Métodos de estimación de dosis a pacientes en tomografía computarizada

Este trabajo tiene por finalidad la estimación de la dosis que se reciben en las exploraciones mediante Tomografía de Rayos X. Para ello se han utilizado los datos, software y metodología proporcionados por el Servicio de Protección Radiológica del Hospital Universitario Río Hortega de Valladolid (HURH) que ha supervisado los resultados obtenidos en las exploraciones más frecuentes llevadas a cabo en estos equipos; Exploraciones de cabeza, tórax y abdomen. Además presenta un resumen de las pruebas de calidad que periódicamente realizan los radiofísicos para verificar el correcto funcionamiento del equipo.Grado en Físic

Extension of PAR Models under Local All-Sky Conditions to Different Climatic Zones

Four models for predicting Photosynthetically Active Radiation (PAR) were obtained through MultiLinear Regression (MLR) and an Artificial Neural Network (ANN) based on 10 meteorological indices previously selected from a feature selection algorithm. One model was developed for all sky conditions and the other three for clear, partial, and overcast skies, using a sky classification based on the clearness index (kt). The experimental data were recorded in Burgos (Spain) at ten-minute intervals over 23 months between 2019 and 2021. Fits above 0.97 and Root Mean Square Error (RMSE) values below 7.5% were observed. The models developed for clear and overcast sky conditions yielded better results. Application of the models to the seven experimental ground stations that constitute the Surface Radiation Budget Network (SURFRAD) located in different Köppen climatic zones of the USA yielded fitted values higher than 0.98 and RMSE values less than 11% in all cases regardless of the sky type.This research was funded by the Spanish Ministry of Science and Innovation, grant number RTI2018-098900-B-I00, and Consejería de Empleo e Industria, Junta de Castilla y León, grant number INVESTUN/19/BU-0004

A Low-Cost Luxometer Benchmark for Solar Illuminance Measurement System Based on the Internet of Things

Natural illumination has an important place in home automation applications. Among other advantages, it contributes to better visual health, energy savings, and lower CO2 emissions. Therefore, it is important to measure illuminance in the most accurate and cost-effective way. This work compares several low-cost commercial sensors (VEML 7700, TSL2591, and OPT3001) with a professional one (ML-020S-O), all of them installed outdoors. In addition, a platform based on the Internet of Things technology was designed and deployed as a centralized point of data collection and processing. Summer months have been chosen for the comparison. This is the most adverse situation for low-cost sensors since they are designed for indoor use, and their operating range is lower than the maximum reached by sunlight. The solar illuminance was recorded every minute. As expected, the obtained bias depends on the solar height. This can reach 60% in the worst circumstances, although most of the time, its value stays below 40%. The positive side lies in the good precision of the recordings. This systematic deviation makes it susceptible to mathematical correction. Therefore, the incorporation of more sensors and data that can help the global improvement of the precision and accuracy of this low-cost system is left as a future line of improvement.The authors gratefully acknowledge the financial support provided by the Spanish Ministry of Science & Innovation under the I+D+i state program “Challenges Research Projects” (RTI2018-098900-B-I00) and the Regional Government of Castilla y León (IN-VESTUN/19/BU/004 and INVESTUN/22/BU/0001). Diego Granados López also thankfully acknowledges the financial support from the Junta de Castilla-León (ORDEN EDU/556/2019)

Seasonal caracterization of CIE standard sky types above Burgos, northwestern Spain

Outdoor daylight conditions in Burgos, Spain, are studied throughout a full year. The CIE standard sky type is selected in accordance with the lowest RMSD (Root Mean Square Deviation) following the comparison of both the theoretical and the experimental luminance distributions in the sky hemisphere. The original criterion to determine the type of sky, the SSLD (the Standard Sky Luminance Distribution), is difficult to apply in certain places and at times when the solar elevation is higher than 35°. In consequence, two alternative procedures are used and compared in this study: the Tregenza method and the Normalization Rate (NR) introduced by Littlefair. The selection was taken from luminance distribution data of 145 patches of the sky hemisphere recorded between June 2016 and May 2017. The most frequent sky type observed in Burgos was V.5. (cloudless polluted with a broad solar corona), with a frequency of occurrence close to 20%. Notwithstanding that observation, the group of clear skies exhibited a higher frequency (in almost 50% of the cases under study, using both methods). The skies above Burgos were of an overcast sky type in less than 25% of cases, a situation with a higher likelihood in winter and in autumn, while in spring and summer the skies tended to be clear and cloud free. Both of the methodologies showed similar results in percentage terms and in confusion matrixes with almost insignificant differences when compared on a monthly, a seasonal, and an annual basis. Nevertheless, some mismatches were located in the highest solar elevation values.Regional Government of Castilla y León (Ref. BU034U16), under European Regional Development Fund, and the Spanish Ministry of Economy, Industry and Competitiveness, under the I+D+i State Programme Challenges for the Society (Ref. ENE-2014-54601-R

Benchmarking of meteorological indices for sky cloudiness classification

Sky classification is a complex problem, due in part to such abstract conceptual definitions as clear, intermediate, and overcast, as well as other intermediate ranges. The CIE (Commission Internationale de L’Éclairage) Standard classification offers a solution to this problem, although its application requires data on the luminance distribution of the whole sky that are less commonly available. A benchmarking and classification system of ten meteorological indices is introduced in this study to classify the sky types from overcast to clear. The indices can be calculated from measurements of global, diffuse, and direct irradiance that are widely available from meteorological ground stations. The classification system uses confusion matrices, a machine-learning tool that generates a visual display of the results of supervised-learning algorithms. The CIE Standard skies classification, applied to half hourly sky-scanner measurements in Burgos (Spain), over the period June 2016 - May 2017, is used in this study as a baseline reference for a comparative review of the results from the meteorological indices and their results. They are classified by four performance ratings: Accuracy, Jaccard, Cohen, and Matthews, which feature both classification similarity and the randomness of any agreement. All meteorological indices yielded a high average degree of accuracy - close to 80% - in a detailed review of their classification. Neverthless, the results suggested that Perez’s Clearness Index based on global, diffuse and direct radiation measurements offered the most precise classification of the skies, followed closely by the Klucher Clearness Index and the Perraudeau Nebulosity Index.Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (ORDEN EDU/667/2019) and the Spanish Ministry of Science, Innovation & Universities under the I + D + i state programme “Challenges Research Projects” (Ref. RTI2018-098900-B-I00

Modelling Photosynthetic Active Radiation (PAR) through meteorological indices under all sky conditions

In this study, ten-minute meteorological data-sets recorded at Burgos, Spain, are used to develop models of Photosynthetic Active Radiation () following two different procedures: multilinear regression and Artificial Neural Networks. Ten Meteorological Indices (MIs) are chosen as inputs to the models: clearness index (), diffuse fraction (), direct fraction (), Perez's clear sky index (ɛ), brightness index (), cloud cover (), air temperature (), pressure (), solar azimuth cosine (), and horizontal global irradiation (). The experimental data are clustered according to the sky conditions, following the CIE standard sky classification. A previous feature selection procedure established the most adequate MIs for modelling in clear, partial and overcast sky conditions. was the common MI used by all models and for all sky conditions. Additional variables were also included: the geometrical parameter, , and three variables related to the sky conditions, , and Both modelling methods, multilinear regression and ANN, yielded very high determination coefficients () with very close results in the models for each of the different sky conditions. Slight improvements can be observed in the ANN models. The results underline the equivalence of multilinear regression models and ANN models of PAR following previous feature selection procedures.Regional Government of Castilla y León, under projects BU021G19 and INVESTUN/19/BU/0004 and the Spanish Ministry of Science & Innovation under the I+D +i state program “Challenges Research Projects” (Ref. RTI2018-098900-B-I00). Diego Granados López expresses his thanks to the Junta de Castilla y León for economic support (PIRTU Program, ORDEN EDU/556/2019)

Performance of global luminous efficacy models and proposal of a new model for daylighting in Burgos, Spain

Daylighting is recognized as an important and useful strategy in the design of energy efficient buildings. Daylight is still the best source of light for good colour rendering and visual comfort. In this study, a new model of global luminous efficacy over a horizontal surface is proposed. A comparative study of eighteen classic models is presented, to obtain global horizontal illuminance, using both, the original formulation and new formulae with local adaptations, in order to determine the most suitable models for the conditions in Burgos (Spain). With this aim in mind, the selected models consisted of six models developed for all sky conditions, five models for clear sky conditions, three for partly cloudy sky and four for modelling overcast sky conditions. These eighteen models were also compared with the proposed model using experimental global illuminance measurements for different sky conditions. It was shown that the proposed model behaved in a better way than most of the classic models selected from the literature; both for all sky conditions and for particular sky conditions (clear, partly cloudy and overcast). The proposed model was therefore generally applicable, with no need to employ a different model for each particular sky condition.Spanish Government (Ministerio de Economía y Competitividad) (ENE2014-54601-R

Evaluation of the vertical sky component without obstructions for daylighting in Burgos, Spain

Daylight availability knowledge is the first step for an energetic and visually e cient building and city design. It can be estimated with the Vertical Sky Component (VSC), which is defined as the ratio of the vertical di use illuminance over the unobstructed horizontal di use illuminance, simultaneously measured at the same point. These illuminance magnitudes are obtained from luxmeter measurements but these data are scarce. Alternatively, VSC can be obtained from prior knowledge of the sky illuminance distribution, which can be measured with a sky scanner device or by reference to the CIE (Commission Internationale de L’Éclairage) Standard classification for homogeneous skies. Both approaches are compared in this study. The coherence of the results obtained for the four cardinal orientations are analyzed by applying classical statistical parameters and luxmeter measurements as references for the results. The measurement campaign was completed between September 2016 and January 2019 in Burgos (Spain), as representative case study and specific contribution of this work. It was observed that the VSC values were higher than 100 in many cases: 21.94% for the south- and 33.6% for the east-facing vertical surfaces. The study highlights the good daylighting conditions in Burgos, mainly due to the predominance of clear skies over much of the year. This fact implies high daylight availability that, with e cient city planning and building design, could potentially lead reduction energy consumption of buildings, improvements in visual comfort, and the well-being of occupants.Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (ORDEN EDU/667/2019) and the Spanish Ministry of Science, Innovation & Universities under the I+D+i state program “Challenges Research Projects” (Ref. RTI2018-098900-B-I00). Diego Granados López also thankfully acknowledges the economic support from the Junta de Castilla-León (ORDEN EDU/556/2019

Pixel-Based Image Processing for CIE Standard Sky Classification through ANN

Digital sky images are studied for the definition of sky conditions in accordance with the CIE Standard General Sky Guide. Likewise, adequate image-processing methods are analyzed that highlight key image information, prior to the application of Artificial Neural Network classification algorithms. Twenty-two image-processing methods are reviewed and applied to a broad and unbiased dataset of 1500 sky images recorded in Burgos, Spain, over an extensive experimental campaign. The dataset comprises one hundred images of each CIE standard sky type, previously classified from simultaneous sky scanner data. Color spaces, spectral features, and texture filters image-processing methods are applied. While the use of the traditional RGB color space for image-processing yielded good results (ANN accuracy equal to 86.6%), other color spaces, such as Hue Saturation Value (HSV), which may be more appropriate, increased the accuracy of their global classifications. The use of either the green or the blue monochromatic channels improved sky classification, both for the fifteen CIE standard sky types and for simpler classification into clear, partial, and overcast conditions. The main conclusion was that specific image-processing methods could improve ANN-algorithm accuracy, depending on the image information required for the classification problem.Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (BU021G19) and the Spanish Ministry 595 of Science and Innovation under the I + D + i state program “Challenges Research Projects” (Ref. RTI2018-098900-B-I00). Diego Granados López expresses his thanks for economic support from the Junta de Castilla-León (PIRTU Program, ORDEN EDU/556/2019)

European Hernia Society guidelines on management of rectus diastasis

Rectus diastasis; Hernia; GuidelinesDiástasis del recto; Hernia; PautasDiàstasi del recte; Hèrnia; PautesBackground The definition, classification and management of rectus diastasis (RD) are controversial in the literature and a variety of different surgical treatments have been described. This article reports on the European Hernia Society (EHS) Clinical Practice Guideline for RD. Method The Guideline group consisted of eight surgeons. The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach and the Appraisal of Guidelines for Research and Evaluation (AGREE) instrument were used. A systematic literature search was done in November 2018 and updated in November 2019 and October 2020. Nine Key Questions (KQs) were formulated. Results Literature reporting on the definition, classification, symptoms, outcomes and treatments was limited in quality, leading to weak recommendations for the majority of the KQs. The main recommendation is to define RD as a separation between rectus muscles wider than 2 cm. A new classification system is suggested based on the width of muscle separation, postpregnancy status and whether or not there is a concomitant hernia. Impaired body image and core instability appear to be the most relevant symptoms. Physiotherapy may be considered before surgical management. It is suggested to use linea alba plication in patients without concomitant hernia and a mesh-based repair of RD with concomitant midline hernias. Conclusion RD should be defined as a separation of rectus muscles wider than 2 cm and a new classification system is suggested