Bioingeniería

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Herramienta web para post-análisis de simulaciones de dinámica molecular
(2013) Borgna, Karina Giselle; Fernández, María Laura; Risk, Marcelo
"En este trabajo se busca desarrollar una aplicación web interactiva y personalizada que permita analizar resultados generados mediante simulaciones de dinámica molecular. Con esta herramienta se pretende analizar las propiedades cada átomo o molécula de manera individual o conjunta a partir de una trayectoria, permitiendo segmentaciones tridimensionales que el usuario puede personalizar, así como análisis estadísticos no disponibles en las aplicaciones de post análisis que brindan los paquetes de dinámica molecular. Una herramienta de estas características es de gran ayuda en el estudio de los datos obtenidos permitiendo al usuario proponer el análisis o representación de los mismos que considere necesarios. Para este trabajo, como ejemplo, se tomaron datos generados por el programa Gromacs y fueron incorporados a una base de datos desarrollada en un entorno web. Se seleccionaron simulaciones de una bicapa lipídica expuesta a un campo eléctrico por el gran costo computacional que presenta de modo de generar una aplicación que pueda ser capaz de analizar datos independientemente de la demanda que éstos requieran. El sitio web se desarrolló con el framework Django, el cual permite utilizar Python, mientras que la base de datos se implementó en PostgreSQL. Se obtuvo una aplicación web que permite cargar datos de una trayectoria y generar un análisis estadístico, así como gráficos y representaciones espaciales. Se propone generar modelos 3D que permitan estimar superficie o volumen de la selección de átomos que el usuario considere necesarios."
Nanobioingeniería: historia y futuro
(2015) Risk, Marcelo
"Las aplicaciones de la nanotecnología desde la ingeniería a los ámbitos de la biología y la medicina constituyen la nanobioingeniería. Entonces la nanobioingeniería se puede describir como un área de trabajo multidisciplinaria, donde convergen las ciencias básicas como biología, matemática, química y física, con la medicina, la electrónica, la mecánica, informática y los aspectos éticos y legales."
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.
Two-dimensional posture evaluation in Parkinson’s disease: effect of loads on the spinal angle during gait
(2016) Celoria, Paula; Nanni, Federico; Pastore, Flavia Carina; Pulenta, Sebastián; Tajerian, Matías Nazareth; Pantazis, Lucio; Moscoso-Vásquez, Marcela; Cerquetti, Daniel; Merello, Marcelo; Risk, Marcelo
"Parkinson’s Disease patients present diminished coordination caused by neural degeneration. This leads to large motor difficulties during gait such as balance loss and pronounced forward inclination of the upper body. This work assessed the spinal sagittal plane angle alterations in two groups: six parkinsonian patients and six control healthy subjects. This parameter was analyzed during gait under three conditions: without external loads and with external loads applied either on the chest or on the lower back area. Results were statistically compared by means of t-test of paired samples in both groups. For patients, a significant effect was found when loads were applied on the chest. On the other hand, healthy subjects showed no significant differences in either case."
Time Domain Estimation of Arterial Parameters using the Windkessel Model and the Monte Carlo Method
(IOP Publishing Ltd, 2016) Gostuski, Vladimir; Pastore, Ignacio; Rodriguez Palacios, Gaspar; Vaca Diez, Gustavo; Moscoso-Vasquez, Marcela; Risk, Marcelo
"Numerous parameter estimation techniques exist for characterizing the arterial system using electrical circuit analogs. However, they are often limited by their requirements and usually high computational burdain. Therefore, a new method for estimating arterial parameters based on Monte Carlo simulation is proposed. A three element Windkessel model was used to represent the arterial system. The approach was to reduce the error between the calculated and physiological aortic pressure by randomly generating arterial parameter values, while keeping constant the arterial resistance. This last value was obtained for each subject using the arterial flow, and was a necessary consideration in order to obtain a unique set of values for the arterial compliance and peripheral resistance. The estimation technique was applied to in vivo data containing steady beats in mongrel dogs, and it reliably estimated Windkessel arterial parameters. Further, this method appears to be computationally efficient for on-line time-domain estimation of these parameters."
Desarrollo de una interfaz DICOM para la integración de una familia de monitores de mecánica respiratoria a una historia clínica electrónica
(2017) Gostuski, Vladimir Rista; Madorno, Matías
"La interoperabilidad sintáctica en DICOM tiene dos componentes: el formato que debe llevar la información (imágenes, formas de onda, etc.) y la comunicación entre aplicaciones. El alcance de este proyecto está limitado a desarrollar el primer componente, tomando los archivos generados por los equipos FluxMed y convirtiéndolos a formato DICOM. Desarrollar esta herramienta como una aplicación que se ejecuta desde la línea de comando permite integrarla a otros software que ejecuten este proceso, dándole versatilidad en la integración con otros dispositivos."
Mi mundo físico en la nube
(2017) Müller, Malena; Máspero, Martina; Pierdominici, Matías
"El crecimiento crecimiento exponencial de IOT (Internet de las cosas) ha dado lugar a un gran gran número de herramientas que facilitan el desarrollo de aplicaciones. En este este trabajo se presenta una de estas estas: Node -RED."
Is needle biopsy clinically useful in preoperative grading of central chondrosarcoma of the pelvis and long bones?
(2017) Roitman, Pablo D.; Farfalli, Germán L.; Ayerza, Miguel A.; Múscolo, D. Luis; Milano, Federico E.; Aponte-Tinao, Luis A.
"Central chondrosarcoma of bone is graded on a scale of 1 to 3 according to histological criteria. Clinically, these tumors can be divided into low-grade (Grade 1) and high-grade (Grade 2, Grade 3, and dedifferentiated) chondrosarcomas. Although en bloc resection has been the most widely used treatment, it has become generally accepted that in selected patients with low-grade chondrosarcomas of long bones, curettage is safe and effective. This approach requires an accurate preoperative estimation of grade to avoid under- or overtreatment, but prior reports have indicated that both imaging and biopsy do not always give an accurate prediction of grade."
Redes neuronales en bioingeniería
(2017) Celoria, Paula; Nanni, Federico; Pulenta, Sebastián; Tajerian, Matías Nazareth
"Dos proyectos son presentados. Por un lado, la implementación de red de Hopfield competitiva con mecanismo de aprendizaje winner-takes-all (WTA) para segmentación de imágenes biomédicas e identificación de tejidos. Por otro lado, la aplicación de análisis de componentes principales (PCA) y una red neuronal de dos capas para clasificación de latidos en una señal de electrocardiograma (ECG)."
Desarrollo de una herramienta de cuantificación regional basada en la mecánica respiratoria y la tomografía por impedancia eléctrica
(2017) Celoria, Paula; Nanni, Federico; Madorno, Matías
"La combinación de los parámetros globales de la mecánica respiratoria con la sincronización de las señales de ventilación mecánica y de tomografía por impedancia (TIE), se puede utilizar para hallar información regional. El objetivo de este proyecto apunta al desarrollo de una herramienta basada en la TIE para calcular la heterogeneidad de las complacencias regionales del sistema respiratorio."
Diseño integral de un test basado en secuenciación dirigida para guiar el manejo terapéutico del cáncer colorrectal
(2017) Ganiewich, Daiana; Llera, Andrea; Podhajcer, Osvaldo
"El advenimiento de la secuenciación masiva (NGS) ha hecho posible interrogar el genoma en búsqueda de variantes que afecten el desarrollo y el tratamiento del cáncer. El cáncer es una enfermedad que se origina en la acumulación de mutaciones en células, de las cuales algunas son responsables del cambio fenotípico que permite al tumor crecer desmedidamente. En este proyecto nos propusimos diseñar un panel de secuenciación dirigido para detectar mutaciones que son fundamentales para establecer la conducta terapéutica más adecuada en cáncer colorrectal. Para ello integramos en un mismo test las mutaciones de tipo SNP o indels que son más informativas para clasificar al paciente en función de su probable evolución (mutaciones clasificatorias); las mutaciones de ADN de tipo SNP o indels más informativas para determinar qué fármacos serían los de elección para una terapia dirigida en cáncer colorrectal; y los polimorfismos de DPYD de línea germinal que afectan el metabolismo del 5-FU, principal quimioterápico utilizado en cáncer colorrectal. Se analizan todos los pasos requeridos para un servicio de estas características, desde la mejor combinación de marcadores genómicos buscados, hasta su análisis e interpretación así como también un estudio preliminar de costo-efectividad para verificar su factibilidad económica a priori. Desarrollar esta herramienta como una aplicación que se ejecuta desde la línea de comando permite integrarla a otros software que ejecuten este proceso, dándole versatilidad en la integración con otros dispositivos."
User-centered design improves the usability of drug-drug interaction alerts: experimental comparison of interfaces
(2017) Luna, Daniel; Rizzato Lede, Daniel; Otero, Carlos; Risk, Marcelo; González Bernaldo de Quirós, Fernán
"Clinical Decision Support Systems can alert health professionals about drug interactions when they prescribe medications. The Hospital Italiano de Buenos Aires in Argentina developed an electronic health record with drug-drug interaction alerts, using traditional software engineering techniques and requirements. Despite enhancing the drug-drug interaction knowledge database, the alert override rate of this system was very high. We redesigned the alert system using user-centered design (UCD) and participatory design techniques to enhance the drug-drug interaction alert interface. This paper describes the methodology of our UCD. We used crossover method with realistic, clinical vignettes to compare usability of the standard and new software versions in terms of efficiency, effectiveness, and user satisfaction. Our study showed that, compared to the traditional alert system, the UCD alert system was more efficient (alerts faster resolution), more effective (tasks completed with fewer errors), and more satisfying. These results indicate that UCD techniques that follow ISO 9241-210 can generate more usable alerts than traditional design."
Sistema de soporte a la decisión clínica para evaluación cuantitativa de riesgo de cáncer de mama
(2017) Tajerian, Matías Nazareth; Otero, Carlos; Rubin, Luciana
"El cáncer es la segunda causa de muerte en el mundo, siendo responsable de 1 de cada 6 muertes. En particular, el cáncer de mama es el más frecuente entre las mujeres y es el de mayor incidencia y mortalidad en Argentina. Es sabido que una detección temprana es crucial para el tratamiento de la enfermedad. En este sentido, la evaluación de riesgo es una herramienta de gran utilidad. Este proyecto se secciona en dos partes. En la primera se estudian cuatro modelos de evaluación de riesgo de cáncer de mama: los modelos de Gail, Claus, BRCAPRO y Tyrer-Cuzick. Se analizan sus métodos, factores de riesgo, limitaciones, entre otros aspectos. Finalmente, se procede a seleccionar uno de ellos para su implementación. La segunda parte consta del desarrollo de un sistema de soporte a la decisión clínica para evaluación cuantitativa de riesgo. En ésta se incorpora el modelo seleccionado, y se lleva a cabo un software para realizar el cálculo de riesgo, a partir del método en cascada. El trabajo realizado bajo la dirección de profesionales del Hospital Italiano de Buenos Aires, tiene una concreta proyección para ser aplicado en la historia clínica electrónica, con el objetivo de asistir a los profesionales de salud de atención primaria para la detección de pacientes de alto riesgo."
Desarrollo de una nueva técnica para la microfabricación de dispositivos microfluidícos basados en el fenómeno dielectroforético
(2017) Pastore Benaim, Ignacio; Morales, Mercedes Consuelo
"En este trabajo se propone una nueva técnica de microfabricación para dispositivos DEP. La misma se basa en la técnica de \toner-transfer" utilizada para construir circuitos impresos (PCB). Las plataformas microfluidícas basadas en PCB (\Lab-on-a-PCB") aprovechan tecnología ampliamente utilizada en la microelectrónica permitiendo el escalado en la producción. Además ofrecen una solución directa a uno de los desafíos más importantes que presenta la microfluidíca: la integración entre circuitos electrónicos y redes microfluidícas."
What is the expected learning curve in computer-assisted navigation for bone tumor resection?
(2017) Farfalli, Germán L.; Albergo, José I.; Ritacco, Lucas E.; Ayerza, Miguel A.; Milano, Federico E.; Aponte-Tinao, Luis A.
"Background Computer navigation during surgery can help oncologic surgeons perform more accurate resections. However, some navigation studies suggest that this tool may result in unique intraoperative problems and increased surgical time. The degree to which these problems might diminish with experience–the learning curve–has not, to our knowledge, been evaluated for navigation-assisted tumor resections. Questions/purposes (1) What intraoperative technical problems were observed during the first 2 years using navigation? (2) What was the mean time for navigation procedures and the time improvement during the learning curve? (3) Have there been any differences in the accuracy of the registration technique that occurred over time? (4) Did navigation achieve the goal of achieving a wide bone margin? Methods All patients who underwent preoperative virtual planning for tumor bone resections and operated on with navigation assistance from 2010 to 2012 were prospectively collected. Two surgeons (GLF, LAA-T) performed the intraoperative navigation assistance. Both surgeons had more than 5 years of experience in orthopaedic oncology with more than 60 oncology cases per year per surgeon. This study includes from the very first patients performed with navigation. Although they did not take any formal training in orthopaedic oncology navigation, both surgeons were trained in navigation for knee prostheses. Between 2010 and 2012, we performed 124 bone tumor resections; of these, 78 (63%) cases were resected using intraoperative navigation assistance. During this period, our general indications for use of navigation included pelvic and sacral tumors and those tumors that were reconstructed with massive bone allografts to obtain precise matching of the host and allograft osteotomies. Seventy-eight patients treated with this technology were included in the study. Technical problems (crashes) and time for the navigation procedure were reported after surgery. Accuracy of the registration technique was defined and the surgical margins of the removed specimen were determined by an experienced bone pathologist after the surgical procedure as intralesional, marginal, or wide margins. To obtain these data, we performed a chart review and review of operative notes. Results In four patients (of 78 [5%]), the navigation was not completed as a result of technical problems; all occurred during the first 20 cases of the utilization of this technology. The mean time for navigation procedures during the operation was 31 minutes (range, 11–61 minutes), and the early navigations took more time (the regression analysis shielded R2 = 0.35 with p\0.001). The median registration error was 0.6 mm (range, 0.3–1.1 mm). Registration did not improve over time (the regression analysis slope estimate is 0.014, with R2 = 0.026 and p = 0.15). Histological examinations of all specimens showed a wide bone tumor margin in all patients. However, soft tissue margins were wide in 58 cases and marginal in 20. Conclusions We conclude that navigation may be useful in achieving negative bony margins, but we cannot state that it is more effective than other means for achieving this goal. Technical difficulty precluded the use of navigation in 5% of cases in this series. Navigation time decreased with more experience in the procedure but with the numbers available, we did not improve the registration error over time. Given these observations and the increased time and expense of using navigation, larger studies are needed to substantiate the value of this technology for routine use. Level of Evidence Level IV, therapeutic study."
Impact of participatory design for drug-drug interaction alerts: a comparison study between two interfaces
(2017) Luna, Daniel; Otero, Carlos; Risk, Marcelo; Stanziola, Enrique; González Bernaldo de Quirós, Fernán
"Decision support systems for alert drug-drug interactions have been shown as valid strategy to reduce medical error. Even so the use of these systems has not been as expected, probably due to the lack of a suitable design. This study compares two interfaces, one of them developed using participatory design techniques (based on user centered design processes). This work showed that the use of these techniques improves satisfaction, effectiveness and efficiency in an alert system for drug-drug interactions, a fact that was evident in specific situations such as the decrease of errors to meet the specified task, the time, the workload optimization and users overall satisfaction with the system."
Creación de un modelo de gestión de tecnología médica basado en matrices de riesgos
(2017) Pastore, Flavia Carina; Mouriño, Bárbara
"El objetivo principal del presente trabajo fue crear un modelo simple e intuitivo, basado en matrices de riesgos, que ofrezca las herramientas necesarias para guiar la decisión de la renovación de equipamiento médico, mediante el ingreso de ciertas características del equipo; y que además permita identificar las acciones requeridas para efectuar los cambios necesarios en la Institución, previos a una renovación."
Classification of normal and pre-ictal EEG signals using permutation entropies and a generalized linear model as a classifier
(2017-02) Redelico, Francisco; Traversaro Varela, Francisco; García, María del Carmen; Silva, Walter; Rosso, Osvaldo A.; Risk, Marcelo
"In this contribution, a comparison between different permutation entropies as classifiers of electroencephalogram (EEG) records corresponding to normal and pre-ictal states is made. A discrete probability distribution function derived from symbolization techniques applied to the EEG signal is used to calculate the Tsallis entropy, Shannon Entropy, Renyi Entropy, and Min Entropy, and they are used separately as the only independent variable in a logistic regression model in order to evaluate its capacity as a classification variable in a inferential manner. The area under the Receiver Operating Characteristic (ROC) curve, along with the accuracy, sensitivity, and specificity are used to compare the models. All the permutation entropies are excellent classifiers, with an accuracy greater than 94.5% in every case, and a sensitivity greater than 97%. Accounting for the amplitude in the symbolization technique retains more information of the signal than its counterparts, and it could be a good candidate for automatic classification of EEG signals."
In vitro comparative study between conventional and computer-assisted surgery methods for planning and resection of bone sarcomas
(2017-08) Ritacco, Lucas E.; Aponte-Tinao, Luis A.; Múscolo, D. Luis; Ayerza, Miguel A.; Albergo, José I.; Farfalli, Germán L.; Risk, Marcelo; González Bernaldo de Quirós, Fernán; Milano, Federico E.
"This poster aims to achieve an “in vitro” comparative study between three methods: 2D digital images planning and execution without navigation (freehand with ruler and caliper), 3D planning and execution without navigation (freehand with ruler and caliper) and 3D planning and execution guided with navigation. 3D planning and navigated procedures potentially improve sarcoma resection."
Lipid electropore stabilization
(2017-08) Fernández, María Laura; Risk, Marcelo
"The stabilization of pores can be studied by different approaches such as simulations in silico or experimental procedures in vivo or in vitro. The energy to open a pore in a lipid membrane can be delivered by different external stimuli. To disrupt the membrane and initiate the pore opening, this energy has to reach a threshold. Then, once the pore is open, the external stimulus can be modulated to maintain the pore stable in time. This chapter first describes the basics of electropermeabilization, a process also called electroporation, and the basics of molecular dynamics in electropermeabilization. The chapter then describes in detail the molecular changes that lead to the pore opening and evolution by molecular dynamics. The chapter focuses on molecular dynamics because this technique allows the study of pore stabilization at molecular level, the interpretation of the lipid and water molecule rearrangements that are behind this phenomenon, and the visualization of the pore at the scale of size and time, in the order of nanometers and nanoseconds, respectively. Finally, the chapter also describes other approaches where pores remain open or the permeabilized state remains stable for a period of time, such as continuum modeling, experiments in planar membranes, and experiments in cells. The objective of this selection is to relate the results obtained by molecular dynamics with those obtained experimentally, or by other types of modeling, aiming to connect the mechanisms of pore stabilization by molecular dynamics at different scales."

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