Topology Optimization Applied to Electrical Impedance Tomography

Electrical Impedance Tomography (EIT) is a imaging method that estimates conductivity distribution inside a body (domain). In this method, images are obtained by applying a sequence of low intensity electrical currents, through electrodes positioned around the body. Applications of EIT can be often found in geophysics sciences, non-destructive testing and medical applications. Although in EIT there are serious difficulties in obtaining a high-quality conductivity image its technology is safer and cheaper than other tomography techniques. The EIT deals with an inverse problem in which given the measured voltages on electrodes, it estimates the conductivity distribution by using an image reconstruction algorithm. In this work, Topology Optimization Method is applied as a reconstruction algorithm in EIT to obtain images of a foreign material or faults inside a body. This method combines the Finite Element Method and a Sequential Linear Programming (SLP) algorithm to solve the inverse problem of EIT. The SLP allows us to apply easily some regularization schemes based on included constraints in the topology optimization problem, which consists of finding systematically a material distribution (or conductivity distribution) in the domain that minimizes the difference between measured voltages and voltages calculated by using a computational model. A material model based on SIMP is applied to guarantee the relaxation of this optimization problem. The sensitivity analysis is obtained analytically through adjoint method. The implemented algorithm is applied to estimate conductivity distribution of some 2D and 3D examples by using numerical and experimental data, respectively

Three-dimensional electrical impedance, tomography: A topology optimization approach

Electrical impedance tomography is a technique to estimate the impedance distribution within a domain, based on measurements on its boundary. In other words, given the mathematical model of the domain, its geometry and boundary conditions, a nonlinear inverse problem of estimating the electric impedance distribution can be solved. Several impedance estimation algorithms have been proposed to solve this problem. In this paper, we present a three-dimensional algorithm, based on the topology optimization method, as an alternative. A sequence of linear programming problems, allowing for constraints, is solved utilizing this method. In each iteration, the finite element method provides the electric potential field within the model of the domain. An electrode model is also proposed (thus, increasing the accuracy of the finite element results). The algorithm is tested using numerically simulated data and also experimental data, and absolute resistivity values are obtained. These results, corresponding to phantoms with two different conductive materials, exhibit relatively well-defined boundaries between them, and show that this is a practical and potentially useful technique to be applied to monitor lung aeration, including the possibility of imaging a pneumothorax

New Advances in Topology Optimization

IASS-IACM 2008 Session: New Advances in Topology Optimization -- Session Organizers: Glaucio H. PAULINO (UIUC), Emilio SILVA (University of Sao Paulo) -- Keynote Lecture: "Topology optimization with adaptive mesh refinement" by Eric DE STURLER (Virginia Tech), Glaucio H. PAULINO, Shun WANG (University of Illinois at Urbana-Champaign) -- "Strategies for computational efficiency in continuum structural topology optimization of sparse 3D systems" by Colby C. SWAN , Salam F. RAHMATALLA (University of Iowa) -- "Wachpress elements for topology optimization" by Cameron TALISCHI , Glaucio H. PAULINO, Chau H. LE (University of Illinois at Urbana-Champaign) -- "Topology optimization technique considering both static and dynamic characteristics of the structures" by S. J. LEE , J. E. BAE (Gyeongsang National University) -- Keynote Lecture: "Topology optimization method utilizing iterative solvers with subspace recycling applied to high-resolution electrical impedance tomography" by Luis Augusto Motta MELLO , Emilio Carlos Nelli SILVA (University of Sao Paulo), Eric DE STURLER (Virginia Tech), Glaucio H. PAULINO (University of Illinois at Urbana-Champaign) -- "Topology optimization considering fabrication errors and length scale constraints" by James K. GUEST (Johns Hopkins University) -- "A simple and effective inverse projection scheme for void distribution control in topology optimization" by Glaucio H. PAULINO (University of Illinois at Urbana-Champaign), Sylvia ALMEIDA (Universidade Federal de Goias), Emilio Carlos Nelli SILVA (University of Sao Paulo) -- "Design of dynamic laminate piezoelectric sensors and actuators using topology optimization" by Paulo Henrique NAKASONE , Emilio Carlos Nelli SILVA (University of Sao Paulo

Exílio escravista: Hercule Florence e as fronteiras do açúcar e do café no Oeste paulista (1830-1879)

RESUMO O artigo investiga a trajetória do artista e inventor Antonie Hercule Romuald Florence (1804-1879) na sociedade escravista brasileira do século XIX, procurando examinar os fundamentos do "sentimento de exílio" que marcou sua longa vivência no Oeste de São Paulo. Na primeira parte, trato Florence como um observador das paisagens escravistas do açúcar e do café. A série de desenhos e aquarelas que compôs sobre a fazenda Ibicaba e o engenho da Cachoeira nos permite observar como ele apreendeu os processos concretos de transformação agrária e ambiental da fronteira escravista de São Paulo. Na segunda parte, analiso a conversão de Florence em cafeicultor escravista, momento em ele assumiu por razões familiares a gestão de uma propriedade cafeeira com trinta escravos no município de Campinas

Mediatization of a (non-) preservation: the relations of society, journalism and the internet on the demolition of Monroe Palace

Tem sido uma constante no campo patrimonial a exortação de que as políticas do patrimônio precisam se aproximar dos anseios preservacionistas da população. Este artigo procura discutir essa máxima, analisando as razões para a demanda pró-preservação de não especialistas do Palácio Monroe, obra de arquitetura erigida pelo governo brasileiro em 1904, nos EUA, remontada no Brasil, em 1906, e demolida em 1976. Como forma de entender a percepção da sociedade sobre o patrimônio, procura-se mostrar como o processo de demolição do Monroe mobilizou a sociedade carioca. O objetivo é compreender a produção de memória e da história do Rio por pessoas que não pertencem às agências oficiais do patrimônio e que podem, como resultado, permitir que o circuito social da arquitetura seja incorporado às discussões do campo do patrimônio.Many scholars have pointed that the preservation policies should contemplate the society desires. This article discusses this maximum analyzing the reasons that produced demands from non-specialists about the preservation of the Monroe Palace. This building, that originally was built by the Brazilian government in 1904, in the US, was reassembled in Rio de Janeiro in 1906 and demolished in 1976. In order to understand the perception of society about this building, this paper seeks to show how the Monroe’s demolition mobilized Rio society. Taking this episode about the (non-) preservation of this architecture, we developed some reflections on the role of the journalism, blogs and websites, framed by one methodological preoccupation. The goal is to comprehend the production of the Rio’s memory and history by people that do not belong to official agencies of heritage in that city and, as result, to allow the discussion about the social circuit of the architecture within the heritage field

Adherence to treatment in allergic rhinitis using mobile technology. The MASK Study

Background: Mobile technology may help to better understand the adherence to treatment. MASK-rhinitis (Mobile Airways Sentinel NetworK for allergic rhinitis) is a patient-centred ICT system. A mobile phone app (the Allergy Diary) central to MASK is available in 22 countries. Objectives: To assess the adherence to treatment in allergic rhinitis patients using the Allergy Diary App. Methods: An observational cross-sectional study was carried out on all users who filled in the Allergy Diary from 1 January 2016 to 1 August 2017. Secondary adherence was assessed by using the modified Medication Possession Ratio (MPR) and the Proportion of days covered (PDC) approach. Results: A total of 12 143 users were registered. A total of 6 949 users reported at least one VAS data recording. Among them, 1 887 users reported ≥7 VAS data. About 1 195 subjects were included in the analysis of adherence. One hundred and thirty-six (11.28%) users were adherent (MPR ≥70% and PDC ≤1.25), 51 (4.23%) were partly adherent (MPR ≥70% and PDC = 1.50) and 176 (14.60%) were switchers. On the other hand, 832 (69.05%) users were non-adherent to medications (MPR <70%). Of those, the largest group was non-adherent to medications and the time interval was increased in 442 (36.68%) users. Conclusion and clinical relevance: Adherence to treatment is low. The relative efficacy of continuous vs on-demand treatment for allergic rhinitis symptoms is still a matter of debate. This study shows an approach for measuring retrospective adherence based on a mobile app. This also represents a novel approach for analysing medication-taking behaviour in a real-world setting

Diminishing benefits of urban living for children and adolescents’ growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified