Diseño mecánico estructural de un exoesqueleto orientado a la rehabilitación para extremidades inferiores de pacientes masculinos de edad productiva en la ciudad de Riobamba.

El principal objetivo de esta propuesta tecnológica es el diseño mecánico estructural de un exoesqueleto orientado a la rehabilitación para extremidades inferiores de pacientes masculinos de edad productiva en la ciudad de Riobamba, tomando en cuenta las características antropométricas de la población. El exoesqueleto se diseñó para dos rutinas, una en base al ciclo de marcha humana y la otra, para movimiento de rehabilitación de rodilla. En la elaboración de la propuesta tecnológica, se estudió el estado del arte de este tipo de dispositivos mecatrónicos, se investigó y analizó la antropometría de las extremidades inferiores y el ciclo de la marcha humana, y se realizó un análisis de alternativas, considerando la voz del usuario y del ingeniero, luego se llevó a cabo la caracterización antropométrica, posteriormente, se efectuó la modelación CAD del exoesqueleto en SolidWorks, se procedió a realizar el análisis dinámico de la estructura en MSC ADAMS, definiendo el entorno de simulación para las dos rutinas, para obtener las fuerza y torques reaccionantes en cada articulación, procediendo a la validación de resistencia del exoesqueleto en ANSYS. En el proceso de análisis del modelo propuesto, se dividió la estructura en cuatro subensamblajes: cadera, muslo, canilla y pie, al verificar el comportamiento de éstos bajo la acción de las fuerzas determinadas con ADAMS, se obtuvo un factor de seguridad mínimo de 2.8, el cual se presenta en la canilla del exoesqueleto. Se recomienda la estructura diseñada como base para futuros proyectos de la Facultad de Mecánica de la Escuela Superior Politécnica de Chimborazo, así como su metodología es un aporte para futuras investigaciones en el campo de la biomecánica, ésta cumple con los parámetros requeridos para realizar la rehabilitación física de las extremidades inferiores para personas masculinas en edad productiva de máximo 85 kg de peso.The main objective of this technological proposal is the structural mechanical design of an exoskeleton oriented to the rehabilitation of lower limbs of male patients of productive age in the city of Riobamba, taking into account the anthropometric characteristics of the population. The exoskeleton was designed for two routines, one based on the human gait cycle and the other for knee rehabilitation movement. In the development of the technological proposal, the state of the art of mechatronics devices was studied, the anthropometry of the lower limbs and the cycle of the human gait were investigated and analyzed, and an analysis of alternatives was performed considering the voice of the user and of the engineer, then the anthropometric characterization was carried out, then the CAD model of the exoskeleton was carried out in SolidWorks, the dynamic analysis of the structure in MSC ADAMS was carried out, defining the simulation environment for the two routines, to obtain the force and reacting torques in each joint, proceeding to the validation of resistance of the exoskeleton in ANSYS. In the process of analysis of the proposed model, the structure was divided into four subassemblies: hip, thigh, shin and foot, when verifying their behavior under the action of forces determined with ADAMS, a minimum safety factor of 2.8, Which is presented in the quill of the exoskeleton. It is recommended the structure designed as a basis for future projects of the Faculty of Mechanics of the Polytechnic School of Chimborazo, as well as its methodology is a contribution for future research in the field of biomechanics, it meets the parameters required to carry out the physique rehabilitation of the lower extremities for men of productive age of maximum 85 kg

Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Disease∗

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease