Development of a Test-Bench for the Accurate Positioning of Scintillation Detector Modules for Medical Imaging Applications

When assessing the impact of novel concepts of scintillation block detectors for PET tomography by measuring the performance of single modules, or one module in coincidence with another, it is not trivial to translate the results of these investigations into a real PET scanner, made of several rings of modules. In particular, the real sensitivity, the signal to noise ratio of reconstructed images, and the spatial resolution (especially in the areas far from the center of field of view) among others are very critical to understand how good a PET scanner will perform for a real patient, and they are specific of the fully assembled scanner. Hence, demonstrating that a new idea under development is worth implementing in a real scanner requires more than just a measurement with two modules one in front of the other. For this reason, the set-up described in the present work will permit to reproduce full ring conditions using only a few modules at the price of a very good positioning accuracy.I must express all my gratitude towards one of my colleagues at CERN MME Group, Tommi Mikkola, for his infinite patience and teachings when reviewing the design and drawings of the mechanical parts

Design of an active reconfigurable 2R joint

Ponencia presentada en 15th IFToMM World Congress on Mechanism and Machine ScienceThe increasing flexibility requirements in the manufacturing processes has led to the development of novel reconfigurable mechanisms to be implemented in ma-chine heads and tables. This is the case of the reconfigurable parallel manipulators which are also used in a wide variety of applications. These mechanisms include often in their kinematic chains active or reconfigurable joints. In this paper, a 2R active reconfigurable joint is presented. As well as carrying out the kinematic characterization of the joint, a demonstrative prototype has been also built.The authors wish to acknowledge the financial support received from the Spanish Government through the Ministerio de Economía y Competitividad (Project DPI2015-67626-P (MINECO/FEDER, UE)) and the financial support given to the research group through the pro-ject with Ref. IT949-16, given by the Departamento de Educación, Política Lingüística y Cultura of the Regional Government of the Basque Country

Development of a Test-Bench for the Accurate Positioning of Scintillation Detector Modules for Medical Imaging Applications

When assessing the impact of novel concepts of scintillation block detectors for PET tomography by measuring the performance of single modules, or one module in coincidence with another, it is not trivial to translate the results of these investigations into a real PET scanner, made of several rings of modules. In particular, the real sensitivity, the signal to noise ratio of reconstructed images, and the spatial resolution (especially in the areas far from the center of field of view) among others are very critical to understand how good a PET scanner will perform for a real patient, and they are specific of the fully assembled scanner. Hence, demonstrating that a new idea under development is worth implementing in a real scanner requires more than just a measurement with two modules one in front of the other. For this reason, the set-up described in the present work will permit to reproduce full ring conditions using only a few modules at the price of a very good positioning accuracy.I must express all my gratitude towards one of my colleagues at CERN MME Group, Tommi Mikkola, for his infinite patience and teachings when reviewing the design and drawings of the mechanical parts

Design and Testing of Two Haptic Devices Based on Reconfigurable 2R Joints

per presents the design and testing of two haptic devices, based on reconfigurable 2R joints: an active 2R spherical mechanism-based joint and a differential gear-based joint. Based on our previous works, in which the design and kinematic analysis of both reconfigurable joints were developed, the experimental setup and the various tasks intended to test the reconfigurability, precision, force feedback system and general performance, are presented herein. Two control modes for the haptic device operation are proposed and studied. The statistical analysis tools and their selection principles are described. The mechanical design of two experimental setups and the main elements are considered in detail. The Robot Operating System nodes and the topics that are used in the software component of the experimental setup are presented and explained. The experimental testing was carried out with a number of participants and the corresponding results were analyzed with the selected statistical tools. A detailed interpretation and discussion on of the results is provided.The authors wish to acknowledge the financial support received from the Spanish Government through the Ministerio de Ciencia e Innovación (Project PID2020-116176GB-I00) financed by MCIN/AEI/10.13039/501100011033, and the support for the research group through Project IT949-16 provided by the Departamento de Educación, Política Lingüística y Cultura from the regional Basque Government

Improving Skills in Mechanism and Machine Science Using GIM Software

The field of education has evolved significantly in recent years as it has incorporated new pedagogical methodologies. Many of these methodologies are designed to encourage students’ participation in the learning process. The traditional role of the student as a passive receiver of content is no longer considered valid. Teaching in mechanical engineering is no stranger to these changes either, where new learning activities have been designed to complement theory-heavy lectures. These activities take place in both physical and virtual laboratories. In case of the latter, the use of the GIM software (developed at the Department of Mechanical Engineering of the University of the Basque Country UPV/EHU, Spain) is a promising option. In this paper, features of the GIM that are most frequently used to support and exemplify the theoretical concepts taught in lectures are described using a case study. In addition, GIM is integrated into different learning activities to show its potential as a tool for learning and self-evaluation.This research was funded by Ministerio de Economía y Competitividad, Spanish Government Project, MINECO/FEDER, UE (grant number DPI2015-67626-P), Departamento de Educación, Política Lingüística y Cultura, Regional Government of the Basque Country (grant number IT949-16) and University of the Basque Country UPV/EHU (grant number PIE2012/14)

Parallel manipulators: practical applications and kinematic design criteria. Towards the modular reconfigurable robots

Post-PrintModern robotic manipulators play an essential role in industry, developing several tasks in an easy way, enhancing the accuracy of the final product and reducing the executing time. Also they can be found in other fields as aerospace industry, several medical applications, gaming industry, and so on. In particular, the parallel manipulators have acquired a great relevance in the last years. Indeed, many research activities and projects deal with the study and develop-ment of this type of robots. Nevertheless, usually, a bilateral communication between industry and research does not exist, even among the different existing research areas. This causes a lack of knowledge regarding works that have been carried out, the ones that are under devel-opment and the possible future investigations. Hence, once a specific field of knowledge has acquired a certain level of maturity, it is convenient to reflect its current state of the art. In this sense, the authors of this paper present a review of the different fields in which parallel ma-nipulators have a significant participation, and also the most active research topics in the anal-ysis and design of these robots. Besides, several contributions of the authors to this field are cited.The authors wish to acknowledge the financial support received from the Spanish Government through the "Ministerio de Economía y Competitividad" (Project DPI2015-67626-P (MINECO/FEDER, UE)), the financial support from the Uni-versity of the Basque Country (UPV/EHU) under the program UFI 11/29 and the support to the research group, through the project with ref. IT949-16, given by the "Departamento de Educación, Política Lingüística y Cultura" of the Regional Government of the Basque Country

Insights into mechanism kinematics for protein motion simulation

Background: The high demanding computational requirements necessary to carry out protein motion simulations make it difficult to obtain information related to protein motion. On the one hand, molecular dynamics simulation requires huge computational resources to achieve satisfactory motion simulations. On the other hand, less accurate procedures such as interpolation methods, do not generate realistic morphs from the kinematic point of view. Analyzing a protein's movement is very similar to serial robots; thus, it is possible to treat the protein chain as a serial mechanism composed of rotational degrees of freedom. Recently, based on this hypothesis, new methodologies have arisen, based on mechanism and robot kinematics, to simulate protein motion. Probabilistic roadmap method, which discretizes the protein configurational space against a scoring function, or the kinetostatic compliance method that minimizes the torques that appear in bonds, aim to simulate protein motion with a reduced computational cost. Results: In this paper a new viewpoint for protein motion simulation, based on mechanism kinematics is presented. The paper describes a set of methodologies, combining different techniques such as structure normalization normalization processes, simulation algorithms and secondary structure detection procedures. The combination of all these procedures allows to obtain kinematic morphs of proteins achieving a very good computational cost-error rate, while maintaining the biological meaning of the obtained structures and the kinematic viability of the obtained motion. Conclusions: The procedure presented in this paper, implements different modules to perform the simulation of the conformational change suffered by a protein when exerting its function. The combination of a main simulation procedure assisted by a secondary structure process, and a side chain orientation strategy, allows to obtain a fast and reliable simulations of protein motion.The authors wish to acknowledge the financial support received from the Spanish Government through the Ministerio de Economia y Competitividad (Project DPI2011-22955), the Regional Government of the Basque Country through the Departamento de Educacion, Universidades e Investigacion (Project IT445-10) and UPV/EHU under program UFI 11/29 and by Grants from the Department of Education, Universities and Research of the Basque Government (PI2010-17), from the Department of Industry of the Basque Government (ETORTEK Program IE05-147 and IE07-202), from the Bizkaia Country (Exp. 7/13/08/2006/11 and 7/13/08/2005/14), and from the Spanish Ministry of Economy and Innovation (BFU2010-17857 and SICI-CONSOLIDER Program CSD2008-00005) (all to L.A.M.-C.)

Translational parallel manipulator with Pa2 kinematic joints

The kinematic pair Pa2 is composed of two interlinked parallelograms. It has two degrees of freedom that generate a translational plane variable with position. It has a structure different from the PaPa pair, which is composed also by two parallelograms but generates a constant translational plane. Currently, the Pa2 pair is used at conceptual level but it is not used in al-most any practical application. There are advantages and drawbacks in using it. The main drawback is the high number of redundant constraints that this pair possesses. However, sub-stituting carefully the revolute joints by spherical joints can eliminate these redundant con-straints. Also, this pair constitutes a more rigid structure that replaces adequately the problem-atic passive prismatic joints. In this paper, will be presented a preliminary study of a translational parallel manipulator (PM) based on the use of the Pa2 pair: the 3-PPa2 that contains redundant constraints in its global structure. To study the potentiality of the PM presented in this paper, the following analyses will be done: position and velocity (direct and inverse kinematics), workspace and singularity analysis. Also the potentiality to be optimised will be studied.This work was supoorted by the Spanish Government through the Ministerio de Economía y Competitividad (Project DPI2015-67626-P (MINECO/FEDER, UE)), the financial support from the University of the Basque Country (UPV/EHU) under the program UFI 11/29 and the support to the research group, through the project with ref. IT949-16, given by the Departamento de Educación, Política Lingüística y Cultura of the Regional Government of the Basque Country

Multioperation capacity of parallel manipulators basing on generic kinematic chain approach

The idea of designing multioperation mechanisms capable of performing different tasks has gained prominence in the last years. These mechanisms, commonly called reconfig- urable mechanisms, have the ability to change their configuration. At present, this type of mechanisms is capturing the attention of design engineers because of their great po- tential in many industrial applications. In this paper, the basis for the development of a methodology intended for the analysis and design of multioperational parallel manipu- lators is presented. First, the structural synthesis of 6 degree-of-freedom (dof) kinematic chains that can form a 6 dof manipulator is established. Next, a general purpose approach for non-redundant parallel manipulators (PM) will be presented. This procedure enables obtaining the Jacobian matrices of any 6 dof or low-mobility PM whose kinematic chains belong to the library of chains derived from the structural synthesis. To demonstrate the versatility of the procedure, it will be applied to three PM: the first one, a 6 dof PM, the second one, a reconfigurable 6 dof PM, and finally, a low-mobility PM.This work was supoorted by the Spanish Government through the Ministerio de Economía y Competitividad (Project DPI2015-67626-P (MINECO/FEDER, UE)), the financial support from the University of the Basque Country (UPV/EHU) un- der the program UFI 11/29 and the support to the research group, through the project with ref. IT949-16 , given by the Departamento de Educación , Política Lingüística y Cultura of the Regional Government of the Basque Country