplied to each tyre independently. The difference in this work is the design of a direct drive electric motor which is able to carry transverse loading acts on the tyre. Type of the motor is called inverted configuration or outer rotor structure in the literature, in which the rotating element is the casing of the motor. The electric machine designed in the thesis is Switched Reluctance Machine. First a 3D solid model was created. Necessary strength analyses have been done. Simultaneously, electromagnetic FEA have been done, when it is necessary either of the designs were modified until it converged to a set of consistent dimensions for both mechanic and electromagnetic design. Last, the results of the electromagnetic analysis were embedded into a hybrid simulation model, in order to check the coherency between the design and the analysis. The results were coherent

A versatile and reconfigurable microassembly workstation

In this paper, a versatile and reconfigurable microassembly workstation designed and realized as a research tool for investigation of the problems in microassembly and micromanipulation processes and recent developments on mechanical and control structure of the system with respect to the previous workstation are presented. These developments include: (i) addition of a manipulator system to realize more complicated assembly and manipulation tasks, (ii) addition of extra DOF for the vision system and sample holder stages in order to make the system more versatile (iii) a new optical microscope as the vision system in order to visualize the microworld and determine the position and orientation of micro components to be assembled or manipulated, (iv) a modular control system hardware which allows handling more DOF. In addition several experiments using the workstation are presented in different modes of operation like tele-operated, semiautomated and fully automated by means of visual based schemes

Mikro montaj İş İstasyonu

Bu makalede, mikro boyuttaki komponentlerin verimli ve güvenilir montajı için açık-mimarili, tekrar yapılandırılabilir bir mikromontaj iş istasyonu sunulmaktadır. Bu iş istasyonu mikro dünyadaki problemlerin çözümlendirilmesine yardımcı olmak amacıyla bir araştırma aracı olarak tasarlanmıştır. Böyle bir iş istasyonunun geliştirilmesi aşağıdaki alt sistemlerin tasarımını içermektedir: (i) montaj görevlerininin gerçekleştirilebilmesi için yeterli hareket menzilini ve hassasiyeti sağlayabilecek hareket platformlarından oluşan bir manipülatör sistemi, (ii) mikro dünyanın görselleştirilmesini ve montajı yapılacak olan mikro parçaların konum ve yönelimlerini belirleyebilmek için bir görü sistemi, (iii) dayanıklı bir denetleme sistemi ve bunlara ek olarak manipülasyon araçlarının kolayca değişmesine olanak sağlayan ve sistemin önceden belirlenmiş göreve hazır hale getirilmesine yardımcı olacak uç takımlar için gerekli fikstürler. Ayrıca sistemde kumandalı ve yarı otomatik montaj uygulamaları da gerçekleştirilmiştir. Tasarım mikro parça manipülasyonu içeren çeşitli uygulamalar yapılarak test edilmiştir. İş istasyonunun çok yönlülüğü ve yüksek doğrulukta konumlama yeteneği yapılan deneylerle gösterilmiştir

Çok Yönlü ve Tekrar Yapılandırılabilir Mikro Montaj İş İstasyonu

Bu makalede, mikro montaj ve mikro manipülasyon süreçlerindeki sorunların incelenmesi amacıyla bir araştırma aracı olarak tasarlanan ve geliştirilen çok yönlü ve tekrar yapılandırılabilir mikro montaj iş istasyonu ve yine aynı grup tarafından geliştirilen bir önceki sistem üzerinde mekanik ve denetim yapıları açısından yapılan geliştirmeler sunulmaktadır. Bu geliştirmeler; (i) daha karmaşık montaj ve manipülasyon işlemlerinin gerçekleştirilebilmesi için ek bir manipülatör modülünün eklenmesi, (ii) sistemi daha yetenekli kılabilmek için görü sistemi ve numune taşıyıcı platformlarına ek hareket serbestlik derecesi eklenmesi (iii) mikro dünyanın görüntülenmesi ve montajı yapılacak veya manipüle edilecek parçaların konum ve yönelimlerinin belirlenebilmesi amacıyla görü sistemi olarak yeni bir optik mikroskobun eklenmesi (iv) daha fazla serbestlik derecesinin denetimini sağlayabilmek amacıyla varolan sistemin daha modüler bir denetim sistemi donanımı ile değiştirilmesi gibi unsurları içermektedir. Ayrıca sistemde kumandalı, yarı otomatik ve görü bazlı yöntemler aracılığı ile tamamen otomatik çalışma modlarında yapılan deney sonuçları da sunulmaktadır

Contribution of Endorectal Ultrasound, Magnetic Resonance Imaging and Positron Emission Tomography to Operation Strategy in Rectal Cancer

Objective:Colorectal cancer is the most common type of cancer in the gastrointestinal tract. Preoperative staging is important for applying appropriate treatment modalities. The role of endorectal ultrasonography (ERUS), magnetic resonance imaging (MRI) and positron emission-computed tomography (PET-CT) in rectal cancer patients was evaluated.Method:In this study, between October 2010-April 2012, 30 patients who were diagnosed as rectal cancer clinically and histopathologically were evaluated with ERUS, MRI and PET-CT preoperatively and results were compared with histopathologic findings.Results:Between October 2010-April 2012, 30 patients who were diagnosed as rectal cancer with biopsy in Bezmialem University Medical Faculty Hospital General Surgery Department were included in this study [20 male (66.6%), 10 female (33.3%) and their ages are 38-75 years old, 21 of them received neoadjuvant treatment and 9 of them did not received]. All patients were evaluated with MRI, ERUS and PETCT preoperatively. Rectal cancer patients who are primarily operated from rectal adenocarcinoma were included in this study. For T staging, preoperative MRI, ERUS and PET-CT staged 9 (31%), 12 (41%) and 12 (40%) of 30 patients accurately, respectively. For N staging, preoperative MRI, ERUS and PET-CT staged 15 (51%), 16 (55.1%) and 17 (56.6%) of 30 patients accurately, respectively. In comparison to other modalities, PET-CT did not yield a significant difference in staging and did not change operation strategy. PET-CT detected distant metastasis in 3 patients. One of them was liver and two of them were lung metastasis. Biopsies from mass predicted as lung metastasis did not result as metastasis. PET-CT has high rates of false positivity to detect distant metastasis. In statistical analysis, significant p-values for evaluation could not be obtained.Conclusion:Efficacy of routine use of PET-CT on staging, evaluation of T, N and extramesorectal spread could not be shown

Effects of obesity on retrobulbar flow hemodynamics: color Doppler ultrasound evaluation

<div><p>ABSTRACT Purpose: To evaluate intraocular pressure (IOP) and extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of obesity on retrobulbar blood flow. Methods: Fifty-nine patients were included in this prospective study. Patients were divided into two groups according to body mass index: Group 1 (31 obese patients) and Group 2 (28 non-obese patients). IOP was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels. Results: The mean IOP was 18 ± 6.68 mmHg in the obese group and 13.71 ± 1.60 mmHg in the control group (p<0.001). When the CDU values for the central retinal artery were compared between the groups, the pulsatility index was found to be significantly lower in the obese group than in the control group (p<0.001). When the CDU values for the ophthalmic artery (OA) were compared between the groups, the peak systolic velocity (p<0.001) and end-diastolic velocity (p=0.002) values were found to be significantly lower in the obese group than in the control group. Conclusions: Obese patients have a higher mean IOP and lower flow velocity than non-obese patients. Increased IOP together with decreased retrobulbar blood flow, particularly in obese individuals, may increase the risk of glaucoma development.</p></div