Hyperspectral camera as a compact payload architecture for remote sensing applications.

Monitoring and observation over the surface of the Earth have been a matter of global interest. In this path, recent efforts aim to develop a spatial mission to perform remote sensing applications. Mainly, CubeSat nanosatellites have emerged as a standard for developing low-weight and small-sized instruments. In terms of payloads, state-of-the-art optical systems for CubeSats are expensive and designed to work in general use cases. To overcome these limitations, this paper presents a 1.4 U compact optical system to acquire spectral images from a CubeSat standard satellite at the height of 550 km. To validate the proposed architecture, optical simulations using ray tracing simulation software are presented. Because the performance of computer vision tasks is highly related to data quality, we compared the optical system in terms of the classification performance on a real remote sensing application. The performances of the optical characterization and land cover classification show that the proposed optical system achieves a compact instrument, operating at a spectral range from 450 nm to 900 nm discretized on 35 spectral bands. The optical system has an overall f-number of 3.41 with a ground sampling distance of 52.8 m and a swath of 40 km. Additionally, the design parameters for each optical element are publicly available for validation, repeatability, and reproducibility of the results.

Calibration reinforcement regularizations for optimized snapshot spectral imaging.

Optical coding is a fundamental tool in snapshot computational spectral imaging for capturing encoded scenes that are then decoded by solving an inverse problem. Optical encoding design is crucial, as it determines the invertibility properties of the system sensing matrix. To ensure a realistic design, the optical mathematical forward model must match the physical sensing. However, stochastic variations related to non-ideal characteristics of the implementation exist; therefore, these variables are not known a priori and have to be calibrated in the laboratory setup. Thus, the optical encoding design leads to suboptimal performance in practice, even if an exhaustive calibration process is carried out. This work proposes an algorithm to speed up the reconstruction process in a snapshot computational spectral imaging, in which theoretically optimized coding design is distorted by the implementation process. Specifically, two regularizers are proposed that perform the gradient algorithm iterations of the distorted calibrated system in the direction of the originally, theoretically optimized system. We illustrate the benefits of the reinforcement regularizers for several state-of-the-art recovery algorithms. For a given lower bound performance, the algorithm converges in fewer iterations due to the effect of the regularizers. Simulation results show an improvement of up to 2.5 dB of peak signal-to-noise ratio (PSNR) when fixing the number of iterations. Furthermore, the required number of iterations reduces up to 50% when the proposed regularizers are included to obtain a desired performance quality. Finally, the effectiveness of the proposed reinforcement regularizations was evaluated in a test-bed implementation, where a better spectral reconstruction was evidenced when compared with a non-regularized system's reconstruction.

C-3SPCD: coded aperture similarity constrained design for spatio-spectral classification of single-pixel measurements.

In recent years, compressive spectral imaging (CSI) has emerged as a new acquisition technique that acquires coded projections of the spectral scene, reducing considerably storage and transmission costs. Among several CSI devices, the single-pixel camera (SPC) architecture excels due to its low implementation cost when acquiring a large number of spectral bands. Although CSI allows efficient sampling, a complete reconstruction of the underlying scene is needed to perform any processing task, which involves solving a computationally expensive optimization problem. In this paper, we propose a fast method to classify the underlying spectral image by directly using compressed SPC measurements, avoiding reconstruction. In particular, the proposed method acquires an RGB image of the scene as side information to design the SPC coding patterns. Our design approach allows incorporating the similarity information of neighboring pixels from the RGB image into compressed measurements. After acquiring the compressed measurements with our designed coding patterns, we extract features of the scene to perform classification without reconstruction. After simulations, we obtained an overall accuracy of 95.41% and 97.72% for the Pavia University and Salinas spectral images, respectively. Furthermore, we tested our approach in the laboratory and classified our own dataset, which has four different materials: flowers, sand, grass, and dry leaves, with an overall accuracy of 94.66%.

Perioperative use of levosimendan in patients undergoing cardiac surgery: systematic review and meta-analysis / Uso perioperatorio de levosimendán en pacientes sometidos a cirugía cardiaca: revisión sistemática de la literatura y metaanálisis

Abstract Introduction: Patients undergoing cardiac surgery frequently develop low cardiac output syndrome (LCOS). Multiple interventions including levosimendan have been used in the prevention and treatment of LCOS. Preliminary studies reported lower mortality respect to placebo or other inotropes, however, recently, 3 clinical trials found no benefit against this outcome. Objective: Our objective was to evaluate the evidence of levosimendan on mortality and secondary outcomes in patients undergoing cardiac surgery, and to determine the sources of heterogeneity. Methods: We conducted a systematic review and meta-analysis of the clinical trials that evaluated the efficacy of levosimendan in patients undergoing cardiac surgery. We obtained the odds ratio (OR) of mortality and other outcomes such as kidney injury with dialysis requirement and LCOS, using fixed and random effects models. The risk of bias was assessed and the sources of heterogeneity were explored. Results: Of 47 studies identified, 14 studies were selected (n=2752). Regarding the mortality outcome and use of levosimendan, only a decrease was found in the studies of low quality (OR 0,30; CI 95%, 0,18 to 0,51). While high-quality studies, there was no protective effect (OR 0.99,95% CI 0.70-1.40) with an I2 = 0%. The quality of the studies and ejection fraction were the main sources of heterogeneity. Conclusion: In high-quality studies, the use of levosimendan in patients undergoing cardiovascular surgery has no effect on 30-day mortality. There was a protective effect on postoperative renal failure with dialysis.

Resumen Introducción: Los pacientes llevados a cirugía cardiaca tienen riesgo de desarrollar síndrome de bajo gasto cardiaco posoperatorio (SBGC). Estudios previos han encontrado una menor mortalidad con levosimendán respecto a placebo u otros inotrópicos; sin embargo, tres experimentos clínicos no encontraron beneficio frente a este desenlace. Objetivo: Evaluar la evidencia del levosimendán sobre la mortalidad y los desenlaces secundarios en pacientes sometidos a cirugía cardiaca, y determinar las fuentes de heterogeneidad. Métodos: Mediante una revisión sistemática y metaanálisis de los experimentos clínicos que evaluaron la eficacia del levosimendán en los pacientes llevados a cirugía cardiaca, se evaluó la eficacia en la mortalidad y en otros desenlaces, como lesión renal y SBGC, utilizando los modelos de efectos fijos y aleatorios. Resultados: De 47 estudios identificados, fueron seleccionados 14 (n = 2752). Respecto al desenlace de mortalidad y el uso de levosimendán solo se encontró una disminución en los estudios de baja calidad (OR 0.30; IC 95%, 0.18-0.51), mientras que para los de alta calidad no hubo efecto protector (OR 0.99; IC 95%, 0.70-1.40) con un I2=0%. La calidad de los estudios y la fracción de eyección fueron las principales fuentes de heterogeneidad. Conclusión: el uso del levosimendán en los pacientes llevados a cirugía cardiovascular no tiene efectos sobre la mortalidad a 30 días en los estudios de alta calidad. Hubo efecto protector sobre la falla renal postoperatoria con necesidad de diálisis.

Multi-Resolution Compressive Spectral Imaging Reconstruction from Single Pixel Measurements.

Massive amounts of data in spectral imagery increase acquisition, storing and processing costs. Compressive spectral imaging (CSI) methods allow the reconstruction of spatial and spectral information from a small set of random projections. The single pixel camera is a low cost optical architecture which enables the compressive acquisition of spectral images. Traditional CSI reconstruction methods obtain a sparse approximation of the underlying spatial and spectral information, however the complexity of these algorithms increases in proportion to the dimensionality of the data. This work proposes a multiresolution (MR) CSI reconstruction approach from single pixel camera measurements that exploits spectral similarities between pixels to group them in super-pixels such that the total number of unknowns in the inverse problem is reduced. Specifically, two different types of super-pixels are considered: rectangular and irregular structures. Simulation and experimental results show that the proposed MR scheme improves reconstruction quality in up to 6dB of PSNR and reconstruction time in up to 90% with respect to the traditional full resolution reconstructions.

Measurements of the nonlinear refractive index in scattering media using the Scattered Light Imaging Method--SLIM.

The Scattered Light Imaging Method (SLIM) was applied to measure the nonlinear refractive index of scattering media. The measurements are based on the analysis of the side-view images of the laser beam propagating inside highly scattering liquid suspensions. Proof-of-principle experiments were performed with colloids containing silica nanoparticles that behave as light scatterers. The technique allows measurements with lasers operating with arbitrary repetition rate as well as in the single-shot regime. The new method shows advantages and complementarity with respect to the Z-scan technique which is not appropriate to characterize scattering media.

Anatomía de la vía aérea para el broncoscopista. Una aproximación a la anestesia / Airway anatomy for the bronchoscopist: An anesthesia approach

Introducción: El conocimiento y desarrollo de habilidades en el manejo de la vía aérea es una de las competencias importantes en la formación del anestesiólogo; el «saber¼ y el «saber hacer bien y rápido¼ son determinantes en algunas situaciones críticas a las que se puede enfrentar durante el manejo anestésico. La broncoscopia es un procedimiento útil tanto diagnóstico como terapéutico. El conocimiento de la técnica y de la anatomía de la vía aérea constituye el pilar de la broncoscopia, encontrando diferentes variaciones anatómicas y clasificaciones de la vía aérea. Objetivo: Describir la anatomía de la vía aérea a través de esquemas, evaluar variaciones anatómicas y conocer características propias del procedimiento. Metodología: Con las palabras clave «Bronchoscopy¼, «Anatomy¼, «Airway¼ y «Anesthesia¼ se realizó una revisión no sistemática en bases de datos (PUBMED/MEDLINE, Science Direct, OVID, SciELO). Resultados y conclusiones: La broncoscopia es un procedimiento útil en el plano quirúrgico y diagnóstico, siendo utilizado en distintos procedimientos. Las variaciones anatómicas de la vía aérea se presentan en un porcentaje pequeño de la población. Las clasificaciones anatómicas son diversas tanto anatómica como numéricamente; sin embargo, lo relevante es desarrollar una relación espacial. La broncoscopia es una técnica que va en desarrollo paralelo a otros avances de la tecnología biomédica, es un procedimiento del cual el anestesiólogo debe investigar más con el fin de generar mejores efectos en el campo de la anestesiología.

Introduction: Knowledge and development of skills in the management of the airway is one of important competencies in the training of the anesthesiologist, "knowledge" and "know how well and fast" are decisive in some critical situations during the anesthetic management. Bronchoscopy is a useful both diagnostic and therapeutic procedure. Knowledge of technique and the anatomy of the airway is the key of bronchoscopy, finding different anatomic variations and classifications of the airway. Objective: Describe the airway anatomy through diagrams, evaluate anatomic variations and characteristics of procedure. Methodology: With the keywords "Bronchoscopy" and "Anatomy", "Airway", "Anesthesia" held a non-systematic review databases (PUBMED/MEDLINE, OVID, Science Direct, SciELO). Results and conclusions: The bronchoscopy is a useful procedure in the surgical level and diagnosis, being used in various procedures. Airway anatomical variations occur in a small percentage of the population. Anatomical classifications are different both anatomic as numerically, but what is important is developing a spatial relation. Bronchoscopy is a technique that goes in parallel development of other advances in biomedical technology, is a procedure whereby the anesthesiologist should be investigated in order to generate better effects in the field of the anesthesiology.

Ability of the third-generation FloTrac/Vigileo software to track changes in cardiac output in cardiac surgery patients: a polar plot approach.

OBJECTIVE: To evaluate the ability of the third-generation (3.01) of FloTrac/Vigileo monitor (Edwards Lifesciences, Irvine, CA) to follow variations in cardiac output (∆CO) using the new polar plot approach. DESIGN: Prospective interventional study. SETTING: Single hospital university study. PARTICIPANTS: Twenty-five patients referred for cardiac surgery. INTERVENTIONS: CO was measured simultaneously by 3 to 5 bolus thermodilution (COtd measurements), using a pulmonary artery catheter and by arterial pulse contour analysis, using the FloTrac/Vigileo (COvi). Data were collected at eight time points: before incision, after sternotomy, before and after protamine sulfate infusion, at the start of sternal closure, at the end of surgery, on arrival to intensive care unit, and after a standardized volume expansion with 500 mL of hetastarch 6%. MEASUREMENTS AND MAIN RESULTS: One-hundred thirty-five pairs of CO data were collected; the mean bias of all CO measurements corrected for repeated measures was 0.2 L/min with limits of agreements of -3.3 L/min and +2.9 L/min. The percentage error was 66.5%. The polar plot analysis included 71 significant ∆CO and showed a mean polar angle of -3.4 degrees with 95% polar percentage error equivalent limits of -61 to 55; 69% of analysed data points fell within the 30-degree limits and provided a correct polar concordance rate. CONCLUSIONS: Third-generation FloTrac/Vigileo software still lacks the accuracy to reliably detect changes in cardiac output (∆CO) in cardiac surgery. Improvements to FloTrac/Vigileo CO algorithm and software still are needed in this particular setting.

Diferencia de iones fuertes (DIF): un acercamiento a la teoría de Stewart / Strong ion difference (SID): an approach to Stewart’s theory

El ión hidrógeno tiene la propiedad de interactuar de manera rápida con diferentes moléculas en el organismo, así como enzimas, receptores y la participación en reacciones bioquímicas y es el mismo organismo el encargado de regular su concentración en los diferentes compartimentos del cuerpo. Y es donde los trabajos desarrollados por Stewart han demostrado que la homeostasis del ión hidrógeno en los trastornos acido base no depende de si mismo y/o del intercambio con bicarbonato para tamponar el déficit o el exceso, sino que lo convierte en una variable dependiente de otros factores para su regulación en cada uno de los compartimentos, dándole importante validez a la presencia de acidos débiles, manteniendo la influencia del CO2 y resaltando la capacidad de los iones fuertes como principales determinantes en la concentración de H+ y de esta manera explica la causa en las variaciones del pH en el ser humano.

Tratamiento inmunosupresor combinado en la nefritis lúpica: reporte de un caso / Immunosuppressive treatment combined with lupic nephritis: report of a case

El tratamiento de la glomerulonefritis mesangiocapilar, una de las afectaciones más severas de la nefropatía lúpica, se basa en la combinación de esteroides e inmunosupresores. Los “bolos” de metilprednisolona junto a ciclofosfamida intravenosa, se han utilizado para la inducción de la remisión de la enfermedad con resultados eficaces, empleándose otros tipos de agentes en los casos refractarios a esta terapia. El presente caso trata de un paciente masculino 29 años de edad, con antecedentes patológicos personales de asma bronquial, antecedentes patológicos familiares: abuelo fallecido por lupus eritematoso sistémico (LES). Evolución clínica de 5 meses, con fatiga, caída del cabello, fiebre intermitente; tres semanas antes de su admisión presenta edema de miembros inferiores progresivo, oliguria, siendo ingresado por síndrome nefrótico. El laboratorio evidenció al menos cuatro criterios para LES, practicándose biopsia renal, que reveló una glomerulonefritis mesangioendotelial, clase IV, según la OMS estableciéndose su diagnóstico y tratamiento con corticoides e inicio con pulsos mensuales de ciclofosfamida debido a la severidad del cuadro, con mejoría parcial del mismo.

The treatment of mesangiocapillary glomerulonephritis, one of the most severe affectations of the lupic nephropathy, is based on the combination of steroids and immunosuppressors. The “Boluses” of methylprednisolone together with intravenuous cyclophosphamide, have been used for the induction remission of the illness with effective results, using other types of agent in the cases refractive to this therapy. The present case is about a 29-year old male patient with personal pathological antecedent of bronchial asthma, family pathological antecedent: grandfather died of Systemic Lupus erythematosus (SLE). Clinic development of 5 months, with fatigue, hair loss, intermittent fever; three weeks before admission he had progressive edema of inferior limbs, oliguria, he was admitted with nephrotic syndrome. The laboratory evidenced at least four criteria for SLE, by practicing renal biopsy, which revealed mesangiocapillary glomerulonephritis type IV, according to WHO, establishing its diagnosis and treatment with corticoid beginning with monthly pulse of cyclophosphamide due to the severity of the manifestations, obtaining, as a result partial improvement.

Dexmedetomidina para anestesia endovenosa en procedimientos vasculares / Dexmedetomidina for endovenosa anesthesia in procedures vasculares

La dexmedetomidina es un agonista alfa altamente selectivo, con propiedades anestesias analgésicas y simpaticolítica. Los efectos simpaticolíticos están manifestados por disminución de la tensión arterial TA, la frecuencia cardiaca FC, y la liberación de norepinefrina. Por su seguridad como agente sedante que no produce depresión respiratoria, ha sido aprobado su uso en cuidados intensivos desde 1999, pero recientemente se ha ampliado su uso en anestesia. Este medicamento tiene el potencial de atenuar los incrementos de TA y FC en el perioperatorio, además la dexmedetomidina tiene la facultad de disminuir los requerimientos de opiodes y agentes anestésicos inhalatorios como coadyudante durante la anestesia general...