Implementation and Comparison of Controllers for Planar Robots

John Kern,Claudio Urrea,Hugo Torres 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

The nonlinear behavior and the high performance requirement are the main problems that appear in the design of manipulator robots and their controllers. For that reason, the simulation, realtime execution and comparison of the performance of controllers applied to a robot with three degrees of freedom are presented. Five controllers are prepared to test the robot"s dynamic model: predictive; hyperbolic sine-cosine; sliding mode; hybrid composed of a predictive + hyperbolic sine-cosine controller; and adaptive controller. A redundant robot, a communication and signal conditioning interface, and a simulator are developed by means of the MatLab/Simulink software, which allows analyzing the dynamic performance of the robot and of the designed controllers. The manipulator robot is made to follow a test trajectory which, thanks to the proposed controllers, it can do. The results of the performance of this manipulator and of its controllers, for each of the three joints, are compared by means of RMS indices, considering joint errors according to the imposed trajectory and to the controller used.

Implementation and Comparison of Controllers for Planar Robots

Kern, John,Urrea, Claudio,Torres, Hugo The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

The nonlinear behavior and the high performance requirement are the main problems that appear in the design of manipulator robots and their controllers. For that reason, the simulation, real-time execution and comparison of the performance of controllers applied to a robot with three degrees of freedom are presented. Five controllers are prepared to test the robot's dynamic model: predictive; hyperbolic sine-cosine; sliding mode; hybrid composed of a predictive + hyperbolic sine-cosine controller; and adaptive controller. A redundant robot, a communication and signal conditioning interface, and a simulator are developed by means of the MatLab/Simulink software, which allows analyzing the dynamic performance of the robot and of the designed controllers. The manipulator robot is made to follow a test trajectory which, thanks to the proposed controllers, it can do. The results of the performance of this manipulator and of its controllers, for each of the three joints, are compared by means of RMS indices, considering joint errors according to the imposed trajectory and to the controller used.

Sequential Hybrid Repair of Aorta and Bilateral Common Iliac Arteries Secondary to Chronic Aortic Dissection with Extensive Aneurysmal Degeneration in a Marfan Patient

Carlos A. Hinojosa,Javier E. Anaya-Ayala,Hugo Laparra-Escareno,Rene Lizola,Adriana Torres-Machorro 대한혈관외과학회 2017 Vascular Specialist International Vol.33 No.3

Marfan syndrome is a connective tissue disorder associated with aortic dissection, aneurysmal degeneration and rupture. These cardiovascular complications represent the main cause of mortality, therefore repair is indicated. We present a 35-year-old woman who experienced acute onset of chest pain. Her imaging revealed a chronic DeBakey type I dissection with aortic root dilation and descending thoracic aneurysmal degeneration. She underwent a Bentall procedure and endovascular exclusion of the descending thoracic aortic aneurysm. She was closely followed and 2 years later a computed tomography angiography (CTA) revealed the aneurysmal degeneration of the thoracoabominal aorta and bilateral iliac arteries. The patient underwent a composite reconstruction using multivisceral branched and bifurcated Dacron grafts. At 5 years from her last surgery, a CTA revealed no new dissection or further aneurysmal degenerations. Aortic disease in Marfan patients is a complex clinical problem that may lead to secondary or tertiary aortic reconstructions; close follow-up is mandatory.

Aortobifemoral Reconstruction with Right Extra-Anatomic Obturator Foramen Bypass due to a Septic Groin

Carlos A. Hinojosa,Javier E. Anaya-Ayala,Hugo Laparra-Escareno,Rene Lizola,Adriana Torres-Machorro 대한혈관외과학회 2016 Vascular Specialist International Vol.32 No.2

The aortic bifurcation and iliac vessels are common sites of atherosclerotic occlusive disease causing the clinical expression known as “Leriche’s syndrome”. An aortobifemoral bypass grafting in the setting of a septic groin remains a significant challenge to vascular surgeons. We present a 65-year-old male with complete occlusion of the distal aorta and iliac arteries; he had undergone a leftaxillo-femoral and femoral-femoral artery bypass 2 years prior to our evaluation. Owing to a complex graft infection in the right groin and worsening lower extremity ischemia, we performed an aortobifemoral reconstruction through the right obturator membrane. This report highlights the safety and efficacy of the obturator bypass for avoiding infected groins while preserving vascular continuity and durability with 78 months of secondary patency rate.

Effect of sterilization on 3-point dynamic response to in vitro bending of an Mg implant

Luis Humberto Campos Becerra,Marco Antonio Loudovic Hernández Rodríguez,Raúl Lesso Arroyo,Hugo Esquivel Solís,Alejandro Torres Castro 한국생체재료학회 2021 생체재료학회지 Vol.25 No.2

Background: The aim of the study is to characterize a biomedical magnesium alloy and highlighting the loss of mechanical integrity due to the sterilization method. Ideally, when using these alloys is to delay the onset of degradation so that the implant can support body loads and avoid toxicological effects due to the release of metal ions into the body. Methods: Standardized procedures according to ASTM F-1264 and ISO-10993-5 were used, respecting detailed methodological controls to ensure accuracy and reproducibility of the results, this testing methodology is carried out in accordance with the monographs of the Pharmacopoeia for the approval of medical devices and obtaining a health registration. An intramedullary implant (IIM) manufactured in magnesium (Mg) WE43 can support loads of the body in the initial period of bone consolidation without compromising the integrity of the fractured area. A system with these characteristics would improve morbidity and health costs by avoiding secondary surgical interventions. Results: As a property, the fatigue resistance of Mg in aggressive environments such as the body environment undergoes progressive degradation, however, the autoclave sterilization method drastically affects fatigue resistance, as demonstrated in tests carried out under in vitro conditions. Coupled with this phenomenon, the relatively poor biocompatibility of Mg WE43 alloys has limited applications where they can be used due to low acceptance rates from agencies such as the FDA. However, Mg alloy with elements such as yttrium and rare earth elements (REEs) have been shown to delay biodegradation depending on the method of sterilization and the physiological solution used. With different sterilization techniques, it may be possible to keep toxicological effects to a minimum while still ensuring a balance between the integrity of fractured bone and implant degradation time. Therefore, the evaluation of fatigue resistance of WE43 specimens sterilized and tested in immersion conditions (enriched Hank’s solution) and according to ASTM F-1264, along with the morphological, crystallinity, and biocompatibility characterization of the WE43 alloy allows for a comprehensive evaluation of the mechanical and biological properties of WE43. Conclusions: These results will support decision-making to generate a change in the current perspective of biomaterials utilized in medical devices (MDs), to be considered by manufacturers and health regulatory agencies. An implant manufactured in WE43 alloy can be used as an intramedullary implant, considering keeping elements such as yttrium-REEs below as specified in its designation and with the help of a coating that allows increasing the life of the implant in vivo.

Feasibility and efficacy of the Vojta therapy in subacromial impingement syndrome : a randomized controlled trial

María Lidia Juárez-Albuixech,Olga Redondo-González,Inmaculada Tello-Díaz-Maroto,Jorge Lucas Torres de la Guía,Jorge Hugo Villafañe,Carmen Jiménez-Antona 한국운동재활학회 2021 JER Vol.17 No.4