Patient-specific outcome simulation after surgical correction of Pectus Excavatum: a preliminary study

Although minimally invasive Nuss procedure is frequently performed to correct Pectus Excavatum, the successful aesthetical outcome is not always ensured. Using the computed tomography (CT) data of six patients, high-quality surfaces of the anterior chest wall were generated, alongside with a personalized corrective-bar. Through finite element method (FEM), replicating the surgical procedure, a simulation of the anterior chest wall correction was conducted. The assessment of this methodology was verified by comparing the metrics from the real meshes (3D scanned before and after surgery) and simulated meshes (obtained before and after FEM). Results show a mean difference of 2.85 +/- 5.77 mm on the point of maximum correction between simulated and real outcomes. No statistical differences were found (p = 0.281). High aesthetical similarity was observed concerning simulated and real outcomes. The proposed methodology presents a patient-specific simulation that may be used to plan, predict and improve the surgical outcome of the Nuss procedure. Further studies should continue to improve the presented methodology.This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the projects POCI-01-0145-FEDER-007038; NORTE-01-0145-FEDER-000013; and NORTE-01-0145-FEDER-024300, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). Joao Gomes-Fonseca was funded by FCT under the Ph.D. grant PD/BDE/113597/2015

Towards a CAD-based automatic procedure for patient specific cutting guides to assist sternal osteotomies in pectus arcuatum surgical correction

Abstract Pectus Arcuatum, a rare congenital chest wall deformity, is characterized by the protrusion and early ossification of sternal angle thus configuring as a mixed form of excavatum and carinatum features. Surgical correction of pectus arcuatum always includes one or more horizontal sternal osteotomies, consisting in performing a V-shaped horizontal cutting of the sternum (resection prism) by means of an oscillating power saw. The angle between the saw and the sternal body in the V-shaped cut is determined according to the peculiarity of the specific sternal arch. The choice of the right angle, decided by the surgeon on the basis of her/his experience, is crucial for a successful intervention. The availability of a patient-specific surgical guide conveying the correct cutting angles can considerably improve the chances of success and, at the same time, reduce the intervention time. The present paper aims to propose a new CAD-based approach to design and produce custom-made surgical guides, manufactured by using additive manufacturing techniques, to assist the sternal osteotomy. Starting from CT images, the procedure allows to determine correct resection prism and to shape the surgical guide accordingly taking into account additive manufacturing capabilities. Virtually tested against three case studies the procedure demonstrated its effectiveness. Highlights Patient-specific surgical guide improves the chances of success in sternal osteotomy. A CAD-based approach to design and produce custom-made surgical guides is proposed. The proposed framework entails both a series of automatic and user-guided tasks

3D Printing Technologies

The family of technologies collectively known as additive manufacturing (AM) technologies, and often called 3D-printing technologies, is rapidly revolutionizing industrial production. AM’s potential to produce intricate and customized parts starting from a digital 3D model makes it one of the main pillars for the forthcoming Industry 4.0. Thanks to its advantages over traditional manufacturing methodologies, AM finds potential applicability in virtually all production fields. As a natural consequence of this, research in this field is primarily focused on the development of novel materials and techniques for 3D printing. This Special Issue of Technologies, titled “3D Printing Technologies”, aims at promoting the latest knowledge in materials, processes, and applications for AM. It is composed of six contributions, authored by influential scientists in the field of advanced 3D printing. The intended audience includes professors, graduate students, researchers, engineers and specialists working in the field of AM

Determinação da grade costal em pacientes com pectus excavatum utilizando técnicas imagiológicas sem radiação

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Eletrónica Médica)Todas as áreas científicas que apoiam e suportam a medicina têm evoluído muito ao longo dos anos. Uma dessas áreas é a Engenharia sendo indispensável para o eficaz e eficiente funcionamento do que hoje conhecemos como Medicina Moderna. A imagem médica, área muito explorada e dependente da Engenharia, tem evoluído muito e atualmente é possível diagnosticar, tratar e melhorar procedimentos, diminuir o erro humano, investigar com melhores práticas e até modelar próteses devido à evolução desta área. Isto tem acontecido quer através do aperfeiçoamento dos equipamentos de aquisição de imagens médicas, como também das técnicas de processamento de imagem usadas. Hoje em dia, a Tomografia Computadorizada (modalidade da imagem médica) é usada como exame de pré-diagnóstico para a correção do pectus excavatum, uma deformidade que ocorre na parede do tórax. Contudo, a Tomografia Computadorizada não é benéfica para os pacientes devido ao seu princípio físico de aquisição se basear em radiação, o que poderá originar a longo prazo problemas de saúde graves. Como a correção do pectus excavatum é cada vez mais uma cirurgia estética, onde o seu principal objetivo é evitar problemas psicológicos e de stress social nas crianças e jovens adolescentes portadores desta deformidade, tem-se questionado a real necessidade do uso da Tomografia Computadorizada. Tendo em consideração a realidade descrita foi objetivo deste trabalho avaliar a possibilidade de reconstruir um plano axial do tórax, contendo a grade costal, a partir de imagens por ultrassons e recorrendo a técnicas de processamento imagem. O intuito desta reconstrução foi eliminar a Tomografia Computadorizada do procedimento de modelação/dobragem automática da prótese cirúrgica para a correção do pectus excavatum. As técnicas e algoritmos de processamento de imagem usados e implementados, para obter um plano axial a partir de várias imagens de ultrassons, basearam-se no realce das imagens através de filtragem, no registo para obter as transformações entre imagens, na segmentação das estruturas ósseas e na reconstrução do plano final a partir dos dados do registo e da segmentação. Os resultados preliminares obtidos, principalmente de imagens de um phantom, demonstraram que é possível fazer reconstruções contendo informações das estruturas presentes no plano adquirido, como também da curvatura do tórax. Imagens obtidas com o phantom submerso em água demonstraram melhores resultados, onde as estruturas estão bem definidas e as dimensões coincidem quando comparadas com a Tomografia Computadorizada. Dados in vivo, mostraram que é possível reconstruir planos contendo a informação anatómica, no entanto, ainda não foi possível obter a curvatura real do tórax. Porém, o algoritmo de segmentação das estruturas ósseas demonstrou ser capaz de realçar a superfície do osso. Futuramente prevê-se a contínua otimização dos algoritmos, otimização dos parâmetros de aquisição da imagem e utilização de equipamentos externos de apoio à aquisição de imagens.All the scientific areas that support medicine have evolved enormously over the years. One such area is engineering, being indispensable for the effective and efficient functioning of what we know today as modern medicine. The medical imaging, a very explored and dependent area of the engineering, has greatly progressed and nowadays it is possible to diagnose, treat, improve procedures, reduce human error, investigate with best practices and model prosthesis due to developments in this area. This has occurred by improving the imaging equipment as well as the medical image processing techniques. Nowadays, the Computed Tomography (medical image modality) is used as pre-diagnosis examination for the correction of pectus excavatum, a deformity that occurs in the chest wall. However, Computed Tomography is not beneficial for patients because its physical principle of acquisition is based on radiation, which may lead to long-term serious health problems. As the correction of pectus excavatum is more a cosmetic surgery, where its main objective is to avoid psychological problems and social stress in children and young adolescents with this deformity, it has been questioned the real need for the use of Computed Tomography. Taking into account the described reality, the objective of this study was to evaluate the possibility to reconstruct an axial plane of the chest with the rib cage using ultrasound images and image processing techniques. The purpose of this reconstruction was to eliminate the Computed Tomography from the procedure of automatic modeling/bending the prosthesis for the surgical correction of pectus excavatum. The image processing techniques and algorithms used and implemented to obtain an axial plane, using several ultrasound images, were based in image enhancement using filtering techniques, in registration to obtain the transformations between images, the segmentation of bone structures and the reconstruction of the final plan from the data of registration and segmentation. The preliminary results, mostly from a phantom, showed that it is possible to make reconstructions containing the information of the structures present in the scanned plan, as well as the curvature of the chest. Acquired images with the phantom submerged in water exhibited better results, where the structures are well defined and the dimensions match when compared with Computed Tomography. In vivo data indicated that it is possible to reconstruct planes containing the anatomical information, however, still cannot get the actual curvature of the chest. The segmentation algorithm of bone structures has been shown to enhance the surface of the bone. Hereafter, it is anticipated the continuous optimization of algorithms, the optimization of image acquisition parameters and the use of external equipment to support the image acquisition.Fundação para a Ciência e a Tecnologia (FCT

Computational modelling of the scoliotic spine: A literature review

Scoliosis is a deformity of the spine that in severe cases requires surgical treatment. There is still disagreement among clinicians as to what the aim of such treatment is as well as the optimal surgical technique. Numerical models can aid clinical decision-making by estimating the outcome of a given surgical intervention. This paper provided some background information on the modelling of the healthy spine and a review of the literature on scoliotic spine models, their validation, and their application. An overview of the methods and techniques used to construct scoliotic finite element and multibody models was given as well as the boundary conditions used in the simulations. The current limitations of the models were discussed as well as how such limitations are addressed in non-scoliotic spine models. Finally, future directions for the numerical modelling of scoliosis were addressed

Computational modelling of the scoliotic spine: A literature review

open4siScoliosis is a deformity of the spine that in severe cases requires surgical treatment. There is still disagreement among clinicians as to what the aim of such treatment is as well as the optimal surgical technique. Numerical models can aid clinical decision-making by estimating the outcome of a given surgical intervention. This paper provided some background information on the modelling of the healthy spine and a review of the literature on scoliotic spine models, their validation, and their application. An overview of the methods and techniques used to construct scoliotic finite element and multibody models was given as well as the boundary conditions used in the simulations. The current limitations of the models were discussed as well as how such limitations are addressed in non-scoliotic spine models. Finally, future directions for the numerical modelling of scoliosis were addressed.Marco Viceconti and Giorgio Davico were supported by the EU funded project Mobilise-D. The charity Reuse-WithLove is gratefully acknowledged for the financial support to this research.openGould, Samuele L; Cristofolini, Luca; Davico, Giorgio; Viceconti, MarcoGould, Samuele L; Cristofolini, Luca; Davico, Giorgio; Viceconti, Marc

Automatic 3D extraction of pleural plaques and diffuse pleural thickening from lung MDCT images

Pleural plaques (PPs) and diffuse pleural thickening (DPT) are very common asbestos related pleural diseases (ARPD). They are currently identified non-invasively using medical imaging techniques. A fully automatic algorithm for 3D detection of calcified pleura in the diaphragmatic area and thickened pleura on the costal surfaces from multi detector computed tomography (MDCT) images has been developed and tested. The algorithm for detecting diaphragmatic pleura includes estimation of the diaphragm top surface in 3D and identifying those voxels at a certain vertical distance from the estimated diaphragm, and with intensities close to that of bone, as calcified pleura. The algorithm for detecting thickened pleura on the costal surfaces includes: estimation of the pleural costal surface in 3D, estimation of the centrelines of ribs and costal cartilages and the surfaces that they lie on, calculating the mean distance between the two surfaces, and identifying any space between the two surfaces whose distance exceeds the mean distance as thickened pleura. The accuracy and performance of the proposed algorithm was tested on 20 MDCT datasets from patients diagnosed with existing PPs and/or DPT and the results were compared against the ground truth provided by an experienced radiologist. Several metrics were employed and evaluations indicate high performance of both calcified pleura detection in the diaphragmatic area and thickened pleura on the costal surfaces. This work has made significant contributions to both medical image analysis and medicine. For the first time in medical image analysis, the approach uses other stable organs such as the ribs and costal cartilage, besides the lungs themselves, for referencing and landmarking in 3D. It also estimates fat thickness between the rib surface and pleura (which is usually very thin) and excludes it from the detected areas, when identifying the thickened pleura. It also distinguishes the calcified pleura attached to the rib(s), separates them in 3D and detects calcified pleura on the lung diaphragmatic surfaces. The key contribution to medicine is effective detection of pleural thickening of any size and recognition of any changes, however small. This could have a significant impact on managing patient risks

Proceedings, MSVSCC 2018

Proceedings of the 12th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 19, 2018 at VMASC in Suffolk, Virginia. 155 pp

Proceedings, MSVSCC 2015

The Virginia Modeling, Analysis and Simulation Center (VMASC) of Old Dominion University hosted the 2015 Modeling, Simulation, & Visualization Student capstone Conference on April 16th. The Capstone Conference features students in Modeling and Simulation, undergraduates and graduate degree programs, and fields from many colleges and/or universities. Students present their research to an audience of fellow students, faculty, judges, and other distinguished guests. For the students, these presentations afford them the opportunity to impart their innovative research to members of the M&S community from academic, industry, and government backgrounds. Also participating in the conference are faculty and judges who have volunteered their time to impart direct support to their students’ research, facilitate the various conference tracks, serve as judges for each of the tracks, and provide overall assistance to this conference. 2015 marks the ninth year of the VMASC Capstone Conference for Modeling, Simulation and Visualization. This year our conference attracted a number of fine student written papers and presentations, resulting in a total of 51 research works that were presented. This year’s conference had record attendance thanks to the support from the various different departments at Old Dominion University, other local Universities, and the United States Military Academy, at West Point. We greatly appreciated all of the work and energy that has gone into this year’s conference, it truly was a highly collaborative effort that has resulted in a very successful symposium for the M&S community and all of those involved. Below you will find a brief summary of the best papers and best presentations with some simple statistics of the overall conference contribution. Followed by that is a table of contents that breaks down by conference track category with a copy of each included body of work. Thank you again for your time and your contribution as this conference is designed to continuously evolve and adapt to better suit the authors and M&S supporters. Dr.Yuzhong Shen Graduate Program Director, MSVE Capstone Conference Chair John ShullGraduate Student, MSVE Capstone Conference Student Chai