Comparative Analysis between 3D-Printed Models Designed with Generic and Dental-Specific Software.

With the great demand in the market for new dental software, the need has been seen to carry out a precision study for applications in digital dentistry, for which there is no comparative study, and there is a general ignorance regarding their applications. The purpose of this study was to investigate the accuracy differences between digital impressions obtained using generic G-CAD (general CAD) and D-CAD (CAD dental) software. Today, there is a difference between the design software used in dentistry and these in common use. Thus, it is necessary to make a comparison of precision software for specific and generic dental use. We hypothesized that there is no significant difference between the software for specific and general dental use. METHODS: A typodont was digitized with an intraoral scanner and the models obtained were exported in STL format to four different softwares (Autodesk MeshMixer 3.5, Exocad Dental, Blender for dental, and InLAB). The STL files obtained by each software were materialized using a 3D printer. The printed models were scanned and exported in STL files, with which six pairs of groups were formed. The groups were compared using analysis software (3D Geomagic Control X) by superimposing them in the initial alignment order and using the best fit method. RESULTS: There were no significant differences between the four analyzed software types; however, group 4, composed of the combination of D-CAD (Blender-InLAB), obtained the highest average (-0.0324 SD = 0.0456), with a higher accuracy compared to the group with the lowest average (group 5, composed of the combination of the Meshmixer and Blender models), a generic software and a specific software (0.1024 SD = 0.0819). CONCLUSION: Although no evidence of significant difference was found regarding the accuracy of 3D models produced by G-CAD and D-CAD, combinations of groups where specific dental design software was present showed higher accuracy (precision and trueness). The comparison of the 3D graphics obtained with the superimposition of the digital meshes of the printed models performed with the help of the analysis software using the best fit method, replicating the same five reference points for the six groups formed, evidenced a greater tolerance in the groups using D-CAD.

3D analysis of maxillomandibular morphology in hyperdivergent and hypodivergent individuals: A cross-sectional study.

INTRODUCTION: The aim of this cross-sectional study was to investigate maxillomandibular morphology in hyperdivergent and hypodivergent individuals, using 3D surface models generated by cone-beam computed tomography (CBCT). METHODS: The sample consisted of 60 CBCTs (30 males, 30 females) patients aged 12-30 years, divided into two groups comprising hyperdivergent (≥35°) and hypodivergent (≤30°) individuals, according to the mandibular plane (MP) angle. Multiplanar reconstructions were used to mark the landmarks, and 3D surface models were created to evaluate structures of the maxillomandibular complex, including condyle, ramus, symphysis and palatal height. Intergroup comparisons were performed by independent t-test. Pearson's correlation test was used (P < .05) to evaluate the correlation of the MP angle with the angles and linear measurements of other structures. RESULTS: Significant differences were found between the groups regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. No differences (P > .05) were found for the condylar height, symphysis inclination angle or palatal height. Correlations (P < .05) were found between the MP angle and structures of the maxillomandibular complex. CONCLUSIONS: Hyperdivergent (MP ≥ 35°) and hypodivergent (MP ≤ 30°) individuals present different skeletal morphology regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. There is a significant correlation between MP angle and morphological structures such as condyle, ramus, symphysis, palatal plane angle and palatal-mandibular angle.

Tissue Engineering Challenges for Cultivated Meat to Meet the Real Demand of a Global Market.

Cultivated meat (CM) technology has the potential to disrupt the food industry-indeed, it is already an inevitable reality. This new technology is an alternative to solve the environmental, health and ethical issues associated with the demand for meat products. The global market longs for biotechnological improvements for the CM production chain. CM, also known as cultured, cell-based, lab-grown, in vitro or clean meat, is obtained through cellular agriculture, which is based on applying tissue engineering principles. In practice, it is first necessary to choose the best cell source and type, and then to furnish the necessary nutrients, growth factors and signalling molecules via cultivation media. This procedure occurs in a controlled environment that provides the surfaces necessary for anchor-dependent cells and offers microcarriers and scaffolds that favour the three-dimensional (3D) organisation of multiple cell types. In this review, we discuss relevant information to CM production, including the cultivation process, cell sources, medium requirements, the main obstacles to CM production (consumer acceptance, scalability, safety and reproducibility), the technological aspects of 3D models (biomaterials, microcarriers and scaffolds) and assembly methods (cell layering, spinning and 3D bioprinting). We also provide an outlook on the global CM market. Our review brings a broad overview of the CM field, providing an update for everyone interested in the topic, which is especially important because CM is a multidisciplinary technology.

Reprogramming of tumor-associated macrophages by polyaniline-coated iron oxide nanoparticles applied to treatment of breast cancer.

Breast cancer is the most commonly diagnosed type of cancer among the female population worldwide. It is a disease with a high incidence and geographic distribution that negatively impacts global public health and deleteriously affect the quality of life of cancer patients. Among the new approaches, cancer immunotherapy is the most promising trend in oncology by stimulating the host's own immune system to efficiently destroy cancer cells. Recent evidence has indicated that iron oxide nanoparticles can promote the reprograming of M2 into M1 macrophages with anti-tumor effects in the tumor microenvironment. Thus, the aim of the present work was to evaluate the ability of polyaniline-coated maghemite (Pani/γ-Fe2O3) nanoparticles to modulate human macrophages in 2D monolayers and 3D multicellular breast cancer models. It was observed that Pani/γ-Fe2O3 NPs re-educated IL-10-stimulated macrophages towards a pro-inflammatory profile, decreasing the proportion of CD163+ and increasing the CD86+ proportion in 2D models. NPs were successfully taken-up by macrophages presented in the 3D model and were also able to induce an increasing in their CD86+ proportion in triple MCTs model. Overall, our findings open new perspectives on the use of Pani/γ-Fe2O3 NPs as an immunomodulatory therapy for macrophage reprogramming towards an anti-tumor M1 phenotype, providing a new tool for breast cancer immunotherapies.

3D Multi-Modality Medical Imaging: Combining Anatomical and Infrared Thermal Images for 3D Reconstruction.

Medical thermography provides an overview of the human body with two-dimensional (2D) information that assists the identification of temperature changes, based on the analysis of surface distribution. However, this approach lacks spatial depth information, which can be enhanced by adding multiple images or three-dimensional (3D) systems. Therefore, the methodology applied for this paper generates a 3D point cloud (from thermal infrared images), a 3D geometry model (from CT images), and the segmented inner anatomical structures. Thus, the following computational processing was employed: Structure from Motion (SfM), image registration, and alignment (affine transformation) between the 3D models obtained to combine and unify them. This paper presents the 3D reconstruction and visualization of the respective geometry of the neck/bust and inner anatomical structures (thyroid, trachea, veins, and arteries). Additionally, it shows the whole 3D thermal geometry in different anatomical sections (i.e., coronal, sagittal, and axial), allowing it to be further examined by a medical team, improving pathological assessments. The generation of 3D thermal anatomy models allows for a combined visualization, i.e., functional and anatomical images of the neck region, achieving encouraging results. These 3D models bring correlation of the inner and outer regions, which could improve biomedical applications and future diagnosis with such a methodology.

[Treatment of severe spinal deformity with 3D printing models]. / Tratamiento de deformidad severa de la columna vertebral con modelos de impresión 3D.

INTRODUCTION: Scoliosis is a complex deformity that affects all three planes of the axis of the spine. The association between neuromuscular pathology and vertebral alignment was initially described in 1960. Neuromuscular pathology is progressive and results in postural abnormalities. Surgical goals in patients with neuromuscular deformity include anatomical correction for sedation and ambulation, as well as functional improvement. The gold standard of treatment is by posterior approach with transpedicular screws. The "hands-free" technique saves surgical time, decreases radiation by reducing the use of fluoroscopy. The advent of 3D printing technology allows precise study of the anatomical area and detail of the deformity in its three planes. This model can be sterilized for transoperative guidance. A 13-year-old female patient who develops thoracolumbar neuromuscular scoliosis secondary to spastic cerebral palsy (CP), with previous instrumentation T11-L3 of which he develops severe proximal curve. After the segmentation of the three-dimensional model, pedicle violation greater than 2 mm towards bilateral medullary canal was detected in the pedicles of L1 and L2 of previous instrumentation, pedicle dysplasia and the morphological characteristics of the pedicles were observed. Three-dimensional planning and the use of surgical guides represent a tool for surgical planning, especially in severe cases and with pedicle dysplasia. It helps as a surgical guide for the placement of hands-free transpedicular screws with possible reduction of radiation and anesthetic time.

INTRODUCCIÓN: La escoliosis es una deformidad compleja que afecta los tres planos del eje de la columna vertebral. La asociación entre patología neuromuscular y la alineación vertebral fue descrita inicialmente en 1960. La patología neuromuscular es progresiva y resulta en anormalidades posturales. Las metas quirúrgicas en pacientes con deformidad neuromuscular engloban la corrección anatómica para la sedestación y deambulación, así como mejoría funcional. El estándar de oro de tratamiento es por vía posterior con tornillos transpediculares. La técnica de "manos libres" ahorra tiempo quirúrgico, disminuye la radiación al reducir el uso de fluoroscopía. El advenimiento de la tecnología de impresión 3D permite estudio preciso del área anatómica y detalle de la deformidad en sus tres planos. Este modelo puede ser esterilizado para guía transoperatoria. Paciente femenino de 13 años de edad que desarrolla escoliosis neuromuscular toracolumbar secundario a parálisis cerebral infantil (PCI) espástica, con instrumentación previa T11-L3 de la cual desarrolla curva severa proximal. Finalizada la segmentación del modelo tridimensional se detectó violación pedicular mayor a 2 mm hacia canal medular bilateral en los pedículos de L1 y L2 de instrumentación previa, displasia pedicular y se observaron las características morfológicas de los pedículos. La planeación tridimensional y el uso de guías quirúrgicas representan una herramienta para la planeación quirúrgica, sobre todo en casos severos y con displasia pedicular. Ayuda como guía quirúrgica para la colocación de tornillos transpediculares a manos libres con posible reducción de radiación y tiempo anestésico.

Accuracy of photogrammetric technologies for the scanning of dental models: A systematic review / Precisión de las tecnologías fotogramétricas para el escaneo de modelos dentales: Una revisión sistemática

Background:Traditional dental scanners require a heavy investment, representing a high barrier of entry into digital dentistry. Photogrammetric-based scanners may represent an affordable cost-effective alternative to traditional dental scanners used for the digitalization of plaster models. Photogrammetry is the science of extracting 3D information from photographs. The process involves taking overlapping photographs of an object or space and converting them into 2D or 3D digital models. Objective:This review aimedto identify and appraise the reported accuracy of photogrammetric-generated digital dental models.Materials and methods:A search strategy was applied in 3 databases (Medline, Web of Science and Scopus), from Feb 1 2021 to Dec 1 2021, the search was limited to articles in English published in the last 5 years about studies evaluating the dimensional accuracy of 3-dimensional digital models acquired by the scanning of plaster models with photogrammetric technologies.Results:Two independent reviewers screened 75 records on basis of titles and abstracts for assessment against the inclusion criteria for the review, 4 articles were deemed eligible, the risk of bias for the selected articles was measured, data extraction was performed by only one author.Conclusion:With today's technology, based on the four studies evaluated, we conclude that photogrammetric-generated digital models while lacking accuracy for incorporation into the treatment flow, in the future it could be used for diagnostic, planning, and achieving.

Antecedentes:Los escáneres dentales tradicionales requieren una gran inversión, lo que representa una gran barrera de entrada a la odontología digital. Los escáneres basados en fotogrametría pueden representar una alternativa asequible y rentable a los escáneres dentales tradicionales utilizados para la digitalización de modelos de yeso. La fotogrametría es la ciencia de extraer información 3D de fotografías. El proceso implica tomar fotografías superpuestas de un objeto o espacio y convertirlas en modelos digitales 2D o 3D.Objetivo:esta revisión tuvo como objetivo identificar y evaluar la precisión informada de los modelos dentales digitales generados fotogramétricamente.Materiales y métodos:Se aplicó una estrategia de búsqueda en 3 bases de datos (Medline, Web of Science y Scopus), del 1 de febrero de 2021 al 1 de diciembre de 2021, la búsqueda se limitó a artículos en inglés publicados en los últimos 5 años sobre estudios que evalúan la dimensión precisión de modelos digitales tridimensionales adquirida por el escaneo de modelos de yeso con tecnologías fotogramétricas.Resultados:dos revisores independientes examinaron 75 registros sobre la base de títulos y resúmenes para evaluarlos según los criterios de inclusión para la revisión, 4 artículos se consideraron elegibles, se midió el riesgo de sesgo de los artículos seleccionados, la extracción de datos fue realizada por un solo autor.Conclusión:con la tecnología actual, con base en los cuatro estudios evaluados, concluimos que los modelos digitales generados por fotogrametría si bien carecen de precisión para incorporarlos al flujo de tratamiento, en el futuro podrían usarse para el diagnóstico, la planificación y el logro.

Tratamiento de deformidad severa de la columna vertebral con modelos de impresión 3D / Treatment of severe spinal deformity with 3D printing models

Resumen: Introducción: La escoliosis es una deformidad compleja que afecta los tres planos del eje de la columna vertebral. La asociación entre patología neuromuscular y la alineación vertebral fue descrita inicialmente en 1960. La patología neuromuscular es progresiva y resulta en anormalidades posturales. Las metas quirúrgicas en pacientes con deformidad neuromuscular engloban la corrección anatómica para la sedestación y deambulación, así como mejoría funcional. El estándar de oro de tratamiento es por vía posterior con tornillos transpediculares. La técnica de «manos libres¼ ahorra tiempo quirúrgico, disminuye la radiación al reducir el uso de fluoroscopía. El advenimiento de la tecnología de impresión 3D permite estudio preciso del área anatómica y detalle de la deformidad en sus tres planos. Este modelo puede ser esterilizado para guía transoperatoria. Paciente femenino de 13 años de edad que desarrolla escoliosis neuromuscular toracolumbar secundario a parálisis cerebral infantil (PCI) espástica, con instrumentación previa T11-L3 de la cual desarrolla curva severa proximal. Finalizada la segmentación del modelo tridimensional se detectó violación pedicular mayor a 2 mm hacia canal medular bilateral en los pedículos de L1 y L2 de instrumentación previa, displasia pedicular y se observaron las características morfológicas de los pedículos. La planeación tridimensional y el uso de guías quirúrgicas representan una herramienta para la planeación quirúrgica, sobre todo en casos severos y con displasia pedicular. Ayuda como guía quirúrgica para la colocación de tornillos transpediculares a manos libres con posible reducción de radiación y tiempo anestésico.

Abstract: Introduction: Scoliosis is a complex deformity that affects all three planes of the axis of the spine. The association between neuromuscular pathology and vertebral alignment was initially described in 1960. Neuromuscular pathology is progressive and results in postural abnormalities. Surgical goals in patients with neuromuscular deformity include anatomical correction for sedation and ambulation, as well as functional improvement. The gold standard of treatment is by posterior approach with transpedicular screws. The «hands-free¼ technique saves surgical time, decreases radiation by reducing the use of fluoroscopy. The advent of 3D printing technology allows precise study of the anatomical area and detail of the deformity in its three planes. This model can be sterilized for transoperative guidance. A 13-year-old female patient who develops thoracolumbar neuromuscular scoliosis secondary to spastic cerebral palsy (CP), with previous instrumentation T11-L3 of which he develops severe proximal curve. After the segmentation of the three-dimensional model, pedicle violation greater than 2 mm towards bilateral medullary canal was detected in the pedicles of L1 and L2 of previous instrumentation, pedicle dysplasia and the morphological characteristics of the pedicles were observed. Three-dimensional planning and the use of surgical guides represent a tool for surgical planning, especially in severe cases and with pedicle dysplasia. It helps as a surgical guide for the placement of hands-free transpedicular screws with possible reduction of radiation and anesthetic time.

The Use of Digital Twins in Finite Element for the Study of Induction Motors Faults.

Induction motors play a key role in the industrial sector. Thus, the correct diagnosis and classification of faults on these machines are important, even in the initial stages of evolution. Such analysis allows for increased productivity, avoids unexpected process interruptions, and prevents damage to machines. Usually, fault diagnosis is carried out by analyzing the characteristic effects caused by the faults. Thus, it is necessary to know and understand the behavior during the operation of the faulty machine. In general, monitoring these characteristics is complex, as it is necessary to acquire signals from the same motor with and without failures for comparison purposes. Whether in an industrial environment or in laboratories, the experimental characterization of failures can become unfeasible for several reasons. Thus, computer simulation of faulty motors digital twins can be an important alternative for failure analysis, especially in large motors. From this perspective, this paper presents and discusses several limitations found in the technical literature that can be minimized with the implementation of digital twins. In addition, a 3D finite element model of an induction motor with broken rotor bars is demonstrated, and motor current signature analysis is used to verify the fault effects. Results are analyzed in the time and frequency domain. Additionally, an artificial neural network of the multilayer perceptron type is used to classify the failure of broken bars in the 3D model rotor.

The Effects of Fibrotic Cell Type and Its Density on Atrial Fibrillation Dynamics: An In Silico Study.

Remodeling in atrial fibrillation (AF) underlines the electrical and structural changes in the atria, where fibrosis is a hallmark of arrhythmogenic structural alterations. Fibrosis is an important feature of the AF substrate and can lead to abnormal conduction and, consequently, mechanical dysfunction. The fibrotic process comprises the presence of fibrotic cells, including fibroblasts, myofibroblasts and fibrocytes, which play an important role during fibrillatory dynamics. This work assesses the effect of the diffuse fibrosis density and the intermingled presence of the three types of fibrotic cells on the dynamics of persistent AF. For this purpose, the three fibrotic cells were electrically coupled to cardiomyocytes in a 3D realistic model of human atria. Low (6.25%) and high (25%) fibrosis densities were implemented in the left atrium according to a diffuse fibrosis representation. We analyze the action potential duration, conduction velocity and fibrillatory conduction patterns. Additionally, frequency analysis was performed in 50 virtual electrograms. The tested fibrosis configurations generated a significant conduction velocity reduction, where the larger effect was observed at high fibrosis density (up to 82% reduction in the fibrocytes configuration). Increasing the fibrosis density intensifies the vulnerability to multiple re-entries, zigzag propagation, and chaotic activity in the fibrillatory conduction. The most complex propagation patterns were observed at high fibrosis densities and the fibrocytes are the cells with the largest proarrhythmic effect. Left-to-right dominant frequency gradients can be observed for all fibrosis configurations, where the fibrocytes configuration at high density generates the most significant gradients (up to 4.5 Hz). These results suggest the important role of different fibrotic cell types and their density in diffuse fibrosis on the chaotic propagation patterns during persistent AF.

Three-dimensional digitalized and printed tongue models of the cow, dog, pig, and horse for undergraduate veterinary educationh / Modelos tridimensionales digitalizados e impresos de lengua de vaca, perro, cerdo y caballo para la educación veterinaria de pregrado

SUMMARY: This study aimed to construct three-dimensional (3D) anatomical models of the tongue of domestic mammals of veterinary interest. The tongues were obtained from the didactic collection of the Laboratory of Veterinary Macroscopic Anatomy in the Surgery Department of the School of Veterinary Medicine and Animal Science, University of Sao Paulo. Tongues from a cow, dog, horse, and pig were selected for scanning and creation of the 3D-printed models. The printer used a filamentous thermoplastic material, acrylonitrile-butadiene-styrene (ABS), which was deposited together with a support resin. In addition to the printing of models, an interactive 3D PDF was generated, creating a didactic collection for students. The anatomical characteristics and peculiarity of the tongues were easily identified in the scanned and printed images. The 3D scanning and printing offered an innovative method of visualizing different anatomical structures and, together with the existing methods, can optimize anatomy teaching in an educational context.

RESUMEN: Este estudio tuvo como objetivo construir modelos anatómicos tridimensionales (3D) de la lengua de mamíferos domésticos de interés veterinario. Las lenguas se obtuvieron de la colección didáctica del Laboratorio de Anatomía Macroscópica Veterinaria del Departamento de Cirugía de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad de São Paulo. Se seleccionaron lenguas de vaca, perro, caballo y cerdo para escanear y crear los modelos impresos en 3D. La impresora utilizó un material termoplástico filamentoso, acrilonitrilo-butadieno-estireno (ABS), que se depositó junto con una resina de soporte. Además de la impresión de modelos, se generó un PDF 3D interactivo, creando una colección didáctica para los estudiantes. Las características anatómicas y la peculiaridad de las lenguas se identificaron fácilmente en las imágenes escaneadas e impresas. El escaneo e impresión 3D ofrecieron un método innovador para visualizar diferentes estructuras anatómicas y, junto con los métodos existentes, puede optimizar la enseñanza de la anatomía en un contexto educativo.

Three-dimensional models increase the interobserver agreement for the treatment of proximal humerus fractures.

BACKGROUND: The agreement for the treatment of proximal humerus fractures is low. Interpretation of exams used for diagnosis can be directly associated with this limitation. This study proposes to compare the agreement between experts and residents in orthopedics for treatment indication of proximal humerus fractures, utilizing 3D-models, holography (augmented reality), x-rays, and tomography as diagnostic methods. METHODS: Twenty orthopedists (ten experts in shoulder and elbow surgery and ten experts in traumatology) and thirty resident physicians in orthopedics evaluated nine fractures of the proximal humerus, randomly distributed as x-rays, tomography, 3D-models and holography, using the Neer and AO / OTA Classifications. After, we evaluated the interobserver agreement between treatment options (conservative, osteosynthesis and arthroplasty) and whether the experience of the evaluators interfered with the results. RESULTS: The interobserver agreement analysis showed the following kappa-values: κ = 0.362 and κ = 0.306 for experts and residents (3D-models); κ = 0.240 and κ = 0.221 (X-ray); κ = 0.233 and κ = 0.123 (Tomography) and κ = 0.321 and κ = 0.160 (Holography), for experts and residents respectively. Moreover, residents and specialists were discordant in the treatment indication using Tomography as a diagnostic method (p = 0.003). The same was not seen for the other diagnostic methods (p > 0.05). CONCLUSIONS: Three-dimensional models showed, overall, the highest interobserver agreement (experts versus residents in orthopedics) for the choice of treatment of proximal humerus fractures compared to X-ray, Tomography, and Holography. Agreement in the choice of treatment among experts that used Tomography and Holography as diagnostic methods were two times higher compared to residents. TRIAL REGISTRATION: Registered in Brazil Platform under no. CAAE 12273519.7.0000.5505.

Comparación estadística entre modelo de yeso, digitalizado e impreso en 3D / Statistic comparison of digitalized plaster models and printed in 3D

Se realizaron mediciones en los ejes x, y, z sobre modelos dentales de yeso, digitalizados e impresos con impresoras 3D, con fines comparativos, estadísticos y evaluativos, cuyo objetivo fue estimar el grado de coincidencia significativa entre los modelos, realizados por dos profesionales, en dos momentos diferentes. Los resultados arrojaron datos de gran precisión en forma y tamaño en los tres estudios, con mínima distorsión (no significativa, p =0,05), lo que determinó la importancia de implementación en forma institucional o privado el estudio digital de los mismos, para realizar comparaciones, mediciones, diagnósticos y acopio de modelos virtuales en un ordenador, siendo estos más precisos y de menor tiempo de trabajo (AU)

Measurements were made in the x, y, z axes on gypsum dental models, digitized and printed with 3D printers, for comparative, statistical and evaluative purposes, whose objective was estimate the degree of significant coincidence between models, that were made by two professionals, at two different times.The results were the achieve of data with a great shape´s and size´s precisionat the three studies, with minimal distortion (not significant, p = 0.05), which determined the importance of the institutional or private way of an implementation of the model´s digital studies, with the aim of doing comparisons, measurements, diagnostics, and collection of virtual models in a computer, to being more precise and with less work time (AU)

Percepción de los estudiantes de anatomía humana frente a un método de enseñanza y aprendizaje basado en la construcción de un modelo de pelvis / Perception of human anatomy students facing a learning and teaching methodology based on the construction of a pelvis model

RESUMEN: Este estudio describe la percepción de estudiantes de anatomía humana frente a la actividad de construcción de modelos tridimensionales (3-D) a escala de pelvis. Pocos estudios evalúan la percepción de los estudiantes frente a una actividad de enseñanza y aprendizaje con modelos 3-D. La actividad se aplicó a un curso de anatomía humana de la carrera de obstetricia y puericultura a los cuales se les entregó modelos de estructuras óseas de la zona pélvica a escala real para que incorporaran las estructuras anatómicas (ligamentos, músculos, vascularización e inervación), finalizando la actividad se les entregó un cuestionario de percepción. 60 estudiantes realizaron la actividad de construcción de modelo anatómico 3-D y además completaron el cuestionario. Se reportaron niveles mayores al 93 % de estudiantes que sintieron motivación, creen que fue un facilitador del aprendizaje y que la actividad fue bien planificada. Entre los aspectos negativos se registraron: el tiempo de trabajo y los costos involucrados. Dada la positiva percepción de los estudiantes frente a las actividades de construcción de modelos anatómicos, se considera que es una metodología adecuada dentro de los procesos de enseñanza y aprendizaje de la anatomía humana.

SUMMARY: In this study, the perception of human anatomy students faced with constructing a three-dimensional (3-D) pelvis model (to scale) was studied. Few studies evaluate the perception of students facing learning and teaching methodologies with 3-D models. The activity was performed with students from a human anatomy course as part of the obstetrics degree, in which models of pelvic zone bone structures (to scale) were supplied in order to incorporate the anatomic structures (ligaments, muscles, vascularization and innervation). Once the activity was finished, a perception questionnaire was taken. 60 students participated in the activity of constructing the 3-D anatomical model and also completed the questionnaire. It was found that over 93 % of the students felt motivated, believed the activity facilitated learning and also that the activity was well planned. Some of the negative factors that were reported included time taken and the associated costs. Due to the positive perception of the students involved in the activity of constructing anatomical models, this is considered to be a suitable methodology for use during the process of teaching and learning about human anatomy.

EFECTO DEL REMODELADO ELÉCTRICO AURICULAR EN UN MODELO TRIDIMENSIONAL DE AURÍCULA HUMANA

Las arritmias cardíacas más frecuentes en humanos tienen origen auricular. El modelado de la actividad auricular se ha convertido en una importante herramienta en el análisis de arritmias como la fibrilación auricular. Estudios experimentales han demostrado que la fibrilación auricular tiende a perpetuarse, generando cambios electrofisiológicos denominados remodelado auricular. En este trabajo se presenta un modelo tridimensional geométricamente realista de la aurícula humana, al cual se le incorporan: anisotropía, dirección de las fibras y heterogeneidad en la conductividad. En un modelo del potencial de acción acoplado al modelo tridimensional, se estudió el efecto del remodelado auricular sobre el potencial de acción y su propagación teniendo en cuenta sus efectos sobre las corrientes iónicas. El modelo reprodujo el comportamiento de la actividad eléctrica en toda la superficie auricular. El remodelado redujo la duración del potencial de acción, el periodo refractario efectivo y la velocidad de conducción. Los resultados sugieren que en el modelo tridimensional desarrollado, es posible simular la actividad eléctrica auricular en condiciones fisiológicas y con remodelado eléctrico auricular.

The most common cardiac arrhythmias in humans originate in the atrium. Modelling of the atrial activity has become an important tool to analyze arrhythmias such as atrial fibrillation. Experimental studies have shown that atrial fibrillation tends to be perpetual, generating electrophysiological changes called atrial remodeling. In this study we present a geometrically realistic three-dimensional (3D) model of human atrium, which incorporates anisotropy, direction of the fibers and conductive heterogeneity. The effects of remodeling on the ionic currents were applied to an action potential model coupled to the 3D model. The effects of remodeling on the action potential and its propagation were studied the model reproduced the electrical activity behavior across the atrial surface. Remodelling induced a reduction in the action potential duration, the effective refractory period and the conduction velocity. Our results suggest that in the developed 3D model of human atrium is possible to simulate the atrial electrical activity under physiological conditions and with atrial electrical remodeling.