A finite element-based machine learning approach for modeling the mechanical behavior of the breast tissues under compression in real-time

[EN] This work presents a data-driven method to simulate, in real-time, the biomechanical behavior of the breast tissues in some image-guided interventions such as biopsies or radiotherapy dose delivery as well as to speed up multimodal registration algorithms. Ten real breasts were used for this work. Their deformation due to the displacement of two compression plates was simulated off-line using the finite element (FE) method. Three machine learning models were trained with the data from those simulations. Then, they were used to predict in real-time the deformation of the breast tissues during the compression. The models were a decision tree and two tree-based ensemble methods (extremely randomized trees and random forest). Two different experimental setups were designed to validate and study the performance of these models under different conditions. The mean 3D Euclidean distance between nodes predicted by the models and those extracted from the FE simulations was calculated to assess the performance of the models in the validation set. The experiments proved that extremely randomized trees performed better than the other two models. The mean error committed by the three models in the prediction of the nodal displacements was under 2 man, a threshold usually set for clinical applications. The time needed for breast compression prediction is sufficiently short to allow its use in real-time (< 0.2 s).This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through research projects TIN2014-52033-R and DPI2013-40859-R with the support of European FEDER funds.Martínez Martínez, F.; Rupérez Moreno, MJ.; Martínez-Sober, M.; Solves Llorens, JA.; Lorente, D.; Serrano-Lopez, A.; Martinez-Sanchis, S.... (2017). A finite element-based machine learning approach for modeling the mechanical behavior of the breast tissues under compression in real-time. Computers in Biology and Medicine. 90:116-124. https://doi.org/10.1016/j.compbiomed.2017.09.019S1161249

Impact of a transformation from flood to drip irrigation on groundwater recharge and nitrogen leaching under variable climatic conditions

[EN] The sustainability of agriculture in the Mediterranean climate is challenged by high irrigation water demands and nitrogen fertilizer losses to the environment, causing significant pressure on groundwater resources and groundwater dependent ecosystems. Advanced irrigation technologies and improved fertilizer management have been promoted as key solutions to reduce the agricultural impact on aquatic systems. However, it remains unclear how different irrigation-fertilizer practices perform on the long-term under a highly variable climate, such as the Mediterranean one. Here, we conduct hydrological simulations over a fifty-year period to quantify the magnitude and dynamics of groundwater recharge and nitrogen leaching under five real-case irrigation-fertilizer practices observed in Valencia (eastern Spain). The Valencian Region is the largest citrus-producing region of Europe and current irrigation fertilizer practices reflect the ongoing transformation of irrigation systems from flood to drip irrigation. Our simulations highlight three major implications of the irrigation transformation for groundwater resources. First, the transformation from flood to drip irrigation reduces the recharge fraction (19% vs. 16%) and especially the nitrogen leaching fraction (33%vs. 18%) on the long term. Second, the long-term performance of the two irrigation practices is subject to substantial inter-annual differences controlled by precipitation variability. The sensitivity of recharge and nitrogen leaching to annual meteorological conditions is stronger in drip irrigation, which eventually leads to a similar performance of flood and drip irrigation in wet years if fertilizer inputs are similar. Third, we identify a pronounced year-to-year nitrogen memory in the soil, whereby an enhanced (decreased) nitrogen leaching is observed after anomalously dry (wet) years, affecting the performance of irrigation-fertilizer practices. Overall, the study demonstrates the highly variable nature of the performance of irrigation-fertilizer practices, and the major findings can guide future efforts in designing sustainable water management strategies for agricultural areas with a Mediterranean climate.The authors thank the Coop Research Program on Sustainability in Food Value Chains of the ETH Zurich World Food System Center and the ETH Zurich Foundation for supporting this project. The Coop Research Program is supported by the Coop Sustainability Fund. The authors also acknowledge the financial support from the Spanish Ministry of Science and Innovation through the research project TETISCHANGE (RTI2018-093717-B-100). This work was additionally supported by the ADAPTAMED (RTI2018-101483-BI00) research project funded by the Spanish Ministry of Science and Innovation with European FEDER funds. The authors further thank AEMET and UC for the data provided for this work (Spain02 v5 dataset, available at http://www.meteo.unican.es/datasets/spain02).Pool, S.; Francés, F.; Garcia-Prats, A.; Puertes, C.; Pulido-Velazquez, M.; Sanchis Ibor, C.; Schirmer, M.... (2022). Impact of a transformation from flood to drip irrigation on groundwater recharge and nitrogen leaching under variable climatic conditions. Science of The Total Environment. 825:1-11. https://doi.org/10.1016/j.scitotenv.2022.153805S11182

Evaluation based on the gradient method of the elastic properties of human tissues in vivo

En la actualidad la simulación numérica del comportamiento mecánico de tejidos humanos en el campo de la medicina es un ámbito de estudio que ha despertado gran interés en la comunidad científica. El estudio del comportamiento de dichos tejidos conlleva una gran dificultad, en parte, atribuida al hecho de que el comportamiento de dichos tejidos cambia de paciente a paciente y en numerosas ocasiones no es posible realizar experimentos directos sobre el tejido para determinar sus propiedades elásticas. Para tal fin, en el presente trabajo se propone un método para hallar dichas propiedades asumiendo un modelo constitutivo de Mooney-Rivlin. Dicho método se basa en la información propor- cionada por imágenes médicas en dos situaciones de deformación del órgano y, mediante un proceso de optimización basado en el gradiente se obtienen, con precisión, las propiedades elásticas del modelo constitutivo. Los experimentos numéricos realizados demuestran la validez del método para el ejemplo utilizado.At present, the numerical simulation of the mechanical behavior of human tissues in the field of medicine is a field of study that has aroused great interest in the scientific community. The study of the behavior of these tissues entails a great difficulty, partly attributed to the fact that the behavior of these tissues changes from patient to patient and in many occasions it is not possible to perform direct experiments on the tissue to determine its elastic properties. For this purpose, the present work proposes a method to find these properties assuming a constitutive model of Mooney-Rivlin. This method is based on the information provided by medical images in two situations of organ deformation and, through a process of optimization based on the gradient, the elastic properties of the constitutive model are obtained with precision. The numerical experiments performed demonstrate the validity of the method for the example used

Real-time biomechanical modeling of the liver using Machine Learning models trained on Finite Element Method simulations

[EN] The development of accurate real-time models of the biomechanical behavior of different organs and tissues still poses a challenge in the field of biomechanical engineering. In the case of the liver, specifically, such a model would constitute a great leap forward in the implementation of complex applications such as surgical simulators, computed-assisted surgery or guided tumor irradiation. In this work, a relatively novel approach for developing such a model is presented. It consists in the use of a machine learning algorithm, which provides real-time inference, trained on tens of thousands of simulations of the biomechanical behavior of the liver carried out by the finite element method on more than 100 different liver geometries. Considering a target accuracy threshold of 3 mm for the Euclidean Error, four different scenarios were modeled and assessed: a single liver with an arbitrary force applied (99.96% of samples within the accepted error range), a single liver with two simultaneous forces applied (99.84% samples in range), a single liver with different material properties and an arbitrary force applied (98.46% samples in range), and a much more general model capable of modeling the behavior of any liver with an arbitrary force applied (99.01% samples in range for the median liver). The results show that the Machine Learning models perform extremely well on all the scenarios, managing to keep the Mean Euclidean Error under 1 mm in all cases. Furthermore, the proposed model achieves working frequencies above 100Hz on modest hardware (with frequencies above 1000Hz being easily achievable on more powerful GPUs) thus fulfilling the real-time requirements. These results constitute a remarkable improvement in this field and may involve a prompt implementation in clinical practice.This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through research projects TIN2014-52033-R, also supported by European FEDER funds.Pellicer-Valero, OJ.; Rupérez Moreno, MJ.; Martinez-Sanchis, S.; Martín-Guerrero, JD. (2020). Real-time biomechanical modeling of the liver using Machine Learning models trained on Finite Element Method simulations. Expert Systems with Applications. 143:1-12. https://doi.org/10.1016/j.eswa.2019.113083S112143Abadi, M., Barham, P., Chen, J., Chen, Z., Davis, A., Dean, J., Devin, M., Ghemawat, S., Irving, G., Isard, M., Kudlur, M., Levenberg, J., Monga, R., Moore, S., Murray, D. G., Steiner, B., Tucker, P., Vasudevan, V., Warden, P., Wicke, M., Yu, Y., & Zheng, X. (2016). TensorFlow: A system for large-scale machine learning. arXiv:1605.08695.Brunon, A., Bruyère-Garnier, K., & Coret, M. (2010). Mechanical characterization of liver capsule through uniaxial quasi-static tensile tests until failure. Journal of Biomechanics, 43(11), 2221-2227. doi:10.1016/j.jbiomech.2010.03.038Chinesta, F., Leygue, A., Bordeu, F., Aguado, J. V., Cueto, E., Gonzalez, D., … Huerta, A. (2013). PGD-Based Computational Vademecum for Efficient Design, Optimization and Control. Archives of Computational Methods in Engineering, 20(1), 31-59. doi:10.1007/s11831-013-9080-xClifford, M. A., Banovac, F., Levy, E., & Cleary, K. (2002). Assessment of Hepatic Motion Secondary to Respiration for Computer Assisted Interventions. Computer Aided Surgery, 7(5), 291-299. doi:10.3109/10929080209146038Cotin, S., Delingette, H., & Ayache, N. (2000). A hybrid elastic model for real-time cutting, deformations, and force feedback for surgery training and simulation. The Visual Computer, 16(8), 437-452. doi:10.1007/pl00007215Duysak, A., Zhang, J. J., & Ilankovan, V. (2003). Efficient modelling and simulation of soft tissue deformation using mass-spring systems. International Congress Series, 1256, 337-342. doi:10.1016/s0531-5131(03)00423-0Fung, Y. C., & Skalak, R. (1981). Biomechanics: Mechanical Properties of Living Tissues. Journal of Biomechanical Engineering, 103(4), 231-298. doi:10.1115/1.3138285González, D., Aguado, J. V., Cueto, E., Abisset-Chavanne, E., & Chinesta, F. (2016). kPCA-Based Parametric Solutions Within the PGD Framework. Archives of Computational Methods in Engineering, 25(1), 69-86. doi:10.1007/s11831-016-9173-4González, D., Cueto, E., & Chinesta, F. (2015). Computational Patient Avatars for Surgery Planning. Annals of Biomedical Engineering, 44(1), 35-45. doi:10.1007/s10439-015-1362-zJahya, A., Herink, M., & Misra, S. (2013). A framework for predicting three-dimensional prostate deformation in real time. The International Journal of Medical Robotics and Computer Assisted Surgery, 9(4), e52-e60. doi:10.1002/rcs.1493Lister, K., Gao, Z., & Desai, J. P. (2010). Development of In Vivo Constitutive Models for Liver: Application to Surgical Simulation. Annals of Biomedical Engineering, 39(3), 1060-1073. doi:10.1007/s10439-010-0227-8Lorente, D., Martínez-Martínez, F., Rupérez, M. J., Lago, M. A., Martínez-Sober, M., Escandell-Montero, P., … Martín-Guerrero, J. D. (2017). A framework for modelling the biomechanical behaviour of the human liver during breathing in real time using machine learning. Expert Systems with Applications, 71, 342-357. doi:10.1016/j.eswa.2016.11.037Maas, S. A., Ellis, B. J., Ateshian, G. A., & Weiss, J. A. (2012). FEBio: Finite Elements for Biomechanics. Journal of Biomechanical Engineering, 134(1). doi:10.1115/1.4005694Myronenko, A., & Xubo Song. (2010). Point Set Registration: Coherent Point Drift. IEEE Transactions on Pattern Analysis and Machine Intelligence, 32(12), 2262-2275. doi:10.1109/tpami.2010.46Niroomandi, S., Alfaro, I., Cueto, E., & Chinesta, F. (2012). Accounting for large deformations in real-time simulations of soft tissues based on reduced-order models. Computer Methods and Programs in Biomedicine, 105(1), 1-12. doi:10.1016/j.cmpb.2010.06.012Plantefève, R., Peterlik, I., Haouchine, N., & Cotin, S. (2015). Patient-Specific Biomechanical Modeling for Guidance During Minimally-Invasive Hepatic Surgery. Annals of Biomedical Engineering, 44(1), 139-153. doi:10.1007/s10439-015-1419-zLarge elastic deformations of isotropic materials. I. Fundamental concepts. (1948). Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 240(822), 459-490. doi:10.1098/rsta.1948.0002Large elastic deformations of isotropic materials IV. further developments of the general theory. (1948). Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 241(835), 379-397. doi:10.1098/rsta.1948.0024Ruder, S. (2016). An overview of gradient descent optimization algorithms. (pp. 1–14). arXiv: 1609.04747.Untaroiu, C. D., & Lu, Y.-C. (2013). Material characterization of liver parenchyma using specimen-specific finite element models. Journal of the Mechanical Behavior of Biomedical Materials, 26, 11-22. doi:10.1016/j.jmbbm.2013.05.013Valanis, K. C., & Landel, R. F. (1967). The Strain‐Energy Function of a Hyperelastic Material in Terms of the Extension Ratios. Journal of Applied Physics, 38(7), 2997-3002. doi:10.1063/1.171003

Experiencias y conclusiones en el desarrollo y validación de instrumentos de evaluación enfocados a la adquisición de la competencia transversal ‘CT13 Instrumental Específica’ en asignaturas de Ingeniería Mecánica

[EN] This paper presents the results of the experience carried out in the lab-sessions of several subjects of Mechanical Engineering. The aim of this work is to find a common methodology focused on the acquisition and evaluation of the Specific Instrumental Transversal Competence (CT13 in the UPV institutional project). The work has been applied in two types of lab-sessions: computer lab and laboratory. The instrumentation used in each of them has a different nature, while the former is focused on the use and comprehension of a numerical calculation software, in the latter the students must understand the management and purpose of some experimental measurement equipments. In the computer sessions, after an accompanied learning, the students must carry out and justify the steps followed in solving a numerical problem. The evaluation takes into account the level of adequacy of the steps followed throughout the process. In the laboratory practices, the students must demonstrate the ability to correctly select the proper equipment based on the parameter to be measured as well as to define the sequence of treatments in the measurement process. The measurement of the level of acquisition of the CT13 is done through an individual questionnaire.[ES] En este trabajo se presentan los resultados de la experiencia llevada a cabo en las prácticas de diversas asignaturas de Ingeniería Mecánica. El objetivo final es encontrar una metodología unificada enfocada a la adquisición y evaluación de la Competencia Transversal Instrumental Específica (CT13 en el proyecto institucional de la UPV).Se ha trabajado con dos tipos de prácticas: informáticas y de laboratorio. La instrumentación empleada en cada una de ellas tiene distinta naturaleza, mientras las primeras están enfocadas al manejo de un programa de cálculo numérico, en las segundas los estudiantes deben comprender el manejo y la finalidad de diversos equipos de medida experimental.En las prácticas informáticas los alumnos, tras un aprendizaje acompañado, deben ser capaces de realizar y justificar los pasos seguidos en la resolución de un problema numérico. En la evaluación se tiene en cuenta el nivel de adecuación de los pasos seguidos a lo largo del proceso. En las prácticas de laboratorio los alumnos deben demostrar la capacidad de seleccionar correctamente el equipo adecuado en función del parámetro a medir, así como definir la secuencia de tratamientos en el proceso experimental. La medida del nivel de adquisición de la CT13 se realiza con un cuestionario individual.Los autores agradecen la financiación recibida del Vicerrectorado de Estudios, Calidad y Acreditación, el Vicerrectorado de Recursos Digitales y Documentación (proyecto PIME B/19-20/165) y el Instituto de Ciencias de la Educación de la Universitat Politècnica de València (EICE INTEGRAL).Pedrosa Sanchez, AM.; Besa Gonzálvez, AJ.; Rupérez Moreno, MJ.; Sánchez Orgaz, EM.; Giner Navarro, J.; Martinez Sanchis, S.; Vila Tortosa, MP.... (2021). Experiencias y conclusiones en el desarrollo y validación de instrumentos de evaluación enfocados a la adquisición de la competencia transversal ‘CT13 Instrumental Específica’ en asignaturas de Ingeniería Mecánica. En IN-RED 2021: VII Congreso de Innovación Edicativa y Docencia en Red. Editorial Universitat Politècnica de València. 1521-1532. https://doi.org/10.4995/INRED2021.2021.13771OCS1521153

Jardins per a la salut

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia. Assignatura: Botànica farmacèutica. Curs: 2014-2015. Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són el recull de les fitxes botàniques de 128 espècies presents en el Jardí Ferran Soldevila de l’Edifici Històric de la UB. Els treballs han estat realitzats manera individual per part dels estudiants dels grups M-3 i T-1 de l’assignatura Botànica Farmacèutica durant els mesos de febrer a maig del curs 2014-15 com a resultat final del Projecte d’Innovació Docent «Jardins per a la salut: aprenentatge servei a Botànica farmacèutica» (codi 2014PID-UB/054). Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pels professors de l’assignatura. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica. També s’ha pretès motivar els estudiants a través del retorn de part del seu esforç a la societat a través d’una experiència d’Aprenentatge-Servei, deixant disponible finalment el treball dels estudiants per a poder ser consultable a través d’una Web pública amb la possibilitat de poder-ho fer in-situ en el propi jardí mitjançant codis QR amb un smartphone

Evaluación basada en el método del gradiente de las propiedades elásticas de tejidos humanos in vivo

At present, the numerical simulation of the mechanical behavior of human tissues in the field of medicine is a field of study that has aroused great interest in the scientific community. The study of the behavior of these tissues entails a great difficulty, partly attributed to the fact that the behavior of these tissues changes from patient to patient and in many occasions it is not possible to perform direct experiments on the tissue to determine its elastic properties. For this purpose, the present work proposes a method to find these properties assuming a constitutive model of Mooney-Rivlin. This method is based on the information provided by medical images in two situations of organ deformation and, through a process of optimization based on the gradient, the elastic properties of the constitutive model are obtained with precision. The numerical experiments performed demonstrate the validity of the method for the example used.En la actualidad la simulación numérica del comportamiento mecánico de tejidos humanos en el campo de la medicina es un ámbito de estudio que ha despertado gran interés en la comunidad científica. El estudio del comportamiento de dichos tejidos conlleva una gran dificultad, en parte, atribuida al hecho de que el comportamiento de dichos tejidos cambia de paciente a paciente y en numerosas ocasiones no es posible realizar experimentos directos sobre el tejido para determinar sus propiedades elásticas. Para tal fin, en el presente trabajo se propone un método para hallar dichas propiedades asumiendo un modelo constitutivo de Mooney-Rivlin. Dicho método se basa en la información propor- cionada por imágenes médicas en dos situaciones de deformación del órgano y, mediante un proceso de optimización basado en el gradiente se obtienen, con precisión, las propiedades elásticas del modelo constitutivo. Los experimentos numéricos realizados demuestran la validez del método para el ejemplo utilizado

Evaluation based on the gradient method of the elastic properties of human tissues in vivo

En la actualidad la simulación numérica del comportamiento mecánico de tejidos humanos en el campo de la medicina es un ámbito de estudio que ha despertado gran interés en la comunidad científica. El estudio del comportamiento de dichos tejidos conlleva una gran dificultad, en parte, atribuida al hecho de que el comportamiento de dichos tejidos cambia de paciente a paciente y en numerosas ocasiones no es posible realizar experimentos directos sobre el tejido para determinar sus propiedades elásticas. Para tal fin, en el presente trabajo se propone un método para hallar dichas propiedades asumiendo un modelo constitutivo de Mooney-Rivlin. Dicho método se basa en la información propor- cionada por imágenes médicas en dos situaciones de deformación del órgano y, mediante un proceso de optimización basado en el gradiente se obtienen, con precisión, las propiedades elásticas del modelo constitutivo. Los experimentos numéricos realizados demuestran la validez del método para el ejemplo utilizado.At present, the numerical simulation of the mechanical behavior of human tissues in the field of medicine is a field of study that has aroused great interest in the scientific community. The study of the behavior of these tissues entails a great difficulty, partly attributed to the fact that the behavior of these tissues changes from patient to patient and in many occasions it is not possible to perform direct experiments on the tissue to determine its elastic properties. For this purpose, the present work proposes a method to find these properties assuming a constitutive model of Mooney-Rivlin. This method is based on the information provided by medical images in two situations of organ deformation and, through a process of optimization based on the gradient, the elastic properties of the constitutive model are obtained with precision. The numerical experiments performed demonstrate the validity of the method for the example used

Alfabetización transmedia y lectura multimodal en el estudio de la Literatura Infantil y Juvenil. Innovación digital y LIJ 2.0 en asignaturas de Didáctica de la Lengua y la Literatura (4644)

En este curso 2019-2020, la red 4644 ha realizado distintas investigaciones sobre las posibilidades de la lectura multimodal y las narrativas transmedia en la formación del profesorado, desde la etapa de Educación Infantil hasta los Másteres de Formación del Profesorado e Investigación Educativa, produciendo ocho publicaciones distintas. Se han analizado las posibilidades didácticas del póster académico, herramientas para el estudio del baby-talk, la creación de relatos literarios y multimodales a través de constelaciones literarias, guías de lectura sobre la Biblioteca Virtual Miguel de Cervantes o las posibilidades de la literatura infantil y juvenil de temática LGTB. Además del trabajo de los doce integrantes de la red, se ha colaborado con profesorado de otras universidades que han realizado estancias en nuestro departamento y alumnado del programa de doctorado en Investigación Educativa, consolidando la red como un espacio de investigación en nuevas formas de lectura para la Didáctica de la Lengua y la Literatura

3D geometric morphometric analysis of variation in the human lumbar spine

[Objectives]: The shape of the human lumbar spine is considered to be a consequence of erect posture. In addition, several other factors such as sexual dimorphism and variation in genetic backgrounds also influence lumbar vertebral morphology. Here we use 3D geometric morphometrics (GM) to analyze the 3D morphology of the lumbar spine in different human populations, exploring those potential causes of variation.[Material and methods]: We collected 390 (semi) landmarks from 3D models of the CT scans of lumbar spines of seven males and nine females from a Mediterranean population (Spain, Israel) and seven males and either females from a South African population for geometric morphometric (GM) analysis. We carried out Generalized Procrustes Analysis, Principal Components, and Regression analyses to evaluate shape variation; and complemented these analyses with the Cobb Method.[Results]: The Mediterranean sample was considerably more lordotic than the South African sample. In both populations, female lumbar spines showed proportionally narrower and more craniocaudally elongated lumbar segments than in males. In addition, the point of maximum curvature in females tended to be located more inferiorly than in males.[Discussion]: Our results show that sexual dimorphism is an important factor of lumbar spine variation that mainly affects features of lumbar spine robustness (height proportions) and the structure—but not the degree—of its curvature. Differences in lordosis, however, are clearer at the inter-population level. This reflects previous conflicting studies casting doubts on pregnancy as an adaptive factor influencing lordosis. Other factors, for example, shape of the individual lumbar vertebrae and intervertebral discs and their relative proportions within the lumbar spine should be considered when exploring variation in vertebral column morphology.This research is funded by CGL‐2015‐63648‐P (Ministry of Economy, Industry and Competitiveness, Spain) and Project BF14_005 (ERESA Clinic Research Foundation Valencia)