Microwave Imaging for Brain Stroke Monitoring

The capability of microwaves to penetrate an object as interact differently with each of its elements, allows Microwave Imaging (MWI) technologies to be used in a myriad of fields and applications to "see-through" an object in a non-invasive approach. For instance, in the biomedical field, the scattered signals from cancer lesions, blood accumulation, and bio-tissues (all considered dielectric objects) contain the information required by imaging of the specific context. In the case of the open medical issue of brain stroke monitoring after onset, MWI provides clinicians with a complementary alternative to the well-establish imaging-based techniques of support of diagnosis and treatment follow-up. An example of a novel low-complexity-architecture MWI prototype with an optimized number of antennas and adequate positioning on a helmet is presented below. It exploits a differential imaging approach and provides 3D images of the stroke

Realistic Numerical Modelling for 3-D brain stroke monitoring

This paper aims to provide a realistic 3-D modelling framework of a real-world microwave imaging system for brain monitoring that mimics pre-assessment experimental clinical scenarios and lab setups. The model considers an anthropomorphic adult head with multiple tissues, a hemorrhagic brain stroke and a detailed prototype of a modular microwave antennas helmet. The set of antennas detect changes in the permittivity of biological tissues and then imaging reconstruction algorithms generates a 3-D representation of stroke using EM fields and scattering data generated by a full-wave numerical simulation. As results, it is presented a reconstruction of onset stroke in the white matter area of the brain using a TSVD algorithm and the born approximation for imaging

Multi-shot Calibration Technique for Microwave Imaging Systems

This paper proposes a novel “multi-shot” calibration technique that reduces imaging microwave reconstructions artifacts, compensating for uncontrolled variations during the measuring process and later propagated in the inversion. The calibration combines different consecutive sets of measured data with simulated ones in a post-processing stage, providing benefits without the need for additional experimental reference calibrations. The proposed scheme is tested experimentally in a non-trivial scenario. A microwave scanner images an early-stage hemorrhagic stroke in the left parietal lobe, applying a differential imaging algorithm based on the truncated singular value decomposition. Though, the proposed mechanisms can be used for other microwave imaging devices. The results reveal that the calibration procedure improves the quality of the retrieved images compared to the non-calibrated approach, cleaning the images and making the interpretation of imaged contrast variation easier

Hybrid imaging kernel calibration applied on microwave scanner for brain stroke monitoring

This paper validates a calibration procedure applied on a microwave imaging (MWI) kernel based on the combination of pre-computed simulated data and available S-parameters measurements. The assessed technique compensates for the image degradation caused by mild and non-modeled features of the imaging device, such as the unavoidable manufacturing discrepancies in the antenna array. The testing considers a synthetically mimicked experimental scenario of a hemorrhagic stroke condition and a realistic scanner prototype. This approach allows a thorough comparative assessment of the calibration effect on the electric field estimation used by the MWI algorithm, hardly achievable with measurements. The results show the capability of the calibration procedure to reduce the retrieved images’ distortions and artifacts compared to the non-calibrated approach, being an essential milestone toward its application in real-life scenarios

Solución de un modelo de arreglos fotovoltaicos serie-paralelo utilizando algoritmos de optimización global

Models of series-parallel (SP) photovoltaic (PV) arrays focus on the system of nonlinear equations that represents the array’s electrical behavior. The solution of the system of nonlinear equations can be posed as an optimization problem and solved with different methods; however, the models do not formulate the optimization problem and do not evaluate different optimization algorithms for its solution. This paper proposes a solution, using global optimization algorithms, of the mathematical model that describes the electrical behavior of a SP generator, operating under uniform and partial shading conditions. Such a model is constructed by dividing the generator into strings and representing each module in the string with the single-diode model. Consequently, for each string a system of nonlinear equations is build applying the Kirchhoff’s laws, where the unknowns are the modules’ voltages. The solution of the resulting nonlinear equation system is posed as an optimization problem, where the objective function is defined as the sum of the squared of each nonlinear equation. Minimum and maximum values of each voltage are defined from the datasheet information of the modules and bypass diodes. As a demonstrative example, we arbitrarily select two well-known algorithms to solve this problem: Genetic Algorithms and Particle Swarm Optimization. Simulation results show that both algorithms solve the optimization problem and allow the reproduction of the generator’s characteristic curves. Moreover, the results also indicate that the optimization problem is correctly defined, which opens the possibility explore other optimization algorithms to reduce the computation time.Los modelos de arreglos fotovoltaicos (FV) en serie-paralelo (SP) se enfocan en el sistema de ecuaciones no lineales que represental comportamiento eléctrico del arreglo. La solución del sitemas de ecuaciones se puede plantear como un problema de optimización y resolverse con diferentes métodos; sin embargo, los modelos no formulan el problema de optimización y no evaluan diferentes algoritmos de optimización para su solución. Este artículo propone una solución, utilizando algoritmos de optimización global, del modelo matemático que describe el comportamiento eléctrico de un generador fotovoltaico en serie-paralelo, que opera bajo condiciones uniformes y de sombreados parciales. Dicho modelo se construye dividiendo el generador en cadenas y representando cada módulo en la cadena con el modelo de diodo-único. En consecuencia, para cada cadena se construye un sistema de ecuaciones no lineales aplicando las leyes de Kirchhoff, en donde las incógnitas son los voltajes de los módulos. La solución del sistema de ecuaciones no lineales resultante se plantea como un problema de optimización, donde la función objetivo se define como la suma del cuadrado de cada ecuación no lineal. Los valores mínimos y máximos de cada voltaje se definen a partir de la información de la hoja de datos de los módulos y de los diodos de derivación. Como ejemplo demostrativo, se seleccionaron arbitrariamente dos algoritmos bien conocidos para resolver este problema: Algoritmos Genéticos y Optimización por Enjambre de Partículas. Los resultados de simulación muestran que los dos algoritmos ambos algoritmos resuelven el problema de optimización y permiten la reproducción de las curvas características del generador. Adicionalmente, los resultados también indican que el problema de optimización se definió correctamente, lo cual abre la posibilidad de explorar otros algoritmos de optimización para reducir el tiempo de cómputo

Solución de un modelo de arreglos fotovoltaicos serie-paralelo utilizando algoritmos de optimización global

Models of series-parallel (SP) photovoltaic (PV) arrays focus on the system of nonlinear equations that represents the array’s electrical behavior. The solution of the system of nonlinear equations can be posed as an optimization problem and solved with different methods; however, the models do not formulate the optimization problem and do not evaluate different optimization algorithms for its solution. This paper proposes a solution, using global optimization algorithms, of the mathematical model that describes the electrical behavior of a SP generator, operating under uniform and partial shading conditions. Such a model is constructed by dividing the generator into strings and representing each module in the string with the single-diode model. Consequently, for each string a system of nonlinear equations is build applying the Kirchhoff’s laws, where the unknowns are the modules’ voltages. The solution of the resulting nonlinear equation system is posed as an optimization problem, where the objective function is defined as the sum of the squared of each nonlinear equation. Minimum and maximum values of each voltage are defined from the datasheet information of the modules and bypass diodes. As a demonstrative example, we arbitrarily select two well-known algorithms to solve this problem: Genetic Algorithms and Particle Swarm Optimization. Simulation results show that both algorithms solve the optimization problem and allow the reproduction of the generator’s characteristic curves. Moreover, the results also indicate that the optimization problem is correctly defined, which opens the possibility explore other optimization algorithms to reduce the computation time.Los modelos de arreglos fotovoltaicos (FV) en serie-paralelo (SP) se enfocan en el sistema de ecuaciones no lineales que represental comportamiento eléctrico del arreglo. La solución del sitemas de ecuaciones se puede plantear como un problema de optimización y resolverse con diferentes métodos; sin embargo, los modelos no formulan el problema de optimización y no evaluan diferentes algoritmos de optimización para su solución. Este artículo propone una solución, utilizando algoritmos de optimización global, del modelo matemático que describe el comportamiento eléctrico de un generador fotovoltaico en serie-paralelo, que opera bajo condiciones uniformes y de sombreados parciales. Dicho modelo se construye dividiendo el generador en cadenas y representando cada módulo en la cadena con el modelo de diodo-único. En consecuencia, para cada cadena se construye un sistema de ecuaciones no lineales aplicando las leyes de Kirchhoff, en donde las incógnitas son los voltajes de los módulos. La solución del sistema de ecuaciones no lineales resultante se plantea como un problema de optimización, donde la función objetivo se define como la suma del cuadrado de cada ecuación no lineal. Los valores mínimos y máximos de cada voltaje se definen a partir de la información de la hoja de datos de los módulos y de los diodos de derivación. Como ejemplo demostrativo, se seleccionaron arbitrariamente dos algoritmos bien conocidos para resolver este problema: Algoritmos Genéticos y Optimización por Enjambre de Partículas. Los resultados de simulación muestran que los dos algoritmos ambos algoritmos resuelven el problema de optimización y permiten la reproducción de las curvas características del generador. Adicionalmente, los resultados también indican que el problema de optimización se definió correctamente, lo cual abre la posibilidad de explorar otros algoritmos de optimización para reducir el tiempo de cómputo

Brick Shaped Antenna Module for Microwave Brain Imaging Systems

In this letter, we describe and validate a microwave antenna designed for an imaging device for the diagnosis and monitoring of cerebrovascular pathologies. The antenna consists of a printed monopole immersed in a parallelepipedic block of semiflexible material with custom-permittivity, which allows to avoid the use of liquid coupling media and enables a simple array arrangement. The “brick” is built with a mixture of urethane rubber and graphite powder. The -10 dB frequency band of the antenna is 800 MHz-1.2 GHz, in agreement with the device requirements. The designed brick antenna is assessed in terms of power penetration, reflection, and transmission coefficients. To show the performance of the antenna in the relevant application scenario, an experiment has been carried out on an anthropomorphic head phantom, measuring the differential signals between healthy state and hemorrhagic stroke mimicking condition for different antennas positions

La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia. Departamento de Sucre y Bolívar

A lo largo del curso se ha trabajado de manera conjunta un tema que ha sido de gran relevancia e importancia en nuestro país como lo es la violencia armada, pero que a raíz de los diferentes contextos en los que estos se han desarrollado, se le ha dado por ende un abordaje diferente a cada uno de ellos. Es importante recalcar que la violencia ha sido hoy por hoy un recurrente en la vida de aquellas familias que han sido sacadas o vulneradas de sus comunidades, pueblos, veredas, municipios y demás, y que por ende han hecho parte del olvido de las generaciones que han estado inmiscuidos como entes territoriales, gubernamentales y nacionales que han estado a cargo de las políticas públicas quienes son los encargados de darle un mejor manejo a esta problemática, cabe destacar que la violencia no es sólo física, hay violencia social, económica, familiar, sexual, entre otras. En este apartado se evidencia el caso de Camilo y el caso de Peñas Coloradas, relatos de vidas que dan cuentan de la poca colaboración o ayuda del estado, vulneración de derechos, falta de recursos, olvido, desalojos de tierras, víctimas de la violencia, perdida de propósito de vida y bienestar psicológico, dolor, desesperanza, pero sobre todo sobrevivientes de una situación que marca su vida por un hecho traumático. Los relatos de violencias le permiten al psicólogo realizar un abordaje psicosocial, estableciendo estrategias desde, la narrativa, lo subjetivo, lo simbólico y la memoria herramientas pertinentes para mejorar hechos traumáticos.Throughout the course, a topic that has been of great relevance and importance in our country, such as armed violence, has been worked on jointly, but as a result of the different contexts in which these have been developed, it has been therefore given a different approach to each of them. It is important to emphasize that violence has today been a recurring feature in the lives of those families that have been removed or violated from their communities, towns, villages, municipalities, and others, and that therefore have been part of the oblivion of the generations that They have been involved as territorial entities, governments and nationals that have been in charge of public policies who are in charge of giving better management to this problem, it should be noted that violence is not only physical, there is social, economic, family violence, sex, among others. In this section we will work with a particular case and it is the case of Camilo and the case of Peñas Coloradas, which was established by its own inhabitants without receiving collaboration or help from the state, but which unfortunately was condemned and censored for collaborating in a way directly and indirectly with a group outside the law, in this case (La Guerrilla), they were also told to market the drug and take advantage of it for their economic development. The stories of violence allow the psychologist to carry out a psychosocial approach, present strategies from the narrative, the subjective, the symbolic and memory, relevant tools to improve traumatic events

Development of a remote sensing and control system for greenhouse applications

Real-time monitoring provides reliable, timely information of crop and soil status, important in taking decisions for crop production improvement. This work presents a real-time monitoring and control system for climatological variables in greenhouse. The system has wireless communication capabilities, which allow it to cover extensive surfaces in real-time, without extra resources. The system implementation is based on the micro controllers “PIC18F4550” and “DSPIC 30F5011”, user interface was programmed under LINUX. The proposed system performance was compared with commercial Data Loggers, readings present a linear adjustment with R2=0.9656

Development of a remote sensing and control system for greenhouse applications

Real-time monitoring provides reliable, timely information of crop and soil status, important in taking decisions for crop production improvement. This work presents a real-time monitoring and control system for climatological variables in greenhouse. The system has wireless communication capabilities, which allow it to cover extensive surfaces in real-time, without extra resources. The system implementation is based on the micro controllers “PIC18F4550” and “DSPIC 30F5011”, user interface was programmed under LINUX. The proposed system performance was compared with commercial Data Loggers, readings present a linear adjustment with R2=0.9656