28 research outputs found

    Estudio del comportamiento hidrológico de una pequeña cuenca forestal

    Full text link
    [ES] La finalidad del estudio es la determinación del caudal pico de escorrentía para una cuenca de pequeño tamaño situada en la provincia de Valencia. La escorrentía, o cantidad de agua que circula por la superficie de una cuenca, es responsable de importantes procesos erosivos, además puede poner en peligro la integridad de gran cantidad de obras públicas como carreteras, canales o embalses, o incluso dar lugar a inundaciones. La correcta determinación de la escorrentía permite estudiar estos procesos y generar planes de actuación. En el presente proyecto se ha llevado a cabo un estudio hidrológico de una cuenca de aproximadamente 800 Ha, situada entre los términos municipales de Alcira y Corbera. El tratamiento de los datos necesarios, se ha realizado utilizando Sistema de Información Geográfico, principalmente en lo relativo a la obtención de los parámetros que relacionan la precipitación con la escorrentía. Los cálculos de escorrentía se han realizado por el Método Racional y el Método del Número de Curva.[EN] The aim of this project is to determine the peak flow for a small river basin placed in the region of Valencia, Spain. The runoff, or quantity of water flowing on the surface of a river basin, is responsible for important erosion processes. It can also entail a risk for a wide number of infrastructures such as channels, roads or reservoirs. Ultimately, it may even cause a flood. Determining runoff correctly allows us to study all this processes and create useful prevention plans. Collected data has been processed using Geographical Information Systems, mostly to obtain the parameters that relate rainfall and runoff flow. Runoff calculation has been carried out by using the Rational Formula and the Curve Number Method.Barbero García, I. (2014). Estudio del comportamiento hidrológico de una pequeña cuenca forestal. Universitat Politècnica de València. http://hdl.handle.net/10251/49260Archivo delegad

    Spherical harmonics to quantify cranial asymmetry in deformational plagiocephaly

    Full text link
    [EN] Cranial deformation and deformational plagiocephaly (DP) in particular affect an important percentage of infants. The assessment and diagnosis of the deformation are commonly carried by manual measurements that provide low interuser accuracy. Another approach is the use of three-dimensional (3D) models. Nevertheless, in most cases, deformation measurements are carried out manually on the 3D model. It is necessary to develop methodologies for the detection of DP that are automatic, accurate and take profit on the high quantity of information of the 3D models. Spherical harmonics are proposed as a new methodology to identify DP from head 3D models. The ideal fitted ellipsoid for each head is computed and the orthogonal distances between head and ellipsoid are obtained. Finally, the distances are modelled using spherical harmonics. Spherical harmonic coefficients of degree 2 and order - 2 are identified as the correct ones to represent the asymmetry characteristic of DP. The obtained coefficient is compared to other anthropometric deformation indexes, such as Asymmetry Index, Oblique Cranial Length Ratio, Posterior Asymmetry Index and Anterior Asymmetry Index. The coefficient of degree 2 and order - 2 with a maximum degree of 4 is found to provide better results than the commonly computed anthropometric indexes in the detection of DP.This article was funded by Instituto de Salud Carlos III and European Regional Development Fund (FEDER) (Grant no. PI18/00881).Grieb, J.; Barbero-García, I.; Lerma, JL. (2022). Spherical harmonics to quantify cranial asymmetry in deformational plagiocephaly. Scientific Reports. 12(1):1-10. https://doi.org/10.1038/s41598-021-04181-z11012

    Análisis de repetibilidad en videogrametría para la evaluación de la deformación craneal en niños

    Full text link
    [EN] Cranial deformation affects a large number of infants. The methodologies commonly employed to measure the deformation include, among others, calliper measurements and visual assessment for mild cases and radiological imaging for severe cases, where surgical intervention is considered. Visual assessment and calliper measurements usually lack the required level of accuracy to evaluate the deformation. Radiological imaging, including Computed Tomography (CT) and Magnetic Resonance Imaging (MRI), are costly and highly invasive. The use of smartphones to record videos that can be used for three-dimensional (3D) modelling of the head has emerged as a low-cost, noninvasive methodology to extract 3D information of the patient. To be able to analyse the deformation, a novel technique is employed: the obtained model is compared with an ideal head. In this study we have tested the repeatability of the process. For this purpose, several models of two patients have been obtained and the differences between them are evaluated. The results show that the differences in the ellipsoid semiaxis for the same patient are usually below 4 mm, although they increase up to 6.4 mm in some cases. The variability in the distances to the ideal head, which are the values used to evaluate deformity, reaches a maximum value of 2.7 mm. The errors obtained are comparable to those of classical measurement techniques and show the potential of the methodology in development.[ES] La deformación craneal afecta a un elevado porcentaje de lactantes, a pesar de esto, no existen estándares para su medición. Existen diversas metodologías empleadas para el análisis de este tipo de deformación, que van desde el análisis visual o la medición con calibre en casos leves, a pruebas radiológicas en casos más graves, en los que se plantea la posibilidad de una intervención quirúrgica. El análisis visual y la medición con calibre a menudo carecen de la precisión requerida para evaluar la deformación, mientras que las pruebas radiológicas (Tomografía Axial Computarizada, TAC, o Resonancia Magnética, RM) son altamente invasivas y tienen un alto coste. Otras soluciones como la fotografía tridimensional (3D) incluyen complejos sistemas de varias cámaras, lo que también supone un coste elevado. La posibilidad de utilizar videos tomados con teléfonos inteligentes para la creación de modelos 3D craneales se ha convertido en una posibilidad para obtener información 3D del paciente de forma precisa y con un coste bajo. Para analizar la deformación se ha planteado una metodología que consiste en calcular las distancias entre el modelo generado y una forma craneal ideal. En este estudio se ha llevado a cabo el análisis de la repetibilidad del proceso de obtención del modelo y de la cabeza ideal ajustada, para ello se han obtenido varios modelos 3D de dos pacientes y se han evaluado las diferencias entre ellos. Los resultados muestran unas diferencias en los semiejes de los elipsoides de aproximadamente 4 mm, aunque este error llega a incrementarse hasta 6.4 mm en algunos casos. La variabilidad en las distancias del modelo a la cabeza ideal, empleadas para medir la deformidad tienen un máximo de 2.7 mm. Las precisiones obtenidas con esta metodología son comparables a las obtenidas mediante técnicas de análisis tradicionales y muestran el potencial de la metodología en desarrollo.This work was supported by Subprogram C (No. C10) for the development of coordinated actions between the UPV and the IIS La Fe.Barbero García, I.; Lerma García, JL.; Marqués Mateu, Á.; Miranda, P. (2017). Analysis of repeatability on videogrammetry for infants' cranial deformation. En Primer Congreso en Ingeniería Geomática. Libro de actas. Editorial Universitat Politècnica de València. 15-19. https://doi.org/10.4995/CIGeo2017.2017.6604OCS151

    Fully automatic smartphone-based photogrammetric 3D modelling of infant¿s heads for cranial deformation analysis

    Full text link
    [EN] Image-based and range-based solutions can be used for the acquisition of valuable data in medicine. However, most of these methods are not valid for non-static patients. Cranial deformation is a problem with high prevalence among infants and image-based solutions can be used to assess the degree of deformation and monitor the evolution of patients. However, it is required to deal with infants normal movement during the assessment in order to avoid sedation. Some high-end multiple-sensor image-based solutions allow the achievement of accurate 3D data for medical applications under unpredicted dynamic conditions in consultation. In this paper, a novel, single photogrammetric smartphone-based solution for cranial deformation assessment is presented. A coded cap is placed on the infant's head and a guided smartphone app is used by the user to acquire the information, that is later processed on a server to obtain the 3D model. The smartphone app is designed to guide users with no knowledge of photogrammetry, computer vision or 3D modelling. The processing is fully automatic offline. The photogrammetric tool is also non-invasive, reacting well with quick and sudden infant's movements. Therefore, it does not require sedation. This paper tackles the accuracy and repeatability analysis tested both for a single user (intrauser) and multiple non-expert user (interuser) on 3D printed head models. The results allow us to confirm an accuracy below 1.5 mm, which makes the system suitable for clinical practice by medical staff. The basic automatically-derived anthropometric linear magnitudes are also tested obtaining a mean variability of 0.6 +/- 0.6 mm for the longitudinal and transversal distances and 1.4 +/- 1.3 mm for the maximum perimeter.This project is funded by Instituto de Salud Carlos III and European Regional Development Fund (FEDER), project number PI18/00881, and by Generalitat Valenciana, grant number ACIF/2017/056.Barbero-García, I.; Lerma, JL.; Mora Navarro, JG. (2020). Fully automatic smartphone-based photogrammetric 3D modelling of infant¿s heads for cranial deformation analysis. ISPRS Journal of Photogrammetry and Remote Sensing. 166:268-277. https://doi.org/10.1016/j.isprsjprs.2020.06.013S268277166Aldridge, K., Boyadjiev, S. A., Capone, G. T., DeLeon, V. B., & Richtsmeier, J. T. (2005). Precision and error of three-dimensional phenotypic measures acquired from 3dMD photogrammetric images. American Journal of Medical Genetics Part A, 138A(3), 247-253. doi:10.1002/ajmg.a.30959Argenta, L. (2004). Clinical Classification of Positional Plagiocephaly. Journal of Craniofacial Surgery, 15(3), 368-372. doi:10.1097/00001665-200405000-00004Ballardini, E., Sisti, M., Basaglia, N., Benedetto, M., Baldan, A., Borgna-Pignatti, C., & Garani, G. (2018). Prevalence and characteristics of positional plagiocephaly in healthy full-term infants at 8–12 weeks of life. European Journal of Pediatrics, 177(10), 1547-1554. doi:10.1007/s00431-018-3212-0Barbero-García, I., Cabrelles, M., Lerma, J. L., & Marqués-Mateu, Á. (2018). Smartphone-based close-range photogrammetric assessment of spherical objects. The Photogrammetric Record, 33(162), 283-299. doi:10.1111/phor.12243Barbero-García, I., Lerma, J. L., Marqués-Mateu, Á., & Miranda, P. (2017). Low-Cost Smartphone-Based Photogrammetry for the Analysis of Cranial Deformation in Infants. World Neurosurgery, 102, 545-554. doi:10.1016/j.wneu.2017.03.015Barbero-García, I., Lerma, J. L., Miranda, P., & Marqués-Mateu, Á. (2019). Smartphone-based photogrammetric 3D modelling assessment by comparison with radiological medical imaging for cranial deformation analysis. Measurement, 131, 372-379. doi:10.1016/j.measurement.2018.08.059Bay, H., Ess, A., Tuytelaars, T., Gool, L. Van, 2007. Speeded-Up Robust Features (SURF). https://doi.org/10.1016/j.cviu.2007.09.014.Bernardini, F., Mittleman, J., Rushmeier, H., Silva, C., & Taubin, G. (1999). The ball-pivoting algorithm for surface reconstruction. IEEE Transactions on Visualization and Computer Graphics, 5(4), 349-359. doi:10.1109/2945.817351Besl, P.J., McKay, N.D., 1992. Method for registation of 3-D shapes. In: Schenker, P.S. (Ed.), Sensor Fusion IV: Control Paradigms and Data Structures. SPIE, pp. 586–606. https://doi.org/10.1117/12.57955.Camison, L., Bykowski, M., Lee, W. W., Carlson, J. C., Roosenboom, J., Goldstein, J. A., … Weinberg, S. M. (2018). Validation of the Vectra H1 portable three-dimensional photogrammetry system for facial imaging. International Journal of Oral and Maxillofacial Surgery, 47(3), 403-410. doi:10.1016/j.ijom.2017.08.008Caple, J. M., Stephan, C. N., Gregory, L. S., & MacGregor, D. M. (2015). Effect of Head Position on Facial Soft Tissue Depth Measurements Obtained Using Computed Tomography. Journal of Forensic Sciences, 61(1), 147-152. doi:10.1111/1556-4029.12896Cignoni, P., Callieri, M., Corsini, M., Dellepiane, M., Ganovelli, F., Ranzuglia, G., 2008. MeshLab: an Open-Source Mesh Processing Tool. In: Scarano, V., Chiara, R. De, Erra, U. (Eds.), Eurographics Italian Chapter Conference. The Eurographics Association. https://doi.org/10.2312/LocalChapterEvents/ItalChap/ItalianChapConf2008/129-136.Collett, B. R., Wallace, E. R., Kartin, D., Cunningham, M. L., & Speltz, M. L. (2019). Cognitive Outcomes and Positional Plagiocephaly. Pediatrics, 143(2), e20182373. doi:10.1542/peds.2018-2373De Jong, G., Tolhuisen, M., Meulstee, J., van der Heijden, F., van Lindert, E., Borstlap, W., … Delye, H. (2017). Radiation-free 3D head shape and volume evaluation after endoscopically assisted strip craniectomy followed by helmet therapy for trigonocephaly. Journal of Cranio-Maxillofacial Surgery, 45(5), 661-671. doi:10.1016/j.jcms.2017.02.007De Jong, G. A., Maal, T. J. J., & Delye, H. (2015). The computed cranial focal point. Journal of Cranio-Maxillofacial Surgery, 43(9), 1737-1742. doi:10.1016/j.jcms.2015.08.023Dörhage, K. W. W., Wiltfang, J., von Grabe, V., Sonntag, A., Becker, S. T., & Beck-Broichsitter, B. E. (2018). Effect of head orthoses on skull deformities in positional plagiocephaly: Evaluation of a 3-dimensional approach. Journal of Cranio-Maxillofacial Surgery, 46(6), 953-957. doi:10.1016/j.jcms.2018.03.013Farkas, L.G., 1994. Anthropometry of the Head and Face. Raven Pr.Garrido-Jurado, S., Muñoz-Salinas, R., Madrid-Cuevas, F. J., & Medina-Carnicer, R. (2016). Generation of fiducial marker dictionaries using Mixed Integer Linear Programming. Pattern Recognition, 51, 481-491. doi:10.1016/j.patcog.2015.09.023Goebbels, S., Pohle-Fröhlich, R., Pricken, P., 2019. Iterative closest point algorithm for accurate registration of coarsely registered point clouds with CityGML models. In: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences. pp. 201–208. https://doi.org/10.5194/isprs-annals-IV-2-W5-201-2019.Grazioso, S., Selvaggio, M., Caporaso, T., & Di Gironimo, G. (2019). A Digital Photogrammetric Method to Enhance the Fabrication of Custom-Made Spinal Orthoses. JPO Journal of Prosthetics and Orthotics, 31(2), 133-139. doi:10.1097/jpo.0000000000000244Heymsfield, S.B., Bourgeois, B., Ng, B.K., Sommer, M.J., Li, X., Shepherd, J.A., 2018. Digital anthropometry: A critical review. In: European Journal of Clinical Nutrition. Nature Publishing Group, pp. 680–687. https://doi.org/10.1038/s41430-018-0145-7.Hsu, C.-K., Hallac, R. R., Denadai, R., Wang, S.-W., Kane, A. A., Lo, L.-J., & Chou, P.-Y. (2019). Quantifying normal head form and craniofacial asymmetry of elementary school students in Taiwan. Journal of Plastic, Reconstructive & Aesthetic Surgery, 72(12), 2033-2040. doi:10.1016/j.bjps.2019.09.005Jodeh, D. S., Curtis, H., Cray, J. J., Ford, J., Decker, S., & Rottgers, S. A. (2018). Anthropometric Evaluation of Periorbital Region and Facial Projection Using Three-Dimensional Photogrammetry. Journal of Craniofacial Surgery, 29(8), 2017-2020. doi:10.1097/scs.0000000000004761Khormi, Y., Chiu, M., Goodluck Tyndall, R., Mortenson, P., Smith, D., & Steinbok, P. (2019). Safety and efficacy of independent allied healthcare professionals in the assessment and management of plagiocephaly patients. Child’s Nervous System, 36(2), 373-377. doi:10.1007/s00381-019-04400-zKournoutas, I., Vigo, V., Chae, R., Wang, M., Gurrola, J., Abla, A. A., … Rubio, R. R. (2019). Acquisition of Volumetric Models of Skull Base Anatomy Using Endoscopic Endonasal Approaches: 3D Scanning of Deep Corridors Via Photogrammetry. World Neurosurgery, 129, 372-377. doi:10.1016/j.wneu.2019.05.251Lopes Alho, E.J., Rondinoni, C., Furokawa, F.O., Monaco, B.A., 2019. Computer-assisted craniometric evaluation for diagnosis and follow-up of craniofacial asymmetries: SymMetric v. 1.0. Child’s Nerv. Syst. 1–7. https://doi.org/10.1007/s00381-019-04451-2.Lowe, D.G., 1999. Object recognition from local scale-invariant features. In: Proceedings of the International Conference on Computer Vision-Volume 2 - Volume 2, ICCV ’99. IEEE Computer Society, Washington, DC, USA, p. 1150.Lübbers, H.-T., Medinger, L., Kruse, A., Grätz, K. W., & Matthews, F. (2010). Precision and Accuracy of the 3dMD Photogrammetric System in Craniomaxillofacial Application. Journal of Craniofacial Surgery, 21(3), 763-767. doi:10.1097/scs.0b013e3181d841f7Martiniuk, A. L. C., Vujovich-Dunn, C., Park, M., Yu, W., & Lucas, B. R. (2017). Plagiocephaly and Developmental Delay: A Systematic Review. Journal of Developmental & Behavioral Pediatrics, 38(1), 67-78. doi:10.1097/dbp.0000000000000376Meulstee, J. W., Verhamme, L. M., Borstlap, W. A., Van der Heijden, F., De Jong, G. A., Xi, T., … Maal, T. J. J. (2017). A new method for three-dimensional evaluation of the cranial shape and the automatic identification of craniosynostosis using 3D stereophotogrammetry. International Journal of Oral and Maxillofacial Surgery, 46(7), 819-826. doi:10.1016/j.ijom.2017.03.017Mitchell, H. ., & Newton, I. (2002). Medical photogrammetric measurement: overview and prospects. ISPRS Journal of Photogrammetry and Remote Sensing, 56(5-6), 286-294. doi:10.1016/s0924-2716(02)00065-5Mortenson, P. A., & Steinbok, P. (2006). Quantifying Positional Plagiocephaly. Journal of Craniofacial Surgery, 17(3), 413-419. doi:10.1097/00001665-200605000-00005Munn, L., & Stephan, C. N. (2018). Changes in face topography from supine-to-upright position—And soft tissue correction values for craniofacial identification. Forensic Science International, 289, 40-50. doi:10.1016/j.forsciint.2018.05.016Muñoz-Salinas, R., Marín-Jimenez, M. J., Yeguas-Bolivar, E., & Medina-Carnicer, R. (2018). Mapping and localization from planar markers. Pattern Recognition, 73, 158-171. doi:10.1016/j.patcog.2017.08.010Nahles, S., Klein, M., Yacoub, A., & Neyer, J. (2018). Evaluation of positional plagiocephaly: Conventional anthropometric measurement versus laser scanning method. Journal of Cranio-Maxillofacial Surgery, 46(1), 11-21. doi:10.1016/j.jcms.2017.10.010Nocerino, E., Poiesi, F., Locher, A., Tefera, Y.T., Remondino, F., Chippendale, P., Van Gool, L., 2017. 3D Reconstruction with a Collaborative Approach Based on Smartphones and a Cloud-based Server. ISPRS - Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci. XLII-2/W8, 187–194. https://doi.org/10.5194/isprs-archives-XLII-2-W8-187-2017.Patias, P. (2002). Medical imaging challenges photogrammetry. ISPRS Journal of Photogrammetry and Remote Sensing, 56(5-6), 295-310. doi:10.1016/s0924-2716(02)00066-7Pierrot Deseilligny, M., & Clery, I. (2012). APERO, AN OPEN SOURCE BUNDLE ADJUSMENT SOFTWARE FOR AUTOMATIC CALIBRATION AND ORIENTATION OF SET OF IMAGES. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XXXVIII-5/W16, 269-276. doi:10.5194/isprsarchives-xxxviii-5-w16-269-2011Romero-Ramirez, F. J., Muñoz-Salinas, R., & Medina-Carnicer, R. (2018). Speeded up detection of squared fiducial markers. Image and Vision Computing, 76, 38-47. doi:10.1016/j.imavis.2018.05.004Siegenthaler, M. H. (2015). Methods to Diagnose, Classify, and Monitor Infantile Deformational Plagiocephaly and Brachycephaly: A Narrative Review. Journal of Chiropractic Medicine, 14(3), 191-204. doi:10.1016/j.jcm.2015.05.003Sirazitdinova, E., Deserno, T.M., 2017. System Design for 3D Wound Imaging Using Low-Cost Mobile Devices. In: Cook, T.S., Zhang, J. (Eds.), Proc. SPIE 10138, Medical Imaging 2017: Imaging Informatics for Healthcare, Research, and Applications. International Society for Optics and Photonics. https://doi.org/10.3233/978-1-61499-830-3-1237.Urbanová, P., Hejna, P., & Jurda, M. (2015). Testing photogrammetry-based techniques for three-dimensional surface documentation in forensic pathology. Forensic Science International, 250, 77-86. doi:10.1016/j.forsciint.2015.03.005Ursitti, F., Fadda, T., Papetti, L., Pagnoni, M., Nicita, F., Iannetti, G., & Spalice, A. (2011). Evaluation and management of nonsyndromic craniosynostosis. Acta Paediatrica, 100(9), 1185-1194. doi:10.1111/j.1651-2227.2011.02299.xWang, C., Zhang, Y., & Zhou, X. (2018). Robust Image Watermarking Algorithm Based on ASIFT against Geometric Attacks. Applied Sciences, 8(3), 410. doi:10.3390/app8030410Wilbrand, J.-F., Wilbrand, M., Pons-Kuehnemann, J., Blecher, J.-C., Christophis, P., Howaldt, H.-P., & Schaaf, H. (2011). Value and reliability of anthropometric measurements of cranial deformity in early childhood. Journal of Cranio-Maxillofacial Surgery, 39(1), 24-29. doi:10.1016/j.jcms.2010.03.010Wong, J. Y., Oh, A. K., Ohta, E., Hunt, A. T., Rogers, G. F., Mulliken, J. B., & Deutsch, C. K. (2008). Validity and Reliability of Craniofacial Anthropometric Measurement of 3D Digital Photogrammetric Images. The Cleft Palate-Craniofacial Journal, 45(3), 232-239. doi:10.1597/06-17

    Smartphone-based video for 3D modelling: Application to infants cranial deformation analysis

    Full text link
    [EN] The use of smartphones cameras for photogrammetric purposes is increasing. However, the suitability of smartphones for 3D modelling for medical purposes in general, and for cranial deformation in particular, is still to be analysed. This paper investigates the suitability of smartphone video cameras to create 3D models for cranial deformation analysis compared to the digital single-lens reflex (SLR) cameras traditionally used in close-range photogrammetry. Two models are obtained, the first one from a slow-motion video recorded with a smartphone, and the second one from SLR camera imagery. The models are compared to evaluate the differences not only between themselves but also through the best fitting ellipsoid that allow the determination of the cranial deformations. The average distance between models is 0.5¿mm, and below 1¿mm for 86% of the model points. The maximum difference between the two fitted ellipsoid semiaxes is 1¿mm. It can be stated that smartphones are a low-cost solution that can provide 3D models with a similar accuracy to that of SLR cameras for non-static objects in close range scenarios. More interestingly, slow-motion videos provide comparable results in real clinical conditions with infants in movement.The authors acknowledge the partial support from the Subprogram C (No. C10) to the development of coordinated actions between the Universitat Politecnica de Valencia and the Hospital Universitari i Politecnic/Instituto de Investigacion Sanitaria La Fe.Lerma, JL.; Barbero-García, I.; Marqués-Mateu, Á.; Miranda, P. (2018). Smartphone-based video for 3D modelling: Application to infants cranial deformation analysis. Measurement. 116:299-306. https://doi.org/10.1016/j.measurement.2017.11.019S29930611

    Smartphone-based photogrammetric 3D modelling assessment by comparison with radiological medical imaging for cranial deformation analysis

    Full text link
    [EN] Cranial deformation in infants is a common problem in paediatric consultations. The most accurate medical diagnostic imaging methodologies are Computed Tomography (CT) and Magnetic Resonance Image (MRI). However, these radiological imaging technologies involve high costs and are invasive, especially for infants. Therefore, they are only used for severe cases, while milder cases are evaluated using less precise methodologies, such as callipers or measure tapes. The use of smartphone-based photogrammetric 3D models has been presented as a possible alternative to extracting accurate and complete external information in a low-cost, non-invasive manner but its accuracy is still to be tested. In this study, photogrammetric and radiological cranial 3D models have been obtained for a set of 10 patients. In order to compare them, the distances between model surfaces have been calculated. Results show an overestimation of the photogrammetric models up to 3.2 mm due to both hair and usage of caps. However, differences in shape, given by the standard deviation of the distances are below 1.5 mm for every patient. The accuracy of low-cost smartphone-based photogrammetric models has been found to be comparable to medical diagnostic imaging methodologies used for cranial deformation analysis. (C) 2018 Elsevier Ltd. All rights reserved.This study was supported by Conselleria d Educació of the Generalitat Valenciana and the European Social Fund under the grant number ACIF/2017/056. The authors also acknowledge the partial support from the 2017 Subprogram B No. B03 (Acronym HEAD3D++) to the development of coordinated actions between the Universitat Politècnica de València and the Hospital Universitari i Politècnic/Instituto de Investigación Sanitaria La Fe.Barbero-García, I.; Lerma, JL.; Miranda, P.; Marqués-Mateu, Á. (2019). Smartphone-based photogrammetric 3D modelling assessment by comparison with radiological medical imaging for cranial deformation analysis. Measurement. 131:372-379. https://doi.org/10.1016/j.measurement.2018.08.059S37237913

    Smartphone-based close-range photogrammetric assessment of spherical objects

    Full text link
    [FR] Les smartphones ont élargi les possibilités d'acquisition d'images rapprochées à moindre coût pour la modélisation 3D. Ils permettent l'acquisition d'une grande quantité de données pour une grande variété d'applications. Toutefois, la précision des modèles et les possibilités d'automatisation dépendent des conditions d'acquisition des images et des exigences des applications. Dans cette étude, la précision et la fiabilité des modèles photogrammétriques 3D obtenus sont évalués sur une cible sphérique dédiée aux applications rapprochées (diamètre d'environ 30 cm). Différents nombres d'images, configurations de canevas, cibles, matériels et méthodes d¿étalonnage de la caméra sont testés et évalués. Les résultats montrent que pour cette application en mode rapproché, une précision de 0,2 mm et une grande fiabilité peuvent être obtenues. Le nombre d'images n'affecte pas la précision de manière significative mais il est vital pour la détection des points de liaison et pour l'orientation des images. L'utilisation de cibles artificielles s'est avéré crucial pour l'amélioration de la précision finale. Au contraire, la stratégie d¿étalonnage des images et les caractéristiques du capteur n'ont eu que peu d'effet sur les résultats.[ES] Los teléfonos inteligentes han ampliado las posibilidades en la toma de imágenes para modelado tridimensional (3D) de objeto cercano con bajo coste. Estos dispositivos permiten la obtención de gran cantidad de imágenes que pueden usarse en diferentes aplicaciones. La precisión de los modelos y la posibilidad de automatización dependen de las condiciones durante la toma de datos y las necesidades de la aplicación. En este estudio la precisión y la fiabilidad de los modelos fotogramétricos 3D se evalúan para una aplicación de objeto cercano (30 cm) sobre una superficie esférica. Se ha evaluado diferente número de conjuntos de imágenes, la geometría de la red, el dispositivo, la existencia de dianas y la metodología de calibración. Los resultados muestran que en esta aplicación de objeto cercano pueden obtenerse altas precisiones (0·2 mm) y una alta fiabilidad. El número de imágenes no afecta en gran medida a la precisión de los resultados, pero sí a la posibilidad de obtener suficientes puntos homólogos para la creación del modelo. El uso de dianas es el factor que más ha aumentado la precisión. Por otro lado, la metodología de calibración de la cámara apenas ha mejorado la precisión de los resultados.[EN] Smartphones have widened the possibilities for low-cost close-range image acquisition for three-dimensional (3D) modelling. They allow the rapid acquisition of large amounts of data for a wide range of applications. However, the accuracy of the models and the automation possibilities depend on the image acquisition conditions and application requirements. In this study, the accuracy and reliability of the derived photogrammetric 3D models are evaluated on a spherical set¿up for close¿range applications (c.30 cm). Different numbers of images, network configurations, targets, devices and camera calibration methodologies are tested and evaluated. Results show that for this close-range application high accuracy (0·2 mm) and reliability can be achieved. The number of images did not significantly affect the accuracy but was vital for tie-point detection and image orientation. The use of artificial targets was found to be the key factor in increasing the final accuracy. In contrast, the image calibration strategy and the characteristics of the imaging device did not have a great impact on the results.[DE] Smartphones haben die Möglichkeiten für kostengünstige Erfassung von 3D-Modellen im Nahbereich erweitert. Große Datenmengen können in sehr kurzer Zeit für eine Vielzahl von Anwendungen erfasst werden. Allerdings hängen die Genauigkeit der Modelle und die Möglichkeiten einer Automatisierung sehr stark von den Aufnahmebedingungen und den Anforderungen der Anwendung ab. In diesem Beitrag werden Genauigkeits- und Zuverlässigkeitsaspekte der abgeleiteten 3D-Modelle in einer sphärischen Messanordnung für Nahbereichsanwendungen (c.30 cm) evaluiert. Unterschiedliche Bildanzahl, Aufnahmeanordnungen, Zielmarken, Geräte und Kamerakalibrierungsmethoden werden geprüft und ausgewertet. Die Ergebnisse zeigen, dass für diese Anwendung eine sehr hohe Genauigkeit (0·2 mm) und Zuverlässigkeit erzielt werden kann. Die Zahl der Aufnahmen hat keinen signifikanten Einfluss auf die Genauigkeit, war aber Voraussetzung für die Detektion von Verknüpfungspunkten und die Bildorientierung. Der Einfluss künstlicher Zielmarken hatte einen entscheidenden Einfluss, um die Genauigkeit des Ergebnisses zu erhöhen. Hingegen hatten die Strategie zur Bildkalibrierung und die Eigenschaften des Bildaufnahmesystems keinen großen Einfluss auf die Ergebnisse.This study was partially supported by grant number ACIF/2017/056 from the Conselleria d'Educacio of the Generalitat Valenciana and the European Social Fund. The authors also acknowledge the support from the 2017 Subprogram B No. B03 (HEAD3D++) to the development of coordinated actions between the Universitat Politecnica de Valencia and the Hospital Universitari i Politecnic/Instituto de Investigacion Sanitaria La Fe.Barbero-García, I.; Cabrelles, M.; Lerma, JL.; Marqués-Mateu, Á. (2018). Smartphone-based close-range photogrammetric assessment of spherical objects. The Photogrammetric Record. 33(162):283-299. https://doi.org/10.1111/phor.12243S2832993316

    Experimental response of agglomerated cork under multi-impact loads

    Get PDF
    In contrast to other cellular materials, which deform by crushing under impact and develop permanent deformation, agglomerated cork has a viscoelastic response and is environmentally friendly; therefore, it could be a good alternative to be used in engineering applications subjected to more than one impact, and thus further understanding of the energy-absorption capabilities of this material under multi-impact conditions is needed. In this work the multi-impact behaviour of agglomerated cork was studied experimentally by performing several consecutive impacts in a drop-weight tower on specimens of different thickness and at two impact energy levels. The maximum contact force, maximum strain, and the absorbed energy were evaluated in each test. The results show the great capability of agglomerated cork to continue absorbing energy after several consecutive impacts.Publicad

    Impact response of repaired sandwich structures

    Get PDF
    The low-velocity impact behavior of repaired sandwich structures with woven carbon/epoxy face-sheets and Nomex honeycomb core is studied experimentally. First, sandwich plates were subjected to ballistic impacts; the damaged area was removed, filled by nano-enhanced resin and covered by a double-external patch. Afterwards, the repaired sandwich plates were impacted at low-velocity. Peak load and absorbed energy were determined for several impact energies and compared with results for non-repaired (intact) sandwich plates. For all impact energies tested, repaired specimens show higher peak load and lower absorbed energy than the intact ones. Additionally, tested sandwich plates were cut transversally in order to observe the resulting damage, concluding that is different in both configurations, and confirming that it is initiated at higher impact energies in repaired structures.Fundação para a Ciência e a Tecnologia, Grant/Award Number: UID/EMS/00285/2020; Ministerio de Economía, Industria y Competitividad, Gobierno de España, Grant/Award Number: DPI2017-86324-R

    Association of IFN-γ +874 A/T SNP and hypermethylation of the -53 CpG site with tuberculosis susceptibility

    Get PDF
    Introduction: Tuberculosis (TB) is now the 2nd leading infectious killer after COVID-19 and the 13th leading cause of death worldwide. Moreover, TB is a lethal combination for HIV-patients. Th1 responses and particularly IFN-γ are crucial for immune protection against Mycobacterium tuberculosis infection. Many gene variants for IFNG that confer susceptibility to TB have been described in multiple ethnic populations. Likewise, some epigenetic modifications have been evaluated, being CpG methylation the major epigenetic mark that makes chromatin inaccessible to transcription factors, thus avoiding the initiation of IFNG transcription. Methods: We evaluated both genetic and epigenetic changes involved in IFN-γ production and TB susceptibility in Argentine population. Amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) was performed for the IFN-γ +874 A/T polymorphism (rs2430561) genotyping in 199 healthy donors (HD) and 173 tuberculosis (TB) patients. IFN-γ levels from M. tuberculosis-stimulated PBMCs were measured by ELISA. The methylation status at the -53 CpG site of the IFNG promoter in individuals with latent infection (LTBI), TB and HD was determine by pyrosequencing. Results: Using a case-control study, we found that A allele and, consequently, AA genotype were overrepresented in patients with active disease. Moreover, HD carrying T allele (AT or TT genotype) evidenced an augmented IFN-γ secretion compared to TB patients. Codominance was the genetic model that best fits our results according to the Akaike information criterion (AIC). In addition, increased methylation levels at the -53 CpG site in the IFN-γ promoter were observed in whole blood of patients with active TB compared to LTBI individuals. Discussion: IFN-γ is regulated by genetic variants and epigenetic modifications during TB. Besides, AA genotype of the rs2430561 single nucleotide polymorphism could be considered as a potential TB susceptibility genetic biomarker in Argentina and the methylation of the -53 CpG site could result in a useful predictor of TB reactivation.Fil: Alvarez, Guadalupe Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Hernández del Pino, Rodrigo Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Barbero, Angela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Estermann, Martín Andrés. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Celano, Josefina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Musella, Rosa María. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Palmero, Domingo Juan. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: García, Verónica Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Pasquinelli, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentin
    corecore