Simple and promising paper-based electrochemical platform for serological detection of American tegumentary leishmaniasis

BACKGROUND American tegumentary leishmaniasis (ATL) is an endemic neglected tropical disease (NTD), its conventional treatment is toxic, slow, and invasive. Rapid diagnosis is crucial for the clinical management of suspected patients, so the development and use of low-cost, miniaturised and portable devices could be the key. OBJECTIVES This work aimed to develop a simple paper-based electrochemical platform for the serological detection of ATL. METHODS Platform was fabricated in Whatman N°1 paper, contains a hydrophobic zone generated by wax printing, two pencil graphite electrodes, and uses specific crude extracts (CA) antigens for ATL immuno-determination. The platform performance was analysed by measuring the relative impedance change for different antigen-antibody combinations. Then, 10 serum human samples previously diagnosed by the gold standard (five positive ATL cases and five non-ATL cases) were evaluated. FINDINGS The platform presented a linear response for the charge transfer resistance (ΔRct) and the interface reactance (ΔXc). Also, optimal working conditions were established (1/60 serum dilution and 180 µg/mL CA concentration). Then, the platform permits to distinguish between ATL and non-ATL (p < 0.05) human serum samples. MAIN CONCLUSIONS Our platform could allow the diagnosis, management, and monitoring of leishmaniasis while being an extremely simple and environmentally friendly technology.

Evaluation of Clinical Efficacy of Modified Houpo Dahuangtang in Moderate and Severe ARDS Patients Based on Electrical Impedance Tomography / 中国实验方剂学杂志

ObjectiveTo evaluate the clinical efficacy of modified Houpo Dahuangtang in moderate and severe acute respiratory distress syndrome （ARDS） patients with phlegm-heat accumulation，and monitor the pulmonary ventilation changes of patients before and after treatment by electrical impedance tomography（EIT）. MethodThe 62 cases of moderate and severe ARDS patients with phlegm-heat accumulation who required mechanical ventilation in the department of intensive care unit （ICU） in Chongqing Hospital of Traditional Chinese Medicine from September 2021 to June 2022 were selected，and divided into an experimental group（31 cases）and a control group（31 cases）using a random number table. On the basis of regular Western medicine treatment，the experimental group received modified Houpo Dahuangtang and the control group received warm water by a nasogastric tube for seven days. The changes in the clinical efficacy of traditional Chinese medicine（TCM），the oxygenation index［arterial oxygen partial pressure （PaO2）/fractional inspired oxygen（FiO2），P/F］，lactic acid（Lac），acute physiology and chronic health evaluation Ⅱ（APACHE Ⅱ） score，compliance，plateau pressure，gas distribution parameters monitored by EIT（Z1，Z2，Z3 and Z4），inflammatory factors［interleukin-6 （IL-6），IL-10， tumor necrosis factor-α （TNF-α） and C-reactive protein （CRP）］ of both groups before and after treatment were recorded. Besides， the mechanical ventilation time， length of stay in ICU， 28-day mortality and incidence of adverse reactions（delirium，abdominal pain and diarrhea）in the two groups were also observed. ResultThere was no significant difference in the baseline indexes of patients in the two groups，and thus the two groups were comparable. After treatment for one week， the total effective rate for TCM syndromes in the experimental group was 90.30%（28/31）， higher than the 67.74%（21/31）in the control group（Z=-2.415，P<0.05）.Compared with the same group before treatment， the plateau pressure and Lac decreased （P<0.01）and the compliance and P/F increased （P<0.01） in experimental group， while the Lac decreased （P<0.05）and the P/F increased （P<0.05）， and the compliance and plateau pressure did not change significantly in the control group. After treatment，the plateau pressure and inflammatory factors in the experimental group were lower than those in the control group（P<0.05）， but the compliance and P/F in the experimental group were higher than those in the control group（P<0.05）， and the gas distribution parameters Z1，Z2，Z3，Z4，Z1+Z2，and Z3+Z4 monitored by EIT in the experimental group were all higher than those in the control group （P<0.05）. There was no significant difference in mechanical ventilation time， ICU hospitalization time， 28-day mortality， delirium， abdominal pain， diarrhea and other adverse reactions between the two groups. ConclusionModified Houpo Dahuangtang can significantly improve the P/F，pulmonary ventilation in gravity-dependent regions and pulmonary compliance，reduce the release of inflammatory factors in moderate and severe ARDS patients. Compared with conventional methods，EIT can timely monitor the pulmonary ventilation changes in ARDS patients，which suggests its clinical feasibility.

Avaliação Cardiodinâmica Não Invasiva por Cardiografia de Impedância durante o Teste de Caminhada de Seis Minutos em Pacientes com Insuficiência Cardíaca / Non-Invasive Assessment of Cardiodynamics by Impedance Cardiography during the Six-Minute Walk Test in Patients with Heart Failure

Resumo Fundamento O Teste de Caminhada de seis Minutos (TC6M) é comumente usado para avaliar pacientes com insuficiência cardíaca. No entanto, vários fatores clínicos podem influenciar a distância percorrida pelos pacientes no teste. A cardiografia de impedância (CI) na avaliação morfológica é uma ferramenta útil para avaliar a hemodinâmica cardíaca de maneira não invasiva. Objetivo Este estudo teve como objetivo comparar as respostas de aceleração e desaceleração do Débito Cardíaco (DC), da Frequência Cardíaca (FC), e do Volume Sistólico (VS) ao TC6M de indivíduos com insuficiência cardíaca e fração de ejeção reduzida (ICFEr) com as de controles sadios. Métodos Este é um estudo transversal observacional. O DC, a FC, o VS e o Índice Cardíaco (IC) foram avaliados antes, durante e após o TC6M por CI. O nível de significância adotado na análise estatística foi 5%. Resultados Foram incluídos 27 participantes (13 com ICFEr e 14 controles sadios). A aceleração do DC e da FC foi significativamente diferente entre os grupos (p<0,01 e p=0,039, respectivamente). Encontramos diferenças significativas no VS, no DC e no IC entre os grupos (p<0,01). A regressão linear mostrou uma contribuição deficiente do VS à mudança no DC no grupo com ICFEr (22,9% versus 57,4%). Conclusão O principal resultado deste estudo foi o fato de que indivíduos com ICFEr apresentaram valores mais baixos de aceleração do DC e da FC durante o teste de exercício submáximo em comparação a controles sadios. Isso pode indicar um desequilíbrio na resposta autonômica ao exercício nessa condição.

Abstract Background The six-minute walk test (6MWT) is commonly used to evaluate heart failure (HF) patients. However, several clinical factors can influence the distance walked in the test. Signal-morphology impedance cardiography (SM-ICG) is a useful tool to noninvasively assess hemodynamics. Objective This study aimed to compare cardiac output (CO), heart rate (HR), and stroke volume (SV) acceleration and deceleration responses to 6MWT in individuals with HF and reduced ejection fraction (HFrEF) and healthy controls. Methods This is a cross-sectional observational study. CO, HR, SV and cardiac index (CI) were evaluated before, during, and after the 6MWT assessed by SM-ICG. The level of significance adopted in the statistical analysis was 5%. Results Twenty-seven participants were included (13 HFrEF and 14 healthy controls). CO and HR acceleration significantly differed between groups (p<0.01; p=0.039, respectively). We found significant differences in SV, CO and CI between groups (p<0.01). Linear regression showed an impaired SV contribution to CO change in HFrEF group (22.9% versus 57.4%). Conclusion The main finding of the study was that individuals with HFrEF showed lower CO and HR acceleration values during the submaximal exercise test compared to healthy controls. This may indicate an imbalance in the autonomic response to exercise in this condition.

Desarrollo de un modelo por inteligencia artificial con hemodinamia no invasiva para predecir preeclampsia en embarazos de alto riesgo / Artificial Intelligence Modeling with Non-Invasive Hemodynamics to Predict Preeclampsia in High-Risk Pregnancy

RESUMEN Introducción: la preeclampsia (PE) es la principal causa de morbimortalidad materno-fetal en nuestro país. Alteraciones hemodinámicas precoces durante el embarazo podrían predecir la evolución a PE. El machine learning (ML) permite el hallazgo de patrones ocultos que podrían detectar precozmente el desarrollo de PE. Objetivos: desarrollar un árbol de clasificación con variables de hemodinamia no invasiva para predecir precozmente desarrollo de PE. Material y métodos: estudio observacional prospectivo con embarazadas de alto riesgo (n=1155) derivadas del servicio de Obstetricia desde enero 2016 a octubre 2022 para el muestreo de entrenamiento por ML con árbol de clasificación j48. Se seleccionaron 112 embarazadas entre semanas 10 a 16, sin tratamiento farmacológico y que completaron el seguimiento con el término de su embarazo con evento final combinado (PE): preeclampsia, eclampsia y síndrome HELLP. Se evaluaron simultáneamente con cardiografía de impedancia y velocidad de onda del pulso y con monitoreo ambulatorio de presión arterial de 24 hs (MAPA). Resultados: presentaron PE 17 pacientes (15,18%). Se generó un árbol de clasificación predictivo con las siguientes variables: índice de complacencia arterial (ICA), índice cardíaco (IC), índice de trabajo sistólico (ITS), cociente de tiempos eyectivos (CTE), índice de Heather (IH). Se clasificaron correctamente el 93,75%; coeficiente Kappa 0,70, valor predictivo positivo (VPP) 0,94 y negativo (VPN) 0,35. Precisión 0,94, área bajo la curva ROC 0,93. Conclusión: las variables ICA, IC, ITS, CTE e IH predijeron en nuestra muestra el desarrollo de PE con excelente discriminación y precisión, de forma precoz, no invasiva, segura y con bajo costo.

ABSTRACT Background: Preeclampsia (PE) is the main cause of maternal-fetal morbidity and mortality in our country. Early hemodynamic changes during pregnancy could predict progression to PE. Machine learning (ML) enables the discovery of hidden patterns that could early detect PE development. Objectives: The aim of this study was to build a classification tree with non-invasive hemodynamic variables for the early prediction of PE occurrence. Results: Seventeen patients (15.18%) presented PE. A predictive classification tree was generated with arterial compliance index (ACI), cardiac index (CI), cardiac work index (CWI), ejective time ratio (ETR), and Heather index (HI). A total of 93.75% patients were correctly classified (Kappa 0.70, positive predictive value 0.94 and negative predictive value 0.35; accuracy 0.94, and area under the ROC curve 0.93). Conclusion: ACI, CI, CWI, ETR and HI variables predicted the early development of PE in our sample with excellent discrimination and accuracy, non-invasively, safely and at low cost.

Monitorización avanzada durante la desvinculación de la ventilación mecánica invasiva en el trasplante unipulmonar / Advanced monitoring during weaning of invasive me chanical ventilation in single-lung transplantation

Resumen El trasplante de pulmón bilateral es el tratamiento de las enfermedades pulmonares en su etapa terminal. Sin embargo, a veces se realiza el trasplante de un solo pulmón. La técnica no está exenta de complicaciones como la hiperinsuflación aguda del pulmón nativo y cambios en el diafragma, predisponiendo a atelectasias e insuficiencia respiratoria que pueden derivar en resul tados negativos. Por lo tanto, las pruebas de respiración espontánea pueden fallar y retrasar el proceso de des vinculación de la ventilación mecánica. La combinación de herramientas de monitorización avanzadas, como la tomografía por impedancia eléctrica y la ecografía, para diagnosticar la causa de este fallo, reconociendo y cuantificando la distribución del volumen pulmonar y su comportamiento dinámico, podría ser crucial para mejorar los resultados. Presentamos el caso de un paciente con trasplante unipulmonar y ventilación prolongada que falla en repetidas ocasiones durante la desvinculación de la ventilación mecánica, donde utilizamos herramientas de monitoreo avanzado para detectar la causa de la falla.

Abstract Bilateral lung transplantation is the treatment of end-stage lung diseases. However, sometimes a single lung transplant is performed. The technique is not exempt from complications such as acute hyperinfla tion of the native lung and changes in the diaphragm, predisposing to atelectasis and respiratory failure that can lead to negative results. Therefore, spontaneous breathing trials may fail and delay the weaning process. The combination of advanced monitoring tools, such as electrical impedance tomography and ultrasonography, to diagnose the cause of this failure, recognizing and quantifying the distribution of lung volume and its dynamic behavior could be crucial to improve outcomes. We present the case of a patient with a one-lung transplant and prolonged mechanical ventilation who, after presenting successive failures in the weaning pro cess, underwent advanced monitoring in order to find the causes of the failure.

Associação entre força de preensão manual e ângulo de fase em idosos da Estratégia Saúde da Família: um estudo transversal / Association between handgrip strength and phase angle in older adults from the Family Health Strategy: a cross-sectional study

Introdução: a Força de Preensão Manual (FPM) é um indicador de saúde e funcionalidade do idoso, que diminui com o passar do tempo, impactada por aspectos como mudanças na composição corporal. Objetivo: investigar a associação entre o Ângulo de Fase Padronizado (AFP) e FPM em idosos comunitários da Atenção Primária à Saúde (APS). Metodologia: estudo transversal, com pessoas de 60 anos ou mais, atendidos na APS. A variável dependente foi a FPM medida com dinamômetro e a independente principal foi o AFP com base no sexo e faixa etária, calculado a partir do ângulo de fase obtido pela bioimpedância. Foi realizada a regressão logística com entrada por bloco, sendo incluídas no modelo as variáveis que apresentaram associação com nível crítico menor do que 10%. Resultados: dos 296 indivíduos avaliados, 28,0% exibiram baixa FPM e 15,9% apresentaram AFP < ­ 1,65°. As variáveis inseridas no modelo final de regressão logística, juntamente com o AFP, foram sexo, faixa etária, Índice de Massa Corporal (IMC) e Circunferência da Panturrilha (CP). A análise mostrou que o AFP < ­ 1,65° aumenta a chance do idoso apresentar baixa FPM, tanto na análise sem ajuste (OR = 2,71; IC 95% 1,43-5,15), quanto no modelo final (OR = 2,35; IC 95% 1,14-4,87). Conclusão: o AFP mostrou-se associado à FPM, independentemente da interação com sexo, faixa etária, IMC e CP. A sua utilização pode contribuir na avaliação de idosos, especialmente quando a aferição da FPM não for possível.

Introduction: Handgrip Strength (HGS) is an indicator of health and functionality of the older adults, which decreases over time, impacted by aspects including changes in body composition. Objective: to investigate the association between the Standardized Phase Angle (SPA ) and HGS in community-dwelling older adults in Primary Health Care (PHC). Methodology: cross-sectional study, with people aged 60 or over, assisted in the PHC. The dependent variable was the HGS measured using a dynamometer. The main independent variable was the SPA based on gender and age range, calculated from the phase angle obtained by bioimpedance. Block-by-block logistic regression was performed, including variables that were associated with a critical level lower than 10% in the model. Results: of the 296 individuals assessed, 28.0% had low HGS and 15.9% had SPA < ­ 1.65°. The variables inserted in the final logistic regression model, together with the SPA , were gender, age group, Body Mass Index (BMI) and Calf Circumference (CC). The analysis showed that SPA < ­ 1.65° increases the chance of the older adults having low HGS, both in the unadjusted analysis (OR = 2.71; 95% CI 1.43-5.15) and in the final model (OR = 2.35; 95%CI 1.14-4.87). Conclusion: the SPA was associated with HGS, regardless of the interaction with sex, age group, BMI and CC. Its use can contribute to the evaluation of the older adults, especially when HGS measurement is not possible.

Combined multi-channel intraluminal impedance measurement and pHmetry in the detection of gastroesophageal reflux disease in children with cystic fibrosis

Abstract Objective To assess the prevalence of GERD exclusively by means of multichannel intraluminal impedanciometry associated with pH monitoring (MIIpH) and compare it with respiratory symptoms in children with CF. To compare MIIpH with pHmetry alone to perform GERD diagnosis. Methods An analytical cross-sectional study was conducted with children diagnosed with CF who underwent MIIpH. Clinical and laboratory markers, including respiratory and digestive symptoms, were used for comparative analyses. High-resolution chest computed tomography was performed on patients with symptoms of chronic lung disease. Severity was classified according to the Bhalla score. Results A total of 29 children < 10 yo (18 girls) were evaluated; 19 of whom with physiological GER and 10 with GERD. Of the children with GERD, seven had predominantly acid GER, two acid+non-acid GER, and one non-acid GER. Three patients had GERD diagnosed only by MIIpH. Bhalla scores ranged from seven to 17.75 with no significant relationship with GERD. The number of pulmonary exacerbations was associated with a decrease in esophageal clearance regardless of the position in pHmetry and MIIpH. Conclusions The prevalence of GERD was 34% in children with CF. There was no association between respiratory disease severity and GER types. MIIpH detected 30% more patients with GERD than pHmetry.

Association between phase angle of bioelectrical impedance analysis and nutritional parameters in older adults

INTRODUCTION: Phase angle (PhA) is a Bioelectrical impedance analysis (BIA) parameter representing an indicator of cellular health and has been suggested as a biomarker of nutritional status. OBJECTIVE: To evaluate the association between PhA and nutritional parameters in older adults. METHODS: A cross-sectional study was conducted with community-dwelling older adults. Body mass index (BMI), arm muscle circumference (AMC), calf circumference (CC), body fat percentage (BF%), appendicular skeletal muscle mass (ASMM), serum albumin, mini-nutritional assessment (MNA), and PhA were assessed. Kolmogorov­Smirnov test, Spearman's correlation coefficient, chi-square test, and Poisson regression models were performed. RESULTS: 144 participants were included in the study, and most of them were female, aged ≥80 years, and underweight. Most older adults with lower PhA were women, aged range 80­89 years, and with reduced ASMM (p<0.05). PhA presented a significant correlation with age (r=­0.417; p<0.001), ASMM (r=0.427; p<0.001), AMC (r=0.195; p=0.019) and BF% (r=­0.223; p=0.007). Older adults with lower PhA present reduced ASMM (PR: 1.25; 95%CI: 1.04­1.50), and hypoalbuminemia (PR: 1.50; 95%CI: 1.11­2.03). CONCLUSION: PhA is related to commonly nutritional indicators used in clinical practice and could be an important biomarker of muscle mass reserves in community-living older adults of both sexes.

Role of machine learning techniques in classification of peripheral pulse morphology

Recording of peripheral pulse serves as a very important and essential non-invasive tool used widely by doctors for the diagnosis of various diseases. The morphology of pulse is seen to vary as a function of time in a given individual and also from individual to individual. There are many variations in morphological patterns of peripheral pulse in different disease conditions, which lead to difficulty in accurate diagnosis. The peripheral pulse waveforms are extracted from radial arteries as time series data using a peripheral pulse analyzer which is designed on the principle of impedance plethysmography. It was first introduced by Nyober in the mid-nineteen hundreds and ameliorated further by Kubicek. It involves the recording of the instantaneous blood volume by the measurement of electrical impedance as a function of time. Therefore, the study of peripheral pulse morphology has gained much attention in the past few years among researchers. Physiological variability is one of the recent investigations added during the last two decades for the objective assessment of autonomic function and the assessment of prognosis in severe sicknesses namely myocardial infarction, diabetic neuropathy, etc. In addition to heart rate variability studied worldwide, few researchers have studied blood pressure variability and peripheral blood flow variability. In this computer era, artificial intelligence and machine learning techniques have become more important day-by- day, and different types of algorithms were used for the identification of hidden patterns from plethysmographic observations on the radial pulse such as support vector machine as well as crisp and fuzzy clustering. Eight patterns were classified with a yield of 80%–90% and helped with the diagnosis of disorders such as myocardial infarction, pulmonary tuberculosis, coronary artery disorders, cirrhosis of the liver, and bronchial asthma. This paper briefly describes the use of machine learning techniques for the classification of peripheral pulse morphologies.

Agreement and reproducibility of a portable electrical impedance myography device for body fat percentage estimation in normal weight men and women / Concordância e reprodutibilidade de um dispositivo portátil de miografia por impedância elétrica para estimativa do percentual de gordura corporal em homens e mulheres com peso normal

Abstract The aim of this study was to investigate the agreement and reproducibility of a portable electrical impedance myography device (EIM - SKULPT®) for body fat percentage (BF%) estimation in young adults. Sixty young adults volunteered for the study (women, n=30, 25.0±7.7 years; 21.5±1.9 kg/m2; and men, n=30, 21.6±6.3 years; 22.5±1.8 kg/m2). Participants underwent air displacement plethysmography (ADP) and EIM measurements for agreement analysis. EIM was performed three times on the same day for the within-day reproducibility analysis. Seven days later, 37 participants repeated the EIM measurements for the between-days reproducibility analysis. Comparisons of EIM and ADP methods, and EIM repeated measurements were performed with the paired T-test or one-way ANOVA repeated measures, the Bland-Altman plot, and simple linear regressions. BF% was higher (p<0.05) when estimated by EIM (19.91 ± 5.70 for men, and 30.77 ± 5.89 for women) compared to ADP (15.28 ± 5.66 for men, and 27.31 ± 5.98 for women). The Bland-Altman analysis presented a bias of 4.4% (95%CI=-3.4-12.2) and linear regression presented an R2=0.78. For between-days reproducibility, EIM means did not differ (25.33±7.69 and 24.94±8.30, p=0.890). Thus, while the EIM device exhibited high reproducibility of BF% estimates, caution should be exercised when comparing the results with other techniques for measuring BF%. The EIM device overestimated BF% compared to ADP. However, the EIM measurements presented very good within-day and between-days reproducibility and, thus, the EIM device can be used for longitudinal monitoring of BF%.

Resumo O objetivo deste estudo foi investigar a concordância e a reprodutibilidade de um aparelho portátil de miografia por impedância elétrica (EIM - SKULPT®) para estimativa do percentual de gordura corporal (GC%) em adultos jovens. Sessenta adultos jovens foram voluntários para o estudo (mulheres, n=30, 25,0±7,7 anos; 21,5±1,9 kg/m2; e homens, n=30, 21,6±6,3 anos; 22,5±1,8 kg/m2). Os participantes fizeram medições de pletismografia de deslocamento de ar (ADP) e EIM para análise de concordância. A EIM foi realizada três vezes no mesmo dia para a análise de reprodutibilidade dentro do dia. Sete dias depois, 37 participantes repetiram as medições do EIM para a análise de reprodutibilidade entre dias. As comparações dos métodos EIM e ADP e medições repetidas do EIM foram realizadas com o teste T pareado ou medidas repetidas ANOVA de uma via, o gráfico de Bland-Altman e regressões lineares simples. O %GC foi maior (p<0,05) quando estimado pelo EIM (19,91 ± 5,70 para homens e 30,77 ± 5,89 para mulheres) em relação ao ADP (15,28 ± 5,66 para homens e 27,31 ± 5,98 para mulheres). A análise de Bland-Altman apresentou viés de 4,4% (IC95%=-3,4-12,2) e a regressão linear apresentou R2=0,78. Para a reprodutibilidade entre dias, as médias do EIM não diferiram (25,33±7,69 e 24,94±8,30, p=0,890). Assim, enquanto o dispositivo EIM exibiu alta reprodutibilidade das estimativas de %GC, deve-se ter cautela ao comparar os resultados com outras técnicas para medir %GC. O dispositivo EIM superestimou %GC em comparação com ADP. No entanto, as medidas de EIM apresentaram reprodutibilidade intradia e entre dias muito boa e, portanto, o dispositivo de EIM pode ser usado para monitoramento longitudinal de %GC.

Changes in body composition of burn patients during the phases of response to trauma / Alterações na composição corporal de pacientes queimados durante as fases de resposta ao trauma / Cambios en la composición corporal de pacientes quemados durante las fases de respuesta al trauma

ABSTRACT Objective: To assess the changes in body composition of burn patients through electrical bioimpedance in the phases of response to trauma. Methods: a longitudinal observational study, carried out from October 2019 to March 2020. Sociodemographic, clinical, epidemiological, anthropometric and body composition data were collected. Statistical analysis was performed with SPSS, considering a significance of 5%. The comparison between variables was performed using the paired Student's t test. Results: the sample consisted of 58 adult burn patients, with a mean age of 38.2±12.5 years. The mean body surface area (BSA) with burns was 10.8±7.3%. Nutritional assessment demonstrated a depletion of body weight, Body Mass Index, fat-free mass and muscle mass in the phases of response to trauma (p<0.005). Conclusion: metabolic alterations in the different phases of the metabolic response to trauma led to a depletion of the nutritional status of burn patients of both sexes during hospitalization.

RESUMO Objetivo: avaliar as alterações na composição corporal de pacientes queimados por meio da bioimpedância elétrica nas fases de resposta ao trauma. Métodos: estudo observacional longitudinal, realizado de outubro de 2019 a março de 2020. Foram coletados dados sociodemográficos, clínicos, epidemiológicos, antropométricos e de composição corporal. A análise estatística foi realizada com o SPSS, considerando significância de 5%. Comparação entre as variáveis foi realizada por meio do teste t de Student pareado. Resultados: a amostra foi composta por 58 pacientes adultos queimados, com média de 38,2±12,5 anos. A média da área de superfície corporal (ASC) com queimaduras foi de 10,8±7,3%. A avaliação nutricional demonstrou depleção do peso corporal, índice de massa corporal, massa magra e massa muscular nas fases de resposta ao trauma (p<0,005). Conclusão: alterações metabólicas nas diferentes fases da resposta metabólica ao trauma levaram a depleção do estado nutricional de pacientes queimados de ambos os sexos durante a internação.

RESUMEN Objetivo: evaluar alteraciones en la composición corporal de pacientes quemados mediante bioimpedancia eléctrica en las fases de respuesta al trauma. Métodos: estudio observacional longitudinal, realizado de octubre de 2019 a marzo de 2020. Se recogieron datos sociodemográficos, clínicos, epidemiológicos, antropométricos y de composición corporal. El análisis estadístico se realizó mediante SPSS, considerando una significancia del 5%. La comparación entre variables se realizó mediante la prueba de la t de Student pareada. Resultados: la muestra estuvo compuesta por 58 pacientes adultos quemados, con una edad media de 38,2±12,5 años. El área de superficie corporal media (ASC) con quemaduras fue de 10,8±7,3%. La evaluación nutricional mostró disminución del peso corporal, índice de masa corporal, masa magra y masa muscular en las fases de respuesta al trauma (p<0,005). Conclusión: los cambios metabólicos en las diferentes fases de la respuesta metabólica al trauma llevaron a la disminución del estado nutricional de los pacientes quemados de ambos sexos durante la hospitalización.

Association of Breastfeeding Duration with Body Composition in Children Aged 3-5 Years / 生物医学与环境科学（英文）

OBJECTIVE@#This study aimed to assess the relationship between the body composition of children aged 3-5 years and breastfeeding status and duration.@*METHODS@#The study was conducted using data from the National Nutrition and Health Systematic Survey for children 0-17 years of age in China (CNHSC), a nationwide cross-sectional study. Breastfeeding information and potential confounders were collected using standardized questionnaires administered through face-to-face interviews. The body composition of preschool children was measured using bioelectrical impedance analysis. A multivariate linear regression model was used to assess the relationship between breastfeeding duration and body composition after adjusting for potential confounders.@*RESULTS@#In total, 2,008 participants were included in the study. Of these, 89.2% were ever breastfed and the median duration of breastfeeding was 12 months (IQR 7-15 months). Among children aged 3 years, the height-for-age Z-score (HAZ) for the ever breastfed group was lower than that for never breastfed group (0.12 vs. 0.42, P = 0.043). In addition, the weight-for-age Z-score (WAZ) of the ever breastfed group was lower than that of the never breastfed group (0.31 vs. 0.65, P = 0.026), and the WAZ was lower in children aged 4 years who breastfed between 12 and 23 months than in those who never breastfed. Compared to the formula-fed children, the fat-free mass of breastfed infants was higher for children aged 3 years (12.84 kg vs. 12.52 kg, P = 0.015) and lower for those aged 4 years (14.31 kg vs. 14.64 kg, P = 0.048), but no difference was detected for children aged 5 years (16.40 kg vs. 16.42 kg, P = 0.910) after adjusting for potential confounders. No significant difference was detected in the weight-for-height Z-score (WHZ), body mass index (BMI)-for-age Z-score (BAZ), fat-free mass index, and body fat indicators in the ever breastfed and never breastfed groups and among various breastfeeding duration groups for children aged 3-5 years.@*CONCLUSION@#No obvious associations were detected between breastfeeding duration, BMI, and fat mass indicators. Future prospective studies should explore the relationship between breastfeeding status and fat-free mass.

Research progress on electrical impedance tomography in pulmonary perfusion / 生物医学工程学杂志

Electrical impedance tomography (EIT) is an emerging technology for real-time monitoring based on the impedance differences of different tissues and organs in the human body. It has been initially applied in clinical research as well as disease diagnosis and treatment. Lung perfusion refers to the blood flow perfusion function of lung tissue, and the occurrence and development of many diseases are closely related to lung perfusion. Therefore, real-time monitoring of lung perfusion is particularly important. The application and development of EIT further promote the monitoring of lung perfusion, and related research has made great progress. This article reviews the principles of EIT imaging, lung perfusion imaging methods, and their clinical applications in recent years, with the aim of providing assistance to clinical and scientific researchers.

Design of a dynamic measurement system for Bl factor spatial distribution of resonant blood viscoelastic sensor / 生物医学工程学杂志

Bl factor is a key system parameter of the resonant blood viscoelastic sensor. In this paper, a dynamic measurement system for the spatial distribution of Bl factor based on velocity amplitude and motional impedance was designed. The system extracted the velocity amplitude and motional impedance of the coil under the dynamic condition of driving the sensor to generate simple harmonic oscillations using laser displacement and impedance analysis combined with in-phase/quadrature demodulation algorithm, and controlled the equilibrium position of the coil by adjusting the direct current component of the excitation current to realize the position scanning. In the position interval of [-240, 240] μm, the maximum coefficient of variation of the measurement results was 0.077 3%, and the maximum relative error to the simulation results was 2.937 9%, with a linear fitting correlation coefficient R 2 = 0.996 8. The system can be used to accurately measure the spatial distribution of Bl factor of the resonant blood viscoelastic sensor, which provides a technical support for the verification of the design of the sensor magnetic circuit.

Human muscle fatigue monitoring method and its application for exoskeleton interactive control / 生物医学工程学杂志

Aiming at the human-computer interaction problem during the movement of the rehabilitation exoskeleton robot, this paper proposes an adaptive human-computer interaction control method based on real-time monitoring of human muscle state. Considering the efficiency of patient health monitoring and rehabilitation training, a new fatigue assessment algorithm was proposed. The method fully combined the human neuromuscular model, and used the relationship between the model parameter changes and the muscle state to achieve the classification of muscle fatigue state on the premise of ensuring the accuracy of the fatigue trend. In order to ensure the safety of human-computer interaction, a variable impedance control algorithm with this algorithm as the supervision link was proposed. On the basis of not adding redundant sensors, the evaluation algorithm was used as the perceptual decision-making link of the control system to monitor the muscle state in real time and carry out the robot control of fault-tolerant mechanism decision-making, so as to achieve the purpose of improving wearing comfort and improving the efficiency of rehabilitation training. Experiments show that the proposed human-computer interaction control method is effective and universal, and has broad application prospects.

Association between the serum adiponectin levels and body composition in perimenopausal and postmenopausal women / 解剖学报

Objective To investigate the relationship between serum adiponectin levels and body composition of perimenopausal and postmenopausal women in central and western Gansu province, and explore the influencing factors of adiponectin levels. Methods The body weight, body mass index(BMI), waist-to-hip, fat mass, percentage of body fat, visceral fat mass and muscle mass of 638 women(317 in perimenopausal period and 321 in postmenopausal period) in central and western Gansu were measured by bioelectrical impedance analyzer. Enzyme linked immunosorbent assay (ELISA)was used to measure serum adiponectin levels. Pearson correlation analysis and multiple liner regression were used to investigate the relationship between adiponectin levels and body composition. Results The body muscle mass of women living in central and western Gansu province showed a downward trend after menopause period compared to those who were in perimenopause. The waist circumference, waist-hip ratio, percentage of body fat, visceral fat mass of postmenopauseal women showed an increasing trend compared to perimenopausal. There were no significant differences in BMI, fat mass and serum adiponectin levels. Overall, serum adiponectin levels were positively correlated with body fat percentage and visceral fat mass, and negatively correlated with muscle mass, and the main influencing factors of serum adiponectin levels were visceral fat mass. Conclusion The main influencing factors of serum adiponectin levels in perimenopausal and postmenopausal women living in central and western Gansu province are the visceral fat mass.

Body composition of Miao nationality in Guizhou and Western Hu'nan / 解剖学报

Objective To explore the influence of regional differences on the body composition of the Miao nationality. Methods The bioelectrical impedance method was used to measure 17 body composition indexes of 357 adults of Miao Nationality in Guizhou (162 males and 195 females) and 471 adults of Miao Nationality in Western Hu'nan (210 males and 261 females). The correlation analysis between body composition and age, One-Way ANOVA and principal component analysis were carried out. Results The visceral fat grade and trunk fat percentage of Miao men in Guizhou and Miao in Western Hu'nan were positively correlated with age, and total muscle mass and trunk muscle mass were negatively correlated with age. The visceral fat grade and trunk fat rate of Miao women in the two regions were positively correlated with age, and the presumed bone mass and trunk muscle mass were negatively correlated with age. The index values of weight, muscle mass, estimated bone mass, water content, visceral fat grade, limb and trunk muscle mass in Guizhou Miao and Miao men in Western Hu'nan were all larger than women, and the body fat rate, limb and trunk fat mass were all smaller than women. The body fat percentages, limbs and trunk fat percentages of Guizhou Miao men and women were similar to those of Xiangxi Miao, and the muscle mass, limbs and trunk muscle mass were less than that of Xiangxi Miao. Conclusion There are obvious regional differences in muscle mass between the Miao nationality in Guizhou and the Miao nationality in Western Hu'nan.

Correlation between sarcopenia,sarcopenic obesity and osteoporosis in adults of Han nationality in Liaoning province / 解剖学报

Objective To understand the prevalence of sarcopenia,sarcopenic obesity and osteoporosis, and to analyze the influence of sarcopenia and sarcopenic obesity on osteoporosis. Methods After all the people signed the informed research agreement, the experimental subjects were selected from Han people over 20 years old in Liaoning region, and a total of 1266 cases were included. The distribution of muscle mass, fat mass and bone mineral density in different parts of adults were measured by bioelectrical impedance analyzer (BIA) and bone densitometer, and the correlation between sarcopenia and sarcopenic obesity and osteoporosis in adults was studied. Results With the increase of age, the muscle mass of limbs, trunk, total muscle mass and body weight of the Han adults in Liaoning showed a trend of increasing at first and then decreasing. There was no significant difference in the prevalence of sarcopenia and sarcopenic obesity between men and women, but there was a significant difference in the prevalence of osteoporosis between men and women. The prevalence of all three groups reached the peak in the age group above 60, and the difference was statistically significant.The risk factor for osteoporosis was sarcopenia and sarcopenic obesity. Conclusion Among adults of Han nationality in Liaoning, the prevalence of sarcopenic obesity,sarcopenia and osteoporosis is significantly different in age. Bone condition is affected by fat mass and muscle mass.

Vaginal Electrical Impedance Detects the Fertile Window in Healthy Women: a Pilot Study / La Impedancia Eléctrica Vaginal Detecta la Ventana Fértil en Mujeres Sanas: un Estudio Piloto

ABSTRACT This work analyzes the electrical impedance (EI) measurement of cervical mucus (CM) using a device to determine the fertile window. In this prospective and longitudinal study, fourteen healthy women aged 18 to 44 were enrolled to evaluate three menstrual cycles. EI was measured through a medical device inserted into the vagina for two minutes daily. Patients were monitored by urine luteinizing hormone (LH) strip, blood collection, and vaginal ultrasound to visualize the dominant follicle. Finally, the predictive EI capacity was validated by the receiver operating characteristic (ROC) of anovulatory vs. ovulatory impedances. The peak of LH was 35.7 (±4.5) mUI/ml and the dominant follicle size was 15.45 mm (±0.559). There were statistical differences in EI measurements between the follicular and luteal phases vs. the ovulation phase (p<0.0361 and p<0.0160). After data normalization, an area under the ROC curve (AUC) of 0.713 (P value= 0.0253), a Youden J index of 0.4545Ω, a sensitivity of 63.6%, and a specificity of 81.8% were found. Low EI in the ovulatory period belongs to the LH ovulatory peak and follicular release. EI can be used for ovulation monitoring, birth control, or promoting pregnancy as a safe and innocuous method.

RESUMEN Este trabajo analiza la medición de la impedancia eléctrica (IE) del moco cervical (MC) mediante un dispositivo para determinar la ventana fértil. En este estudio prospectivo y longitudinal, se incluyeron 14 mujeres sanas de 18 a 44 años para evaluar tres ciclos menstruales. La IE se midió a través de un dispositivo médico colocado en la vagina durante dos minutos diarios. Las pacientes fueron monitoreadas con una tira de hormona luteinizante (LH) en orina, recolección de sangre y ultrasonido vaginal para visualizar el folículo dominante. Finalmente, la capacidad predictiva de IE fue validada por la curva ROC (receiver operating characteristic) de impedancias anovulatorias vs. ovulatorias. El pico de LH fue de 35.7(±4.5) mUI/ml; el folículo de tamaño dominante fue de 15.45 mm (±0.559). Se encontraron diferencias estadísticas para la medición de la IE de las fases folicular y lútea versus la fase de ovulación (p<0.0361 y p<0.0160). Después de la normalización de los datos, se encontró un área bajo la curva ROC (AUC) de 0.713 (valor de P = 0.0253), un índice de Youden J de 0.4545 Ω, sensibilidad del 63.6 % y especificidad del 81.8 %. La IE baja en el período ovulatorio que pertenece al pico ovulatorio de LH y liberación folicular. La IE se puede utilizar para el control de la ovulación, el control de la natalidad o la promoción del embarazo como método seguro e inocuo.

Electrical Impedance Tomography to Measure Spirometry Parameters in Chronic Obstructive Pulmonary Disease Patients / Tomografía por Impedancia Eléctrica para Medir Parámetros de Espirometría en Pacientes con Enfermedad Pulmonar Obstructiva Crónica

ABSTRACT Spirometry is a test for the diagnosis of chronic obstructive pulmonary disease. It is a technique that can be intolerant due to the essential use of a mouthpiece and a clamp. This study proposes the use of electrical impedance tomogra phy to measure respiratory parameters. Patients underwent spirometry and three respiratory exercises. The imped ance signals were convolved, and the resultant was analyzed by fast Fourier transform. The frequency spectrum was divided into seven segments (R1 to R7). Each segment was represented in terms of quartiles (Q25%, Q50%, Q75%). Each quartile of each segment was correlated with the spirometric parameters to obtain a fitting equation. FVC was correlated 70% with the 3 quartiles of R7, 3 equations were obtained with a fit of 60%. FEV1 correlated 70% with the Q50% of R7, obtaining an equation with a fit of 40%. FEV1/FVC correlated 69% with Q75% of R2, obtaining an equation with a fit of 60%. Spirometric parameters can be estimated from the implied carrier frequency components of the ventilatory impedance signal.

RESUMEN La espirometría es una prueba para el diagnóstico de enfermedad pulmonar obstructiva crónica. Es una técnica que puede resultar intolerante debido al uso imprescindible de una boquilla y una de pinza. Este estudio propone el uso de la tomografía de impedancia eléctrica para medir los parámetros respiratorios. Los pacientes realizaron una espi rometría y tres ejercicios respiratorios. Las señales de impedancia fueron convolucionadas, y la resultante se analizó mediante una transformada rápida de Fourier. El espectro en frecuencias se dividió en siete segmentos (R1 a R7). Cada segmento se representó en términos de cuartiles (Q25%, Q50%, Q75%). Cada cuartil de cada segmento se co rrelacionó con los parámetros espirométricos para obtener una ecuación de ajuste. La FVC se correlacionó en un 70% con los 3 cuartiles de R7, se obtuvieron 3 ecuaciones con un ajuste del 60%. El FEV1 se correlacionó en un 70% con el Q50% de R7, obteniéndose una ecuación con un ajuste del 40%. El FEV1/FVC se correlacionó en un 69% con el Q75% de R2, obteniéndose una ecuación con un ajuste del 60%. Los parámetros espirométricos pueden ser estimados a partir de los componentes de frecuencia portadora implícitos de la señal de impedancia ventilatoria.