Linear parameter-varying model to design control laws for an artificial pancreas

The contribution of this work is the generation of a control-oriented model for insulin-glucose dynamic regulation in type 1 diabetes mellitus (T1DM). The novelty of this model is that it includes the time-varying nature, and the inter-patient variability of the glucose-control problem. In addition, the model is well suited for well-known and standard controller synthesis procedures. The outcome is an average linear parameter-varying (LPV) model that captures the dynamics from the insulin delivery input to the glucose concentration output constructed based on the UVA/Padova metabolic simulator. Finally, a system-oriented reinterpretation of the classical ad-hoc 1800 rule is applied to adapt the model's gain. The effectiveness of this approach is quantified both in open- and closed-loop. The first one by computing the root mean square error (RMSE) between the glucose deviation predicted by the proposed model and the UVA/Padova one. The second measure is determined by using the ν-gap as a metric to determine distance, in terms of closed-loop performance, between both models. For comparison purposes, both open- (RMSE) and closed-loop (ν-gap metric) quality indicators are also computed for other control-oriented models previously presented. This model allows the design of LPV controllers in a straightforward way, considering its affine dependence on the time-varying parameter, which can be computed in real-time. Illustrative simulations are included. In addition, the presented modeling strategy was employed in the design of an artificial pancreas (AP) control law that successfully withstood rigorous testing using the UVA/Padova simulator, and that was subsequently deployed in a clinical trial campaign where five adults remained in closed-loop for 36 h. This was the first ever fully closed-loop clinical AP trial in Argentina, and the modeling strategy presented here is considered instrumental in resulting in a very successful clinical outcome.Fil: Colmegna, Patricio Hernán. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sánchez Peña, Ricardo S.. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gondhalekar, R.. Harvard University; Estados Unido

Interpolation for gain-scheduled control with guarantees

Here, a methodology is presented which considers the interpolation of linear time-invariant (LTI) controllers designed for different operating points of a nonlinear system in order to produce a gain-scheduled controller. Guarantees of closed-loop quadratic stability and performance at intermediate interpolation points are presented in terms of a set of linear matrix inequalities (LMIs). The proposed interpolation scheme can be applied in cases where the system must remain at the operating points most of the time and the transitions from one point to another rarely occur, e.g., chemical processes, satellites.Fil: Bianchi, Fernando Daniel. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sánchez Peña, Ricardo S.. Instituto Tecnológico de Buenos Aires; Argentin

Phenomenological based model of hydrogen production using an alkaline self-pressurized electrolyzer

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The aim of this work is to develop the phenomenological based modeling of a self-pressurized alkaline electrolyser with the objective of predicting the cross-contamination of the gases produced. A proposed model, built in Matlab®, represents the dynamical evolution in real electrolysers, and anticipates operational variables: level, pressure and all concentrations. Dynamic responses in the concentrations of the electrolytic cell, and variations in both level and pressure at the chamber due to the change in current and diffusivity, are reported. The equations by which the variables can be computed are also presented. The proposed model is ready for the corresponding adjustment of parameters based on experimental measurements taken from an available prototype and through a suitable identification process.Peer ReviewedPostprint (author's final draft

Distributed formation control of multiple unmanned aerial vehicles over time-varying graphs using population games

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper presents a control technique based on distributed population dynamics under time-varying communication graphs for a multi-agent system structured in a leader-follower fashion. Here, the leader agent follows a particular trajectory and the follower agents should track it in a certain organized formation manner. The tracking of the leader can be performed in the position coordinates x; y; and z, and in the yaw angle phi. Additional features are performed with this method: each agent has only partial knowledge of the position of other agents and not necessarily all agents should communicate to the leader. Moreover, it is possible to integrate a new agent into the formation (or for an agent to leave the formation task) in a dynamical manner. In addition, the formation configuration can be changed along the time, and the distributed population-games-based controller achieves the new organization goal accommodating conveniently the information-sharing graph in function of the communication range capabilities of each UAV. Finally, several simulations are presented to illustrate different scenarios, e.g., formation with time-varying communication network, and time-varying formationPeer ReviewedPostprint (author's final draft

Eliminación de la malaria en el Perú

Editorial (Sin resumen

A gain-scheduled LPV control for oxygen stoichiometry regulation in PEM fuel cell systems

The article addresses the LPV control of a Polymer Electrolyte Membrane Fuel Cell (PEMFC). In order to optimize efficiency, PEMFCs require reliable control systems ensuring stability and performance, as well as robustness to model uncertainties and external perturbations. On the other hand, PEMFCs present a highly nonlinear behavior that demands nonlinear and/or adaptive control strategies to achieve high performance in the entire operating range. Here, a linear parameter varying (LPV) gain scheduled control is proposed. The control is based on a piecewise affine LPV representation of the PEMFC, a model that can be available in practice. In order to deal with the saturation of the control action, an LPV anti-windup compensation is also proposed. The complete control strategy is applied to several experimental practical situations in a laboratory fuel cell system to evaluate its performance and the reliability of the proposed algorithms.The research of F.D. Bianchi was supported by the European Regional Development Funds (ERDF, FEDER Programa Competitivitat de Catalunya 2007-2013). The research of C. Kunusch has been supported by the Seventh Framework Programme of the European Community through the Marie Curie actions (GA: PCIG09-GA-2011-293876) and project Puma-Mind (GA: FCH-JU-2011-1-303419), as well as by the CICYT project DPI2011-25649 (MICINN-Spain). The research of C. Ocampo-Martinez has been supported by the project MACPERCON (Ref. 201250E027) of the CSIC. The research of R.S. Sánchez Peña has been supported by CONICET and grant PICT2008-290 from the PRH Program of the Ministry of Science, Technology and Innovation of Argentina.Peer Reviewe

Retinopatía de la prematuridad y su evolución en niños sobrevivientes de bajo peso al nacer egresados del Servicio de Neonatología del Hospital Regional Docente de las Mercedes de Chiclayo durante 2012-2013

Objetivo: Describir la evolución de retinopatía de la prematuridad (ROP) en recién nacidos con bajo peso al nacer egresados del Servicio de Neonatología del Hospital Regional Docente de las Mercedes durante los años 2012-2013. Materiales y Métodos: Estudio descriptivo, transversal y retrospectivo que se incluyeron 118 recién nacidos pretérmino (RNPT) e excluyó a 25 sobrevivientes por ser referidos a otras instituciones, padecer de malformaciones congénitas o tener su ficha clínica incompleta. Se registró su evolución con respecto de la ocurrencia de ROP en los siguientes seis controles posterior a su nacimiento. Resultados: De los 118 RN con bajo peso al nacer, al final del período de estudio el 50.8% (60) evolucionaron en hacia la regresión espontánea con diagnóstico previo de ROP y en 16,9% (20) a estadios que necesitaron tratamiento con laserterapia, el restante 32,2% (38) tuvo buenos resultados con fondo de ojo normal (retina madura) previo a un diagnóstico de retina inmadura. Se encontró diferencia significativa en el promedio del peso al nacer (p˂0,001, análisis de varianza) en los tres grupos estudiados. No se evidenció diferencias significativas entre la evolución de los RN por sexo. Conclusiones: Se encontró una frecuencia de 42% de ROP en los RNPT evaluados. Una asociación entre peso del RN y la necesidad de requerir laserterapia. En los RN de sexo masculino aprox. el 55% se ven curados durante el tercer control mientras que el sexo femenino lo hicieron en un 45 %

Fault-tolerant unfalsified control for PEM fuel cell systems

The article addresses the implementation of a data-driven control strategy in a real test bench based on proton exchange membrane fuel cells (PEMFCs). The proposed control scheme is based on Unfalsified Control (UC), which allows adapting in real-time the control law by evaluating the performance specifications based only on measured input-output data. This approach is especially suitable to deal with non-linearity, model uncertainty and also possible faults that may occur in PEMFCs. The control strategy has been applied to several experimental practical situations in order to evaluate not only the system performance but also different fault scenarios. The experimental results have shown the effectiveness of the proposed approach to regulate the oxygen stoichiometry in real-time operation as well as to maintain a proper system performance under fault situations. Also, a start-up mass-flow controller is added in order to bring the system towards its normal operating conditions.Peer ReviewedPostprint (author’s final draft

Satisfacción laboral en los médicos del primer nivel de atención en la Región Lambayeque, 2014

Objetivo: Medir el grado de satisfacción laboral de médicos del primer nivel de atención según características sociales y laborales en la región Lambayeque de septiembre a diciembre del 2014. Materiales y métodos: Estudio descriptivo y prospectivo. La población consta de 258 médicos generales; con la calculadora estadística “EPIDAT” versión 3.1, obtuvo un tamaño de muestra de 155 médicos, con un nivel de confianza del 95%, precisión del 5% y una proporción esperada de la variable resultado del 50%. Utilizando el cuestionario elaborado por Font-Roja de satisfacción laboral. Resultados: La edad promedio fue 39,2 ±7,4 años; el 61,7% fueron hombres y 38,3% mujeres. Se encontró un grado de satisfacción laboral medio alto de 14,24. La satisfacción laboral es mayor en mayores de 40 años (p=0,044), y mayor en divorciados (p=0,012). La tensión relacionada con el trabajo es mayor en hombres (p=0,001). La competencia profesional es mayor en médicos provenientes de universidad privada (p=0,043). La presión en el trabajo es mayor en médicos que tienen maestría con título (p=0,002), La relación interpersonal con superiores es mayor en médicos mayores de 40 años (p=0,015) y mayor con contrato DL 276 (p=0,033). El status es mayor en los que tienen maestría con título (p=0,048) y provenientes de universidad privada (p=0,048). Conclusiones: La satisfacción laboral aumenta en médicos mayores, y aumenta en los médicos que son divorciados, también encontramos presión en el trabajo en profesionales con grado académico adicional, la relación con los jefes es mejor entre médicos mayores, y el status está relacionado con el grado académico y de una universidad privad

Consumo de alcohol y tabaco en estudiantes de medicina en departamento de Lambayeque

Objetivo: Estimar el nivel de consumo de alcohol y tabaco entre los estudiantes de medicina en el departamento de Lambayeque. Material y Métodos: se realizó un estudio de tipo cuantitativo descriptivo – transversal. La muestra estuvo formada por 464 estudiantes elegidos por muestreo aleatorio estratificado con fijación proporcional. Se utilizó el Cuestionario para la Clasificación de Consumidores de Cigarrillo (C4), y un cuestionario AUDIT el cual se le proporcionó a cada alumno que forme parte de la investigación. Resultados: La frecuencia de consumo de riesgo de alcohol en los estudiantes encuestados fue 70,47%, solo un 5,6% llegó a tener consumo perjudicial y 1 estudiante presentó posible dependencia de alcohol (0,22%). La prevalencia del consumo de alcohol en varones fue 55,37% y 44,63% en mujeres. La edad media fue 21,7 años en los que consumen. Los estudiantes que no fuman o nunca 353 (76,1%), con nivel bajo de consumo de cigarrillos 0 (cero), con nivel moderado 92 (19,8%), con tendencia a la dependencia 19 (4,1%), con dependencia 0 (cero). La prevalencia del consumo de tabaco en varones fue de 35,14% y 13,64% en mujeres. La edad media fue de 21,58 años en los que fuman. Conclusiones: El nivel de consumo de alcohol en los estudiantes de medicina del departamento de Lambayeque fue de riesgo. El nivel de consumo de tabaco en los estudiantes de medicina fue moderado