ABSTRACT
Electromagnetic actuation results suitable for wireless driven motion, where the estimation of the force between magnetic elements is usually required. This force can lead to states where the magnetic-mechanical system remains fixed, requiring constraints to avoid the transgression of these states, and Barrier Lyapunov Functions (BLF) are useful for this purpose. This work presents an adaptive controller with BLF in a magnetic pendulum with state restrictions. It employs fixed electromagnets to induce motion on a pendulum with a permanent magnet as its bob. The force between the magnetic elements is obtained through approximation functions. A new implementation strategy for the control gains introduces the effect of state restrictions on the control action based on a control BLF. Results are analyzed in both simulations and experimental stages, which prove the advantages of employing BLF controllers in mechanical systems that require the avoidance of specific boundaries.
ABSTRACT
The present study aimed to investigate whether training status would influence the capacity of a verification phase (VER) to confirm maximal oxygen uptake (VO2max) of a previous graded exercise test (GXT) in individuals with hypertension. Twelve older adults with hypertension (8 women) were recruited. Using a within-subject design, participants performed a treadmill GXT to exhaustion followed by a multistage VER both before and after a 12-wkcombined exercise training programme. Individual VO2max, respiratory exchange ratio (RER), maximal heart rate (HRmax), and rating of perceived exertion (RPE) were measured during both GXT and VER tests. Absolute and relative VO2max values were higher in VER than in GXT at baseline, but only absolute VO2max differed between bouts post-intervention (all p < 0.05). Individual VO2max comparisons revealed that 75% of the participants (9/12) achieved a VO2max value that was ≥3% during VER both before (range: +4.9% to +21%) and after the intervention (range: +3.4% to +18.8%), whereas 91.7% (11/12) of the tests would have been validated as a maximal effort if the classic criteria were employed. A 12-wk combined training intervention could not improve the capacity of older adults with hypertension to achieve VO2max during a GXT, as assessed by VER.
Subject(s)
Hypertension , Oxygen Consumption , Aged , Exercise/physiology , Exercise Test , Exercise Therapy , Female , Heart Rate/physiology , Humans , Hypertension/therapy , Oxygen Consumption/physiologyABSTRACT
Se realiza un estudio con el objetivo de caracterizar la cirugía mayor ambulatoria en el Centro de Diagnóstico Integral Rafael Antonio Pérez Ruedas del municipio Pampán, Venezuela, en el período comprendido entre febrero y octubre de 2011. Incluye los 115 pacientes intervenidos quirúrgicamente en este período de tiempo y que dieron su consentimiento a participar en el estudio. Se estudian las variables: edad, sexo, tipo de intervención quirúrgica, método anestésico, evolución, complicaciones y estadía hospitalaria. El 73.25 por ciento de los pacientes son intervenidos quirúrgicamente de forma ambulatoria con un mínimo de complicaciones y una gran aceptación por parte de los mismos, quedando demostrado el bienestar psicosocial que representa para el paciente y sus familiares este método y las ventajas del mismo (AU)
a study is done to characterize the ambulatory surgery in the Integral Diagnostic Center Rafael Antonio Perez Pampán, Venezuela, from February to October 2011. Includes the 115 patients operated on during this period of time and who consented to participate in the study. Variables were studied: age, sex, type of surgery, anesthetic method, evolution, complications and hospital stay. The 73.25por ciento of the patients are operated on an ambulatory way with minimal complications and a large acceptance therefore, psychosocial well-being to the patient and family were demonstrated in the research besides methods and the advantages (AU)