Switching Adaptive Concurrent Learning Control for Powered Rehabilitation Machines with FES

Interfacing robotic devices with humans presents significant control challenges, as the control algorithms governing these machines must accommodate for the inherent variability among individuals. This requirement necessitates the system’s ability to adapt to changes in the environment, particularly in the context of human-in-the-loop applications, wherein the system must identify specific features of the human interacting with the machine. In the field of rehabilitation, one promising approach for exercise-based rehabilitation involves the integration of hybrid rehabilitation machines, combining robotic devices such as motorized bikes and exoskeletons with functional electrical stimulation (FES) applied on lower-limb muscles. This integrated approach offers the potential for repetitive training, reduced therapist workload, improved range of motion, and therapeutic benefits. However, conducting prolonged rehabilitation sessions to maximize functional recovery using these hybrid machines imposes several difficulties. Firstly, the design and analysis of adaptive controllers are motivated, but challenges exist in coping with the inherent switching effects associated with hybrid machines. Notably, the transitions between gait phases and the dynamic switching of inputs between active lower-limb muscles and electric motors and their incorporation in the control design remain an open problem for the research community. Secondly, the system must effectively compensate for the influence of human input, which can be viewed as an external disturbance in the closed-loop system during rehabilitation. Robust methods for understanding and adapting to the variations in human input are critical for ensuring stability and accurate control of the human-robot closed-loop system. Lastly, FES-induced muscle fatigue diminishes the human torque contribution to the rehabilitation task, leading to input saturation and potential instabilities as the duration of the exercise extends. Overcoming this challenge requires the development of control algorithms that can adapt to variations in human performance by dynamically adjusting the control parameters accordingly. Consequently, the development of rehabilitative devices that effectively interface with humans requires the design and implementation of control algorithms capable of adapting to users with varying muscle and kinematic characteristics. In this regard, adaptive-based control methods provide tools for addressing the uncertainties in human-robot dynamics within exercise-based rehabilitation using FES, while ensuring stability and robustness in the human-robot closed-loop system. This dissertation develops adaptive controllers to enhance the effectiveness of exercise-based rehabilitation using FES. The objectives include the design and evaluation of adaptive control algorithms that effectively handle the switching effects inherent in hybrid machines, adapt to compensate for human input, and account for input saturation due to muscle fatigue. The control designs leverage kinematic and torque feedback and ensure the stability of the human-robot closed-loop system. These controllers have the potential to significantly enhance the practicality and effectiveness of assistive technologies in both clinical and community settings. In Chapter 1, the motivation to design switching adaptive closed-loop controllers for motorized FES-cycling and powered exoskeletons is described. A survey of closed-loop kinematic control methods related to the tracking objectives in the subsequent chapters of the dissertation is also introduced. In Chapter 2, the dynamic models for cycling and bipedal walking are described: (i) a stationary FES-cycling model with nonlinear dynamics and switched control inputs are introduced based on published literature. The muscle stimulation pattern is defined based on the kinematic effectiveness of the rider, which depends on the crank angle. (ii) A phase-dependent bipedal walking system model with switched dynamics is introduced to control a 4-degrees-of-freedom (DoF) lower-limb exoskeleton assuming single stance support. Moreover, the experimental setup of the cycle-rider and lower-limb exoskeleton system are described. Chapter 3 presents a switched concurrent learning adaptive controller for cadence tracking using the cycle-rider model. The control design is decoupled for the muscles and electric motor. An FES controller is developed with minimal parameters, capable of generating bounded muscle responses with an adjustable saturation limit. The electric motor controller employs an adaptive-based method that estimates uncertain parameters in the cycle-rider system and leverages the muscle input as a feedforward term to improve the tracking of crank trajectories. The adaptive motor controller and saturated muscle controller are implemented in able-bodied individuals and people with movement disorders. Three cycling trials were conducted to demonstrate the feasibility of tracking different crank trajectories with the same set of control parameters across all participants. The developed adaptive controller requires minimal tuning and handles rider uncertainty while ensuring predictable and satisfactory performance. This result has the potential to facilitate the widespread implementation of adaptive closed-loop controllers for FES-cycling systems in real clinical and home-based scenarios. Chapter 4 presents an integral torque tracking controller with anti-windup compensation, which achieves the dual objectives of kinematic and torque tracking (i.e., power tracking) for FES cycling. Designing an integral torque tracking controller to avoid feedback of high-order derivatives poses a significant challenge, as the integration action in the muscle loop can induce error buildup; demanding high FES input on the muscle. This can cause discomfort and accelerate muscle fatigue, thereby limiting the practical utility of the power tracking controller. To address this issue, this chapter builds upon the adaptive control for cadence tracking developed in Chapter 3 and integrates a novel torque tracking controller that allows for input saturation in the FES controller. By doing so, the controller achieves cadence and torque tracking while preventing error buildup. The analysis rigorously considers the saturation effect, and preliminary experimental results in able-bodied individuals demonstrate its feasibility. In Chapter 5, a switched concurrent learning adaptive controller is developed to achieve kinematic tracking throughout the step cycle for treadmill-based walking with a 4-DoF lower-limb hybrid exoskeleton. The developed controller leverages a phase-dependent human-exoskeleton model presented in Chapter 2. A multiple-Lyapunov stability analysis with a dwell time condition is developed to ensure exponential kinematic tracking and parameter estimation. The controller is tested in two able-bodied individuals for a six-minute walking trial and the performance of the controller is compared with a gradient descent classical adaptive controller. Chapter 6 highlights the contributions of the developed control methods and provides recommendations for future research directions

Diplomado de profundización cisco ccnp solución de dos escenarios presentes en entornos corporativos bajo el uso de tecnología cisco

Se plantean 2 escenarios en los cuales se debe tener conectividad entre los distintos dispositivos router cumpliendo una serie de condiciones las cuales refuerzan los conocimientos obtenidos con la configuración de protocolos en red y realizar la compatibilidad de los mismos e interconectar distintos hosts por medio de una topología de red redundante de distintos dispositivos de red en diferentes protocolos como OSPF ,EIGRP para así tener alta disponibilidad con canales redundantes entre los dispositivos de una topología la cual debe cumplir con los parámetros indicados EtherChannel, Vlan. Todo esto se realiza con configuración de las distintas áreas y protocolos OSPF ,EIGRP en el cual uno de los dispositivos se utiliza como puente entre los dos protocolos para así tener una conectividad de punta a punta, y otro escenario se encuentra la solución por medio de puertos troncales y EtherChannel damos la conectividad de distintas vlan en una red con una alta disponibilidad gracias a sus canales redundantes los cuales nos aseguran la conectividad entre dispositivos a pesar de posibles fallas de red o caídas.Two scenarios are proposed in which there must be connectivity between the different router devices fulfilling a series of conditions which reinforce the knowledge obtained with the configuration of network protocols and make their compatibility and interconnect different hosts through a topology Redundant network of different network devices in different protocols such as OSPF, EIGRP in order to have high availability with redundant channels between the devices of a topology which must comply with the indicated parameters EtherChannel, Vlan. All this is done with the configuration of the different areas and protocols OSPF, EIGRP in which one of the devices is used as a bridge between the two protocols in order to have end-to-end connectivity, and another scenario finds the solution through trunk ports and EtherChannel we provide the connectivity of different vlan in a network with high availability thanks to its redundant channels which ensure connectivity between devices despite possible network failures or drops

A User-Level Process Package for Concurrent Computing

A lightweight user-level process(ULP) package for parallel computing is described. Each ULP has its own register context, stack, data and heap space and communication with other ULPs is performed using locally synchronous, location transparent, message passing primitives. The aim of the package is to provide support for lightweight over-decomposition, optimized local communication and transparent dynamic migration. The package supports a subset of the Parallel Virtual Machine(PVM) interface[Sun90)

Eye Coinfections

Ocular infections are an ophthalmologic emergency that threatens the eye’s integrity, which may result in a poor visual outcome; hence, it requires prompt treatment. The most common microorganisms involved in eye infection are the bacteria, followed by virus and fungi; however the prevalence depends on the geographic location. It is essential to know The etiologic agent of the ocular infection ocular infections and their antibiotic sensitivity because the geographical situation and the urbanization level of the studied population will determine their prevalence. Recently have been described eye coinfections, where at least two microorganisms can infect at the same time and the same anatomic site. Several coinfections have been published, bacteria-bacteria, bacteria-fungus, bacteria-virus, fungus-yeast, fungus-virus, parasite-bacteria, etc. Eye coinfections represent a particular challenge for the ophthalmologists; coinfections are difficult to diagnose because often the clinical characteristic is atypical and mimics different clinical pictures. In addition, eye coinfections respond poorly to antibiotics and usually present an aggressive clinical course. In these circumstances, it is common for patients to receive multiple treatments when they should be receiving a specific treatment. Several risk factors are important to develop coinfections, e.g., trauma, dry eye, use of contact lenses, and comorbidities (diabetes and immunosuppression). Coinfections have been described in keratitis, conjunctivitis, and endophthalmitis. The study of polymicrobial biofilms has been increasing, and in the medical area, the role played by biofilms in confections has been associated with virulence factors; hence, biofilm formation is also considered a determinant virulence factor for pathogenesis in the host. Coinfection diagnosis is an important topic in order to obtain a specific and timely diagnosis. Microbiological and molecular approaches are proposed to identify etiological agents. Delay in diagnosis affects the sensitivity to specific treatments and the evolution of infection. Treatment and prognosis are supported by a specific diagnosis

Análisis de modelos matemáticos para el comportamiento de dos microorganismos en un proceso de fermentación

El comportamiento de los microorganismos que interactúan en un proceso de fermentación requiere de la utilización de diferentes modelos matemáticos.  Para el análisis de dos microorganismos en un proceso de fermentación se proponen tres modelos matemáticos, con el objetivo de analizar la interacción que desempeñan las bacterias en el medio donde se desarrollan. Para cada modelo se cuantificó Biomasas, Sustratos y Productos. Se utilizan tablas y gráficas de los  modelos propuestos para observar el comportamiento que efectúan dos microorganismos en un proceso de fermentación

IP3R-driven increases in mitochondrial Ca2+ promote neuronal death in NPC disease

Ca2+ is the most ubiquitous second messenger in neurons whose spatial and temporal elevations are tightly controlled to initiate and orchestrate diverse intracellular signaling cascades. Numerous neuropathologies result from mutations or alterations in Ca2+ handling proteins; thus, elucidating molecular pathways that shape Ca2+ signaling is imperative. Here, we report that loss-of-function, knockout, or neurodegenerative disease-causing mutations in the lysosomal cholesterol transporter, Niemann-Pick Type C1 (NPC1), initiate a damaging signaling cascade that alters the expression and nanoscale distribution of IP3R type 1 (IP3R1) in endoplasmic reticulum membranes. These alterations detrimentally increase Gq-protein coupled receptor-stimulated Ca2+ release and spontaneous IP3R1 Ca2+ activity, leading to mitochondrial Ca2+ cytotoxicity. Mechanistically, we find that SREBP-dependent increases in Presenilin 1 (PS1) underlie functional and expressional changes in IP3R1. Accordingly, expression of PS1 mutants recapitulate, while PS1 knockout abrogates Ca2+ phenotypes. These data present a signaling axis that links the NPC1 lysosomal cholesterol transporter to the damaging redistribution and activity of IP3R1 that precipitates cell death in NPC1 disease and suggests that NPC1 is a nanostructural disease

The Light Higgsino-Gaugino Window

Supersymmetric models are typically taken to have $\mu$ parameter and all soft supersymmetry breaking parameters at or near the weak scale. We point out that a small window of allowed values exists in which $\mu$ and the electroweak gaugino masses are in the few GeV range. Such models naturally solve the supersymmetry $CP$ problem, can reduce the discrepancy in $R_b$, and suppress proton decay. In this window two neutralinos are in the few GeV range, two are roughly degenerate with the $Z^0$, and both charginos are roughly degenerate with the $W^{\pm}$ bosons. Such a signature cannot escape detection at LEP II. Models that fall in this window automatically arise from renormalizable hidden sectors in which hidden sector singlets participate only radiatively in supersymmetry breaking.Comment: 14pp, ReVTeX, 3 uuencoded figures. R_b discussion corrected, references adde

Evaluación de riesgos, monitorización y simulación de edificios patrimoniales

Los edificios religiosos son una parte importante del patrimonio cultural, son documentos de nuestra herencia y tenemos la necesidad de preservarlos. Las condiciones ambientales en el que están inmersos estos edificios son determinantes para la preservación y conservación del patrimonio mueble que contiene. Originalmente, la mayoría de estos espacios no estaban acondicionados, pero actualmente, estos edificios están siendo climatizados para proporcionar el confort térmico a los feligreses y para mejorar las condiciones del clima interior y la preservación del patrimonio mueble. El objetivo principal de esta investigación ha sido analizar las condiciones ambientales de edificios religiosos en un clima Mediterráneo, mediante el uso de monitorización y simulación para evaluar y mejorar la preservación del patrimonio cultural de estos edificios. Este estudio aporta las herramientas para la optimización de la calidad ambiental para la preservación y conservación del patrimonio mueble e inmueble y para su aplicación en futuros proyectos de rehabilitación patrimonial.The churches are an important part of Cultural Heritage; these need to be preserved. The indoor environmental conditions of these spaces are decisive for the preservation and conservation of the movable heritage The originally churches were not conditioned, but currently, these buildings are being air-conditioned to provide thermal comfort to parishioners and to improve indoor weather conditions. The main objective of this research project has been to analyse the environmental conditions of religious buildings in a Mediterranean climate, through the use of monitoring and simulation to evaluate and improve the preservation of the Cultural Heritage of these buildings. Finally, this study provides the subject expert, the tools for the optimization of environmental and energy quality, in the refurbishment project