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  • Artículo de Publicación Periódica
    Open-source navigation system for tracking dissociated parts with multi-registration
    (2021) Mancino, A. V.; Milano, F. E.; Risk, M. R.; Ritacco, L. E.
    Purpose: During reconstructive surgery, knee and hip replacements, and orthognathic surgery, small misalignments in the pose of prosthesis and bones can lead to severe complications. Hence, the translational and angular accuracies are critical. However, traditional image-based surgical navigation lacks orientation data between structures, and imageless systems are unsuitable for cases of deformed anatomy. We introduce an open-source navigation system using a multiple registrations approach that can track instruments, implants, and bones to precisely guide the surgeon in emulating a preoperative plan. Methods: We derived the analytical error of our method and designed a set of phantom experiments to measure its precision and accuracy. Additionally, we trained two classification models to predict the system reliability from fiducial points and surface matching registration data. Finally, to demonstrate the procedure feasibility, we conducted a complete workflow for a real clinical case of a patient with fibrous dysplasia and anatomical misalignment of the right femur using plastic bones. Results: The system is able to track the dissociated fragments of the clinical case and averages alignment errors in the anatomical phantoms of 1.08 ± 0.68mm and 1.49 ± 1.19°. While the fiducial-points registration showed satisfactory results given enough points and covered volume, we acknowledge that the surface refinement step is mandatory when attempting surface matching registrations. Conclusion: We believe that our device could bring significant advantages for the personalized treatment of complex surgical cases and that its multi-registration attribute is convenient for intraoperative registration loosening cases.
  • Artículo de Publicación Periódica
    Controlling neural activity: LPV modelling of optogenetically actuated Wilson-Cowan model
    (2024) Martínez, S.; Sánchez-Peña, R. S.; García-Violini, D.
    This paper aims to bridge the gap between neurophysiology and automatic control methodologies by redefining the Wilson-Cowan (WC) model as a control-oriented linear parameter-varying (LPV) system. A novel approach is presented that allows for the application of a control strategy to modulate and track neural activity. Approach: The WC model is redefined as a control-oriented LPV system in this study. The LPV modelling framework is leveraged to design an LPV controller, which is used to regulate and manipulate neural dynamics. Main results: Promising outcomes, in understanding and controlling neural processes through the synergistic combination of control-oriented modelling and estimation, are obtained in this study. An LPV controller demonstrates to be effective in regulating neural activity. Significance: The presented methodology effectively induces neural patterns, taking into account optogenetic actuation. The combination of control strategies with neurophysiology provides valuable insights into neural dynamics. The proposed approach opens up new possibilities for using control techniques to study and influence brain functions, which can have key implications in neuroscience and medicine. By means of a model-based controller which accounts for non-linearities, noise and uncertainty, neural signals can be induced on brain structures.
  • Artículo de Publicación Periódica
    The impact of the succesive outbreaks of COVID-19, vaccination, and physical activity on mental health in the argentine population : a repeated cross-sectional study
    (2024-02-26) Barbuzza, Alejo Ramiro; Ballarini, Fabricio; Goyeneche, Celina; Reppucci, Victoria; Benedetti, Pedro; Moscato, Franco; Medina, Jorge H.; Katche, Cynthia; Moncada, Diego; Viola, Haydeé
    A controversy regarding the duration of generalized anxiety disorders (GAD) and depressive symptoms during the COVID-19 pandemic arose, stating that these symptoms last a short time, perhaps a few months, or that they are more persistent over time. After more than three years of the pandemic, this is still a question that requires an answer. The main goal of this work was to record the levels of self-perceived GAD and depression in the Argentine population at several time points during the pandemic to characterize whether they were transient or persisted over the successive waves of contagion. Furthermore, we studied the association between anti-COVID-19 vaccination and the high frequency of physical activity with GAD and depression levels to evaluate a possible protective role of these factors on mental health.
  • Artículo de Publicación Periódica
    Enhanced retention of bacteria by TiO2 nanoparticles in saturated porous media
    (2016) Gentile, Guillermina J.; Fidalgo de Cortalezzi, María M.
    The simultaneous transport of TiO2 nanoparticles and bacteria Pseudomonas aeruginosa in saturated porous media was investigated. Nanoparticle and bacterium size and surface charge were measured as a function of electrolyte concentration. Sand column breakthrough curves were obtained for single and combined suspensions, at four different ionic strengths. DLVO and classical filtration theories were employed to model the interactions between particles and between particles and sand grains. Attachment of TiO2 to the sand was explained by electrostatic forces and these nanoparticles acted as bonds between the bacteria and the sand, leading to retention. Presence of TiO2 significantly increased the retention of bacteria in the sand bed, but microorganisms were released when nanomaterial influx ceased. The inclusion of nanomaterials in saturated porous media may have implications for the design and operation of sand filters in water treatment.
  • Artículo de Publicación Periódica
    Detection of atypical response trajectories in biomedical longitudinal databases
    (De Gruyter, 2022-10-24) Pantazis, Lucio José; García, Rafael Antonio
    Many health care professionals and institutions manage longitudinal databases, involving follow-ups for different patients over time. Longitudinal data frequently manifest additional complexities such as high variability, correlated measurements and missing data. Mixed effects models have been widely used to overcome these difficulties. This work proposes the use of linear mixed effects models as a tool that allows to search conceptually different types of anomalies in the data simultaneously.
  • Artículo de Publicación Periódica
    Online adjustable linear parameter-varying controller for artificial pancreas systems
    (Elsevier, 2023-06) Bianchi, Fernando D.; Sánchez-Peña, Ricardo; Garelli, Fabricio
    The purpose of this article is to present a non-hybrid fully closed-loop controller for the Artificial Pancreas (AP) problem focused on long-term clinical trials and home-use applications. It includes physical activity (PA) and unannounced meals. The controller is based on a robust gain-scheduled algorithm with a Linear Parameter-Varying (LPV) structure. It takes into account the time-varying dynamics of the problem by adapting itself in real-time according to measured glucose levels, and allows online fine-tuning during tests and periodic evaluations without the need of a controller redesign. The proposed fully parameterized LPV control adds several features to our previous results, accounts for the main perturbations of the AP problem and simplifies its implementation. To help in the parameter fine-tuning, a methodology based on clinical information is proposed. In-silico tests show that the achieved performance is similar or better than our previous Automatic Regulation of Glucose (ARG) algorithm, tested in two clinical trials, with the addition of the features mentioned before.
  • Artículo de Publicación Periódica
    Field Evaluation of Novel Spatial Repellent Controlled Release Devices (CRDs) against Mosquitoes in an Outdoor Setting in the Northern Peruvian Amazon
    (Tropical Medicine and Infectious Disease, 7(11), 372. MDPI AG, 2022) Flores-Mendoza, Carmen; López-Sifuentes, Victor M.; Vásquez, Gissella M.; Stoops, Craig A.; Fisher, Michael L.; Bernier, Ulrich R.; Perry, Melynda; Mollica, Juan; Coltzau, Damián A.; Gurman, Pablo; D’hers, Sebastián; Elman, Noel M.
    U.S. military troops are exposed to mosquito-borne pathogens when deployed to endemic regions. Personal protective measures such as permethrin-treated uniforms and dermal repellents are the cornerstones of mosquito-borne disease prevention for the U.S. military. These measures have limitations and additional personal protection tools, such as spatial repellent devices to decrease the risk of vector-borne pathogen transmission, are required. Novel spatial repellent controlled-release devices formulated with metofluthrin were evaluated in an outdoor setting in the northern Amazon of Peru to evaluate performance under field conditions. The metofluthrin emitting devices lowered the number of mosquitoes captured in protected human landing collections (HLC) compared to blank devices, although there were effect differences between Anopheles spp. and species in other mosquito genera. A computational-experimental model was developed to correlate HLC and active ingredient (AI) concentrations as a function of time and space. Results show a strong correlation between the released AI and the decrease in HLC. This model represents the first effort to obtain a predictive analytical tool on device performance using HLC as the entomological endpoint.
  • Artículo de Publicación Periódica
    Spatial repellents transfluthrin and metofluthrin affect the behavior of Dermacentor variabilis, Amblyomma americanum, and Ixodes scapularis in an in vitro vertical climb assay
    (Plos One, 2022) Siegel, Eric L.; Olivera, Marcos; Martínez Roig, Esteban; Perry, Melynda; Li, Andrew Y.; D'hers, Sebastián; Elman, Noel M.; Rich, Stephen M.
    Repellents serve an important role in bite protection. Tick repellents largely rely on biomechanisms that induce responses with direct contact, but synthetic pyrethroids used as spatial repellents against insects have received recent attention for potential use in tick protection systems. An in vitro vertical climb assay was designed to assess spatial repellency against Dermacentor variabilis, Amblyomma americanum, and Ixodes scapularis adult, female ticks. Climbing behavior was assessed with and without the presence of two spatial repellents, transfluthrin and metofluthrin. Repellency parameters were defined to simulate the natural questing behavior of ambushing ticks, including measures of detachment, pseudo-questing duration, climbing deterrence, and activity. Significant effects were observed within each parameter. D. variabilis showed the greatest general susceptibility to each repellent, followed by A. americanum, and I. scapularis. The most important and integrative measure of repellency was climbing deterrence–a measure of the spatial repellent’s ability to disrupt a tick’s natural propensity to climb. Transfluthrin deterred 75% of D. variabilis, 67% of A. americanum, and 50% of I. scapularis. Metofluthrin was slightly more effective, deterring 81% of D. variabilis, 73% of A. americanum, and 72% of I. scapularis. The present study poses a novel paradigm for repellency and reports a preliminary assessment of spatial repellent effect on tick behavior. Further research will assess spatial repellency in a more natural setting, scale exposure conditions, and incorporate host cues.
  • Artículo de Publicación Periódica
    Non-pharmaceutical intervention to reduce COVID-19 impact in Argentina
    (2022-05) García Violini, Demián; Sánchez-Peña, Ricardo; Moscoso-Vásquez, Marcela; Garelli, Fabricio
    "This work is focused on the multilevel control of the population confinement in the city of Buenos Aires and its surroundings due to the pandemic generated by the COVID-19 outbreak. The model used here is known as SEIRD and two objectives are sought: a time-varying identification of the infection rate and the inclusion of a controller. A control differential equation has been added to regulate the transitions between confinement and normal life, according to five different levels. The plasma treatment from recovered patients has also been considered in the control algorithm. Using the proposed strategy the ICU occupancy is reduced, and as a consequence, the number of deaths is also decreased."
  • Artículo de Publicación Periódica
    Second wave of COVID-19 pandemic in Argentinian population: vaccination is associated with a decrease in depressive symptoms
    (2022-06) Benedetti, Pedro; Barbuzza, Alejo; Moscato, Franco; Reppucci, Victoria; Goyeneche, Celina; Katche, Cynthia; Medina, Jorge Horacio; Viola, Haydeé; Ballarini, Fabricio; Moncada, Diego
    "Since the irruption of the coronavirus disease 2019 (COVID-19) the planet has submerged in a time of concern and uncertainty, with a direct impact on people's mental health. Moreover, the recurrent outbreaks that periodically harry different regions of the world constantly refocus people's concerns to the pandemic. Yet, each new wave heats the diverse countries in different situations, including the advances in their vaccination campaigns. In this research, we studied the levels of the general anxiety disorder (GAD) and depression in the Argentine population across the first and second waves of infections that occurred in our country."
  • Artículo de Publicación Periódica
    Control no-híbrido de glucemia ensayado en pacientes ambulatorios con Diabetes Tipo 1
    (2022-07) Garelli, Fabricio; Fushimi, Emilia; Rosales, Nicolás; Arambarri, Delfina; Serafini, María Cecilia; De Battista, Hernán; Grosembacher, Luis; Sánchez-Peña, Ricardo
    "En este trabajo se presenta la experiencia argentina en el problema de regulación de los niveles de glucosa en sangre para pacientes con Diabetes Mellitus Tipo 1 (insulino-dependientes), denominado Páncreas Artificial. El grupo de trabajo ha realizado 3 pruebas clínicas, las primeras en Latinoamérica. Las dos primeras fueron concretadas en 2016 y 2017, ambas en el Hospital Italiano de Buenos Aires (HIBA) con 5 pacientes adultos durante 36 hs. En la segunda de ellas se utilizó un nuevo algoritmo de control de lazo cerrado puro (sin bolo prandial), llamado ARG (Automatic Regulation of Glucose) y basado en un control LQG conmutado en combinación con una capa de seguridad llamada SAFE (Safety Auxiliary Feedback Element). Más recientemente y en plena pandemia de COVID-19 se llevó a cabo la primera prueba ambulatoria, realizada en 2021 en un hotel con 5 pacientes durante 6 días. En esta tercera prueba además, se utilizó una plataforma desarrollada por la Universidad Nacional de La Plata (UNLP), denominada InsuMate. Ésta conecta el celular con la bomba de insulina y el monitor de glucosa, aloja el algoritmo de control y permite el monitoreo remoto de múltiples pacientes. Los resultados obtenidos sugieren que el uso del algoritmo ARG en forma ambulatoria es factible, seguro y eficaz en comparación con la terapia usual. Asimismo, la plataforma InsuMate resultó ser intuitiva y sencilla para los usuarios, tanto médicos como pacientes participantes del ensayo, logrando un tiempo de funcionamiento del lazo cerrado superior al 95 %."
  • Artículo de Publicación Periódica
    First outpatient clinical trial of a full closed-loop artificial pancreas system in South America
    (2022-05) Garelli, Fabricio; Fushimi, Emilia; Rosales, Nicolás; Arambarri, Delfina; Mendoza, Leandro; Serafini, María Cecilia; Moscoso-Vásquez, Marcela; Stasi, Marianela; Duette, Patricia; García Arabehety, Julia; Giunta, Javier; De Battista, Hernán; Sánchez-Peña, Ricardo; Grosembacher, Luis
    "The first two studies of an artificial pancreas (AP) system carried out in Latin America took place in 2016 (phase 1) and 2017 (phase 2). They evaluated a hybrid algorithm from the University of Virginia (UVA) and the automatic regulation of glucose (ARG) algorithm in an inpatient setting using an AP platform developed by the UVA. The ARG algorithm does not require carbohydrate (CHO) counting and does not deliver meal priming insulin boluses. Here, the first outpatient trial of the ARG algorithm using an own AP platform and doubling the duration of previous phases is presented."
  • Artículo de Publicación Periódica
    A method for reducing implementation complexity in linear parameter-varying controllers
    (2022-12) Bianchi, Fernando D.; Sánchez-Peña, Ricardo
    "Gain-scheduling is a popular control technique to deal with nonlinear and time varying systems. The linear parameter-varying (LPV) system approach offers systematic tools to design gain-scheduled controllers. However, the implementation of these controllers might demand complex mathematical operations to be performed in real-time. This limits the hardware and the applications in which LPV controllers can be used. In this article, we analyze these limitations and propose a design methodology to reduce the implementation complexity of gain-scheduled LPV controllers. The methodology is illustrated with a nonlinear bicycle model used in electric vehicle control."
  • Artículo de Publicación Periódica
    Remote glucose monitoring platform for multiple simultaneous patients at coronavirus disease 2019 intensive care units: case report including adults and children
    (2021) Garelli, Fabricio; Rosales, Nicolás; Fushimi, Emilia; Arambarri, Delfina; Mendoza, Leandro; De Battista, Hernán; Sánchez-Peña, Ricardo; García Arabehety, Julia; Distefano, Sabrina; Barcala, Consuelo; Giunta, Javier; Las Heras, Marcos; Martínez Mateu, Carolina; Prieto, Mariana; San Román, Eduardo; Krochik, Gabriela; Grosembacher, Luis
  • Artículo de Publicación Periódica
    Reducing glucose variability due to meals and postprandial exercise in TI DM using switched LPV control: in silico studies
    (2016) Colmegna, Patricio; Sánchez-Peña, Ricardo; Gondhalekar, Ravi; Dassau, Eyal; Doyle III, Frank J.
    "Time-varying dynamics is one of the main issues for achieving safe blood glucose control in type I diabetes mellitus (TI DM) patients. In addition, the typical disturbances considered for controller design are meals, which increase the glucose level, and physical activity (PA), which increases the subject's sensitivity to insulin. In previous works the authors have applied a linear parameter-varying (LPV) control technique to manage unannounced meals."
  • Artículo de Publicación Periódica
    Switched LPV glucose control in type 1 diabetes
    (2016-06) Colmegna, Patricio; Sánchez-Peña, Ricardo; Gondhalekar, Ravi; Dassau, Eyal; Doyle III, Frank J.
    "The purpose of this work is to regulate the blood glucose level in Type 1 Diabetes Mellitus (T1DM) patients with a practical and flexible procedure that can switch amongst a finite number of distinct controllers, depending on the user´s choice."
  • Artículo de Publicación Periódica
    Non-pharmaceutical intervention to reduce COVID-19 impact in Argentina
    (2021-06-21) García Violini, Demián; Sánchez-Peña, Ricardo; Moscoso-Vásquez, Marcela; Garelli, Fabricio
    "This work is focused on the multilevel control of the population confinement in the city of Buenos Aires and its surroundings due to the pandemic generated by the COVID-19 outbreak. The model used here is known as SEIRD and two objectives are sought: a time-varying identification of the infection rate and the inclusion of a controller. A control differential equation has been added to regulate the transitions between confinement and normal life, according to five different levels. The plasma treatment from recovered patients has also been considered in the control algorithm. Using the proposed strategy the ICU occupancy is reduced, and as a consequence, the number of deaths is also decreased."
  • Artículo de Publicación Periódica
    Automated detection and quantification of reverse triggering efort under mechanical ventilation
    (2021-02-15) Pham, Tài; Montanya, Jaume; Telias, Irene; Piraino, Thomas; Magrans, Rudys; Coudroy, Rémi; Damiani, L. Felipe; Mellado Artigas, Ricard; Madorno, Matías; Blanch, Lluis; Brochard, Laurent
    "Reverse triggering (RT) is a dyssynchrony defned by a respiratory muscle contraction following a passive mechanical insufation. It is potentially harmful for the lung and the diaphragm, but its detection is challenging. Magnitude of efort generated by RT is currently unknown. Our objective was to validate supervised methods for automatic detection of RT using only airway pressure (Paw) and fow. A secondary objective was to describe the magnitude of the eforts generated during RT."
  • Artículo de Publicación Periódica
    Prevalence of reverse triggering in early ARDS: results from a multicenter observational study
    (2021-01) Rodríguez, Pablo Oscar; Tiribelli, Norberto; Fredes, Sebastián; Gogniat, Emiliano; Plotnikow, Gustavo A.; Fernández Ceballos, Ignacio; Pratto, Romina A.; Raimondi, Alejandro C.; Guaymas, María; Ilutovich, Santiago; San Román, Eduardo; Madorno, Matías; Maskin, Luis Patricio; Brochard, Laurent; Setten, Mariano
    "Background: The prevalence of reverse triggering (RT) in the early phase of ARDS is unknown. Research question: During early ARDS, what is the proportion of patients affected by RT, what are its potential predictors, and what is its association with clinical outcomes? Study design and methods: This was prospective, multicenter, and observational study. Patients who met the Berlin definition of ARDS with less than 72 h of mechanical ventilation and had not been paralyzed with neuromuscular blockers were screened. A 30-min recording of respiratory signals was obtained from the patients as soon as they were enrolled, and the number of breaths with RT were counted."
  • Artículo de Publicación Periódica
    Automatic glucose control during meals and exercise in type 1 diabetes: proof-of-concept in silico tests using a switched LPV approach
    (2021) Colmegna, Patricio; Bianchi, Fernando D.; Sánchez-Peña, Ricardo
    "Keeping the blood glucose levels within the safe range during meals and exercise still represents a major hurdle not only for patients with type 1 diabetes (T1D), but also for Artificial Pancreas (AP) systems. One of the reasons a fully (autonomous) closed-loop solution has not been released onto the market yet is the slow action of current insulin analogs. To partially overcome this limitation, the authors have previously designed a switched control strategy equipped with an insulin-on-board (IOB) safety loop that mitigates meal-related glucose excursions without carbohydrate counting. In this paper, a similar strategy based on a Linear Parameter-Varying (LPV) control law has been adapted to safely handle also exercise challenges with minimum user intervention. In silico results using the UVA/Padova simulator evidence that the proposed closedloop scheme is feasible under moderate-intense exercise bouts by effectively and safely reducing the risk of hypoglycemia."