Sample records for abdominal bioelectrical impedance

  1. EFFECTS OF FOOD AND DRINK INGESTION ON BODY COMPOSITION VARIABLES OF ABDOMINAL BIOELECTRICAL IMPEDANCE.

    PubMed

    Fernández Vázquez, Rosalía; Martínez Blanco, Javier; García Vega, María del Mar; Barbancho, Miguel Ángel; Alvero-Cruz, José Ramón

    2015-11-01

    to know the changes in trunk fat and visceral fat level determined by abdominal bioelectrical impedance (BIA) as well as other anthropometric measures related to the central or abdominal fat after the ingestion of a lunch. the experimental study was conducted to assess a longitudinal intervention descriptive study. 21 subjects (10 male and 11 female), volunteers who have access to a medical assessment, with an age of 74 ± 13.43 years. Maximal waist circumference in standing position, waist circumference at navel level in supine position and sagittal abdominal diameter (SAD). In the same position trunk fat and visceral fat level by abdominal bioelectrical impedance analysis with Tanita AB-140 (ViScan) were obtained before and after meal. anthropometric measures as waist circumference in supine position and SAD did not show significant differences (P > 0.05), after food ingestion, except for a significant increase of the maximal waist circumference in standing position (P < 0.05). In addition trunk fat and visceral fat ratio did not change (P > 0.05). The percentage changes of the measures were less than 2% for waist circumference in standing position, waist circumference by Viscan, sagittal abdominal diameter and trunk fat and 5.9% for visceral fat ratio. the effects on trunk fat and visceral fat ratio by abdominal bioelectrical impedance are minimal after the ingestion of a portion of food and drink, although it is always recommended to do it in fasting conditions. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  2. [Abdomen specific bioelectrical impedance analysis (BIA) methods for evaluation of abdominal fat distribution].

    PubMed

    Ida, Midori; Hirata, Masakazu; Hosoda, Kiminori; Nakao, Kazuwa

    2013-02-01

    Two novel bioelectrical impedance analysis (BIA) methods have been developed recently for evaluation of intra-abdominal fat accumulation. Both methods use electrodes that are placed on abdominal wall and allow evaluation of intra-abdominal fat area (IAFA) easily without radiation exposure. Of these, "abdominal BIA" method measures impedance distribution along abdominal anterior-posterior axis, and IAFA by BIA method(BIA-IAFA) is calculated from waist circumference and the voltage occurring at the flank. Dual BIA method measures impedance of trunk and body surface at the abdominal level and calculates BIA-IAFA from transverse and antero-posterior diameters of the abdomen and the impedance of trunk and abdominal surface. BIA-IAFA by these two BIA methods correlated well with IAFA measured by abdominal CT (CT-IAFA) with correlatipn coefficient of 0.88 (n = 91, p < 0.0001) for the former, and 0.861 (n = 469, p < 0.01) for the latter. These new BIA methods are useful for evaluating abdominal adiposity in clinical study and routine clinical practice of metabolic syndrome and obesity.

  3. [ABDOMINAL BIOELECTRICAL IMPEDANCE ANALYSIS AND ANTHROPOMETRY FOR PREDICTING METABOLIC SYNDROME IN MIDDLE AGED MEN].

    PubMed

    Fernández-Vázquez, Rosalía; Millán Romero, Ángel; Barbancho, Miguel Ángel; Alvero-Cruz, José Ramón

    2015-09-01

    central obesity has a higher risk of metabolic syndrome. The present work aimed to study the relationship of trunk fat and the visceral fat index, and other anthropometric indices in relation to the metabolic syndrome in middle aged male Methods: design: transversal descriptive and correlational study. 75 male, volunteers who have access to a medical assessment, with an age range of 21 to 59 years, from different professions. Weight, height, body mass index, waist circumference, gluteal circumference, waist-to-hip ratio, waist-to-height ratio, trunk fat and visceral fat level by bioelectrical abdominal impedance analysis with Tanita AB-140 (ViScan) and biochemical markers: fasting glucose, total cholesterol, and triglycerides. Likewise, the systolic and diastolic blood pressure was measured. there are significant correlations of anthropometric measurements with trunk fat and visceral fat level and the same with biochemical variables. Receptor-operator curves (ROC curve) analysis shows that the cutoff points from which arises the metabolic syndrome are 32.7% of trunk fat and a level of visceral fat of 13 with a high sensitivity and specificity, attaining the same cut-off points for the metabolic syndrome and obesity status. trunk fat and visceral fat levels determined by bioelectrical abdominal impedance analysis, values are variables very sensitive and specific for the detection of metabolic syndrome and obesity, though not over the variables and anthropometric indices. In the condition of the overweight, trunk fat and visceral fat level are more predictive than anthropometric measures. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  4. Increased abdominal fat levels measured by bioelectrical impedance are associated with histological lesions of nonalcoholic steatohepatitis.

    PubMed

    Margariti, Aikaterini; Kontogianni, Meropi D; Tileli, Nafsika; Georgoulis, Michael; Deutsch, Melanie; Zafeiropoulou, Rodessa; Tiniakos, Dina; Manios, Yannis; Pectasides, Dimitrios; Papatheodoridis, George V

    2015-08-01

    Abdominal fat is considered to play an important role in nonalcoholic fatty liver disease (NAFLD), although it is not adequately studied because abdominal fat levels cannot be estimated easily. In this study, associations between abdominal obesity, as assessed by abdominal bioelectrical impedance analysis (BIA), and the characteristics of patients with NAFLD were explored. Seventy-four consecutive NAFLD patients who underwent measurement of abdominal fat levels by BIA were included. Levels of abdominal fat 12.5 or less and more than 12.5 were considered to be average and increased, respectively. The mean±SD BMI was 30±4 kg/m and the mean abdominal fat levels were 16±5, whereas 26% of patients had average abdominal fat levels. Patients with average compared with those with increased abdominal fat levels were more frequently women (50 vs. 12%, P=0.001), had lower BMI (27±3 vs. 31±4 kg/m, P<0.001), lower Homeostasis Model Assessment index (2.6±1.4 vs. 3.9±2.7, P=0.045), and lower median liver stiffness on transient elastography (5.3 vs. 6.8 kPa, P=0.025). In patients with available liver biopsy, steatohepatitis was present more frequently in patients with increased compared with average abdominal fat levels (78 vs. 38%, P=0.030) and in patients with BMI 30 or more compared with less than 30 kg/m (87 vs. 48%, P=0.033), but similar in patients with increased or normal waist circumference (67 vs. 56%, P=0.693). Average levels of abdominal fat, as assessed by abdominal BIA, are mainly present in female patients with NAFLD and are associated with a lower degree of insulin resistance. Increased abdominal fat as assessed by BIA and obesity seem to represent strong risk factors for histological steatohepatitis.

  5. Visceral fat estimation method by bioelectrical impedance analysis and causal analysis

    NASA Astrophysics Data System (ADS)

    Nakajima, Hiroshi; Tasaki, Hiroshi; Tsuchiya, Naoki; Hamaguchi, Takehiro; Shiga, Toshikazu

    2011-06-01

    It has been clarified that abdominal visceral fat accumulation is closely associated to the lifestyle disease and metabolic syndrome. The gold standard in medical fields is visceral fat area measured by an X-ray computer tomography (CT) scan or magnetic resonance imaging. However, their measurements are high invasive and high cost; especially a CT scan causes X-ray exposure. They are the reasons why medical fields need an instrument for viscera fat measurement with low invasive, ease of use, and low cost. The article proposes a simple and practical method of visceral fat estimation by employing bioelectrical impedance analysis and causal analysis. In the method, abdominal shape and dual impedances of abdominal surface and body total are measured to estimate a visceral fat area based on the cause-effect structure. The structure is designed according to the nature of abdominal body composition to be fine-tuned by statistical analysis. The experiments were conducted to investigate the proposed model. 180 subjects were hired to be measured by both a CT scan and the proposed method. The acquired model explained the measurement principle well and the correlation coefficient is 0.88 with the CT scan measurements.

  6. Feasibility of Bioelectrical Impedance Spectroscopy Measurement before and after Thoracentesis

    PubMed Central

    Weyer, Sören; Pauly, Karolin; Napp, Andreas; Dreher, Michael; Leonhardt, Steffen; Marx, Nikolaus; Schauerte, Patrick; Mischke, Karl

    2015-01-01

    Background. Bioelectrical impedance spectroscopy is applied to measure changes in tissue composition. The aim of this study was to evaluate its feasibility in measuring the fluid shift after thoracentesis in patients with pleural effusion. Methods. 45 participants (21 with pleural effusion and 24 healthy subjects) were included. Bioelectrical impedance was analyzed for “Transthoracic,” “Foot to Foot,” “Foot to Hand,” and “Hand to Hand” vectors in low and high frequency domain before and after thoracentesis. Healthy subjects were measured at a single time point. Results. The mean volume of removed pleural effusion was 1169 ± 513 mL. The “Foot to Foot,” “Hand to Hand,” and “Foot to Hand” vector indicated a trend for increased bioelectrical impedance after thoracentesis. Values for the low frequency domain in the “Transthoracic” vector increased significantly (P < 0.001). A moderate correlation was observed between the amount of removed fluid and impedance change in the low frequency domain using the “Foot to Hand” vector (r = −0.7). Conclusion. Bioelectrical impedance changes in correlation with the thoracic fluid level. It was feasible to monitor significant fluid shifts and loss after thoracentesis in the “Transthoracic” vector by means of bioelectrical impedance spectroscopy. The trial is registered with Registration Numbers IRB EK206/11 and NCT01778270. PMID:25861647

  7. Anisotropic bioelectrical impedance determination of subcutaneous fat thickness

    NASA Astrophysics Data System (ADS)

    Hernández-Becerra, P. A. I.; Delgadillo-Holtfort, I.; Balleza-Ordaz, M.; Huerta-Franco, M. R.; Vargas-Luna, M.

    2014-11-01

    Preliminary results have shown that bioelectrical impedance measurements performed on different parts of the human body strongly depend upon the subcutaneous fat of the considered region. In this work, a method for the determination of subcutaneous fat thickness is explored. Within this method the measurement of the bioelectrical impedance response of the fat-muscle system, both along the direction defined by the muscle fibers and along the corresponding perpendicular direction, are performed. Measurements have been carried out on human female and male subjects of ages around 25 years old at the region of the biceps. Correlation has been performed with skinfold caliper measurements.

  8. Bioelectrical Impedance Methods for Noninvasive Health Monitoring: A Review

    PubMed Central

    Bera, Tushar Kanti

    2014-01-01

    Under the alternating electrical excitation, biological tissues produce a complex electrical impedance which depends on tissue composition, structures, health status, and applied signal frequency, and hence the bioelectrical impedance methods can be utilized for noninvasive tissue characterization. As the impedance responses of these tissue parameters vary with frequencies of the applied signal, the impedance analysis conducted over a wide frequency band provides more information about the tissue interiors which help us to better understand the biological tissues anatomy, physiology, and pathology. Over past few decades, a number of impedance based noninvasive tissue characterization techniques such as bioelectrical impedance analysis (BIA), electrical impedance spectroscopy (EIS), electrical impedance plethysmography (IPG), impedance cardiography (ICG), and electrical impedance tomography (EIT) have been proposed and a lot of research works have been conducted on these methods for noninvasive tissue characterization and disease diagnosis. In this paper BIA, EIS, IPG, ICG, and EIT techniques and their applications in different fields have been reviewed and technical perspective of these impedance methods has been presented. The working principles, applications, merits, and demerits of these methods has been discussed in detail along with their other technical issues followed by present status and future trends. PMID:27006932

  9. Bioelectrical Impedance and Body Composition Assessment

    ERIC Educational Resources Information Center

    Martino, Mike

    2006-01-01

    This article discusses field tests that can be used in physical education programs. The most common field tests are anthropometric measurements, which include body mass index (BMI), girth measurements, and skinfold testing. Another field test that is gaining popularity is bioelectrical impedance analysis (BIA). Each method has particular strengths…

  10. Smart Multi-Frequency Bioelectrical Impedance Spectrometer for BIA and BIVA Applications.

    PubMed

    Harder, Rene; Diedrich, Andre; Whitfield, Jonathan S; Buchowski, Macie S; Pietsch, John B; Baudenbacher, Franz J

    2016-08-01

    Bioelectrical impedance analysis (BIA) is a noninvasive and commonly used method for the assessment of body composition including body water. We designed a small, portable and wireless multi-frequency impedance spectrometer based on the 12 bit impedance network analyzer AD5933 and a precision wide-band constant current source for tetrapolar whole body impedance measurements. The impedance spectrometer communicates via Bluetooth with mobile devices (smart phone or tablet computer) that provide user interface for patient management and data visualization. The export of patient measurement results into a clinical research database facilitates the aggregation of bioelectrical impedance analysis and biolectrical impedance vector analysis (BIVA) data across multiple subjects and/or studies. The performance of the spectrometer was evaluated using a passive tissue equivalent circuit model as well as a comparison of body composition changes assessed with bioelectrical impedance and dual-energy X-ray absorptiometry (DXA) in healthy volunteers. Our results show an absolute error of 1% for resistance and 5% for reactance measurements in the frequency range of 3 kHz to 150 kHz. A linear regression of BIA and DXA fat mass estimations showed a strong correlation (r(2)=0.985) between measures with a maximum absolute error of 6.5%. The simplicity of BIA measurements, a cost effective design and the simple visual representation of impedance data enables patients to compare and determine body composition during the time course of a specific treatment plan in a clinical or home environment.

  11. Discrepancies between leg-to-leg bioelectrical Impedance analysis and computerized tomography in abdominal visceral fat measurement.

    PubMed

    Lu, Hsueh-Kuan; Chen, Yu-Yawn; Yeh, Chinagwen; Chuang, Chih-Lin; Chiang, Li-Ming; Lai, Chung-Liang; Casebolt, Kevin M; Huang, Ai-Chun; Lin, Wen-Long; Hsieh, Kuen-Chang

    2017-08-22

    The aim of this study was to evaluate leg-to-leg bioelectrical impedance analysis (LBIA) using a four-contact electrode system for measuring abdominal visceral fat area (VFA). The present study recruited 381 (240 male and 141 female) Chinese participants to compare VFA measurements estimated by a standing LBIA system (VFALBIA) with computerized tomography (CT) scanned at the L4-L5 vertebrae (VFA CT ). The total mean body mass index (BMI) was 24.7 ± 4.2 kg/m 2 . Correlation analysis, regression analysis, Bland-Altman plot, and paired sample t-tests were used to analyze the accuracy of the VFA LBIA . For the total subjects, the regression line was VFA LBIA  = 0.698 VFA CT  + 29.521, (correlation coefficient (r) = 0.789, standard estimate of error (SEE) = 24.470 cm 2 , p < 0.001), Lin's correlation coefficient (CCC) was 0.785; and the limit of agreement (LOA; mean difference ±2 standard deviation) ranged from -43.950 to 67.951 cm 2 , LOA% (given as a percentage of mean value measured by the CT) was 48.2%. VFA LBIA and VFA CT showed significant difference (p < 0.001). Collectively, the current study indicates that LBIA has limited potential to accurately estimate visceral fat in a clinical setting.

  12. Effect of Intravenous Infusion Solutions on Bioelectrical Impedance Spectroscopy.

    PubMed

    Yap, Jason; Rafii, Mahroukh; Azcue, Maria; Pencharz, Paul

    2017-05-01

    Bioelectrical impedance (BIA) is often used to measure body fluid spaces and thereby body composition. However, in acute animal studies, we found that impedance was driven by the saline content of intravenous (IV) fluids and not by the volume. The aim of the study was to investigate the effect of 3 different fluids acutely administered on the change in impedance, specifically resistance (R). Nine healthy adults participated in 3 treatment (0.9% saline, 5% dextrose, and a mixture of 0.3% saline + 3.3% dextrose) experiments on nonconsecutive days. They all received 1 L of one of the treatments intravenously over a 1-hour period. Repeated BIA measurements were performed prior to IV infusion and then every 5 minutes for the 1-hour infusion period, plus 3 more measurements up to 15 minutes after the completion of the infusion. The change in R in the 0.9% saline infusion experiment was significantly lower than that of the glucose and mixture treatment ( P < .001). Bioelectrical impedance spectroscopy and BIA measure salt rather than the volume changes over the infusion period. Hence, in patients receiving IV fluids, BIA of any kind (single frequency or multifrequency) cannot be used to measure body fluid spaces or body composition.

  13. The Influence of Segmental Impedance Analysis in Predicting Validity of Consumer Grade Bioelectrical Impedance Analysis Devices

    NASA Astrophysics Data System (ADS)

    Sharp, Andy; Heath, Jennifer; Peterson, Janet

    2008-05-01

    Consumer grade bioelectric impedance analysis (BIA) instruments measure the body's impedance at 50 kHz, and yield a quick estimate of percent body fat. The frequency dependence of the impedance gives more information about the current pathway and the response of different tissues. This study explores the impedance response of human tissue at a range of frequencies from 0.2 - 102 kHz using a four probe method and probe locations standard for segmental BIA research of the arm. The data at 50 kHz, for a 21 year old healthy Caucasian male (resistance of 180φ±10 and reactance of 33φ±2) is in agreement with previously reported values [1]. The frequency dependence is not consistent with simple circuit models commonly used in evaluating BIA data, and repeatability of measurements is problematic. This research will contribute to a better understanding of the inherent difficulties in estimating body fat using consumer grade BIA devices. [1] Chumlea, William C., Richard N. Baumgartner, and Alex F. Roche. ``Specific resistivity used to estimate fat-free mass from segmental body measures of bioelectrical impedance.'' Am J Clin Nutr 48 (1998): 7-15.

  14. Bioelectrical Impedance and The Frequency Dependent Current Conduction Through Biological Tissues: A Short Review

    NASA Astrophysics Data System (ADS)

    Kanti Bera, Tushar

    2018-03-01

    Biological tissues are developed with biological cells which exhibit complex electrical impedance called electrical bioimpedance. Under an alternating electrical excitation the bioimpedance varies with the tissue anatomy, composition and the signal frequency. The current penetration and conduction paths vary with frequency of the applied signal. Bioimpedance spectroscopy is used to study the frequency response of the electrical impedance of biological materials noninvasively. In bioimpedance spectroscopy, a low amplitude electrical signal is injected to the tissue sample or body parts to characterization the sample in terms of its bioimpedance. The electrical current conduction phenomena, which is highly influenced by the tissue impedance and the signal frequency, is an important phenomena which should be studied to understand the bioimpedance techniques like bioelectrical impedance analysis (BIA), EIS, or else. In this paper the origin of bioelectrical impedance and current conduction phenomena has been reviewed to present a brief summary of bioelectrical impedance and the frequency dependent current conduction through biological tissues. Simulation studies are conducted with alternation current injection through a two dimensional model of biological tissues containing finite number of biological cells suspended in extracellular fluid. The paper demonstrates the simulation of alternating current conduction through biological tissues conducted by COMSOL Multiphysics. Simulation studies also show the frequency response of the tissue impedance for different tissue compositions.

  15. [Sensitivity and specificity of abdominal adiposity with metabolic syndrome in the elderly].

    PubMed

    Alvero-Cruz, José Ramón; Fernández Vázquez, Rosalía; García Vega, María Del Mar; García Lavigne, Juan Antonio; Rodríguez Linares, María Victoria; Martínez Blanco, Javier

    It is recognised that abdominal adiposity is associated with cardiovascular risk factors, such as intolerance to glucose, hypertension and dyslipidaemia. The objective of the present study was to assess the relationship of trunk fat and visceral fat index, obtained by anthropometric and bioelectrical impedance, with metabolic syndrome (SM) in an elderly population. The study included 208 subjects (78 men and 130 women) with a mean age of 82.5 years. Abdominal obesity was assessed by anthropometry and bioelectrical impedance. ROC curves were calculated in order to assess the ability of these variables to diagnose metabolic syndrome. There are differences between men and women in body mass index, waist to height ratio, waist circumference, and bioelectrical impedance measurements as trunk fat and visceral fat (p<.05). Also, found differences in anthropometric indices and variables and abdominal bioelectrical impedance between subjects with and without SM (p<.05) and only exist differences in blood glucose, triglycerides and HDL cholesterol (p<.05). There are significant correlations between anthropometric variables and abdominal bioelectrical impedance (p<.05). Areas under the curve (AUC) of waist to height index, waist circumference, sagittal abdominal diameter, and trunk fat were greater than 0.8 (all p<.01), and in women did not exceed values of 0.65. The cut-off points obtained for BMI were 26.81 and 23.53kg/m 2 , 102 and 91cm for waist circumference, 22.1 and 20.7cm for sagittal abdominal diameter, 34% and 43.7% for trunk fat, and 17 and 11.5 for visceral fat ratio in men and women, respectively. There are different levels of predictive ability for metabolic syndrome according to gender. Trunk fat and visceral fat index and anthropometric measures have higher predictive ability for metabolic syndrome in men than in women. Copyright © 2016 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Bioelectrical impedance analysis to define an excess of body fat: evaluation in patients with psoriasis.

    PubMed

    Galluzzo, M; Talamonti, M; Perino, F; Servoli, S; Giordano, D; Chimenti, S; De Simone, C; Peris, K

    2017-06-01

    There is strong evidence that obesity is closely associated with psoriasis. However, data on body composition are lacking in psoriasis. The purpose of this study were to investigate the body composition in psoriasis patients using bioelectrical impedance analysis and to correlate the bioelectrical impedance data with disease severity and laboratory parameters. Anthropometric measurements and bioelectrical impedance analyses were performed on patients with psoriasis, naïve to any systemic treatment, who attended the outpatient clinics of two University centers. Data of 164 adult patients were analyzed. Compared to men, women had several significantly higher bioelectrical impedance parameters including reactance, fat mass% and adipose tissue%. The values of adipose tissue were positively correlated only with patients age (p = .021) and age at disease onset (p = .0006), but not with disease severity. In addition, we observed that the use of BMI cutoffs allowed to categorize 36.7% of women and 19.2% of men as obese, while fat mass% showed that 53.3% of women and 48.1% of men were obese. In our study, psoriasis is been associated with a high fat mass%. We suggest that screening for body fat distribution in psoriatic patients might be useful to identify early obesity-related disease.

  17. BIOELECTRICAL IMPEDANCE VECTOR ANALYSIS IDENTIFIES SARCOPENIA IN NURSING HOME RESIDENTS

    USDA-ARS?s Scientific Manuscript database

    Loss of muscle mass and water shifts between body compartments are contributing factors to frailty in the elderly. The body composition changes are especially pronounced in institutionalized elderly. We investigated the ability of single-frequency bioelectrical impedance analysis (BIA) to identify b...

  18. Bioelectrical impedance analysis for bovine milk: Preliminary results

    NASA Astrophysics Data System (ADS)

    Bertemes-Filho, P.; Valicheski, R.; Pereira, R. M.; Paterno, A. S.

    2010-04-01

    This work reports the investigation and analysis of bovine milk quality by using biological impedance measurements using electrical impedance spectroscopy (EIS). The samples were distinguished by a first chemical analysis using Fourier transform midinfrared spectroscopy (FTIR) and flow citometry. A set of milk samples (100ml each) obtained from 17 different cows in lactation with and without mastitis were analyzed with the proposed technique using EIS. The samples were adulterated by adding distilled water and hydrogen peroxide in a controlled manner. FTIR spectroscopy and flow cytometry were performed, and impedance measurements were made in a frequency range from 500Hz up to 1MHz with an implemented EIS system. The system's phase shift was compensated by measuring saline solutions. It was possible to show that the results obtained with the Bioelectrical Impedance Analysis (BIA) technique may detect changes in the milk caused by mastitis and the presence of water and hydrogen peroxide in the bovine milk.

  19. Estimating body fat by using bioelectrical-impedance measurements: a preliminary assessment.

    Treesearch

    M.G. Raphael; H.J. Harlow; S.W. Buskirk

    1991-01-01

    We evaluated a technique for measuring body fat content of marten (Martes americana) by using a noninvasive bioelectrical-impedance device with four electrodes to introduce a current into the body. Instantaneous readings of resistance were significantly correlated with fat-free mass (determined from solvent extraction) of carcasses of 17 skinned (r...

  20. Bioelectrical impedance vector distribution in the first year of life.

    PubMed

    Savino, Francesco; Grasso, Giulia; Cresi, Francesco; Oggero, Roberto; Silvestro, Leandra

    2003-06-01

    We assessed the bioelectrical impedance vector distribution in a sample of healthy infants in the first year of life, which is not available in literature. The study was conducted as a cross-sectional study in 153 healthy Caucasian infants (90 male and 63 female) younger than 1 y, born at full term, adequate for gestational age, free from chronic diseases or growth problems, and not feverish. Z scores for weight, length, cranial circumference, and body mass index for the study population were within the range of +/-1.5 standard deviations according to the Euro-Growth Study references. Concurrent anthropometrics (weight, length, and cranial circumference), body mass index, and bioelectrical impedance (resistance and reactance) measurements were made by the same operator. Whole-body (hand to foot) tetrapolar measurements were performed with a single-frequency (50 kHz), phase-sensitive impedance analyzer. The study population was subdivided into three classes of age for statistical analysis: 0 to 3.99 mo, 4 to 7.99 mo, and 8 to 11.99 mo. Using the bivariate normal distribution of resistance and reactance components standardized by the infant's length, the bivariate 95% confidence limits for the mean impedance vector separated by sex and age groups were calculated and plotted. Further, the bivariate 95%, 75%, and 50% tolerance intervals for individual vector measurements in the first year of life were plotted. Resistance and reactance values often fluctuated during the first year of life, particularly as raw measurements (without normalization by subject's length). However, 95% confidence ellipses of mean vectors from the three age groups overlapped each other, as did confidence ellipses by sex for each age class, indicating no significant vector migration during the first year of life. We obtained an estimate of mean impedance vector in a sample of healthy infants in the first year of life and calculated the bivariate values for an individual vector (95%, 75%, and 50

  1. Assessment of lamb carcass composition from live animal measurement of bioelectrical impedance or ultrasonic tissue depths.

    PubMed

    Berg, E P; Neary, M K; Forrest, J C; Thomas, D L; Kauffman, R G

    1996-11-01

    Market weight lambs, average weight 52.5 kg (+/-6.1), were used to evaluate nontraditional live animal measurements as predictors of carcass composition. The sample population (n = 106) represented U.S. market lambs and transcended geographic location, breed, carcass weight, yield grade, and production system. Realtime ultrasonic (RU) measurements and bioelectrical impedance analysis (BIA) were used for development and evaluation of prediction equations for % boneless, closely trimmed primal cuts (BCTPC), weight or % of dissected lean tissue (TDL), and chemically derived weight or % fat-free lean (FFL). Longitudinal ultrasonic images were obtained parallel to the longissimus thoracis et lumborum (LTL), positioning the last costae in the center of the transducer head. Images were saved and fat and LTL depths were derived from printed images of the ultrasonic scans. Bioelectrical impedance analysis was administered via a four-terminal impedance plethysmograph operating at 800 microA at 50 kHz. Impedance measurements of whole-body resistance and reactance were recorded. Prediction equations including common linear measurements of live weight, heart girth, hindsaddle length, and shoulder height were also evaluated. All measurements were taken just before slaughter. Bioelectrical impedance measurements (as compared to RU and linear measurements) provided equations for %BCTPC, TDL, %TDL, FFL and %FFL with the highest R2 and lowest root mean square error. Even though BIA provided the best equations of the three methodologies tested, prediction of proportional yield (%BCTPC, %TDL, and %FFL) was marginal (R2 = .296, .551, and .551, respectively). Equations combining BIA, RU, and linear measurements greatly improved equations for prediction of proportional lean yield.

  2. Total body composition estimated by standing-posture 8-electrode bioelectrical impedance analysis in male wrestlers.

    PubMed

    Cheng, M-F; Chen, Y-Y; Jang, T-R; Lin, W-L; Chen, J; Hsieh, K-C

    2016-12-01

    Standing-posture 8-electrode bioelectrical impedance analysis is a fast and practical method for evaluating body composition in clinical settings, which can be used to estimate percentage body fat (BF%) and skeletal muscle mass in a subject's total body and body segments. In this study, dual-energy X-ray absorptiometry (DXA) was used as a reference method for validating the standing 8-electrode bioelectrical impedance analysis device BC-418 (BIA 8 , Tanita Corp., Tokyo, Japan). Forty-eight Taiwanese male wrestlers aged from 17.9 to 22.3 years volunteered to participate in this study. The lean soft tissue (LST) and BF% in the total body and body segments were measured in each subject by the BIA 8 and DXA. The correlation coefficients between total body, arm, leg segments impedance index (BI, ht 2 /Z) and lean soft tissue mass measured from DXA were r = 0.902, 0.453, 0.885, respectively (p < 0.01). In addition, the total body and segmental LST estimated by the BIA 8 were highly correlated with the DXA data (r = 0.936, 0.466, 0.886, p < 0.01). The estimation of total body and segmental BF% measured by BIA 8 and DXA also showed a significant correlation (r > 0.820, p < 0.01). The estimated LST and BF% from BIA 8 in the total body and body segments were highly correlated with the DXA results, which indicated that the standing-posture 8-electrode bioelectrical impedance analysis may be used to derive reference measures of LST and BF% in Taiwanese male wrestlers.

  3. Total body composition estimated by standing-posture 8-electrode bioelectrical impedance analysis in male wrestlers

    PubMed Central

    Cheng, M-F; Chen, Y-Y; Jang, T-R; Lin, W-L; Chen, J

    2015-01-01

    Standing-posture 8-electrode bioelectrical impedance analysis is a fast and practical method for evaluating body composition in clinical settings, which can be used to estimate percentage body fat (BF%) and skeletal muscle mass in a subject’s total body and body segments. In this study, dual-energy X-ray absorptiometry (DXA) was used as a reference method for validating the standing 8-electrode bioelectrical impedance analysis device BC-418 (BIA8, Tanita Corp., Tokyo, Japan). Forty-eight Taiwanese male wrestlers aged from 17.9 to 22.3 years volunteered to participate in this study. The lean soft tissue (LST) and BF% in the total body and body segments were measured in each subject by the BIA8 and DXA. The correlation coefficients between total body, arm, leg segments impedance index (BI, ht2/Z) and lean soft tissue mass measured from DXA were r = 0.902, 0.453, 0.885, respectively (p < 0.01). In addition, the total body and segmental LST estimated by the BIA8 were highly correlated with the DXA data (r = 0.936, 0.466, 0.886, p < 0.01). The estimation of total body and segmental BF% measured by BIA8 and DXA also showed a significant correlation (r > 0.820, p < 0.01). The estimated LST and BF% from BIA8 in the total body and body segments were highly correlated with the DXA results, which indicated that the standing-posture 8-electrode bioelectrical impedance analysis may be used to derive reference measures of LST and BF% in Taiwanese male wrestlers. PMID:28090145

  4. Qualitative human body composition analysis assessed with bioelectrical impedance.

    PubMed

    Talluri, T

    1998-12-01

    Body composition is generally aiming at quantitative estimates of fat mass, inadequate to assess nutritional states that on the other hand are well defined by the intra/extra cellular masses proportion (ECM/BCM). Direct measures performed with phase sensitive bioelectrical impedance analyzers can be used to define the current distribution in normal and abnormal populations. Phase angle and reactance nomogram is directly reflecting the ECM/BCM pathways proportions and body impedance analysis (BIA) is also validated to estimate the individual content of body cell mass (BCM). A new body cell mass index (BCMI) obtained dividing the weight of BCM in kilograms by the body surface in square meters is confronted to the scatterplot distribution of phase angle and reactance values obtained from controls and patients, and proposed as a qualitative approach to identify abnormal ECM/BCM ratios and nutritional states.

  5. Body fat measurement by bioelectrical impedance and air displacement plethysmography: a cross-validation study to design bioelectrical impedance equations in Mexican adults

    PubMed Central

    Macias, Nayeli; Alemán-Mateo, Heliodoro; Esparza-Romero, Julián; Valencia, Mauro E

    2007-01-01

    Background The study of body composition in specific populations by techniques such as bio-impedance analysis (BIA) requires validation based on standard reference methods. The aim of this study was to develop and cross-validate a predictive equation for bioelectrical impedance using air displacement plethysmography (ADP) as standard method to measure body composition in Mexican adult men and women. Methods This study included 155 male and female subjects from northern Mexico, 20–50 years of age, from low, middle, and upper income levels. Body composition was measured by ADP. Body weight (BW, kg) and height (Ht, cm) were obtained by standard anthropometric techniques. Resistance, R (ohms) and reactance, Xc (ohms) were also measured. A random-split method was used to obtain two samples: one was used to derive the equation by the "all possible regressions" procedure and was cross-validated in the other sample to test predicted versus measured values of fat-free mass (FFM). Results and Discussion The final model was: FFM (kg) = 0.7374 * (Ht2 /R) + 0.1763 * (BW) - 0.1773 * (Age) + 0.1198 * (Xc) - 2.4658. R2 was 0.97; the square root of the mean square error (SRMSE) was 1.99 kg, and the pure error (PE) was 2.96. There was no difference between FFM predicted by the new equation (48.57 ± 10.9 kg) and that measured by ADP (48.43 ± 11.3 kg). The new equation did not differ from the line of identity, had a high R2 and a low SRMSE, and showed no significant bias (0.87 ± 2.84 kg). Conclusion The new bioelectrical impedance equation based on the two-compartment model (2C) was accurate, precise, and free of bias. This equation can be used to assess body composition and nutritional status in populations similar in anthropometric and physical characteristics to this sample. PMID:17697388

  6. Bioelectrical impedance analysis. What does it measure?

    NASA Technical Reports Server (NTRS)

    Schoeller, D. A.

    2000-01-01

    Bioelectrical impedance analysis (BIA) has been proposed for measuring fat-free mass, total body water, percent fat, body cell mass, intracellular water, and extracellular water: a veritable laboratory in a box. Although it is unlikely that BIA is quite this versatile, correlations have been demonstrated between BIA and all of these body compartments. At the same time, it is known that all of the compartments are correlated among themselves. Because of this, it is difficult to determine whether BIA is specific for any or all of these compartments. To investigate this question, we induced acute changes in total body water and its compartments over a 3-h period. Using this approach, we demonstrated that multifrequency BIA, using the Cole-Cole model to calculate the zero frequency and infinite frequency resistance, measures extracellular and intracellular water.

  7. Bioelectrical impedance vector analysis (BIVA) for measuring the hydration status in young elite synchronized swimmers

    PubMed Central

    Carrasco-Marginet, Marta; Castizo-Olier, Jorge; Rodríguez-Zamora, Lara; Iglesias, Xavier; Rodríguez, Ferran A.; Chaverri, Diego; Brotons, Daniel

    2017-01-01

    Purpose The assessment of body hydration is a complex process, and no measurement is valid for all situations. Bioelectrical impedance vector analysis (BIVA) has emerged as a relatively novel technique for assessing hydration status in sports. We applied BIVA a) to determine hydration changes evoked by an intense synchronized swimming (SS) training session; b) to characterize the sample of young elite swimmers in relation with a nonathletic reference population; and c) to generate its 50%, 75% and 95% percentiles of the bioelectrical variables. Methods Forty-nine elite SS female swimmers of two age categories, comen (Co: 13.9 ± 0.9 years, n = 34) and junior (Jr: 16.3 ± 0.6 years, n = 15), performed a long, high intensity training session. Body mass (BM) and bioelectrical variables (R, resistance; Xc, reactance; PA, phase angle; and Z, impedance module) were assessed pre- and post-training. BIVA was used to characterize 1) the distribution pattern of the bioelectrical vector (BIA vector) for both age groups, and 2) pre- to post-training BIA vector migration. Bioelectrical variables were also correlated with BM change values. Results Most swimmers were mostly located outside the 75% and some beyond the 95% percentile of the bioelectrical tolerance ellipses of the general population. The BIA vector showed statistically significant differences in both Co (T2 = 134.7, p = 0.0001) and Jr (T2 = 126.2, p < 0.001). Both groups were also bioelectrically different (T2 = 17.6, p < 0.001). After the training session, a decrease in BM (p = 0.0001) and an increase in BIA variables (p = 0.01) was observed. BIVA also showed a significant pre-post vector migration both in Co (T2 = 82.1; p < 0.001) and Jr (T2 = 41.8; p < 0.001). No correlations were observed between BM changes and bioelectrical variables. Conclusions BIVA showed specific bioelectrical characteristics in young elite SS athletes. Considering the decrease in BM and the migration of the BIA vector, we conclude that the

  8. Longitudinal validity of abdominal adiposity assessment by regional bioelectrical impedance.

    PubMed

    Alvero-Cruz, José Ramón; García-Romero, Jerónimo C; Carrillo de Albornoz-Gil, Margarita; Jiménez, Manuel; Correas-Gomez, Lorena; Peñaloza, Piero; López-Fernández, Iván; Carnero, Elvis A

    2018-03-20

    The main goal of this study was to analyze the longitudinal agreement between changes in trunk and abdominal adiposity variables assessed by DXA and portable bioimpedance device (ViScan). A total of 44 women, enrolled in a 4-month exercise intervention, were included in this analysis. Trunk/abdominal compartments were assessed by ViScan and DXA. Adjusted correlations for age and FM at first assessment (pre) were utilized to perform concurrent validation among methods and completed with an agreement analysis. We observed significant differences between the changes detected by DXA and ViScan for %TFM (difference = -1.41%; p < 0.05), and proportional bias (Kendall's Tau = 0.53; p < 0.0001). Changes in abdominal adiposity were similar (difference = -0.1037 z-score units, p = 0.53), although there was proportional bias (Kendall's Tau = -0.24, p < 0.022). ViScan has a limited capability to evaluated changes in trunk and abdominal adiposity, at least for clinical purposes in adult women.

  9. Ambulatory Monitoring of Congestive Heart Failure by Multiple Bioelectric Impedance Vectors

    PubMed Central

    Khoury, Dirar S.; Naware, Mihir; Siou, Jeff; Blomqvist, Andreas; Mathuria, Nilesh S.; Wang, Jianwen; Shih, Hue-Teh; Nagueh, Sherif F.; Panescu, Dorin

    2009-01-01

    Objectives To investigate properties of multiple bioelectric impedance signals recorded during congestive heart failure (CHF) by utilizing various electrode configurations of an implanted cardiac resynchronization therapy (CRT) system. Background Monitoring of CHF has relied mainly on right-heart sensors. Methods Fifteen normal dogs underwent implantation of CRT systems using standard leads. An additional left atrial (LA) pressure lead-sensor was implanted in 5 dogs. Continuous rapid right ventricular (RV) pacing was applied over several weeks. Left ventricular (LV) catheterization and echocardiography were performed biweekly. Six steady-state impedance signals, utilizing intrathorcaic and intracardiac vectors, were measured via ring (r), coil (c), and device Can electrodes. Results All animals developed CHF after 2–4 weeks of pacing. Impedance diminished gradually during CHF induction, but at varying rates for different vectors. Impedance during CHF decreased significantly in all measured vectors: LVr-Can, −17%; LVr-RVr, −15%; LVr-RAr, −11%; RVr-Can, −12%; RVc-Can, −7%; RAr-Can, −5%. The LVr-Can vector reflected both the fastest and largest change in impedance in comparison to vectors employing only right-heart electrodes, and was highly reflective of changes in LV end-diastolic volume and LA pressure. Conclusions Impedance, acquired via different lead-electrodes, have variable responses to CHF. Impedance vectors employing a LV lead are highly responsive to physiologic changes during CHF. Measuring multiple impedance signals could be useful for optimizing ambulatory monitoring in heart failure patients. PMID:19298923

  10. Body Composition Comparison: Bioelectric Impedance Analysis with Dual-Energy X-Ray Absorptiometry in Adult Athletes

    ERIC Educational Resources Information Center

    Company, Joe; Ball, Stephen

    2010-01-01

    The primary purpose of this study was to investigate the accuracy of the DF50 (ImpediMed Ltd, Eight Mile Plains, Queensland, Australia) bioelectrical impedance analysis device using dual-energy x-ray absorptiometry as the criterion in two groups: endurance athletes and power athletes. The secondary purpose was to develop accurate body fat…

  11. Field comparison of body composition techniques: hydrostatic weighing, skinfold thickness, and bioelectric impedance.

    PubMed

    Kirkendall, D T; Grogan, J W; Bowers, R G

    1991-01-01

    Body composition and appropriate playing weight are frequently requested by coaches. Numerous methods for estimating these figures are available, and each has its own limitation, be it technical or biological. A comparison of three common methods was made-underwater weighting (H2O, the criterion), skinfold thicknesses (SF), and commercial bioelectrical impedance analysis (BIA). Subjects were 29 professional football players measured by each of the three methods after an overnight fast. Data was collected 10 weeks preceding the players' formal training camp. There was no difference for percentage of weight as fat between SF (15.8%) and H2O (14.2%). Bioelectrical impedance analysis significantly (p < .05) overestimated percent fat (19.2%) compared to H20. Error rates when regressing SF on H2O were favorable, whether expressed for the whole sample (3.04%) or by race (1.78% or 3.56% for whites and blacks, respectively). Regression of BIA on H2O showed an elevated, overall error rate (14.12%) and elevated error rates for whites (11.57%) and blacks (13.81%). Of the two estimates of body composition on a racially mixed sample of males, SF provided the best estimate with the least amount of error. J Orthop Sports Phys Ther 1991;13(5):235-239.

  12. Muscle development in healthy children evaluated by bioelectrical impedance analysis.

    PubMed

    Uchiyama, Tomoka; Nakayama, Takahiro; Kuru, Satoshi

    2017-02-01

    This study aimed to use bioelectrical impedance analysis (BIA) to generate a new muscle density index (MDI), the MDI_BIA, to evaluate muscle development, and to demonstrate the changes that occur in the BIA-based muscle cross-sectional area index (MCAI_BIA) that accompany growth. We also sought to determine the traceability of chronological changes in the MDI_BIA and MCAI_BIA. Healthy children (n=112) aged 8.68±3.16years (0.33-14.00years) underwent bioelectrical impedance (BI) measurements of their upper arms, thighs, and lower legs. The MDI_BIA and MCAI_BIA were calculated, and cross-sectional investigations were conducted into the changes in these indices that accompanied growth. Data collected after 1.10±0.08years from 45 participants determined the traceability of the chronological changes in the MDI_BIA and MCAI_BIA. The MDI_BIA and MCAI_BIA were significantly positively correlated with age and height at all locations (P<0.01). The relationships between the locations and the MDI_BIA and MCAI_BIA differed, indicating that these indices evaluated the muscles from different perspectives. Except for the upper arm MDI_BIA, both indices at all locations regardless of age, showed significant chronological increases after an average period of 1.10years. The MDI_BIA and MCAI_BIA were significantly correlated with age and height in healthy children, and they showed significant chronological increases. Hence, these indices could be used to represent muscle development and muscle mass increases. BIA is non-invasive, convenient, and economical and it may be useful in evaluating muscle development and muscle cross-sectional areas in children. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  13. Smartphone-Based Bioelectrical Impedance Analysis Devices for Daily Obesity Management

    PubMed Central

    Choi, Ahyoung; Kim, Justin Younghyun; Jo, Seongwook; Jee, Jae Hwan; Heymsfield, Steven B.; Bhagat, Yusuf A.; Kim, Insoo; Cho, Jaegeol

    2015-01-01

    Current bioelectric impedance analysis (BIA) systems are often large, cumbersome devices which require strict electrode placement on the user, thus inhibiting mobile capabilities. In this work, we developed a handheld BIA device that measures impedance from multiple frequencies (5 kHz~200 kHz) with four contact electrodes and evaluated the BIA device against standard body composition analysis systems: a dual-energy X-ray absorptiometry (DXA) system (GE Lunar Prodigy, GE Healthcare, Buckinghamshire, UK) and a whole-body BIA system (InBody S10, InBody, Co. Ltd, Seoul, Korea). In the study, 568 healthy participants, varying widely in body mass index, age, and gender, were recruited at two research centers: the Samsung Medical Center (SMC) in South Korea and the Pennington Biomedical Research Center (PBRC) in the United States. From the measured impedance data, we analyzed individual body fat and skeletal muscle mass by applying linear regression analysis against target reference data. Results indicated strong correlations of impedance measurements between the prototype pathways and corresponding InBody S10 electrical pathways (R = 0.93, p < 0.0001). Additionally, body fat estimates from DXA did not yield significant differences (p > 0.728 (paired t-test), DXA mean body fat 29.45 ± 10.77 kg, estimated body fat 29.52 ± 12.53 kg). Thus, this portable BIA system shows a promising ability to estimate an individual’s body composition that is comparable to large stationary BIA systems. PMID:26364636

  14. Assessment of adult body composition using bioelectrical impedance: comparison of researcher calculated to machine outputted values

    PubMed Central

    Franco-Villoria, Maria; Wright, Charlotte M; McColl, John H; Sherriff, Andrea; Pearce, Mark S

    2016-01-01

    Objectives To explore the usefulness of Bioelectrical Impedance Analysis (BIA) for general use by identifying best-evidenced formulae to calculate lean and fat mass, comparing these to historical gold standard data and comparing these results with machine-generated output. In addition, we explored how to best to adjust lean and fat estimates for height and how these overlapped with body mass index (BMI). Design Cross-sectional observational study within population representative cohort study. Setting Urban community, North East England Participants Sample of 506 mothers of children aged 7–8 years, mean age 36.3 years. Methods Participants were measured at a home visit using a portable height measure and leg-to-leg BIA machine (Tanita TBF-300MA). Measures Height, weight, bioelectrical impedance (BIA). Outcome measures Lean and fat mass calculated using best-evidenced published formulae as well as machine-calculated lean and fat mass data. Results Estimates of lean mass were similar to historical results using gold standard methods. When compared with the machine-generated values, there were wide limits of agreement for fat mass and a large relative bias for lean that varied with size. Lean and fat residuals adjusted for height differed little from indices of lean (or fat)/height2. Of 112 women with BMI >30 kg/m2, 100 (91%) also had high fat, but of the 16 with low BMI (<19 kg/m2) only 5 (31%) also had low fat. Conclusions Lean and fat mass calculated from BIA using published formulae produces plausible values and demonstrate good concordance between high BMI and high fat, but these differ substantially from the machine-generated values. Bioelectrical impedance can supply a robust and useful field measure of body composition, so long as the machine-generated output is not used. PMID:26743700

  15. Tissue electrical properties measured by bioelectrical impedance analysis among healthy and sportsmen population

    NASA Astrophysics Data System (ADS)

    Kapica, Dominik; Warchulińska, Joanna; Jakubiak, Monika; Teter, Mariusz; Mlak, Radosław; Hałabiś, Magdalena; Wójcik, Waldemar; Małecka-Massalska, Teresa

    2015-09-01

    Introduction: Bioelectrical impedance analysis (BIA) is a useful tool to asses human body composition and nutrition status; multi-frequency BIA has a higher accuracy than single-frequency BIA. In our study a difference of impedance values (Z) at 5, 100 and 200 kHz and Z200/Z5 index between professional athletes and control group were determined. Methods: In this research 105 people were tested, divided into control group (72 people: 35 males and 37 females) and professional athletes (33 people: 16 males and 17 females). Impedance was measured at three frequency values - 5, 100 and 200 kHz; with received values the Z200/Z5 index was calculated. Results: In most compared subgroups impedance values showed significantly lower values in athletes than in control group (5 kHz - males: p=0.136, females: p=0.001, 100 kHz - males: p=0.039, females: p<0.0001, 200 kHz - males: p=0.047, females: p<0.0001) Z200/Z5 index also showed lower value in athletes than in control group (p=0.016 for males, p<0.0001 for females). Conclusion: Lower values of impedance and Z200/Z5 index indicates a better nutrition status and general health condition of athletes than in control group.

  16. Hydration in advanced cancer: can bioelectrical impedance analysis improve the evidence base? A systematic review of the literature.

    PubMed

    Nwosu, Amara Callistus; Mayland, Catriona R; Mason, Stephen R; Khodabukus, Andrew F; Varro, Andrea; Ellershaw, John E

    2013-09-01

    Decisions surrounding the administration of clinically assisted hydration to patients dying of cancer can be challenging because of the limited understanding of hydration in advanced cancer and a lack of evidence to guide health care professionals. Bioelectrical impedance analysis (BIA) has been used to assess hydration in various patient groupings, but evidence for its use in advanced cancer is limited. To critically appraise existing methods of hydration status assessment in advanced cancer and review the potential for BIA to assess hydration in advanced cancer. Searches were carried out in four electronic databases. A hand search of selected peer-reviewed journals and conference abstracts also was conducted. Studies reporting (de)hydration assessment (physical examination, biochemical measures, symptom assessment, and BIA) in patients with advanced cancer were included. The results highlight how clinical examination and biochemical tests are standard methods of assessing hydration, but limitations exist with these methods in advanced cancer. Furthermore, there is disagreement over the evidence for some commonly associated symptoms with dehydration in cancer. Although there are limitations with using BIA alone to assess hydration in advanced cancer, analysis of BIA raw measurements through the method of bioelectrical impedance vector analysis may have a role in this population. The benefits and burdens of providing clinically assisted hydration to patients dying of cancer are unclear. Bioelectrical impedance vector analysis shows promise as a hydration assessment tool but requires further study in advanced cancer. Innovative methodologies for research are required to add to the evidence base and ultimately improve the care for the dying. Copyright © 2013 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

  17. Assessment of adult body composition using bioelectrical impedance: comparison of researcher calculated to machine outputted values.

    PubMed

    Franco-Villoria, Maria; Wright, Charlotte M; McColl, John H; Sherriff, Andrea; Pearce, Mark S

    2016-01-07

    To explore the usefulness of Bioelectrical Impedance Analysis (BIA) for general use by identifying best-evidenced formulae to calculate lean and fat mass, comparing these to historical gold standard data and comparing these results with machine-generated output. In addition, we explored how to best to adjust lean and fat estimates for height and how these overlapped with body mass index (BMI). Cross-sectional observational study within population representative cohort study. Urban community, North East England Sample of 506 mothers of children aged 7-8 years, mean age 36.3 years. Participants were measured at a home visit using a portable height measure and leg-to-leg BIA machine (Tanita TBF-300MA). Height, weight, bioelectrical impedance (BIA). Lean and fat mass calculated using best-evidenced published formulae as well as machine-calculated lean and fat mass data. Estimates of lean mass were similar to historical results using gold standard methods. When compared with the machine-generated values, there were wide limits of agreement for fat mass and a large relative bias for lean that varied with size. Lean and fat residuals adjusted for height differed little from indices of lean (or fat)/height(2). Of 112 women with BMI >30 kg/m(2), 100 (91%) also had high fat, but of the 16 with low BMI (<19 kg/m(2)) only 5 (31%) also had low fat. Lean and fat mass calculated from BIA using published formulae produces plausible values and demonstrate good concordance between high BMI and high fat, but these differ substantially from the machine-generated values. Bioelectrical impedance can supply a robust and useful field measure of body composition, so long as the machine-generated output is not used. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  18. Evaluation of Bioelectrical Impedance Analysis in Critically Ill Patients: Results of a Multicenter Prospective Study.

    PubMed

    Kuchnia, Adam; Earthman, Carrie; Teigen, Levi; Cole, Abigail; Mourtzakis, Marina; Paris, Michael; Looijaard, Willem; Weijs, Peter; Oudemans-van Straaten, Heleen; Beilman, Gregory; Day, Andrew; Leung, Roger; Compher, Charlene; Dhaliwal, Rupinder; Peterson, Sarah; Roosevelt, Hannah; Heyland, Daren K

    2017-09-01

    In critically ill patients, muscle loss is associated with adverse outcomes. Raw bioelectrical impedance analysis (BIA) parameters (eg, phase angle [PA] and impedance ratio [IR]) have received attention as potential markers of muscularity, nutrition status, and clinical outcomes. Our objective was to test whether PA and IR could be used to assess low muscularity and predict clinical outcomes. Patients (≥18 years) having an abdominal computed tomography (CT) scan and admitted to intensive care underwent multifrequency BIA within 72 hours of scan. CT scans were landmarked at the third lumbar vertebra and analyzed for skeletal muscle cross-sectional area (CSA). CSA ≤170 cm 2 for males and ≤110 cm 2 for females defined low muscularity. The relationship between PA (and IR) and CT muscle CSA was evaluated using multivariate regression and included adjustments for age, sex, body mass index, Charlson Comorbidity Index, and admission type. PA and IR were also evaluated for predicting discharge status using dual-energy x-ray absorptiometry-derived cut-points for low fat-free mass index. Of 171 potentially eligible patients, 71 had BIA and CT scans within 72 hours. Area under the receiver operating characteristic (c-index) curve to predict CT-defined low muscularity was 0.67 ( P ≤ .05) for both PA and IR. With covariates added to logistic regression models, PA and IR c-indexes were 0.78 and 0.76 ( P < .05), respectively. Low PA and high IR predicted time to live ICU discharge. Our study highlights the potential utility of PA and IR as markers to identify patients with low muscularity who may benefit from early and rigorous intervention.

  19. Multiple frequency bioelectrical impedance analysis: a cross-validation study of the inductor circuit and Cole models.

    PubMed

    Ward, L; Cornish, B H; Paton, N I; Thomas, B J

    1999-11-01

    It has been proposed that multiple frequency bioelectrical impedance models of the human body should include an inductive property for the circulatory system, the inductor circuit model (ICM), and that such a model, when coupled with a new method of data analysis, can improve the predictive power of multiple frequency bioelectrical impedance analysis (MFBIA). This hypothesis was tested using MFBIA measurements and gold standard measures of total body and extracellular water volumes in a cross-validation study in two subject groups (viz. controls and HIV). The MFBIA measurements were analysed using the current, widely accepted Cole model and the alternative ICM model which includes an inductive component. Correlations in the range 0.75 to 0.92 (for TBW) and 0.46 to 0.79 (for ECW) for impedance quotients versus gold standard measures within the subject groups were observed. These decreased, to as low as r = 0.50 for TBW and r = 0.29 for ECW, when the derived algorithms were applied to the alternative subject group. These results suggest that lack of portability of MFBIA algorithms between subject groups is not due to an inadequacy of the analogue circuit model per se but is possibly due more to fundamental flaws in the principles associated with its application. These include assuming a constant proportionality of body segment geometries and tissue fluid resistivities. This study has also demonstrated that this inadequacy cannot be overcome by simply introducing an inductive component into the analogue electrical circuit.

  20. Comparison of Bioelectrical Impedance and Skinfolds with Hydrodensitometry in the Assessment of Body Composition in Healthy Young Adults

    ERIC Educational Resources Information Center

    Rutherford, W. J.; Diemer, Gary A.; Scott, Eric D.

    2011-01-01

    Bioelectrical impedance analysis (BIA) is a widely used method for estimating body composition, yet issues concerning its validity persist in the literature. The purpose of this study was to validate percentage of body fat (BF) values estimated from BIA and skinfold (SF) with those obtained from hydrodensitometry (HD). Percent BF values measured…

  1. Lipid and moisture content modeling of amphidromous Dolly Varden using bioelectrical impedance analysis

    USGS Publications Warehouse

    Stolarski, J.T.; Margraf, F.J.; Carlson, J.G.; Sutton, T.M.

    2014-01-01

    The physiological well-being or condition of fish is most commonly estimated from aspects of individual morphology. However, these metrics may be only weakly correlated with nutritional reserves stored as lipid, the primary form of accumulated energy in fish. We constructed and evaluated bioelectrical impedance analysis (BIA) models as an alternative method of assessing condition in amphidromous Dolly Varden Salvelinus malma collected from nearshore estuarine and lotic habitats of the Alaskan Arctic. Data on electrical resistance and reactance were collected from the lateral and ventral surfaces of 192 fish, and whole-body percent lipid and moisture content were determined using standard laboratory methods. Significant inverse relationships between temperature and resistance and reactance prompted the standardization of these data to a constant temperature using corrective equations developed herein. No significant differences in resistance or reactance were detected among spawning and nonspawning females after accounting for covariates, suggesting that electrical pathways do not intersect the gonads. Best-fit BIA models incorporating electrical variables calculated from the lateral and ventral surfaces produced the strongest associations between observed and model-predicted estimates of proximate content. These models explained between 6% and 20% more of the variability in laboratory-derived estimates of proximate content than models developed from single-surface BIA data and 32% more than models containing only length and weight data. While additional research is required to address the potential effects of methodological variation, bioelectrical impedance analysis shows promise as a way to provide high-quality, minimally invasive estimates of Dolly Varden lipid or moisture content in the field with only small increases in handling time.

  2. Percentiles of body fat measured by bioelectrical impedance in children and adolescents from Bogotá (Colombia): the FUPRECOL study.

    PubMed

    Escobar-Cardozo, Germán D; Correa-Bautista, Jorge E; González-Jiménez, Emilio; Schmidt-RioValle, Jacqueline; Ramírez-Vélez, Robinson

    2016-04-01

    The analysis of body composition is a fundamental part of nutritional status assessment. The objective of this study was to establish body fat percentiles by bioelectrical impedance in children and adolescents from Bogotá (Colombia) who were part of the FUPRECOL study (Asociación de la Fuerza Prensil con Manifestaciones Tempranas de Riesgo Cardiovascular en Niños y Adolescentes Colombianos - Association between prehensile force and early signs of cardiovascular risk in Colombian children and adolescents). This was a cross-sectional study conducted among 5850 students aged 9-17.9 years old from Bogotá (Colombia). Body fat percentage was measured using foot-to-foot bioelectrical impedance (Tanita®, BF-689), by age and gender. Weight, height, waist circumference, and hip circumference were measured, and sexual maturity was self-staged. Percentiles (P3, P10, P25, P50, P75, P90 and P97) and centile curves were estimated using the LMS method (L [BoxCox curve], M [median curve] and S [variation coefficient curve]), by age and gender. Subjects included were 2526 children and 3324 adolescents. Body fat percentages and centile curves by age and gender were established. For most age groups, values resulted higher among girls than boys. Participants with values above P90 were considered to have a high cardiovascular risk due to excess fat (boys > 23.428.3, girls > 31.0-34.1). Body fat percentage percentiles measured using bioelectrical impedance by age and gender are presented here and may be used as reference to assess nutritional status and to predict cardiovascular risk due to excess fat at an early age. Sociedad Argentina de Pediatría.

  3. Validity of segmental bioelectrical impedance analysis for estimating fat-free mass in children including overweight individuals.

    PubMed

    Ohta, Megumi; Midorikawa, Taishi; Hikihara, Yuki; Masuo, Yoshihisa; Sakamoto, Shizuo; Torii, Suguru; Kawakami, Yasuo; Fukunaga, Tetsuo; Kanehisa, Hiroaki

    2017-02-01

    This study examined the validity of segmental bioelectrical impedance (BI) analysis for predicting the fat-free masses (FFMs) of whole-body and body segments in children including overweight individuals. The FFM and impedance (Z) values of arms, trunk, legs, and whole body were determined using a dual-energy X-ray absorptiometry and segmental BI analyses, respectively, in 149 boys and girls aged 6 to 12 years, who were divided into model-development (n = 74), cross-validation (n = 35), and overweight (n = 40) groups. Simple regression analysis was applied to (length) 2 /Z (BI index) for each of the whole-body and 3 segments to develop the prediction equations of the measured FFM of the related body part. In the model-development group, the BI index of each of the 3 segments and whole body was significantly correlated to the measured FFM (R 2 = 0.867-0.932, standard error of estimation = 0.18-1.44 kg (5.9%-8.7%)). There was no significant difference between the measured and predicted FFM values without systematic error. The application of each equation derived in the model-development group to the cross-validation and overweight groups did not produce significant differences between the measured and predicted FFM values and systematic errors, with an exception that the arm FFM in the overweight group was overestimated. Segmental bioelectrical impedance analysis is useful for predicting the FFM of each of whole-body and body segments in children including overweight individuals, although the application for estimating arm FFM in overweight individuals requires a certain modification.

  4. Bioelectrical Impedance Vector Analysis and Muscular Fitness in Healthy Men

    PubMed Central

    Rodríguez-Rodríguez, Fernando; Cristi-Montero, Carlos; González-Ruíz, Katherine; Correa-Bautista, Jorge Enrique; Ramírez-Vélez, Robinson

    2016-01-01

    Muscle strength can define the general muscular fitness (MF) measurable through hand-grip strength (HG), which is a factor that relates to the health of people of different ages. In this study we evaluated the muscle strength together with a bioimpedance electric analysis in 223 healthy Colombian adult subjects. The bioelectrical impedance vector analysis (BIVA) was conducted to determine the resistance (R), reactance (Xc) and phase angle (PhA). We classified the subjects into three groups (for tertiles), obtaining lower values of R and Xc in subjects with lower HG, plus a high correlation between PhA and HG. An increase in the level of PhA is associated with a high level of MF in a sample of healthy Latin American adult men. The BIVA’s parameters and PhA are a potentially effective preventive measure to be integrated into routine screening in the clinical setting. PMID:27384579

  5. Prediction of beef carcass salable yield and trimmable fat using bioelectrical impedance analysis.

    PubMed

    Zollinger, B L; Farrow, R L; Lawrence, T E; Latman, N S

    2010-03-01

    Bioelectrical impedance technology (BIA) is capable of providing an objective method of beef carcass yield estimation with the rapidity of yield grading. Electrical resistance (Rs), reactance (Xc), impedance (I), hot carcass weight (HCW), fat thickness between the 12th and 13th ribs (FT), estimated percentage kidney, pelvic, and heart fat (KPH%), longissimus muscle area (LMA), length between electrodes (LGE) as well as three derived carcass values that included electrical volume (EVOL), reactive density (XcD), and resistive density (RsD) were determined for the carcasses of 41 commercially fed cattle. Carcasses were subsequently fabricated into salable beef products reflective of industry standards. Equations were developed to predict percentage salable carcass yield (SY%) and percentage trimmable fat (FT%). Resulting equations accounted for 81% and 84% of variation in SY% and FT%, respectively. These results indicate that BIA technology is an accurate predictor of beef carcass composition. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. Assessment of the Body Composition and the Loss of Fat-Free Mass through Bioelectric Impedance Analysis in Patients Who Underwent Open Gastric Bypass

    PubMed Central

    de Freitas Junior, Wilson Rodrigues; Ilias, Elias Jirjoss; Kassab, Paulo; Cordts, Roberto; Porto, Paulo Gustavo; Martins Rodrigues, Francisco Cesar; Ali Taha, Mohamed Ibrahim; Carrara, Paulo; de Carvalho Aguiar, Isabella; de Oliveira, Luis Vicente Franco; Malheiros, Carlos Alberto

    2014-01-01

    Background. Bariatric surgery is considered an effective option for the management of morbid obesity. The incidence of obesity has been gradually increasing all over the world reaching epidemic proportions in some regions of the world. Obesity can cause a reduction of up to 22% in the life expectancy of morbidly obese patients. Objective. The objective of this paper is to assess the weight loss associated with the first 6 months after bariatric surgery using bioelectric impedance analysis (BIA) for the evaluation of fat mass and fat-free mass. Method. A total of 36 morbidly obese patients were subjected to open gastric bypass surgery. The patients weight was monitored before and after the procedure using the bioelectric impedance analysis. Results. Bariatric surgery resulted in an average percentage of weight loss of 28.6% (40 kg) as determined 6 months after the procedure was performed. Analysis of the different components of body weight indicated an undesirable loss of fat-free mass along with the reduction of total body weight. Conclusion. Open gastric bypass induced a significant loss of total weight and loss of fat-free mass in patients six months after the surgery. The use of bioelectric impedance analysis resulted in an appropriate estimation of the total weight components in individuals subjected to bariatric surgery allowing a more real analysis of the variation of weight after the surgery. PMID:24523649

  7. Uterine Junctional Zone Thickness, Cervical Length and Bioelectrical Impedance Analysis of Body Composition in Women with Endometriosis

    PubMed Central

    Ayas, Selçuk; Bayraktar, Mesut; Gürbüz, Ayşe; Alkan, Akif; Eren, Sadiye

    2012-01-01

    Objective: We aimed to evaluate uterine junctional zone thickness, cervical length and bioelectrical impedance analysis of body composition in women with endometriosis. Material and Methods: This is a prospective study conducted in a tertiary teaching hospital. A total of 73 patients were included in the study. Endometriosis was surgically diagnosed in 36 patients (study group). The control group included 37 patients. Main outcome measure(s): Bioelectrical impedance analysis was used to measure body composition. Uterine junctional zone thickness and cervical length were measured by transvaginal ultrasonography. Results: Patients’ characteristics (age, gravida, parity, live baby, age of menarche, lengths of menstrual cycle, percentage of patients with dysmenorrhea, positive family history), body mass index (BMI) (kg/m2), amount of body fat (kg), percentage of body fat were not statistically different between the two groups (p>0.05). The length of menstruation and cervical length were longer in women with endometriosis. Similarly, the inner myometrium was thicker in women with endometriosis than the control group. Conclusion: The relation between endometriosis and demographic features such as age, gravida, parity, gravida, BMI, lengths of the menstrual cycle, age of menarche are controversial. Longer cervical length and thicker inner myometrial layer may be important in the etiopathogenesis of endometriosis. PMID:25207044

  8. Bioelectrical impedance analysis: A new tool for assessing fish condition

    USGS Publications Warehouse

    Hartman, Kyle J.; Margraf, F. Joseph; Hafs, Andrew W.; Cox, M. Keith

    2015-01-01

    Bioelectrical impedance analysis (BIA) is commonly used in human health and nutrition fields but has only recently been considered as a potential tool for assessing fish condition. Once BIA is calibrated, it estimates fat/moisture levels and energy content without the need to kill fish. Despite the promise held by BIA, published studies have been divided on whether BIA can provide accurate estimates of body composition in fish. In cases where BIA was not successful, the models lacked the range of fat levels or sample sizes we determined were needed for model success (range of dry fat levels of 29%, n = 60, yielding an R2 of 0.8). Reduced range of fat levels requires an increased sample size to achieve that benchmark; therefore, standardization of methods is needed. Here we discuss standardized methods based on a decade of research, identify sources of error, discuss where BIA is headed, and suggest areas for future research.

  9. Effect of Exercise Intensity on Percent Body Fat Determined by Leg-to-Leg and Segmental Bioelectrical Impedance Analyses in Adults

    ERIC Educational Resources Information Center

    Andreacci, Joseph L.; Nagle, Trisha; Fitzgerald, Elise; Rawson, Eric S.; Dixon, Curt B.

    2013-01-01

    Purpose: We examined the impact that cycle ergometry exercise had on percent body fat (%BF) estimates when assessed using either leg-to-leg or segmental bioelectrical impedance analysis (LBIA; SBIA) and whether the intensity of the exercise bout impacts the %BF magnitude of change. Method: Seventy-four college-aged adults participated in this…

  10. Gender differences and age-related changes in body fat mass in Tibetan children and teenagers: an analysis by the bioelectrical impedance method.

    PubMed

    Zhang, Hai-Long; Fu, Qiang; Li, Wen-Hui; Liu, Su-Wei; Zhong, Hua; Duoji, Bai-Ma; Zhang, Mei-Zhi; Lv, Po; Xi, Huan-Jiu

    2015-01-01

    We aimed to obtain the fat base value and the fat distribution characteristics of Tibetan children and teenagers by estimating their body fat content with the bioelectrical impedance method. We recruited 1427 healthy children and teenagers by a stratified cluster sampling method. By using bioelectrical impedance analysis, we obtained various values relevant to fat. We found that total body fat mass and the fat mass of various body parts increased with age in boys and girls. Yet there were no differences between age groups until 11 years. However, fat mass increased quickly between 11 and 18 years, and significant differences were seen between adolescent boys and girls; all fat indices were higher in girls than in boys (p<0.05). The characteristics of fat in Tibetan children and teenagers in Tibet is related to age and gender related hormone secretion, which reflects the physiological characteristics in different developmental stages.

  11. Bioelectrical impedance analysis and anthropometry in Ecuadorian children of African ancestry.

    PubMed

    Vienna, A; Capucci, E; De Stefano, G F; Hauser, G

    1998-12-01

    In the city of Esmeraldas, north-western coast of Ecuador, height, weight, and body composition of 600 male and female schoolchildren of African ancestry in the age groups four, five and six years were investigated. All the children were apparently healthy without any obvious or reported pathologies and in accordance with data from personal information were assigned to one of two socio-economic classes. The greater values for weight and height shown by children in the higher socio-economic group than in the less well off are compatible with those for more fat and water as obtained by the BIA investigation. Additional information on nutritional, muscular and general health status was obtained from positioning and degree of dispersion of the 'Biagram' ellipses. It seems that both the anthropometric and the bioelectrical impedance methods provide useful information on the differences due to belonging to one or other of the socio-economic groups.

  12. Can Total Body Resistance Measured Using Bioelectrical Impedance Analysis Be the Index of Dehydration in Older Japanese Patients?

    PubMed

    Shimizu, Miyuki; Kinoshita, Kensuke; Maeno, Takami; Kobayashi, Hiroyuki; Maeno, Tetsuhiro

    2017-11-01

    Dehydration in older patients has long been considered a significant health problem because it implies increased morbidity and mortality. However, dehydration is detected by a combination of physical signs and blood tests. For older people dwelling at home and in nursing homes, a simple and non-invasive method for detecting dehydration by caregivers is needed. The total body resistance is measured using bioelectrical impedance analysis and is known as an indicator of dehydration. There are no data from older Japanese patients on this issue. We performed this study to examine the relationship between dehydration and total body resistance in Japan. We performed blood tests and measured bioelectrical impedance in older outpatients aged ≥ 65 years from the Internal Medicine Department at Mito Kyodo General Hospital. Patients were classified as dehydrated and non-dehydrated using the dehydration index with a blood urea nitrogen/creatinine ratio > 20, and the mean total body resistance was compared between the two groups. Eighty-one patients were recruited in the study. In the dehydrated group, the mean total body resistance was 439 Ω at 50 kHz, which was significantly higher than that in the non-dehydrated group (408 Ω, P = 0.038). The total body resistance measurements can be used for simple assessment of dehydration among older Japanese patients.

  13. Validity and reliability of bioelectrical impedance analysis and skinfold thickness in predicting body fat in military personnel.

    PubMed

    Aandstad, Anders; Holtberget, Kristian; Hageberg, Rune; Holme, Ingar; Anderssen, Sigmund A

    2014-02-01

    Previous studies show that body composition is related to injury risk and physical performance in soldiers. Thus, valid methods for measuring body composition in military personnel are needed. The frequently used body mass index method is not a valid measure of body composition in soldiers, but reliability and validity of alternative field methods are less investigated in military personnel. Thus, we carried out test and retest of skinfold (SKF), single frequency bioelectrical impedance analysis (SF-BIA), and multifrequency bioelectrical impedance analysis measurements in 65 male and female soldiers. Several validated equations were used to predict percent body fat from these methods. Dual-energy X-ray absorptiometry was also measured, and acted as the criterion method. Results showed that SF-BIA was the most reliable method in both genders. In women, SF-BIA was also the most valid method, whereas SKF or a combination of SKF and SF-BIA produced the highest validity in men. Reliability and validity varied substantially among the equations examined. The best methods and equations produced test-retest 95% limits of agreement below ±1% points, whereas the corresponding validity figures were ±3.5% points. Each investigator and practitioner must consider whether such measurement errors are acceptable for its specific use. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

  14. Predictive validity of four bioelectrical impedance equations in determining percent fat mass in overweight and obese children.

    PubMed

    Cleary, Jane; Daniells, Suzie; Okely, Anthony D; Batterham, Marijka; Nicholls, Jessie

    2008-01-01

    Bioelectrical impedance equations are frequently used by food and nutrition professionals to estimate percent fat mass in overweight and obese children. However, it is not known whether they are accurate for such children, as they have been primarily developed for children of varying body weights. The aim of this cross-sectional study was to evaluate the predictive validity of four previously published prediction equations developed for the pediatric population, among a sample of overweight and obese children. Thirty overweight or obese children (mean age=7.57+/-1.28 years) underwent measurement of fat mass, percent fat mass, and fat-free mass using dual-energy x-ray absorptiometry (DEXA) and bioelectrical impedance analysis (BIA). Impedance values from the BIA were entered into the four prediction equations and Pearson correlations used to determine the significance of associations between each of the BIA prediction equations and DEXA for percent fat mass, fat mass, and fat-free mass. For percent fat mass, paired t tests were used to assess differences between the methods and the technique of Bland and Altman was used to determine bias and error. Results showed that the mean percent fat mass as determined by DEXA for this age group was 40.79%. In comparison with other BIA prediction equations, the Schaefer equation had the closest mean value of 41.98%, and was the only equation not to significantly differ from the DEXA (P=0.121). This study suggests that the Schaefer equation is the only accurate BIA prediction equation for assessing percent fat mass in this sample of overweight and obese children from primarily white backgrounds.

  15. Foot-to-foot bioelectrical impedance accurately tracks direction of adiposity change in overweight and obese 7- to 13-year-old children.

    PubMed

    Kasvis, Popi; Cohen, Tamara R; Loiselle, Sarah-Ève; Kim, Nicolas; Hazell, Tom J; Vanstone, Catherine A; Rodd, Celia; Plourde, Hugues; Weiler, Hope A

    2015-03-01

    Body composition measurements are valuable when evaluating pediatric obesity interventions. We hypothesized that foot-to-foot bioelectrical impedance analysis (BIA) will accurately track the direction of adiposity change, but not magnitude, in part due to differences in fat patterning. The purposes of this study were to examine the accuracy of body composition measurements of overweight and obese children over time using dual-energy x-ray absorptiometry (DXA) and BIA and to determine if BIA accuracy was affected by fat patterning. Eighty-nine overweight or obese children (48 girls, 41 boys, age 7-13 years) participating in a randomized controlled trial providing a family-centered, lifestyle intervention, underwent DXA and BIA measurements every 3 months. Bland-Altman plots showed a poor level of agreement between devices for baseline percent body fat (%BF; mean, 0.398%; +2SD, 8.685%; -2SD, -7.889%). There was overall agreement between DXA and BIA in the direction of change over time for %BF (difference between visits 3 and 1: DXA -0.8 ± 0.5%, BIA -0.7 ± 0.5%; P = 1.000) and fat mass (FM; difference between visits 3 and 1: DXA 0.7 ± 0.5 kg, BIA 0.6 ± 0.5 kg; P = 1.000). Bioelectrical impedance analysis measurements of %BF and FM at baseline were significantly different in those with android and gynoid fat (%BF: 35.9% ± 1.4%, 32.2% ± 1.4%, P < .003; FM: 20.1 ± 0.8 kg, 18.4 ± 0.8, P < .013). Bioelectrical impedance analysis accurately reports the direction of change in FM and FFM in overweight and obese children; inaccuracy in the magnitude of BIA measurements may be a result of fat patterning differences. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Determination of saleable product in finished cattle and beef carcasses utilizing bioelectrical impedance technology.

    PubMed

    Marchello, M J; McLennan, J E; Dhuyvetter, D V; Slanger, W D

    1999-11-01

    Two experiments were performed to develop prediction equations of saleable beef and to validate the prediction equations. In Exp. 1, 50 beef cattle were finished to typical slaughter weights, and multiple linear regression equations were developed to predict kilograms of trimmed boneless, retail product of live cattle, and hot and cold carcasses. A four-terminal bioelectrical impedance analyzer (BIA) was used to measure resistance (Rs) and reactance (Xc) on each animal and processed carcass. The IMPS cuts plus trim were weighed and recorded. Distance between detector terminals (Lg) and carcass temperature (Tp) at time of BIA readings were recorded. Other variables included live weight (BW), hot carcass weight (HCW), cold carcass weight (CCW), and volume (Lg2/Rs). Regression equations for predicting kilograms of saleable product were [11.87 + (.409 x BW) - (.335 x Lg) + (.0518 x volume)] for live (R2 = .80); [-58.83 + (.589 x HCW) - (.846 x Rs) + (1.152 x Xc) + (.142 x Lg) + (2.608 x Tp)] for hot carcass (R2 = .95); and [32.15 + (.633 x CCW) + (.33 x Xc) - (.83 x Lg) + (.677 x volume)] for cold carcass (R2 = .93). In Exp. 2, 27 beef cattle were finished in a manner similar to Exp. 1, and the prediction equations from Exp. 1 were used to predict the saleable product of these animals. The Pearson correlations between actual saleable product and the predictions based on live and cold carcass data were .91 and .95, respectively. The Spearman and Kendall rank correlations were .95 and .83, respectively, for the cold carcass data. These results provide a practical application of bioelectrical impedance for market-based pricing. They complement previous studies that assessed fat-free mass.

  17. Measuring body composition in dogs using multifrequency bioelectrical impedance analysis and dual energy X-ray absorptiometry.

    PubMed

    Rae, L S; Vankan, D M; Rand, J S; Flickinger, E A; Ward, L C

    2016-06-01

    Thirty-five healthy, neutered, mixed breed dogs were used to determine the ability of multifrequency bioelectrical impedance analysis (MFBIA) to predict accurately fat-free mass (FFM) in dogs using dual energy X-ray absorptiometry (DXA)-measured FFM as reference. A second aim was to compare MFBIA predictions with morphometric predictions. MFBIA-based predictors provided an accurate measure of FFM, within 1.5% when compared to DXA-derived FFM, in normal weight dogs. FFM estimates were most highly correlated with DXA-measured FFM when the prediction equation included resistance quotient, bodyweight, and body condition score. At the population level, the inclusion of impedance as a predictor variable did not add substantially to the predictive power achieved with morphometric variables alone; in individual dogs, impedance predictors were more valuable than morphometric predictors. These results indicate that, following further validation, MFBIA could provide a useful tool in clinical practice to objectively measure FFM in canine patients and help improve compliance with prevention and treatment programs for obesity in dogs. Copyright © 2016. Published by Elsevier Ltd.

  18. Bioelectrical impedance vector analysis detects low body cell mass and dehydration in patients with Alzheimer's disease.

    PubMed

    Buffa, R; Mereu, R M; Putzu, P F; Floris, G; Marini, E

    2010-12-01

    This paper evaluates the nutritional status in patients with mild-moderate and severe Alzheimer's disease (AD) by bioelectrical impedance vector analysis (BIVA). Cross-sectional study. Alzheimer Center, SS. Trinita Hospital, Cagliari, and "Monsignor Angioni" Nursing Home, Quartu Sant'Elena (Cagliari, Italy). 83 free-living patients with mild-moderate Alzheimer's disease (29 men, 54 women), 9 institutionalized women in the severe stage; 468 age-matched controls (202 men, 266 women). Mini Nutritional Assessment (MNA), anthropometric (height, weight, BMI), bioelectrical (R, Xc) and biochemical variables (serum albumin) were assessed. Bioelectrical characteristics were significantly different in the patients with mild-moderate AD with respect to controls, indicating low body cell mass (men, T2= 12.8; women, T2=34.9; p < 0.01). Women with severe AD showed low body cell mass and dehydration with respect to patients with mild-moderate AD (T2=17.1; p < 0.01). The phase angle, R/H and Z/H were significantly correlated (p < 0.05) with MNA (phase: r = 0.31; R/H: r =-0.37; Z/H: r =-0.37) and albumin (phase: r=0.47; R/H: r=-0.36; Z/H: r=-0.36). Alzheimer's disease is characterized by a tendency to malnutrition, present even in the mild-moderate stages, and a tendency to dehydration that appears in the severe stage. The BIVA technique is a promising tool for the screening and monitoring of nutrition and hydration status in Alzheimer's disease.

  19. Prediction of maximal oxygen uptake by bioelectrical impedance analysis in overweight adolescents.

    PubMed

    Roberts, M D; Drinkard, B; Ranzenhofer, L M; Salaita, C G; Sebring, N G; Brady, S M; Pinchbeck, C; Hoehl, J; Yanoff, L B; Savastano, D M; Han, J C; Yanovski, J A

    2009-09-01

    Maximal oxygen uptake (VO(2max)), the gold standard for measurement of cardiorespiratory fitness, is frequently difficult to assess in overweight individuals due to physical limitations. Reactance and resistance measures obtained from bioelectrical impedance analysis (BIA) have been suggested as easily obtainable predictors of cardiorespiratory fitness, but the accuracy with which ht(2)/Z can predict VO(2max) has not previously been examined in overweight adolescents. The impedance index was used as a predictor of VO(2max) in 87 overweight girls and 47 overweight boys ages 12 to 17 with mean BMI of 38.6 + or - 7.3 and 42.5 + or - 8.2 in girls and boys respectively. The Bland Altman procedure assessed agreement between predicted and actual VO(2max). Predicted VO(2max) was significantly correlated with measured VO(2max) (r(2)=0.48, P<0.0001). Using the Bland Altman procedure, there was significant magnitude bias (r(2)=0.10; P<0.002). The limits of agreement for predicted relative to actual VO(2max) were -589 to 574 mL O(2)/min. The impedance index was highly correlated with VO(2max) in overweight adolescents. However, using BIA data to predict maximal oxygen uptake over-predicted VO(2max) at low levels of oxygen consumption and under-predicted VO(2max) at high levels of oxygen consumption. This magnitude bias, along with the large limits of agreement of BIA-derived predicted VO(2max), limit its usefulness in the clinical setting for overweight adolescents.

  20. Assessing Body Fat Changes during Moderate Weight Loss with Anthropometry and Bioelectrical Impedance

    PubMed Central

    Aslam, Muhammad; Eckhauser, Aaron W.; Dorminy, Cindy A.; Dossett, Cynthia M.; Choi, Leena; Buchowski, Maciej S.

    2009-01-01

    Background/Objectives Monitoring changes in total fat mass and abdominal adiposity are important in understanding the impact of different types of weight loss interventions on health risks. Our objective was to assess the usefulness of anthropometry and bioelectrical impedance analysis (BIA) in predicting fat mass changes during moderate weight loss. Subjects/Methods Fat mass changes were assessed in 34 overweight adults (24 females, 10 males) after a 12-week supervised weight loss induced by caloric restriction (−30% of requirement) using BIA and DXA. Agreement between BIA and DXA measurements were assessed by Bland-Altman plots. Linear regression modeling was used to predict body and truncal fat mass from anthropometric measures. Results Diet intervention resulted in a significant decrease in body weight (− 7.86 ± 2.87 kg), body mass index (BMI − 2.69 ± 0.98 kg/m2), total body fat (− 5.22 ± 2.32 kg), truncal fat (− 2.80 ± 1.94 kg) and waist circumference (− 5.52 ± 3.57 cm). BMI and body weight were highly correlated with body fat (0.83 and 0.92 in females and 0.94 and 0.92 in males respectively) and truncal fat (0.75 and 0.87 in females; 0.90 and 0.84 in males respectively) during weight loss. Waist circumference was more correlated with truncal fat in males than females (0.94 vs. 0.85 in females). Compared to DXA, BIA underestimated total body fat changes in males (− 8.8 kg, p<0.001) and overestimated total body fat changes in females (+ 2.1 kg, p< 0.001). Conclusions Body mass index, body weight, and waist circumference provide simple and more accurate than BIA estimates of relative changes in total and truncal fat during moderate weight loss in adults. PMID:20161645

  1. The use of bioelectrical impedance analysis to estimate total body water in young children with cerebral palsy.

    PubMed

    Bell, Kristie L; Boyd, Roslyn N; Walker, Jacqueline L; Stevenson, Richard D; Davies, Peter S W

    2013-08-01

    Body composition assessment is an essential component of nutritional evaluation in children with cerebral palsy. This study aimed to validate bioelectrical impedance to estimate total body water in young children with cerebral palsy and determine best electrode placement in unilateral impairment. 55 young children with cerebral palsy across all functional ability levels were included. Height/length was measured or estimated from knee height. Total body water was estimated using a Bodystat 1500MDD and three equations, and measured using the gold standard, deuterium dilution technique. Comparisons were made using Bland Altman analysis. For children with bilateral impairment, the Fjeld equation estimated total body water with the least bias (limits of agreement): 0.0 L (-1.4 L to 1.5 L); the Pencharz equation produced the greatest: 2.7 L (0.6 L-4.8 L). For children with unilateral impairment, differences between measured and estimated total body water were lowest on the unimpaired side using the Fjeld equation 0.1 L (-1.5 L to 1.6 L)) and greatest for the Pencharz equation. The ability of bioelectrical impedance to estimate total body water depends on the equation chosen. The Fjeld equation was the most accurate for the group, however, individual results varied by up to 18%. A population specific equation was developed and may enhance the accuracy of estimates. Australian New Zealand Clinical Trials Registry (ANZCTR) number: ACTRN12611000616976. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  2. Whole-body impedance--what does it measure?

    PubMed

    Foster, K R; Lukaski, H C

    1996-09-01

    Although the bioelectrical impedance technique is widely used in human nutrition and clinical research, an integrated summary of the biophysical and bioelectrical bases of this approach is lacking. We summarize the pertinent electrical phenomena relevant to the application of the impedance technique in vivo and discuss the relations between electrical measurements and biological conductor volumes. Key terms in the derivation of bioelectrical impedance analysis are described and the relation between the electrical properties of tissues and tissue structure is discussed. The relation between the impedance of an object and its geometry, scale, and intrinsic electrical properties is also discussed. Correlations between whole-body impedance measurements and various bioconductor volumes, such as total body water and fat-free mass, are experimentally well established; however, the reason for the success of the impedence technique is much less clear. The bioengineering basis for the technique is critically presented and considerations are proposed that might help to clarify the method and potentially improve its sensitivity.

  3. Drug and bioactive molecule screening based on a bioelectrical impedance cell culture platform

    PubMed Central

    Ramasamy, Sakthivel; Bennet, Devasier; Kim, Sanghyo

    2014-01-01

    This review will present a brief discussion on the recent advancements of bioelectrical impedance cell-based biosensors, especially the electric cell-substrate impedance sensing (ECIS) system for screening of various bioactive molecules. The different technical integrations of various chip types, working principles, measurement systems, and applications for drug targeting of molecules in cells are highlighted in this paper. Screening of bioactive molecules based on electric cell-substrate impedance sensing is a trial-and-error process toward the development of therapeutically active agents for drug discovery and therapeutics. In general, bioactive molecule screening can be used to identify active molecular targets for various diseases and toxicity at the cellular level with nanoscale resolution. In the innovation and screening of new drugs or bioactive molecules, the activeness, the efficacy of the compound, and safety in biological systems are the main concerns on which determination of drug candidates is based. Further, drug discovery and screening of compounds are often performed in cell-based test systems in order to reduce costs and save time. Moreover, this system can provide more relevant results in in vivo studies, as well as high-throughput drug screening for various diseases during the early stages of drug discovery. Recently, MEMS technologies and integration with image detection techniques have been employed successfully. These new technologies and their possible ongoing transformations are addressed. Select reports are outlined, and not all the work that has been performed in the field of drug screening and development is covered. PMID:25525360

  4. The Effect of an Acute After-School Exercise Bout on Percentage of Body Fat Using Leg-to-Leg Bioelectrical Impedance Analysis in Children

    ERIC Educational Resources Information Center

    Andreacci, Joseph L.; Dixon, Curt B.; Rompolski, Krista; VanGorden, Kelly M.

    2008-01-01

    Bioelectrical impedance analysis (BIA) is a fast, easy to administer, and relatively inexpensive method of evaluating body composition. Due to the ease of operation, interest in using BIA to estimate percentage of body fat (%BF) has grown, especially in settings where body composition assessments are often performed without the benefit of…

  5. Does bioelectrical impedance analysis accurately estimate the condition of threatened and endangered desert fish species?

    USGS Publications Warehouse

    Dibble, Kimberly L.; Yard, Micheal D.; Ward, David L.; Yackulic, Charles B.

    2017-01-01

    Bioelectrical impedance analysis (BIA) is a nonlethal tool with which to estimate the physiological condition of animals that has potential value in research on endangered species. However, the effectiveness of BIA varies by species, the methodology continues to be refined, and incidental mortality rates are unknown. Under laboratory conditions we tested the value of using BIA in addition to morphological measurements such as total length and wet mass to estimate proximate composition (lipid, protein, ash, water, dry mass, energy density) in the endangered Humpback Chub Gila cypha and Bonytail G. elegans and the species of concern Roundtail Chub G. robusta and conducted separate trials to estimate the mortality rates of these sensitive species. Although Humpback and Roundtail Chub exhibited no or low mortality in response to taking BIA measurements versus handling for length and wet-mass measurements, Bonytails exhibited 14% and 47% mortality in the BIA and handling experiments, respectively, indicating that survival following stress is species specific. Derived BIA measurements were included in the best models for most proximate components; however, the added value of BIA as a predictor was marginal except in the absence of accurate wet-mass data. Bioelectrical impedance analysis improved the R2 of the best percentage-based models by no more than 4% relative to models based on morphology. Simulated field conditions indicated that BIA models became increasingly better than morphometric models at estimating proximate composition as the observation error around wet-mass measurements increased. However, since the overall proportion of variance explained by percentage-based models was low and BIA was mostly a redundant predictor, we caution against the use of BIA in field applications for these sensitive fish species.

  6. [Resting metabolic rate estimated by bioelectrical impedance analysis and its determinants in maintenance hemodialysis patients].

    PubMed

    Da, J J; Peng, H Y; Lin, X; Shen, Y; Zhao, J Q; He, S; Zha, Y

    2018-03-27

    Objective: To explore the level of resting energy expenditure (REE) estimated by bioelectrical impedance analysis and the association of resting metabolic rate (RMR) with clinical related factors, and provide new ideas for improving protein energy wasting (PEW) in maintenance hemodialysis (MHD) patients. Methods: Seven hundred and sixty-five subjects receiving MHD between July 2015 and September 2016 in 11 hemodialysis centers in Guizhou province were enrolled in this cross-sectional study. Bioelectrical impedance analysis was used to measure RMR and body composition, such as lean body mass, fat mass and body cell mass (BCM). Baseline characteristics, routine blood test indexes and biochemical data of hemodialysis patients were collected. The level of RMR and body composition in hemodialysis patients was compared by gender grouping. Then the patients were divided into four groups according to the cutoff value of RMR quartile. Spearman correlation analysis and multiple linear regression analysis were used to analyze the relationships between RMR and clinical related factors. Results: The average age of MHD patients was (54.96±15.78) years and the duriation of dialysis was (42.3±9.0) months. The level of RMR in male patients (474 cases, 61.96%) was significantly higher than that in female patients [1 591(1 444, 1 764) kcal/d vs 1 226 (1 104, 1 354) kcal/d, P <0.001]. However, this significant difference of RMR between different genders disappeared after adjusting for lean body mass ( P =0.193). Multiple linear regression analysis showed that RMR was positively correlated with body surface area (β=0.817) and lactate dehydrogenase (LDH) (β=0.198), and negatively correlated with age (β=-0.141), all P <0.05. Conclusion: RMR levels in patients with maintenance hemodialysis are associated with lactate dehydrogenase level, which may become a new index to evaluate energy consumption.

  7. Assessment of fat-free mass from bioelectrical impedance analysis in obese women with Prader-Willi syndrome.

    PubMed

    Bedogni, Giorgio; Grugni, Graziano; Tringali, Gabriella; Agosti, Fiorenza; Sartorio, Alessandro

    2015-01-01

    Fat-free mass (FFM) is lower in obese subjects with Prader-Willi syndrome (PWS) than in obese subjects without PWS. FFM prediction equations developed in non-PWS subjects may, thus, not work in PWS subjects. To test whether the estimation of FFM from bioelectrical impedance analysis (BIA) in PWS subjects requires population-specific equations. Using dual-energy X-ray absorptiometry, this study measured FFM in 27 PWS and 56 non-PWS obese women and evaluated its association with the impedance index at 50 kHz (ZI50), i.e. the ratio between squared height and whole-body impedance at 50 kHz. At the same level of ZI50, PWS women had a lower FFM than non-PWS women. However, when PWS-specific equations were used, FFM was accurately estimated at the population level. An equation employing a dummy variable coding for PWS status was able to explain 85% of the variance of FFM with a root mean squared error of 3.3 kg in the pooled sample (n = 83). Population-specific equations are needed to estimate FFM from BIA in obese PWS women.

  8. Impact of eating and drinking on body composition measurements by bioelectrical impedance.

    PubMed

    Androutsos, O; Gerasimidis, K; Karanikolou, A; Reilly, J J; Edwards, C A

    2015-04-01

    Bioelectrical impedance analysis would be a more practical tool to measure body composition in clinical settings, dietetic practice and epidemiological studies if patients/subjects did not have to fast before measurements. The present study assessed whether the ingestion of food or drink had any biologically significant effect on bioimpedance measurements and body composition by the foot-to-foot method. Fifty-five healthy adults [30 males and 25 females; mean (SD) age 27.7 (7.1) years; mean (SD)body mass index 24 (3.8) kg m(-2)] were randomly assigned to a 2-day food trial (high-fat meal or high-carbohydrate meal) or a 2-day drink trial (water or high electrolyte drink). Body composition measurements were carried out in the fasting state, immediately after meal consumption and every 30 min for 2 h by the foot-to-foot single frequency bioimpedance technique. Bioimpedance increased significantly after the ingestion of food and fluid, although the changes were small. The electrolyte drink, high-fat and high-carbohydrate meals significantly increased the percentage body fat and fat mass. In all cases, the median percentage changes from baseline were approximately 1% in body fat percentage units. Although there were statistically significant changes in body composition estimates after food or drink consumption, these were small and within the imprecision of the impedance technique, and so are unlikely to be of clinical significance. The present study suggests that impedance measures of body fatness in clinical settings do not require strict adherence to fasting, and this should increase the opportunities for clinical application. © 2014 The British Dietetic Association Ltd.

  9. The relationship between nocturnal polyuria and the distribution of body fluid: assessment by bioelectric impedance analysis.

    PubMed

    Torimoto, Kazumasa; Hirayama, Akihide; Samma, Shoji; Yoshida, Katsunori; Fujimoto, Kiyohide; Hirao, Yoshihiko

    2009-01-01

    Increased nocturnal urinary volume is closely associated with nocturia. We investigated the relationship between nocturnal polyuria and the variation of body fluid distribution during the daytime using bioelectric impedance analysis. A total of 34 men older than 60 years were enrolled in this study. A frequency volume chart was recorded. Nocturnal polyuria was defined as a nocturnal urine volume per 24-hour production of greater than 0.35 (the nocturnal polyuria index). Bioelectric impedance analysis was performed 4 times daily at 8 and 11 a.m., and 5 and 9 p.m. using an InBody S20 body composition analyzer (BioSpace, Seoul, Korea). A significant difference was found in mean +/- SEM 24-hour urine production per fat-free mass between the groups with and without nocturnal polyuria (17.8 +/- 1.4 vs 7.7 +/- 0.9 ml/kg). The increase in fluid in the legs compared with the volume at 8 a.m. was significantly larger at 5 p.m., while there was no difference in the arms or trunk. Nocturnal urine volume significantly correlated with the difference in fluid volume in the legs (r = 0.527, p = 0.0019) and extracellular fluid volume (r = 0.3844, p = 0.0248) between the volumes at 8 a.m. and 9 p.m. Overproduction of urine per fat-free mass leads to nocturnal polyuria. Extracellular fluid accumulates as edema in the legs during the day in patients with nocturnal polyuria. The volume of accumulated extracellular fluid correlates with nocturnal urine volume. We suggest that leg edema is the source of nocturnal urine volume and decreasing edema may cure nocturnal polyuria.

  10. Foot-to-foot bioelectrical impedance analysis: a valuable tool for the measurement of body composition in children.

    PubMed

    Tyrrell, V J; Richards, G; Hofman, P; Gillies, G F; Robinson, E; Cutfield, W S

    2001-02-01

    To determine the accuracy of foot-to-foot bioelectrical impedance analysis (BIA) and anthropometric indices as measures of body composition in children. Comparison of foot-to-foot BIA and anthropometry to dual-energy X-ray absorptiometry (DEXA)-derived body composition in a multi-ethnic group of children. : Eighty-two European, NZ Maori and Pacific Island children aged 4.9-10.9 y. DEXA body composition, foot-to-foot bioelectrical impedance, height, weight, hip and waist measurements. Using a BIA prediction equation derived from our study population we found a high correlation between DEXA and BIA in the estimation of fat-free mass (FFM), fat mass (FM) and percentage body fat (PBF) (r=0.98, 0.98 and 0.94, respectively). BIA-FFM underestimated DEXA-FFM by a mean of 0.75 kg, BIA-FM overestimated DEXA-FM by a mean of 1.02 kg and BIA-PBF overestimated DEXA-PBF by a mean of 2.53%. The correlation between six anthropometric indices (body mass index (BMI), ponderal index, Chinn's weight-for-height index, BMI standard deviation score, weight-for-length index and Cole's weight-for-height index) and DEXA were also examined. The correlation of these indices with PBF was remarkably similar (r=0.85-0.87), more variable with FM (r=0.77-0.94) and poor with FFM (r=0.41-0.75). BIA correlated better than anthropometric indices in the estimation of FFM, FM and PBF. Foot-to-foot BIA is an accurate technique in the measurement of body composition.

  11. Reliability and concurrent validity of Futrex and bioelectrical impedance.

    PubMed

    Vehrs, P; Morrow, J R; Butte, N

    1998-11-01

    Thirty Caucasian males (aged 19-32yr) participated in this study designed to investigate the reliability of multiple bioelectrical impedance analysis (BIA) and near-infrared spectroscopy (Futrex, FTX) measurements and the validity of BIA and FTX estimations of hydrostatically (UW) determined percent body fat (%BF). Two BIA and two FTX instruments were used to make 6 measurements each of resistance (R) and optical density (OD) respectively over a 30 min period on two consecutive days. Repeated measures ANOVA indicated that FTX and BIA, using manufacturer's equations, significantly (p<0.01) under predicted UW by 2.4 and 3.8%BF respectively. Standard error of estimate (SEE) and total error (TE) terms provided by regression analysis for FTX (4.6 and 5.31%BF respectively) and BIA (5.65 and 6.95%BF, respectively) were high. Dependent t-tests revealed no significant differences in either FTX or BIA predictions of %BF using two machines. Intraclass reliabilities for BIA and FTX estimates of UW %BF across trials, days, and machines all exceeded 0.97. A significant random error term associated with FTX and a significant subject-by-day interaction associated with BIA was revealed using the generalizability model. Although FTX and BIA estimates of UW %BF were reliable, due to the significant underestimation of UW %BF and high SEE and TE, neither FTX nor BIA were considered valid estimates of hydrostatically determined %BF.

  12. Body composition of collegiate football players: bioelectrical impedance and skinfolds compared to hydrostatic weighing.

    PubMed

    Oppliger, R A; Nielsen, D H; Shetler, A C; Crowley, E T; Albright, J P

    1992-01-01

    The need for simple, valid techniques of body composition assessment among athletes is a growing concern of the physical therapist. This paper reports on several common methods applied to university football players. Body composition analysis was conducted on 28 Division IA football players using three different bioelectrical impedance analysis (BIA) systems, skinfolds (SF), and hydrostatic weighing (HYDRO). Correlations for all methods with HYDRO were high (>.88), but BIA significantly overpredicted body fatness. In contrast, three SF equations showed small differences with HYDRO and reasonable measurement error. Clinicians should exercise caution when using BIA based on the existing manufacturers' equations with athletic populations. Adjustments to BIA regression equations by including modifying or anthropometric variables could enhance the predictive accuracy of these methods with lean, athletic males. J Orthop Sports Phys Ther 1992;15(4):187-192.

  13. [Assessing nutritional status of severe malnutrition patients by bioelectrical impedance technique: a multicenter prospective study].

    PubMed

    Li, Qiang; Li, Xueni; Leng, Yuxin; Zhu, Xi; Yao, Gaiqi

    2018-02-01

    To assess the nutritional status of severe malnutrition patients with anorexia nervosa by multi-frequency bioelectrical impedance technique, and to provide the basis for nutritional support therapy. A prospective study was conducted. Twenty-six severe malnutrition patients with anorexia nervosa, body mass index (BMI) ≤ 16 kg/m 2 admitted to intensive care unit (ICU) of Peking University Third Hospital and general three ward of Peking University Sixth Hospital from June 1st to September 30th, 2017 were enrolled. The extracellular water (ECW), intracellular water (ICW), ECW/ICW ratio, adipose tissue mass (ATM), lean tissue mass (LTM), total body water/body weight (TBW/WT), ATM/WT, and LTM/WT were measured by multi-frequency bioelectrical impedance meter. Thirty-eighty healthy volunteers with normal nutritional status (23.0 kg/m 2 > BMI > 18.5 kg/m 2 ) matched by gender and height were enrolled as healthy control group. The predictive value of main body composition for nutritional status were analyzed by receiver operating characteristic (ROC) curve. All the patients were female. There was no significant difference in height between two groups, but WT and BMI in the severe malnutrition group were significantly higher than those in the healthy control group [WT (kg): 38.1±4.9 vs. 54.2±3.3, BMI (kg/m 2 ): 13.6±2.5 vs. 21.2±1.1, both P < 0.01]. Compared with the healthy control group, the ECW, ICW, ATM, LTM, ATM/WT and LTM/WT were significantly decreased in the severe malnutrition group [ECW (L): 9.02±0.42 vs. 10.19±0.77, ICW (L): 12.6±0.9 vs.19.1±1.3, ATM (kg): 9.3±1.1 vs. 16.6±1.9, LTM (kg): 16.5±1.5 vs. 26.1±1.7, ATM/WT: 0.26±0.02 vs. 0.30±0.02, LTM/WT: 0.22±0.02 vs. 0.26±0.01, all P < 0.01], the ECW/ICW and TBW/WT were significantly increased in the severe malnutrition group (ECW/ICW: 0.72±0.06 vs. 0.54±0.06, TBW/WT: 0.58±0.02 vs. 0.52±0.02, both P < 0.01). It was shown by ROC curve analysis that the area under ROC curve (AUC) of TBW/WT, ATM

  14. Nutritional status and body composition by bioelectrical impedance vector analysis: A cross sectional study in mild cognitive impairment and Alzheimer's disease.

    PubMed

    Cova, Ilaria; Pomati, Simone; Maggiore, Laura; Forcella, Marica; Cucumo, Valentina; Ghiretti, Roberta; Grande, Giulia; Muzio, Fulvio; Mariani, Claudio

    2017-01-01

    Analysis of nutritional status and body composition in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). A cross-sectional study was performed in a University-Hospital setting, recruiting 59 patients with AD, 34 subjects with MCI and 58 elderly healthy controls (HC). Nutritional status was assessed by anthropometric parameters (body mass index; calf, upper arm and waist circumferences), Mini Nutritional Assessment (MNA) and body composition by bioelectrical impedance vector analysis (BIVA). Variables were analyzed by analysis of variance and subjects were grouped by cognitive status and gender. Sociodemographic variables did not differ among the three groups (AD, MCI and HC), except for females' age, which was therefore used as covariate in a general linear multivariate model. MNA score was significantly lower in AD patients than in HC; MCI subjects achieved intermediate scores. AD patients (both sexes) had significantly (p<0.05) higher height-normalized impedance values and lower phase angles (body cell mass) compared with HC; a higher ratio of impedance to height was found in men with MCI with respect to HC. With BIVA method, MCI subjects showed a significant displacement on the RXc graph on the right side indicating lower soft tissues (Hotelling's T2 test: men = 10.6; women = 7.9;p < 0,05) just like AD patients (Hotelling's T2 test: men = 18.2; women = 16.9; p<0,001). Bioelectrical parameters significantly differ from MCI and AD to HC; MCI showed an intermediate pattern between AD and HC. Longitudinal studies are required to investigate if BIVA could reflect early AD-changes in body composition in subjects with MCI.

  15. Bioelectrical impedance vector analysis as a useful predictor of nutritional status in patients with short bowel syndrome.

    PubMed

    Fassini, Priscila Giacomo; Nicoletti, Carolina Ferreira; Pfrimer, Karina; Nonino, Carla Barbosa; Marchini, Júlio Sérgio; Ferriolli, Eduardo

    2017-08-01

    Short bowel syndrome (SBS) represents a serious intestinal absorption disorder. Therefore, patients with SBS may have severe malnutrition and excessive mineral and fluid losses. Once the assessment of nutritional status is important in their follow-up, body composition measurements and especially total body water (TBW) must be repeatedly evaluated for the assessment of changes in hydration and nutritional care. The aim of this study was to investigate if bioelectrical impedance vector analysis (BIVA) is a useful predictor of nutritional and hydration status in SBS patients. In this observational study, 22 participants (12 women), 11 with SBS and 11 gender, age and BMI-matched controls, were evaluated using the bioelectrical impedance measurements (BIA) and BIVA to assess nutritional and hydration status. Participants age was 53 ± 8 y (mean ± SD). Body water, fat mass and lean mass as assessed by BIA did not differ between the two groups. However, BIVA showed important differences between the groups regarding hydration and amount of soft tissue (p < 0.0001 for women and p = 0.0015 for men). The results also evidenced that women's vectors were related to cachexia, while men's vectors were divided into lean and cachexia quadrants. The use of BIVA analysis also evidenced hydration disturbance and losses of soft tissue. BIVA may represent a better predictor of nutritional status for analysis and interpretation of body composition in patients with short bowel syndrome. This trial was registered at ClinicalTrials.gov as NCT02113228. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  16. Stratification of fat-free mass index percentiles for body composition based on NHANES III bioelectric impedance data

    PubMed Central

    Kudsk, Kenneth A.; Munoz-del-Rio, Alejandro; Busch, Rebecca A.; Kight, Cassandra E.; Schoeller, Dale A.

    2015-01-01

    Background Loss of protein mass and lower fat-free mass index (FFMI) are associated with longer length of stay, post-surgical complications and other poor outcomes in hospitalized patients Normative data for FFMI of U.S. populations does not exist. This work aims to create a stratified FFMI percentile table for the U.S. population using the large bioelectric impedance analysis data obtained from National Health and Nutrition Examination Surveys (NHANES). Methods Fat-free mass (FFM) was calculated from the NHANES III bioelectric impedance analysis and anthropometric data for males and females ages 12 to over 90 years for three race-ethnicities (non-Hispanic white, non-Hispanic black, and Mexican-American). FFM was normalized by subject height to create a FFMI distribution table for the U.S. population. Selected percentiles were obtained by age, sex, and race-ethnicity. Data was collapsed by race-ethnicity before and after removing obese and underweight subjects to create a FFMI decile table for males and females aged 12 and over for the healthy weight U.S. population. Results FFMI increased during adolescent growth but stabilized in the early 20s. The FFMI deciles were similar by race-ethnicity and age group remaining relatively stable between ages of 22 and 80 years. The FFMI deciles for males and females were significantly different. Conclusions After eliminating the obese and extremely thin, FFMI percentiles remain stable during adult years allowing creation of age- and race/ethnicity-independent decile tables for males and females. These tables allow stratification of individuals for nutrition intervention trials to depict changing nutrition status during medical, surgical and nutritional interventions. PMID:26092851

  17. Discordance between bioelectrical impedance vector analysis and the new ESPEN definition of malnutrition for the diagnosis of hospital malnutrition.

    PubMed

    Dehesa-López, Edgar; Martínez-Felix, Jesús Israel; Ruiz-Ramos, Arturo; Atilano-Carsi, Ximena

    2017-04-01

    No universally accepted diagnostic criteria for malnutrition are available to date. The aim was to assess the concordance for the diagnosis of hospital malnutrition between the bioelectrical impedance vector analysis (BIVA) and the new definition of malnutrition proposed by the European Society for Clinical Nutrition and Metabolism (ESPEN). A total of 140 adult hospitalized patients were included. The malnutrition risk was assessed by the Nutritional Risk Screening. The ESPEN malnutrition criteria (body mass index (BMI) <18.5 kg/m 2 , weight loss (WL) + low BMI, and WL + low fat free mass index (FFMI) were applied to each patient. The bioelectrical impedance of each patient was measured, and malnutrition was diagnosed using the BIVA method. Diagnostic concordance between the BIVA and the new ESPEN definition was assessed with the Kappa coefficient. The malnutrition prevalence was higher with the BIVA vs ESPEN definition (22.1% vs 13.6%) in the global population and was similar (12.8% vs 12.1%) in the population at risk of malnutrition. The diagnostic performance of the BIVA was acceptable, with higher sensitivity in patients with fluid overload (FO) and more specificity in euvolemic patients. Diagnostic concordance between the BIVA and the ESPEN definition was poor for the global population (kappa = 0.56) and the population at risk of malnutrition (kappa = 0.67) but was acceptable in patients with FO (kappa = 0.78). However, the discordant BIVA+/ESPEN- patients classified as false positives for BIVA showed clinical and body composition data (low FFMI, low phase angle) consistent with malnutrition. According to the clinical and bioelectrical characteristics of the discordant BIVA+/ESPEN- patients, the BIVA could perform better that the new ESPEN definition for the diagnosis of hospital malnutrition, which should be confirmed with other studies. Copyright © 2017 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights

  18. Practical human abdominal fat imaging utilizing electrical impedance tomography.

    PubMed

    Yamaguchi, T; Maki, K; Katashima, M

    2010-07-01

    The fundamental cause of metabolic syndrome is thought to be abdominal obesity. Accurate diagnosis of abdominal obesity can be done by an x-ray computed tomography (CT) scan. But CT is expensive, bulky and entails the risks involved with radiation. To overcome such disadvantages, we attempted to develop a measuring device that could apply electrical impedance tomography to abdominal fat imaging. The device has 32 electrodes that can be attached to a subject's abdomen by a pneumatic mechanism. That way, electrode position data can be acquired simultaneously. An applied alternating current of 1.0 mArms was used at a frequency of 500 kHz. Sensed voltage data were carefully filtered to remove noise and processed to satisfy the reciprocal theorem. The image reconstruction software was developed concurrently, applying standard finite element methods and the Marquardt method to solve the mathematical inverse problem. The results of preliminary experiments showed that abdominal subcutaneous fat and the muscle surrounding the viscera could be imaged in humans. While our imaging of visceral fat was not of sufficient quality, it was suggested that we will be able to develop a safe and practical abdominal fat scanner through future improvements.

  19. Effect of abdominal resistance exercise on abdominal subcutaneous fat of obese women: a randomized controlled trial using ultrasound imaging assessments.

    PubMed

    Kordi, Ramin; Dehghani, Saeed; Noormohammadpour, Pardis; Rostami, Mohsen; Mansournia, Mohammad Ali

    2015-01-01

    The aim of this study was to compare the effect of diet and an abdominal resistance training program to diet alone on abdominal subcutaneous fat thickness and waist circumference of overweight and obese women. This randomized clinical trial included 40 overweight and obese women randomly divided into 2 groups: diet only and diet combined with 12 weeks of abdominal resistance training. Waist and hip circumferences and abdominal skin folds of the subjects were measured at the beginning and 12 weeks after the interventions. In addition, abdominal subcutaneous fat thickness of the subjects was measured using ultrasonography. Percentage body fat and lean body mass of all the subjects were also measured using a bioelectric impedance device. After 12 weeks of intervention, the weight of participants in both groups decreased; but the difference between the 2 groups was not significant (P = .45). Similarly, other variables including abdominal subcutaneous fat, waist circumference, hip circumference, body mass index, body fat percentage, and skin fold thickness were reduced in both groups; but there were no significant differences between the groups. This study found that abdominal resistance training besides diet did not reduce abdominal subcutaneous fat thickness compared to diet alone in overweight or obese women. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  20. Abdominal fat thickness measurement using Focused Impedance Method (FIM) - phantom study

    NASA Astrophysics Data System (ADS)

    Haowlader, Salahuddin; Baig, Tanveer Noor; Siddique-e Rabbani, K.

    2010-04-01

    Abdominal fat thickness is a risk indicator of heart diseases, diabetes, etc., and its measurement is therefore important from the point of view of preventive care. Tetrapolar electrical impedance measurements (TPIM) could offer a simple and low cost alternative for such measurement compared to conventional techniques using CT scan and MRI, and has been tried by different groups. Focused Impedance Method (FIM) appears attractive as it can give localised information. An intuitive physical model was developed and experimental work was performed on a phantom designed to simulate abdominal subcutaneous fat layer in a body. TPIM measurements were performed with varying electrode separations. For small separations of current and potential electrodes, the measured impedance changed little, but started to decrease sharply beyond a certain separation, eventually diminishing gradually to negligible values. The finding could be explained using the intuitive physical model and gives an important practical information. TPIM and FIM may be useful for measurement of SFL thickness only if the electrode separations are within a certain specific range, and will fail to give reliable results if beyond this range. Further work, both analytical and experimental, are needed to establish this technique on a sound footing.

  1. Estimation of maximal oxygen uptake by bioelectrical impedance analysis.

    PubMed

    Stahn, Alexander; Terblanche, Elmarie; Grunert, Sven; Strobel, Günther

    2006-02-01

    Previous non-exercise models for the prediction of maximal oxygen uptake VO(2max) have failed to accurately discriminate cardiorespiratory fitness within large cohorts. The aim of the present study was to evaluate the feasibility of a completely indirect method for predicting VO(2max) that was based on bioelectrical impedance analysis (BIA) in 66 young, healthy fit men and women. Multiple, stepwise regression analysis was used to determine the usefulness of BIA and additional covariates to estimate VO(2max) (ml min(-1)). BIA was highly correlated to VO(2max) (r = 0.914; P < 0.001) and entered the regression equation first. The inclusion of gender and a physical activity rating further improved the model which accounted for 88% of the variance in VO(2max) and resulted in a relative standard error of the estimate (SEE) of 7.2%. Substantial agreement between the methods was confirmed by the fact that nearly all the differences were within +/-2 SD. Furthermore, in contrast to previously published non-exercise models, no trend of a reduction in prediction accuracy with increasing VO(2max) values was apparent. It was concluded that a non-exercise model based on BIA might be a rapid and useful technique to estimate VO(2max), when a direct test does not seem feasible. However, though the present results are useful to determine the viability of the method, further refinement of the BIA approach and its validation in a large, diverse population is needed before it can be applied to the clinical and epidemiological settings.

  2. Validation of bioelectrical-impedance analysis as a measurement of change in body composition in obesity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kushner, R.F.; Kunigk, A.; Alspaugh, M.

    1990-08-01

    The bioelectrical-impedance-analysis (BIA) method accurately measures body composition in weight-stable subjects. This study validates the use of BIA to measure change in body composition. Twelve obese females underwent weight loss at a mean rate of 1.16 kg/wk. Body composition was measured by deuterium oxide dilution (D2O), BIA, and skinfold anthropometry (SFA) at baseline and at 5% decrements in weight. Highly significant correlations were obtained between D2O and BIA (r = 0.971) and between D2O and SFA (r = 0.932). Overall, BIA predicted change in fat-free mass with greater accuracy (to 0.4 kg) and precision (+/- 1.28 kg) than did anthropometrymore » (to 0.8 kg and +/- 2.58 kg, respectively). We conclude that BIA is a useful clinical method for measuring change in body composition.« less

  3. Urinary Creatinine Excretion, Bioelectrical Impedance Analysis, and Clinical Outcomes in Patients with CKD: The CRIC Study

    PubMed Central

    Xie, Dawei; Anderson, Amanda H.; Leonard, Mary B.; Reese, Peter P.; Delafontaine, Patrice; Horwitz, Edward; Kallem, Radhakrishna; Navaneethan, Sankar; Ojo, Akinlolu; Porter, Anna C.; Sondheimer, James H.; Sweeney, H. Lee; Townsend, Raymond R.; Feldman, Harold I.

    2014-01-01

    Background and objectives Previous studies in chronic disease states have demonstrated an association between lower urinary creatinine excretion (UCr) and increased mortality, a finding presumed to reflect the effect of low muscle mass on clinical outcomes. Little is known about the relationship between UCr and other measures of body composition in terms of the ability to predict outcomes of interest. Design, setting, participants, & measurements Using data from the Chronic Renal Insufficiency Cohort (CRIC), the relationship between UCr, fat free mass (FFM) as estimated by bioelectrical impedance analysis, and (in a subpopulation) whole-body dual-energy x-ray absorptiometry assessment of appendicular lean mass were characterized. The associations of UCr and FFM with mortality and ESRD were compared using Cox proportional hazards models. Results A total of 3604 CRIC participants (91% of the full CRIC cohort) with both a baseline UCr and FFM measurement were included; of these, 232 had contemporaneous dual-energy x-ray absorptiometry measurements. Participants were recruited between July 2003 and March 2007. UCr and FFM were modestly correlated (rho=0.50; P<0.001), while FFM and appendicular lean mass were highly correlated (rho=0.91; P<0.001). Higher urinary urea nitrogen, black race, younger age, and lower serum cystatin C level were all significantly associated with higher UCr. Over a median (interquartile range) of 4.2 (3.1–5.0) years of follow-up, 336 (9.3%) participants died and 510 (14.2%) reached ESRD. Lower UCr was associated with death and ESRD even after adjustment for FFM (adjusted hazard ratio for death per 1 SD higher level of UCr, 0.63 [95% confidence interval, 0.56 to 0.72]; adjusted hazard ratio for ESRD per 1 SD higher level of UCr, 0.70 [95% confidence interval, 0.63 to 0.75]). Conclusions Among a cohort of individuals with CKD, lower UCr is associated with death and ESRD independent of FFM as assessed by bioelectrical impedance analysis. PMID

  4. Application of bioelectrical impedance analysis in prediction of light kid carcass and muscle chemical composition.

    PubMed

    Silva, S R; Afonso, J; Monteiro, A; Morais, R; Cabo, A; Batista, A C; Guedes, C M; Teixeira, A

    2018-06-01

    Carcass data were collected from 24 kids (average live weight of 12.5±5.5 kg; range 4.5 to 22.4 kg) of Jarmelista Portuguese native breed, to evaluate bioelectrical impedance analysis (BIA) as a technique for prediction of light kid carcass and muscle chemical composition. Resistance (Rs, Ω) and reactance (Xc, Ω), were measured in the cold carcasses with a single frequency bioelectrical impedance analyzer and, together with impedance (Z, Ω), two electrical volume measurements (VolA and VolB, cm2/Ω), carcass cold weight (CCW), carcass compactness and several carcass linear measurements were fitted as independent variables to predict carcass composition by stepwise regression analysis. The amount of variation explained by VolA and VolB only reached a significant level (P<0.01 and P<0.05, respectively) for muscle weight, moisture, protein and fat-free soft tissue content, even so with low accuracy, with VolA providing the best results (0.326⩽R 2⩽0.366). Quite differently, individual BIA parameters (Rs, Xc and Z) explained a very large amount of variation in dissectible carcass fat weight (0.814⩽R 2⩽0.862; P<0.01). These individual BIA parameters also explained a large amount of variation in subcutaneous and intermuscular fat weights (respectively 0.749⩽R 2⩽0.793 and 0.718⩽R 2⩽0.760; P<0.01), and in muscle chemical fat weight (0.663⩽R 2⩽0.684; P<0.01). Still significant but much lower was the variation in muscle, moisture, protein and fat-free soft tissue weights (0.344⩽R 2⩽0.393; P<0.01) explained by BIA parameters. Still, the best models for estimation of muscle, moisture, protein and fat-free soft tissue weights included Rs in addition to CCW, and accounted for 97.1% to 99.8% (P<0.01) of the variation observed, with CCW by itself accounting for 97.0% to 99.6% (P<0.01) of that variation. Resistance was the only independent variable selected for the best model predicting subcutaneous fat weight. It was also selected for the best models

  5. Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis

    PubMed Central

    Tint, Mya-Thway; Ward, Leigh C; Soh, Shu E; Aris, Izzuddin M; Chinnadurai, Amutha; Saw, Seang Mei; Gluckman, Peter D; Godfrey, Keith M; Chong, Yap-Seng; Kramer, Michael S; Yap, Fabian; Lingwood, Barbara; Lee, Yung Seng

    2016-01-01

    The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in independent Western cohort. A total of 173 neonates at birth and 140 at week-2 of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations were assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week-2 but not at birth. Compared to the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0.01kg with 2SD limits of agreement (LOA) (0.18, −0.20). Prediction explained 88.9% of variation but not beyond that of anthropometry. Applying these equations to Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared to simple anthropometry in Asian populations. There is a need for population and age appropriate FFM prediction equations. PMID:26856420

  6. The Stayhealthy bioelectrical impedance analyzer predicts body fat in children and adults.

    PubMed

    Erceg, David N; Dieli-Conwright, Christina M; Rossuello, Amerigo E; Jensky, Nicole E; Sun, Stephanie; Schroeder, E Todd

    2010-05-01

    Bioelectrical impedance analysis (BIA) is a time-efficient and cost-effective method for estimating body composition. We hypothesized that there would be no significant difference between the Stayhealthy BC1 BIA and the selected reference methods when determining body composition. Thus, the purpose of the present study was to determine the validity of estimating percent body fat (%BF) using the Stayhealthy BIA with its most recently updated algorithms compared to the reference methods of dual-energy x-ray absorptiometry for adults and hydrostatic weighing for children. We measured %BF in 245 adults aged 18 to 80 years and 115 children aged 10 to 17 years. Body fat by BIA was determined using a single 50 kHz frequency handheld impedance device and proprietary software. Agreement between BIA and reference methods was assessed by Bland and Altman plots. Bland and Altman analysis for men, women, and children revealed good agreement between the reference methods and BIA. There was no significant difference by t tests between mean %BF by BIA for men, women, or children when compared to the respective reference method. Significant correlation values between BIA, and reference methods for all men, women, and children were 0.85, 0.88, and 0.79, respectively. Reliability (test-retest) was assessed by intraclass correlation coefficient and coefficient of variation. Intraclass correlation coefficient values were greater than 0.99 (P < .001) for men, women, and children with coefficient of variation values 3.3%, 1.8%, and 1.7%, respectively. The Stayhealthy BIA device demonstrated good agreement between reference methods using Bland and Altman analyses. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis.

    PubMed

    Tint, Mya-Thway; Ward, Leigh C; Soh, Shu E; Aris, Izzuddin M; Chinnadurai, Amutha; Saw, Seang Mei; Gluckman, Peter D; Godfrey, Keith M; Chong, Yap-Seng; Kramer, Michael S; Yap, Fabian; Lingwood, Barbara; Lee, Yung Seng

    2016-03-28

    The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air-displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in an independent Western cohort. A total of 173 neonates at birth and 140 at two weeks of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable, and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations was assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week two but not at birth. Compared with the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0·01 kg with 2 sd limits of agreement (LOA) (0·18, -0·20). Prediction explained 88·9 % of variation but not beyond that of anthropometry. Applying these equations to the Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared with simple anthropometry in Asian populations. There is a need for population- and age-appropriate FFM prediction equations.

  8. Estimation of total body water from bioelectrical impedance spectroscopy in oncology outpatients receiving radiotherapy and agreement with three prediction equations.

    PubMed

    Isenring, E; Colombo, M; Cross, G; Kellett, E; Swaney, L

    2009-02-01

    Bioelectrical impedance spectroscopy (BIS) may be more accurate in determining total body water (TBW) than bioelectrical impedance analysis (BIA). The present study compared the agreement between three TBW prediction equations developed using BIA and BIS-derived TBW in oncology outpatients. A cross-sectional, observational study was conducted in 37 outpatients receiving radiotherapy (27 males/10 females, aged 68.3 +/- 10.2 years). TBW was estimated by BIS (TBW(BIS)) and three BIA TBW prediction equations (TBW(ca-u): underweight cancer patients; TBW(ca-n): normal-weight cancer patients; and TBW(rad): patients receiving radiotherapy). Bland-Altman analyses determined agreement between methods. BIS-derived TBW using new resistivity constants was calculated. The mean +/- SD of TBW estimated by BIS was 39.8 +/- 8.3 L, which was significantly different from the prediction equations; TBW(rad) 35.1 +/- 7.9 L, TBW(ca-u) 33.1 +/- 7.5 L and TBW(ca-n) 32.3 +/- 7.3 L, (P < 0.001). Using new resistivity constants, TBW was 36.2 +/- 8.1 L but this still differed from the equations (P < 0.001). Bias between TBW(BIS) and that predicted by the equations was in the range 4.7-7.4 L or 1.1-3.9 L using new resistivity constants. TBW estimated by BIS cannot be directly compared with oncology-specific BIA equations, suggesting that BIS cannot be used at the group level in outpatients receiving radiotherapy. There was a reduced bias with BIS using new resistivity constants; however, further research should determine any advantage of BIS over BIA in this population.

  9. Bioelectrical impedance methods in clinical research: a follow-up to the NIH Technology Assessment Conference.

    PubMed

    Ellis, K J; Bell, S J; Chertow, G M; Chumlea, W C; Knox, T A; Kotler, D P; Lukaski, H C; Schoeller, D A

    1999-01-01

    In 1994, the National Institutes of Health (NIH) convened a Technology Assessment Conference "to provide physicians with a responsible assessment of bioelectrical impedance analysis (BIA) technology for body composition measurement." In 1997, Serono Symposia USA, Inc., organized an invited panel of scientists and clinicians, with extensive research and clinical experience with BIA, to provide an update. Panel members presented reviews based on their own work and published studies for the intervening years. Updates were provided on the single and multifrequency BIA methods and models; continued clinical research experiences; efforts toward establishing population reference norms; and the feasibility of establishing guidelines for potential diagnostic use of BIA in a clinical setting. This report provides a summary of the panel's findings including a consensus on several technical and clinical issues related to the research use of BIA, and those areas that are still in need of additional study.

  10. Feasibility and acceptability of a self-measurement using a portable bioelectrical impedance analysis, by the patient with chronic heart failure, in acute decompensated heart failure.

    PubMed

    Huguel, Benjamin; Vaugrenard, Thibaud; Saby, Ludivine; Benhamou, Lionel; Arméro, Sébastien; Camilleri, Élise; Langar, Aida; Alitta, Quentin; Grino, Michel; Retornaz, Frédérique

    2018-06-01

    Chronic heart failure (CHF) is a major public health matter. Mainly affecting the elderly, it is responsible for a high rate of hospitalization due to the frequency of acute heart failure (ADHF). This represents a disabling pathology for the patient and very costly for the health care system. Our study is designed to assess a connected and portable bioelectrical impedance analysis (BIA) that could reduce these hospitalizations by preventing early ADHF. This prospective study included patients hospitalized in cardiology for ADHF. Patients achieved 3 self-measurements using the BIA during their hospitalization and answered a questionnaire evaluating the acceptability of this self-measurement. The results of these measures were compared with the clinical, biological and echocardiographic criteria of patients at the same time. Twenty-three patients were included, the self-measurement during the overall duration of the hospitalization was conducted autonomously by more than 80% of the patients. The acceptability (90%) for the use of the portable BIA was excellent. Some correlations were statistically significant, such as the total water difference to the weight difference (p=0.001). There were common trends between the variation of impedance analysis measures and other evaluation criteria. The feasibility and acceptability of a self-measurement of bioelectrical impedance analysis by the patient in AHF opens up major prospects in the management of monitoring patients in CHF. The interest of this tool is the prevention of ADHF leading to hospitalization or re-hospitalizations now requires to be presented by new studies.

  11. Measurement of nutritional status in simulated microgravity by bioelectrical impedance spectroscopy

    NASA Technical Reports Server (NTRS)

    Bartok, Cynthia; Atkinson, Richard L.; Schoeller, Dale A.

    2003-01-01

    The potential of bioelectrical impedance spectroscopy (BIS) for assessing nutritional status in spaceflight was tested in two head-down-tilt bed-rest studies. BIS-predicted extracellular water (ECW), intracellular water (ICW), and total body water (TBW) measured using knee-elbow electrode placement were compared with deuterium and bromide dilution (DIL) volumes in healthy, 19- to 45-yr-old subjects. BIS was accurate during 44 h of head-down tilt with mean differences (BIS - DIL) of 0-0.1 kg for ECW, 0.3-0.5 for ICW, and 0.4-0.6 kg for TBW (n = 28). At 44 h, BIS followed the within-individual change in body water compartments with a relative prediction error (standard error of the estimate/baseline volume) of 2.0-3.6% of water space. In the second study, BIS did not detect an acute decrease (-1.41 +/- 0.91 kg) in ICW secondary to 48 h of a protein-free, 800 kcal/day diet (n = 18). BIS's insensitivity to ICW losses may be because they were predominantly (65%) localized to the trunk and/or because there was a general failure of BIS to measure ICW independently of ECW and TBW. BIS may have potential for measuring nutritional status during spaceflight, but its limitations in precision and insensitivity to acute ICW changes warrant further validation studies.

  12. Reference Centile Curves for Body Fat Percentage, Fat-free Mass, Muscle Mass and Bone Mass Measured by Bioelectrical Impedance in Asian Indian Children and Adolescents.

    PubMed

    Chiplonkar, Shashi; Kajale, Neha; Ekbote, Veena; Mandlik, Rubina; Parthasarathy, Lavanya; Borade, Ashwin; Patel, Pinal; Patel, Prerna; Khadilkar, Vaman; Khadilkar, Anuradha

    2017-12-15

    To create gender-specific percentile curves for percent body fat (%BF) by Bio electrical Impedance Analysis (BIA) for screening adiposity and risk of hypertension in Indian children and generate reference curves for percent fat-free mass (%FFM), muscle mass (%LM) and bone mineral content (BMC) by using bioelectrical impedance. Secondary analysis of data from previous multicenter cross-sectional studies. Private schools from five regions of India. A random sample of 3850 healthy school children (2067 boys) (5-17 yr) from private schools in five major Indian cities. Anthropometry, blood pressure (BP) and body composition were measured by bioelectrical impedance. Reference curves were generated by the LMS method. %BF, %FFM, %LM, BMC and BP. Median %BF increased by 6% from 5 to 13 years of age and declined (around 2%) up to 17 years in boys. In girls, %BF increased by 8% from 5 to 14 years and thereafter declined by 3%. Based upon the risk of hypertension, the new cut-offs of 75th and 85th percentile of %BF were proposed for detecting over fatness and excess fatness in children. Median %FFM was 90% at 5 yrs and decreased till 12 years, and then showed a slight increase to 84% at 17 yrs in boys. In girls, it was 86% at 5 yrs and decreased till 15 yrs, and plateaued at 71.8% at 17 yrs. Reference curves for percent body fat for Indian children would be useful to screen children for health risk in clinical set up.

  13. Ethnic Variability in Body Size, Proportions and Composition in Children Aged 5 to 11 Years: Is Ethnic-Specific Calibration of Bioelectrical Impedance Required?

    PubMed Central

    Lee, Simon; Bountziouka, Vassiliki; Lum, Sooky; Stocks, Janet; Bonner, Rachel; Naik, Mitesh; Fothergill, Helen; Wells, Jonathan C. K.

    2014-01-01

    Background Bioelectrical Impedance Analysis (BIA) has the potential to be used widely as a method of assessing body fatness and composition, both in clinical and community settings. BIA provides bioelectrical properties, such as whole-body impedance which ideally needs to be calibrated against a gold-standard method in order to provide accurate estimates of fat-free mass. UK studies in older children and adolescents have shown that, when used in multi-ethnic populations, calibration equations need to include ethnic-specific terms, but whether this holds true for younger children remains to be elucidated. The aims of this study were to examine ethnic differences in body size, proportions and composition in children aged 5 to 11 years, and to establish the extent to which such differences could influence BIA calibration. Methods In a multi-ethnic population of 2171 London primary school-children (47% boys; 34% White, 29% Black African/Caribbean, 25% South Asian, 12% Other) detailed anthropometric measurements were performed and ethnic differences in body size and proportion were assessed. Ethnic differences in fat-free mass, derived by deuterium dilution, were further evaluated in a subsample of the population (n = 698). Multiple linear regression models were used to calibrate BIA against deuterium dilution. Results In children <11 years of age, Black African/Caribbean children were significantly taller, heavier and had larger body size than children of other ethnicities. They also had larger waist and limb girths and relatively longer legs. Despite these differences, ethnic-specific terms did not contribute significantly to the BIA calibration equation (Fat-free mass = 1.12+0.71*(height2/impedance)+0.18*weight). Conclusion Although clear ethnic differences in body size, proportions and composition were evident in this population of young children aged 5 to 11 years, an ethnic-specific BIA calibration equation was not required. PMID:25478928

  14. Ethnic variability in body size, proportions and composition in children aged 5 to 11 years: is ethnic-specific calibration of bioelectrical impedance required?

    PubMed

    Lee, Simon; Bountziouka, Vassiliki; Lum, Sooky; Stocks, Janet; Bonner, Rachel; Naik, Mitesh; Fothergill, Helen; Wells, Jonathan C K

    2014-01-01

    Bioelectrical Impedance Analysis (BIA) has the potential to be used widely as a method of assessing body fatness and composition, both in clinical and community settings. BIA provides bioelectrical properties, such as whole-body impedance which ideally needs to be calibrated against a gold-standard method in order to provide accurate estimates of fat-free mass. UK studies in older children and adolescents have shown that, when used in multi-ethnic populations, calibration equations need to include ethnic-specific terms, but whether this holds true for younger children remains to be elucidated. The aims of this study were to examine ethnic differences in body size, proportions and composition in children aged 5 to 11 years, and to establish the extent to which such differences could influence BIA calibration. In a multi-ethnic population of 2171 London primary school-children (47% boys; 34% White, 29% Black African/Caribbean, 25% South Asian, 12% Other) detailed anthropometric measurements were performed and ethnic differences in body size and proportion were assessed. Ethnic differences in fat-free mass, derived by deuterium dilution, were further evaluated in a subsample of the population (n = 698). Multiple linear regression models were used to calibrate BIA against deuterium dilution. In children < 11 years of age, Black African/Caribbean children were significantly taller, heavier and had larger body size than children of other ethnicities. They also had larger waist and limb girths and relatively longer legs. Despite these differences, ethnic-specific terms did not contribute significantly to the BIA calibration equation (Fat-free mass = 1.12+0.71*(height2/impedance)+0.18*weight). Although clear ethnic differences in body size, proportions and composition were evident in this population of young children aged 5 to 11 years, an ethnic-specific BIA calibration equation was not required.

  15. Does intra-abdominal fluid increase the resting energy expenditure?

    PubMed

    Zarling, E J; Grande, A; Hano, J

    1997-10-01

    In patients with intra-abdominal fluid collection, caloric needs are based on an estimated dry weight. This is done because intra-abdominal fluid has been assumed to be metabolically inactive. One recent study of patients with slowly resolving ascites suggested otherwise. In our study, the effect of intra-abdominal fluid on the resting energy expenditure (REE) and apparent lean body mass was determined in 10 stable patients requiring peritoneal dialysis. For each subject, in both the empty and full state, we measured REE by indirect calorimetry, and body composition by the bioelectric impedance method. In the full state, the VCO2 was significantly increased (210 +/- 11 versus 197 +/- 9 mL/min, P < 0.02) compared with the empty state. This caused an increase in the calculated resting energy expenditure (1531 +/- 88 kcal/d empty versus 1593 +/- 94 kcal/d full, P < 0.05). The magnitude of increase in REE was similar to the expected calories derived from glucose absorbed out of the dialysate. Estimates of body fat, lean body mass, and total water also were not affected by the intra-abdominal fluid. We conclude that intra-abdominal fluid will not affect the measured REE and hence may be considered to be metabolically inactive.

  16. Stratification of Fat-Free Mass Index Percentiles for Body Composition Based on National Health and Nutrition Examination Survey III Bioelectric Impedance Data.

    PubMed

    Kudsk, Kenneth A; Munoz-Del-Rio, Alejandro; Busch, Rebecca A; Kight, Cassandra E; Schoeller, Dale A

    2017-02-01

    Loss of protein mass and lower fat-free mass index (FFMI) are associated with longer length of stay, postsurgical complications, and other poor outcomes in hospitalized patients. Normative data for FFMI of U.S. populations do not exist. This work aims to create a stratified FFMI percentile table for the U.S. population using the large bioelectric impedance analysis data obtained from National Health and Nutrition Examination Surveys (NHANES). Fat-free mass (FFM) was calculated from the NHANES III bioelectric impedance analysis and anthropometric data for males and females ages 12 to >90 years for 3 race/ethnicities (non-Hispanic white, non-Hispanic black, and Mexican American). FFM was normalized by subject height to create an FFMI distribution table for the U.S. Selected percentiles were obtained by age, sex, and race/ethnicity. Data were collapsed by race/ethnicity before and after removing obese and underweight participants to create an FFMI decile table for males and females 12 years and older for the healthy-weight U.S. FFMI increased during adolescent growth but stabilized in the early 20s. The FFMI deciles were similar by race/ethnicity, with age group remaining relatively stable between ages 25 and 80 years. The FFMI deciles for males and females were significantly different. After eliminating the obese and extremely thin, FFMI percentiles remain stable during adult years allowing creation of age- and race/ethnicity-independent decile tables for males and females. These tables allow stratification of individuals for nutrition intervention trials to depict changing nutrition status during medical, surgical, and nutrition interventions.

  17. Evaluation of multiple frequency bioelectrical impedance and Cole-Cole analysis for the assessment of body water volumes in healthy humans.

    PubMed

    Cornish, B H; Ward, L C; Thomas, B J; Jebb, S A; Elia, M

    1996-03-01

    To assess the application of a Cole-Cole analysis of multiple frequency bioelectrical impedance analysis (MFBIA) measurements to predict total body water (TBW) and extracellular water (ECW) in humans. This technique has previously been shown to produce accurate and reliable estimates in both normal and abnormal animals. The whole body impedance of 60 healthy humans was measured at 496 frequencies (ranging from 4 kHz to 1 MHz) and the impedance at zero frequency, Ro, and at the characteristic frequency, Zc, were determined from the impedance spectrum, (Cole-Cole plot). TBW and ECW were independently determined using deuterium and bromide tracer dilution techniques. At the Dunn Clinical Nutrition Centre and The Department of Biochemistry, University of Queensland. 60 healthy adult volunteers (27 men and 33 women, aged 18-45 years). The results presented suggest that the swept frequency bioimpedance technique estimates total body water, (SEE = 5.2%), and extracellular water, (SEE = 10%), only slightly better in normal, healthy subjects than a method based on single frequency bioimpedance or anthropometric estimates based on weight, height and gender. This study has undertaken the most extensive analysis to date of relationships between TBW (and ECW) and individual impedances obtained at different frequencies ( > 400 frequencies), and has shown marginal advantages of using one frequency over another, even if values predicted from theoretical bioimpedance models are used in the estimations. However in situations where there are disturbances of fluid distribution, values predicted from the Cole-Cole analysis of swept frequency bioimpedance measurements could prove to be more useful.

  18. Validation of bioelectrical impedance analysis to hydrostatic weighing in male body builders.

    PubMed

    Volpe, Stella Lucia; Melanson, Edward L; Kline, Gregory

    2010-03-01

    The purpose of this study was to compare bioelectrical impedance analysis (BIA) to hydrostatic weighing (HW) in male weight lifters and body builders. Twenty-two male body builders and weight lifters, 23 +/- 3 years of age (mean +/- SD), were studied to determine the efficacy of BIA to HW in this population. Subjects were measured on two separate occasions, 6 weeks apart, for test-retest reliability purposes. Participants recorded 3-day dietary intakes and average work-out times and regimens between the two testing periods. Subjects were, on average, 75 +/- 8 kg of body weight and 175 +/- 7 cm tall. Validation results were as follows: constant error for HW-BIA = 0.128 +/- 3.7%, r for HW versus BIA = -0.294. Standard error of the estimate for BIA = 2.32% and the total error for BIA = 3.6%. Percent body fat was 7.8 +/- 1% from BIA and 8.5 +/- 2% from HW (P > 0.05). Subjects consumed 3,217 +/- 1,027 kcals; 1,848 +/- 768 kcals from carbohydrates; 604 +/- 300 kcals from protein; and 783 +/- 369 kcals from fat. Although work-outs differed among one another, within subject training did not vary. These results suggest that measurement of percent body fat in male body builders and weight trainers is equally as accurate using BIA or HW.

  19. Impact of hemodialysis on dual X-ray absorptiometry, bioelectrical impedance measurements, and anthropometry.

    PubMed

    Abrahamsen, B; Hansen, T B; Høgsberg, I M; Pedersen, F B; Beck-Nielsen, H

    1996-01-01

    Dual X-ray absorptiometry (DXA) performs noninvasive assessment of bone and soft tissue with high precision. However, soft tissue algorithms assume that 73.2% of the lean body mass is water, a potential source of error in fluid retention. We evaluated DXA (model QDR-2000; Hologic Inc, Waltham, MA), bioelectrical impedance analysis (BIA), and simple anthropometry in 19 patients (9 women and 10 men, mean age 46 y) before and after hemodialysis, removing 0.9-4.3 L (x: 2.8L) of ultrafiltrate. The reduction in fat-free mass (FFM) measured by DXA was highly correlated with the ultrafiltrate, as determined by the reduction in gravimetric weight (r = 0.975, P < 0.0001; SEE: 233 g), whereas BIA was considerably less accurate in assessing FFM reductions (r = 0.66, P < 0.01; SEE: 757 g). Lumbar bone mineral density (BMD) was unaffected by dialysis, as were whole-body fat and BMD. Whole-body bone mineral content, however, was estimated to be 0.6% lower after dialysis. None of the simple anthropometric measurements correlated significantly with the reduction in FFM. In an unmodified clinical setting, DXA appears to be superior to other simple noninvasive methods for determining body composition, particularly when the emphasis is on repeated measurements.

  20. Comparison of hydrostatic weighing and bioelectric impedance measurements in determining body composition pre- and postdehydration.

    PubMed

    Pearman, P; Hunter, G; Hendricks, C; O'Sullivan, P

    1989-01-01

    This study investigated the effect of dehydration on measurements of body composition by hydrostatic weighing (HW) and bioelectric impedance analysis (BIA). Ten endurance-trained male athletes between the ages of 18 and 42 years performed an endurance training session consisting of running until body weight was reduced by approximately 3%. Body composition was determined prior to exercise and immediately after exercise by HW and BIA techniques. A high correlation existed between pre- and postdehydration for both HW and BIA. Validity coefficients between HW and BIA were moderate (predehydration 0.85 and postdehydration 0.82). In addition, BIA percent fat was 3.5% higher than HW percent fat. The BIA revealed a mean loss of 2.1% fat BIA and only 0.9% fat HW after approximately 45 minutes of exercise. BIA also showed an increase in percent body water (mean = 2.6%) in all 10 subjects after dehydration. There are indications that BIA, with its present equational configuration, is measuring something other than lean body weight. J Orthop Sports Phys Ther 1989;10(11):451-455.

  1. Validity of Bioelectrical Impedance Analysis to Estimation Fat-Free Mass in the Army Cadets.

    PubMed

    Langer, Raquel D; Borges, Juliano H; Pascoa, Mauro A; Cirolini, Vagner X; Guerra-Júnior, Gil; Gonçalves, Ezequiel M

    2016-03-11

    Bioelectrical Impedance Analysis (BIA) is a fast, practical, non-invasive, and frequently used method for fat-free mass (FFM) estimation. The aims of this study were to validate predictive equations of BIA to FFM estimation in Army cadets and to develop and validate a specific BIA equation for this population. A total of 396 males, Brazilian Army cadets, aged 17-24 years were included. The study used eight published predictive BIA equations, a specific equation in FFM estimation, and dual-energy X-ray absorptiometry (DXA) as a reference method. Student's t-test (for paired sample), linear regression analysis, and Bland-Altman method were used to test the validity of the BIA equations. Predictive BIA equations showed significant differences in FFM compared to DXA (p < 0.05) and large limits of agreement by Bland-Altman. Predictive BIA equations explained 68% to 88% of FFM variance. Specific BIA equations showed no significant differences in FFM, compared to DXA values. Published BIA predictive equations showed poor accuracy in this sample. The specific BIA equations, developed in this study, demonstrated validity for this sample, although should be used with caution in samples with a large range of FFM.

  2. The diagnostic accuracy of multi-frequency bioelectrical impedance analysis in diagnosing dehydration after stroke

    PubMed Central

    Kafri, Mohannad W.; Myint, Phyo Kyaw; Doherty, Danielle; Wilson, Alexander Hugh; Potter, John F.; Hooper, Lee

    2013-01-01

    Background Non-invasive methods for detecting water-loss dehydration following acute stroke would be clinically useful. We evaluated the diagnostic accuracy of multi-frequency bioelectrical impedance analysis (MF-BIA) against reference standards serum osmolality and osmolarity. Material/Methods Patients admitted to an acute stroke unit were recruited. Blood samples for electrolytes and osmolality were taken within 20 minutes of MF-BIA. Total body water (TBW%), intracellular (ICW%) and extracellular water (ECW%), as percentages of total body weight, were calculated by MF-BIA equipment and from impedance measures using published equations for older people. These were compared to hydration status (based on serum osmolality and calculated osmolarity). The most promising Receiver Operating Characteristics curves were plotted. Results 27 stroke patients were recruited (mean age 71.3, SD10.7). Only a TBW% cut-off at 46% was consistent with current dehydration (serum osmolality >300 mOsm/kg) and TBW% at 47% impending dehydration (calculated osmolarity ≥295–300 mOsm/L) with sensitivity and specificity both >60%. Even here diagnostic accuracy of MF-BIA was poor, a third of those with dehydration were wrongly classified as hydrated and a third classified as dehydrated were well hydrated. Secondary analyses assessing diagnostic accuracy of TBW% for men and women separately, and using TBW as a percentage of lean body mass showed some promise, but did not provide diagnostically accurate measures across the population. Conclusions MF-BIA appears ineffective at diagnosing water-loss dehydration after stroke and cannot be recommended as a test for dehydration, but separating assessment by sex, and using TBW as a percentage of lean body weight may warrant further investigation. PMID:23839255

  3. The diagnostic accuracy of multi-frequency bioelectrical impedance analysis in diagnosing dehydration after stroke.

    PubMed

    Kafri, Mohannad W; Myint, Phyo Kway; Doherty, Danielle; Wilson, Alexander Hugh; Potter, John F; Hooper, Lee

    2013-07-10

    Non-invasive methods for detecting water-loss dehydration following acute stroke would be clinically useful. We evaluated the diagnostic accuracy of multi-frequency bioelectrical impedance analysis (MF-BIA) against reference standards serum osmolality and osmolarity. Patients admitted to an acute stroke unit were recruited. Blood samples for electrolytes and osmolality were taken within 20 minutes of MF-BIA. Total body water (TBW%), intracellular (ICW%) and extracellular water (ECW%), as percentages of total body weight, were calculated by MF-BIA equipment and from impedance measures using published equations for older people. These were compared to hydration status (based on serum osmolality and calculated osmolarity). The most promising Receiver Operating Characteristics curves were plotted. 27 stroke patients were recruited (mean age 71.3, SD10.7). Only a TBW% cut-off at 46% was consistent with current dehydration (serum osmolality >300 mOsm/kg) and TBW% at 47% impending dehydration (calculated osmolarity ≥295-300 mOsm/L) with sensitivity and specificity both >60%. Even here diagnostic accuracy of MF-BIA was poor, a third of those with dehydration were wrongly classified as hydrated and a third classified as dehydrated were well hydrated. Secondary analyses assessing diagnostic accuracy of TBW% for men and women separately, and using TBW as a percentage of lean body mass showed some promise, but did not provide diagnostically accurate measures across the population. MF-BIA appears ineffective at diagnosing water-loss dehydration after stroke and cannot be recommended as a test for dehydration, but separating assessment by sex, and using TBW as a percentage of lean body weight may warrant further investigation.

  4. Validity of bioelectrical impedance measurement in predicting fat-free mass of Chinese children and adolescents.

    PubMed

    Wang, Lin; Hui, Stanley Sai-chuen; Wong, Stephen Heung-sang

    2014-11-15

    The current study aimed to examine the validity of various published bioelectrical impedance analysis (BIA) equations in estimating FFM among Chinese children and adolescents and to develop BIA equations for the estimation of fat-free mass (FFM) appropriate for Chinese children and adolescents. A total of 255 healthy Chinese children and adolescents aged 9 to 19 years old (127 males and 128 females) from Tianjin, China, participated in the BIA measurement at 50 kHz between the hand and the foot. The criterion measure of FFM was also employed using dual-energy X-ray absorptiometry (DEXA). FFM estimated from 24 published BIA equations was cross-validated against the criterion measure from DEXA. Multiple linear regression was conducted to examine alternative BIA equation for the studied population. FFM estimated from the 24 published BIA equations yielded high correlations with the directly measured FFM from DEXA. However, none of the 24 equations was statistically equivalent with the DEXA-measured FFM. Using multiple linear regression and cross-validation against DEXA measurement, an alternative prediction equation was determined as follows: FFM (kg)=1.613+0.742×height (cm)2/impedance (Ω)+0.151×body weight (kg); R2=0.95; SEE=2.45 kg; CV=6.5, 93.7% of the residuals of all the participants fell within the 95% limits of agreement. BIA was highly correlated with FFM in Chinese children and adolescents. When the new developed BIA equations are applied, BIA can provide a practical and valid measurement of body composition in Chinese children and adolescents.

  5. Validity of Bioelectrical Impedance Measurement in Predicting Fat-Free Mass of Chinese Children and Adolescents

    PubMed Central

    Wang, Lin; Hui, Stanley Sai-chuen; Wong, Stephen Heung-sang

    2014-01-01

    Background The current study aimed to examine the validity of various published bioelectrical impedance analysis (BIA) equations in estimating FFM among Chinese children and adolescents and to develop BIA equations for the estimation of fat-free mass (FFM) appropriate for Chinese children and adolescents. Material/Methods A total of 255 healthy Chinese children and adolescents aged 9 to 19 years old (127 males and 128 females) from Tianjin, China, participated in the BIA measurement at 50 kHz between the hand and the foot. The criterion measure of FFM was also employed using dual-energy X-ray absorptiometry (DEXA). FFM estimated from 24 published BIA equations was cross-validated against the criterion measure from DEXA. Multiple linear regression was conducted to examine alternative BIA equation for the studied population. Results FFM estimated from the 24 published BIA equations yielded high correlations with the directly measured FFM from DEXA. However, none of the 24 equations was statistically equivalent with the DEXA-measured FFM. Using multiple linear regression and cross-validation against DEXA measurement, an alternative prediction equation was determined as follows: FFM (kg)=1.613+0.742×height (cm)2/impedance (Ω)+0.151×body weight (kg); R2=0.95; SEE=2.45kg; CV=6.5, 93.7% of the residuals of all the participants fell within the 95% limits of agreement. Conclusions BIA was highly correlated with FFM in Chinese children and adolescents. When the new developed BIA equations are applied, BIA can provide a practical and valid measurement of body composition in Chinese children and adolescents. PMID:25398209

  6. Electrical impedance tomography during major open upper abdominal surgery: a pilot-study

    PubMed Central

    2014-01-01

    Background Electrical impedance tomography (EIT) of the lungs facilitates visualization of ventilation distribution during mechanical ventilation. Its intraoperative use could provide the basis for individual optimization of ventilator settings, especially in patients at risk for ventilation-perfusion mismatch and impaired gas exchange, such as patients undergoing major open upper abdominal surgery. EIT throughout major open upper abdominal surgery could encounter difficulties in belt positioning and signal quality. Thus, we conducted a pilot-study and tested whether EIT is feasible in patients undergoing major open upper abdominal surgery. Methods Following institutional review board’s approval and written informed consent, we included patients scheduled for major open upper abdominal surgery of at least 3 hours duration. EIT measurements were conducted prior to intubation, at the time of skin incision, then hourly during surgery until shortly prior to extubation and after extubation. Number of successful intraoperative EIT measurements and reasons for failures were documented. From the valid measurements, a functional EIT image of changes in tidal impedance was generated for every time point. Regions of interest were defined as horizontal halves of the picture. Monitoring of ventilation distribution was assessed using the center of ventilation index, and also using the total and dorsal ventilated lung area. All parameter values prior to and post intubation as well as extubation were compared. A p < 0.05 was considered statistically significant. Results A total of 120 intraoperative EIT measurements during major abdominal surgery lasting 4-13 hours were planned in 14 patients. The electrode belt was attached between the 2nd and 4th intercostal space. Consecutive valid measurements could be acquired in 13 patients (93%). 111 intraoperative measurements could be retrieved as planned (93%). Main obstacle was the contact of skin electrodes. Despite the high belt

  7. Validation of bioelectrical impedance analysis in Ethiopian adults with HIV.

    PubMed

    Hegelund, Maria H; Wells, Jonathan C; Girma, Tsinuel; Faurholt-Jepsen, Daniel; Zerfu, Dilnesaw; Christensen, Dirk L; Friis, Henrik; Olsen, Mette F

    2017-01-01

    Bioelectrical impedance analysis (BIA) is an inexpensive, quick and non-invasive method to determine body composition. Equations used in BIA are typically derived in healthy individuals of European descent. BIA is specific to health status and ethnicity and may therefore provide inaccurate results in populations of different ethnic origin and health status. The aim of the present study was to test the validity of BIA in Ethiopian antiretroviral-naive HIV patients. BIA was validated against the 2 H dilution technique by comparing fat-free mass (FFM) measured by the two methods using paired t tests and Bland-Altman plots. BIA was based on single frequency (50 kHz) whole-body measurements. Data were obtained at three health facilities in Jimma Zone, Oromia Region, South-West Ethiopia. Data from 281 HIV-infected participants were available. Two-thirds were female and the mean age was 32·7 (sd 8·6) years. Also, 46 % were underweight with a BMI below 18·5 kg/m 2 . There were no differences in FFM between the methods. Overall, BIA slightly underestimated FFM by 0·1 kg (-0·1, 95 % CI -0·3, 0·2 kg). The Bland-Altman plot indicated acceptable agreement with an upper limit of agreement of 4·5 kg and a lower limit of agreement of -4·6 kg, but with a small correlation between the mean difference and the average FFM. BIA slightly overestimated FFM at low values compared with the 2 H dilution technique, while it slightly underestimated FFM at high values. In conclusion, BIA proved to be valid in this population and may therefore be useful for measuring body composition in routine practice in HIV-infected African individuals.

  8. Alterations in body fluid content can be detected by bioelectrical impedance analysis.

    PubMed

    Scheltinga, M R; Jacobs, D O; Kimbrough, T D; Wilmore, D W

    1991-05-01

    The electrical resistance across the whole body and its segments to the conduction of a weak alternating current was determined in human subjects under three different conditions: (1) during bed rest, (2) during infusion of 1 liter of saline, and (3) during donation of 1 unit of blood. During bed rest, extracellular and total body water were measured by dilution of bromide and heavy water, respectively. Electrical resistance obtained from electrodes placed on proximal portions of extremities ("proximal resistance") accounted for less than 50% of that determined by electrodes positioned on routinely used portions of a hand and foot ("whole body resistance"). Following saline infusion, resistance determined from the whole body and all its segments fell (P less than 0.001); the magnitude of the drop in both proximal and whole body resistance was inversely related to the volume of total body water (TBW) (r = -0.82, P less than 0.002, and r = -0.73, P less than 0.01, respectively). In contrast, blood donation was associated with significantly increased resistance at both measurement sites. TBW predicted from anthropometrics was inversely related to both proximal (r = -0.90, P less than 0.001) and whole body resistance (r = -0.75, P less than 0.001). Bioelectrical impedance analysis is a simple technique which may be useful in monitoring minimal alterations in TBW. Furthermore, altered fluid status may be predicted more accurately by changes in proximal resistance compared to changes in traditionally used whole body resistance.

  9. Bioelectrical impedance analysis of bovine milk fat

    NASA Astrophysics Data System (ADS)

    Veiga, E. A.; Bertemes-Filho, P.

    2012-12-01

    Three samples of 250ml at home temperature of 20°C were obtained from whole, low fat and fat free bovine UHT milk. They were analysed by measuring both impedance spectra and dc conductivity in order to establish the relationship between samples related to fat content. An impedance measuring system was developed, which is based on digital oscilloscope, a current source and a FPGA. Data was measured by the oscilloscope in the frequency 1 kHz to 100 kHz. It was showed that there is approximately 7.9% difference in the conductivity between whole and low fat milk whereas 15.9% between low fat and free fat one. The change of fatness in the milk can be significantly sensed by both impedance spectra measurements and dc conductivity. This result might be useful for detecting fat content of milk in a very simple way and also may help the development of sensors for measuring milk quality, as for example the detection of mastitis.

  10. Bioelectrical impedance among rural Bangladeshi Women during pregnancy and in the postpartum period.

    PubMed

    Shaikh, Saijuddin; Schulze, Kerry J; Ali, Hasmot; Labrique, Alain B; Shamim, Abu Ahmed; Rashid, Mahbubur; Mehra, Sucheta; Christian, Parul; West, Keith P

    2011-06-01

    Properties of bioelectrical impedance analysis (BIA) reflect body-composition and may serve as stand-alone indicators of maternal health. Despite these potential roles, BIA properties during pregnancy and lactation in rural South Asian women have not been described previously, although pregnancy and infant health outcomes are often compromised. This paper reports the BIA properties among a large sample of pregnant and postpartum women of rural Bangladesh, aged 12-46 years, participating in a substudy of a community-based, placebo-controlled trial of vitamin A or beta-carotene supplementation. Anthropometry and single frequency (50 kHz) BIA were assessed in 1,435 women during the first trimester (< or =12 weeks gestation), in 1237 women during the third trimester (32-36 weeks gestation), and in 1,141 women at 12-18 weeks postpartum. Resistance and reactance were recorded, and impedance and phase angle were calculated. Data were examined cross-sectionally to maximize sample-size at each timepoint, and the factors relating to BIA properties were explored. Women were typically young, primiparous and lacking formal education (22.2 +/- 6.3 years old, 42.2% primiparous, and 39.7% unschooled among the first trimester participants). Weight (kg), resistance (omega), and reactance (omega) were 42.1 +/- 5.7, 688 +/- 77, and 73 +/- 12 in the first trimester; 47.7 +/- 5.9, 646 +/- 77, and 64 +/- 12 in the third trimester; and 42.7 +/- 5.6, 699 +/- 79, and 72 +/- 12 postpartum respectively. Resistance declined with age and increased with body mass index. Resistance was higher than that observed in other, non-Asian pregnant populations, likely reflecting considerably smaller body-volume among Bangladeshi women. Resistance and reactance decreased in advanced stage of pregnancy as the rate of gain in weight increased, returning to the first trimester values by the three months postpartum. Normative distributions of BIA properties are presented for rural Bangladeshi women across a

  11. Development of bioelectrical impedance analysis-based equations for estimation of body composition in postpartum rural Bangladeshi women.

    PubMed

    Shaikh, Saijuddin; Schulze, Kerry J; Kurpad, Anura; Ali, Hasmot; Shamim, Abu Ahmed; Mehra, Sucheta; Wu, Lee S-F; Rashid, Mahbubar; Labrique, Alain B; Christian, Parul; West, Keith P

    2013-02-28

    Equations for predicting body composition from bioelectrical impedance analysis (BIA) parameters are age-, sex- and population-specific. Currently there are no equations applicable to women of reproductive age in rural South Asia. Hence, we developed equations for estimating total body water (TBW), fat-free mass (FFM) and fat mass in rural Bangladeshi women using BIA, with ²H₂O dilution as the criterion method. Women of reproductive age, participating in a community-based placebo-controlled trial of vitamin A or β-carotene supplementation, were enrolled at 19·7 (SD 9·3) weeks postpartum in a study to measure body composition by ²H₂O dilution and impedance at 50 kHz using multi-frequency BIA (n 147), and resistance at 50 kHz using single-frequency BIA (n 82). TBW (kg) by ²H2O dilution was used to derive prediction equations for body composition from BIA measures. The prediction equation was applied to resistance measures obtained at 13 weeks postpartum in a larger population of postpartum women (n 1020). TBW, FFM and fat were 22·6 (SD 2·7), 30·9 (SD 3·7) and 10·2 (SD 3·8) kg by ²H₂O dilution. Height²/impedance or height²/resistance and weight provided the best estimate of TBW, with adjusted R² 0·78 and 0·76, and with paired absolute differences in TBW of 0·02 (SD 1·33) and 0·00 (SD 1·28) kg, respectively, between BIA and ²H₂O. In the larger sample, values for TBW, FFM and fat were 23·8, 32·5 and 10·3 kg, respectively. BIA can be an important tool for assessing body composition in women of reproductive age in rural South Asia where poor maternal nutrition is common.

  12. Evaluation of multifrequency bioelectrical impedance analysis in assessing body composition of wrestlers.

    PubMed

    Utter, Alan C; Lambeth, Pamela G

    2010-02-01

    To evaluate the accuracy of multifrequency bioelectrical impedance analysis (MFBIA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state. Body composition was determined by MFBIA, HW, and three-site SK in 72 high school wrestlers (mean +/- SD; age = 15.3 +/- 1.4 yr, height = 1.71 +/- 0.08 m, body mass = 67.3 +/- 13.4 kg). Hydration state was quantified by evaluating urine specific gravity. There were no significant differences for estimated FFM between MFBIA (57.2 +/- 9.5 kg) and HW (57.0 +/- 10.1 kg) or SK (56.4 +/- 8.8 kg). The SEE for FFM with HW as the reference method were 2.73 kg for MFBIA and 2.66 kg for SK. Correlations were found for FFM between HW and MFBIA (r = 0.96, P < 0.001) and between HW and SK (r = 0.97, P < 0.001). A systematic bias was found for MFBIA because the difference between MFBIA and HW correlated with the FFM average of the two methods (r = -0.22, P < 0.001). A bias was also seen between SK and HW and correlated with the FFM average (r = -0.47, P < 0.001). This study demonstrates that MFBIA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. MFBIA is an attractive assessment tool, easy to use, and may be considered as an alternative field-based method of estimating the FFM of high school wrestlers.

  13. Prediction of fat-free body mass from bioelectrical impedance and anthropometry among 3-year-old children using DXA

    PubMed Central

    Ejlerskov, Katrine T.; Jensen, Signe M.; Christensen, Line B.; Ritz, Christian; Michaelsen, Kim F.; Mølgaard, Christian

    2014-01-01

    For 3-year-old children suitable methods to estimate body composition are sparse. We aimed to develop predictive equations for estimating fat-free mass (FFM) from bioelectrical impedance (BIA) and anthropometry using dual-energy X-ray absorptiometry (DXA) as reference method using data from 99 healthy 3-year-old Danish children. Predictive equations were derived from two multiple linear regression models, a comprehensive model (height2/resistance (RI), six anthropometric measurements) and a simple model (RI, height, weight). Their uncertainty was quantified by means of 10-fold cross-validation approach. Prediction error of FFM was 3.0% for both equations (root mean square error: 360 and 356 g, respectively). The derived equations produced BIA-based prediction of FFM and FM near DXA scan results. We suggest that the predictive equations can be applied in similar population samples aged 2–4 years. The derived equations may prove useful for studies linking body composition to early risk factors and early onset of obesity. PMID:24463487

  14. Prediction of fat-free body mass from bioelectrical impedance and anthropometry among 3-year-old children using DXA.

    PubMed

    Ejlerskov, Katrine T; Jensen, Signe M; Christensen, Line B; Ritz, Christian; Michaelsen, Kim F; Mølgaard, Christian

    2014-01-27

    For 3-year-old children suitable methods to estimate body composition are sparse. We aimed to develop predictive equations for estimating fat-free mass (FFM) from bioelectrical impedance (BIA) and anthropometry using dual-energy X-ray absorptiometry (DXA) as reference method using data from 99 healthy 3-year-old Danish children. Predictive equations were derived from two multiple linear regression models, a comprehensive model (height(2)/resistance (RI), six anthropometric measurements) and a simple model (RI, height, weight). Their uncertainty was quantified by means of 10-fold cross-validation approach. Prediction error of FFM was 3.0% for both equations (root mean square error: 360 and 356 g, respectively). The derived equations produced BIA-based prediction of FFM and FM near DXA scan results. We suggest that the predictive equations can be applied in similar population samples aged 2-4 years. The derived equations may prove useful for studies linking body composition to early risk factors and early onset of obesity.

  15. Nutrition Status Parameters and Hydration Status by Bioelectrical Impedance Vector Analysis Were Associated With Lung Function Impairment in Children and Adolescents With Cystic Fibrosis.

    PubMed

    Hauschild, Daniela Barbieri; Barbosa, Eliana; Moreira, Emilia Addison Machado; Ludwig Neto, Norberto; Platt, Vanessa Borges; Piacentini Filho, Eduardo; Wazlawik, Elisabeth; Moreno, Yara Maria Franco

    2016-06-01

    (1) To compare nutrition and hydration status between a group of children/adolescents with cystic fibrosis (CFG; n = 46; median age, 8.5 years) and a control group without cystic fibrosis (CG). (2) To examine the association of nutrition and hydration status with lung function in the CFG. A cross-sectional study. Nutrition screening, anthropometric parameters, and bioelectrical impedance analysis (BIA) were assessed. The z scores for body mass index for age, height for age, mid upper arm circumference, triceps and subscapular skinfold thickness, mid upper arm muscle area, resistance/height, and reactance/height were calculated. Bioelectrical impedance vector analysis was conducted. Forced expiratory volume in 1 second <80% was considered lung function impairment. An adjusted logistic regression was applied (P < .05). In the CFG, lung function impairment was observed in 51.1%. All anthropometric parameters were lower, and the mean z-resistance/height and z-reactance/height were higher in the CFG (P < .05) compared with the CG. In the CFG, 43% were severely/mildly dehydrated, while none were in the CG (P = .007). In the CFG, there was an association between high nutrition risk-via nutrition screening (odds ratio [OR], 22.28; P < .05), lower values of anthropometric parameters, higher z-resistance/height (OR, 2.23; P < .05) and z-reactance/height (OR, 1.81; P < .05), and dehydration (OR, 4.94; P < .05)-and lung function impairment. The CFG exhibited a compromised nutrition status assessed by anthropometric and BIA parameters. Nutrition screening, anthropometric and BIA parameters, and hydration status were associated with lung function. © 2016 American Society for Parenteral and Enteral Nutrition.

  16. Validation of a portable bioelectrical impedance analyzer for the assessment of body composition.

    PubMed

    Karelis, Antony D; Chamberland, Gabriel; Aubertin-Leheudre, Mylène; Duval, Christian

    2013-01-01

    One of the major challenges in field research has been the difficulty to adequately measure body composition, such as % body fat and fat-free mass (FFM). Therefore, the purpose of the present study was to investigate the convergent validity of the portable bioelectrical impedance body composition analyzer, the Inbody 230, with dual X-ray absorptiometry (DXA) (General Electric Lunar Prodigy). The study population consisted of 145 men and women (age, 44.6 ± 20 years; BMI, 24.5 ± 3.8 kg·m(-2)). We measured body composition (fat mass, % body fat, total FFM, trunk FFM, and appendicular FFM) using DXA and the Inbody 230. Results show strong significant correlations between both methods for fat mass, % body fat, total FFM, and trunk FFM (r = 0.94-0.99). Furthermore, we showed a modest significant correlation between both methods for appendicular FFM (r = 0.63). Finally, as shown by Bland-Altman analysis, no significant biases were observed between Inbody 230 and DXA for fat mass, % body fat, and total FFM. However, trunk and appendicular FFM were shown to have significant biases between the Inbody 230 and DXA. In conclusion, the present study indicated that the portable Inbody 230 may be an acceptable device to measure fat mass, % body fat, and total FFM (except for women) in healthy adults. In addition, there appears to be a systematic bias for the estimation of trunk and appendicular FFM with the Inbody 230 in men and women.

  17. Bioelectrical impedance analysis for diagnosing sarcopenia and cachexia: what are we really estimating?

    PubMed

    Gonzalez, Maria Cristina; Heymsfield, Steven B

    2017-04-01

    As reference methods are not available for identifying low skeletal muscle mass in clinical practice, the European Group on Sarcopenia in Older People the Asian Working Group for Sarcopenia and the International Consensus for Cancer Cachexia guidelines accept bioelectrical impedance analysis (BIA) as an option for sarcopenia and cachexia assessment. Using different BIA equations, several components that represent 'muscularity' can be assessed. Total skeletal muscle mass or appendicular skeletal muscle mass normalized in relation to height (skeletal muscle mass index or appendicular skeletal muscle index, respectively) is the most common term used in the consensus. These terms are similar, but they should not be used as synonymous. Both terms can be used to define sarcopenia, but adequate equations and cut-off values should be used according to the studied population. However, there is a disagreement between the sarcopenia definition assessed by using BIA from the European Group on Sarcopenia in Older People and Cachexia Consensus, and this can lead to an overestimation of sarcopenia and, consequently, cachexia. An effort should be made to standardize the terminology employed by the Societies to define low muscularity and sarcopenia by using BIA. Future validation studies may show the need for specific cut-off values for each population using this method. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  18. Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women.

    PubMed

    Nascimento, Matheus A; Silva, Danilo R P; Ribeiro, Alex S; Pina, Fábio L C; Gerage, Aline M; Gobbo, Luís A; Mayhew, Jerry L; Cyrino, Edilson S

    2018-05-23

    Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res XX(X): 000-000, 2018-The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p < 0.001), although all equations had high correlations with DXA (r = 0.78-0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM (F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.

  19. Study and classification of the abdominal adiposity throughout the application of the two-dimensional predictive equation Garaulet et al., in the clinical practice.

    PubMed

    Piernas Sánchez, C M; Morales Falo, E M; Zamora Navarro, S; Garaulet Aza, M

    2010-01-01

    The excess of visceral abdominal adipose tissue is one of the major concerns in obesity and its clinical treatment. To apply the two-dimensional predictive equation proposed by Garaulet et al. to determine the abdominal fat distribution and to compare the results with the body composition obtained by multi-frequency bioelectrical impedance analysis (M-BIA). We studied 230 women, who underwent anthropometry and M-BIA. The predictive equation was applied. Multivariate lineal and partial correlation analyses were performed with control for BMI and % body fat, using SPSS 15.0 with statistical significance P < 0.05. Overall, women were considered as having subcutaneous distribution of abdominal fat. Truncal fat, regional fat and muscular mass were negatively associated with VA/SA(predicted), while the visceral index obtained by M-BIA was positively correlated with VA/SA(predicted). The predictive equation may be useful in the clinical practice to obtain an accurate, costless and safe classification of abdominal obesity.

  20. Predicting body composition using foot-to-foot bioelectrical impedance analysis in healthy Asian individuals.

    PubMed

    Wu, Chun-Shien; Chen, Yu-Yawn; Chuang, Chih-Lin; Chiang, Li-Ming; Dwyer, Gregory B; Hsu, Ying-Lin; Huang, Ai-Chun; Lai, Chung-Liang; Hsieh, Kuen-Chang

    2015-05-19

    The objectives of this study were to develop a regression model for predicting fat-free mass (FFM) in a population of healthy Taiwanese individuals using standing foot-to-foot bioelectrical impedance analysis (BIA) and to test the model's performance in predicting FFM with different body fat percentages (BF%). We used dual-energy X-ray absorptiometry (DXA) to measure the FFM of 554 healthy Asian subjects (age, 16-75 y; body mass index, 15.8-43.1 kg/m(2)). We also evaluated the validity of the developed multivariate model using a double cross-validation technique and assessed the accuracy of the model in an all-subjects sample and subgroup samples with different body fat levels. Predictors in the all-subjects multivariate model included height(2)/impedance, weight, year, and sex (FFM = 13.055 + 0.204 weight + 0.394 height(2)/Impedance - 0.136 age + 8.125 sex (sex: Female = 0, Male = 1), r(2) = 0.92, standard error of the estimate = 3.17 kg). The correlation coefficients between predictive FFM by BIA (FFMBIA) and DXA-measured FFM (FFMDXA) in female subjects with a total-subjects BF%DXA of <20 %, 20 %-30 %, 30 %-40 % and >40 % were r = 0.87, 0.90, 0.91, 0.89, and 0.94, respectively, with bias ± 2SD of 0.0 ± 3.0 kg, -2.6 ± 1.7 kg, -1.5 ± 2.8 kg, 0.5 ± 2.7 kg, and 2.0 ± 2.9 kg, respectively. The correlation coefficients between FFMBIA and FFMDXA in male subjects with a total-subjects BF%DXA of <10 %, 10 %-20 %, 20 %-30 %, and >30 % were r = 0.89, 0.89, 0.90, 0.93, and 0.91, respectively, with bias ± 2SD of 0.0 ± 3.2 kg, -2.3 ± 2.5 kg, -0.5 ± 3.2 kg, 0.4 ± 3.1 kg, and 2.1 ± 3.2 kg, respectively. The standing foot-to-foot BIA method developed in this study can accurately predict FFM in healthy Asian individuals with different levels of body fat.

  1. The novel application of artificial neural network on bioelectrical impedance analysis to assess the body composition in elderly

    PubMed Central

    2013-01-01

    Background This study aims to improve accuracy of Bioelectrical Impedance Analysis (BIA) prediction equations for estimating fat free mass (FFM) of the elderly by using non-linear Back Propagation Artificial Neural Network (BP-ANN) model and to compare the predictive accuracy with the linear regression model by using energy dual X-ray absorptiometry (DXA) as reference method. Methods A total of 88 Taiwanese elderly adults were recruited in this study as subjects. Linear regression equations and BP-ANN prediction equation were developed using impedances and other anthropometrics for predicting the reference FFM measured by DXA (FFMDXA) in 36 male and 26 female Taiwanese elderly adults. The FFM estimated by BIA prediction equations using traditional linear regression model (FFMLR) and BP-ANN model (FFMANN) were compared to the FFMDXA. The measuring results of an additional 26 elderly adults were used to validate than accuracy of the predictive models. Results The results showed the significant predictors were impedance, gender, age, height and weight in developed FFMLR linear model (LR) for predicting FFM (coefficient of determination, r2 = 0.940; standard error of estimate (SEE) = 2.729 kg; root mean square error (RMSE) = 2.571kg, P < 0.001). The above predictors were set as the variables of the input layer by using five neurons in the BP-ANN model (r2 = 0.987 with a SD = 1.192 kg and relatively lower RMSE = 1.183 kg), which had greater (improved) accuracy for estimating FFM when compared with linear model. The results showed a better agreement existed between FFMANN and FFMDXA than that between FFMLR and FFMDXA. Conclusion When compared the performance of developed prediction equations for estimating reference FFMDXA, the linear model has lower r2 with a larger SD in predictive results than that of BP-ANN model, which indicated ANN model is more suitable for estimating FFM. PMID:23388042

  2. Intra-abdominal fat accumulation is a hypertension risk factor in young adulthood

    PubMed Central

    Takeoka, Atsushi; Tayama, Jun; Yamasaki, Hironori; Kobayashi, Masakazu; Ogawa, Sayaka; Saigo, Tatsuo; Kawano, Hiroaki; Abiru, Norio; Hayashida, Masaki; Maeda, Takahiro; Shirabe, Susumu

    2016-01-01

    Abstract Accumulation of intra-abdominal fat is related to hypertension. Despite this, a relationship between hypertension and intra-abdominal fat in young adulthood is not clear. In this study, we verify whether intra-abdominal fat accumulation increases a hypertension risk in young adult subjects. In a cross-sectional study, intra-abdominal fat area was measured using a dual bioelectrical impedance analysis instrument in 697 university students (20.3 ± 0.7 years, 425 men). Blood pressure and anthropometric factors were measured. Lifestyle variables including smoking, drinking, physical activity, and eating behavior were assessed with questionnaire. High blood pressure risk (systolic blood pressure ≥130 mm Hg and/or diastolic blood pressure ≥85 mm Hg) with increasing intra-abdominal fat area was evaluated. Participants were divided into 5 groups according to their intra-abdominal fat area (≤24.9, 25–49.9, 50–74.9, 75–99.9, and ≥100 cm2). As compared with the values of the smallest intra-abdominal fat area group, the crude and lifestyle-adjusted odds ratios (ORs) were elevated in larger intra-abdominal fat area groups [OR 1.31, 95% confidence interval (CI) 0.66–2.80; OR 3.38, 95% CI 1.60–7.57; OR 7.71, 95% CI 2.75–22.22; OR 18.74, 95% CI 3.93–105.64, respectively). The risk increase was observed only in men. Intra-abdominal fat accumulation is related to high blood pressure in men around 20 years of age. These results indicate the importance of evaluation and reduction of intra-abdominal fat to prevent hypertension. PMID:27828861

  3. Ratio of muscle mass to fat mass assessed by bioelectrical impedance analysis is significantly correlated with liver fat accumulation in patients with type 2 diabetes mellitus.

    PubMed

    Kurinami, Noboru; Sugiyama, Seigo; Morita, Ayami; Yoshida, Akira; Hieshima, Kunio; Miyamoto, Fumio; Kajiwara, Keizo; Jinnouch, Katsunori; Jinnouchi, Tomio; Jinnouchi, Hideaki

    2018-05-01

    Obesity and ectopic fat accumulation are important conditions of type 2 diabetes mellitus (T2DM). Our aim was to determine whether bioelectrical impedance body composition analysis combined with blood test results could estimate liver ectopic fat accumulation in patients with treatment-naïve T2DM. Subjects were 119 untreated T2DM patients. Computed tomography scans were performed to calculate the liver to spleen attenuation ratio (L/S ratio) as a measure of liver fat accumulation, with excess liver fat accumulation defined as an L/S ratio <1.0. Elementary body composition was measured by bioelectrical impedance analysis using InBody770. The Nagelkerke R 2 test showed that the muscle mass/fat mass ratio (muscle/fat ratio) was the most suitable variable among anthropometric factors and body component indexes for estimating liver fat accumulation. The muscle/fat ratio was significantly correlated with the L/S ratio (ρ = 0.4386, P < 0.0001). Multivariable logistic regression analysis showed that the muscle/fat ratio (odds ratio 0.40, 95% confidence interval 0.22-0.73, P < 0.01) and alanine aminotransferase (odds ratio 1.06, 95% confidence interval 1.02-1.10, P < 0.01) were independently and significantly associated with liver fat accumulation. In receiver operating characteristic curve analysis, the cutoff value of the muscle/fat ratio for excess liver fat accumulation was 2.34. In patients with treatment-naïve T2DM, the muscle/fat ratio and ALT are useful for estimating the presence of excess liver fat accumulation in daily clinical practice. Copyright © 2018. Published by Elsevier B.V.

  4. Association of phase angle on bioelectrical impedance analysis and dialysis frequency with survival of chronic hemodialysis patients

    NASA Astrophysics Data System (ADS)

    Muzasti, R. A.; Lubis, H. R.

    2018-03-01

    Phase angle, a parameter by Bioelectrical Impedance Analysis, can detect body composition changes, so it can be used as a prognostic indicator in some chronic conditions. This study was for determining the relationship between PhA and hemodiálisis frequency with the survival of chronic hemodiálisis patients. This longitudinal retrospective study involved 173 chronic hemodiálisis patients at Rasyida Renal Hospital. The Kaplan-Meier method is used to determine the survival. Cox proportional hazard analysis is used to determine which variables significantly increase mortality. During the study period, 89 patients underwent hemodiálysis 3x a week (4 hours/session), and 84 patients underwent HD 2x a week (5 hours/session). Demographic and clinical characteristics in both groups were similar. There was no difference in PhA value in groups of 3x a week and group 2x a week (4.02 ± 1.13 vs 4.25 ± 1.12). Patients with twice a week hemodiálisis had a shorter survival than the 3x week group (35.14 ± 2.76 vs 38.62 ± 3.03) although it was not statistically significant (p = 0.126).

  5. Could bioelectric impedance spectroscopy (BIS) measured appendicular intracellular water serve as a lean mass measurement in sarcopenia definitions? A pilot study.

    PubMed

    Siglinsky, E; Buehring, B; Krueger, D; Binkley, N; Yamada, Y

    2018-03-25

    DXA lean mass measurement for sarcopenia diagnosis is not always possible. Bioelectric impedance spectroscopy (BIS), a portable technology, is a potential alternative to DXA-measured lean mass. This pilot study explores the possibility and proposes an arbitrarily chosen potential cut-point for appendicular intracellular water corrected by height (aICW/ht 2 ). Sarcopenia definitions often include DXA lean mass measurement. However, DXA is not always available. We explored the potential of a less-expensive mobile method, bioelectric impedance spectroscopy (BIS), to assess lean mass for sarcopenia determination. We hypothesized that BIS-measured appendicular intracellular water (aICW/ht 2 ) would correlate with DXA-measured appendicular lean mass (ALM)/ht 2 and with functional parameters. If so, establishing an aICW/ht 2 cut-point in sarcopenia definitions may be feasible. Sixty-one community-dwelling women, mean age 79.9, had BIS and DXA lean mass, grip strength, gait speed, and jumping mechanography assessments. BIS aICW was calculated using limb length and intracellular water resistance. aICW/ht 2 was compared to DXA-measured ALM/ht 2 by linear regression. The European Working Group ALM/ht 2 and an exploratory aICW/ht 2 cut-point were utilized. In this cohort, ALM/ht 2 and aICW/ht 2 were moderately correlated, R 2  = 0.55, p < 0.0001. Lean mass was low in 7 and normal in 44 by BIS and DXA. Those with low aICW/ht 2 had lower grip strength (p = 0.04) and jump power (p = 0.0002) than those with normal aICW/ht 2 and ALM/ht 2 . Subjects with low ALM/ht 2 had lower jump power (p = 0.0006) but were not different in gait speed or grip strength. BIS aICW is correlated with DXA-measured ALM directly, and when height adjusted. An aICW/ht 2 cut-point of 6.5 L/m 2 identified 70% of women with low ALM/ht 2 . Women with low lean mass by DXA and BIS had poorer function measured by jump power. These pilot data support further evaluation of BIS measurement

  6. Total and Segmental Body Composition Examination in Collegiate Football Players Using Multifrequency Bioelectrical Impedance Analysis and Dual X-ray Absorptiometry.

    PubMed

    Raymond, Christiana J; Dengel, Donald R; Bosch, Tyler A

    2018-03-01

    Raymond, CJ, Dengel, DR, and Bosch, TA. Total and segmental body composition examination in collegiate football players using multifrequency bioelectrical impedance analysis and dual X-ray absorptiometry. J Strength Cond Res 32(3): 772-782, 2018-The current study examined the influence of player position on the agreement between multifrequency bioelectrical impedance analysis (MfBIA) and dual X-ray absorptiometry (DXA) when assessing total and segmental percent body fat (BF%), fat mass (FM), and fat-free mass (FFM) in National Collegiate Athletic Association Division I collegiate football athletes. Forty-four male collegiate athletes (age = 19 ± 1 year; height = 1.9 ± 1.0 m; and body mass = 106.4 ± 18.8 kg) participated. Player positions included: offensive linemen (OL; n = 7), tight ends (TE; n = 4), wide receivers (WR; n = 9), defensive linemen (DL; n = 6), defensive backs (DB; n = 8), linebackers (LB; n = 6), and running backs (RB; n = 4). Total and segmental body composition measured using MfBIA were compared with values obtained using DXA. Compared with DXA, MfBIA underestimated BF% (3.0 ± 3.8%), total FM (2.5 ± 4.3 kg), arm FM (0.4 ± 0.8 kg), arm FFM (1.4 ± 0.9 kg), leg FM (2.8 ± 2.0 kg), and leg FFM (5.4 ± 2.4 kg) (all p < 0.001; arm FM p = 0.002) and overestimated total FFM (-2.4 ± 4.5 kg) (p < 0.001). Limits of agreement (LOAs) were: ±7.39% (BF%), ±8.50 kg (total FM), ±1.50 kg (arm FM), ±1.83 kg (arm FFM), ±3.83 kg (leg FM), ±4.62 kg (leg FFM), and ±8.83 kg (total FFM). No significant differences were observed between devices for trunk FM (-0.3 ± 3.0 kg; p = 0.565) and trunk FFM (0.4 ± 2.4 kg; p = 0.278), with LOAs of ±5.92 and ±4.69 kg, respectively. Player position significantly affected all between-device mean body composition measurement differences (adjusted p ≤ 0.05), with OL demonstrating the greatest effect on each variable. Therefore, MfBIA does not seem accurate in examining between-player body composition in college

  7. Computational method for estimating boundary of abdominal subcutaneous fat for absolute electrical impedance tomography.

    PubMed

    Yamaguchi, Tohru F; Okamoto, Yoshiwo

    2018-01-01

    Abdominal fat accumulation is considered an essential indicator of human health. Electrical impedance tomography has considerable potential for abdominal fat imaging because of the low specific conductivity of human body fat. In this paper, we propose a robust reconstruction method for high-fidelity conductivity imaging by abstraction of the abdominal cross section using a relatively small number of parameters. Toward this end, we assume homogeneous conductivity in the abdominal subcutaneous fat area and characterize its geometrical shape by parameters defined as the ratio of the distance from the center to boundary of subcutaneous fat to the distance from the center to outer boundary in 64 equiangular directions. To estimate the shape parameters, the sensitivity of the noninvasively measured voltages with respect to the shape parameters is formulated for numerical optimization. Numerical simulations are conducted to demonstrate the validity of the proposed method. A 3-dimensional finite element method is used to construct a computer model of the human abdomen. The inverse problems of shape parameters and conductivities are solved concurrently by iterative forward and inverse calculations. As a result, conductivity images are reconstructed with a small systemic error of less than 1% for the estimation of the subcutaneous fat area. A novel method is devised for estimating the boundary of the abdominal subcutaneous fat. The fidelity of the overall reconstructed image to the reference image is significantly improved. The results demonstrate the possibility of realization of an abdominal fat scanner as a low-cost, radiation-free medical device. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Cross-validation of bioelectrical impedance analysis of body composition in children and adolescents.

    PubMed

    Wu, Y T; Nielsen, D H; Cassady, S L; Cook, J S; Janz, K F; Hansen, J R

    1993-05-01

    The reliability and validity of measurements obtained with two bioelectrical impedance analyzers (BIAs), an RJL Systems model BIA-103 and a Berkeley Medical Research BMR-2000, were investigated using the manufacturers' prediction equations for the assessment of fat-free mass (FFM) (in kilograms) in children and adolescents. Forty-seven healthy children and adolescents (23 male, 24 female), ranging in age from 8 to 20 years (mean = 12.1, SD = 2.3), participated. In the context of a repeated-measures design, the data were analyzed according to gender and maturation (Tanner staging). Hydrostatic weighing (HYDRO) and Lohman's Siri age-adjusted body density prediction equation served as the criteria for validating the BIA-obtained measurements. High intraclass correlation coefficients (ICC > or = .987) demonstrated good test-retest (between-week) measurement reliability for HYDRO and both BIA methods. Between-method (HYDRO versus BIA) correlation coefficients were high for both boys and girls (r > or = .97). The standard errors of estimate (SEEs) for FFM were slightly larger for boys than for girls and were consistently smaller for the RJL system than for the BMR system (RJL SEE = 1.8 kg for boys, 1.3 kg for girls; BMR SEE = 2.4 kg for boys, 1.9 kg for girls). The coefficients of determination were high for both BIA methods (r2 > or = .929). Total prediction errors (TEs) for FFM showed similar between-method trends (RJL TE = 2.1 kg for boys, 1.5 kg for girls; BMR TE = 4.4 kg for boys, 1.9 kg for girls). This study demonstrated that the RJL BIA with the manufacturer's prediction equations can be used to reliably and accurately assess FFM in 8- to 20-year-old children and adolescents. The prediction of FFM by the BMR system was acceptable for girls, but significant overprediction of FFM for boys was noted.

  9. Assessment of hydration status using bioelectrical impedance vector analysis in critical patients with acute kidney injury.

    PubMed

    Hise, Ana Cláudia da Rosa; Gonzalez, Maria Cristina

    2018-04-01

    The state of hyperhydration in critically ill patients with acute kidney injury (AKI) is associated with increased mortality. Bioelectrical impedance vector analysis (BIVA) appears to be a viable method to access the fluid status of critical patients but has never been evaluated in critical patients with AKI. The objective of this study is to evaluate the hydration status measured using BIVA in critical patients under intensive care at the time of AKI diagnosis and to correlate this measurement with mortality. We assessed the fluid status measured using BIVA in 224 critical patients at the time of AKI diagnosis and correlated it with mortality. To interpret the results, BIVA Software 2002 was used to plot the data from the patients studied on the 95% confidence ellipses of the RX c plane for comparisons between groups (non-survivors, survivors). Variables such as mechanical ventilation, vasoactive drug, and sepsis, among others, were collected. The impedance vector analysis conducted using BIVA Software 2002 indicated changes in the body compositions of patients according to the 95% confidence ellipse between the vectors R/H and X c /H of the group of survivors and the group of deceased patients. Hotelling's test (T 2  = 21.2) and the F test (F = 10.6) revealed significant differences (p < 0.001) between the two groups. These results demonstrate that patients who died presented with a greater hydration volume at the time of AKI diagnosis compared with those who survived. In addition to the hydration status measured using BIVA, the following were also correlated with death: diagnosis at hospitalization, APACHE II score, length of hospital stay, RIFLE score, maximum organ failure, sepsis type, hemoglobin, and AF. The fluid status assessment measured using BIVA significantly demonstrated the difference in hydration between survivors and non-survivors among critically ill patients with AKI. Copyright © 2017 Elsevier Ltd and European Society for Clinical

  10. Body composition by bioelectrical-impedance analysis compared with deuterium dilution and skinfold anthropometry in patients with chronic obstructive pulmonary disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schols, A.M.; Wouters, E.F.; Soeters, P.B.

    1991-02-01

    Body composition is an important measure of nutritional status in patients with chronic obstructive pulmonary disease (COPD). We generated a regression model for bioelectrical impedance (BI) by using deuterium dilution (2H2O) as a reference method in 32 COPD patients, aged 63 +/- 9 y (mean +/- SD), in stable pulmonary and cardiac condition. Height squared divided by resistance (Ht2/Res) correlated well with total body water (TBW) as measured by 2H2O (r = 0.93, P less than 0.001, SEE = 1.9 L). The best-fitting regression equation to predict TBW comprised Ht2/Res and body weight (r2 = 0.89, SEE = 1.8 L,more » P less than 0.001). BI-predicted TBW was used to estimate BI-fat-free mass (FFM) that was compared with skinfold-thickness-based FFM predictions (Anthr-FFM). Relative to BI-FFM a significant overestimation of 4.4 +/- 0.8 kg was found by Anthr-FFM. Our results suggest that BI is a useful measure of body composition in patients with severe COPD.« less

  11. Comparison of Multifrequency Bioelectrical Impedance vs. Dual-Energy X-ray Absorptiometry for Assessing Body Composition Changes After Participation in a 10-Week Resistance Training Program.

    PubMed

    Schoenfeld, Brad J; Nickerson, Brett S; Wilborn, Colin D; Urbina, Stacie L; Hayward, Sara B; Krieger, James; Aragon, Alan A; Tinsley, Grant M

    2018-06-20

    Schoenfeld, BJ, Nickerson, BS, Wilborn, CD, Urbina, SL, Hayward, SB, Krieger, J, Aragon, AA, and Tinsley, G. Comparison of multifrequency bioelectrical impedance vs. dual-energy x-ray absorptiometry for assessing body composition changes after participation in a 10-week resistance training program. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to assess the ability of multifrequency bioelectrical impedance analysis (MF-BIA) to determine alterations in total and segmental body composition across a 10-week resistance training (RT) program in comparison with the criterion reference dual-energy X-ray absorptiometry (DXA). Twenty-one young male volunteers (mean ± SD; age = 22.9 ± 3.0 years; height = 175.5 ± 5.9 cm; body mass = 82.9 ± 13.6 kg; body mass index = 26.9 ± 3.6) performed an RT program that included exercises for all major muscle groups. Body composition was assessed using both methods before and after the intervention; change scores were determined by subtracting pre-test values from post-test values for percent body fat ([INCREMENT]%BF), fat mass ([INCREMENT]FM), and fat-free mass ([INCREMENT]FFM). Mean changes were not significantly different when comparing MF-BIA with DXA for [INCREMENT]%BF (-1.05 vs. -1.28%), [INCREMENT]FM (-1.13 vs. -1.19 kg), and FFM (0.10 vs. 0.37 kg, respectively). Both methods showed strong agreement for [INCREMENT]%BF (r = 0.75; standard error of the estimate [SEE] = 1.15%), [INCREMENT]FM (r = 0.84; SEE 1.0 kg), and [INCREMENT]FFM (r = 0.71; SEE of 1.5 kg). The 2 methods were poor predictors of each other in regards to changes in segmental measurements. Our data indicate that MF-BIA is an acceptable alternative for tracking changes in FM and FFM during a combined diet and exercise program in young, athletic men, but segmental lean mass measurements must be interpreted with circumspection.

  12. Intra-abdominal fat accumulation is a hypertension risk factor in young adulthood: A cross-sectional study.

    PubMed

    Takeoka, Atsushi; Tayama, Jun; Yamasaki, Hironori; Kobayashi, Masakazu; Ogawa, Sayaka; Saigo, Tatsuo; Kawano, Hiroaki; Abiru, Norio; Hayashida, Masaki; Maeda, Takahiro; Shirabe, Susumu

    2016-11-01

    Accumulation of intra-abdominal fat is related to hypertension. Despite this, a relationship between hypertension and intra-abdominal fat in young adulthood is not clear. In this study, we verify whether intra-abdominal fat accumulation increases a hypertension risk in young adult subjects.In a cross-sectional study, intra-abdominal fat area was measured using a dual bioelectrical impedance analysis instrument in 697 university students (20.3 ± 0.7 years, 425 men). Blood pressure and anthropometric factors were measured. Lifestyle variables including smoking, drinking, physical activity, and eating behavior were assessed with questionnaire. High blood pressure risk (systolic blood pressure ≥130 mm Hg and/or diastolic blood pressure ≥85 mm Hg) with increasing intra-abdominal fat area was evaluated.Participants were divided into 5 groups according to their intra-abdominal fat area (≤24.9, 25-49.9, 50-74.9, 75-99.9, and ≥100 cm). As compared with the values of the smallest intra-abdominal fat area group, the crude and lifestyle-adjusted odds ratios (ORs) were elevated in larger intra-abdominal fat area groups [OR 1.31, 95% confidence interval (CI) 0.66-2.80; OR 3.38, 95% CI 1.60-7.57; OR 7.71, 95% CI 2.75-22.22; OR 18.74, 95% CI 3.93-105.64, respectively). The risk increase was observed only in men.Intra-abdominal fat accumulation is related to high blood pressure in men around 20 years of age. These results indicate the importance of evaluation and reduction of intra-abdominal fat to prevent hypertension.

  13. Comparison of two bioelectrical impedance analysis instruments for determining body composition in adolescent girls

    PubMed Central

    Nichols, J.; Going, S.; Loftin, M.; Stewart, D.; Nowicki, E.; Pickrel, J.

    2007-01-01

    The purpose of this study was to compare fat-free mass (FFM) and percent body fat determined by two bio-electrical impedance analysis (BIA) instruments against criterion estimates determined by dual-energy x-ray absorptiometry (DXA) in a multi-racial/ethnic sample of adolescent girls. BIA was assessed in 151 girls (n=51 African-American; n=45 Hispanic; n=55 Caucasian; age 12.2 ± 1.2 yr) using the RJL Quantum II and the American Weights and Measures Body-Comp Scale (BCS). Percent body fat determined by BIA was significantly related to that determined by DXA (R2=0.87, SEE=2.8% for RJL vs DXA, P<0.0001; R2=0.71, SEE=4.4% for BCS vs DXA, P<0.0001). The agreement between DXA and BIA for FFM was also significant (R2=0.91, SEE=0.03 kg for RJL, P <0.0001; R2=0.79, SEE=0.04 kg for BCS, P <0.0001). The BCS overestimated FFM by 2.7 kg (P<0.0001) and underestimated percent body fat by over 4% (P<0.001). There were no differences in percent body fat between DXA and the RJL, and although the RJL significantly overestimated FFM, the absolute difference was <1 kg. Within each ethnic group, the RJL instrument more closely estimated FFM and percent body fat than did the BCS. Although both BIA instruments compared favorably with DXA, the RJL had better stability and accuracy than the BCS, for both the total sample and for the three ethnic groups. Considering its relatively low cost and minimal time required for technical training, BIA is a useful and appropriate technique for assessing body composition in adolescent girls. PMID:17607326

  14. Body fluid volume and nutritional status in hemodialysis: vector bioelectric impedance analysis.

    PubMed

    Espinosa Cuevas, M A; Navarrete Rodriguez, G; Villeda Martinez, M E; Atilano Carsi, X; Miranda Alatriste, P; Tostado Gutiérrez, T; Correa-Rotter, R

    2010-04-01

    Protein-energy malnutrition and hypervolemia are major causes of morbidity and mortality in patients on chronic hemodialysis (CHD). The methods used to evaluate nutritional status and volume status remain controversial. Vector bioelectric impedance analysis (vector- BIA) has recently been developed to assess both nutritional status and tissue hydration. The purpose of the study was to assess the nutritional status and volume status of patients on CHD with conventional nutritional assessment methods and with vector-BIA and then to compare the resulting findings. 76 Mexican patients on CHD were studied. Nutritional status and body composition were assessed with anthropometry, biochemical variables, and the modified Bilbrey nutritional index (mBNI), the results were compared with both conventional BIA and vector-BIA. The BNI was used to determine the number of patients with normal nutritional status (n = 27, 35.5%), and mild (n = 31, 40.8%), moderate (n = 10, 13.2%) and severe malnutrition (n = 8, 10.5%). Patients displayed shorter vectors with smaller phase angles or with an overhydration vectorial pattern before the initiation of their hemodialysis session. There was general improvement to normal hydration status post-dialysis (p < 0.05); however, 28% remained overhydrated as assessed by vector-BIA. The vector-BIA results showed that worse malnutrition status was associated with greater volume overload (p < 0.05). Diabetes mellitus (DM) was associated with shorter vectors with smaller phase angles (a vectorial pattern of overhydration and cachexia) (p < 0.05). Patients with lower serum creatinine presented with shorter vectors and smaller phase angles (vectorial patterns of malnutrition and/or overhydration) (p < 0.05). In women, lower serum albumin (< 3.4 g/dl) correlated with greater overhydration and malnutrition (p < 0.05). In this population, the vector-BIA showed that 28% of the population remained overhydrated after their hemodialysis session. Diabetics and

  15. Multi-frequency bioelectrical impedance: a comparison between the Cole-Cole modelling and Hanai equations with the classical impedance index approach.

    PubMed

    Deurenberg, P; Andreoli, A; de Lorenzo, A

    1996-01-01

    Total body water and extracellular water were measured by deuterium oxide and bromide dilution respectively in 23 healthy males and 25 healthy females. In addition, total body impedance was measured at 17 frequencies, ranging from 1 kHz to 1350 kHz. Modelling programs were used to extrapolate impedance values to frequency zero (extracellular resistance) and frequency infinity (total body water resistance). Impedance indexes (height2/Zf) were computed at all 17 frequencies. The estimation errors of extracellular resistance and total body water resistance were 1% and 3%, respectively. Impedance and impedance index at low frequency were correlated with extracellular water, independent of the amount of total body water. Total body water showed the greatest correlation with impedance and impedance index at high frequencies. Extrapolated impedance values did not show a higher correlation compared to measured values. Prediction formulas from the literature applied to fixed frequencies showed the best mean and individual predictions for both extracellular water and total body water. It is concluded that, at least in healthy individuals with normal body water distribution, modelling impedance data has no advantage over impedance values measured at fixed frequencies, probably due to estimation errors in the modelled data.

  16. Prevalence of rheumatoid cachexia assessed by bioelectrical impedance vector analysis and its relation with physical function.

    PubMed

    Santillán-Díaz, Cira; Ramírez-Sánchez, Noemi; Espinosa-Morales, Rolando; Orea-Tejeda, Arturo; Llorente, Luis; Rodríguez-Guevara, Gerardo; Castillo-Martínez, Lilia

    2018-03-01

    Rheumatoid arthritis (RA) patients frequently have changes in their body composition, with a decrease in muscle mass and an increase in fat mass, a syndrome that is termed rheumatoid cachexia (RC). The prevalence of this nutritional alteration is not well known; there is as yet no consensus, seeing as it depends on the methods, techniques, and cutoff points that are used for its diagnosis. The main aim of this study was to identify RC through assessment by bioelectrical impedance vector analysis (BIVA) and its association with metabolic causes, physical function, and the main disease status, among others. The prevalence of RC was identified in those subjects who fell outside the right lower quadrant of the reference curve of RXc graph of BIVA. Clinical, anthropometric, biochemical and physical activity, emotional status, and diet markers were also evaluated. Ninety-four patients were included (92.55% women). The prevalence of RC assessed by BIVA was 21.28%. BIVA-cachexia patients had a lesser value of handgrip strength vs. patients without BIVA-cachexia 10.2 kg (7.2-13.4) vs. 14.7 kg (9.6-19), p = 0.0062. Disability and folic acid with methotrexate consumption are related to BIVA-cachexia ((OR 4.69, 95% CI 1.33, 16.54, p = 0.016) and (OR 0.19, 95%CI 0.058, 0.651, p = 0.008), respectively). BIVA could represent a valuable tool to assess presence of RC. It is important that RA patients have physical therapy to improve their nutritional status.

  17. Validation of bioelectrical impedance analysis (BIA) for estimation of body composition in Black, White and Hispanic adolescent girls

    PubMed Central

    Going, S.; Nichols, J.; Loftin, M.; Stewart, D.; Lohman, T.; Tuuri, G.; Ring, K.; Pickrel, J.; Blew, R.; J.Stevens

    2007-01-01

    Aim Equations for estimating % fat mass (%BF) and fat-free mass (FFM) from bioelectrical impedance analysis (BIA) that work in adolescent girls from different racial/ethnic backgrounds are not available. We investigated whether race/ethnicity influences estimation of body composition in adolescent girls. Principal procedures Prediction equations were developed for estimating FFM and %BF from BIA in 166 girls, 10–15 years old, consisting of 51 Black (B), 45 non-Black Hispanic (H), 55 non-Hispanic White (W) and 15 mixed (M) race/ethnicity girls, using dual energy x-ray absorptiometry (DXA) as the criterion method. Findings Black girls had similar %BF compared to other groups, yet were heavier per unit of height according to body mass index (BMI: kg·m−2) due to significantly greater FFM. BIA resistance index, age, weight and race/ethnicity were all significant predictors of FFM (R2 = 0.92, SEE = 1.81 kg). Standardized regression coefficients showed resistance index (0.63) and weight (0.34) were the most important predictors of FFM. Errors in %BF (~2%) and FFM (~1.0 kg) were greater when race/ethnicity was not included in the equation, particularly in Black girls. We conclude the BIA-composition relationship in adolescent girls is influenced by race, and consequently have developed new BIA equations for adolescent girls for predicting FFM and %BF. PMID:17848976

  18. Estimation of prevalence of sarcopenia by using a new bioelectrical impedance analysis in Chinese community-dwelling elderly people.

    PubMed

    Wang, Hui; Hai, Shan; Cao, Li; Zhou, Jianghua; Liu, Ping; Dong, Bi-Rong

    2016-12-28

    The aim of the present study was to validate the usefulness of the new octapolar multifrequency bioelectrical impedance analysis (BIA) for assessment of appendicular skeletal muscle mass (ASM) by comparing it with that of dual-energy X-ray absorptiometry (DXA) and to investigate the prevalence of sarcopenia in Chinese community-dwelling elderly according to Asian Working Group for Sarcopenia (AWGS) definition. A cross-sectional study was conducted in communities of Chengdu, China. A total of 944 community-dwelling elderly adults aged ≥60 years were included. ASM was measured by using DXA as a criterion method to validate a standing eight-electrode multifrequency BIA (InBody 720), followed by a further estimation of the prevalence of sarcopenia according the AWGS definition. In the Bland-Altman analysis, no significant difference was found between DXA and BIA based on the ASM measurements. The prevalence of AWGS-defined sarcopenia was 12.5% in the elderly women and 8.2% in the elderly men. BIA is suitable for body composition monitoring (ASM) in elderly Chinese as a fast, noninvasive, and convenient method; therefore, it may be a better choice in large epidemiological studies in the Chinese population. The prevalence of AWGS-defined sarcopenia was approximately 10.4% and increased with age in the Chinese community-dwelling elderly in this study.

  19. Phase Angle of Bioelectrical Impedance Analysis as Prognostic Factor in Palliative Care Patients at the National Cancer Institute in Mexico.

    PubMed

    Pérez Camargo, Dana A; Allende Pérez, Silvia R; Rivera Franco, Mónica M; Álvarez Licona, Nelson E; Urbalejo Ceniceros, Víctor I; Figueroa Baldenegro, Lilian E

    2017-01-01

    Patients with advanced cancer often experience symptoms of disease and treatment that contribute to distress such as weight loss, which is present in up to 85% of cancer patients. Palliative care in these patients focuses on care aimed at improving quality of life. Phase angle (PA) is obtained by bioelectric impedance analysis (BIA) and is associated with cellular function. It is considered a reliable marker of malnutrition. A low PA may suggest deterioration of the cell membrane, which in palliative patients may result in a short-term survival. The aim of this study was to associate PA and survival in palliative patients of the National Cancer Institute of Mexico. We included 452 patients (women, 56.4%); the average PA was 4.0°. The most frequent disease was gastric cancer (39.2%). Mean body mass index (BMI) was 22.84. The average survival of patients with PA ≤ 4° was 86 days, while in the group with PA > 4°, it was 163 days (P > 0.0001). PA showed significant positive correlation with survival time and BMI. Our results corroborate the reliability of PA in Mexican population, as an indicator of survival in palliative care patients compared to the reported literature in other countries.

  20. Electrical Properties Assessed by Bioelectrical Impedance Spectroscopy as Biomarkers of Age-related Loss of Skeletal Muscle Quantity and Quality.

    PubMed

    Yamada, Yosuke; Buehring, Bjoern; Krueger, Diane; Anderson, Rozalyn M; Schoeller, Dale A; Binkley, Neil

    2017-09-01

    Skeletal muscle, in addition to being comprised of a heterogeneous muscle fiber population, also includes extracellular components that do not contribute to positive tensional force production. Here we test segmental bioelectrical impedance spectroscopy (S-BIS) to assess muscle intracellular mass and composition. S-BIS can evaluate electrical properties that may be related to muscle force production. Muscle fiber membranes separate the intracellular components from the extracellular environment and consist of lipid bilayers which act as an electrical capacitor. We found that S-BIS measures accounted for ~85% of the age-related decrease in appendicular muscle power compared with only ~49% for dual-energy x-ray absorptiometry (DXA) measures. Indices of extracellular (noncontractile) and cellular (contractile) compartments in skeletal muscle tissues were determined using the Cole-Cole plot from S-BIS measures. Characteristic frequency, membrane capacitance, and phase angle determined by Cole-Cole analysis together presented a S-BIS complex model that explained ~79% of interindividual variance of leg muscle power. This finding underscores the value of S-BIS to measure muscle composition rather than lean mass as measured by DXA and suggests that S-BIS should be highly informative in skeletal muscle physiology. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Validity of Bioelectrical Impedance Analysis for Measuring Changes in Body Water and Percent Fat After Bariatric Surgery

    PubMed Central

    Widen, Elizabeth M.; Strain, Gladys; King, Wendy C.; Yu, Wenwen; Lin, Susan; Goodpaster, Bret; Thornton, John; Courcoulas, Anita; Pomp, Alfons

    2014-01-01

    Background Few studies have validated bioelectrical impedance analysis (BIA) following bariatric surgery. Methods We examined agreement of BIA (Tanita 310) measures of total body water (TBW) and percent body fat (%fat) before (T0) and 12 months (T12) after bariatric surgery, and change between T0 and T12 with reference measures: deuterium oxide dilution for TBW and three-compartment model (3C) for %fat in a subset of participants (n=50) of the Longitudinal Assessment of Bariatric Surgery-2. Results T0 to T12 median (IQR) change in deuterium TBW and 3C %fat was −6.4 L (6.4 L) and −14.8 % (13.4 %), respectively. There were no statistically significant differences between deuterium and BIA determined TBW [median (IQR) difference: T0 −0.1 L (7.1 L), p=0.75; T12 0.2 L (5.7 L), p=0.35; Δ 0.35 L(6.3 L), p=1.0]. Compared with 3C, BIA underestimated %fat at T0 and T12 [T0 −3.3 (5.6), p<0.001; T12 −1.7 (5.2), p=0.04] but not change [0.7 (8.2), p=0.38]. Except for %fat change, Bland-Altman plots indicated no proportional bias. However, 95 % limits of agreement were wide (TBW 15–22 L, %fat 19–20 %). Conclusions BIA may be appropriate for evaluating group level response among severely obese adults. However, clinically meaningful differences in the accuracy of BIA between individuals exist. PMID:24464517

  2. Predicting total weight of retail-ready lamb cuts from bioelectrical impedance measurements taken at the processing plant.

    PubMed

    Slanger, W D; Marchello, M J; Busboom, J R; Meyer, H H; Mitchell, L A; Hendrix, W F; Mills, R R; Warnock, W D

    1994-06-01

    Data of sixty finished, crossbred lambs were used to develop prediction equations of total weight of retail-ready cuts (SUM). These cuts were the leg, sirloin, loin, rack, shoulder, neck, riblets, shank, and lean trim (85/15). Measurements were taken on live lambs and on both hot and cold carcasses. A four-terminal bioelectrical impedance analyzer (BIA) was used to measure resistance (Rs, ohms) and reactance (Xc, ohms). Distances between detector terminals (L, centimeters) were recorded. Carcass temperatures (T, degrees C) at time of BIA readings were also recorded. The equation predicting SUM from cold carcass measurements (n = 53, R2 = .97) was .093 + .621 x weight-.0219 x Rs + .0248 x Xc + .182 x L-.338 x T. Resistance accounted for variability in SUM over and above weight and L (P = .0016). The above equation was used to rank cold carcasses in descending order of predicted SUM. An analogous ranking was obtained from a prediction equation that used weight only (R2 = .88). These rankings were divided into five categories: top 25%, middle 50%, bottom 25%, top 50%, and bottom 50%. Within-category differences in average fat cover, yield grade, and SUM as a percentage of cold carcass weight of carcasses not placed in the same category by both prediction equations were quantified with independent t-tests. These differences were statistically significant for all categories except middle 50%. This shows that BIA located those lambs that could more efficiently contribute to SUM because a higher portion of their weight was lean.

  3. Feasibility of bioelectrical impedance analysis in persons with severe intellectual and visual disabilities.

    PubMed

    Havinga-Top, A M; Waninge, A; van der Schans, C P; Jager-Wittenaar, H

    2015-12-01

    Body composition measurements provide important information about physical fitness and nutritional status. People with severe intellectual and visual disabilities (SIVD) have an increased risk for altered body composition. Bioelectrical impedance analysis (BIA) has been evidenced as a reliable and non-invasive method to asses body composition in healthy persons and various patient populations; however, currently, there is no feasible method available to determine body composition in people with SIVD. In this study, therefore, we aimed to assess the feasibility of BIA measurements in persons with SIVD. In 33 participants with SIVD and Gross Motor Functioning Classification System (GMFCS) Scale I, II, III, or IV, two BIA measurements were sequentially performed employing Resistance and Reactance in Ohm and fat-free mass (FFM) in kg as outcome variables, utilizing the Bodystat(®) QuadScan 4000. Feasibility was considered sufficient if ≥ 80% of the first measurement was performed successfully. Agreement between two repeated measurements was determined by using the paired t-test and Intraclass Correlation Coefficient (ICC; two way random, absolute agreement). Bland-Altman analyses were utilized to determine limits of agreement (LOAs) and systematic error. Agreement was considered acceptable if LOAs were <10% of the mean of the first measurement. The first BIA measurements were completed successfully in 88% of the participants. The paired t-test demonstrated no significant differences in Resistance, Reactance, and FFM between BIA Measurements 1 and 2 (P=0.140, 0.091, and 0.866). ICC was 0.965 (95% CI: 0.922-0.984) for Resistance; 0.858 (95% CI: 0.705-0.934) for Reactance; and 0.992 (95% CI: 0.982-0.996) for FFM. LOAs expressed as a percentage of the mean of Measurement 1 were 6.1% for Resistance, 17.6% for Reactance, and 3.8% for FFM. The results of this study suggest that BIA measurements seem to be feasible in persons with SIVD. Although these results require

  4. [Two compartment model of body composition and abdominal fat area in postmenopausal women - pilot study].

    PubMed

    Milewska, Magdalena; Mioduszewska, Milena; Pańczyk, Mariusz; Kucharska, Alicja; Sińska, Beata; Dąbrowska-Bender, Marta; Michota-Katulska, Ewa; Zegan, Magdalena; Szabla, Anna

    2016-01-01

    Both menopausal period and aging have influence on body composition, increase of total body fat and visceral fat in particular. We should be aware that changes in body composition, mainly fat translocation to abdominal region, can occur without significant changes in body weight. Therefore quantitative abdominal fat assessment should be our aim. Body composition analysis based on two compartment model and abdominal fat area assessment in cross section. Subjects in postmenopausal period (41 women) were recruited for this study and divided into 2 groups: group 1 - women aged 45-56 years and group 2 - women aged 57-79 years. Body composition analysis and abdominal fat area assessment were conducted by using bioelectrical impedance method with BioScan 920 (Maltron int.) accordingly with standardized procedure. Women in early postmenopausal stage (Group 1) had statistically significant lower total body fat percentage in comparison with women in late postmenopausal period (Group 2) (41.09 ± 7.72% vs. 50.7 ± 9.88%, p=0.0021). Also women in group 1 were characterized by significant lower visceral fat area (VAT) as well as subcutaneous fat area (SAT) in comparison with group 2 (respectively VAT 119.25 ± 30.09 cm2 vs. 199.36 ± 87.38 cm2, p=0.0011; SAT 175.19 ±57.67 cm2 vs. 223.4±74.29 cm2, p=0.0336). According to VAT criteria (>120 cm2), 44% of women in group 1 and 80% in group 2 had excess of visceral fat. Both total body fat and intra-abdominal fat increased with age, independently of weight changes.

  5. Method of recording bioelectrical signals using a capacitive coupling

    NASA Astrophysics Data System (ADS)

    Simon, V. A.; Gerasimov, V. A.; Kostrin, D. K.; Selivanov, L. M.; Uhov, A. A.

    2017-11-01

    In this article a technique for the bioelectrical signals acquisition by means of the capacitive sensors is described. A feedback loop for the ultra-high impedance biasing of the input instrumentation amplifier, which provides receiving of the electrical cardiac signal (ECS) through a capacitive coupling, is proposed. The mains 50/60 Hz noise is suppressed by a narrow-band stop filter with an independent notch frequency and quality factor tuning. Filter output is attached to a ΣΔ analog-to-digital converter (ADC), which acquires the filtered signal with a 24-bit resolution. Signal processing board is connected through universal serial bus interface to a personal computer, where ECS in a digital form is recorded and processed.

  6. Relationship between Body Mass Index (BMI) and body fat percentage, estimated by bioelectrical impedance, in a group of Sri Lankan adults: a cross sectional study.

    PubMed

    Ranasinghe, Chathuranga; Gamage, Prasanna; Katulanda, Prasad; Andraweera, Nalinda; Thilakarathne, Sithira; Tharanga, Praveen

    2013-09-03

    Body Mass Index (BMI) is used as a useful population-level measure of overweight and obesity. It is used as the same for both sexes and for all ages of adults. The relationship between BMI and body fat percentage (BF %) has been studied in various ethnic groups to estimate the capacity of BMI to predict adiposity. We aimed to study the BMI-BF% relationship, in a group of South Asian adults who have a different body composition compared to presently studied ethnic groups. We examined the influence of age, gender in this relationship and assessed its' linearity or curvilinearity. A cross sectional study was conducted, where adults of 18-83 years were grouped into young (18-39 years) middle aged (40-59 years) and elderly (>60 years). BF% was estimated from bioelectrical impedance analysis. Pearsons' correlation coefficient(r) was calculated to see the relationship between BMI-BF% in the different age groups. Multiple regression analysis was performed to determine the effect of age and gender in the relationship and polynomial regression was carried out to see its' linearity. The relationships between age-BMI, age-BF % were separately assessed. Out of 1114 participants, 49.1% were males. The study sample represented a wide range of BMI values (14.8-41.1 kg/m2,Mean 23.8 ± 4.2 kg/m2). A significant positive correlation was observed between BMI-BF%, in males (r =0.75, p < 0.01; SEE = 4.17) and in females (r = 0.82, p < 0.01; SEE = 3.54) of all ages. Effect of age and gender in the BMI-BF% relationship was significant (p < 0.001); with more effect from gender. Regression line found to be curvilinear in nature at higher BMI values where females (p < 0.000) having a better fit of the curve compared to males (p < 0.05). In both genders, with increase of age, BMI seemed to increase in curvilinear fashion, whereas BF% increased in a linear fashion. BMI strongly correlate with BF % estimated by bioelectrical impedance, in this sub

  7. Fat mass to fat-free mass ratio reference values from NHANES III using bioelectrical impedance analysis.

    PubMed

    Xiao, J; Purcell, S A; Prado, C M; Gonzalez, M C

    2017-10-06

    Low fat-free mass (FFM) or high fat mass (FM) are abnormal body composition phenotypes associated with morbidity. These conditions in combination lead to worse health outcomes, and can be identified by a high FM/FFM ratio. Here, we developed sex, age, and body mass index (BMI) stratified, population-based FM/FFM reference values using bioelectrical impedance analysis (BIA) measurements. White, non-Hispanic individuals aged 18-90 years old with data for weight, stature and BIA resistance measures from the third National Health and Nutrition Examination Survey (NHANES) III were included. Previously validated and sex-specific BIA prediction equations were used to calculate FM and FFM. FM/FFM values were generated at 5th, 50th and 95th percentiles for each sex, age (18-39.9, 40-59.9, 60-69.9 and 70-90 years), and BMI category (underweight, normal weight, overweight, class I/II and class III obesity). A total of 6372 individuals who had estimated FM and FFM values were identified (3366 females, 3006 males). Median values of FM/FFM were 0.24 and 0.40 for young (≤39.9 years) males and females with normal BMI, and 0.34 for males and 0.59 for females who were overweight. For elderly individuals aged >70 years, median FM/FFM for males and females were respectively 0.28 and 0.45 for those with normal BMI, and 0.37 and 0.61 for those in the overweight category. These FM/FFM reference values provide information on body composition characteristics that account for age, sex and BMI, which can be useful to identify individuals at risk for body composition abnormalities. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  8. Resting energy expenditure per lean body mass determined by indirect calorimetry and bioelectrical impedance analysis in cats.

    PubMed

    Center, S A; Warner, K L; Randolph, J F; Wakshlag, J J; Sunvold, G D

    2011-01-01

    Resting energy expenditure (REE) approximates ≥60% of daily energy expenditure (DEE). Accurate REE determination could facilitate sequential comparisons among patients and diseases if normalized against lean body mass (LBM). (1) Validate open-flow indirect calorimetry (IC) system and multifrequency bioelectrical impedance analysis (MF-BIA) to determine REE and LBM, respectively, in healthy nonsedated cats of varied body conditions; (2) normalize REE against LBM. Fifty-seven adult neutered domestic short-haired cats with stable BW. Continuous (45-min) IC-measurements determined least observed metabolism REE. Cage gas flow regulated with mass flow controllers was verified using nitrogen dilution; span gases calibrated gas measurements. Respiratory quotient accuracy was verified using alcohol combustion. IC-REE was compared to DEE, determined using doubly labeled water. MF-BIA LBM was validated against criterion references (deuterium, sodium bromide). Intra- and interassay variation was determined for IC and MF-BIA. Mean IC-REE (175 ± 38.7 kcal; 1.5-14% intra- and interassay CV%) represented 61 ± 14.3% of DEE. Best MF-BIA measurements were collected in sternal recumbency and with electrodes in neck-tail configuration. MF-BIA LBM was not significantly different from criterion references and generated LBM interassay CV% of 6.6-10.1%. Over- and underconditioned cats had significantly (P ≤ .05) lower and higher IC-REE (kcal/kg) respectively, compared with normal-conditioned cats. However, differences resolved with REE/LBM (approximating 53 ± 10.3 kcal/LBM [kg]). IC and MF-BIA validated herein reasonably estimate REE and LBM in cats. REE/LBM(kg) may permit comparison of energy utilization in sequential studies or among different cats. Copyright © 2011 by the American College of Veterinary Internal Medicine.

  9. Determination of body composition using air displacement plethysmography, anthropometry and bio-electrical impedance in rural elderly Mexican men and women.

    PubMed

    Aleman-Mateo, H; Esparza Romero, J; Macias Morales, N; Salazar, G; Wyatt, J; Valencia, M E

    2004-01-01

    Air displacement plethysmography with the BOD-POD is a new densitometry technique, and has been found to be an accurate method to measure body composition. The aim of this study was to assess body composition in a group of free living healthy subjects 60 years of age or older from a rural area of Northwest Mexico, and to evaluate body composition by anthropometry and bioelectrical impedance (BIA) using equations reported for other elderly populations. Body composition was evaluated in 21 women and 26 men with the BOD-POD, by anthropometry, and BIA and compared to different equations using the Bland- Altman procedure. Body fat in elderly women and men was 42.7 and 30.2 % respectively. In women, Segal's equation using BIA 1, based on standing height, showed no significant differences with the BOD-POD. There was satisfactory agreement between Segal's equation and BOD-POD. In men similar results was found with Deurenberg's equation using B1A 2 based on recumbent length. Segal's and Deurenberg's equations were accurate and precise for the estimation of body fat in the elderly of this study. The use of these equations could improve the estimation of body composition for similar elderly subjects. Further studies are recommended with a larger size samples to include elderly subjects from other Latin American countries.

  10. Comparison of Standing Posture Bioelectrical Impedance Analysis with DXA for Body Composition in a Large, Healthy Chinese Population.

    PubMed

    Chen, Kuen-Tsann; Chen, Yu-Yawn; Wang, Chia-Wei; Chuang, Chih-Lin; Chiang, Li-Ming; Lai, Chung-Liang; Lu, Hsueh-Kuan; Dwyer, Gregory B; Chao, Shu-Ping; Shih, Ming-Kuei; Hsieh, Kuen-Chang

    2016-01-01

    Bioelectrical impedance analysis (BIA) is a common method for assessing body composition in research and clinical trials. BIA is convenient but when compared with other reference methods, the results have been inconclusive. The level of obesity degree in subjects is considered to be an important factor affecting the accuracy of the measurements. A total of 711 participants were recruited in Taiwan and were sub-grouped by gender and levels of adiposity. Regression analysis and Bland-Altman analysis were used to evaluate the agreement of the measured body fat percentage (BF%) between BIA and DXA. The BF% measured by the DXA and BIA methods (Tanita BC-418) were expressed as BF%DXA and BF%BIA8, respectively. A one-way ANOVA was used to test the differences in BF% measurements by gender and levels of adiposity. The estimated BF%BIA8 and BF%DXA in the all subjects, male and female groups were all highly correlated (r = 0.934, 0.901, 0.916, all P< 0.001). The average estimated BF%BIA8 (22.54 ± 9.48%) was significantly lower than the average BF%DXA (26.26 ± 11.18%). The BF%BIA8 was overestimated in the male subgroup (BF%DXA< 15%), compared to BF%DXA by 0.45%, respectively. In the other subgroups, the BF%BIA8 values were all underestimated. Standing BIA estimating body fat percentage in Chinese participants have a high correlation, but underestimated on normal and high obesity degree in both male and female subjects.

  11. Making the invisible visible: bioelectrical impedance analysis demonstrates unfavourable body composition in rheumatoid arthritis patients in clinical practice.

    PubMed

    Konijn, N P C; van Tuyl, L H D; Bultink, I E M; Lems, W F; Earthman, C P; van Bokhorst-de van der Schueren, M A E

    2014-01-01

    To examine differences between the assessment of body composition by body mass index (BMI) and bioelectrical impedance analysis (BIA) in patients with rheumatoid arthritis (RA). The body composition of RA patients was assessed during their visit to the outpatient department of a Dutch academic hospital using BMI, fat-free mass index (FFMI), and fat mass index (FMI). FFMI and FMI were determined by single-frequency BIA. Sixty-five consecutive RA patients (83% women, mean age 58 years, median disease duration 7 years) with moderately active disease [mean Disease Activity Score using 28 joint counts (DAS28) = 3.40; mean Rheumatoid Arthritis Disease Activity Index (RADAI) score = 3.49] and moderate disability [mean Health Assessment Questionnaire (HAQ) score = 0.87] were included. Based on BMI, 2% of our study population were underweight, 45% had a healthy body composition, and 54% were overweight or obese. Based on BIA, 18% of the patients showed a low FFMI and 74% had a high or very high FMI. Low FFMI was found in 44% of the women with a normal BMI, and high FMI was found in 40% of the women and 75% of the men with a normal BMI. A high frequency of unfavourable body composition, predominantly reduced FFMI and elevated FMI, was found in a cohort of RA patients with moderately active disease, turning BMI into an unreliable method for assessment of body composition in RA. BIA, however, might be the preferred method to assess FFMI and FMI in RA patients in clinical practice, as it is easy to use and relatively inexpensive.

  12. Comparison of Standing Posture Bioelectrical Impedance Analysis with DXA for Body Composition in a Large, Healthy Chinese Population

    PubMed Central

    Chen, Kuen-Tsann; Chen, Yu-Yawn; Wang, Chia-Wei; Chuang, Chih-Lin; Chiang, Li-Ming; Lai, Chung-Liang; Lu, Hsueh-Kuan; Dwyer, Gregory B.; Chao, Shu-Ping; Shih, Ming-Kuei; Hsieh, Kuen-Chang

    2016-01-01

    Bioelectrical impedance analysis (BIA) is a common method for assessing body composition in research and clinical trials. BIA is convenient but when compared with other reference methods, the results have been inconclusive. The level of obesity degree in subjects is considered to be an important factor affecting the accuracy of the measurements. A total of 711 participants were recruited in Taiwan and were sub-grouped by gender and levels of adiposity. Regression analysis and Bland-Altman analysis were used to evaluate the agreement of the measured body fat percentage (BF%) between BIA and DXA. The BF% measured by the DXA and BIA methods (Tanita BC-418) were expressed as BF%DXA and BF%BIA8, respectively. A one-way ANOVA was used to test the differences in BF% measurements by gender and levels of adiposity. The estimated BF%BIA8 and BF%DXA in the all subjects, male and female groups were all highly correlated (r = 0.934, 0.901, 0.916, all P< 0.001). The average estimated BF%BIA8 (22.54 ± 9.48%) was significantly lower than the average BF%DXA (26.26 ± 11.18%). The BF%BIA8 was overestimated in the male subgroup (BF%DXA< 15%), compared to BF%DXA by 0.45%, respectively. In the other subgroups, the BF%BIA8 values were all underestimated. Standing BIA estimating body fat percentage in Chinese participants have a high correlation, but underestimated on normal and high obesity degree in both male and female subjects. PMID:27467065

  13. Accuracy of skinfold and bioelectrical impedance assessments of body fat percentage in ambulatory individuals with cerebral palsy.

    PubMed

    Oeffinger, Donna J; Gurka, Matthew J; Kuperminc, Michelle; Hassani, Sahar; Buhr, Neeley; Tylkowski, Chester

    2014-05-01

    This study assessed the accuracy of measurements of body fat percentage in ambulatory individuals with cerebral palsy (CP) from bioelectrical impedance analysis (BIA) and skinfold equations. One hundred and twenty-eight individuals (65 males, 63 females; mean age 12y, SD 3, range 6-18y) with CP (Gross Motor Function Classification System [GMFCS] levels I (n=6), II (n=46), and III (n=19) participated. Body fat percentage was estimated from (1) BIA using standing height and estimated heights (knee height and tibial length) and (2) triceps and subscapular skinfolds using standard and CP-specific equations. All estimates of body fat percentage were compared with body fat percentage from dual-energy X-ray absorptiometry (DXA) scans. Differences between DXA, BIA, and skinfold body fat percentage were analyzed by comparing mean differences. Agreement was assessed by Bland-Altman plots and concordance correlation coefficients (CCC). BMI was moderately correlated with DXA (Pearson's r=0.53). BIA body fat percentage was significantly different from DXA when using estimated heights (95% confidence intervals [CIs] do not contain 0) but not standing height (95% CI -1.9 to 0.4). CCCs for all BIA comparisons indicated good to excellent agreement (0.75-0.82) with DXA. Body fat percentage from skinfold measurements and CP-specific equations was not significantly different from DXA (mean 0.8%; SD 5.3%; 95% CI -0.2 to 1.7) and demonstrated strong agreement with DXA (CCC 0.86). Accurate measures of body fat percentage can be obtained using BIA and two skinfold measurements (CP-specific equations) in ambulatory individuals with CP. These findings should encourage assessments of body fat in clinical and research practices. © 2013 Mac Keith Press.

  14. Obesity in Korean pre-adolescent school children: comparison of various anthropometric measurements based on bioelectrical impedance analysis.

    PubMed

    Yoo, S; Lee, S-Y; Kim, K-N; Sung, E

    2006-07-01

    To examine the relationships between body mass index (BMI), percentage-weight-for-height (PWH) and percentage body fat (PBF), and to compare their validity based on PBF with the BMI criteria of International Obesity Task Force (IOTF) for childhood obesity in Korean pre-adolescent school children. Statistical comparative analysis for anthropometric measures. Korean pre-adolescent children (438 boys and 454 girls, aged 8-12 years, mean BMI 19.5+/-3.4 kg/m2). Body mass index and PWH were calculated as body size indices from height and weight. Hand-to-foot bioelectrical impedance analysis (BIA) was performed to obtain PBF values, with obese children defined as PBF above 35%. Sensitivity and specificity were displayed with the gold standard of PBF, and receiver operating characteristic (ROC) curves were used to assess the performance of BMI and PWH in detecting obesity. The prevalence of obesity varied by the criteria: 18.8% by Korean BMI standards for 95 percentile, 11% by the IOTF-BMI 30 kg/m2 and 29.4% by Korean PWH cutoffs. Body mass index and PWH were significantly correlated with PBF after adjusting for age, 0.910 (P<0.01) and 0.915 (P<0.01), respectively. The sensitivity and specificity of the PWH cutoffs were 0.909 and 0.882, respectively. The local BMI 95 percentiles had lower sensitivity (0.714) and specificity (0.790). The IOTF-BMI definition showed much lower sensitivity (0.457) and higher specificity (0.990). The BMI cutoffs corresponding with the highest accuracy were smaller than IOTF-BMI 30 kg/m2 for all age groups in both boys and girls. The prevalence of obesity among Korean pre-adolescent children widely varied according to the diagnostic criteria applied. Universally recommended cutoffs for children by IOTF showed the lowest sensitivity among the criteria used, and may therefore underestimate obesity in this population.

  15. Bioelectrical Impedance Phase Angle as an Indicator of Malnutrition in Hospitalized Children with Diagnosed Inflammatory Bowel Diseases-A Case Control Study.

    PubMed

    Więch, Paweł; Dąbrowski, Mariusz; Bazaliński, Dariusz; Sałacińska, Izabela; Korczowski, Bartosz; Binkowska-Bury, Monika

    2018-04-17

    The phase angle (PhA) seems to be a reliable screening tool for the identification of malnutrition risk in hospitalized children with inflammatory bowel disease (IBD). The aim of the present study was to assess the body composition and nutritional status of hospitalized children and adolescents with IBD by using bioelectrical impedance analysis (BIA) with phase angle (PhA) calculation, which has not been evaluated in hospitalized children with IBD yet. A total of 59 children and adolescents aged 4–18 years, with IBD: 34 ulcerative colitis (UC) and 25 Crohn’s disease (CD) were included in the study. The control group consisted of healthy children and adolescents, strictly matched for gender and age in a 1:1 case-control manner. In both groups, BIA was performed and PhA was calculated. IBD patients had significantly lower PhA (UC: 5.34 ± 1.34 vs. 5.96 ± 0.76, p = 0.040; CD: 5.16 ± 1.18 vs. 5.90 ± 0.62, p = 0.009) compared to the control subjects. Significant changes in selected body composition parameters were observed particularly in CD, especially in fat free mass components. Lower phase angle score together with lower body composition parameters and selected nutrition indicators in children and adolescents with IBD demonstrate their worse nutritional and functional status compared to healthy subjects.

  16. Comparison of air-displacement plethysmography with hydrostatic weighing and bioelectrical impedance analysis for the assessment of body composition in healthy adults.

    PubMed

    Biaggi, R R; Vollman, M W; Nies, M A; Brener, C E; Flakoll, P J; Levenhagen, D K; Sun, M; Karabulut, Z; Chen, K Y

    1999-05-01

    Over the past decade, considerable attention has been paid to accurately measuring body composition in diverse populations. Recently, the use of air-displacement plethysmography (AP) was proposed as an accurate, comfortable, and accessible method of body-composition analysis. The purpose of this study was to compare measurements of percentage body fat (%BF) by AP and 2 other established techniques, hydrostatic weighing (HW) and bioelectrical impedance analysis (BIA), in adults. The sample consisted of healthy men (n = 23) and women (n = 24). %BF was measured by AP, HW, and BIA. In the total group, %BF(AP) (25.0+/-8.9%) was not significantly different from %BF(HW) (25.1+/-7.7%) or %BF(BIA) (23.9+/-7.7%), and %BF(AP) was significantly correlated with %BF(HW) (r = 0.944, P < 0.001) and with %BF(BIA) (r = 0.859, P < 0.01). Compared with HW, AP underestimated %BF in men (by -1.24+/-3.12%) but overestimated %BF in women (by 1.02+/-2.48%), indicating a significant sex effect (P < 0.05). The differences in estimation between AP and BIA and between BIA and HW were not significantly different between the sexes. AP is an accurate method for assessing body composition in healthy adults. Future studies should assess further the cause of the individual variations with this new method.

  17. Phase angle assessment by bioelectrical impedance analysis and its predictive value for malnutrition risk in hospitalized geriatric patients.

    PubMed

    Varan, Hacer Dogan; Bolayir, Basak; Kara, Ozgur; Arik, Gunes; Kizilarslanoglu, Muhammet Cemal; Kilic, Mustafa Kemal; Sumer, Fatih; Kuyumcu, Mehmet Emin; Yesil, Yusuf; Yavuz, Burcu Balam; Halil, Meltem; Cankurtaran, Mustafa

    2016-12-01

    Phase angle (PhA) value determined by bioelectrical impedance analysis (BIA) is an indicator of cell membrane damage and body cell mass. Recent studies have shown that low PhA value is associated with increased nutritional risk in various group of patients. However, there have been only a few studies performed globally assessing the relationship between nutritional risk and PhA in hospitalized geriatric patients. The aim of the study is to evaluate the predictive value of the PhA for malnutrition risk in hospitalized geriatric patients. One hundred and twenty-two hospitalized geriatric patients were included in this cross-sectional study. Comprehensive geriatric assessment tests and BIA measurements were performed within the first 48 h after admission. Nutritional risk state of the patients was determined with NRS-2002. Phase angle values of the patients with malnutrition risk were compared with the patients that did not have the same risk. The independent variables for predicting malnutrition risk were determined. SPSS version 15 was utilized for the statistical analyzes. The patients with malnutrition risk had significantly lower phase angle values than the patients without malnutrition risk (p = 0.003). ROC curve analysis suggested that the optimum PhA cut-off point for malnutrition risk was 4.7° with 79.6 % sensitivity, 64.6 % specificity, 73.9 % positive predictive value, and 73.9 % negative predictive value. BMI, prealbumin, PhA, and Mini Mental State Examination Test scores were the independent variables for predicting malnutrition risk. PhA can be a useful, independent indicator for predicting malnutrition risk in hospitalized geriatric patients.

  18. Cross-mode bioelectrical impedance analysis in a standing position for estimating fat-free mass validated against dual-energy x-ray absorptiometry.

    PubMed

    Huang, Ai-Chun; Chen, Yu-Yawn; Chuang, Chih-Lin; Chiang, Li-Ming; Lu, Hsueh-Kuan; Lin, Hung-Chi; Chen, Kuen-Tsann; Hsiao, An-Chi; Hsieh, Kuen-Chang

    2015-11-01

    Bioelectrical impedance analysis (BIA) is commonly used to assess body composition. Cross-mode (left hand to right foot, Z(CR)) BIA presumably uses the longest current path in the human body, which may generate better results when estimating fat-free mass (FFM). We compared the cross-mode with the hand-to-foot mode (right hand to right foot, Z(HF)) using dual-energy x-ray absorptiometry (DXA) as the reference. We hypothesized that when comparing anthropometric parameters using stepwise regression analysis, the impedance value from the cross-mode analysis would have better prediction accuracy than that from the hand-to-foot mode analysis. We studied 264 men and 232 women (mean ages, 32.19 ± 14.95 and 34.51 ± 14.96 years, respectively; mean body mass indexes, 24.54 ± 3.74 and 23.44 ± 4.61 kg/m2, respectively). The DXA-measured FFMs in men and women were 58.85 ± 8.15 and 40.48 ± 5.64 kg, respectively. Multiple stepwise linear regression analyses were performed to construct sex-specific FFM equations. The correlations of FFM measured by DXA vs. FFM from hand-to-foot mode and estimated FFM by cross-mode were 0.85 and 0.86 in women, with standard errors of estimate of 2.96 and 2.92 kg, respectively. In men, they were 0.91 and 0.91, with standard errors of the estimates of 3.34 and 3.48 kg, respectively. Bland-Altman plots showed limits of agreement of -6.78 to 6.78 kg for FFM from hand-to-foot mode and -7.06 to 7.06 kg for estimated FFM by cross-mode for men, and -5.91 to 5.91 and -5.84 to 5.84 kg, respectively, for women. Paired t tests showed no significant differences between the 2 modes (P > .05). Hence, cross-mode BIA appears to represent a reasonable and practical application for assessing FFM in Chinese populations. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. An evaluation of a bioelectrical impedance analyser for the estimation of body fat content.

    PubMed Central

    Maughan, R J

    1993-01-01

    Measurement of body composition is an important part of any assessment of health or fitness. Hydrostatic weighing is generally accepted as the most reliable method for the measurement of body fat content, but is inconvenient. Electrical impedance analysers have recently been proposed as an alternative to the measurement of skinfold thickness. Both these latter methods are convenient, but give values based on estimates obtained from population studies. This study compared values of body fat content obtained by hydrostatic weighing, skinfold thickness measurement and electrical impedance on 50 (28 women, 22 men) healthy volunteers. Mean(s.e.m.) values obtained by the three methods were: hydrostatic weighing, 20.5(1.2)%; skinfold thickness, 21.8(1.0)%; impedance, 20.8(0.9)%. The results indicate that the correlation between the skinfold method and hydrostatic weighing (0.931) is somewhat higher than that between the impedance method and hydrostatic weighing (0.830). This is, perhaps, not surprising given the fact that the impedance method is based on an estimate of total body water which is then used to calculate body fat content. The skinfold method gives an estimate of body density, and the assumptions involved in the conversion from body density to body fat content are the same for both methods. PMID:8457817

  20. Validation of bioelectrical impedance analysis for total body water assessment against the deuterium dilution technique in Asian children.

    PubMed

    Liu, A; Byrne, N M; Ma, G; Nasreddine, L; Trinidad, T P; Kijboonchoo, K; Ismail, M N; Kagawa, M; Poh, B K; Hills, A P

    2011-12-01

    To develop and cross-validate bioelectrical impedance analysis (BIA) prediction equations of total body water (TBW) and fat-free mass (FFM) for Asian pre-pubertal children from China, Lebanon, Malaysia, Philippines and Thailand. Height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8-10 years from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed using stepwise multiple regression analysis and cross-validated using the Bland-Altman approach. The BIA prediction equation for the estimation of TBW was as follows: TBW=0.231 × height(2)/resistance+0.066 × height+0.188 × weight+0.128 × age+0.500 × sex-0.316 × Thais-4.574 (R (2)=88.0%, root mean square error (RMSE)=1.3 kg), and for the estimation of FFM was as follows: FFM=0.299 × height(2)/resistance+0.086 × height+0.245 × weight+0.260 × age+0.901 × sex-0.415 × ethnicity (Thai ethnicity =1, others = 0)-6.952 (R (2)=88.3%, RMSE=1.7 kg). No significant difference between measured and predicted values for the whole cross-validation sample was found. However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels whereas underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM was also valid at each body mass index category. Ethnicity influences the relationship between BIA and body composition in Asian pre-pubertal children. The newly developed BIA prediction equations are valid for use in Asian pre-pubertal children.

  1. Residential neighborhood, geographic work environment, and work economic sector: associations with body fat measured by bioelectrical impedance in the RECORD Study.

    PubMed

    Lewin, Antoine; Pannier, Bruno; Méline, Julie; Karusisi, Noëlla; Thomas, Frédérique; Chaix, Basile

    2014-03-01

    Studies of associations between geographic environment and obesity have mostly examined body mass index and focused on residential neighborhoods. We investigated associations between residential neighborhoods, geographic work environments, and work economic sectors and the fat mass index (FMI) and percentage of fat mass (%FM). Data on 4331 participants from the French RECORD Study geolocated at their residence and workplace were analyzed. Body composition was assessed by bioelectrical impedance analyzers. Multilevel linear regression was used to investigate the determinants of FMI and %FM. After adjustment, among men, the FMI and %FM increased independently with decreasing density of population and educational level in the residential neighborhood. Among women, the residential educational level was related to the FMI and %FM. Among men, a higher FMI and %FM were observed among participants working in the construction and transportation/communication sectors than in the education sector. For women, the FMI was higher among participants working in the public administration and health/social work sectors than in the transport/communication sector. A long home-work distance was associated with a higher FMI among women. There was evidence that body mass index cannot fully capture work economic sector effects on fat mass. Public health interventions to reduce social/territorial disparities in obesity should also consider the different contexts to which the participants belong, such as residential environments and work economic sectors. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Hand-to-Hand Model for Bioelectrical Impedance Analysis to Estimate Fat Free Mass in a Healthy Population

    PubMed Central

    Lu, Hsueh-Kuan; Chiang, Li-Ming; Chen, Yu-Yawn; Chuang, Chih-Lin; Chen, Kuen-Tsann; Dwyer, Gregory B.; Hsu, Ying-Lin; Chen, Chun-Hao; Hsieh, Kuen-Chang

    2016-01-01

    This study aimed to establish a hand-to-hand (HH) model for bioelectrical impedance analysis (BIA) fat free mass (FFM) estimation by comparing with a standing position hand-to-foot (HF) BIA model and dual energy X-ray absorptiometry (DXA); we also verified the reliability of the newly developed model. A total of 704 healthy Chinese individuals (403 men and 301 women) participated. FFM (FFMDXA) reference variables were measured using DXA and segmental BIA. Further, regression analysis, Bland–Altman plots, and cross-validation (2/3 participants as the modeling group, 1/3 as the validation group; three turns were repeated for validation grouping) were conducted to compare tests of agreement with FFMDXA reference variables. In male participants, the hand-to-hand BIA model estimation equation was calculated as follows: FFMmHH = 0.537 h2/ZHH − 0.126 year + 0.217 weight + 18.235 (r2 = 0.919, standard estimate of error (SEE) = 2.164 kg, n = 269). The mean validated correlation coefficients and limits of agreement (LOAs) of the Bland–Altman analysis of the calculated values for FFMmHH and FFMDXA were 0.958 and −4.369–4.343 kg, respectively, for hand-to-foot BIA model measurements for men; the FFM (FFMmHF) and FFMDXA were 0.958 and −4.356–4.375 kg, respectively. The hand-to-hand BIA model estimating equation for female participants was FFMFHH = 0.615 h2/ZHH − 0.144 year + 0.132 weight + 16.507 (r2 = 0.870, SEE = 1.884 kg, n = 201); the three mean validated correlation coefficient and LOA for the hand-to-foot BIA model measurements for female participants (FFMFHH and FFMDXA) were 0.929 and −3.880–3.886 kg, respectively. The FFMHF and FFMDXA were 0.942 and −3.511–3.489 kg, respectively. The results of both hand-to-hand and hand-to-foot BIA models demonstrated similar reliability, and the hand-to-hand BIA models are practical for assessing FFM. PMID:27775642

  3. Hand-to-Hand Model for Bioelectrical Impedance Analysis to Estimate Fat Free Mass in a Healthy Population.

    PubMed

    Lu, Hsueh-Kuan; Chiang, Li-Ming; Chen, Yu-Yawn; Chuang, Chih-Lin; Chen, Kuen-Tsann; Dwyer, Gregory B; Hsu, Ying-Lin; Chen, Chun-Hao; Hsieh, Kuen-Chang

    2016-10-21

    This study aimed to establish a hand-to-hand (HH) model for bioelectrical impedance analysis (BIA) fat free mass (FFM) estimation by comparing with a standing position hand-to-foot (HF) BIA model and dual energy X-ray absorptiometry (DXA); we also verified the reliability of the newly developed model. A total of 704 healthy Chinese individuals (403 men and 301 women) participated. FFM (FFM DXA ) reference variables were measured using DXA and segmental BIA. Further, regression analysis, Bland-Altman plots, and cross-validation (2/3 participants as the modeling group, 1/3 as the validation group; three turns were repeated for validation grouping) were conducted to compare tests of agreement with FFM DXA reference variables. In male participants, the hand-to-hand BIA model estimation equation was calculated as follows: FFM m HH = 0.537 h²/Z HH - 0.126 year + 0.217 weight + 18.235 ( r ² = 0.919, standard estimate of error (SEE) = 2.164 kg, n = 269). The mean validated correlation coefficients and limits of agreement (LOAs) of the Bland-Altman analysis of the calculated values for FFM m HH and FFM DXA were 0.958 and -4.369-4.343 kg, respectively, for hand-to-foot BIA model measurements for men; the FFM (FFM m HF ) and FFM DXA were 0.958 and -4.356-4.375 kg, respectively. The hand-to-hand BIA model estimating equation for female participants was FFM F HH = 0.615 h²/Z HH - 0.144 year + 0.132 weight + 16.507 ( r ² = 0.870, SEE = 1.884 kg, n = 201); the three mean validated correlation coefficient and LOA for the hand-to-foot BIA model measurements for female participants (FFM F HH and FFM DXA ) were 0.929 and -3.880-3.886 kg, respectively. The FFM HF and FFM DXA were 0.942 and -3.511-3.489 kg, respectively. The results of both hand-to-hand and hand-to-foot BIA models demonstrated similar reliability, and the hand-to-hand BIA models are practical for assessing FFM.

  4. Bioelectrical impedance phase angle relates to function, disease severity and prognosis in stable chronic obstructive pulmonary disease.

    PubMed

    Maddocks, Matthew; Kon, Samantha S C; Jones, Sarah E; Canavan, Jane L; Nolan, Claire M; Higginson, Irene J; Gao, Wei; Polkey, Michael I; Man, William D-C

    2015-12-01

    Bioelectrical impedance analysis (BIA) provides a simple method to assess changes in body composition. Raw BIA variables such as phase angle provide direct information on cellular mass and integrity, without the assumptions inherent in estimating body compartments, e.g. fat-free mass (FFM). Phase angle is a strong functional and prognostic marker in many disease states, but data in COPD are lacking. Our aims were to describe the measurement of phase angle in patients with stable COPD and determine the construct and discriminate validity of phase angle by assessing its relationship with established markers of function, disease severity and prognosis. 502 outpatients with stable COPD were studied. Phase angle and FFM by BIA, quadriceps strength (QMVC), 4-m gait speed (4MGS), 5 sit-to-stand time (5STS), incremental shuttle walk (ISW), and composite prognostic indices (ADO, iBODE) were measured. Patients were stratified into normal and low phase angle and FFM index. Phase angle correlated positively with FFM and functional outcomes (r = 0.35-0.66, p < 0.001) and negatively with prognostic indices (r = -0.35 to -0.48, p < 0.001). In regression models, phase angle was independently associated with ISW, ADO and iBODE whereas FFM was removed. One hundred and seventy patients (33.9% [95% CI, 29.9-38.1]) had a low phase angle. Phenotypic characteristics included lower QMVC, ISW, and 4MGS, higher 5STS, ADO and iBODE scores, and more exacerbations and hospital days in past year. The proportion of patients to have died was significantly higher in patients with low phase angle compared to those with normal phase angle (8.2% versus 3.6%, p = 0.02). Phase angle relates to markers of function, disease severity and prognosis in patients with COPD. As a directly measured variable, phase angle offers more useful information than fat-free mass indices. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  5. Body composition of adult cystic fibrosis patients and control subjects as determined by densitometry, bioelectrical impedance, total-body electrical conductivity, skinfold measurements, and deuterium oxide dilution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Newby, M.J.; Keim, N.L.; Brown, D.L.

    1990-08-01

    This study contrasts body compositions (by six methods) of eight cystic fibrosis (CF) subjects with those of eight control subjects matched for age, height, and sex. CF subjects weighed 84% as much as control subjects. Densitometry and two bioelectrical impedance-analysis methods suggested that reduced CF weights were due to less lean tissue (10.7, 9.5, and 10.4 kg). Total-body electrical conductivity (TOBEC) and skinfold-thickness measurements indicated that CF subjects were leaner than control subjects and had less fat (5.4 and 3.6 kg) and less lean (5.2 and 7 kg) tissue. D2O dilution showed a pattern similar to TOBEC (8.3 kg lessmore » lean, 2.7 kg less fat tissue). Densitometry estimates of fat (mass and percent) were not correlated (r less than 0.74, p greater than 0.05) with any other method for CF subjects but were correlated with all other methods for control subjects. CF subjects contained less fat and lean tissue than did control subjects. Densitometry by underwater weighing is unsuitable for assessing body composition of CF patients.« less

  6. Characterization of bioelectric potentials

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles C. (Inventor); Wheeler, Kevin R. (Inventor)

    2004-01-01

    Method and system for recognizing and characterizing bioelectric potential or electromyographic (EMG) signals associated with at least one of a coarse gesture and a fine gesture that is performed by a person, and use of the bioelectric potentials to enter data and/or commands into an electrical and/or mechanical instrument. As a gesture is performed, bioelectric signals that accompany the gesture are subjected to statistical averaging, within selected time intervals. Hidden Markov model analysis is applied to identify hidden, gesture-related states that are present. A metric is used to compare signals produced by a volitional gesture (not yet identified) with corresponding signals associated with each of a set of reference gestures, and the reference gesture that is closest to the volitional gesture is identified. Signals representing the volitional gesture are analyzed and compared with a database of reference gestures to determine if the volitional gesture is likely to be one of the reference gestures. Electronic and/or mechanical commands needed to carry out the gesture may be implemented at an interface to control an instrument. Applications include control of an aircraft, entry of data from a keyboard or other data entry device, and entry of data and commands in extreme environments that interfere with accurate entry.

  7. Accuracy of Bioelectrical Impedance Analysis in Estimated Longitudinal Fat-Free Mass Changes in Male Army Cadets.

    PubMed

    Langer, Raquel D; Matias, Catarina N; Borges, Juliano H; Cirolini, Vagner X; Páscoa, Mauro A; Guerra-Júnior, Gil; Gonçalves, Ezequiel M

    2018-03-26

    Bioelectrical impedance analysis (BIA) is a practical and rapid method for making a longitudinal analysis of changes in body composition. However, most BIA validation studies have been performed in a clinical population and only at one moment, or point in time (cross-sectional study). The aim of this study is to investigate the accuracy of predictive equations based on BIA with regard to the changes in fat-free mass (FFM) in Brazilian male army cadets after 7 mo of military training. The values used were determined using dual-energy X-ray absorptiometry (DXA) as a reference method. The study included 310 male Brazilian Army cadets (aged 17-24 yr). FFM was measured using eight general predictive BIA equations, with one equation specifically applied to this population sample, and the values were compared with results obtained using DXA. The student's t-test, adjusted coefficient of determination (R2), standard error of estimation (SEE), Lin's approach, and the Bland-Altman test were used to determine the accuracy of the predictive BIA equations used to estimate FFM in this population and between the two moments (pre- and post-moment). The FFM measured using the nine predictive BIA equations, and determined using DXA at the post-moment, showed a significant increase when compared with the pre-moment (p < 0.05). All nine predictive BIA equations were able to detect FFM changes in the army cadets between the two moments in a very similar way to the reference method (DXA). However, only the one BIA equation specific to this population showed no significant differences in the FFM estimation between DXA at pre- and post-moment of military routine. All predictive BIA equations showed large limits of agreement using the Bland-Altman approach. The eight general predictive BIA equations used in this study were not found to be valid for analyzing the FFM changes in the Brazilian male army cadets, after a period of approximately 7 mo of military training. Although the BIA

  8. Bioelectric impedance and hydrostatic weighing with and without head submersion in persons who are morbidly obese.

    PubMed

    Heath, E M; Adams, T D; Daines, M M; Hunt, S C

    1998-08-01

    To compare hydrostatic weighing with and without head submersion and bioelectric impedance analysis (BIA) for measurement of body composition of persons who are morbidly obese. Body composition was determined using 3 methods: hydrostatic weighing with and without head submersion and BIA. Residual volume for the hydrostatic weighing calculation was determined by body plethysmography. Subjects were 16 morbidly obese men (142.5 kg mean body weight) and 30 morbidly obese women (125.9 kg mean body weight) living in the Salt Lake County, Utah, area. Morbid obesity was defined as 40 kg or more over ideal weight. One-way, repeated-measures analysis of variance was followed by Scheffé post hoc tests; body-fat measurement method served as the repeated variable and percentage of body fat as the dependent variable. Men and women were analyzed separately. In addition, degree of agreement between the 3 methods of determining body composition was determined. A regression equation was used to calculate body density for hydrostatic weighing without head submersion. Two new BIA regression equations were developed from the data of the 16 men and 30 women. Values for percentage body fat from hydrostatic weighing with and without head submersion (41.8% vs 41.7%, respectively) were the same for men but differed for women (52.2% vs 49.4%, respectively, P < .0001). Values for body fat percentage measured by BIA were significantly lower for men (36.1%) and women (43.1%) (for both, P < .0001) compared with values from hydrostatic weighing methods. BIA underpredicted percentage body fat by a mean of 5.7% in men and 9.1% in women compared with the traditional hydrostatic weighing method. BIA tended to underpredict the measurement of percentage body fat in male and female subjects who were morbidly obese. Hydrostatic weighing without head submersion provides an accurate, acceptable, and convenient alternative method for body composition assessment of the morbidly obese population in

  9. Bioelectrical impedance analysis-derived phase angle at admission as a predictor of 90-day mortality in intensive care patients.

    PubMed

    Stapel, Sandra N; Looijaard, Wilhelmus G P M; Dekker, Ingeborg M; Girbes, Armand R J; Weijs, Peter J M; Oudemans-van Straaten, Heleen M

    2018-05-11

    A low bioelectrical impedance analysis (BIA)-derived phase angle (PA) predicts morbidity and mortality in different patient groups. An association between PA and long-term mortality in ICU patients has not been demonstrated before. The purpose of the present study was to determine whether PA on ICU admission independently predicts 90-day mortality. This prospective observational study was performed in a mixed university ICU. BIA was performed in 196 patients within 24 h of ICU admission. To test the independent association between PA and 90-day mortality, logistic regression analysis was performed using the APACHE IV predicted mortality as confounder. The optimal cutoff value of PA for mortality prediction was determined by ROC curve analysis. Using this cutoff value, patients were categorized into low or normal PA group and the association with 90-day mortality was tested again. The PA of survivors was higher than of the non-survivors (5.0° ± 1.3° vs. 4.1° ± 1.2°, p < 0.001). The area under the ROC curve of PA for 90-day mortality was 0.70 (CI 0.59-0.80). PA was associated with 90-day mortality (OR = 0.56, CI: 0.38-0.77, p = 0.001) on univariate logistic regression analysis and also after adjusting for BMI, gender, age, and APACHE IV on multivariable logistic regression (OR = 0.65, CI: 0.44-0.96, p = 0.031). A PA < 4.8° was an independent predictor of 90-day mortality (adjusted OR = 3.65, CI: 1.34-9.93, p = 0.011). Phase angle at ICU admission is an independent predictor of 90-day mortality. This biological marker can aid in long-term mortality risk assessment of critically ill patients.

  10. Comparison of two bioelectrical impedance devices and dual-energy X-ray absorptiometry to evaluate body composition in heart failure.

    PubMed

    Alves, F D; Souza, G C; Biolo, A; Clausell, N

    2014-12-01

    The utilisation of bioelectrical impedance analysis (BIA) in heart failure can be affected by many factors and its applicability remains controversial. The present study aimed to verify the adequacy of single-frequency BIA (SF-BIA) and multifrequency BIA (MF-BIA) compared to dual-energy x-ray absorptiometry (DEXA) for evaluating body composition in outpatients with heart failure. In this cross-sectional study, 55 patients with stable heart failure and left ventricle ejection fraction ≤45% were evaluated for fat mass percentage, fat mass and fat-free mass by DEXA and compared with the results obtained by SF-BIA (single frequency of 50 kHz) and MF-BIA (frequencies of 20 and 100 kHz). MF-BIA and DEXA gave similar mean values for fat mass percentage, fat mass and fat-free mass, whereas values from SF-BIA were significantly different from DEXA. Both SF-BIA and MF-BIA measures of body composition correlated strongly with DEXA (r > 0.8; P < 0.001), except for fat mass assessed by SF-BIA, which showed a moderate correlation (r = 0.760; P < 0.001). MF-BIA also showed a better agreement with DEXA by Bland-Altman analysis in all measurements. However, both types of equipment showed wide limits of agreement and a significant relationship between variance and bias (Pitmans's test P > 0.05), except MF-BIA for fat-free mass. Compared with DEXA, MF-BIA showed better accuracy than SF-BIA, although both types of equipment showed wide limits of agreement. The BIA technique should be used with caution, and regression equations might be useful for correcting the observed variations, mainly in extreme values of body composition. © 2014 The British Dietetic Association Ltd.

  11. The investigation of the some body parameters of obese and (obese+diabetes) patients with using bioelectrical impedance analysis techniques

    NASA Astrophysics Data System (ADS)

    Yerlikaya, Emrah; Karageçili, Hasan; Aydin, Ruken Zeynep

    2016-04-01

    Obesity is a key risk for the development of hyperglycemia, hypertension, hyperlipidemia, insulin resistance and is totally referred to as the metabolic disorders. Diabetes mellitus, a metabolic disorder, is related with hyperglycemia, altered metabolism of lipids, carbohydrates and proteins. The minimum defining characteristic feature to identify diabetes mellitus is chronic and substantiated elevation of circulating glucose concentration. In this study, it is aimed to determine the body composition analyze of obese and (obese+diabetes) patients.We studied the datas taken from three independent groups with the body composition analyzer instrument. The body composition analyzer calculates body parameters, such as body fat ratio, body fat mass, fat free mass, estimated muscle mass, and base metabolic rate on the basis of data obtained by Dual Energy X-ray Absorptiometry using Bioelectrical Impedance Analysis. All patients and healthy subjects applied to Siirt University Medico and their datas were taken. The Statistical Package for Social Sciences version 21 was used for descriptive data analysis. When we compared and analyzed three groups datas, we found statistically significant difference between obese, (obese+diabetes) and control groups values. Anova test and tukey test are used to analyze the difference between groups and to do multiple comparisons. T test is also used to analyze the difference between genders. We observed the statistically significant difference in age and mineral amount p<0.00 between (diabetes+obese) and obese groups. Besides, when these patient groups and control group were analyzed, there were significant difference between most parameters. In terms of education level among the illiterate and university graduates; fat mass kg, fat percentage, internal lubrication, body mass index, water percentage, protein mass percentage, mineral percentage p<0.05, significant statistically difference were observed. This difference especially may result

  12. Single cross-sectional area of pectoralis muscle by computed tomography - correlation with bioelectrical impedance based skeletal muscle mass in healthy subjects.

    PubMed

    Kim, Young Saing; Kim, Eun Young; Kang, Shin Myung; Ahn, Hee Kyung; Kim, Hyung Sik

    2017-09-01

    Skeletal muscle depletion is an important prognostic factor in patients with chronic obstructive pulmonary disease (COPD); a recent study demonstrated significant correlations between pectoralis muscle area on an axial CT image and COPD-related traits. The purpose of this study was to evaluate the relation between pectoralis muscle areas on CT scans and total body skeletal muscle mass (SMM) in healthy subjects. For 434 subjects that underwent a low-dose chest CT and bioelectrical impedance analysis (BIA) during health screening from January to June of 2014, cross-sectional area of pectoralis muscles were measured in CT scans. Pearson's correlation and multiple linear regression analysis were used to assess the relationship between cross-sectional CT areas of pectoralis muscles and BIA-assessed SMMs. Mean age was 50 ± 10 years (78·8% were male). The mean cross-sectional area of pectoralis muscles was 24·1 cm 2  ± 6·8. A moderate correlation was observed between pectoralis muscle area and BIA-based SMM (r = 0·665, P<0.001). Multivariable analysis showed CT determined pectoralis muscle area was significantly associated with BIA-assessed SMM after adjusting for gender, weight, height and age (β = 0·14 ± 0·02, P<0·001). Cross-sectional area of the pectoralis muscles on single axial CT images shows moderate correlation with total body SMM determined by BIA in healthy subjects. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  13. The additional value of bioelectrical impedance analysis-derived muscle mass as a screening tool in geriatric assessment for fall prevention.

    PubMed

    Van Puyenbroeck, Karolien; Roelandts, Lieven; Van Deun, Thomas; Van Royen, Paul; Verhoeven, Veronique

    2012-01-01

    The decline in skeletal muscle in old age is a factor in the development of functional limitations. The objective of this study was to assess if there is a correlation between muscle mass based on bioelectrical impedance analysis (BIA) detection and the fall incidence in nursing home residents and to examine the risk factors for falling in nursing home residents. This prospective cohort study was part of a longitudinal study on nutritional issues in 52 nursing homes in Antwerp (Belgium) from October 2007 to April 2008. Two hundred and seventy-six people aged 65 years and older were included. Each subject was assessed with BIA, the timed get-up-and-go test, the Katz score, the Mini Nutritional Assessment - Short Form and the 36-Item Short Form Health Survey. The primary outcome parameter was fall incidence during the study. The prevalence of sarcopenia varied from 24.3 to 81.5% depending on which definition was used. No association was found between BIA-derived muscle mass and fall incidence. Logistic regression analysis showed that gait speed (odds ratio 1.029; p = 0.003) and mental health (odds ratio 0.981; p = 0.015) are significantly associated with fall incidence in nursing homes. A receiver operating characteristic curve showed that none of the BIA-derived muscle parameters are good predictors of the risk of falling. This study shows that there is no association between sarcopenia based on BIA and fall incidence and that BIA-derived muscle mass has no additional value in predicting fall incidents compared to the timed get-up-and-go test. Copyright © 2012 S. Karger AG, Basel.

  14. Assessing Body Composition of Children and Adolescents Using Dual-Energy X-Ray Absorptiometry, Skinfolds, and Electrical Impedance

    ERIC Educational Resources Information Center

    Mooney, Angela; Kelsey, Laurel; Fellingham, Gilbert W.; George, James D.; Hager, Ron L.; Myrer, J. William; Vehrs, Pat R.

    2011-01-01

    To determine the validity and reliability of percent body fat estimates in 177 boys and 154 girls between 12-17 years of age, percent body fat was assessed once using dual-energy X-ray absorptiometry and twice using the sum of two skinfolds and three bioelectrical impedance analysis devices. The assessments were repeated on 79 participants on a…

  15. Fat-free mass prediction equations for bioelectric impedance analysis compared to dual energy X-ray absorptiometry in obese adolescents: a validation study.

    PubMed

    Hofsteenge, Geesje H; Chinapaw, Mai J M; Weijs, Peter J M

    2015-10-15

    In clinical practice, patient friendly methods to assess body composition in obese adolescents are needed. Therefore, the bioelectrical impedance analysis (BIA) related fat-free mass (FFM) prediction equations (FFM-BIA) were evaluated in obese adolescents (age 11-18 years) compared to FFM measured by dual-energy x-ray absorptiometry (FFM-DXA) and a new population specific FFM-BIA equation is developed. After an overnight fast, the subjects attended the outpatient clinic. After measuring height and weight, a full body scan by dual-energy x-ray absorptiometry (DXA) and a BIA measurement was performed. Thirteen predictive FFM-BIA equations based on weight, height, age, resistance, reactance and/or impedance were systematically selected and compared to FFM-DXA. Accuracy of FFM-BIA equations was evaluated by the percentage adolescents predicted within 5% of FFM-DXA measured, the mean percentage difference between predicted and measured values (bias) and the Root Mean Squared prediction Error (RMSE). Multiple linear regression was conducted to develop a new BIA equation. Validation was based on 103 adolescents (60% girls), age 14.5 (sd1.7) years, weight 94.1 (sd15.6) kg and FFM-DXA of 56.1 (sd9.8) kg. The percentage accurate estimations varied between equations from 0 to 68%; bias ranged from -29.3 to +36.3% and RMSE ranged from 2.8 to 12.4 kg. An alternative prediction equation was developed: FFM = 0.527 * H(cm)(2)/Imp + 0.306 * weight - 1.862 (R(2) = 0.92, SEE = 2.85 kg). Percentage accurate prediction was 76%. Compared to DXA, the Gray equation underestimated the FFM with 0.4 kg (55.7 ± 8.3), had an RMSE of 3.2 kg, 63% accurate prediction and the smallest bias of (-0.1%). When split by sex, the Gray equation had the narrowest range in accurate predictions, bias, and RMSE. For the assessment of FFM with BIA, the Gray-FFM equation appears to be the most accurate, but 63% is still not at an acceptable accuracy level for obese adolescents. The new equation appears to

  16. Comparative associations between anthropometric and bioelectric impedance analysis derived adiposity measures with blood pressure and hypertension in India: a cross-sectional analysis.

    PubMed

    Taing, Kevin Y; Farkouh, Michael E; Moineddin, Rahim; Tu, Jack V; Jha, Prabhat

    2017-01-01

    The utility of bioelectrical impedance analysis (BIA) derived adiposity measures as compared to anthropometric measures for the assessment of adiposity-related health risk is not clear. We aimed to clarify the relationships of BIA and anthropometric derived adipose measures with blood pressure and hypertension, and to compare the discriminative ability of the respective measures for hypertension. We used baseline data collected between 2015 and 2016 from the Indian Study on Health of Adults (ISHA), an ongoing population based cohort study in India ( N  = 5990; age 30-69 years). We examined and compared the associations and discriminative ability between anthropometric (body mass index, waist circumference, hip circumference, waist-hip ratio, waist-height ratio) and BIA (whole body and trunk fat percentage) derived adiposity measures with blood pressure components (systolic pressure, diastolic pressure, pulse pressure, mean arterial pressure, mid-blood pressure) and hypertension. Regardless of whether the adiposity measure was derived from BIA or anthropometry, all were strongly and positively associated with blood pressure and hypertension. For both men and women, the magnitude of association of BIA measures with blood pressure and hypertension were comparable to those of anthropometric measures. Further, the ability of BIA derived adiposity measures to distinguish between those with and without hypertension was similar to the discriminative ability of anthropometric measures. As compared to simple anthropometric measures, BIA derived estimates of adiposity provide no apparent advantage in the assessment of blood pressure and hypertension. The observed similarities between adiposity measures suggest that simple anthropometrics may be sufficient to assess adiposity and adiposity-related risks.

  17. Prevalence of malnutrition and validation of bioelectrical impedance analysis for the assessment of body composition in patients with systemic sclerosis.

    PubMed

    Spanjer, Moon J; Bultink, Irene E M; de van der Schueren, Marian A E; Voskuyl, Alexandre E

    2017-06-01

    The aims were to assess the prevalence of malnutrition and to validate bioelectrical impedance analysis (BIA) against whole-body DXA for the assessment of body composition in patients with SSc. Malnutrition was defined as BMI <18.5 kg/m 2 or unintentional weight loss >10% in combination with a fat-free mass index (FFMI) <15 kg/m 2 for women or <17 kg/m 2 for men or BMI <20.0 kg/m 2 (age <70 years) or <22 kg/m 2 (age >70 years). Body composition was assessed in 72 patients with whole-body DXA (Hologic, Discovery A) and BIA (Bodystat Quadscan 400). The manufacturer's equation and the Geneva equation were used to estimate FFM and fat mass. The agreement between BIA and whole-body DXA was assessed with Bland-Altman analysis and intraclass correlation coefficient. Malnutrition was found in 8.3% (n = 6) and low FFMI in 20.8% (n = 15) of patients. The mean difference in FFM between BIA and DXA applying the Geneva equation was 0.02 ( s . d . 2.4) kg, intraclass correlation coefficient 0.97 (95% CI: 0.95, 0.98). Limits of agreement were ±4.6 kg. The manufacturer's equation was less adequate to predict FFM. This study shows a relatively low prevalence of malnutrition in comparison with other studies, but a high prevalence of low FFMI, underlining the necessity of measuring body composition in SSc patients with a standardized and validated method. A good validity of BIA in determining FFM was found at a group level, while at an individual level the FFM may vary by 4.6 kg. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  18. [Comparison BMC assessed by dual-energy X-ray absorptiometry and multi-frequency bioelectrical impedance in Chinese overweight and obesity adults].

    PubMed

    Wang, Zhenghe; Fu, Lianguo; Yang, Yide; Wang, Shuo; Ma, Jun

    2016-05-01

    To compare consistency of Body Mineral Content (BMC, kg) assessed by Multi-frequency Bioelectrical Impedance Analysis ( MF-BIA) and Dual Energy X-ray Absorptiometry (DXA) measurement, providing evidence for MF-BIA accurate application in Chinese overweight/obese adults. A total of 1323 overweight/obesity adults aged 22-55 years were recruited voluntarily. All the subjects received the measurement of BMC both using MF-BIA and DXA. To evaluate the agreement of BMC measured by MF-BIA and DXA using interclass correlation coefficients (ICC), then establish correction prediction models. The mean difference of BMC between two methods was significant different with 0, overweight male subgroup was 0.28 kg, and 0.38 kg for obesity male, 0.24 kg for overweight female and 0.36 kg for obesity female, respectively (P < 0.05). The ICC of BMC between MF-BIA and DXA measurement were statistically significant in all subgroups (P < 0.01). The ICC for overweight male subgroup was 0.787, 0.796 for obesity male, 0.741 for overweight female and 0.788 for obesity female, respectively. Correction prediction model: overweight male population: BMC (DXA method) = -0.297 + 1.005 x BMC (MF-BIA method). Obese male population: BMC (DXA method) =0.302 + 0.799 x BMC (MF-BIA method). Overweight female groups: BMC (DXA method) = 0.780 + 0.598 x BMC (MF-BIA method). Obese female group: BMC (DXA method) = 0.755 + 0.597 x BMC (MF-BIA method). Upon examination, correction prediction models were better. Co The correlation and agreement of BMC measured by BIA and DXA are weak in Chinese overweight/obese adults. Therefore, consideration should be given to BMC measured by BIA method in Chinese overweight/obese adults. It should be corrected or adjusted to reduce errors compared with DXA method.

  19. Bioelectric Signal Measuring System

    NASA Astrophysics Data System (ADS)

    Guadarrama-Santana, A.; Pólo-Parada, L.; García-Valenzuela, A.

    2015-01-01

    We describe a low noise measuring system based on interdigitated electrodes for sensing bioelectrical signals. The system registers differential voltage measurements in order of microvolts. The base noise during measurements was in nanovolts and thus, the sensing signals presented a very good signal to noise ratio. An excitation voltage of 1Vrms with 10 KHz frequency was applied to an interdigitated capacitive sensor without a material under test and to a mirror device simultaneously. The output signals of both devices was then subtracted in order to obtain an initial reference value near cero volts and reduce parasitic capacitances due to the electronics, wiring and system hardware as well. The response of the measuring system was characterized by monitoring temporal bioelectrical signals in real time of biological materials such as embryo chicken heart cells and bovine suprarenal gland cells.

  20. Body composition analysis and adipocytokine concentrations in haemodialysis patients: abdominal fat gain as an additional cardiovascular risk factor.

    PubMed

    González, Elena; Díez, Juan J; Pérez Torres, Almudena; Bajo, María Auxiliadora; Del Peso, Gloria; Sánchez-Villanueva, Rafael; Grande, Cristina; Rodríguez, Olaia; Coronado, Mónica; Gómez Candela, Carmen; Díaz-Almirón, Mariana; Iglesias, Pedro; Selgas, Rafael

    Abdominal fat and its increment over time in particular has become a cardiovascular risk factor in uraemic patients. To analyse changes in abdominal fat in haemodialysis patients over one year and study their possible correlation with the variation in adipocytokine serum levels. As a secondary objective, we tried to validate the data obtained by bioelectrical impedance analysis (BIA) with data obtained by dual X-ray absorptiometry (DXA). A prospective one-year study was performed in 18 patients on haemodialysis (HD). In each patient, body composition by BIA and DXA was estimated at baseline and after one year. Several adipocytokine and biochemical parameters were determined. A significant increase in phase angle [4.8° (4.1-5.6) vs. 5.2° (4.4-5.8), P<.05], BIA intracellular water [48.3% (43.1-52.3) vs. 50.3% (45.7-53.4), P<.05] and the ratio between the percentage of android/gynecoid (A/G) distribution of fat measured by DXA [1.00 (0.80-1.26) vs. 1.02 (0.91-1.30), P<.05] was observed. A statistically significant relationship between leptin and adiponectin concentrations and the percentage of fat mass measured by BIA, as well as the abdominal fat percentage estimated by DXA, was found (P<.01). HD patients exhibit a gain in fat mass over time, especially in the abdomen, evidenced by an increased A/G ratio. These findings might explain the increased cardiovascular risk in these patients. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  1. Phase angle as bioelectrical marker to identify elderly patients at risk of sarcopenia.

    PubMed

    Basile, Claudia; Della-Morte, David; Cacciatore, Francesco; Gargiulo, Gaetano; Galizia, Gianluigi; Roselli, Mario; Curcio, Francesco; Bonaduce, Domenico; Abete, Pasquale

    2014-10-01

    Several markers have been associated with sarcopenia in the elderly, including bioelectrical indices. Phase angle (PhA) is an impedance parameter and it has been suggested as an indicator of cellular death. Thus, the relationship between PhA and muscle mass and strength was investigated in 207 consecutively elderly participants (mean age 76.2±6.7years) admitted for multidimensional geriatric evaluation. Muscle strength by grip strength using a hand-held dynamometer and muscle mass was measured by bioimpedentiometer. PhA was calculated directly with its arctangent (resistance/reactance×180°/π). Linear relationship among muscular mass and strength and with clinical and biochemical parameters, including PhA at uni- and multivariate analysis were performed. Linear regression analysis demonstrated that lower level of PhA is associated with reduction in grip strength (y=3.16+0.08x; r=0.49; p<0.001), and even more, with muscle mass (y=3.04+0.25x; r=0.60; p<0001). Multivariate analysis confirms these relationships (grip strength β=0.245, p=0.031; muscular mass β=0.623, p<0.01). Thus, PhA is inversely related to muscle mass and strength in elderly subjects and it may be considered a good bioelectrical marker to identify elderly patients at risk of sarcopenia. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Exploring Instructive Physiological Signaling with the Bioelectric Tissue Simulation Engine

    PubMed Central

    Pietak, Alexis; Levin, Michael

    2016-01-01

    Bioelectric cell properties have been revealed as powerful targets for modulating stem cell function, regenerative response, developmental patterning, and tumor reprograming. Spatio-temporal distributions of endogenous resting potential, ion flows, and electric fields are influenced not only by the genome and external signals but also by their own intrinsic dynamics. Ion channels and electrical synapses (gap junctions) both determine, and are themselves gated by, cellular resting potential. Thus, the origin and progression of bioelectric patterns in multicellular tissues is complex, which hampers the rational control of voltage distributions for biomedical interventions. To improve understanding of these dynamics and facilitate the development of bioelectric pattern control strategies, we developed the BioElectric Tissue Simulation Engine (BETSE), a finite volume method multiphysics simulator, which predicts bioelectric patterns and their spatio-temporal dynamics by modeling ion channel and gap junction activity and tracking changes to the fundamental property of ion concentration. We validate performance of the simulator by matching experimentally obtained data on membrane permeability, ion concentration and resting potential to simulated values, and by demonstrating the expected outcomes for a range of well-known cases, such as predicting the correct transmembrane voltage changes for perturbation of single cell membrane states and environmental ion concentrations, in addition to the development of realistic transepithelial potentials and bioelectric wounding signals. In silico experiments reveal factors influencing transmembrane potential are significantly different in gap junction-networked cell clusters with tight junctions, and identify non-linear feedback mechanisms capable of generating strong, emergent, cluster-wide resting potential gradients. The BETSE platform will enable a deep understanding of local and long-range bioelectrical dynamics in tissues, and

  3. New reference values for body composition by bioelectrical impedance analysis in the general population: results from the UK Biobank.

    PubMed

    Franssen, Frits M E; Rutten, Erica P A; Groenen, Miriam T J; Vanfleteren, Lowie E; Wouters, Emiel F M; Spruit, Martijn A

    2014-06-01

    Low fat-free mass (FFM) is a risk factor for morbidity and mortality in elderly and patient populations. Therefore, measurement of FFM is important in nutritional assessment. Bioelectrical impedance analysis (BIA) is a convenient method to assess FFM and FFM index (FFMI; FFM/height(2)). Although reference values have been established for individuals with normal body weight, no specific cutoff values are available for overweight and obese populations. Also, limited studies accounted for the age-related decline in FFM. To determine BMI- and age-specific reference values for abnormal low FFM(I) in white-ethnic men and women free of self-reported disease from the general population. The UK Biobank is a prospective epidemiological study of the general population from the United Kingdom. Individuals in the age category 45 to 69 years were analyzed. In addition to body weight, FFM and FFMI were measured using a Tanita BC-418MA. Also, self-reported chronic conditions and ethnic background were registered, and lung function was assessed using spirometry. After exclusion of all individuals with missing data, nonwhite ethnicity, self-reported disease, body mass index (BMI) less than 14 or 36 kg/m(2) or higher, and/or an obstructive lung function, reference values for FFM and FFMI were derived from 186,975 individuals (45.9% men; age: 56.9 ± 6.8 years; BMI: 26.5 ± 3.6 kg/m(2); FFMI 18.3 ± 2.4 kg/m(2)). FFM and FFMI were significantly associated with BMI and decreased with age. Percentiles 5, 10, 25, 50, 75, 90, and 95 were calculated for FFM, FFMI, and fat mass (index), after stratification for gender, age, and BMI. Using the UK Biobank dataset, new reference values for body composition assessed with BIA were determined in white-ethnic men and women aged 45 to 69 years. Because these reference values are BMI specific, they are of broad interest for overweight and obese populations. Copyright © 2014 American Medical Directors Association, Inc. Published by Elsevier Inc. All

  4. Lactate threshold by muscle electrical impedance in professional rowers

    NASA Astrophysics Data System (ADS)

    Jotta, B.; Coutinho, A. B. B.; Pino, A. V.; Souza, M. N.

    2017-04-01

    Lactate threshold (LT) is one of the physiological parameters usually used in rowing sport training prescription because it indicates the transitions from aerobic to anaerobic metabolism. Assessment of LT is classically based on a series of values of blood lactate concentrations obtained during progressive exercise tests and thus has an invasive aspect. The feasibility of noninvasive LT estimative through bioelectrical impedance spectroscopy (BIS) data collected in thigh muscles during rowing ergometer exercise tests was investigated. Nineteen professional rowers, age 19 (mean) ± 4.8 (standard deviation) yr, height 187.3 ± 6.6 cm, body mass 83 ± 7.7 kg, and training experience of 7 ± 4 yr, were evaluated in a rowing ergometer progressive test with paired measures of blood lactate concentration and BIS in thigh muscles. Bioelectrical impedance data were obtained by using a bipolar method of spectroscopy based on the current response to a voltage step. An electrical model was used to interpret BIS data and to derive parameters that were investigated to estimate LT noninvasively. From the serial blood lactate measurements, LT was also determined through Dmax method (LTDmax). The zero crossing of the second derivative of kinetic of the capacitance electrode (Ce), one of the BIS parameters, was used to estimate LT. The agreement between the LT estimates through BIS (LTBIS) and through Dmax method (LTDmax) was evaluated using Bland-Altman plots, leading to a mean difference between the estimates of just 0.07 W and a Pearson correlation coefficient r = 0.85. This result supports the utilization of the proposed method based on BIS parameters for estimating noninvasively the lactate threshold in rowing.

  5. Preoperative and postoperative agreement in fat free mass (FFM) between bioelectrical impedance spectroscopy (BIS) and dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery.

    PubMed

    van Venrooij, Lenny M W; Verberne, Hein J; de Vos, Rien; Borgmeijer-Hoelen, Mieke M M J; van Leeuwen, Paul A M; de Mol, Bas A J M

    2010-12-01

    To measure undernutrition in terms of fat free mass (FFM), there are several options. The aim of this study was to assess agreement in FFM between the portable, bedside bioelectrical impedance spectrometry (BIS) and relatively expensive, non-portable dual-energy X-ray absorptiometry (DXA) in patients undergoing cardiac surgery. In a prospective study, body composition measurements by BIS and DXA were performed two weeks prior and two months after cardiac surgery. Preoperative and postoperative agreement in FFM between BIS and DXA were analyzed with Bland and Altman plots. Twenty-six patients were analyzed. BIS overestimated preoperative and postoperative FFM by 2 kg compared to DXA (2.3 kg (95%CI: -3.5-8.1 kg) and 2.1 kg (95%CI: -4.5-8.7 kg), respectively). BIS underestimated FFM change by -0.5% (95%CI: -8.4-7.5%). There is a large inter-individual variation between BIS and DXA. This hinders the interchange-ability of BIS and DXA in routine clinical practice and may lead to misclassifications and thereby inappropriate nutritional treatment and possible postoperative complications. To evaluate nutritional therapy in patients undergoing cardiac surgery, we advocate the use of DXA assessed FFM in parallel to BIS assessed extracellular and intracellular water and FFM. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  6. Validity of bioelectrical impedance analysis in estimation of fat-free mass in colorectal cancer patients.

    PubMed

    Ræder, Hanna; Kværner, Ane Sørlie; Henriksen, Christine; Florholmen, Geir; Henriksen, Hege Berg; Bøhn, Siv Kjølsrud; Paur, Ingvild; Smeland, Sigbjørn; Blomhoff, Rune

    2018-02-01

    Bioelectrical impedance analysis (BIA) is an accessible and cheap method to measure fat-free mass (FFM). However, BIA estimates are subject to uncertainty in patient populations with altered body composition and hydration. The aim of the current study was to validate a whole-body and a segmental BIA device against dual-energy X-ray absorptiometry (DXA) in colorectal cancer (CRC) patients, and to investigate the ability of different empiric equations for BIA to predict DXA FFM (FFM DXA ). Forty-three non-metastatic CRC patients (aged 50-80 years) were enrolled in this study. Whole-body and segmental BIA FFM estimates (FFM whole-bodyBIA , FFM segmentalBIA ) were calculated using 14 empiric equations, including the equations from the manufacturers, before comparison to FFM DXA estimates. Strong linear relationships were observed between FFM BIA and FFM DXA estimates for all equations (R 2  = 0.94-0.98 for both devices). However, there were large discrepancies in FFM estimates depending on the equations used with mean differences in the ranges -6.5-6.8 kg and -11.0-3.4 kg for whole-body and segmental BIA, respectively. For whole-body BIA, 77% of BIA derived FFM estimates were significantly different from FFM DXA , whereas for segmental BIA, 85% were significantly different. For whole-body BIA, the Schols* equation gave the highest agreement with FFM DXA with mean difference ±SD of -0.16 ± 1.94 kg (p = 0.582). The manufacturer's equation gave a small overestimation of FFM with 1.46 ± 2.16 kg (p < 0.001) with a tendency towards proportional bias (r = 0.28, p = 0.066). For segmental BIA, the Heitmann* equation gave the highest agreement with FFM DXA (0.17 ± 1.83 kg (p = 0.546)). Using the manufacturer's equation, no difference in FFM estimates was observed (-0.34 ± 2.06 kg (p = 0.292)), however, a clear proportional bias was detected (r = 0.69, p < 0.001). Both devices demonstrated acceptable ability to detect low FFM compared to

  7. The Performance of Five Bioelectrical Impedance Analysis Prediction Equations against Dual X-ray Absorptiometry in Estimating Appendicular Skeletal Muscle Mass in an Adult Australian Population

    PubMed Central

    Yu, Solomon C. Y.; Powell, Alice; Khow, Kareeann S. F.; Visvanathan, Renuka

    2016-01-01

    Appendicular skeletal muscle mass (ASM) is a diagnostic criterion for sarcopenia. Bioelectrical impedance analysis (BIA) offers a bedside approach to measure ASM but the performance of BIA prediction equations (PE) varies with ethnicities and body composition. We aim to validate the performance of five PEs in estimating ASM against estimation by dual-energy X-ray absorptiometry (DXA). We recruited 195 healthy adult Australians and ASM was measured using single-frequency BIA. Bland-Altman analysis was used to assess the predictive accuracy of ASM as determined by BIA against DXA. Precision (root mean square error (RMSE)) and bias (mean error (ME)) were calculated according to the method of Sheiner and Beal. Four PEs (except that by Kim) showed ASM values that correlated strongly with ASMDXA (r ranging from 0.96 to 0.97, p < 0.001). The Sergi equation performed the best with the lowest ME of −1.09 kg (CI: −0.84–−1.34, p < 0.001) and the RMSE was 2.09 kg (CI: 1.72–2.47). In men, the Kyle equation performed better with the lowest ME (−0.32 kg (CI: −0.66–0.02) and RMSE (1.54 kg (CI: 1.14–1.93)). The Sergi equation is applicable in adult Australians (Caucasian) whereas the Kyle equation can be considered in males. The need remains to validate PEs in other ethnicities and to develop equations suitable for multi-frequency BIA. PMID:27043617

  8. Aerophagia: excessive air swallowing demonstrated by esophageal impedance monitoring.

    PubMed

    Hemmink, Gerrit J M; Weusten, Bas L A M; Bredenoord, Albert J; Timmer, Robin; Smout, André J P M

    2009-10-01

    Patients with aerophagia suffer from the presence of an excessive volume of intestinal gas, which is thought to result from excessive air ingestion. However, this has not been shown thus far. The aim of this study was therefore to assess swallowing and air swallowing frequencies in patients with suspected aerophagia. Ambulatory 24-hour pH-impedance monitoring was performed in patients in whom excessive amounts of intestinal gas were visualized on plain abdominal radiograms. All patients had symptoms of bloating, abdominal distention, flatulence, or excessive belching. Reflux parameters and the number of swallows and air swallows were assessed. The most common symptoms were bloating, abdominal distention, and constipation. Only 3 patients reported excessive belching and 1 patient reported flatulence as their predominant symptom. During the 24-hour measurement, patients showed high incidences of air swallows (521 +/- 63) and gastric belches (126 +/- 37). Patients had normal swallowing frequency (741 +/- 71). This study presents objective parameters that confirm the existence of excessive air swallowing or aerophagia using esophageal impedance monitoring.

  9. Laplacian Electrode to Record Small Bowel Myoelectrical Activity From Abdominal Surface

    DTIC Science & Technology

    2001-10-25

    de Bioelectronica Departamento de Ingenieria Electronica Universidad Politecnica de Valencia. Spain Performing Organization Report Number Sponsoring...and by a grant from the Fondo de Investigaciones Sanitarias del Instituto Carlos III (FIS-00/1039)(Spain). -1 -0,5 0 0,5 1 0 5 10 15 20 time (s) e le...ABDOMINAL SURFACE G. Prats-Boluda1, J.L. Martínez1, J. Silvestre2, F.J. Sáiz, J.L Ponce2,3, J. García-Casado1 1Grupo de Bioelectrónica. Departamento de

  10. Agreement between bioelectrical impedance and dual energy X-ray absorptiometry in assessing fat, lean and bone mass changes in adults after a lifestyle intervention.

    PubMed

    Macfarlane, Duncan J; Chan, Natalie T-Y; Tse, Michael A; Joe, Glen M

    2016-01-01

    We aimed to assess the agreement of a commercially available bioelectrical impedance analysis (BIA) device in measuring changes in fat, lean and bone mass over a 10-week lifestyle intervention, with dual energy X-ray absorptiometry (DXA) as reference. A sample of 136 volunteers (18-66 years) underwent a physical activity intervention to enhance lean mass and reduce fat mass. BIA (Tanita BC545) and DXA (Hologic Explorer) measures of whole-body composition were taken at baseline and at the end of the intervention. After an average of 74 ± 18 days intervention, DXA showed significant changes in 2 of 3 outcome variables: reduced fat mass of 0.802 ± 1.092 kg (P < 0.001), increased lean mass of 0.477 ± 0.966 kg (P < 0.001); minor non-significant increase of 0.007 ± 0.041 kg of bone mass (P = 0.052). The respective changes in BIA measures were a significant reduction of 0.486 ± 1.539 kg fat (P < 0.001), but non-significant increases of 0.084 ± 1.201 kg lean mass (P = 0.425), and 0.014 ± 0.091 kg bone (P = 0.074). Significant, but moderately weak, correlations were seen in absolute mass changes between DXA and BIA: 0.511 (fat), 0.362 (lean) and 0.172 (bone). Compared to DXA, BIA demonstrated mediocre agreement to changes in fat mass, but poor agreement to lean mass changes. BIA significantly underestimated the magnitude of changes in fat and lean mass compared to DXA.

  11. Performance of Two Bioelectrical Impedance Analyses in the Diagnosis of Overweight and Obesity in Children and Adolescents: The FUPRECOL Study

    PubMed Central

    Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; Martínez-Torres, Javier; González-Ruíz, Katherine; González-Jiménez, Emilio; Schmidt-RioValle, Jacqueline; Garcia-Hermoso, Antonio

    2016-01-01

    This study aimed to determine thresholds for percentage of body fat (BF%) corresponding to the cut-off values for overweight/obesity as recommended by the International Obesity Task Force (IOTF), using two bioelectrical impedance analyzers (BIA), and described the likelihood of increased cardiometabolic risk in our cohort defined by the IOTF and BF% status. Participants included 1165 children and adolescents (54.9% girls) from Bogotá (Colombia). Body mass index (BMI) was calculated from height and weight. BF% of each youth was assessed first using the Tanita BC-418® followed by a Tanita BF-689®. The sensitivity and specificity of both devices and their ability to correctly classify children as overweight/obesity (≥2 standard deviation), as defined by IOTF, was investigated using receiver operating characteristic (ROC) by sex and age groups (9–11, 12–14, and 13–17 years old); Area under curve (AUC) values were also reported. For girls, the optimal BF% threshold for classifying into overweight/obesity was found to be between 25.2 and 28.5 (AUC = 0.91–0.97) and 23.9 to 26.6 (AUC = 0.90–0.99) for Tanita BC-418® and Tanita BF-689®, respectively. For boys, the optimal threshold was between 16.5 and 21.1 (AUC = 0.93–0.96) and 15.8 to 20.6 (AUC = 0.92–0.94) by Tanita BC-418® and Tanita BF-689®, respectively. All AUC values for ROC curves were statistically significant and there were no differences between AUC values measured by both BIA devices. The BF% values associated with the IOTF-recommended BMI cut-off for overweight/obesity may require age- and sex-specific threshold values in Colombian children and adolescents aged 9–17 years and could be used as a surrogate method to identify individuals at risk of excess adiposity. PMID:27782039

  12. Performance of Two Bioelectrical Impedance Analyses in the Diagnosis of Overweight and Obesity in Children and Adolescents: The FUPRECOL Study.

    PubMed

    Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; Martínez-Torres, Javier; González-Ruíz, Katherine; González-Jiménez, Emilio; Schmidt-RioValle, Jacqueline; Garcia-Hermoso, Antonio

    2016-10-04

    This study aimed to determine thresholds for percentage of body fat (BF%) corresponding to the cut-off values for overweight/obesity as recommended by the International Obesity Task Force (IOTF), using two bioelectrical impedance analyzers (BIA), and described the likelihood of increased cardiometabolic risk in our cohort defined by the IOTF and BF% status. Participants included 1165 children and adolescents (54.9% girls) from Bogotá (Colombia). Body mass index (BMI) was calculated from height and weight. BF% of each youth was assessed first using the Tanita BC-418® followed by a Tanita BF-689®. The sensitivity and specificity of both devices and their ability to correctly classify children as overweight/obesity (≥2 standard deviation), as defined by IOTF, was investigated using receiver operating characteristic (ROC) by sex and age groups (9-11, 12-14, and 13-17 years old); Area under curve (AUC) values were also reported. For girls, the optimal BF% threshold for classifying into overweight/obesity was found to be between 25.2 and 28.5 (AUC = 0.91-0.97) and 23.9 to 26.6 (AUC = 0.90-0.99) for Tanita BC-418® and Tanita BF-689®, respectively. For boys, the optimal threshold was between 16.5 and 21.1 (AUC = 0.93-0.96) and 15.8 to 20.6 (AUC = 0.92-0.94) by Tanita BC-418® and Tanita BF-689®, respectively. All AUC values for ROC curves were statistically significant and there were no differences between AUC values measured by both BIA devices. The BF% values associated with the IOTF-recommended BMI cut-off for overweight/obesity may require age- and sex-specific threshold values in Colombian children and adolescents aged 9-17 years and could be used as a surrogate method to identify individuals at risk of excess adiposity.

  13. Comparison of two bioelectrical impedance analysis devices with dual energy X-ray absorptiometry and magnetic resonance imaging in the estimation of body composition.

    PubMed

    Wang, Ji-Guang; Zhang, Yi; Chen, Han-E; Li, Yan; Cheng, Xiao-Guang; Xu, Li; Guo, Zhe; Zhao, Xing-Shan; Sato, Tetsuya; Cao, Qi-Yun; Chen, Ke-Min; Li, Biao

    2013-01-01

    We compared a 4-limb bioelectrical impedance analysis (BIA) system, HBF 359 (Omron), and a 2-limb foot-to-foot device, BC 532 (Tanita), with the standard dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) methods for the measurement of body fat percentage (BF), skeletal muscle mass percentage (SMM, or fat-free mass [FFM] for BC 532), and visceral fat level (VF). Body composition was measured in 200 healthy volunteers (100 men and 100 women, mean age 48 years) by HBF 359 and BC 532 and by DXA and MRI. The agreement was assessed by correlation analysis and paired t-test. The correlation coefficients between BIA and DXA or MRI ranged from 0.71 to 0.89 for BF, SMM, and VF by HBF 359 and from 0.77 to 0.90 for BF, FFM, and VF by BC 532 in all subjects and in men and women separately (p < 0.001 for all). Compared with DXA, HBF 359 significantly (p < 0.001) underestimated BF by -5.8% in men and -9.6% in women. Compared with MRI, the corresponding underestimatons (negative) or overestimations (positive) by HBF 359 in men and women were, respectively, +1.9% (p = 0.02) and +1.7% (p = 0.10) for SMM, and +13.3% (p < 0.001) and -8.5% (p = 0.006), for VF. The corresponding values by BC 532 in men and women were -10.7 and -6.2% for BF, -1.4 and -2.5% for FFM, and +20.4 and -18.0% for VF. The BIA devices are accurate in the estimation of body composition, especially skeletal muscle mass or FFM.

  14. Quantitative analysis of skeletal muscle mass in patients with rheumatic diseases under glucocorticoid therapy--comparison among bioelectrical impedance analysis, computed tomography, and magnetic resonance imaging.

    PubMed

    Hosono, Osamu; Yoshikawa, Noritada; Shimizu, Noriaki; Kiryu, Shigeru; Uehara, Masaaki; Kobayashi, Hiroshi; Matsumiya, Ryo; Kuribara, Akiko; Maruyama, Takako; Tanaka, Hirotoshi

    2015-03-01

    To determine the availability of bioelectrical impedance analysis (BIA), computed tomography (CT), and magnetic resonance imaging (MRI) for measurement of skeletal muscle mass in patients with rheumatic diseases and quantitatively assess skeletal muscle loss after glucocorticoid (GC) treatment. The data from 22 patients with rheumatic diseases were retrospectively obtained. The muscle mass of body segments was measured with a BIA device in terms of skeletal muscle mass index (SMI). Cross-sectional area (CSA) was obtained from CT and MRI scans at the mid-thigh level using the image analysis program. We further assessed the data of three different measurements before and after GC treatment in 7 patients with rheumatic diseases. SMI of whole body was significantly correlated with estimated muscle volume and mid-thigh muscle CSA with CT and MRI (p < 0.01). Significant correlations between SMI and mid-thigh muscle CSA of each leg were also found (p < 0.01). All the three measurements were negatively correlated with GC dosage (p < 0.01). Significant decline in mid-thigh muscle CSA with CT and MRI was found after GC treatment in 7 patients (p < 0.02). Those patients showed significant decline in SMI of whole body after GC treatment, but not in SMI of each leg. On the other hand, significant correlations between mid-thigh muscle CSA with CT and MRI were found before and after GC treatment (p < 0.01). GC-related skeletal muscle loss could be quantitatively assessed with BIA, CT, or MRI in patients with rheumatic diseases, and CT and MRI appeared to be more accurate than BIA.

  15. Some features of the bioelectric activity of the muscles with prolonged hypokinesia

    NASA Technical Reports Server (NTRS)

    Belaya, N. A.; Amirov, R. Z.; Shaposhnikov, Y. A.; Lebedeva, I. P.; Sologub, B. S.

    1978-01-01

    The effects of prolonged hypokinesia, brought on by confinement to bed and the attendant lack of motor activity, on the bioelectric activity of muscles are studied. Electromyographic measurements of amplitude and frequency indicators of muscular bioelectric activity were analyzed.

  16. Interfacing with the nervous system: a review of current bioelectric technologies.

    PubMed

    Sahyouni, Ronald; Mahmoodi, Amin; Chen, Jefferson W; Chang, David T; Moshtaghi, Omid; Djalilian, Hamid R; Lin, Harrison W

    2017-10-23

    The aim of this study is to discuss the state of the art with regard to established or promising bioelectric therapies meant to alter or control neurologic function. We present recent reports on bioelectric technologies that interface with the nervous system at three potential sites-(1) the end organ, (2) the peripheral nervous system, and (3) the central nervous system-while exploring practical and clinical considerations. A literature search was executed on PubMed, IEEE, and Web of Science databases. A review of the current literature was conducted to examine functional and histomorphological effects of neuroprosthetic interfaces with a focus on end-organ, peripheral, and central nervous system interfaces. Innovations in bioelectric technologies are providing increasing selectivity in stimulating distinct nerve fiber populations in order to activate discrete muscles. Significant advances in electrode array design focus on increasing selectivity, stability, and functionality of implantable neuroprosthetics. The application of neuroprosthetics to paretic nerves or even directly stimulating or recording from the central nervous system holds great potential in advancing the field of nerve and tissue bioelectric engineering and contributing to clinical care. Although current physiotherapeutic and surgical treatments seek to restore function, structure, or comfort, they bear significant limitations in enabling cosmetic or functional recovery. Instead, the introduction of bioelectric technology may play a role in the restoration of function in patients with neurologic deficits.

  17. Validation of multi-frequency bioelectrical impedance analysis versus dual-energy X-ray absorptiometry to measure body fat percentage in overweight/obese Colombian adults.

    PubMed

    Ramírez-Vélez, Robinson; Tordecilla-Sanders, Alejandra; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; González-Jiménez, Emilio; Triana-Reina, Hector Reynaldo; García-Hermoso, Antonio; Schmidt-RioValle, Jacqueline

    2018-01-01

    To verify the validity of multi-frequency bioelectrical impedance analysis (mBCA) for predicting body fat percentage (BF%) in overweight/obese adults using dual-energy X-ray absorptiometry (DXA) as the reference method. Forty-eight adults participated (54% women, mean age = 41.0 ± 7.3 years old). The Pearson's correlation coefficient was used to evaluate the correlation between BIA and BF% assessed by DXA. The concordance between BF% measured by both methods was obtained with Lin's concordance correlation coefficient and Bland-Altman difference plots. Measures of BF% were estimated as 39.0 (SD = 6.1) and 38.3 (SD = 6.5) using DXA and mBCA, respectively. The Pearson's correlation coefficient reflected a strong correlation (r =.921, P = .001). The paired t-test showed a significant mean difference between these methods for obese men BF% of -0.6 [(SD 1.95; 95% CI = -4.0 to 3.0), P =.037]. Overall, the bias of the mBCA was -0.6 [(SD 2.2; 95% CI = -5.0 to 3.7), P =.041], which indicated that the mBCA method significantly underestimated BF% in comparison to the reference method. Finally, in both genders, Lin's concordance correlation coefficient showed a strong agreement. More specifically the DXA value was ρc = 0.943 (95% CI = 0.775 to 0.950) and the mBCA value was ρc = 0.948 (95% CI = 0.778 to 0.978). Our analysis showed a strong agreement between the two methods as reflected in the range of BF%. These results show that mBCA and DXA are comparable methods for measuring body composition with higher body fat percentages. However, due to broad limits of agreement, we can only recommend mBCA for groups of populations. © 2017 Wiley Periodicals, Inc.

  18. Endogenous Bioelectric Signaling Networks: Exploiting Voltage Gradients for Control of Growth and Form.

    PubMed

    Levin, Michael; Pezzulo, Giovanni; Finkelstein, Joshua M

    2017-06-21

    Living systems exhibit remarkable abilities to self-assemble, regenerate, and remodel complex shapes. How cellular networks construct and repair specific anatomical outcomes is an open question at the heart of the next-generation science of bioengineering. Developmental bioelectricity is an exciting emerging discipline that exploits endogenous bioelectric signaling among many cell types to regulate pattern formation. We provide a brief overview of this field, review recent data in which bioelectricity is used to control patterning in a range of model systems, and describe the molecular tools being used to probe the role of bioelectrics in the dynamic control of complex anatomy. We suggest that quantitative strategies recently developed to infer semantic content and information processing from ionic activity in the brain might provide important clues to cracking the bioelectric code. Gaining control of the mechanisms by which large-scale shape is regulated in vivo will drive transformative advances in bioengineering, regenerative medicine, and synthetic morphology, and could be used to therapeutically address birth defects, traumatic injury, and cancer.

  19. Airway mucosal bioelectric potential difference in cystic fibrosis after lung transplantation.

    PubMed

    Wood, A; Higenbottam, T; Jackson, M; Scott, J; Stewart, S; Wallwork, J

    1989-12-01

    Bioelectrical potential difference (PD) across the respiratory mucosa is raised in cystic fibrosis (CF). We have recorded airway potentials from seven patients with CF who had undergone heart-lung transplantation and from eight patients without CF who had had transplants for cardiovascular disease; comparison of these populations controls for the effects of denervation and immunosuppressive treatment. Six patients without CF who had not had transplants formed an additional control. PD was recorded during routine fiberoptic bronchoscopy, using a Ringer's-perfused exploring bridge connected across a high impedance amplifier to an intravenous reference bridge. Bronchial lavage and sputum culture revealed no evidence of infection. Bronchial PD was similar in all three groups of patients at equivalent sites. However, nasal PD was raised in the CF group (mean value, 44 mV +/- 3.9 SE) compared with the patients who had transplants for cardiovascular disease (mean, 18 mV +/- 1.1 SE), and the control patients (mean, 15 mV +/- 1.2 SE). We conclude that the epithelial defects that result in raised airway potentials in CF do not recur in the transplanted lung.

  20. Development of bioelectrical impedance-derived indices of fat and fat-free mass for assessment of nutritional status in childhood.

    PubMed

    Wright, C M; Sherriff, A; Ward, S C G; McColl, J H; Reilly, J J; Ness, A R

    2008-02-01

    (1) To develop a method of manipulating bioelectrical impedance (BIA) that gives indices of lean and fat adjusted for body size, using a large normative cohort of children. (2) To assess the discriminant validity of the method in a group of children likely to have abnormal body composition. Two prospective cohort studies. Normative data: Avon Longitudinal Study of Parents and Children (ALSPAC), population based cohort; proof of concept study: tertiary feeding clinic and special needs schools. Normative data: 7576 children measured aged between 7.25 and 8.25 (mean 7.5) (s.d.=0.2) years; proof of concept study: 29 children with either major neurodisability or receiving artificial feeding, or both, mean age 7.6 (s.d.=2) years. Leg-to-leg (Z (T)) and arm-to-leg (Z (B)) BIA, weight and height. Total body water (TBW) was estimated from the resistance index (RI=height(2)/Z), and fat-free mass was linearly related to TBW. Fat mass was obtained by subtracting fat-free mass from total weight. Fat-free mass was log-transformed and the reciprocal transform was taken for fat mass to satisfy parametric model assumptions. Lean and fat mass were then adjusted for height and age using multiple linear regression models. The resulting standardized residuals gave the lean index and fat index, respectively. In the normative cohort, the lean index was higher and fat index lower in boys. The lean index rose steeply to the middle of the normal range of body mass index (BMI) and then slowly for higher BMI values, whereas the fat index rose linearly through and above the normal range. In the proof of concept study, the children as a group had low lean indices (mean (s.d.) -1.5 (1.7)) with average fat indices (+0.21 (2.0)) despite relatively low BMI standard deviation scores (-0.60 (2.3)), but for any given BMI, individual children had extremely wide ranges of fat indices. The lean index proved more stable and repeatable than BMI. This clinical method of handling BIA reveals important

  1. Ethanol or bioelectricity? Life cycle assessment of lignocellulosic bioenergy use in light-duty vehicles.

    PubMed

    Luk, Jason M; Pourbafrani, Mohammad; Saville, Bradley A; MacLean, Heather L

    2013-09-17

    Our study evaluates life cycle energy use and GHG emissions of lignocellulosic ethanol and bioelectricity use in U.S. light-duty vehicles. The well-to-pump, pump-to-wheel, and vehicle cycle stages are modeled. All ethanol (E85) and bioelectricity pathways have similar life cycle fossil energy use (~ 100 MJ/100 vehicle kilometers traveled (VKT)) and net GHG emissions (~5 kg CO2eq./100 VKT), considerably lower (65-85%) than those of reference gasoline and U.S. grid-electricity pathways. E85 use in a hybrid vehicle and bioelectricity use in a fully electric vehicle also have similar life cycle biomass and total energy use (~ 350 and ~450 MJ/100 VKT, respectively); differences in well-to-pump and pump-to-wheel efficiencies can largely offset each other. Our energy use and net GHG emissions results contrast with findings in literature, which report better performance on these metrics for bioelectricity compared to ethanol. The primary source of differences in the studies is related to our development of pathways with comparable vehicle characteristics. Ethanol or vehicle electrification can reduce petroleum use, while bioelectricity may displace nonpetroleum energy sources. Regional characteristics may create conditions under which either ethanol or bioelectricity may be the superior option; however, neither has a clear advantage in terms of GHG emissions or energy use.

  2. Body composition in male elite athletes, comparison of bioelectrical impedance spectroscopy with dual energy X-ray absorptiometry

    PubMed Central

    Svantesson, Ulla; Zander, Martina; Klingberg, Sofia; Slinde, Frode

    2008-01-01

    Background The aim of this study was to compare body composition results from bioelectrical spectroscopy (BIS) with results from dual energy X-ray absorptiometry (DXA) in a population of male elite athletes. Body composition was assessed using DXA (Lunar Prodigy, GE Lunar Corp., Madison, USA) and BIS (Hydra 4200, Xitron Technologies Inc, San Diego, California, USA) at the same occasion. Agreement between methods was assessed using paired t-tests and agreement-plots. Results Thirty-three male elite athletes (soccer and ice hockey) were included in the study. The results showed that BIS underestimates the proportion of fat mass by 4.6% points in the ice hockey players. In soccer players the BIS resulted in a lower mean fat mass by 1.1% points. Agreement between the methods at the individual level was highly variable. Conclusion Body composition results assessed by BIS in elite athletes should be interpreted with caution, especially in individual subjects. BIS may present values of fat mass that is either higher or lower than fat mass assessed by DXA, independent of true fat content of the individual. PMID:18211680

  3. Bioelectricity from kitchen and bamboo waste in a microbial fuel cell.

    PubMed

    Moqsud, M Azizul; Omine, Kiyoshi; Yasufuku, Noriyuki; Bushra, Quazi S; Hyodo, Masayuki; Nakata, Yukio

    2014-02-01

    This study evaluated bioelectricity generation by using kitchen garbage (KG) and bamboo waste (BW) as a solid waste management option by a microbial fuel cell (MFC) method. The nutrient content [nitrogen, phosphorus and potassium (NPK)] of the by-products of bioelectricity were also analyzed and assessed for their potential use as a soil amendment. A one-chamber MFC was used for bioelectricity generation in laboratory experiments using both KG and BW. A data-logger recorded voltage every 20 mins at a constant room temperature of 25°C over 45 days. The trend of voltage generation was different for the two organic wastes. In the case of KG, the voltage at the initial stage (0-5 days) increased rapidly and then gradually to a peak of 620 mV. In contrast, the voltage increased gradually to a peak of 540 mV in the case of BW. The by-products of bioelectricity can be used as soil conditioner as its NPK content was in the range of soil conditioner mentioned in other literature. Thus, the MFC has emerged as an efficient and eco-friendly solution for organic waste management, especially in developing and technologically less sophisticated countries, and can provide green and safe electricity from organic waste.

  4. Bioelectric Control of a 757 Class High Fidelity Aircraft Simulation

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles; Wheeler, Kevin; Stepniewski, Slawomir; Norvig, Peter (Technical Monitor)

    2000-01-01

    This paper presents results of a recent experiment in fine grain Electromyographic (EMG) signal recognition, We demonstrate bioelectric flight control of 757 class simulation aircraft landing at San Francisco International Airport. The physical instrumentality of a pilot control stick is not used. A pilot closes a fist in empty air and performs control movements which are captured by a dry electrode array on the arm, analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. A Vision Dome immersive display is used to create a VR world for the aircraft body mechanics and flight changes to pilot movements. Inner loop surfaces and differential aircraft thrust is controlled using a hybrid neural network architecture that combines a damage adaptive controller (Jorgensen 1998, Totah 1998) with a propulsion only based control system (Bull & Kaneshige 1997). Thus the 757 aircraft is not only being flown bioelectrically at the pilot level but also demonstrates damage adaptive neural network control permitting adaptation to severe changes in the physical flight characteristics of the aircraft at the inner loop level. To compensate for accident scenarios, the aircraft uses remaining control surface authority and differential thrust from the engines. To the best of our knowledge this is the first time real time bioelectric fine-grained control, differential thrust based control, and neural network damage adaptive control have been integrated into a single flight demonstration. The paper describes the EMG pattern recognition system and the bioelectric pattern recognition methodology.

  5. Carbon fiber enhanced bioelectricity generation in soil microbial fuel cells.

    PubMed

    Li, Xiaojing; Wang, Xin; Zhao, Qian; Wan, Lili; Li, Yongtao; Zhou, Qixing

    2016-11-15

    The soil microbial fuel cell (MFC) is a promising biotechnology for the bioelectricity recovery as well as the remediation of organics contaminated soil. However, the electricity production and the remediation efficiency of soil MFC are seriously limited by the tremendous internal resistance of soil. Conductive carbon fiber was mixed with petroleum hydrocarbons contaminated soil and significantly enhanced the performance of soil MFC. The maximum current density, the maximum power density and the accumulated charge output of MFC mixed carbon fiber (MC) were 10, 22 and 16 times as high as those of closed circuit control due to the carbon fiber productively assisted the anode to collect the electron. The internal resistance of MC reduced by 58%, 83% of which owed to the charge transfer resistance, resulting in a high efficiency of electron transfer from soil to anode. The degradation rates of total petroleum hydrocarbons enhanced by 100% and 329% compared to closed and opened circuit controls without the carbon fiber respectively. The effective range of remediation and the bioelectricity recovery was extended from 6 to 20cm with the same area of air-cathode. The mixed carbon fiber apparently enhanced the bioelectricity generation and the remediation efficiency of soil MFC by means of promoting the electron transfer rate from soil to anode. The use of conductively functional materials (e.g. carbon fiber) is very meaningful for the remediation and bioelectricity recovery in the bioelectrochemical remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Bio-electrical impedance spectroscopy: alternatives for the conventional hand-to-foot measurements.

    PubMed

    Cox-Reijven, P L M; Van Kreel, B; Soeters, P B

    2002-04-01

    Bio-impedance spectroscopy (BIS) is a very attractive method for measuring body composition. The standard method measures impedance from hand to foot. However, in patients a hand or foot is not always accessible. In these cases alternative methods would be helpful. The objective of this study was to compare BIS measurements from hand to foot (HF) with foot to foot (FF) and hand to hand (HH) measurements as alternatives. Aims were firstly, to assess the relationship between resistance (R) values measured by the different methods, secondly, to study the influence of body geometry on this relationship and lastly, to assess the predictive capacity of the methods for measuring body fluid volumes. In 53 subjects with different degrees of obesity (mean BMI = 38; SD = 9 kg/m(2)) three BIS measurements were performed from HF, HH and FF with a Xitron 4000B machine. Resistances of extracellular (Recw) and intracellular water (Ricw) were extrapolated by fitting the data to a Cole-Cole plot. Total body water (TBW) and extracellular water (ECW) were measured by deuterium and bromide dilution respectively. Intracellular water (ICW) was calculated as TBW-ECW. Anthropometric measurements, including length and circumference of limbs and trunk, were performed as measures for body geometry. The Recw, Ricw and R50 values of HF measurements could be accurately described as a function of the Recw, Ricw and R50 values of HH or FF measurements. The relative circumference of arms and legs and the length of the trunk influenced the relationship between R values of the three different measurements. The degree of overweight did not affect this relationship. The precision of the predictions of TBW, ECW and ICW based on R values of the HH measurements were comparable with the traditional HF measurements while the FF measurements gave slightly less accurate results. Under circumstances where total body BIS measurements cannot be performed, FF or HH measurements may be used as alternatives

  7. Bioelectric effect and bacterial biofilms. A systematic review

    PubMed Central

    DEL POZO, J. L.; ROUSE, M. S.; PATEL, R.

    2014-01-01

    Bacteria growing in biofilms cause a wide range of human infections. Biofilm bacteria are resistant to antimicrobics at levels 500 to 5,000 times higher than those needed to kill non-biofilm bacteria. In vitro experiments have shown that electric current can enhance the activity of some antimicrobial agents against certain bacteria in biofilms; this has been termed the “bioelectric effect”. Direct electrical current has already been safely used in humans for fracture healing. Application of direct electric current with antimicrobial chemotherapy in humans could theoretically abrogate the need to remove the device in device-related infections, a procedure associated with substantial morbidity and cost. In this article, we review what has been described in the literature with regards to the bioelectric effect. PMID:18924090

  8. Multi-frequency bioelectrical impedance analysis (BIA) compared to magnetic resonance imaging (MRI) for estimation of fat-free mass in colorectal cancer patients treated with chemotherapy.

    PubMed

    Palle, Stine S; Møllehave, Line T; Taheri-Kadkhoda, Zahra; Johansen, Susanne; Larsen, Lisbeth; Hansen, Janne W; Jensen, Nikolaj K G; Elingaard, Anette O; Møller, Alice H; Larsen, Karen; Andersen, Jens R

    2016-12-01

    Changes in body composition in cancer patients during chemotherapy are associated with treatment related toxicities or mortalities. Thus, it is relevant to identify accessible, relatively inexpensive, portable and reliable tools for evaluation of body composition in cancer patients during the course of their treatments. To examine relationships between single cross-sectional thighs magnetic resonance imaging (MRI), skeletal muscle mass (SM) as reference and multi-frequency bioelectrical impedance analysis (BIA) fat free mass (FFM) in patients with colorectal cancer undergoing chemotherapy. In an observational, prospective study we examine the relationships between single cross-sectional thighs MRI (T1-weighted (1.5 T) SM compared to FFM BIA (8-electrodes multi-frequency Tanita MC780MA)) and FFM skin-fold thickness (ST) (4-points (Harpenden, Skinfold Caliper)) and SM equation for non-obese persons from Lee et al. 2000 (L2000) (based on age, height, weight, sex and race). FFM and SM (kg) were calculated based on either area (MRI) or weight. 18 CRC patients (10 males and 8 females) with mean (SD) age 67 yr (6) were measured at baseline, and 13 were available for follow-up. BIA overestimated FFM kg for all 31 measurements with mean (SD) 18.0 kg (6.0) compared to the MRI. ST overestimated FFM kg with mean 12.4 kg (6.2) and L2000 underestimated SM kg in 18 measurements and overestimated in 13 with a total mean of -4.3 kg (6.8). BIA and ST were the best alternatives to MRI as they showed constant and thereby correctable errors. The equation, L2000, carried the smallest average measurement error but it was non-constant. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

  9. Correlation of Gastroesophageal reflux disease Assessment Symptom Questionnaire to impedance-pH measurements in children.

    PubMed

    Prachuapthunyachart, Sittichoke; Jarasvaraparn, Chaowapong; Gremse, David A

    2017-01-01

    individual symptom scores for vomiting (r 2 = 0.1569, p = 0.045), and the impedance score and the composite symptom scores (r 2 = 0.2916, p = 0.004). However, there were no significant correlations between fussiness, irritability, or abdominal pain-related multichannel intraluminal impedance-pH results and the individual symptom scores for abdominal pain. The impedance scores from multichannel intraluminal impedance-pH studies correlate with coughing/gagging/choking and vomiting in infants with gastroesophageal reflux disease. There are no significant correlations among the reflux index and impedance score versus the Gastroesophageal reflux disease Assessment Symptom Questionnaire scores for abdominal pain. We conclude that in infants with gastroesophageal reflux disease, multichannel intraluminal impedance-pH studies are more likely to demonstrate an association between gastroesophageal reflux disease and symptoms of coughing, gagging, or choking compared to an association between gastroesophageal reflux disease and pain in infants.

  10. Correlation of Gastroesophageal reflux disease Assessment Symptom Questionnaire to impedance-pH measurements in children

    PubMed Central

    Prachuapthunyachart, Sittichoke; Jarasvaraparn, Chaowapong; Gremse, David A

    2017-01-01

    .026), the impedance score and individual symptom scores for vomiting (r2 = 0.1569, p = 0.045), and the impedance score and the composite symptom scores (r2 = 0.2916, p = 0.004). However, there were no significant correlations between fussiness, irritability, or abdominal pain–related multichannel intraluminal impedance-pH results and the individual symptom scores for abdominal pain. Conclusion: The impedance scores from multichannel intraluminal impedance-pH studies correlate with coughing/gagging/choking and vomiting in infants with gastroesophageal reflux disease. There are no significant correlations among the reflux index and impedance score versus the Gastroesophageal reflux disease Assessment Symptom Questionnaire scores for abdominal pain. We conclude that in infants with gastroesophageal reflux disease, multichannel intraluminal impedance-pH studies are more likely to demonstrate an association between gastroesophageal reflux disease and symptoms of coughing, gagging, or choking compared to an association between gastroesophageal reflux disease and pain in infants. PMID:29276590

  11. Comparison of total body water estimates from O-18 and bioelectrical response prediction equations

    NASA Technical Reports Server (NTRS)

    Barrows, Linda H.; Inners, L. Daniel; Stricklin, Marcella D.; Klein, Peter D.; Wong, William W.; Siconolfi, Steven F.

    1993-01-01

    Identification of an indirect, rapid means to measure total body water (TBW) during space flight may aid in quantifying hydration status and assist in countermeasure development. Bioelectrical response testing and hydrostatic weighing were performed on 27 subjects who ingested O-18, a naturally occurring isotope of oxygen, to measure true TBW. TBW estimates from three bioelectrical response prediction equations and fat-free mass (FFM) were compared to TBW measured from O-18. A repeated measures MANOVA with post-hoc Dunnett's Test indicated a significant (p less than 0.05) difference between TBW estimates from two of the three bioelectrical response prediction equations and O-18. TBW estimates from FFM and the Kushner & Schoeller (1986) equation yielded results that were similar to those given by O-18. Strong correlations existed between each prediction method and O-18; however, standard errors, identified through regression analyses, were higher for the bioelectrical response prediction equations compared to those derived from FFM. These findings suggest (1) the Kushner & Schoeller (1986) equation may provide a valid measure of TBW, (2) other TBW prediction equations need to be identified that have variability similar to that of FFM, and (3) bioelectrical estimates of TBW may prove valuable in quantifying hydration status during space flight.

  12. Flexible implementation of front-end bioelectric signal amplifier using FPAA for telemedicine system.

    PubMed

    Chan, U Fai; Chan, Wai Wong; Pun, Sio Hang; Vai, Mang I; Mak, Peng Un

    2007-01-01

    Traditional/Current electronic circuits for Telemedicine have significant performance on certain bioelectric signal detection. However, it is rarely seen that can handle multiple signals without changing of hardware. This paper introduces a general front-end amplifier for various bioelectric signals based on Field Programmable Analogy Array (FPAA) Technology. Employing FPAA technology, the implemented amplifier can be adapted for various bioelectric signals without alternating the circuitry while its compact size (core parts < 2 cm2) provides an alternative solution for miniaturized Telemedicine system and Wearable Devices. The proposed design implementation has demonstrated, through successfully ECG and EMG signal extractions, a quick way to miniaturize analog biomedical circuit in a convenient and cost effective way.

  13. Bioelectric modulation of macrophage polarization

    NASA Astrophysics Data System (ADS)

    Li, Chunmei; Levin, Michael; Kaplan, David L.

    2016-02-01

    Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

  14. A Comparison of Three Methods to Measure Percent Body Fat on Mentally Retarded Adults.

    ERIC Educational Resources Information Center

    Burkett, Lee N.; And Others

    1994-01-01

    Reports a study that compared three measures for determining percent body fat in mentally retarded adults (multiple skinfolds and circumference measurements, Infrared Interactance, and Bioelectrical Impedance). Results indicated the Bioelectrical Impedance Analyzer and Infrared Interactance Analyzer produced values for percent body fat that were…

  15. Low-noise two-wired buffer electrodes for bioelectric amplifiers.

    PubMed

    Degen, Thomas; Torrent, Simon; Jäckel, Heinz

    2007-07-01

    Active buffer electrodes are known to improve the immunity of bioelectric recordings against power line interferences. A survey of published work reveals that buffer electrodes are almost exclusively designed using operational amplifiers (opamps). In this paper, we discuss the advantage of utilizing a single transistor instead. This allows for a simple electrode, which is small and requires only two wires. In addition, a single transistor adds considerably less noise when compared to an opamp with the same power consumption. We then discuss output resistance and gain as well as their respective effect on the common mode rejection ratio (CMRR). Finally, we demonstrate the use of two-wired buffer electrodes for a bioelectric amplifier.

  16. Evaluation of the BOD POD and leg-to-leg bioelectrical impedance analysis for estimating percent body fat in National Collegiate Athletic Association Division III collegiate wrestlers.

    PubMed

    Dixon, Curt B; Deitrick, Ronald W; Pierce, Joseph R; Cutrufello, Paul T; Drapeau, Linda L

    2005-02-01

    The purpose of this study was to compare percent body fat (%BF) estimated by air displacement plethysmography (ADP) and leg-to-leg bioelectrical impedance analysis (LBIA) with hydrostatic weighing (HW) in a group (n = 25) of NCAA Division III collegiate wrestlers. Body composition was assessed during the preseason wrestling weight certification program (WCP) using the NCAA approved methods (HW, 3-site skinfold [SF], and ADP) and LBIA, which is currently an unaccepted method of assessment. A urine specific gravity less than 1.020, measured by refractometry, was required before all testing. Each subject had all of the assessments performed on the same day. LBIA measurements (Athletic mode) were determined using a Tanita body fat analyzer (model TBF-300A). Hydrostatic weighing, corrected for residual lung volume, was used as the criterion measurement. The %BF data (mean +/- SD) were LBIA (12.3 +/- 4.6), ADP (13.8 +/- 6.3), SF (14.2 +/- 5.3), and HW (14.5 +/- 6.0). %BF estimated by LBIA was significantly (p < 0.01) smaller than HW and SF. There were no significant differences in body density or %BF estimated by ADP, SF, and HW. All methods showed significant correlations (r = 0.80-0.96; p < 0.01) with HW. The standard errors of estimate (SEE) for %BF were 1.68, 1.87, and 3.60%; pure errors (PE) were 1.88, 1.94, and 4.16% (ADP, SF, and LBIA, respectively). Bland-Atman plots for %BF demonstrated no systematic bias for ADP, SF, and LBIA when compared with HW. These preliminary findings support the use of ADP and SF for estimating %BF during the NCAA WCP in Division III wrestlers. LBIA, which consistently underestimated %BF, is not supported by these data as a valid assessment method for this athletic group.

  17. The bioelectric code: An ancient computational medium for dynamic control of growth and form.

    PubMed

    Levin, Michael; Martyniuk, Christopher J

    2018-02-01

    What determines large-scale anatomy? DNA does not directly specify geometrical arrangements of tissues and organs, and a process of encoding and decoding for morphogenesis is required. Moreover, many species can regenerate and remodel their structure despite drastic injury. The ability to obtain the correct target morphology from a diversity of initial conditions reveals that the morphogenetic code implements a rich system of pattern-homeostatic processes. Here, we describe an important mechanism by which cellular networks implement pattern regulation and plasticity: bioelectricity. All cells, not only nerves and muscles, produce and sense electrical signals; in vivo, these processes form bioelectric circuits that harness individual cell behaviors toward specific anatomical endpoints. We review emerging progress in reading and re-writing anatomical information encoded in bioelectrical states, and discuss the approaches to this problem from the perspectives of information theory, dynamical systems, and computational neuroscience. Cracking the bioelectric code will enable much-improved control over biological patterning, advancing basic evolutionary developmental biology as well as enabling numerous applications in regenerative medicine and synthetic bioengineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Body Composition of Bangladeshi Children: Comparison and Development of Leg-to-Leg Bioelectrical Impedance Equation

    PubMed Central

    Khan, I.; Hawlader, Sophie Mohammad Delwer Hossain; Arifeen, Shams El; Moore, Sophie; Hills, Andrew P.; Wells, Jonathan C.; Persson, Lars-Åke; Kabir, Iqbal

    2012-01-01

    The aim of this study was to investigate the validity of the Tanita TBF 300A leg-to-leg bioimpedance analyzer for estimating fat-free mass (FFM) in Bangladeshi children aged 4-10 years and to develop novel prediction equations for use in this population, using deuterium dilution as the reference method. Two hundred Bangladeshi children were enrolled. The isotope dilution technique with deuterium oxide was used for estimation of total body water (TBW). FFM estimated by Tanita was compared with results of deuterium oxide dilution technique. Novel prediction equations were created for estimating FFM, using linear regression models, fitting child's height and impedance as predictors. There was a significant difference in FFM and percentage of body fat (BF%) between methods (p<0.01), Tanita underestimating TBW in boys (p=0.001) and underestimating BF% in girls (p<0.001). A basic linear regression model with height and impedance explained 83% of the variance in FFM estimated by deuterium oxide dilution technique. The best-fit equation to predict FFM from linear regression modelling was achieved by adding weight, sex, and age to the basic model, bringing the adjusted R2 to 89% (standard error=0.90, p<0.001). These data suggest Tanita analyzer may be a valid field-assessment technique in Bangladeshi children when using population-specific prediction equations, such as the ones developed here. PMID:23082630

  19. Bioelectrical coupling in multicellular domains regulated by gap junctions: A conceptual approach.

    PubMed

    Cervera, Javier; Pietak, Alexis; Levin, Michael; Mafe, Salvador

    2018-04-21

    We review the basic concepts involved in bioelectrically-coupled multicellular domains, focusing on the role of membrane potentials (V mem ). In the first model, single-cell V mem is modulated by two generic polarizing and depolarizing ion channels, while intercellular coupling is implemented via voltage-gated gap junctions. Biochemical and bioelectrical signals are integrated via a feedback loop between V mem and the transcription and translation of a protein forming an ion channel. The effective rate constants depend on the single-cell V mem because these potentials modulate the local concentrations of signaling molecules and ions. This electrochemically-based idealization of the complex biophysical problem suggests that the spatio-temporal map of single-cell potentials can influence downstream patterning processes by means of the voltage-gated gap junction interconnectivity, much as in the case of electronic devices where the control of electric potentials and currents allows the local modulation of the circuitry to achieve full functionality. An alternative theoretical approach, the BioElectrical Tissue Simulation Engine (BETSE), is also presented. The BETSE modeling environment utilizes finite volume techniques to simulate bioelectric states from the perspective of ion concentrations and fluxes. This model has been successfully applied to make predictions and explain experimental observations in a variety of embryonic, regenerative, and oncogenic contexts. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. A Bioassay System Using Bioelectric Signals from Small Fish

    NASA Astrophysics Data System (ADS)

    Terawaki, Mitsuru; Soh, Zu; Hirano, Akira; Tsuji, Toshio

    Although the quality of tap water is generally examined using chemical assay, this method cannot be used for examination in real time. Against such a background, the technique of fish bioassay has attracted attention as an approach that enables constant monitoring of aquatic contamination. The respiratory rhythms of fish are considered an efficient indicator for the ongoing assessment of water quality, since they are sensitive to chemicals and can be indirectly measured from bioelectric signals generated by breathing. In order to judge aquatic contamination accurately, it is necessary to measure bioelectric signals from fish swimming freely as well as to stably discriminate measured signals, which vary between individuals. However, no bioassay system meeting the above requirements has yet been established. This paper proposes a bioassay system using bioelectric signals generated from small fish in free-swimming conditions. The system records signals using multiple electrodes to cover the extensive measurement range required in a free-swimming environment, and automatically discriminates changes in water quality from signal frequency components. This discrimination is achieved through an ensemble classification method using probability neural networks to solve the problem of differences between individual fish. The paper also reports on the results of related validation experiments, which showed that the proposed system was able to stably discriminate between water conditions before and after bleach exposure.

  1. Heterogeneous silicon mesostructures for lipid-supported bioelectric interfaces

    PubMed Central

    Jiang, Yuanwen; Carvalho-de-Souza, João L.; Wong, Raymond C. S.; Luo, Zhiqiang; Isheim, Dieter; Zuo, Xiaobing; Nicholls, Alan W.; Jung, Il Woong; Yue, Jiping; Liu, Di-Jia; Wang, Yucai; De Andrade, Vincent; Xiao, Xianghui; Navrazhnykh, Luizetta; Weiss, Dara E.; Wu, Xiaoyang; Seidman, David N.; Bezanilla, Francisco; Tian, Bozhi

    2017-01-01

    Silicon-based materials have widespread application as biophysical tools and biomedical devices. Here we introduce a biocompatible and degradable mesostructured form of silicon with multiscale structural and chemical heterogeneities. The material was synthesized using mesoporous silica as a template through a chemical-vapor-deposition process. It has an amorphous atomic structure, an ordered nanowire-based framework, and random submicrometre voids, and shows an average Young’s modulus that is 2–3 orders of magnitude smaller than that of single crystalline silicon. In addition, we used the heterogeneous silicon mesostructures to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permits non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Our findings suggest that the biomimetic expansion of silicon into heterogeneous and deformable forms can open up opportunities in extracellular biomaterial or bioelectric systems. PMID:27348576

  2. A Case of Aerophagia Diagnosed by Multichannel Intraluminal Impedance Monitoring.

    PubMed

    Sohn, Ki Chang; Jeong, Young Hoon; Jo, Dong Ho; Heo, Won Gak; Yeom, Dong Han; Choi, Suck Chei; Ryu, Han Seung

    2015-11-01

    Aerophagia is a disorder caused by abnormal accumulation of air in the gastrointestinal tract as a result of repetitive and frequent inflow of air through the mouth. For the diagnosis of this condition, it is difficult to objectively measure the air swallowing. However, multichannel intraluminal impedance monitoring facilitates the differential diagnosis between normal air swallowing and pathologic aerophagia, and can aid in the determination of the frequency and amount of air swallowed. In this report, in addition to a literature review, we describe a case of 36-year-old man with abdominal distension who was diagnosed with aerophagia using esophageal impedance monitoring and was treated with clonazepam.

  3. The performance of integrated transconductance amplifiers as variable current sources for bio-electric impedance measurements.

    PubMed

    Smith, D N

    1992-01-01

    Multiple applied current impedance measurement systems require numbers of current sources which operate simultaneously at the same frequency and within the same phase but at variable amplitudes. Investigations into the performance of some integrated operational transconductance amplifiers as variable current sources are described. Measurements of breakthrough, non-linearity and common-mode output levels for LM13600, NE5517 and CA3280 were carried out. The effects of such errors on the overall performance and stability of multiple current systems when driving floating loads are considered.

  4. Endogenous voltage gradients as mediators of cell-cell communication: strategies for investigating bioelectrical signals during pattern formation

    PubMed Central

    Adams, Dany S.; Levin, Michael

    2013-01-01

    Alongside the well-known chemical modes of cell-cell communication, we find an important and powerful system of bioelectrical signaling: changes in the resting voltage potential (Vmem) of the plasma membrane driven by ion channels, pumps and gap junctions. Slow Vmem changes in all cells serve as a highly conserved, information-bearing pathway that regulates cell proliferation, migration and differentiation. In embryonic and regenerative pattern formation and in the disorganization of neoplasia, bioelectrical cues serve as mediators of large-scale anatomical polarity, organ identity and positional information. Recent developments have resulted in tools that enable a high-resolution analysis of these biophysical signals and their linkage with upstream and downstream canonical genetic pathways. Here, we provide an overview for the study of bioelectric signaling, focusing on state-of-the-art approaches that use molecular physiology and developmental genetics to probe the roles of bioelectric events functionally. We highlight the logic, strategies and well-developed technologies that any group of researchers can employ to identify and dissect ionic signaling components in their own work and thus to help crack the bioelectric code. The dissection of bioelectric events as instructive signals enabling the orchestration of cell behaviors into large-scale coherent patterning programs will enrich on-going work in diverse areas of biology, as biophysical factors become incorporated into our systems-level understanding of cell interactions. PMID:22350846

  5. Early bioelectric activities mediate redox-modulated regeneration

    PubMed Central

    Ferreira, Fernando; Luxardi, Guillaume; Reid, Brian

    2016-01-01

    Reactive oxygen species (ROS) and electric currents modulate regeneration; however, the interplay between biochemical and biophysical signals during regeneration remains poorly understood. We investigate the interactions between redox and bioelectric activities during tail regeneration in Xenopus laevis tadpoles. We show that inhibition of NADPH oxidase-mediated production of ROS, or scavenging or blocking their diffusion into cells, impairs regeneration and consistently regulates the dynamics of membrane potential, transepithelial potential (TEP) and electric current densities (JI) during regeneration. Depletion of ROS mimics the altered TEP and JI observed in the non-regenerative refractory period. Short-term application of hydrogen peroxide (H2O2) rescues (from depleted ROS) and induces (from the refractory period) regeneration, TEP increase and JI reversal. H2O2 is therefore necessary for and sufficient to induce regeneration and to regulate TEP and JI. Epistasis assays show that voltage-gated Na+ channels act downstream of H2O2 to modulate regeneration. Altogether, these results suggest a novel mechanism for regeneration via redox-bioelectric orchestration. PMID:27827821

  6. Early bioelectric activities mediate redox-modulated regeneration.

    PubMed

    Ferreira, Fernando; Luxardi, Guillaume; Reid, Brian; Zhao, Min

    2016-12-15

    Reactive oxygen species (ROS) and electric currents modulate regeneration; however, the interplay between biochemical and biophysical signals during regeneration remains poorly understood. We investigate the interactions between redox and bioelectric activities during tail regeneration in Xenopus laevis tadpoles. We show that inhibition of NADPH oxidase-mediated production of ROS, or scavenging or blocking their diffusion into cells, impairs regeneration and consistently regulates the dynamics of membrane potential, transepithelial potential (TEP) and electric current densities (J I ) during regeneration. Depletion of ROS mimics the altered TEP and J I observed in the non-regenerative refractory period. Short-term application of hydrogen peroxide (H 2 O 2 ) rescues (from depleted ROS) and induces (from the refractory period) regeneration, TEP increase and J I reversal. H 2 O 2 is therefore necessary for and sufficient to induce regeneration and to regulate TEP and J I Epistasis assays show that voltage-gated Na + channels act downstream of H 2 O 2 to modulate regeneration. Altogether, these results suggest a novel mechanism for regeneration via redox-bioelectric orchestration. © 2016. Published by The Company of Biologists Ltd.

  7. Clinical utility of bioelectrical impedance analysis in patients with locoregional muscle invasive or metastatic urothelial carcinoma: a subanalysis of changes in body composition during neoadjuvant systemic chemotherapy.

    PubMed

    Miyake, Makito; Owari, Takuya; Iwamoto, Takashi; Morizawa, Yosuke; Hori, Shunta; Marugami, Nagaaki; Shimada, Keiji; Iida, Kota; Ohnishi, Kenta; Gotoh, Daisuke; Tatsumi, Yoshihiro; Nakai, Yasushi; Inoue, Takeshi; Anai, Satoshi; Torimoto, Kazumasa; Aoki, Katsuya; Yoneda, Tatsuo; Tanaka, Nobumichi; Fujimoto, Kiyohide

    2018-04-01

    The aim of this study was to determine the clinical utility of bioelectrical impedance analysis (BIA) in a cohort of patients with advanced urothelial carcinoma (UC). We prospectively evaluated body composition in 35 patients with locoregional muscle invasive (≥ T2 and N0-2M0) or metastatic UC. Body composition was evaluated using multifrequency BIA at baseline (n = 35) and during chemotherapy in patients receiving neoadjuvant chemotherapy (n = 14). The BIA-predicted body composition index was compared with the computed tomography-measured muscle index and the prognostic nutrition index. Changes in body composition during neoadjuvant chemotherapy were recorded and compared with the incidence of hematological adverse events. There was a significant correlation between the BIA-predicted skeletal muscle index and the computed tomography-measured skeletal muscle index (P = 0.004), while there was no significant correlation between the prognostic nutrition index and the BIA-predicted nutrition index. After the completion of 3 cycles of neoadjuvant chemotherapy, the skeletal muscle index showed a significant decrease (P = 0.016), while the total body fat mass (P = 0.025), body fat percentage (P = 0.013), and body mass index (P = 0.004) showed a significant increase (a tendency toward "sarcopenic obesity"). Patients who experienced grade 2-3 anemia during neoadjuvant chemotherapy showed a significantly lower increase in body mass index compared with patients who did not experience high-grade toxicities (P = 0.032). BIA could contribute to other methods of nutrition and muscle assessment for pretreatment risk stratification in patients with UC. Further study of a larger cohort is required to elucidate the clinical impact of changes in body composition during chemotherapy.

  8. Conversion of Wastes to Bioelectricity, Bioethanol, and Fertilizer.

    PubMed

    Khan, Abdul Majeed; Hussain, Muhammad Shoukat

    2017-08-01

      This research article presents production of bioelectricity, bioethanol, and fertilizer from different industrial wastewaters supplemented with waste fruit and vegetables. Bioelectricity was generated from wastewater through the development of different microbial fuel cells (MFCs). It was observed that the voltage was increased in series combination, whereas current was increased in parallel combinations. The series combination of four units of single-chamber and eight units of double-chamber MFCs produced the power output of 5.43 mW and 4.08 mW, respectively, which is sufficient to light up the light emitting diode (LED). Power output was increased by the addition of waste fruit and vegetables. The leftover filtrates of MFCs were used for the production of bioethanol using Saccharomyces cerevisiae, while residues were used as fertilizer to check the growth of okra plant. The result showed that minor amount of bioethanol is produced from different samples, which was confirmed by the preparation of ethylbenzoate derivative.

  9. Heterogeneous silicon mesostructures for lipid-supported bioelectric interfaces

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jiang, Yuanwen; Carvalho-de-Souza, João L.; Wong, Raymond C. S.

    Silicon-based materials have widespread application as biophysical tools and biomedical devices. Here we introduce a biocompatible and degradable mesostructured form of silicon with multi-scale structural and chemical heterogeneities. The material was synthesized using mesoporous silica as a template through a chemical vapour deposition process. It has an amorphous atomic structure, an ordered nanowire-based framework and random submicrometre voids, and shows an average Young’s modulus that is 2–3 orders of magnitude smaller than that of single-crystalline silicon. In addition, we used the heterogeneous silicon mesostructures to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permitsmore » non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Our findings suggest that the biomimetic expansion of silicon into heterogeneous and deformable forms can open up opportunities in extracellular biomaterial or bioelectric systems.« less

  10. The influence of transient change of total body water on relative body fats based on three bioelectrical impedance analyses methods. Comparison between before and after exercise with sweat loss, and after drinking.

    PubMed

    Demura, S; Yamaji, S; Goshi, F; Nagasawa, Y

    2002-03-01

    The purpose of this study was to clarify the influence of change of total body water caused by exercise and drinking, on relative body fat (%BF) based on three bioelectrical impedance analyses (BIA) methods, between hand and foot (H-F), between hand and hand (H-H), and between foot and foot (F-F). The subjects were 30 Japanese healthy young adults aged 18 to 23 years (15 males, 15 females). Measurements were made three times for each BIA method; before and after exercise with sweat, and after drinking, and also twice according to the under water weighing (UW) method, before exercise and after drinking. A pedaling exercise, with a bicycle ergometer, was used for 60 minutes as the exercise. The relationship of %BF between the UW method and each BIA method was mid-range or more (r=0.765-0.839). However, %BF based on the H-F and F-F BIA methods were higher than that based on the UW method. After drinking, %BF of all the BIA methods were higher than the UW method. %BF of the BIA methods after exercise indicated values lower than those before exercise. %BF of the H-F and H-H BIA methods after drinking were a little higher than those before exercise, indicating that those measurements reflect a slight change of body water. It was demonstrated that %BF of any BIA method reflect the change of body water caused by exercise, sweating, and drinking.

  11. Bioelectric memory: modeling resting potential bistability in amphibian embryos and mammalian cells.

    PubMed

    Law, Robert; Levin, Michael

    2015-10-15

    Bioelectric gradients among all cells, not just within excitable nerve and muscle, play instructive roles in developmental and regenerative pattern formation. Plasma membrane resting potential gradients regulate cell behaviors by regulating downstream transcriptional and epigenetic events. Unlike neurons, which fire rapidly and typically return to the same polarized state, developmental bioelectric signaling involves many cell types stably maintaining various levels of resting potential during morphogenetic events. It is important to begin to quantitatively model the stability of bioelectric states in cells, to understand computation and pattern maintenance during regeneration and remodeling. To facilitate the analysis of endogenous bioelectric signaling and the exploitation of voltage-based cellular controls in synthetic bioengineering applications, we sought to understand the conditions under which somatic cells can stably maintain distinct resting potential values (a type of state memory). Using the Channelpedia ion channel database, we generated an array of amphibian oocyte and mammalian membrane models for voltage evolution. These models were analyzed and searched, by simulation, for a simple dynamical property, multistability, which forms a type of voltage memory. We find that typical mammalian models and amphibian oocyte models exhibit bistability when expressing different ion channel subsets, with either persistent sodium or inward-rectifying potassium, respectively, playing a facilitative role in bistable memory formation. We illustrate this difference using fast sodium channel dynamics for which a comprehensive theory exists, where the same model exhibits bistability under mammalian conditions but not amphibian conditions. In amphibians, potassium channels from the Kv1.x and Kv2.x families tend to disrupt this bistable memory formation. We also identify some common principles under which physiological memory emerges, which suggest specific strategies for

  12. Treating a pressure ulcer with bio-electric stimulation therapy.

    PubMed

    Hampton, Sylvie; Collins, Fiona

    Mr Jones lived independently until he developed necrotic pressure ulcers over his heels and could no longer mobilize to care for himself. He was transferred to a nursing home where he lived for 18 months and where the nurses could care for his wounds. The wound had been on his right heel without changing over the 18 months and, although attempts to hydrate the eschar had been somewhat successful, the necrotic tissue proved stubborn creating large quantity of fibrous slough. Mr Jones was initially assessed by the tissue viability consultant on 14 March 2005 and agreed to the application of bio-electric stimulation therapy (POSiFEC). The wound change was immediate and was fully healed by 16 June 2005, 12 weeks after his initial assessment. This article outlines his care and the background to bio-electrical stimulation in wounds.

  13. Greater transportation energy and GHG offsets from bioelectricity than ethanol.

    PubMed

    Campbell, J E; Lobell, D B; Field, C B

    2009-05-22

    The quantity of land available to grow biofuel crops without affecting food prices or greenhouse gas (GHG) emissions from land conversion is limited. Therefore, bioenergy should maximize land-use efficiency when addressing transportation and climate change goals. Biomass could power either internal combustion or electric vehicles, but the relative land-use efficiency of these two energy pathways is not well quantified. Here, we show that bioelectricity outperforms ethanol across a range of feedstocks, conversion technologies, and vehicle classes. Bioelectricity produces an average of 81% more transportation kilometers and 108% more emissions offsets per unit area of cropland than does cellulosic ethanol. These results suggest that alternative bioenergy pathways have large differences in how efficiently they use the available land to achieve transportation and climate goals.

  14. On the use of The Bio-Impedance technique for Body Composition Measurements

    NASA Astrophysics Data System (ADS)

    Huerta-Franco, R.; Vargas-Luna, M.; González-Solís, J. L.; Gutiérrez-Juárez, G.

    2003-09-01

    Reviewing the methods and physical principles used in body composition measurements (BCM), it is evident that more accurate, reliable, and easily handled methods are required. The use of bio-impedance analysis (BIA) has been very useful in BCM. This technique, in the single frequency mode, has some commercial versions to perform BCM. However these apparatus have significant variability in the BCM values. The multi-frequency option of the bio-impedance technique has still a lot of challenges to overcome. We studied the variability of the body impedance spectrum (from 1 Hz to 1 MHz) in a group of subjects compared to the values obtained from commercial apparatus. We compared different anatomical body regions, some of them with less subcutaneous body fat (frontal, anterior tibial, knee, and frontal regions); others with more subcutaneous body fat (pectoral, abdominal, and internal calf regions). In order to model the bio-impedance spectrum, we analyzed layered samples with different thickness and material composition.

  15. Assessment of bioelectrical activity of synergistic muscles during pelvic floor muscles activation in postmenopausal women with and without stress urinary incontinence: a preliminary observational study

    PubMed Central

    Ptaszkowski, Kuba; Paprocka-Borowicz, Małgorzata; Słupska, Lucyna; Bartnicki, Janusz; Dymarek, Robert; Rosińczuk, Joanna; Heimrath, Jerzy; Dembowski, Janusz; Zdrojowy, Romuald

    2015-01-01

    Objective Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman’s ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI. Materials and methods This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity. Results Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups. Conclusion In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the

  16. Assessment of bioelectrical activity of synergistic muscles during pelvic floor muscles activation in postmenopausal women with and without stress urinary incontinence: a preliminary observational study.

    PubMed

    Ptaszkowski, Kuba; Paprocka-Borowicz, Małgorzata; Słupska, Lucyna; Bartnicki, Janusz; Dymarek, Robert; Rosińczuk, Joanna; Heimrath, Jerzy; Dembowski, Janusz; Zdrojowy, Romuald

    2015-01-01

    Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman's ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI. This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity. Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups. In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the mechanism of continence.

  17. An equivalent body surface charge model representing three-dimensional bioelectrical activity

    NASA Technical Reports Server (NTRS)

    He, B.; Chernyak, Y. B.; Cohen, R. J.

    1995-01-01

    A new surface-source model has been developed to account for the bioelectrical potential on the body surface. A single-layer surface-charge model on the body surface has been developed to equivalently represent bioelectrical sources inside the body. The boundary conditions on the body surface are discussed in relation to the surface-charge in a half-space conductive medium. The equivalent body surface-charge is shown to be proportional to the normal component of the electric field on the body surface just outside the body. The spatial resolution of the equivalent surface-charge distribution appears intermediate between those of the body surface potential distribution and the body surface Laplacian distribution. An analytic relationship between the equivalent surface-charge and the surface Laplacian of the potential was found for a half-space conductive medium. The effects of finite spatial sampling and noise on the reconstruction of the equivalent surface-charge were evaluated by computer simulations. It was found through computer simulations that the reconstruction of the equivalent body surface-charge from the body surface Laplacian distribution is very stable against noise and finite spatial sampling. The present results suggest that the equivalent body surface-charge model may provide an additional insight to our understanding of bioelectric phenomena.

  18. Bioelectric modulation of wound healing in a 3D in vitro model of tissue-engineered bone.

    PubMed

    Sundelacruz, Sarah; Li, Chunmei; Choi, Young Jun; Levin, Michael; Kaplan, David L

    2013-09-01

    Long-standing interest in bioelectric regulation of bone fracture healing has primarily focused on exogenous stimulation of bone using applied electromagnetic fields. Endogenous electric signals, such as spatial gradients of resting potential among non-excitable cells in vivo, have also been shown to be important in cell proliferation, differentiation, migration, and tissue regeneration, and may therefore have as-yet unexplored therapeutic potential for regulating wound healing in bone tissue. To study this form of bioelectric regulation, there is a need for three-dimensional (3D) in vitro wound tissue models that can overcome limitations of current in vivo models. We present a 3D wound healing model in engineered bone tissue that serves as a pre-clinical experimental platform for studying electrophysiological regulation of wound healing. Using this system, we identified two electrophysiology-modulating compounds, glibenclamide and monensin, that augmented osteoblast mineralization. Of particular interest, these compounds displayed differential effects in the wound area compared to the surrounding tissue. Several hypotheses are proposed to account for these observations, including the existence of heterogeneous subpopulations of osteoblasts that respond differently to bioelectric signals, or the capacity of the wound-specific biochemical and biomechanical environment to alter cell responses to electrophysiological treatments. These data indicate that a comprehensive characterization of the cellular, biochemical, biomechanical, and bioelectrical components of in vitro wound models is needed to develop bioelectric strategies to control cell functions for improved bone regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Usefulness of combining admission brain natriuretic peptide (BNP) plus hospital discharge bioelectrical impedance vector analysis (BIVA) in predicting 90 days cardiovascular mortality in patients with acute heart failure.

    PubMed

    Santarelli, Simona; Russo, Veronica; Lalle, Irene; De Berardinis, Benedetta; Navarin, Silvia; Magrini, Laura; Piccoli, Antonio; Codognotto, Marta; Castello, Luigi Maria; Avanzi, Gian Carlo; Villacorta, Humberto; Precht, Bernardo Luiz Campanário; de Araújo Porto, Pilar Barreto; Villacorta, Aline Sterque; Di Somma, Salvatore

    2017-06-01

    Heart failure is a disease characterized by high prevalence and mortality, and frequent rehospitalizations. The aim of this study is to investigate the prognostic power of combining brain natriuretic peptide (BNP) and congestion status detected by bioelectrical impedance vector analysis (BIVA) in acute heart failure patients. This is an observational, prospective, and a multicentre study. BNP assessment was measured upon hospital arrival, while BIVA analysis was obtained at the time of discharge. Cardiovascular deaths were evaluated at 90 days by a follow up phone call. 292 patients were enrolled. Compared to survivors, BNP was higher in the non-survivors group (mean value 838 vs 515 pg/ml, p < 0.001). At discharge, BIVA shows a statistically significant difference in hydration status between survivors and non-survivors [respectively, hydration index (HI) 85 vs 74, p < 0.001; reactance (Xc) 26.7 vs 37, p < 0.001; resistance (R) 445 vs 503, p < 0.01)]. Discharge BIVA shows a prognostic value in predicting cardiovascular death [HI: area under the curve (AUC) 0.715, 95% confidence interval (95% CI) 0.65-0.76; p < 0.004; Xc: AUC 0.712, 95% CI 0.655-0.76, p < 0.007; R: AUC 0.65, 95% CI 0.29-0.706, p < 0.0247]. The combination of BIVA with BNP gives a greater prognostic power for cardiovascular mortality [combined receiving operating characteristic (ROC): AUC 0.74; 95% CI 0.68-0.79; p < 0.001]. In acute heart failure patients, higher BNP levels upon hospital admission, and congestion detected by BIVA at discharge have a significant predictive value for 90 days cardiovascular mortality. The combined use of admission BNP and BIVA discharge seems to be a useful tool for increasing prognostic power in these patients.

  20. Bioelectricity-AQA, one of the first MOOC courses in engineering.

    PubMed

    Barr, Roger C

    2014-01-01

    Bioelectricity-AQA was one of the first massively open online courses in engineering, having been given the first time via Coursera starting in September, 2012. This report provides some detail on its background, presentation, enrollment, and lessons learned.

  1. The body electric 2.0: recent advances in developmental bioelectricity for regenerative and synthetic bioengineering.

    PubMed

    Mathews, Juanita; Levin, Michael

    2018-04-20

    Breakthroughs in biomedicine and synthetic bioengineering require predictive, rational control over anatomical structure and function. Recent successes in manipulating cellular and molecular hardware have not been matched by progress in understanding the patterning software implemented during embryogenesis and regeneration. A fundamental capability gap is driving desired changes in growth and form to address birth defects and traumatic injury. Here we review new tools, results, and conceptual advances in an exciting emerging field: endogenous non-neural bioelectric signaling, which enables cellular collectives to make global decisions and implement large-scale pattern homeostasis. Spatially distributed electric circuits regulate gene expression, organ morphogenesis, and body-wide axial patterning. Developmental bioelectricity facilitates the interface to organ-level modular control points that direct patterning in vivo. Cracking the bioelectric code will enable transformative progress in bioengineering and regenerative medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Enhanced microbial reduction of vanadium (V) in groundwater with bioelectricity from microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Hao, Liting; Zhang, Baogang; Tian, Caixing; Liu, Ye; Shi, Chunhong; Cheng, Ming; Feng, Chuanping

    2015-08-01

    Bioelectricity generated from the microbial fuel cell (MFC) is applied to the bioelectrical reactor (BER) directly to enhance microbial reduction of vanadium (V) (V(V)) in groundwater. With the maximum power density of 543.4 mW m-2 from the MFC, V(V) removal is accelerated with efficiency of 93.6% during 12 h operation. Higher applied voltage can facilitate this process. V(V) removals decrease with the increase of initial V(V) concentration, while extra addition of chemical oxygen demand (COD) has little effect on performance improvement. Microbial V(V) reduction is enhanced and then suppressed with the increase of conductivity. High-throughput 16S rRNA gene pyrosequencing analysis implies the accumulated Enterobacter and Lactococcus reduce V(V) with products from fermentative microorganisms such as Macellibacteroides. The presentation of electrochemically active bacteria as Enterobacter promotes electron transfers. This study indicates that application of bioelectricity from MFCs is a promising strategy to improve the efficiency of in-situ bioremediation of V(V) polluted groundwater.

  3. Bioelectricity-AQA, one of the first MOOC courses in Engineering

    PubMed Central

    Barr, Roger C.

    2014-01-01

    Bioelectricity-AQA was one of the first massively open online courses in engineering, having been given the first time via Coursera starting in September, 2012. This report provides some detail on its background, presentation, enrollment, and lessons learned. PMID:25570327

  4. Accelerating bioelectric functional development of neural stem cells by graphene coupling: Implications for neural interfacing with conductive materials.

    PubMed

    Guo, Rongrong; Zhang, Shasha; Xiao, Miao; Qian, Fuping; He, Zuhong; Li, Dan; Zhang, Xiaoli; Li, Huawei; Yang, Xiaowei; Wang, Ming; Chai, Renjie; Tang, Mingliang

    2016-11-01

    In order to govern cell-specific behaviors in tissue engineering for neural repair and regeneration, a better understanding of material-cell interactions, especially the bioelectric functions, is extremely important. Graphene has been reported to be a potential candidate for use as a scaffold and neural interfacing material. However, the bioelectric evolvement of cell membranes on these conductive graphene substrates remains largely uninvestigated. In this study, we used a neural stem cell (NSC) model to explore the possible changes in membrane bioelectric properties - including resting membrane potentials and action potentials - and cell behaviors on graphene films under both proliferation and differentiation conditions. We used a combination of single-cell electrophysiological recordings and traditional cell biology techniques. Graphene did not affect the basic membrane electrical parameters (capacitance and input resistance), but resting membrane potentials of cells on graphene substrates were more strongly negative under both proliferation and differentiation conditions. Also, NSCs and their progeny on graphene substrates exhibited increased firing of action potentials during development compared to controls. However, graphene only slightly affected the electric characterizations of mature NSC progeny. The modulation of passive and active bioelectric properties on the graphene substrate was accompanied by enhanced NSC differentiation. Furthermore, spine density, synapse proteins expressions and synaptic activity were all increased in graphene group. Modeling of the electric field on conductive graphene substrates suggests that the electric field produced by the electronegative cell membrane is much higher on graphene substrates than that on control, and this might explain the observed changes of bioelectric development by graphene coupling. Our results indicate that graphene is able to accelerate NSC maturation during development, especially with regard to

  5. Prognostic value of decreased peripheral congestion detected by Bioelectrical Impedance Vector Analysis (BIVA) in patients hospitalized for acute heart failure: BIVA prognostic value in acute heart failure.

    PubMed

    Santarelli, Simona; Russo, Veronica; Lalle, Irene; De Berardinis, Benedetta; Vetrone, Francesco; Magrini, Laura; Di Stasio, Enrico; Piccoli, Antonio; Codognotto, Marta; Mion, Monica M; Castello, Luigi M; Avanzi, Gian Carlo; Di Somma, Salvatore

    2017-06-01

    The objective of this study was to investigate the prognostic role of quantitative reduction of congestion during hospitalization assessed by Bioelectrical Impedance Vector Analysis (BIVA) serial evaluations in patients admitted for acute heart failure (AHF). AHF is a frequent reason for patients to be admitted. Exacerbation of chronic heart failure is linked with a progressive worsening of the disease with increased incidence of death. Fluid overload is the main mechanism underlying acute decompensation in these patients. BIVA is a validated technique able to quantify fluid overload. a prospective, multicentre, observational study in AHF and no AHF patients in three Emergency Departments centres in Italy. Clinical data and BIVA evaluations were performed at admission (t0) and discharge (tdis). A follow-up phone call was carried out at 90 days. Three hundred and thirty-six patients were enrolled (221 AHF and 115 no AHF patients). We found that clinical signs showed the most powerful prognostic relevance. In particular the presence of rales and lower limb oedema at tdis were linked with events relapse at 90 days. At t0, congestion detected by BIVA was observed only in the AHF group, and significantly decreased at tdis. An increase of resistance variation (dR/H) >11 Ω/m during hospitalization was associated with survival. BIVA showed significant results in predicting total events, both at t0 (area under the curve (AUC) 0.56, p<0.04) and at tdis (AUC 0.57, p<0.03). When combined with clinical signs, BIVA showed a very good predictive value for cardiovascular events at 90 days (AUC 0.97, p<0.0001). In AHF patients, an accurate physical examination evaluating the presence of rales and lower limbs oedema remains the cornerstone in the management of patients with AHF. A congestion reduction, obtained as a consequence of therapies and detected through BIVA analysis, with an increase of dR/H >11 Ω/m during hospitalization seems to be associated with increased 90 day

  6. Scaling and the frequency dependence of Nyquist plot maxima of the electrical impedance of the human thigh.

    PubMed

    Shiffman, Carl

    2017-11-30

    To define and elucidate the properties of reduced-variable Nyquist plots. Non-invasive measurements of the electrical impedance of the human thigh. A retrospective analysis of the electrical impedances of 154 normal subjects measured over the past decade shows that 'scaling' of the Nyquist plots for human thigh muscles is a property shared by healthy thigh musculature, irrespective of subject and the length of muscle segment. Here the term scaling signifies the near and sometimes 'perfect' coalescence of the separate X versus R plots into one 'reduced' Nyquist plot by the simple expedient of dividing R and X by X m , the value of X at the reactance maximum. To the extent allowed by noise levels one can say that there is one 'universal' reduced Nyquist plot for the thigh musculature of healthy subjects. There is one feature of the Nyquist curves which is not 'universal', however, namely the frequency f m at which the maximum in X is observed. That is found to vary from 10 to 100 kHz. depending on subject and segment length. Analysis shows, however, that the mean value of 1/f m is an accurately linear function of segment length, though there is a small subject-to-subject random element as well. Also, following the recovery of an otherwise healthy victim of ankle fracture demonstrates the clear superiority of measurements above about 800 kHz, where scaling is not observed, in contrast to measurements below about 400 kHz, where scaling is accurately obeyed. The ubiquity of 'scaling' casts new light on the interpretation of impedance results as they are used in electrical impedance myography and bioelectric impedance analysis.

  7. The cardio-respiratory effects of intra-abdominal hypertension: Considerations for critical care nursing practice.

    PubMed

    Christensen, Martin; Craft, Judy

    2018-02-01

    Intra-abdominal hypertension can be classified as either primary or secondary. Primary intra-abdominal hypertension is often associated through trauma or diseases of the abdominopelvic region such as pancreatitis or abdominal surgery, while secondary intra-abdominal hypertension is the result of extra-abdominal causes such as sepsis or burns. The critically ill patient offers some challenges in monitoring in particular secondary intra-abdominal hypertension because of the effects of fluid resuscitation, the use of inotropes and positive pressure ventilation. Recent work suggests that intensive care unit nurses are often unaware of the secondary effects of intra-abdominal pressure and therefore this is not monitored effectively. Therefore being aware of the cardio-respiratory effects may alert theintensive care nurse nurse to the development of intra-abdominal hypertension. The aim of this paper is to discuss the pathophysiology associated with the cardio-respiratory effects seen with intra-abdominal hypertension in the critically ill. In particular it will discuss how intra-abdominal hypertension can inadvertently be overlooked because of the low flow states that it produces which could be misconstrued as something else. It will also discuss how intra-abdominal hypertension impedes ventilation and respiratory mechanics which can often result in a non-cardiogenic pulmonary oedema. To close, the paper will offer some implications for critical care nursing practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Are ethnic and gender specific equations needed to derive fat free mass from bioelectrical impedance in children of South asian, black african-Caribbean and white European origin? Results of the assessment of body composition in children study.

    PubMed

    Nightingale, Claire M; Rudnicka, Alicja R; Owen, Christopher G; Donin, Angela S; Newton, Sian L; Furness, Cheryl A; Howard, Emma L; Gillings, Rachel D; Wells, Jonathan C K; Cook, Derek G; Whincup, Peter H

    2013-01-01

    Bioelectrical impedance analysis (BIA) is a potentially valuable method for assessing lean mass and body fat levels in children from different ethnic groups. We examined the need for ethnic- and gender-specific equations for estimating fat free mass (FFM) from BIA in children from different ethnic groups and examined their effects on the assessment of ethnic differences in body fat. Cross-sectional study of children aged 8-10 years in London Primary schools including 325 South Asians, 250 black African-Caribbeans and 289 white Europeans with measurements of height, weight and arm-leg impedance (Z; Bodystat 1500). Total body water was estimated from deuterium dilution and converted to FFM. Multilevel models were used to derive three types of equation {A: FFM = linear combination(height+weight+Z); B: FFM = linear combination(height(2)/Z); C: FFM = linear combination(height(2)/Z+weight)}. Ethnicity and gender were important predictors of FFM and improved model fit in all equations. The models of best fit were ethnicity and gender specific versions of equation A, followed by equation C; these provided accurate assessments of ethnic differences in FFM and FM. In contrast, the use of generic equations led to underestimation of both the negative South Asian-white European FFM difference and the positive black African-Caribbean-white European FFM difference (by 0.53 kg and by 0.73 kg respectively for equation A). The use of generic equations underestimated the positive South Asian-white European difference in fat mass (FM) and overestimated the positive black African-Caribbean-white European difference in FM (by 4.7% and 10.1% respectively for equation A). Consistent results were observed when the equations were applied to a large external data set. Ethnic- and gender-specific equations for predicting FFM from BIA provide better estimates of ethnic differences in FFM and FM in children, while generic equations can misrepresent these ethnic differences.

  9. Are Ethnic and Gender Specific Equations Needed to Derive Fat Free Mass from Bioelectrical Impedance in Children of South Asian, Black African-Caribbean and White European Origin? Results of the Assessment of Body Composition in Children Study

    PubMed Central

    Nightingale, Claire M.; Rudnicka, Alicja R.; Owen, Christopher G.; Donin, Angela S.; Newton, Sian L.; Furness, Cheryl A.; Howard, Emma L.; Gillings, Rachel D.; Wells, Jonathan C. K.; Cook, Derek G.; Whincup, Peter H.

    2013-01-01

    Background Bioelectrical impedance analysis (BIA) is a potentially valuable method for assessing lean mass and body fat levels in children from different ethnic groups. We examined the need for ethnic- and gender-specific equations for estimating fat free mass (FFM) from BIA in children from different ethnic groups and examined their effects on the assessment of ethnic differences in body fat. Methods Cross-sectional study of children aged 8–10 years in London Primary schools including 325 South Asians, 250 black African-Caribbeans and 289 white Europeans with measurements of height, weight and arm-leg impedance (Z; Bodystat 1500). Total body water was estimated from deuterium dilution and converted to FFM. Multilevel models were used to derive three types of equation {A: FFM = linear combination(height+weight+Z); B: FFM = linear combination(height2/Z); C: FFM = linear combination(height2/Z+weight)}. Results Ethnicity and gender were important predictors of FFM and improved model fit in all equations. The models of best fit were ethnicity and gender specific versions of equation A, followed by equation C; these provided accurate assessments of ethnic differences in FFM and FM. In contrast, the use of generic equations led to underestimation of both the negative South Asian-white European FFM difference and the positive black African-Caribbean-white European FFM difference (by 0.53 kg and by 0.73 kg respectively for equation A). The use of generic equations underestimated the positive South Asian-white European difference in fat mass (FM) and overestimated the positive black African-Caribbean-white European difference in FM (by 4.7% and 10.1% respectively for equation A). Consistent results were observed when the equations were applied to a large external data set. Conclusions Ethnic- and gender-specific equations for predicting FFM from BIA provide better estimates of ethnic differences in FFM and FM in children, while generic equations can

  10. The Evaluation of Bioelectrical Activity of Pelvic Floor Muscles Depending on Probe Location: A Pilot Study

    PubMed Central

    Słupska, Lucyna

    2013-01-01

    Objectives. The main objective was to determine how the depth of probe placement affects functional and resting bioelectrical activity of the PFM and whether the recorded signal might be dependent on the direction in which the probe is rotated. Participants. The study comprised of healthy, nulliparous women between the ages of 21 and 25. Outcome Measures. Bioelectric activity of the PFM was recorded from four locations of the vagina by surface EMG and vaginal probe. Results. There were no statistically significant differences between the results during functional sEMG activity. During resting sEMG activity, the highest bioelectrical activity of the PFM was observed in the L1 and the lowest in the L4 and a statistically significant difference between the highest and the lowest results of resting sEMG activity was observed (P = 0.0043). Conclusion. Different electrodes placement during functional contraction of PFM does not affect the obtained results in sEMG evaluation. In order to diagnose the highest resting activity of PFM the recording plates should be placed toward the anterior vaginal wall and distally from the introitus. However, all of the PFM have similar bioelectrical activity and it seems that these muscles could be treated as a single muscle. PMID:24392449

  11. Intra-Abdominal Hypertension and Abdominal Compartment Syndrome after Abdominal Wall Reconstruction: Quaternary Syndromes?

    PubMed

    Kirkpatrick, A W; Nickerson, D; Roberts, D J; Rosen, M J; McBeth, P B; Petro, C C; Berrevoet, Frederik; Sugrue, M; Xiao, Jimmy; Ball, C G

    2017-06-01

    Reconstruction with reconstitution of the container function of the abdominal compartment is increasingly being performed in patients with massive ventral hernia previously deemed inoperable. This situation places patients at great risk of severe intra-abdominal hypertension and abdominal compartment syndrome if organ failure ensues. Intra-abdominal hypertension and especially abdominal compartment syndrome may be devastating systemic complications with systematic and progressive organ failure and death. We thus reviewed the pathophysiology and reported clinical experiences with abnormalities of intra-abdominal pressure in the context of abdominal wall reconstruction. Bibliographic databases (1950-2015), websites, textbooks, and the bibliographies of previously recovered articles for reports or data relating to intra-abdominal pressure, intra-abdominal hypertension, and the abdominal compartment syndrome in relation to ventral, incisional, or abdominal hernia repair or abdominal wall reconstruction. Surgeons should thus consider and carefully measure intra-abdominal pressure and its resultant effects on respiratory parameters and function during abdominal wall reconstruction. The intra-abdominal pressure post-operatively will be a result of the new intra-peritoneal volume and the abdominal wall compliance. Strategies surgeons may utilize to ameliorate intra-abdominal pressure rise after abdominal wall reconstruction including temporizing paralysis of the musculature either temporarily or semi-permanently, pre-operative progressive pneumoperitoneum, permanently removing visceral contents, or surgically releasing the musculature to increase the abdominal container volume. In patients without complicating shock and inflammation, and in whom the abdominal wall anatomy has been so functionally adapted to maximize compliance, intra-abdominal hypertension may be transient and tolerable. Intra-abdominal hypertension/abdominal compartment syndrome in the specific setting of

  12. Investigation of the Optimum Farming Temperature for Grifola frondosa and Growth Promotion using the Bio-Electric Potential as an Index

    NASA Astrophysics Data System (ADS)

    Yanagibashi, Hideyuki; Hirama, Junji; Matsuda, Masato; Miyamoto, Toshio

    The purpose of this study was to investigate the optimum farming conditions for mushrooms from the view point of engineering field. As the bio-electric potential of mushrooms is considered to be closely related to the activation of mushroom cells, this relationship has been used to analyze the dependence of the morphogenetic characteristics of Grifola frondosa on farming temperatures (from 16 to 22 degree C). The experimental results indicated that a maximum response was exhibited, with correspondingly favorable morphogenesis obtained at 18 degree C. Based on the experimental results, including those in a previous study, it was assumed that the larger the bio-electric potential becomes, the higher the growth yield reaches. In order to support this assumption, growth promotion was conducted by intentionally activating the bio-electric potential within the mushrooms by stimulating them with short bursts of illumination. The resulting observation of growth promotion permitted the conclusion that the bio-electric potential can, indeed, be regarded as an index of growth.

  13. Bioelectric patterning during oogenesis: stage-specific distribution of membrane potentials, intracellular pH and ion-transport mechanisms in Drosophila ovarian follicles.

    PubMed

    Krüger, Julia; Bohrmann, Johannes

    2015-01-16

    Bioelectric phenomena have been found to exert influence on various developmental and regenerative processes. Little is known about their possible functions and the cellular mechanisms by which they might act during Drosophila oogenesis. In developing follicles, characteristic extracellular current patterns and membrane-potential changes in oocyte and nurse cells have been observed that partly depend on the exchange of protons, potassium ions and sodium ions. These bioelectric properties have been supposed to be related to various processes during oogenesis, e. g. pH-regulation, osmoregulation, cell communication, cell migration, cell proliferation, cell death, vitellogenesis and follicle growth. Analysing in detail the spatial distribution and activity of the relevant ion-transport mechanisms is expected to elucidate the roles that bioelectric phenomena play during oogenesis. To obtain an overview of bioelectric patterning along the longitudinal and transversal axes of the developing follicle, the spatial distributions of membrane potentials (Vmem), intracellular pH (pHi) and various membrane-channel proteins were studied systematically using fluorescent indicators, fluorescent inhibitors and antisera. During mid-vitellogenic stages 9 to 10B, characteristic, stage-specific Vmem-patterns in the follicle-cell epithelium as well as anteroposterior pHi-gradients in follicle cells and nurse cells were observed. Corresponding distribution patterns of proton pumps (V-ATPases), voltage-dependent L-type Ca(2+)-channels, amiloride-sensitive Na(+)-channels and Na(+),H(+)-exchangers (NHE) and gap-junction proteins (innexin 3) were detected. In particular, six morphologically distinguishable follicle-cell types are characterized on the bioelectric level by differences concerning Vmem and pHi as well as specific compositions of ion channels and carriers. Striking similarities between Vmem-patterns and activity patterns of voltage-dependent Ca(2+)-channels were found, suggesting

  14. Evaluation of electrical broad bandwidth impedance spectroscopy as a tool for body composition measurement in cows in comparison with body measurements and the deuterium oxide dilution method.

    PubMed

    Schäff, C T; Pliquett, U; Tuchscherer, A; Pfuhl, R; Görs, S; Metges, C C; Hammon, H M; Kröger-Koch, C

    2017-05-01

    Body fatness and degree of body fat mobilization in cows vary enormously during their reproduction cycle and influence energy partitioning and metabolic adaptation. The objective of the study was to test bioelectrical impedance spectroscopy (BIS) as a method for predicting fat depot mass (FDM), in living cows. The FDM is defined as the sum of subcutaneous, omental, mesenteric, retroperitoneal, and carcass fat mass. Bioelectrical impedance spectroscopy is compared with the prediction of FDM from the deuterium oxide (DO) dilution method and from body conformation measurements. Charolais × Holstein Friesian (HF; = 18; 30 d in milk) crossbred cows and 2 HF (lactating and nonlactating) cows were assessed by body conformation measurements, BIS, and the DO dilution method. The BCS of cows was a mean of 3.68 (SE 0.64). For the DO dilution method, a bolus of 0.23 g/kg BW DO (60 atom%) was intravenously injected and deuterium (D) enrichment was analyzed in plasma and whey by stabile isotope mass spectrometry, and total body water content was calculated. Impedance measurement was performed using a 4-electrode interface and time domain-based measurement system consisting of a voltage/current converter for applying current stimulus and an amplifier for monitoring voltage across the sensor electrodes. For the BIS, we used complex impedances over three frequency decades that delivers information on intra- and extracellular water and capacity of cell membranes. Impedance data (resistance of extra- and intracellular space, cell membrane capacity, and phase angle) were extracted 1) by simple curve fit to extract the resistance at direct current and high frequency and 2) by using an electrical equivalent circuit. Cows were slaughtered 7 d after BIS and D enrichment measurements and dissected for the measurement of FDM. Multiple linear regression analyses were performed to predict FDM based on data obtained from body conformation measurements, BIS, and D enrichment, and applied

  15. Impedance-estimation methods, modeling methods, articles of manufacture, impedance-modeling devices, and estimated-impedance monitoring systems

    DOEpatents

    Richardson, John G [Idaho Falls, ID

    2009-11-17

    An impedance estimation method includes measuring three or more impedances of an object having a periphery using three or more probes coupled to the periphery. The three or more impedance measurements are made at a first frequency. Three or more additional impedance measurements of the object are made using the three or more probes. The three or more additional impedance measurements are made at a second frequency different from the first frequency. An impedance of the object at a point within the periphery is estimated based on the impedance measurements and the additional impedance measurements.

  16. Effect of Influenza-Induced Fever on Human Bioimpedance Values

    PubMed Central

    Marini, Elisabetta; Buffa, Roberto; Contreras, Monica; Magris, Magda; Hidalgo, Glida; Sanchez, Wilmer; Ortiz, Vanessa; Urbaez, Maryluz; Cabras, Stefano; Blaser, Martin J.; Dominguez-Bello, Maria G.

    2015-01-01

    Background and Aims Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. Methods Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. Results For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). Conclusions There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states. PMID:25915945

  17. Design and Application of a Circuit for Measuring Frequency and Duty Cycle of Stimulated Bioelectrical Signal

    NASA Astrophysics Data System (ADS)

    Tang, Li-Ming; Chang, Ben-Kang; Liu, Tie-Bing; Wu, Min; Ling, Gang

    2002-12-01

    To design a new type of circuit for measuring frequency & duty cycle of stimulated bioelectrical signal for the project of 'the map of neuron-threshold in human brain and its clinical application'. This circuit was designed according to the character of stimulated bioelectrical signals. It was tested and improved and then used in the neuron -threshold stimulator. The circuit was found to be very accurate for measuring frequency and the error for measuring duty cycle was below 0.2%. This circuit is well-designed, simple, easy to use, and can be applied in many systems.

  18. Bio-isolated dc operational amplifier. [for bioelectric measurements

    NASA Technical Reports Server (NTRS)

    Lee, R. D. (Inventor)

    1974-01-01

    A bio-isolated dc operational amplifier is described for use in making bioelectrical measurements of a patient while providing isolation of the patient from electrical shocks. The circuit contains a first operational amplifier coupled to the patient with its output coupled in a forward loop through a first optic coupler to a second operational amplifier. The output of the second operational amplifier is coupled to suitable monitoring circuitry via a feedback circuit including a second optic coupler to the input of the first operational amplifier.

  19. Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged >60 y from rural regions of Cuba, Chile and Mexico.

    PubMed

    Valencia, M E; Alemán-Mateo, H; Salazar, G; Hernández Triana, M

    2003-07-01

    In Latin American and Caribbean countries such as Chile, Mexico and Cuba, the population over 60 y has increased steadily. In this age group, there is scarce information about body composition, particularly for those living in rural areas. The purpose of this study was to determine body composition in free-living and healthy elderly subjects >60 y from rural areas of Chile, Cuba and Mexico using deuterium oxide dilution and bioelectrical impedance (BIA) and to develop and cross-validate a predictive equation for this group of subjects by BIA for future use as a field technique. The study included 133 healthy subjects (73 males and 60 females) >60 y from rural regions of Cuba, Chile and Mexico. Total body water, body weight, height and other anthropometric and BIA variables (resistance and reactance) were measured. Total body water was determined by deuterium oxide dilution, and fat-free mass (FFM)/fat mass were derived from this measurement. The total sample was used in a split-sample internal cross-validation. BIA and other anthropometric variables were integrated to multiple regression model to design the best predictive equation, which was validated in the other sample. ANOVA, multiple regression and Bland and Altman's procedure were used to analyze the data. Body weight, percentage of fat and fat-free mass were lower in the Cuban men and women compared with Chilean and Mexican men and women. The best predictive equation of the FFM was: FFM kg=(-7.71+(H(2)/R x 0.49)+(country or ethnicity x 1.12)+(body weight x 0.27)+(sex x 3.49)+(Xc x 0.13)), where H(2) is height(2) (cm); R is resistance (Omega); country: Chile=1, Mexico=2 and Cuba=3; sex: women=0 and men=1; body weight (kg) and Xc is reactance (Omega). R(2) was 0.944 and the root mean square error (RMSE) was 2.08 kg. The mean+/-s.d. of FFM prediction was 44.2+/-9.2 vs 44.6+/-10.1. The results of cross-validation showed no significant difference with the line of identity, showing that the predicted equation was

  20. Reprogramming cells and tissue patterning via bioelectrical pathways: molecular mechanisms and biomedical opportunities

    PubMed Central

    Levin, Michael

    2013-01-01

    Transformative impact in regenerative medicine requires more than the reprogramming of individual cells: advances in repair strategies for birth defects or injuries, tumor normalization, and the construction of bioengineered organs and tissues all require the ability to control large-scale anatomical shape. Much recent work has focused on the transcriptional and biochemical regulation of cell behaviour and morphogenesis. However, exciting new data reveal that bioelectrical properties of cells and their microenvironment exert a profound influence on cell differentiation, proliferation, and migration. Ion channels and pumps expressed in all cells, not just excitable nerve and muscle, establish resting potentials that vary across tissues and change with significant developmental events. Most importantly, the spatio-temporal gradients of these endogenous transmembrane voltage potentials (Vmem) serve as instructive patterning cues for large-scale anatomy, providing organ identity, positional information, and prepattern template cues for morphogenesis. New genetic and pharmacological techniques for molecular modulation of bioelectric gradients in vivo have revealed the ability to initiate complex organogenesis, change tissue identity, and trigger regeneration of whole vertebrate appendages. A large segment of the spatial information processing that orchestrates individual cells’ programs towards the anatomical needs of the host organism is electrical; this blurs the line between memory and decision-making in neural networks and morphogenesis in non-neural tissues. Advances in cracking this bioelectric code will enable the rational reprogramming of shape in whole tissues and organs, revolutionizing regenerative medicine, developmental biology, and synthetic bioengineering. PMID:23897652

  1. Reprogramming cells and tissue patterning via bioelectrical pathways: molecular mechanisms and biomedical opportunities.

    PubMed

    Levin, Michael

    2013-01-01

    Transformative impact in regenerative medicine requires more than the reprogramming of individual cells: advances in repair strategies for birth defects or injuries, tumor normalization, and the construction of bioengineered organs and tissues all require the ability to control large-scale anatomical shape. Much recent work has focused on the transcriptional and biochemical regulation of cell behavior and morphogenesis. However, exciting new data reveal that bioelectrical properties of cells and their microenvironment exert a profound influence on cell differentiation, proliferation, and migration. Ion channels and pumps expressed in all cells, not just excitable nerve and muscle, establish resting potentials that vary across tissues and change with significant developmental events. Most importantly, the spatiotemporal gradients of these endogenous transmembrane voltage potentials (Vmem ) serve as instructive patterning cues for large-scale anatomy, providing organ identity, positional information, and prepattern template cues for morphogenesis. New genetic and pharmacological techniques for molecular modulation of bioelectric gradients in vivo have revealed the ability to initiate complex organogenesis, change tissue identity, and trigger regeneration of whole vertebrate appendages. A large segment of the spatial information processing that orchestrates individual cells' programs toward the anatomical needs of the host organism is electrical; this blurs the line between memory and decision-making in neural networks and morphogenesis in nonneural tissues. Advances in cracking this bioelectric code will enable the rational reprogramming of shape in whole tissues and organs, revolutionizing regenerative medicine, developmental biology, and synthetic bioengineering. Copyright © 2013 Wiley Periodicals, Inc.

  2. Cell-cell bioelectrical interactions and local heterogeneities in genetic networks: a model for the stabilization of single-cell states and multicellular oscillations.

    PubMed

    Cervera, Javier; Manzanares, José A; Mafe, Salvador

    2018-04-04

    Genetic networks operate in the presence of local heterogeneities in single-cell transcription and translation rates. Bioelectrical networks and spatio-temporal maps of cell electric potentials can influence multicellular ensembles. Could cell-cell bioelectrical interactions mediated by intercellular gap junctions contribute to the stabilization of multicellular states against local genetic heterogeneities? We theoretically analyze this question on the basis of two well-established experimental facts: (i) the membrane potential is a reliable read-out of the single-cell electrical state and (ii) when the cells are coupled together, their individual cell potentials can be influenced by ensemble-averaged electrical potentials. We propose a minimal biophysical model for the coupling between genetic and bioelectrical networks that associates the local changes occurring in the transcription and translation rates of an ion channel protein with abnormally low (depolarized) cell potentials. We then analyze the conditions under which the depolarization of a small region (patch) in a multicellular ensemble can be reverted by its bioelectrical coupling with the (normally polarized) neighboring cells. We show also that the coupling between genetic and bioelectric networks of non-excitable cells, modulated by average electric potentials at the multicellular ensemble level, can produce oscillatory phenomena. The simulations show the importance of single-cell potentials characteristic of polarized and depolarized states, the relative sizes of the abnormally polarized patch and the rest of the normally polarized ensemble, and intercellular coupling.

  3. Modelling the cost-utility of bio-electric stimulation therapy compared to standard care in the treatment of elderly patients with chronic non-healing wounds in the UK.

    PubMed

    Clegg, John P; Guest, Julian F

    2007-04-01

    To estimate the cost-utility of bio-electric stimulation therapy (Posifect) compared to standard care in elderly patients with chronic, non-healing wounds of > 6 months duration, from the perspective of the National Health Service (NHS) in the UK. Clinical and resource use data from a 16 week clinical evaluation of bio-electric stimulation therapy among patients who had recalcitrant wounds were combined with utility data obtained from a standard gamble analysis to construct a 16 week Markov model. The model considers the decision by a clinician to continue with a patient's previous care plan or treat with bio-electric stimulation therapy. Unit resource costs at 2005/2006 prices were applied to the resource utilisation estimates within the model, enabling the cost-utility of bio-electric stimulation therapy compared to standard care to be estimated. The acquisition cost of Posifect had not been decided at the time of performing this study. Hence, the base case analysis used a cost of 50 pounds per dressing. 33% of all wounds are expected to heal within 16 weeks after the start of bio-electric stimulation therapy. Consequently, using bio-electric stimulation therapy is expected to lead to a 51% decrease in the number of domiciliary clinician visits, from 4.7 to 2.3 per week. The model also showed that using bio-electric stimulation therapy instead of patients' standard care is expected to reduce the NHS cost of managing them by 16% from 2287 pounds (95% CI: 1838 pounds; 2735 pounds) to 1921 pounds (95% CI: 1609 pounds; 2233 pounds) and result in a health gain of 0.023 QALYs over 16 weeks. Hence, bio-electric stimulation therapy was found to be a dominant treatment. Sensitivity analyses demonstrated that the cost-utility of using bio-electric stimulation therapy relative to standard care is very sensitive to the acquisition cost of the therapy, the acquisition cost of patients' drugs and the number of clinician visits and less sensitive to utility values and the

  4. Compost in plant microbial fuel cell for bioelectricity generation.

    PubMed

    Moqsud, M A; Yoshitake, J; Bushra, Q S; Hyodo, M; Omine, K; Strik, David

    2015-02-01

    Recycling of organic waste is an important topic in developing countries as well as developed countries. Compost from organic waste has been used for soil conditioner. In this study, an experiment has been carried out to produce green energy (bioelectricity) by using paddy plant microbial fuel cells (PMFCs) in soil mixed with compost. A total of six buckets filled with the same soil were used with carbon fiber as the electrodes for the test. Rice plants were planted in five of the buckets, with the sixth bucket containing only soil and an external resistance of 100 ohm was used for all cases. It was observed that the cells with rice plants and compost showed higher values of voltage and power density with time. The highest value of voltage showed around 700 mV when a rice plant with 1% compost mixed soil was used, however it was more than 95% less in the case of no rice plant and without compost. Comparing cases with and without compost but with the same number of rice plants, cases with compost depicted higher voltage to as much as 2 times. The power density was also 3 times higher when the compost was used in the paddy PMFCs which indicated the influence of compost on bio-electricity generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Abdominal Adhesions

    MedlinePlus

    ... Clearinghouse What are abdominal adhesions? Abdominal adhesions are bands of fibrous tissue that can form between abdominal ... Esophagus Stomach Large intestine Adhesion Abdominal adhesions are bands of fibrous tissue that can form between abdominal ...

  6. Abdominal Pain

    MedlinePlus

    ... and Recurrent or Functional Abdominal Pain (RAP or FAP) What is abdominal pain? Abdominal pain , or stomachache, ... recurrent abdominal pain (RAP) or functional abdominal pain (FAP)? If your health care provider has ruled out ...

  7. Paradoxical Air Microembolism Induces Cerebral Bioelectrical Abnormalities and Occasionally Headache in Patent Foramen Ovale Patients With Migraine

    PubMed Central

    Sevgi, Eser Başak; Erdener, Sefik Evren; Demirci, Mehmet; Topcuoglu, Mehmet Akif; Dalkara, Turgay

    2012-01-01

    Background Although controversial, paradoxical embolism via patent foramen ovale (PFO) may account for some of the migraine attacks in a subset of migraine with aura (MA) patients. Induction of MA attacks with air bubble injection during transcranial Doppler ultrasound in MA patients with PFO supports this view. It is likely that cerebral embolism in patients with right-to-left shunt induces bioelectrical abnormalities to initiate MA under some conditions. Methods and Results We investigated changes in cerebral bioelectrical activity after intravenous microbubble injection in 10 MA patients with large PFO and right-to-left cardiac shunt. Eight PFO patients without migraine but with large right-to-left shunt and 12 MA patients without PFO served as controls. Four MA patients with PFO were reexamined with sham injections of saline without microbubbles. Bioelectrical activity was evaluated using spectral electroencephalography and, passage of microbubbles through cerebral arteries was monitored with transcranial Doppler ultrasound. Microbubble embolism caused significant electroencephalographic power increase in MA+PFO patients but not in control groups including the sham-injected MA+PFO patients. Headache developed in 2 MA with PFO patients after microbubble injection. Conclusions These findings demonstrate that air microembolism through large PFOs may cause cerebral bioelectrical disturbances and, occasionally, headache in MA patients, which may reflect an increased reactivity of their brain to transient subclinical hypoxia–ischemia, and suggest that paradoxical embolism is not a common cause of migraine but may induce headache in the presence of a large PFO and facilitating conditions. PMID:23316313

  8. Enhanced vanadium (V) reduction and bioelectricity generation in microbial fuel cells with biocathode

    NASA Astrophysics Data System (ADS)

    Qiu, Rui; Zhang, Baogang; Li, Jiaxin; Lv, Qing; Wang, Song; Gu, Qian

    2017-08-01

    Microbial fuel cells (MFCs) represent a promising approach for remediation of toxic vanadium (V) contaminated environment. Herein, enhanced V(V) reduction and bioelectricity generation are realized in MFCs with biocathode. Synergistically electrochemical and microbial reductions result in the nearly complete removals of V(V) within 7 d operation with initial concentration of 200 mg L-1. Maximum power density of 529 ± 12 mW m-2 is obtained. Electrochemical tests reveal that biocathode promotes electron transfers and reduces charge transfer resistance. XPS analysis confirms that V(IV) is the main reduction product, which precipitates naturally under neutral conditions. High-throughput 16S rRNA gene sequencing analysis indicates that the newly appeared Dysgonomonas is responsible for V(V) reduction and Klebsiella contributes mainly to bioelectricity generation in MFCs with biocathode. This study further improves the performance of remediating V(V) contaminated environment based on MFC technology.

  9. Noninvasive estimation of fluid shifts between body compartments by measurement of bioelectric characteristics

    NASA Technical Reports Server (NTRS)

    Bishop, Phillip A.

    1989-01-01

    Previous research has established that bioelectrical characteristics of the human body reflect fluid status to some extent. It has been previously assumed that changes in electrical resistance (R) and reactance (X) are associated with changes in total body water (TBW). The purpose of the present pilot investigation was to assess the correspondence between body R and X and changes in estimated TBW and plasma volume during a period of bedrest (simulated weightlessness). R and X were measured pre-, during, and post- a 13 day bedrest status. Although a clear relationship was not elucidated, evidence was found suggesting that R and X reflect plasma volume rather than TBW. Indirect evidence provided by previous studies which investigated other aspects of the electrical/fluid relationship, also suggests the independence of TBW and electrical properties. With further research, a bioelectrical technique for noninvasively tracking fluid changes consequent to space flight may be developed.

  10. Bioelectrical Perchlorate Remediation

    NASA Astrophysics Data System (ADS)

    Thrash, C.; Achenbach, L. A.; Coates, J. D.

    2007-12-01

    Several bioreactor designs are currently available for the ex-situ biological attenuation of perchlorate- contaminated waters and recently, some of these reactor designs were conditionally approved by the California Department of Health Services for application in the treatment of perchlorate contaminated drinking water. However, all of these systems are dependent on the continual addition of a chemical electron donor to sustain microbial activity and are always subject to biofouling and downstream water quality issues. In addition, residual labile electron donor in the reactor effluent can stimulate microbial growth in water distribution systems and contribute to the formation of potentially toxic trihalomethanes during disinfection by chlorination. As part of our ongoing studies into microbial perchlorate reduction we investigated the ability of dissimilatory perchlorate reducing bacteria (DPRB) to metabolize perchlorate using a negatively charged electrode (cathode) in the working chamber of a bioelectrical reactor (BER) as the primary electron donor. In this instance the DPRB use the electrons on the electrode surface either directly or indirectly in the form of electrolytically produced H2 as a source of reducing equivalents for nitrate and perchlorate reduction. As part of this investigation our fed-batch studies showed that DPRB could use electrons from a graphite cathode poised at -500mV (vs. Ag/AgCl) for the reduction of perchlorate and nitrate. We isolated a novel organism, Dechlorospirillum strain VDY, from the cathode surface after 70 days operation which readily reduced 100 mg.L-1 perchlorate in a mediatorless batch bioelectrical reactor (BER) in 6 days. Continuous up-flow BERs (UFBERs) seeded with active cultures of strain VDY continuously treated waters containing 100 mg.L-1 perchlorate with almost 100% efficiency throughout their operation achieving a non-optimized volumetric loading of 60 mg.L-1 reactor volume.day-1. The same UFBERs also treated

  11. Evaluation of Nutritional Status in Children during Predialysis, or Treated By Peritoneal Dialysis or Hemodialysis.

    PubMed

    Yılmaz, Dilek; Sönmez, Ferah; Karakaş, Sacide; Yavaşcan, Önder; Aksu, Nejat; Ömürlü, İmran Kurt; Yenisey, Çiğdem

    2016-06-01

    Malnutrition is one of the major causes of morbidity and mortality in children with chronic kidney disease (CKD). The objective of this study was to evaluate nutritional status of children with stage 3-4 CKD and treated by peritoneal dialysis or hemodialysis using anthropometric measurements, biochemical parameters and bioelectrical impedance analysis. The study included a total of 52 patients and 46 healthy children. In anthropometric evaluation, the children with CKD had lower values for standard deviation score for weight, height, body mass index, skinfold thickness and mid-arm circumference than those of healthy children (p < 0.05). The fat mass (%) and the body cell mass (%) measurements performed by bioelectrical impedance analysis were lower compared with the control group (p < 0.05). It is considered that bioelectrical impedance analysis measurement should be used with anthropometric measurements, which are easy to perform, to achieve more accurate nutritional evaluation in children. © The Author [2016]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Plant Bioelectric Potential of Hard-leaf Cabbage to Irradiation-light Frequency

    NASA Astrophysics Data System (ADS)

    Tokuda, Masaki; Shao, Lixin; Oyabu, Takashi; Nanto, Hidehito

    Bioelectric potential was investigated to examine the availability of vegetable growth control. The potential is a kind of information transmitted by the vegetable and it varies markedly with one’s physiological phenomenon, light, air contaminant and insect which are external factors. Highly-efficient growth control can be made possible due to clarifying the relationship between the external factors and the potential. Vegetable can be used as a sensor in addition. A hard-leaf cabbage (Ancient specie) was adopted as a subjective plant in this study and the bioelectric potential was measured. The analysis was carried out using the summation of the potential (vm1) for one minute. The data was input every 0.1 seconds through a difference amplifier. The potential characteristic was investigated as a function of light frequency emitting from a LED panel. In addition, the potential was studied when ethyl alcohol existed and not existed as an air contaminant. As a result, it becomes obvious that the vm1 is raised when blue and red lights are irradiated. The lights mainly contribute to photosynthesis. The potential increases in the presence of ethyl alcohol which was adopted as a kind of nutrient.

  13. Abdominal tap

    MedlinePlus

    Peritoneal tap; Paracentesis; Ascites - abdominal tap; Cirrhosis - abdominal tap; Malignant ascites - abdominal tap ... abdominal cavity ( most often cancer of the ovaries ) Cirrhosis of the liver Damaged bowel Heart disease Infection ...

  14. Staged abdominal re-operation for abdominal trauma.

    PubMed

    Taviloglu, Korhan

    2003-07-01

    To review the current developments in staged abdominal re-operation for abdominal trauma. To overview the steps of damage control laparotomy. The ever increasing importance of the resuscitation phase with current intensive care unit (ICU) support techniques should be emphasized. General surgeons should be familiar to staged abdominal re-operation for abdominal trauma and collaborate with ICU teams, interventional radiologists and several other specialties to overcome this entity.

  15. Preliminary bioelectrical impedance analysis (BIA) equation for body composition assessment in young females from Colombia

    NASA Astrophysics Data System (ADS)

    Caicedo-Eraso, J. C.; González-Correa, C. H.; González-Correa, C. A.

    2013-04-01

    A previous study showed that reported BIA equations for body composition are not suitable for Colombian population. The purpose of this study was to develop and validate a preliminary BIA equation for body composition assessment in young females from Colombia, using hydrodensitometry as reference method. A sample of 30 young females was evaluated. Inclusion and exclusion criteria were defined to minimize the variability of BIA. Height, weight, BIA, residual lung volume (RV) and underwater weight (UWW) were measured. A preliminary BIA equation was developed (r2 = 0.72, SEE = 2.48 kg) by stepwise multiple regression with fat-free mass (FFM) as dependent variable and weight, height and impedance measurements as independent variables. The quality of regression was evaluated and a cross-validation against 50% of sample confirmed that results obtained with the preliminary BIA equation is interchangeable with results obtained with hydrodensitometry (r2 = 0.84, SEE = 2.62 kg). The preliminary BIA equation can be used for body composition assessment in young females from Colombia until a definitive equation is developed. The next step will be increasing the sample, including a second reference method, as deuterium oxide dilution (D2O), and using multi-frequency BIA (MF-BIA). It would also be desirable to develop equations for males and other ethnic groups in Colombia.

  16. The application of biomedical engineering techniques to the diagnosis and management of tropical diseases: a review.

    PubMed

    Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Faisal, Tarig; Neuman, Michael

    2015-03-23

    This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications.

  17. [Non-invasive estimation of aortic flow by local electrical impedance changes].

    PubMed

    Okuda, N; Ohashi, N; Yamada, M; Fujinami, T

    1986-09-01

    Aortic flow velocity was measured by catheter-tip flow transducer in 25 patients who underwent left cardiac catheterization for non-invasive estimates by the impedance method. Disk electrodes were attached to the skin at the levels of the second thoracic vertebra in the posterior median line and the V8 lead position for electrocardiography. Alternating current, 350 micro-amperes, 50 KHz constant, was applied to the outer electrode, and impedance changes were detected via the inner electrode. The e wave, or height of the first derivative dz/dt wave of the electrical impedance was lower in cases of old myocardial infarction and higher in cases of aortic valve regurgitation, as compared with the values of the healthy control group. The time lag between the start of the upward deflection and the peak value of the dz/dt wave coincided with that of the aortic flow curve as measured at the aortic arch and descending aorta. These time lags were about 20 to 30 msec as compared with the ascending aortic flow curve, and were -20 to -30 msec as compared with the abdominal aortic flow curve. There was a close correlation between the maximum flow velocity measured at the aortic arch and the height of the e waves. The regression equation was: Y = 0.21X - 1.53, r = 0.88, p less than 0.01. These data suggest that the first derivative of electrical impedance change as obtained by the disk electrode method reflects aortic flow at the arch and descending aorta.

  18. The Relationship between Chlorophyll Fluorescence Parameter (Fv/Fm) and Frequency Component of Plant Bioelectric Potential in Spraying Chemical Herbicides

    NASA Astrophysics Data System (ADS)

    Shibata, Shin-Ichi; Satou, Fumitake; Kimura, Haruhiko; Oyabu, Takashi

    Recently, there is a problem of the steady supply of food therefore plant factory has been establishing and takes off in world wide countries. In the plant factory, the growing environment can be controlled and the crop can also be controlled. The products are growing in an enclosed environment, therefore agricultural chemicals has no use. Secure and safe food producing system can be constructed. However, efficient production formula for the plant (for example vegetable) is not defined well. It is an effective way to control the growing environmental factors using physiology information which are directly obtained from the vegetable. The chlorophyll fluorescence is used as evaluation of plant condition. It is necessary to clarify the bioelectric potential in the growth condition of the plant. In this study, we examined the relationship between the chlorophyll fluorescence and the plant bioelectric potential in bad condition. The plant in spraying chemical herbicides was assumed as the condition. In future, plant physiological function and environmental response can be understood by directly monitoring the bioelectric potential.

  19. Ultrasound, anthropometry and bioimpedance: a comparison in predicting fat deposition in non-alcoholic fatty liver disease.

    PubMed

    Vitturi, Nicola; Soattin, Marta; De Stefano, Fabio; Vianello, Daniela; Zambon, Alberto; Plebani, Mario; Busetto, Luca

    2015-06-01

    The aim of our study was the evaluation of anthropometric measurements [waist circumference and sagittal abdominal diameter (SAD)] and abdominal bioelectrical impedance analysis (BIA) (ViScan, TANITA) in comparison to several abdominal ultrasonographic (US) measurements to estimate visceral fat deposition and liver steatosis in a population of 105 subjects. All 105 patients underwent a complete anthropometric evaluation, blood sample for the determination of total cholesterol, HDL cholesterol, triglycerides, glucose, insulin, high-sensitivity C-reactive protein, BIA and US measurements (peritoneal, pre-peritoneal, peri-renal, para-renal and peri-hepatic fat thickness). All the ultrasonographic markers considered in our study are related to the presence of non-alcoholic fatty liver disease (NAFLD), and so is true for SAD. Comparing ROC curves, peritoneal fat tissue thickness, SAD and ViScan visceral index are significantly better than waist circumference in predicting the presence of NAFLD (AUC 0.79 ± 0.04; 0.81 ± 0.05; 0.82 ± 0.04 vs 0.76 ± 0.05, respectively). According to our data, various methods may be useful in evaluating NAFLD, but only ViScan visceral index, US peritoneal fat thickness and SAD are better than waist circumference. Among them, SAD is the most promising, due to its small cost and time consumption.

  20. [Abdominal trauma].

    PubMed

    Sido, B; Grenacher, L; Friess, H; Büchler, M W

    2005-09-01

    Blunt abdominal trauma is much more frequent than penetrating abdominal trauma in Europe. As a consequence of improved quality of computed tomography, even complex liver injuries are increasingly being treated conservatively. However, missed hollow viscus injuries still remain a problem, as they considerably increase mortality in multiply injured patients. Laparoscopy decreases the rate of unnecessary laparotomies in perforating abdominal trauma and helps to diagnose injuries of solid organs and the diaphragm. However, the sensitivity in detecting hollow viscus injuries is low and the role of laparoscopy in blunt abdominal injury has not been defined. If intra-abdominal bleeding is difficult to control in hemodynamically unstable patients, damage control surgery with packing of the liver, total splenectomy, and provisional closure of hollow viscus injuries is of importance. Definitive surgical treatment follows hemodynamic stabilization and restoration of hemostasis. Injuries of the duodenum and pancreas after blunt abdominal trauma are often associated with other intra-abdominal injuries and the treatment depends on their location and severity.

  1. Chronic abdominal wall pain misdiagnosed as functional abdominal pain.

    PubMed

    van Assen, Tijmen; de Jager-Kievit, Jenneke W A J; Scheltinga, Marc R; Roumen, Rudi M H

    2013-01-01

    The abdominal wall is often neglected as a cause of chronic abdominal pain. The aim of this study was to identify chronic abdominal wall pain syndromes, such as anterior cutaneous nerve entrapment syndrome (ACNES), in a patient population diagnosed with functional abdominal pain, including irritable bowel syndrome, using a validated 18-item questionnaire as an identification tool. In this cross-sectional analysis, 4 Dutch primary care practices employing physicians who were unaware of the existence of ACNES were selected. A total of 535 patients ≥18 years old who were registered with a functional abdominal pain diagnosis were approached when they were symptomatic to complete the questionnaire (maximum 18 points). Responders who scored at least the 10-point cutoff value (sensitivity, 0.94; specificity, 0.92) underwent a diagnostic evaluation to establish their final diagnosis. The main outcome was the presence and prevalence of ACNES in a group of symptomatic patients diagnosed with functional abdominal pain. Of 535 patients, 304 (57%) responded; 167 subjects (31%) recently reporting symptoms completed the questionnaire. Of 23 patients who scored above the 10-point cutoff value, 18 were available for a diagnostic evaluation. In half of these subjects (n = 9) functional abdominal pain (including IBS) was confirmed. However, the other 9 patients were suffering from abdominal wall pain syndrome, 6 of whom were diagnosed with ACNES (3.6% prevalence rate of symptomatic subjects; 95% confidence interval, 1.7-7.6), whereas the remaining 3 harbored a painful lipoma, an abdominal herniation, and a painful scar. A clinically relevant portion of patients previously diagnosed with functional abdominal pain syndrome in a primary care environment suffers from an abdominal wall pain syndrome such as ACNES.

  2. The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review

    PubMed Central

    Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Faisal, Tarig; Neuman, Michael

    2015-01-01

    This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications. PMID:25806872

  3. Assessing the reliability of FTIR spectroscopy measurements and validity of bioelectrical impedance analysis as a surrogate measure of body composition among children and adolescents aged 8-19 years attending schools in Kampala, Uganda.

    PubMed

    Ndagire, Catherine T; Muyonga, John H; Isabirye, Dan; Odur, Benard; Somda, Serge M A; Bukenya, Richard; Andrade, Juan E; Nakimbugwe, Dorothy

    2018-06-04

    Accurate measurement of body composition in children and adolescents is important as the quantities of fat and fat-free mass have implications for health risk. The objectives of the present study were: to determine the reliability of Fourier Transform Infrared spectroscopy (FTIR) measurements and; compare the Fat Mass (FM), Fat Free Mass (FFM) and body fat percentage (%BF) values determined by bioelectrical impedance analysis (BIA) to those determined by deuterium dilution method (DDM) to identify correlations and agreement between the two methods. A cross-sectional study was conducted among 203 children and adolescents aged 8-19 years attending schools in Kampala city, Uganda. Pearson product-moment correlation at 5% significance level was considered for assessing correlations. Bland Altman analysis was used to examine the agreement between of FTIR measurements and between estimates by DDM and BIA.. Reliability of measurements was determined by Cronbach's alpha. There was good agreement between the in vivo D 2 O saliva enrichment measurements at 3 and 4 h among the studied age groups based on Bland-Altman plots. Cronbach's alpha revealed that measurements of D 2 O saliva enrichment had very good reliability. For children and young adolescents, DDM and BIA gave similar estimates of FFM, FM, and %BF. Among older adolescents, BIA significantly over-estimated FFM and significantly under-estimated FM and %BF compared to estimates by DDM. The correlation between FFM, FM and %BF estimates by DDM and BIA was high and significant among young and older adolescents and for FFM among children. Reliability of the FTIR spectroscopy measurements was very good among the studied population. BIA is suitable for assessing body composition among children (8-9 years) and young adolescents (10-14 years) but not among older adolescents (15-19 years) in Uganda. The body composition measurements of older adolescents determined by DDM can be predicted using those provided by BIA using

  4. [Effect of angiotensin II depot administration on bioelectric functional processes of the central nervous system].

    PubMed

    Martin, G; Baumann, H; Grieger, F

    1976-01-01

    Using the average evoked potential technique, angiotensin-II depot effects (1 mg implantate = 3--4 mg/kg body weight angiotensin-II) were studied neuroelectrophysiologically in reticular, hippocampal and neocrotical structures of albino rats. A multivariate variance and discriminance analysis program revealed differentiated changes of the bioelectrical processing data of the CNS. Evidence was obtained for a varying structural sensitivity of central-nervous substructures under depot administration of angiotensin-II. In later phases of angiotensin-II action, the hippocampus was characterized by an electrographic synchronization phenomenon with high-amplitude average evoked potentials. The reticular formation, and to a lesser extent the visual cortex, showed an angiotensin-induced diminution of bioelectrical excitation. However, the intensity of the change in functional CNS patterns did not always correlate with maximal blood pressure rises. The described changes of afference processing to standardized sensory stimuli, especially in hippocampal and reticular structures of the CNS foll owing angiotensin depot action, point to a central-nervous action mechanism of angiotensin-II.

  5. A role for bioelectric effects in the induction of bystander signals by ionizing radiation?

    PubMed

    Mothersill, C; Moran, G; McNeill, F; Gow, M D; Denbeigh, J; Prestwich, W; Seymour, C B

    2007-04-03

    The induction of "bystander effects" i.e. effects in cells which have not received an ionizing radiation track, is now accepted but the mechanisms are not completely clear. Bystander effects following high and low LET radiation exposure are accepted but mechanisms are still not understood. There is some evidence for a physical component to the signal. This paper tests the hypothesis that bioelectric or biomagnetic phenomena are involved. Human immortalized skin keratinocytes and primary explants of mouse bladder and fish skin, were exposed directly to ionizing radiation or treated in a variety of bystander protocols. Exposure of cells was conducted by shielding one group of flasks using lead, to reduce the dose below the threshold of 2mGy (60)Cobalt gamma rays established for the bystander effect. The endpoint for the bystander effect in the reporter system used was reduction in cloning efficiency (RCE). The magnitude of the RCE was similar in shielded and unshielded flasks. When cells were placed in a Faraday cage the magnitude of the RCE was less but not eliminated. The results suggest that liquid media or cell-cell contact transmission of bystander factors may be only part of the bystander mechanism. Bioelectric or bio magnetic fields may have a role to play. To test this further, cells were placed in a Magnetic Resonance Imaging (MRI) machine for 10 min using a typical head scan protocol. This treatment also induced a bystander response. Apart from the obvious clinical relevance, the MRI results further suggest that bystander effects may be produced by non-ionizing exposures. It is concluded that bioelectric or magnetic effects may be involved in producing bystander signaling cascades commonly seen following ionizing radiation exposure.

  6. A Role for Bioelectric Effects in the Induction of Bystander Signals by Ionizing Radiation?

    PubMed Central

    Mothersill, C.; Moran, G.; McNeill, F.; Gow, M.D.; Denbeigh, J.; Prestwich, W.; Seymour, C.B.

    2007-01-01

    The induction of “bystander effects” i.e. effects in cells which have not received an ionizing radiation track, is now accepted but the mechanisms are not completely clear. Bystander effects following high and low LET radiation exposure are accepted but mechanisms are still not understood. There is some evidence for a physical component to the signal. This paper tests the hypothesis that bioelectric or biomagnetic phenomena are involved. Human immortalized skin keratinocytes and primary explants of mouse bladder and fish skin, were exposed directly to ionizing radiation or treated in a variety of bystander protocols. Exposure of cells was conducted by shielding one group of flasks using lead, to reduce the dose below the threshold of 2mGy 60Cobalt gamma rays established for the bystander effect. The endpoint for the bystander effect in the reporter system used was reduction in cloning efficiency (RCE). The magnitude of the RCE was similar in shielded and unshielded flasks. When cells were placed in a Faraday cage the magnitude of the RCE was less but not eliminated. The results suggest that liquid media or cell-cell contact transmission of bystander factors may be only part of the bystander mechanism. Bioelectric or bio magnetic fields may have a role to play. To test this further, cells were placed in a Magnetic Resonance Imaging (MRI) machine for 10min using a typical head scan protocol. This treatment also induced a bystander response. Apart from the obvious clinical relevance, the MRI results further suggest that bystander effects may be produced by non-ionizing exposures. It is concluded that bioelectric or magnetic effects may be involved in producing bystander signaling cascades commonly seen following ionizing radiation exposure. PMID:18648606

  7. Biohydrogen, biomethane and bioelectricity as crucial components of biorefinery of organic wastes: a review.

    PubMed

    Poggi-Varaldo, Héctor M; Munoz-Paez, Karla M; Escamilla-Alvarado, Carlos; Robledo-Narváez, Paula N; Ponce-Noyola, M Teresa; Calva-Calva, Graciano; Ríos-Leal, Elvira; Galíndez-Mayer, Juvencio; Estrada-Vázquez, Carlos; Ortega-Clemente, Alfredo; Rinderknecht-Seijas, Noemí F

    2014-05-01

    Biohydrogen is a sustainable form of energy as it can be produced from organic waste through fermentation processes involving dark fermentation and photofermentation. Very often biohydrogen is included as a part of biorefinery approaches, which reclaim organic wastes that are abundant sources of renewable and low cost substrate that can be efficiently fermented by microorganisms. The aim of this work was to critically assess selected bioenergy alternatives from organic solid waste, such as biohydrogen and bioelectricity, to evaluate their relative advantages and disadvantages in the context of biorefineries, and finally to indicate the trends for future research and development. Biorefining is the sustainable processing of biomass into a spectrum of marketable products, which means: energy, materials, chemicals, food and feed. Dark fermentation of organic wastes could be the beach-head of complete biorefineries that generate biohydrogen as a first step and could significantly influence the future of solid waste management. Series systems show a better efficiency than one-stage process regarding substrate conversion to hydrogen and bioenergy. The dark fermentation also produces fermented by-products (fatty acids and solvents), so there is an opportunity for further combining with other processes that yield more bioenergy. Photoheterotrophic fermentation is one of them: photosynthetic heterotrophs, such as non-sulfur purple bacteria, can thrive on the simple organic substances produced in dark fermentation and light, to give more H2. Effluents from photoheterotrophic fermentation and digestates can be processed in microbial fuel cells for bioelectricity production and methanogenic digestion for methane generation, thus integrating a diverse block of bioenergies. Several digestates from bioenergies could be used for bioproducts generation, such as cellulolytic enzymes and saccharification processes, leading to ethanol fermentation (another bioenergy), thus completing

  8. Electrical impedance characterization of normal and cancerous human hepatic tissue.

    PubMed

    Laufer, Shlomi; Ivorra, Antoni; Reuter, Victor E; Rubinsky, Boris; Solomon, Stephen B

    2010-07-01

    The four-electrode method was used to measure the ex vivo complex electrical impedance of tissues from 14 hepatic tumors and the surrounding normal liver from six patients. Measurements were done in the frequency range 1-400 kHz. It was found that the conductivity of the tumor tissue was much higher than that of the normal liver tissue in this frequency range (from 0.14 +/- 0.06 S m(-1) versus 0.03 +/- 0.01 S m(-1) at 1 kHz to 0.25 +/- 0.06 S m(-1) versus 0.15 +/- 0.03 S m(-1) at 400 kHz). The Cole-Cole models were estimated from the experimental data and the four parameters (rho(0), rho(infinity), alpha, f(c)) were obtained using a least-squares fit algorithm. The Cole-Cole parameters for the cancerous and normal liver are 9 +/- 4 Omega m(-1), 2.2 +/- 0.7 Omega m(-1), 0.5 +/- 0.2, 140 +/- 103 kHz and 50 +/- 28 Omega m(-1), 3.2 +/- 0.6 Omega m(-1), 0.64 +/- 0.04, 10 +/- 7 kHz, respectively. These data can contribute to developing bioelectric applications for tissue diagnostics and in tissue treatment planning with electrical fields such as radiofrequency tissue ablation, electrochemotherapy and gene therapy with reversible electroporation, nanoscale pulsing and irreversible electroporation.

  9. Constant current loop impedance measuring system that is immune to the effects of parasitic impedances

    NASA Technical Reports Server (NTRS)

    Anderson, Karl F. (Inventor)

    1994-01-01

    A constant current loop measuring system is provided for measuring a characteristic of an environment. The system comprises a first impedance positionable in the environment, a second impedance coupled in series with said first impedance and a parasitic impedance electrically coupled to the first and second impedances. A current generating device, electrically coupled in series with the first and second impedances, provides a constant current through the first and second impedances to produce first and second voltages across the first and second impedances, respectively, and a parasitic voltage across the parasitic impedance. A high impedance voltage measuring device measures a voltage difference between the first and second voltages independent of the parasitic voltage to produce a characteristic voltage representative of the characteristic of the environment.

  10. Management of intra-abdominal hypertension and abdominal compartment syndrome: a review

    PubMed Central

    2014-01-01

    Patients in the intensive care unit (ICU) are at risk of developing of intra abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). Aim: This review seeks to define IAH and ACS, identify the aetiology and presentation of IAH and ACS, identify IAP measurement techniques, identify current management and discuss the implications of IAH and ACS for nursing practice. A search of the electronic databases was supervised by a health librarian. The electronic data bases Cumulative Index of Nursing and Allied Health Literature (CINAHL); Medline, EMBASE, and the World Wide Web was undertaken from 1996- January 2011 using MeSH and key words which included but not limited to: abdominal compartment syndrome, intra -abdominal hypertension, intra-abdominal pressure in adult populations met the search criteria and were reviewed by three authors using a critical appraisal tool. Data derived from the retrieved material are discussed under the following themes: (1) etiology of intra-abdominal hypertension; (2) strategies for measuring intra-abdominal pressure (3) the manifestation of abdominal compartment syndrome; and (4) the importance of nursing assessment, observation and interventions. Intra-abdominal pressure (IAP) and abdominal compartment syndrome (ACS) have the potential to alter organ perfusion and compromise organ function. PMID:24499574

  11. Body composition and functional assessment of nutritional status in adults: a narrative review of imaging, impedance, strength and functional techniques.

    PubMed

    Smith, S; Madden, A M

    2016-12-01

    The accurate and valid assessment of body composition is essential for the diagnostic evaluation of nutritional status, identifying relevant outcome measures, and determining the effectiveness of current and future nutritional interventions. Developments in technology and our understanding of the influences of body composition on risk and outcome will provide practitioners with new opportunities to enhance current practice and to lead future improvements in practice. This is the second of a two-part narrative review that aims to critically evaluate body composition methodology in diverse adult populations, with a primary focus on its use in the assessment and monitoring of under-nutrition. Part one focused on anthropometric variables [Madden and Smith (2016) J Hum Nutr Diet 29: 7-25] and part two focuses on the use of imaging techniques, bioelectrical impedance analysis, markers of muscle strength and functional status, with particular reference to developments relevant to practice. © 2016 The British Dietetic Association Ltd.

  12. Bioelectric Characterization of Epithelia from Neonatal CFTR Knockout Ferrets

    PubMed Central

    Fisher, John T.; Tyler, Scott R.; Zhang, Yulong; Lee, Ben J.; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R.

    2013-01-01

    Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4′-diisothiocyano-2,2′-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin–stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)–inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin–inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport. PMID:23782101

  13. Bioelectric characterization of epithelia from neonatal CFTR knockout ferrets.

    PubMed

    Fisher, John T; Tyler, Scott R; Zhang, Yulong; Lee, Ben J; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R; Engelhardt, John F

    2013-11-01

    Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4'-diisothiocyano-2,2'-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin-stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)-inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin-inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport.

  14. Abdominal epilepsy as an unusual cause of abdominal pain: a case report.

    PubMed

    Yunus, Yilmaz; Sefer, Ustebay; Dondu, Ulker Ustebay; Ismail, Ozanli; Yusuf, Ehi

    2016-09-01

    Abdominal pain, in etiology sometimes difficult to be defined, is a frequent complaint in childhood. Abdominal epilepsy is a rare cause of abdominal pain. In this article, we report on 5 year old girl patient with abdominal epilepsy. Some investigations (stool investigation, routine blood tests, ultrasonography (USG), electrocardiogram (ECHO) and electrocardiograpy (ECG), holter for 24hr.) were done to understand the origin of these complaints; but no abnormalities were found. Finally an EEG was done during an episode of abdominal pain and it was shown that there were generalized spikes especially precipitated by hyperventilation. The patient did well on valproic acid therapy and EEG was normal 1 month after beginning of the treatment. The cause of chronic recurrent paroxymal abdominal pain is difficult for the clinicians to diagnose in childhood. A lot of disease may lead to paroxysmal gastrointestinal symptoms like familial mediterranean fever and porfiria. Abdominal epilepsy is one of the rare but easily treatable cause of abdominal pain. In conclusion, abdominal epilepsy should be suspected in children with recurrent abdominal pain.

  15. Baseline impedance measured during high-resolution esophageal impedance manometry reliably discriminates GERD patients.

    PubMed

    Ravi, K; Geno, D M; Vela, M F; Crowell, M D; Katzka, D A

    2017-05-01

    Baseline impedance measured with ambulatory impedance pH monitoring (MII-pH) and a mucosal impedance catheter detects gastroesophageal reflux disease (GERD). However, these tools are limited by cost or patient tolerance. We investigated whether baseline impedance measured during high-resolution impedance manometry (HRIM) distinguishes GERD patients from controls. Consecutive patients with clinical HRIM and MII-pH testing were identified. Gastroesophageal reflux disease was defined by esophageal pH <4 for ≥5% of both the supine and total study time, whereas controls had an esophageal pH <4 for ≤3% of the study performed off PPI. Baseline impedance was measured over 15 seconds during the landmark period of HRIM and over three 10 minute intervals during the overnight period of MII-pH. Among 29 GERD patients and 26 controls, GERD patients had a mean esophageal acid exposure time of 22.7% compared to 1.2% in controls (P<.0001). Mean baseline impedance during HRIM was lower in GERD (1061 Ω) than controls (2814 Ω) (P<.0001). Baseline mucosal impedance measured during HRIM and MII-pH correlated (r=0.59, P<.0001). High-resolution esophageal manometry baseline impedance had high diagnostic accuracy for GERD, with an area under the curve (AUC) of 0.931 on receiver operating characteristics (ROC) analysis. A HRIM baseline impedance threshold of 1582 Ω had a sensitivity of 86.2% and specificity of 88.5% for GERD, with a positive predictive value of 89.3% and negative predictive value of 85.2%. Baseline impedance measured during HRIM can reliably discriminate GERD patients with at least moderate esophageal acid exposure from controls. This diagnostic tool may represent an accurate, cost-effective, and less invasive test for GERD. © 2016 John Wiley & Sons Ltd.

  16. Overview Of Impedance Sensors

    NASA Astrophysics Data System (ADS)

    Abele, John E.

    1989-08-01

    Electrical impedance has been one of the many "tools of great promise" that physicians have employed in their quest to measure and/or monitor body function or physiologic events. So far, the expectations for its success have always exceeded its performance. In simplistic terms, physiologic impedance is a measure of the resistance in the volume between electrodes which changes as a function of changes in that volume, the relative impedance of that volume, or a combination of these two. The history and principles of electrical impedance are very nicely reviewed by Geddes and Baker in their textbook "Principles of Applied Biomedical Instrumentation". It is humbling, however, to note that Cremer recorded variations in electrical impedance in frog hearts as early as 1907. The list of potential applications includes the measurement of thyroid function, estrogen activity, galvanic skin reflex, respiration, blood flow by conductivity dilution, nervous activity and eye movement. Commercial devices employing impedance have been and are being used to measure respiration (pneumographs and apneamonitors), pulse volume (impedance phlebographs) and even noninvasive cardiac output.

  17. Intra-Abdominal Hypertension and Abdominal Compartment Syndrome in Association with Ruptured Abdominal Aortic Aneurysm in the Endovascular Era: Vigilance Remains Critical

    PubMed Central

    Bozeman, Matthew C.; Ross, Charles B.

    2012-01-01

    Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are common complications of ruptured abdominal aortoiliac aneurysms (rAAAs) and other abdominal vascular catastrophes even in the age of endovascular therapy. Morbidity and mortality due to systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF) are significant. Recognition and management of IAH are key critical care measures which may decrease morbidity and improve survival in these vascular patients. Two strategies have been utilized: expectant management with prompt decompressive laparotomy upon diagnosis of threshold levels of IAH versus prophylactic, delayed abdominal closure based upon clinical parameters at the time of initial repair. Competent management of the abdominal wound with preservation of abdominal domain is also an important component of the care of these patients. In this review, we describe published experience with IAH and ACS complicating abdominal vascular catastrophes, experience with ACS complicating endovascular repair of rAAAs, and techniques for management of the abdominal wound. Vigilance and appropriate management of IAH and ACS remains critically important in decreasing morbidity and optimizing survival following catastrophic intra-abdominal vascular events. PMID:22454763

  18. Intra-abdominal hypertension and abdominal compartment syndrome in association with ruptured abdominal aortic aneurysm in the endovascular era: vigilance remains critical.

    PubMed

    Bozeman, Matthew C; Ross, Charles B

    2012-01-01

    Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are common complications of ruptured abdominal aortoiliac aneurysms (rAAAs) and other abdominal vascular catastrophes even in the age of endovascular therapy. Morbidity and mortality due to systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF) are significant. Recognition and management of IAH are key critical care measures which may decrease morbidity and improve survival in these vascular patients. Two strategies have been utilized: expectant management with prompt decompressive laparotomy upon diagnosis of threshold levels of IAH versus prophylactic, delayed abdominal closure based upon clinical parameters at the time of initial repair. Competent management of the abdominal wound with preservation of abdominal domain is also an important component of the care of these patients. In this review, we describe published experience with IAH and ACS complicating abdominal vascular catastrophes, experience with ACS complicating endovascular repair of rAAAs, and techniques for management of the abdominal wound. Vigilance and appropriate management of IAH and ACS remains critically important in decreasing morbidity and optimizing survival following catastrophic intra-abdominal vascular events.

  19. Abdominal Assessment.

    PubMed

    Fritz, Deborah; Weilitz, Pamela Becker

    2016-03-01

    Abdominal pain is one of the most common complaints by patients, and assessment of abdominal pain and associated symptoms can be challenging for home healthcare providers. Reasons for abdominal pain are related to inflammation, organ distention, and ischemia. The history and physical examination are important to narrow the source of acute or chronic problems, identify immediate interventions, and when necessary, facilitate emergency department care.

  20. Abdominal Aortic Aneurysm

    MedlinePlus

    ... Kids and Teens Pregnancy and Childbirth Women Men Seniors Your Health Resources Healthcare Management End-of-Life ... familydoctor.org editorial staff Categories: Family Health, Men, Seniors, WomenTags: abdominal aorta, abdominal aortic aneurysm, abdominal pain, ...

  1. Bioelectrical activity of limb muscles during cold shivering of stimulation of the vestibular apparatus

    NASA Technical Reports Server (NTRS)

    Kuzmina, G. I.

    1980-01-01

    The effects of caloric and electric stimulation of the vestibular receptors on the EMG activity of limb muslces in anesthetized cats during cold induced shivering involved flexor muscles alone. Both types of stimulation suppressed bioelectrical activity more effectively in the ipsilateral muscles. The suppression of shivering activity seems to be due to the increased inhibitory effect of descending labyrinth pathways on the function of flexor motoneurons.

  2. Resting potential, oncogene-induced tumorigenesis, and metastasis: the bioelectric basis of cancer in vivo

    NASA Astrophysics Data System (ADS)

    Lobikin, Maria; Chernet, Brook; Lobo, Daniel; Levin, Michael

    2012-12-01

    Cancer may result from localized failure of instructive cues that normally orchestrate cell behaviors toward the patterning needs of the organism. Steady-state gradients of transmembrane voltage (Vmem) in non-neural cells are instructive, epigenetic signals that regulate pattern formation during embryogenesis and morphostatic repair. Here, we review molecular data on the role of bioelectric cues in cancer and present new findings in the Xenopus laevis model on how the microenvironment's biophysical properties contribute to cancer in vivo. First, we investigated the melanoma-like phenotype arising from serotonergic signaling by ‘instructor’ cells—a cell population that is able to induce a metastatic phenotype in normal melanocytes. We show that when these instructor cells are depolarized, blood vessel patterning is disrupted in addition to the metastatic phenotype induced in melanocytes. Surprisingly, very few instructor cells need to be depolarized for the hyperpigmentation phenotype to occur; we present a model of antagonistic signaling by serotonin receptors that explains the unusual all-or-none nature of this effect. In addition to the body-wide depolarization-induced metastatic phenotype, we investigated the bioelectrical properties of tumor-like structures induced by canonical oncogenes and cancer-causing compounds. Exposure to carcinogen 4-nitroquinoline 1-oxide (4NQO) induces localized tumors, but has a broad (and variable) effect on the bioelectric properties of the whole body. Tumors induced by oncogenes show aberrantly high sodium content, representing a non-invasive diagnostic modality. Importantly, depolarized transmembrane potential is not only a marker of cancer but is functionally instructive: susceptibility to oncogene-induced tumorigenesis is significantly reduced by forced prior expression of hyperpolarizing ion channels. Importantly, the same effect can be achieved by pharmacological manipulation of endogenous chloride channels, suggesting

  3. Endogenous Voltage Potentials and the Microenvironment: Bioelectric Signals that Reveal, Induce and Normalize Cancer

    PubMed Central

    Chernet, Brook; Levin, Michael

    2014-01-01

    Cancer may be a disease of geometry: a misregulation of the field of information that orchestrates individual cells’ activities towards normal anatomy. Recent work identified molecular mechanisms underlying a novel system of developmental control: bioelectric gradients. Endogenous spatio-temporal differences in resting potential of non-neural cells provide instructive cues for cell regulation and complex patterning during embryogenesis and regeneration. It is now appreciated that these cues are an important layer of the dysregulation of cell: cell interactions that leads to cancer. Abnormal depolarization of resting potential (Vmem) is a convenient marker for neoplasia and activates a metastatic phenotype in genetically-normal cells in vivo. Moreover, oncogene expression depolarizes cells that form tumor-like structures, but is unable to form tumors if this depolarization is artificially prevented by misexpression of hyperpolarizing ion channels. Vmem triggers metastatic behaviors at considerable distance, mediated by transcriptional and epigenetic effects of electrically-modulated flows of serotonin and butyrate. While in vivo data on voltages in carcinogenesis comes mainly from the amphibian model, unbiased genetic screens and network profiling in rodents and human tissues reveal several ion channel proteins as bona fide oncogene and promising targets for cancer drug development. However, we propose that a focus on specific channel genes is just the tip of the iceberg. Bioelectric state is determined by post-translational gating of ion channels, not only from genetically-specified complements of ion translocators. A better model is a statistical dynamics view of spatial Vmem gradients. Cancer may not originate at the single cell level, since gap junctional coupling results in multi-cellular physiological networks with multiple stable attractors in bioelectrical state space. New medical applications await a detailed understanding of the mechanisms by which organ

  4. [Evaluation of anger expression, school functioning and a level of anxiety in children and adolescents with functional abdominal pain].

    PubMed

    Marczyńska, Paulina; Kowalkowska, Katarzyna; Kuczyńska, Renata; Czerwionka-Szaflarska, Mieczysława; Krogulska, Aneta

    Psychosocial conditions may have influence on the occurrence of functional abdominal pain. Anxiety, school-related difficulties and suppression of emotions negatively impact on the psychosocial condition of a child and could impede its treatment. The analysis of the psychosocial determinants of functioning of children and adolescents with functional abdominal pain. Meterial and methods: The study group comprised 58 patients (12 boys and 46 girls) from 9 to 17 years of age (av. 13.34±2.14 years) with functional abdominal pain, diagnosed according to the III Roman Criteria, and the control group of 58 healthy children in adequate age, of Bydgoszcz primary and secondary schools. The test method utilised The Anger Regulation and Expression Scale (SEG), The State-Trait Anxiety Inventory for Children (STAIC) and Me and My School Questionnaire. Analysing the results of scale SEG between the group of children with functional abdominal pain and healthy children, significant differences were observed in the scale of external anger (p=0.045). There were no differences between the group of children with functional abdominal pain and the comparative one in terms of Me and My School Inventory scale (p> 0.05). In the group of healthy adolescents, the average of motivation differed significantly from the result of the adolescents with functional abdominal pain (p=0.031). There were no differences between the group of children and adolescents with abdominal pain and the healthy ones in terms of the performance in STAIC scales (p>0.05). 1. Healthy children compared to children with functional abdominal pain more openly express negative emotions, such as anger and irritation, which can cause reduced tendency to the somatization of symptoms. 2. Symptoms of young people with functional abdominal pain intensify reluctance to fulfill school duties and heighten fear of school, depending on the speed of activation of the autonomic nervous system.

  5. Intra-abdominal hypertension and abdominal compartment syndrome in pediatrics. A review.

    PubMed

    Thabet, Farah Chedly; Ejike, Janeth Chiaka

    2017-10-01

    To consolidate pediatric intensivists' understanding of the pathophysiology, definition, incidence, monitoring, and management of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS); and to highlight the characteristics related to the pediatric population. This is a narrative review article that utilized a systematic search of the medical literature published in the English language between January 1990 and august 2016. Studies were identified by conducting a comprehensive search of Pub Med databases. Search terms included "intra-abdominal hypertension and child", "intra-abdominal hypertension and pediatrics", "abdominal compartment syndrome and child", and "abdominal compartment syndrome and pediatrics". Intra-abdominal hypertension and ACS are associated with a number of pathophysiological disturbances and increased morbidity and mortality. These conditions have been well described in critically ill adults. In children, the IAH and the ACS have a reported incidence of 13% and 0.6 to 10% respectively; they carry similar prognostic impact but are still under-diagnosed and under-recognized by pediatric health care providers. Intra-abdominal hypertension and ACS are conditions that are regularly encountered in critically ill children. They are associated with an increased morbidity and mortality. Early recognition, prevention and timely management of this critical condition are necessary to improve its outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Plain abdominal radiography in acute abdominal pain; past, present, and future

    PubMed Central

    Gans, Sarah L; Stoker, Jaap; Boermeester, Marja A

    2012-01-01

    Several studies have demonstrated that a diagnosis based solely on a patient’s medical history, physical examination, and laboratory tests is not reliable enough, despite the fact that these aspects are essential parts of the workup of a patient presenting with acute abdominal pain. Traditionally, imaging workup starts with abdominal radiography. However, numerous studies have demonstrated low sensitivity and accuracy for plain abdominal radiography in the evaluation of acute abdominal pain as well as various specific diseases such as perforated viscus, bowel obstruction, ingested foreign body, and ureteral stones. Computed tomography, and in particular computed tomography after negative ultrasonography, provides a better workup than plain abdominal radiography alone. The benefits of computed tomography lie in decision-making for management, planning of a surgical strategy, and possibly even avoidance of negative laparotomies. Based on abundant available evidence, major advances in diagnostic imaging, and changes in the management of certain diseases, we can conclude that there is no place for plain abdominal radiography in the workup of adult patients with acute abdominal pain presenting in the emergency department in current practice. PMID:22807640

  7. Ultra-wideband impedance sensor

    DOEpatents

    McEwan, Thomas E.

    1999-01-01

    The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near proximity of various materials such as metal, plastic, wood, petroleum products, and living tissue. It is much like a capacitance sensor, yet it is impervious to moisture. One broad application area is the general replacement of magnetic sensors, particularly where nonferrous materials need to be sensed. Another broad application area is sensing full/empty levels in tanks, vats and silos, e.g., a full/empty switch in water or petroleum tanks.

  8. Ultra-wideband impedance sensor

    DOEpatents

    McEwan, T.E.

    1999-03-16

    The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near proximity of various materials such as metal, plastic, wood, petroleum products, and living tissue. It is much like a capacitance sensor, yet it is impervious to moisture. One broad application area is the general replacement of magnetic sensors, particularly where nonferrous materials need to be sensed. Another broad application area is sensing full/empty levels in tanks, vats and silos, e.g., a full/empty switch in water or petroleum tanks. 2 figs.

  9. Effect of vegetation type on treatment performance and bioelectric production of constructed wetland modules combined with microbial fuel cell (CW-MFC) treating synthetic wastewater.

    PubMed

    Saz, Çağdaş; Türe, Cengiz; Türker, Onur Can; Yakar, Anıl

    2018-03-01

    An operation of microcosm-constructed wetland modules combined with microbial fuel cell device (CW-MFC) was assessed for wastewater treatment and bioelectric generation. One of the crucial aims of the present experiment is also to determine effect of vegetation on wastewater treatment process and bioelectric production in wetland matrix with microbial fuel cell. Accordingly, CW-MFC modules with vegetation had higher treatment efficiency compared to unplanted wetland module, and average COD, NH 4 + , and TP removal efficiency in vegetated wetland modules were ranged from 85 to 88%, 95 to 97%, and 95 to 97%, respectively. However, the highest NO 3 - removal (63%) was achieved by unplanted control module during the experiment period. The maximum average output voltage, power density, and Coulombic efficiency were obtained in wetland module vegetated with Typha angustifolia for 1.01 ± 0.14 V, 7.47 ± 13.7 mWatt/m 2 , and 8.28 ± 10.4%, respectively. The results suggest that the presence of Typha angustifolia vegetation in the CW-MFC matrix provides the benefits for treatment efficiency and bioelectric production; thus, it increases microbial activities which are responsible for biodegradation of organic compounds and catalyzed to electron flow from anode to cathode. Consequently, we suggest that engineers can use vegetated wetland matrix with Typha angustifolia in CW-MFC module in order to maximize treatment efficiency and bioelectric production.

  10. Abdominal Trauma Revisited.

    PubMed

    Feliciano, David V

    2017-11-01

    Although abdominal trauma has been described since antiquity, formal laparotomies for trauma were not performed until the 1800s. Even with the introduction of general anesthesia in the United States during the years 1842 to 1846, laparotomies for abdominal trauma were not performed during the Civil War. The first laparotomy for an abdominal gunshot wound in the United States was finally performed in New York City in 1884. An aggressive operative approach to all forms of abdominal trauma till the establishment of formal trauma centers (where data were analyzed) resulted in extraordinarily high rates of nontherapeutic laparotomies from the 1880s to the 1960s. More selective operative approaches to patients with abdominal stab wounds (1960s), blunt trauma (1970s), and gunshot wounds (1990s) were then developed. Current adjuncts to the diagnosis of abdominal trauma when serial physical examinations are unreliable include the following: 1) diagnostic peritoneal tap/lavage, 2) surgeon-performed ultrasound examination; 3) contrast-enhanced CT of the abdomen and pelvis; and 4) diagnostic laparoscopy. Operative techniques for injuries to the liver, spleen, duodenum, and pancreas have been refined considerably since World War II. These need to be emphasized repeatedly in an era when fewer patients undergo laparotomy for abdominal trauma. Finally, abdominal trauma damage control is a valuable operative approach in patients with physiologic exhaustion and multiple injuries.

  11. I/O impedance controller

    DOEpatents

    Ruesch, Rodney; Jenkins, Philip N.; Ma, Nan

    2004-03-09

    There is disclosed apparatus and apparatus for impedance control to provide for controlling the impedance of a communication circuit using an all-digital impedance control circuit wherein one or more control bits are used to tune the output impedance. In one example embodiment, the impedance control circuit is fabricated using circuit components found in a standard macro library of a computer aided design system. According to another example embodiment, there is provided a control for an output driver on an integrated circuit ("IC") device to provide for forming a resistor divider network with the output driver and a resistor off the IC device so that the divider network produces an output voltage, comparing the output voltage of the divider network with a reference voltage, and adjusting the output impedance of the output driver to attempt to match the output voltage of the divider network and the reference voltage. Also disclosed is over-sampling the divider network voltage, storing the results of the over sampling, repeating the over-sampling and storing, averaging the results of multiple over sampling operations, controlling the impedance with a plurality of bits forming a word, and updating the value of the word by only one least significant bit at a time.

  12. Continuous Negative Abdominal Pressure Reduces Ventilator-induced Lung Injury in a Porcine Model.

    PubMed

    Yoshida, Takeshi; Engelberts, Doreen; Otulakowski, Gail; Katira, Bhushan; Post, Martin; Ferguson, Niall D; Brochard, Laurent; Amato, Marcelo B P; Kavanagh, Brian P

    2018-04-27

    In supine patients with acute respiratory distress syndrome, the lung typically partitions into regions of dorsal atelectasis and ventral aeration ("baby lung"). Positive airway pressure is often used to recruit atelectasis, but often overinflates ventral (already aerated) regions. A novel approach to selective recruitment of dorsal atelectasis is by "continuous negative abdominal pressure." A randomized laboratory study was performed in anesthetized pigs. Lung injury was induced by surfactant lavage followed by 1 h of injurious mechanical ventilation. Randomization (five pigs in each group) was to positive end-expiratory pressure (PEEP) alone or PEEP with continuous negative abdominal pressure (-5 cm H2O via a plexiglass chamber enclosing hindlimbs, pelvis, and abdomen), followed by 4 h of injurious ventilation (high tidal volume, 20 ml/kg; low expiratory transpulmonary pressure, -3 cm H2O). The level of PEEP at the start was ≈7 (vs. ≈3) cm H2O in the PEEP (vs. PEEP plus continuous negative abdominal pressure) groups. Esophageal pressure, hemodynamics, and electrical impedance tomography were recorded, and injury determined by lung wet/dry weight ratio and interleukin-6 expression. All animals survived, but cardiac output was decreased in the PEEP group. Addition of continuous negative abdominal pressure to PEEP resulted in greater oxygenation (PaO2/fractional inspired oxygen 316 ± 134 vs. 80 ± 24 mmHg at 4 h, P = 0.005), compliance (14.2 ± 3.0 vs. 10.3 ± 2.2 ml/cm H2O, P = 0.049), and homogeneity of ventilation, with less pulmonary edema (≈10% less) and interleukin-6 expression (≈30% less). Continuous negative abdominal pressure added to PEEP reduces ventilator-induced lung injury in a pig model compared with PEEP alone, despite targeting identical expiratory transpulmonary pressure.

  13. Management of complex abdominal wall defects associated with penetrating abdominal trauma.

    PubMed

    Arul, G Suren; Sonka, B J; Lundy, J B; Rickard, R F; Jeffery, S L A

    2015-03-01

    The paradigm of Damage Control Surgery (DCS) has radically improved the management of abdominal trauma, but less well described are the options for managing the abdominal wall itself in an austere environment. This article describes a series of patients with complex abdominal wall problems managed at the UK-led Role 3 Medical Treatment Facility (MTF) in Camp Bastion, Afghanistan. Contemporaneous review of a series of patients with complex abdominal wall injuries who presented to the Role 3 MTF between July and November 2012. Five patients with penetrating abdominal trauma associated with significant damage to the abdominal wall were included. All patients were managed using DCS principles, leaving the abdominal wall open at the end of the first procedure. Subsequent management of the abdominal wall was determined by a multidisciplinary team of general and plastic surgeons, intensivists and specialist nurses. The principles of management identified included minimising tissue loss on initial laparotomy by joining adjacent wounds and marginal debridement of dead tissue; contraction of the abdominal wall was minimised by using topical negative pressure dressing and dermal-holding sutures. Definitive closure was timed to allow oedema to settle and sepsis to be controlled. Closure techniques include delayed primary closure with traction sutures, components separation, and mesh closure with skin grafting. A daily multidisciplinary team discussion was invaluable for optimal decision making regarding the most appropriate means of abdominal closure. Dermal-holding sutures were particularly useful in preventing myostatic contraction of the abdominal wall. A simple flow chart was developed to aid decision making in these patients. This flow chart may prove especially useful in a resource-limited environment in which returning months or years later for closure of a large ventral hernia may not be possible. Published by the BMJ Publishing Group Limited. For permission to use

  14. Enhanced sulfide removal and bioelectricity generation in microbial fuel cells with anodes modified by vertically oriented nanosheets.

    PubMed

    Yang, Meng; Zhong, Yuezhi; Zhang, Baogang; Shi, Jiaxin; Huang, Xueyang; Xing, Yi; Su, Lin; Liu, Huipeng; Borthwick, Alistair G L

    2018-01-31

    Anode materials and structures are of critical importance for microbial fuel cells (MFCs) recovering energy from toxic substrates. Carbon-fiber-felt anodes modified by layers of vertically oriented TiO 2 and Fe 2 O 3 nanosheets were applied in the present study. Enhanced sulfide removal efficiencies (both over 90%) were obtained after a 48-h operation, with maximum power densities improved by 1.53 and 1.36 folds compared with MFCs with raw carbon-fiber-felt anode. The modified anodes provided more active sites for microbial adhesion with increasing biomass densities. High-throughput 16S rRNA gene sequencing analysis also indicated the increase in microbial diversities. Bacteroidetes responsible for bioelectricity generation with Thiobacillus and Spirochaeta dominating sulfide removal were found in the MFCs with the modified anodes, with less anaerobic fermentative bacteria as Firmicutes appeared. This indicates that the proposed materials are competitive for applications of MFCs generating bioelectricity from toxic sulfide.

  15. The value of plain abdominal radiographs in management of abdominal emergencies in Luth.

    PubMed

    Ashindoitiang, J A; Atoyebi, A O; Arogundade, R A

    2008-01-01

    The plain abdominal x-ray is still the first imaging modality in diagnosis of acute abdomen. The aim of this study was to find the value of plain abdominal x-ray in the management of abdominal emergencies seen in Lagos university teaching hospital. The accurate diagnosis of the cause of acute abdominal pain is one of the most challenging undertakings in emergency medicine. This is due to overlapping of clinical presentation and non-specific findings of physical and even laboratory data of the multifarious causes. Plain abdominal radiography is one investigation that can be obtained readily and within a short period of time to help the physician arrive at a correct diagnosis The relevance of plain abdominal radiography was therefore evaluated in the management of abdominal emergencies seen in Lagos over a 12 month period (April 2002 to March 2003). A prospective study of 100 consecutively presenting patients with acute abdominal conditions treated by the general surgical unit of Lagos University Teaching Hospital was undertaken. All patients had supine and erect abdominal x-ray before any therapeutic intervention was undertaken. The diagnostic features of the plain films were compared with final diagnosis to determine the usefulness of the plain x-ray There were 54 males and 46 females (M:F 1.2:1). Twenty-four percent of the patients had intestinal obstruction, 20% perforated typhoid enteritis; gunshot injuries and generalized peritonitis each occurred in 13%, blunt abdominal trauma in 12%, while 8% and 10% had acute appendicitis and perforated peptic ulcer disease respectively. Of 100 patients studied, 54% had plain abdominal radiographs that showed positive diagnostic features. Plain abdominal radiograph showed high sensitivity in patients with intestinal obstruction 100% and perforated peptic ulcer 90% but was less sensitive in patients with perforated typhoid, acute appendicitis, and blunt abdominal trauma and generalized peritonitis. In conclusion, this study

  16. Evaluation of the levels of metalloproteinsase-2 in patients with abdominal aneurysm and abdominal hernias.

    PubMed

    Antoszewska, Magdalena

    2013-05-01

    Abdominal aortic aneurysms and abdominal hernias become an important health problems of our times. Abdominal aortic aneurysm and its rupture is one of the most dangerous fact in vascular surgery. There are some theories pointing to a multifactoral genesis of these kinds of diseases, all of them assume the attenuation of abdominal fascia and abdominal aortic wall. The density and continuity of these structures depend on collagen and elastic fibers structure. Reducing the strength of the fibers may be due to changes in the extracellular matrix (ECM) by the proteolytic enzymes-matrix metalloproteinases (MMPs) that degrade extracellular matrix proteins. These enzymes play an important role in the development of many disease: malignant tumors (colon, breast, lung, pancreas), cardiovascular disease (myocardial infarction, ischemia-reperfusion injury), connective tissue diseases (Ehler-Danlos Syndrome, Marfan's Syndrome), complications of diabetes (retinopathy, nephropathy). One of the most important is matrix metalloproteinase-2 (MMP-2). The aim of the study was an estimation of the MMP-2 blood levels in patients with abdominal aortic aneurysm and primary abdominal hernia, and in patients with only abdominal aortic aneurysm. The study involved 88 patients aged 42 to 89 years, including 75 men and 13 women. Patients were divided into two groups: patients with abdominal aortic aneurysm and primary abdominal hernia (45 persons, representing 51.1% of all group) and patients with only abdominal aortic aneurysm (43 persons, representing 48,9% of all group). It was a statistically significant increase in MMP-2 blood levels in patients with abdominal aortic aneurysm and primary abdominal hernia compared to patients with only abdominal aortic aneurysm. It was a statistically significant increase in the prevalence of POCHP in patients with only abdominal aortic aneurysm compared to patients with abdominal aortic aneurysm and primary abdominal hernia. Statistically significant

  17. [A commonly seen cause of abdominal pain: abdominal cutaneous nerve entrapment syndrome].

    PubMed

    Solmaz, Ilker; Talay, Mustafa; Tekindur, Şükrü; Kurt, Ercan

    2012-01-01

    Although abdominal cutaneous nerve entrapment syndrome (ACNES) is accepted as a rare condition, it is a syndrome that should be diagnosed more commonly when the clinical signs cannot explain the cause of abdominal pain. Abdominal pain is commonly considered by physicians to be based on intra-abdominal causes. Consequently, redundant tests and consultations are requested for these patients, and unnecessary surgical procedures may be applied. Patients with this type of pain are consulted to many clinics, and because their definitive diagnoses cannot be achieved, they are assessed as psychiatric patients. Actually, a common cause of abdominal wall pain is nerve entrapment on the lateral edge of the rectus abdominis muscle. In this paper, we would like to share information about the diagnosis and treatment of a patient who, prior to presenting to us, had applied to different clinics for chronic abdominal pain and had undergone many tests and consultations; abdominal surgery was eventually decided.

  18. MicroRNA Intercellular Transfer and Bioelectrical Regulation of Model Multicellular Ensembles by the Gap Junction Connectivity.

    PubMed

    Cervera, Javier; Meseguer, Salvador; Mafe, Salvador

    2017-08-17

    We have studied theoretically the microRNA (miRNA) intercellular transfer through voltage-gated gap junctions in terms of a biophysically grounded system of coupled differential equations. Instead of modeling a specific system, we use a general approach describing the interplay between the genetic mechanisms and the single-cell electric potentials. The dynamics of the multicellular ensemble are simulated under different conditions including spatially inhomogeneous transcription rates and local intercellular transfer of miRNAs. These processes result in spatiotemporal changes of miRNA, mRNA, and ion channel protein concentrations that eventually modify the bioelectrical states of small multicellular domains because of the ensemble average nature of the electrical potential. The simulations allow a qualitative understanding of the context-dependent nature of the effects observed when specific signaling molecules are transferred through gap junctions. The results suggest that an efficient miRNA intercellular transfer could permit the spatiotemporal control of small cellular domains by the conversion of single-cell genetic and bioelectric states into multicellular states regulated by the gap junction interconnectivity.

  19. In vitro metabolic engineering of bioelectricity generation by the complete oxidation of glucose.

    PubMed

    Zhu, Zhiguang; Zhang, Y-H Percival

    2017-01-01

    The direct generation of electricity from the most abundant renewable sugar, glucose, is an appealing alternative to the production of liquid biofuels and biohydrogen. However, enzyme-catalyzed bioelectricity generation from glucose suffers from low yields due to the incomplete oxidation of the six-carbon compound glucose via one or few enzymes. Here, we demonstrate a synthetic ATP- and CoA-free 12-enzyme pathway to implement the complete oxidation of glucose in vitro. This pathway is comprised of glucose phosphorylation via polyphosphate glucokinase, NADH generation catalyzed by glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH), electron transfer from NADH to the anode, and glucose 6-phosphate regeneration via the non-oxidative pentose phosphate pathway and gluconeogenesis. The faraday efficiency from glucose to electrons via this pathway was as high as 98.8%, suggesting the generation of nearly 24 electrons per molecule of glucose. The generated current density was greatly increased from 2.8 to 6.9mAcm -2 by replacing a low-activity G6PDH with a high-activity G6PDH and introducing a new enzyme, 6-phosphogluconolactonase, between G6PDH and 6PGDH. These results suggest the great potential of high-yield bioelectricity generation through in vitro metabolic engineering. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  20. A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

    NASA Astrophysics Data System (ADS)

    del Moral, A.; Azanza, María J.

    2015-03-01

    A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate ("frequency"), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca2+ Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD-CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD-CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B0 ≅0.2-15 mT) AC-MF of frequency fM=50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation.

  1. Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics.

    PubMed

    Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

    2016-02-04

    Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level.

  2. Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics

    PubMed Central

    Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

    2016-01-01

    Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level. PMID:26841954

  3. Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics

    NASA Astrophysics Data System (ADS)

    Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

    2016-02-01

    Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level.

  4. Method of Adjusting Acoustic Impedances for Impedance-Tunable Acoustic Segments

    NASA Technical Reports Server (NTRS)

    Jones, Kennie H (Inventor); Nark, Douglas M. (Inventor); Jones, Michael G. (Inventor); Parrott, Tony L. (Inventor); Lodding, Kenneth N. (Inventor)

    2012-01-01

    A method is provided for making localized decisions and taking localized actions to achieve a global solution. In an embodiment of the present invention, acoustic impedances for impedance-tunable acoustic segments are adjusted. A first acoustic segment through an N-th acoustic segment are defined. To start the process, the first acoustic segment is designated as a leader and a noise-reducing impedance is determined therefor. This is accomplished using (i) one or more metrics associated with the acoustic wave at the leader, and (ii) the metric(s) associated with the acoustic wave at the N-th acoustic segment. The leader, the N-th acoustic segment, and each of the acoustic segments exclusive of the leader and the N-th acoustic segment, are tuned to the noise-reducing impedance. The current leader is then excluded from subsequent processing steps. The designation of leader is then given one of the remaining acoustic segments, and the process is repeated for each of the acoustic segments through an (N-1)-th one of the acoustic segments.

  5. Focused abdominal sonography for trauma (FAST) in blunt paediatric abdominal trauma.

    PubMed

    Faruque, Ahmad Vaqas; Qazi, Saqib Hamid; Khan, Muhammad Arif Mateen; Akhtar, Wassem; Majeed, Amina

    2013-03-01

    To evaluate the role of focussed abdominal sonography for trauma in blunt paediatric abdominal trauma patients, and to see if the role of computed tomography scan could be limited to only those cases in which sonography was positive. The retrospective study covered 10 years, from January 1,2000 to December 31,2009, and was conducted at the Department of Radiology and Department of Emergency Medicine, Aga Khan University Hospital, Karachi. It comprised cases of 174 children from birth to 14 years who had presented with blunt abdominal trauma and had focussed abdominal sonography for trauma done at the hospital. The findings were correlated with computed tomography scan of the abdomen and clinical follow-up. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of focussed abdominal sonography for trauma were calculated for blunt abdominal trauma. SPSS 17 was used for statistical analysis. Of the total 174 cases, 31 (17.81%) were later confirmed by abdominal scan. Of these 31 children, sonography had been positive in 29 (93.54%) children. In 21 (67.74%) of the 31 children, sonograpy had been true positive; 8 (25%) (8/31) were false positive; and 2 (6%) (2/31) were false negative. There were 6 (19.3%) children in which sonography was positive and converted to laparotomy. There was no significant difference on account of gender (p>0.356). Focussed abdominal sonography for trauma in the study had sensitivity of 91%, specificity of 95%, positive predictive value of 73%, and negative predictive value of 73% with accuracy of 94%. All patients who had negative sonography were discharged later, and had no complication on clinical follow-up. Focussed abdominal sonography for trauma is a fairly reliable mode to assess blunt abdominal trauma in children. It is a useful tool to pick high-grade solid and hollow viscous injury. The results suggest that the role of computed tomography scan can be limited to those cases in which focussed

  6. OP-15 FEATURES OF AEROPHAGIA MEASURED WITH MULTICHANNEL PH-IMPEDANCE IN CHILDREN.

    PubMed

    Rybak, Anna; Gomez, Carlos Tutau; Lindley, Keith; Thapar, Nikhil; Mutalib, Mohamed

    2015-10-01

    Diagnosis of aerophagia is based on clinical symptoms and described in Rome III Criteria. The aim of this study was to estimate the normal and pathological values for air swallows measured with pH-impedance in children. We analysed features of air swallowing in pH-impedance for patients hospitalized in the Great Ormond Street Hospital in 2008-2014, with the clinical symptoms of aerophagia, who have met the Rome III Criteria. Children with pH-impedance performed due to other gastrointestinal conditions (GORD, Abdominal pain, food allergy and asthma) and had normal studies comprised the control group. The exclusion criteria were: neurological, metabolic or genetic disorders, previous oesophageal surgery including fundoplication, connective tissue disorders and studies lasting less than 16 hours in durationAll studies were re analysed manually, meals were excluded from analysis. Total number of air swallows (in upright and recumbent position); mixed swallows, gastric belching and supragastric belching were counted. The results were presented as total number of episodes and as median number of episodes per hour. Impedance recording of 10 patients (7 males) with clinical aerophagia and control group of10 children (7 males) were analysed. Mean age of patients was 10 years (4.5-13.5) and 7 years in control group (4.5-17 years). Mean (±SD) recording time for patients 21.3 hrs (±2.3) for control 21.2 hrs (±1.2).Total number of liquid reflux (mean ± SD) for patients 46.9 (±22.6), control 27.6 (±15.4) p = 0.028. The median of total air swallows per hour was 30.35 (IQR: 22.6 to 43.50) in patients with aerophagia and 7.33 (IQR: 5.43 to 9.9) in control group. There were significant differences in total number of air swallows, as well as in supragastric belches between the groups (p = 0.0001 and p = 0.001, respectively). Both, air swallows and gastric belches were significantly more often observed in boys (median for boys 20.92 and 1.06; for girls 7.20 and

  7. Image Reconstruction Under Contact Impedance Effect in Micro Electrical Impedance Tomography Sensors.

    PubMed

    Liu, Xiayi; Yao, Jiafeng; Zhao, Tong; Obara, Hiromichi; Cui, Yahui; Takei, Masahiro

    2018-06-01

    Contact impedance has an important effect on micro electrical impedance tomography (EIT) sensors compared to conventional macro sensors. In the present work, a complex contact impedance effect ratio ξ is defined to quantitatively evaluate the effect of the contact impedance on the accuracy of the reconstructed images by micro EIT. Quality of the reconstructed image under various ξ is estimated by the phantom simulation to find the optimum algorithm. The generalized vector sampled pattern matching (GVSPM) method reveals the best image quality and the best tolerance to ξ. Moreover, the images of yeast cells sedimentary distribution in a multilayered microchannel are reconstructed by the GVSPM method under various mean magnitudes of contact impedance effect ratio |ξ|. The result shows that the best image quality that has the smallest voltage error U E = 0.581 is achieved with measurement frequency f = 1 MHz and mean magnitude |ξ| = 26. In addition, the reconstructed images of cells distribution become improper while f < 10 kHz and mean value of |ξ| > 2400.

  8. Child with Abdominal Pain.

    PubMed

    Iyer, Rajalakshmi; Nallasamy, Karthi

    2018-01-01

    Abdominal pain is one of the common symptoms reported by children in urgent care clinics. While most children tend to have self-limiting conditions, the treating pediatrician should watch out for underlying serious causes like intestinal obstruction and perforation peritonitis, which require immediate referral to an emergency department (ED). Abdominal pain may be secondary to surgical or non-surgical causes, and will differ as per the age of the child. The common etiologies for abdominal pain presenting to an urgent care clinic are acute gastro-enteritis, constipation and functional abdominal pain; however, a variety of extra-abdominal conditions may also present as abdominal pain. Meticulous history taking and physical examination are the best tools for diagnosis, while investigations have a limited role in treating benign etiologies.

  9. Abdominal wall fat pad biopsy

    MedlinePlus

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... most common method of taking an abdominal wall fat pad biopsy . The health care provider cleans the ...

  10. Impeded Dark Matter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kopp, Joachim; Liu, Jia; Slatyer, Tracy

    Here, we consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario \\Impeded Dark Matter". We also demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may evenmore » be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. Furthermore, for positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.« less

  11. Impeded Dark Matter

    DOE PAGES

    Kopp, Joachim; Liu, Jia; Slatyer, Tracy; ...

    2016-12-12

    Here, we consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario \\Impeded Dark Matter". We also demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may evenmore » be kinematically forbidden, making this scenario almost insensitive to constraints from the cosmic microwave background and from observations of dwarf galaxies. Accordingly, it may be possible for Impeded Dark Matter to yield observable signals in clusters or the Galactic center, with no corresponding signal in dwarfs. Furthermore, for positive mass splitting, we show that the annihilation cross-section is suppressed by the small mass splitting, which helps light dark matter to survive increasingly stringent constraints from indirect searches. As specific realizations for Impeded Dark Matter, we introduce a model of vector dark matter from a hidden SU(2) sector, and a composite dark matter scenario based on a QCD-like dark sector.« less

  12. Viability of a Bioelectrical Signal Acquisition System Energized by Cellphone with NFC.

    PubMed

    Kay, Marcel Seiji; Iaione, Fábio

    2015-01-01

    Currently, smartphones are used in various systems in the medical field due to the presence of various features, notably Near Field Communication (NFC). NFC utilizes communication technology and an energy supply based on electromagnetic induction. One of the most common medical tests is the electrocardiogram (ECG), through which various heart diseases can be diagnosed. The objective of this study is to evaluate the feasibility of providing power to a bioelectrical signal acquisition module using a mobile phone with NFC. After testing it was indicated that it is possible to construct a passive module to acquire ECG signals using NFC mobile phone.

  13. Enhanced Shewanella biofilm promotes bioelectricity generation.

    PubMed

    Liu, Ting; Yu, Yang-Yang; Deng, Xiao-Peng; Ng, Chun Kiat; Cao, Bin; Wang, Jing-Yuan; Rice, Scott A; Kjelleberg, Staffan; Song, Hao

    2015-10-01

    Electroactive biofilms play essential roles in determining the power output of microbial fuel cells (MFCs). To engineer the electroactive biofilm formation of Shewanella oneidensis MR-1, a model exoelectrogen, we herein heterologously overexpressed a c-di-GMP biosynthesis gene ydeH in S. oneidensis MR-1, constructing a mutant strain in which the expression of ydeH is under the control of IPTG-inducible promoter, and a strain in which ydeH is under the control of a constitutive promoter. Such engineered Shewanella strains had significantly enhanced biofilm formation and bioelectricity generation. The MFCs inoculated with these engineered strains accomplished a maximum power density of 167.6 ± 3.6 mW/m(2) , which was ∼ 2.8 times of that achieved by the wild-type MR-1 (61.0 ± 1.9 mW/m(2) ). In addition, the engineered strains in the bioelectrochemical system at poised potential of 0.2 V vs. saturated calomel electrode (SCE) generated a stable current density of 1100 mA/m(2) , ∼ 3.4 times of that by wild-type MR-1 (320 mA/m(2) ). © 2015 Wiley Periodicals, Inc.

  14. Don't Forget the Abdominal Wall: Imaging Spectrum of Abdominal Wall Injuries after Nonpenetrating Trauma.

    PubMed

    Matalon, Shanna A; Askari, Reza; Gates, Jonathan D; Patel, Ketan; Sodickson, Aaron D; Khurana, Bharti

    2017-01-01

    Abdominal wall injuries occur in nearly one of 10 patients coming to the emergency department after nonpenetrating trauma. Injuries range from minor, such as abdominal wall contusion, to severe, such as abdominal wall rupture with evisceration of abdominal contents. Examples of specific injuries that can be detected at cross-sectional imaging include abdominal muscle strain, tear, or hematoma, including rectus sheath hematoma (RSH); traumatic abdominal wall hernia (TAWH); and Morel-Lavallée lesion (MLL) (closed degloving injury). These injuries are often overlooked clinically because of (a) a lack of findings at physical examination or (b) distraction by more-severe associated injuries. However, these injuries are important to detect because they are highly associated with potentially grave visceral and vascular injuries, such as aortic injury, and because their detection can lead to the diagnosis of these more clinically important grave traumatic injuries. Failure to make a timely diagnosis can result in delayed complications, such as bowel hernia with potential for obstruction or strangulation, or misdiagnosis of an abdominal wall neoplasm. Groin injuries, such as athletic pubalgia, and inferior costochondral injuries should also be considered in patients with abdominal pain after nonpenetrating trauma, because these conditions may manifest with referred abdominal pain and are often included within the field of view at cross-sectional abdominal imaging. Radiologists must recognize and report acute abdominal wall injuries and their associated intra-abdominal pathologic conditions to allow appropriate and timely treatment. © RSNA, 2017.

  15. Correlation between intra-abdominal pressure and pulmonary volumes after superior and inferior abdominal surgery.

    PubMed

    Cleva, Roberto de; Assumpção, Marianna Siqueira de; Sasaya, Flavia; Chaves, Natalia Zuniaga; Santo, Marco Aurelio; Fló, Claudia; Lunardi, Adriana C; Jacob Filho, Wilson

    2014-07-01

    Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC) to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior). We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique. The mean age of the patients was 56 ± 13 years, and 41.6% 25 were female; 50 patients (83.3%) had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior). The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6 ± 0.6 L) and FVC (2.0 ± 0.7 L) with maintenance of FEV1/FVC of 0.8 ± 0.2 in both groups. The maximum intra-abdominal pressure values were similar (p=0.59) for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed. Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery.

  16. Cutoff points of waist circumference and trunk and visceral fat for identifying children with elevated inflammation markers and adipokines: The Healthy Growth Study.

    PubMed

    Karatzi, Kalliopi; Moschonis, George; Polychronopoulou, Maria Christina; Chrousos, George P; Lionis, Christos; Manios, Yannis

    2016-10-01

    Excessive fat storage is accompanied by several comorbidities in children and early identification of elevated abdominal fat may be extremely valuable in early prevention of cardiometabolic risk. The aim of the present study was to establish cutoff points for waist circumference trunk and visceral fat, thus identifying increased likelihood of elevated inflammatory markers and adipokines in children. A representative sample of schoolchildren (aged 9-13 y) participated in a cross-sectional epidemiologic study conducted in Greece. Anthropometric and physical examination data, biochemical indices, and socioeconomic information (collected from parents) were assessed for all children. Central adiposity markers (trunk and visceral fat) were collected with bioelectrical impedance analysis for 999 children. Specific cutoff values of abdominal adiposity indices indicating increased likelihood of elevated levels of C-reactive protein, interleukin-6, and leptin and decreased levels of adiponectin were calculated by sex. These cutoff values were; 67.5 cm for boys and 69.5 cm for girls for waist circumference, 17.75% for boys and 22.65% for girls for trunk fat mass percentage, and 3.95 for boys and 2.55 for girls for visceral fat rating. To our knowledge, this is the first study to establish simple cutoff points for abdominal adiposity indices identifying children at high risk for elevated inflammatory markers and decreased adipokine levels. Future studies are essential to confirm these findings. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Chronic Abdominal Wall Pain.

    PubMed

    Koop, Herbert; Koprdova, Simona; Schürmann, Christine

    2016-01-29

    Chronic abdominal wall pain is a poorly recognized clinical problem despite being an important element in the differential diagnosis of abdominal pain. This review is based on pertinent articles that were retrieved by a selective search in PubMed and EMBASE employing the terms "abdominal wall pain" and "cutaneous nerve entrapment syndrome," as well as on the authors' clinical experience. In 2% to 3% of patients with chronic abdominal pain, the pain arises from the abdominal wall; in patients with previously diagnosed chronic abdominal pain who have no demonstrable pathological abnormality, this likelihood can rise as high as 30% . There have only been a small number of clinical trials of treatment for this condition. The diagnosis is made on clinical grounds, with the aid of Carnett's test. The characteristic clinical feature is strictly localized pain in the anterior abdominal wall, which is often mischaracterized as a "functional" complaint. In one study, injection of local anesthesia combined with steroids into the painful area was found to relieve pain for 4 weeks in 95% of patients. The injection of lidocaine alone brought about improvement in 83-91% of patients. Long-term pain relief ensued after a single lidocaine injection in 20-30% of patients, after repeated injections in 40-50% , and after combined lidocaine and steroid injections in up to 80% . Pain that persists despite these treatments can be treated with surgery (neurectomy). Chronic abdominal wall pain is easily diagnosed on physical examination and can often be rapidly treated. Any physician treating patients with abdominal pain should be aware of this condition. Further comparative treatment trials will be needed before a validated treatment algorithm can be established.

  18. Fossilized bioelectric wire - the trace fossil Trichichnus

    NASA Astrophysics Data System (ADS)

    Kędzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

    2014-12-01

    The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the interface oxic - anoxic zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that produced by modern large, mat-forming, sulphide-oxidizing bacteria, belonging mostly to Trichichnus-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized "electric wire".

  19. Fossilized bioelectric wire - the trace fossil Trichichnus

    NASA Astrophysics Data System (ADS)

    Kędzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

    2015-04-01

    The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the oxic-anoxic interface zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus, formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that it is produced by modern large, mat-forming, sulfide-oxidizing bacteria, belonging mostly to Thioploca-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized "electric wire".

  20. [The bioelectric activity of the brain in dyscirculatory encephalopathy and arterial hypertension developed in the Chernobyl nuclear disaster liquidators].

    PubMed

    Podsonnaia, I V; Efremushkin, G G; Zhelobetskaia, E D

    2012-01-01

    The long-term effects of the ionizing radiation on the bioelectric brain activity in the Chernobyl nuclear disaster liquidators with discirculatory encephalopathy and arterial hypertension were studied. We examined 195 male patients, aged from 30 to 65 years, with the clinical presentations of discirculatory encephalopathy, using electroencephalography: 105 patients were liquidators of the Chernobyl nuclear disaster (the main group) and 90 patients had no radiation anamnesis (the comparison group). It has been found that the development of discirculatory encephalopathy in liquidators of the Chernobyl nuclear disaster is mainly associated with the dysfunction of diencephalic and cortical structures. The specificity of the neurofunctional brain abnormalities in liquidators with discirculatory encephalopathy is characterized by the predominance of the low-amplitude and low-frequency alpha-activity or by the lack of alpha-rhythm and by its substitution for the high-frequency beta-rhythm with the presence of theta- and delta-activity and by the more significant flatness of the alpha-rhythm zonation. The presence of the radiation factor in the past history is correlated with the failure of the bioelectric brain activity in the alpha band (r=0.42) that increases risk of abnormal changes by a factor of 10 (p<0.001). The liquidators with arterial hypertension are characterized by the more frequent occurrence of the asymmetry of the recorded bioelectric potentials between the similar hemispheric areas, by the more significant difference in the external stimulus response of the brain (functional tests). The results indicate the more complicated and diffuse lesion of the brain in the liquidators of the Chernobyl nuclear disaster in the post-radiation period during the development of discirculatory encephalopathy and arterial hypertension.

  1. The interplay between genetic and bioelectrical signaling permits a spatial regionalisation of membrane potentials in model multicellular ensembles

    PubMed Central

    Cervera, Javier; Meseguer, Salvador; Mafe, Salvador

    2016-01-01

    The single cell-centred approach emphasises ion channels as specific proteins that determine individual properties, disregarding their contribution to multicellular outcomes. We simulate the interplay between genetic and bioelectrical signals in non-excitable cells from the local single-cell level to the long range multicellular ensemble. The single-cell genetic regulation is based on mean-field kinetic equations involving the mRNA and protein concentrations. The transcription rate factor is assumed to depend on the absolute value of the cell potential, which is dictated by the voltage-gated cell ion channels and the intercellular gap junctions. The interplay between genetic and electrical signals may allow translating single-cell states into multicellular states which provide spatio-temporal information. The model results have clear implications for biological processes: (i) bioelectric signals can override slightly different genetic pre-patterns; (ii) ensembles of cells initially at the same potential can undergo an electrical regionalisation because of persistent genetic differences between adjacent spatial regions; and (iii) shifts in the normal cell electrical balance could trigger significant changes in the genetic regulation. PMID:27731412

  2. The interplay between genetic and bioelectrical signaling permits a spatial regionalisation of membrane potentials in model multicellular ensembles.

    PubMed

    Cervera, Javier; Meseguer, Salvador; Mafe, Salvador

    2016-10-12

    The single cell-centred approach emphasises ion channels as specific proteins that determine individual properties, disregarding their contribution to multicellular outcomes. We simulate the interplay between genetic and bioelectrical signals in non-excitable cells from the local single-cell level to the long range multicellular ensemble. The single-cell genetic regulation is based on mean-field kinetic equations involving the mRNA and protein concentrations. The transcription rate factor is assumed to depend on the absolute value of the cell potential, which is dictated by the voltage-gated cell ion channels and the intercellular gap junctions. The interplay between genetic and electrical signals may allow translating single-cell states into multicellular states which provide spatio-temporal information. The model results have clear implications for biological processes: (i) bioelectric signals can override slightly different genetic pre-patterns; (ii) ensembles of cells initially at the same potential can undergo an electrical regionalisation because of persistent genetic differences between adjacent spatial regions; and (iii) shifts in the normal cell electrical balance could trigger significant changes in the genetic regulation.

  3. Optically stimulated differential impedance spectroscopy

    DOEpatents

    Maxey, Lonnie C; Parks, II, James E; Lewis, Sr., Samuel A; Partridge, Jr., William P

    2014-02-18

    Methods and apparatuses for evaluating a material are described. Embodiments typically involve use of an impedance measurement sensor to measure the impedance of a sample of the material under at least two different states of illumination. The states of illumination may include (a) substantially no optical stimulation, (b) substantial optical stimulation, (c) optical stimulation at a first wavelength of light, (d) optical stimulation at a second wavelength of light, (e) a first level of light intensity, and (f) a second level of light intensity. Typically a difference in impedance between the impedance of the sample at the two states of illumination is measured to determine a characteristic of the material.

  4. Retrospective comparison of abdominal ultrasonography and radiography in the investigation of feline abdominal disease

    PubMed Central

    Won, Wylen Wade; Sharma, Ajay; Wu, Wenbo

    2015-01-01

    Abdominal radiography and ultrasonography are commonly used as part of the initial diagnostic plan for cats with nonspecific signs of abdominal disease. This retrospective study compared the clinical usefulness of abdominal radiography and ultrasonography in 105 feline patients with signs of abdominal disease. The final diagnosis was determined more commonly with ultrasonography (59%) compared to radiography (25.7%). Ultrasonography was also able to provide additional clinically relevant information in 76% of cases, and changed or refined the diagnosis in 47% of cases. Based on these findings, ultrasonography may be sufficient as an initial diagnostic test for the investigation of feline abdominal disease. PMID:26483582

  5. The Tribolium homeotic gene Abdominal is homologous to abdominal-A of the Drosophila bithorax complex

    NASA Technical Reports Server (NTRS)

    Stuart, J. J.; Brown, S. J.; Beeman, R. W.; Denell, R. E.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    The Abdominal gene is a member of the single homeotic complex of the beetle, Tribolium castaneum. An integrated developmental genetic and molecular analysis shows that Abdominal is homologous to the abdominal-A gene of the bithorax complex of Drosophila. abdominal-A mutant embryos display strong homeotic transformations of the anterior abdomen (parasegments 7-9) to PS6, whereas developmental commitments in the posterior abdomen depend primarily on Abdominal-B. In beetle embryos lacking Abdominal function, parasegments throughout the abdomen are transformed to PS6. This observation demonstrates the general functional significance of parasegmental expression among insects and shows that the control of determinative decisions in the posterior abdomen by homeotic selector genes has undergone considerable evolutionary modification.

  6. The Tribolium homeotic gene Abdominal is homologous to abdominal-A of the Drosophila bithorax complex.

    PubMed

    Stuart, J J; Brown, S J; Beeman, R W; Denell, R E

    1993-01-01

    The Abdominal gene is a member of the single homeotic complex of the beetle, Tribolium castaneum. An integrated developmental genetic and molecular analysis shows that Abdominal is homologous to the abdominal-A gene of the bithorax complex of Drosophila. abdominal-A mutant embryos display strong homeotic transformations of the anterior abdomen (parasegments 7-9) to PS6, whereas developmental commitments in the posterior abdomen depend primarily on Abdominal-B. In beetle embryos lacking Abdominal function, parasegments throughout the abdomen are transformed to PS6. This observation demonstrates the general functional significance of parasegmental expression among insects and shows that the control of determinative decisions in the posterior abdomen by homeotic selector genes has undergone considerable evolutionary modification.

  7. [Differential diagnosis of abdominal pain].

    PubMed

    Frei, Pascal

    2015-09-02

    Despite the frequency of functional abdominal pain, potentially dangerous causes of abdominal pain need to be excluded. Medical history and clinical examination must focus on red flags and signs for imflammatory or malignant diseases. See the patient twice in the case of severe and acute abdominal pain if lab parameters or radiological examinations are normal. Avoid repeated and useless X-ray exposure whenever possible. In the case of subacute or chronic abdominal pain, lab tests such as fecal calprotectin, helicobacter stool antigen and serological tests for celiac disease are very useful. Elderly patients may show atypical or missing clinical signs. Take care of red herrings and be skeptical whether your initial diagnosis is really correct. Abdominal pain can frequently be an abdominal wall pain.

  8. Electromagnetic scattering by impedance structures

    NASA Technical Reports Server (NTRS)

    Balanis, Constantine A.; Griesser, Timothy

    1987-01-01

    The scattering of electromagnetic waves from impedance structures is investigated, and current work on antenna pattern calculation is presented. A general algorithm for determining radiation patterns from antennas mounted near or on polygonal plates is presented. These plates are assumed to be of a material which satisfies the Leontovich (or surface impedance) boundary condition. Calculated patterns including reflection and diffraction terms are presented for numerious geometries, and refinements are included for antennas mounted directly on impedance surfaces. For the case of a monopole mounted on a surface impedance ground plane, computed patterns are compared with experimental measurements. This work in antenna pattern prediction forms the basis of understanding of the complex scattering mechanisms from impedance surfaces. It provides the foundation for the analysis of backscattering patterns which, in general, are more problematic than calculation of antenna patterns. Further proposed study of related topics, including surface waves, corner diffractions, and multiple diffractions, is outlined.

  9. 21 CFR 870.2770 - Impedance plethysmograph.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Impedance plethysmograph. 870.2770 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2770 Impedance plethysmograph. (a) Identification. An impedance plethysmograph is a device used to estimate peripheral blood...

  10. Electro-optic electrodes based on Lithium Niobate Mach Zhender Interferometer Modulators for wearable bioelectric activity recording

    NASA Astrophysics Data System (ADS)

    Fernandes, Mariana S.; Correia, José H.; Mendes, Paulo M.

    2011-05-01

    Wearable devices are used to record several physiological signals, providing unobtrusive and continuous monitoring. A main challenge in these systems is to develop new recording sensors, specially envisioning bioelectric activity detection. Available devices are difficult to integrate, mainly due to the amount of electrical wires and components needed. This work proposes a fiber-optic based device, which basis of operation relies on the electro-optic effect. A Lithium Niobate (LiBnO3) Mach-Zehnder Interferometer (MZI) modulator is used as the core sensing component, followed by a signal conversion and processing stage. Tests were performed in order to validate the proposed acquisition system in terms of signal amplification and quality, stability and frequency response. A light source with a wavelength operation of 1530- 1565 nm was used. The modulated intensity is amplified and converted to an output voltage with a high transimpedance gain. The filtering and electric amplification included a 50Hz notch filter, a bandpass filter with a -3 dB bandwidth from 0.50 to 35 Hz. The obtained system performance on key elements such as sensitivity, frequency content, and signal quality, have shown that the proposed acquisition system allows the development of new wearable bioelectric monitoring solutions based on optical technologies.

  11. Superconducting fault current-limiter with variable shunt impedance

    DOEpatents

    Llambes, Juan Carlos H; Xiong, Xuming

    2013-11-19

    A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

  12. Chronic abdominal wall pain and ultrasound-guided abdominal cutaneous nerve infiltration: a case series.

    PubMed

    Kanakarajan, Saravanakumar; High, Kristina; Nagaraja, Ravi

    2011-03-01

    Chronic abdominal wall pain occurs in about 10-30% of patients presenting with chronic abdominal pain. Entrapment of abdominal cutaneous nerves at the lateral border of the rectus abdominis muscle has been attributed as a cause of abdominal wall pain. We report our experience of treating such patients using ultrasound-guided abdominal cutaneous nerve infiltration. We conducted a retrospective audit of abdominal cutaneous nerve infiltration performed in the period between September 2008 to August 2009 in our center. All patients had received local anesthetic and steroid injection under ultrasound guidance. The response to the infiltration was evaluated in the post-procedure telephone review as well as in the follow-up clinic. Brief pain inventory (BPI) and numerical rating scale pain scores were collated from two points: the initial outpatient clinic and the follow up clinic up to 5 months following the injection. Nine patients had abdominal cutaneous nerve injections under ultrasound guidance in the period under review. Six patients reported 50% pain relief or more (responders) while three patients did not. Pain and BPI scores showed a decreasing trend in responders. The median duration of follow-up was 12 weeks. Ultrasound can reliably be used for infiltration of the abdominal cutaneous nerves. This will improve the safety as well as diagnostic utility of the procedure. Wiley Periodicals, Inc.

  13. Role of the Functional State of the Hypothalamus in Bioelectric Reactions of the Cerebral Cortex to Radiation,

    DTIC Science & Technology

    The effect of subjection of the hypothalamus to electrocoagulation in the area of the mamillary bodies on the bioelectric activity and reactivity of...the cerebral cortex exposed to radiation was studied. Rabbits were irradiated on the 10th day after electrocoagulation . Immediately after... electrocoagulation , a decline in the excitability and functional activity of cortical neurons in the posterior section of the cortex and a decrease in the

  14. Epipremnum aureum and Dracaena braunii as indoor plants for enhanced bio-electricity generation in a plant microbial fuel cell with electrochemically modified carbon fiber brush anode.

    PubMed

    Sarma, Pranab Jyoti; Mohanty, Kaustubha

    2018-04-13

    In this study, two different unexploited indoor plants, Epipremnum aureum and Dracaena braunii were used to produce clean and sustainable bio-electricity in a plant microbial fuel cell (PMFC). Acid modified carbon fiber brush electrodes as well as bare electrodes were used in both the PMFCs. A bentonite based clay membrane was successfully integrated in the PMFCs. Maximum performance of E. aureum was 620 mV which was 188 mV higher potential than D. braunii. The bio-electricity generation using modified electrode was 154 mV higher than the bare carbon fiber, probably due to the effective bacterial attachment to the carbon fiber owing to hydrogen bonding. Maximum power output of 15.38 mW/m 2 was obtained by E. aureum with an internal resistance of 200 Ω. Higher biomass yield was also obtained in case of E. aureum during 60 days of experiment, which may correlate with the higher bio-electricity generation than D. braunii. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Microfabricated AC impedance sensor

    DOEpatents

    Krulevitch, Peter; Ackler, Harold D.; Becker, Frederick; Boser, Bernhard E.; Eldredge, Adam B.; Fuller, Christopher K.; Gascoyne, Peter R. C.; Hamilton, Julie K.; Swierkowski, Stefan P.; Wang, Xiao-Bo

    2002-01-01

    A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and with electrodes patterned on both substrates, and 2) electrical circuits that connect to the electrodes on the microfluidic chip and detect signals associated with particles traveling down the microchannels. These circuits enable multiple AC impedance measurements of individual particles at high throughput rates with sufficient resolution to identify different particle and cell types as appropriate for environmental detection and clinical diagnostic applications.

  16. Impedance of a nanoantenna

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Greffet, Jean-Jacques; Laroche, Marine; Marquier, Francois

    2009-10-07

    We introduce a generalized definition of the impedance of a nanoantenna that can be applied to any system. We also introduce a definition of the impedance of a two level system. Using this framework, we establish a link between the electrical engineering and the quantum optics picture of light emission.

  17. Home environmental consequences of commute travel impedance.

    PubMed

    Novaco, R W; Kliewer, W; Broquet, A

    1991-12-01

    The physical and perceptual dimensions of commuting travel impedance were again found to have stressful consequences in a study of 99 employees of two companies. This quasi-experimental replication study, which focuses here on home environment consequences, investigated the effects of physical impedance and subjective impedance on multivariate measures of residential satisfaction and personal affect in the home. Both sets of residential outcome measures were significantly related to the two impedance dimensions. As predicted, gender was a significant moderator of physical impedance effects. Women commuting on high physical impedance routes were most negatively affected. Previously found subjective impedance effects on negative home mood, regardless of gender, were strongly replicated with several methods and were buttressed by convergent results with objective indices. The theoretical conjecture that subjective impedance mediates the stress effects of physical impedance was supported by the personal affect cluster but only for one variable in the residential satisfaction cluster. Traffic congestion has increased in metropolitan areas nationwide, and commuters, families, and organizations are absorbing associated hidden costs. The results are reviewed in terms of our ecological model, and the moderating effects of gender are discussed in terms of choice and role constraints.

  18. 21 CFR 870.2750 - Impedance phlebograph.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Impedance phlebograph. 870.2750 Section 870.2750...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2750 Impedance phlebograph. (a) Identification. An impedance phlebograph is a device used to provide a visual display of the...

  19. Integrating microbial fuel cells with anaerobic acidification and forward osmosis membrane for enhancing bio-electricity and water recovery from low-strength wastewater.

    PubMed

    Liu, Jinmeng; Wang, Xinhua; Wang, Zhiwei; Lu, Yuqin; Li, Xiufen; Ren, Yueping

    2017-03-01

    Microbial fuel cells (MFCs) and forward osmosis (FO) are two emerging technologies with great potential for energy-efficient wastewater treatment. In this study, anaerobic acidification and FO membrane were simultaneously integrated into an air-cathode MFC (AAFO-MFC) for enhancing bio-electricity and water recovery from low-strength wastewater. During a long-term operation of approximately 40 days, the AAFO-MFC system achieved a continuous and relatively stable power generation, and the maximum power density reached 4.38 W/m 3 . The higher bio-electricity production in the AAFO-MFC system was mainly due to the accumulation of ethanol resulted from anaerobic acidification process and the rejection of FO membrane. In addition, a proper salinity environment in the system controlled by the addition of MF membrane enhanced the electricity production. Furthermore, the AAFO-MFC system produced a high quality effluent, with the removal rates of organic matters and total phosphorus of more than 97%. However, the nitrogen removal was limited for the lower rejection of FO membrane. The combined biofouling and inorganic fouling were responsible for the lower water flux of FO membrane, and the Desulfuromonas sp. utilized the ethanol for bio-electricity production was observed in the anode. These results substantially improve the prospects for simultaneous wastewater treatment and energy recovery, and further studies are needed to optimize the system integration and operating parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Abdominal elephantiasis: a case report.

    PubMed

    Hanna, Dominique; Cloutier, Richard; Lapointe, Roch; Desgagné, Antoine

    2004-01-01

    Elephantiasis is a well-known condition in dermatology usually affecting the legs and external genitalia. It is characterized by chronic inflammation and obstruction of the lymphatic channels and by hypertrophy of the skin and subcutaneous tissues. The etiology is either idiopathic or caused by a variety of conditions such as chronic filarial disease, leprosy, leishmaniasis, and chronic recurrent cellulites. Elephantiasis of the abdominal wall is very rare. A complete review of the English and French literature showed only two cases reported in 1966 and 1973, respectively. We report a third case of abdominal elephantiasis and we briefly review this entity. We present the case of a 51-year-old woman who had progressively developed an enormous pediculated abdominal mass hanging down her knees. The skin was thickened, hyperpigmented, and fissured. She had a history of multiple abdominal cellulites. She underwent an abdominal lipectomy. Histopathology of the specimen confirmed the diagnosis of abdominal elephantiasis. Abdominal elephantiasis is a rare disease that represents end-stage failure of lymph drainage. Lipectomy should be considered in the management of this condition.

  1. In vitro comparison of intra-abdominal hypertension development after different temporary abdominal closure techniques.

    PubMed

    Benninger, Emanuel; Labler, Ludwig; Seifert, Burkhardt; Trentz, Otmar; Menger, Michael D; Meier, Christoph

    2008-01-01

    To compare volume reserve capacity (VRC) and development of intra-abdominal hypertension after different in vitro temporary abdominal closure (TAC) techniques. A model of the abdomen was designed. The abdominal wall was simulated with polychloroprene, a synthetic rubber compound. A lentil-shaped defect of 150 cm(2) was cut into the anterior aspect of the abdominal wall. TAC of this defect was performed by a zipper system (ZS), a bag silo closure (BSC), or a vacuum assisted closure (VAC) with subatmospheric pressures ranging from 0- to 200 mmHg. The model with intact abdominal wall served as reference. The model was filled with water to baseline level. The intra-abdominal pressure was increased in 2 mmHg steps from baseline level (6 mmHg) to 40 mmHg by adding volume to the system according to a standardized protocol. VRC with corresponding intra-abdominal pressure were analyzed and compared for the different TAC techniques. VRC was the highest after BSC at all pressure levels studied (P < 0.05). VAC and ZS resulted in significantly lower VRC compared with BSC and reference (P < 0.05). The magnitude of negative pressure on the VAC did not significantly influence the VRC. In the present in vitro model, BSC demonstrated the highest VRC of all evaluated TAC techniques. Different levels of subatmospheric pressures applied to the VAC did not affect VRC. The results for ZS and VAC indicate that these TAC techniques may increase the risk for recurrent intra-abdominal hypertension and should therefore not be used in high-risk patients during the initial phase after abdominal decompression.

  2. Ionospheric effects to antenna impedance

    NASA Technical Reports Server (NTRS)

    Bethke, K. H.

    1986-01-01

    The reciprocity between high power satellite antennas and the surrounding plasma are examined. The relevant plasma states for antenna impedance calculations are presented and plasma models, and hydrodynamic and kinetic theory, are discussed. A theory from which a variation in antenna impedance with regard to the radiated power can be calculated for a frequency range well above the plasma resonance frequency is give. The theory can include photo and secondary emission effects in antenna impedance calculations.

  3. Abdominal hernias: Radiological features

    PubMed Central

    Lassandro, Francesco; Iasiello, Francesca; Pizza, Nunzia Luisa; Valente, Tullio; Stefano, Maria Luisa Mangoni di Santo; Grassi, Roberto; Muto, Roberto

    2011-01-01

    Abdominal wall hernias are common diseases of the abdomen with a global incidence approximately 4%-5%. They are distinguished in external, diaphragmatic and internal hernias on the basis of their localisation. Groin hernias are the most common with a prevalence of 75%, followed by femoral (15%) and umbilical (8%). There is a higher prevalence in males (M:F, 8:1). Diagnosis is usually made on physical examination. However, clinical diagnosis may be difficult, especially in patients with obesity, pain or abdominal wall scarring. In these cases, abdominal imaging may be the first clue to the correct diagnosis and to confirm suspected complications. Different imaging modalities are used: conventional radiographs or barium studies, ultrasonography and Computed Tomography. Imaging modalities can aid in the differential diagnosis of palpable abdominal wall masses and can help to define hernial contents such as fatty tissue, bowel, other organs or fluid. This work focuses on the main radiological findings of abdominal herniations. PMID:21860678

  4. 78 FR 34039 - Magnuson-Stevens Act Provisions; General Provisions for Domestic Fisheries; Application for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ..., fecundity, bioelectrical impedance analysis (BIA), food habits, and genetic research. The yellowtail... dependent catch data and biological samples. Regulations under the Magnuson-Stevens Fishery Conservation and... Exempted Fishing Permit (EFP) on April 11, 2013, to enable data collection activities that the regulations...

  5. What makes a BIA equation unique? Validity of 8-electrode multifrequency-BIA to estimate body compostion in a healthy adult population

    USDA-ARS?s Scientific Manuscript database

    The validity of bioelectrical impedance analysis (BIA) for body composition analysis is limited by assumptions relating to body shape. Improvement in BIA technology could overcome these limitations and reduce the population specificity of the BIA algorithm. BIA equations for the prediction of fat ...

  6. Tracking of electrochemical impedance of batteries

    NASA Astrophysics Data System (ADS)

    Piret, H.; Granjon, P.; Guillet, N.; Cattin, V.

    2016-04-01

    This paper presents an evolutionary battery impedance estimation method, which can be easily embedded in vehicles or nomad devices. The proposed method not only allows an accurate frequency impedance estimation, but also a tracking of its temporal evolution contrary to classical electrochemical impedance spectroscopy methods. Taking into account constraints of cost and complexity, we propose to use the existing electronics of current control to perform a frequency evolutionary estimation of the electrochemical impedance. The developed method uses a simple wideband input signal, and relies on a recursive local average of Fourier transforms. The averaging is controlled by a single parameter, managing a trade-off between tracking and estimation performance. This normalized parameter allows to correctly adapt the behavior of the proposed estimator to the variations of the impedance. The advantage of the proposed method is twofold: the method is easy to embed into a simple electronic circuit, and the battery impedance estimator is evolutionary. The ability of the method to monitor the impedance over time is demonstrated on a simulator, and on a real Lithium ion battery, on which a repeatability study is carried out. The experiments reveal good tracking results, and estimation performance as accurate as the usual laboratory approaches.

  7. Abdominal binders may reduce pain and improve physical function after major abdominal surgery - a systematic review.

    PubMed

    Rothman, Josephine Philip; Gunnarsson, Ulf; Bisgaard, Thue

    2014-11-01

    Evidence for the effect of post-operative abdominal binders on post-operative pain, seroma formation, physical function, pulmonary function and increased intra-abdominal pressure among patients after surgery remains largely un-investigated. A systematic review was conducted. The PubMed, EMBASE and Cochrane databases were searched for studies on the use of abdominal binders after abdominal surgery or abdominoplasty. All types of clinical studies were included. Two independent assessors evaluated the scientific quality of the studies. The primary outcomes were pain, seroma formation and physical function. A total of 50 publications were identified; 42 publications were excluded leaving eight publications counting a total of 578 patients for analysis. Generally, the scientific quality of the studies was poor. Use of abdominal binder revealed a non-significant tendency to reduce seroma formation after laparoscopic ventral herniotomy and a non-significant reduction in pain. Physical function was improved, whereas evidence supports a beneficial effect on psychological distress after open abdominal surgery. Evidence also supports that intra-abdominal pressure increases with the use of abdominal binders. Reduction of pulmonary function during use of abdominal binders has not been revealed. Abdominal binders reduce post-operative psychological distress, but their effect on post-operative pain after laparotomy and seroma formation after ventral hernia repair remains unclear. Due to the sparse evidence and poor quality of the literature, solid conclusions may be difficult to make, and procedure-specific, high-quality randomised clinical trials are warranted.

  8. Abdominal Sepsis.

    PubMed

    De Waele, Jan J

    2016-08-01

    Abdominal infections are an important challenge for the intensive care physician. In an era of increasing antimicrobial resistance, selecting the appropriate regimen is important and, with new drugs coming to the market, correct use is important more than ever before and abdominal infections are an excellent target for antimicrobial stewardship programs. Biomarkers may be helpful, but their exact role in managing abdominal infections remains incompletely understood. Source control also remains an ongoing conundrum, and evidence is increasing that its importance supersedes the impact of antibiotic therapy. New strategies such as open abdomen management may offer added benefit in severely ill patients, but more data are needed to identify its exact role. The role of fungi and the need for antifungal coverage, on the other hand, have been investigated extensively in recent years, but at this point, it remains unclear who requires empirical as well as directed therapy.

  9. Abdominal Aortic Dissections

    PubMed Central

    Borioni, Raoul; Garofalo, Mariano; De Paulis, Ruggero; Nardi, Paolo; Scaffa, Raffaele; Chiariello, Luigi

    2005-01-01

    Isolated abdominal aortic dissections are rare events. Their anatomic and clinical features are different from those of atherosclerotic aneurysms. We report 4 cases of isolated abdominal aortic dissection that were successfully treated with surgical or endovascular intervention. The anatomic and clinical features and a review of the literature are also presented. PMID:15902826

  10. Da Vinci-assisted abdominal cerclage.

    PubMed

    Barmat, Larry; Glaser, Gretchen; Davis, George; Craparo, Frank

    2007-11-01

    To report the first placement of an abdominal cervicoisthmic cerclage using the da Vinci robot. Case report. Tertiary-care hospital. A 39-year-old female with a history of cervical insufficiency who required a cerclage and was not a candidate for transvaginal cerclage placement. Abdominal cervicoisthmic cerclage placement using the da Vinci robot. Ability to safely and successfully place an abdominal cerclage using the da Vinci robot. Abdominal cerclage was successfully placed using the da Vinci robot. The patient had minimal blood loss and was discharged to home on the same day as surgery. Da Vinci robot-assisted abdominal cerclage placement is an innovative application of robotic surgery and may alter the standard of care for women who require this surgery.

  11. Automated anatomical labeling method for abdominal arteries extracted from 3D abdominal CT images

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Hoang, Bui Huy; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Mori, Kensaku

    2012-02-01

    This paper presents an automated anatomical labeling method of abdominal arteries. In abdominal surgery, understanding of blood vessel structure concerning with a target organ is very important. Branching pattern of blood vessels differs among individuals. It is required to develop a system that can assist understanding of a blood vessel structure and anatomical names of blood vessels of a patient. Previous anatomical labbeling methods for abdominal arteries deal with either of the upper or lower abdominal arteries. In this paper, we present an automated anatomical labeling method of both of the upper and lower abdominal arteries extracted from CT images. We obtain a tree structure of artery regions and calculate feature values for each branch. These feature values include the diameter, curvature, direction, and running vectors of a branch. Target arteries of this method are grouped based on branching conditions. The following processes are separately applied for each group. We compute candidate artery names by using classifiers that are trained to output artery names. A correction process of the candidate anatomical names based on the rule of majority is applied to determine final names. We applied the proposed method to 23 cases of 3D abdominal CT images. Experimental results showed that the proposed method is able to perform nomenclature of entire major abdominal arteries. The recall and the precision rates of labeling are 79.01% and 80.41%, respectively.

  12. Functional abdominal pain.

    PubMed

    Grover, Madhusudan; Drossman, Douglas A

    2010-10-01

    Functional abdominal pain syndrome (FAPS) is a relatively less common functional gastrointestinal (GI) disorder defined by the presence of constant or frequently recurring abdominal pain that is not associated with eating, change in bowel habits, or menstrual periods (Drossman Gastroenterology 130:1377-1390, 2006), which points to a more centrally targeted (spinal and supraspinal) basis for the symptoms. However, FAPS is frequently confused with irritable bowel syndrome and other functional GI disorders in which abdominal pain is associated with eating and bowel movements. FAPS also differs from chronic abdominal pain associated with entities such as chronic pancreatitis or chronic inflammatory bowel disease, in which the pain is associated with peripherally acting factors (eg, gut inflammation or injury). Given the central contribution to the pain experience, concomitant psychosocial disturbances are common and strongly influence the clinical expression of FAPS, which also by definition is associated with loss of daily functioning. These factors make it critical to use a biopsychosocial construct to understand and manage FAPS, because gut-directed treatments are usually not successful in managing this condition.

  13. Reactanceless synthesized impedance bandpass amplifier

    NASA Technical Reports Server (NTRS)

    Kleinberg, L. L. (Inventor)

    1985-01-01

    An active R bandpass filter network is formed by four operational amplifier stages interconnected by discrete resistances. One pair of stages synthesize an equivalent input impedance of an inductance (L sub eq) in parallel with a discrete resistance (R sub o) while the second pair of stages synthesizes an equivalent input impedance of a capacitance (C sub eq) serially coupled to another discrete resistance (R sub i) coupled in parallel with the first two stages. The equivalent input impedances aggregately define a tuned resonant bandpass filter in the roll-off regions of the operational amplifiers.

  14. Assessment of distribution of ventilation by electrical impedance tomography in standing horses.

    PubMed

    Ambrisko, T D; Schramel, J P; Adler, A; Kutasi, O; Makra, Z; Moens, Y P S

    2016-02-01

    The aim was to evaluate the feasibility of using electrical impedance tomography (EIT) in horses. Thoracic EIT was used in nine horses. Thoracic and abdominal circumference changes were also measured with respiratory ultrasound plethysmography (RUP). Data were recorded during baseline, rebreathing of CO2 and sedation. Three breaths were selected for analysis from each recording. During baseline breathing, horses regularly took single large breaths (sighs), which were also analysed. Functional EIT images were created using standard deviations (SD) of pixel signals and correlation coefficients (R) of each pixel signal with a reference respiratory signal. Left-to-right ratio, centre-of-ventilation and global-inhomogeneity-index were calculated. RM-ANOVA and Bonferroni tests were used (P < 0.05). Distribution of ventilation shifted towards right during sighs and towards dependent regions during sighs, rebreathing and sedation. Global-inhomogeneity-index did not change for SD but increased for R images during sedation. The sum of SDs for the respiratory EIT signals correlated well with thoracic (r(2) = 0.78) and abdominal (r(2) = 0.82) tidal circumferential changes. Inverse respiratory signals were identified on the images at sternal location and based on reviewing CT images, seemed to correspond to location of gas filled intestines. Application of EIT in standing non-sedated horses is feasible. EIT images may provide physiologically useful information even in situations, such as sighs, that cannot easily be tested by other methods.

  15. [Abdominal traumatic evisceration: reconstruction abdominal wall with biologic mesh and negative pressure therapy].

    PubMed

    Jiménez Gómez, M; Betancor Rivera, N; Lima Sánchez, J; Hernández Hernández, J R

    2016-04-10

    Abdominal traumatic evisceration as a result of high energy trauma is uncommon. Once repaired the possible internal damage, an abdominal wall defect of high complexity may exist, whose reconstruction represents a surgical challenge. Politraumatized male with important abdominal muculocutaneous avulsion and evisceration. After initial repair, the patient developed a big eventration in which we use a porcine dermis-derived mesh (Permacol TM ), a safe and effective alternative in abdominal wall repair, thanks to its seamless integration with other tissues, even when exposed. Negative pressure therapy has been used for the management of wound complications after surgical implantation of PermacolTM mesh. We describe our experience with the use of PermacolTM mesh and negative pressure therapy to aid the wound closure after skin necrosis and exposed mesh.

  16. Intra-abdominal pressure during swimming.

    PubMed

    Moriyama, S; Ogita, F; Huang, Z; Kurobe, K; Nagira, A; Tanaka, T; Takahashi, H; Hirano, Y

    2014-02-01

    The present study aimed to determine the intra-abdominal pressure during front crawl swimming at different velocities in competitive swimmers and to clarify the relationships between stroke indices and changes in intra-abdominal pressure. The subjects were 7 highly trained competitive collegiate male swimmers. Intra-abdominal pressure was measured during front crawl swimming at 1.0, 1.2 and 1.4 m · s(-1) and during the Valsalva maneuver. Intra-abdominal pressure was taken as the difference between minimum and maximum values, and the mean of 6 stable front crawl stroke cycles was used. Stroke rate and stroke length were also measured as stroke indices. There were significant differences in stroke rate among all velocities (P < 0.05). However, there was no significant difference in stroke length by velocity. Significant within-subject correlations between intra-abdominal pressure and stroke rate or stroke length (P < 0.01) were observed, although there were no significant correlations between intra-abdominal pressure and stroke indices when controlling for swimming velocity. These findings do not appear to support the effectiveness of trunk training performed by competitive swimmers aimed at increasing intra-abdominal pressure. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... plaque buildup causes the walls of the abdominal aorta to become weak and bulge outward like a ... treated? What is an abdominal aortic aneurysm? The aorta, the largest artery in the body, is a ...

  18. Abdominal Wall Endometriosis Mimicking Metastases.

    PubMed

    Nambiar, Rakul; Anoop, T M; Mony, Rari P

    2018-06-01

    Abdominal wall lesions can be broadly divided into nontumorous and tumorous conditions. Nontumorous lesions include congenital lesion, abdominal wall hernia, inflammation and infection, vascular lesions, and miscellaneous conditions like hematoma. Tumorous lesions include benign and malignant neoplasms. Here, we report an unusual case of abdominal wall endometriosis mimicking metastases in a patient with breast carcinoma.

  19. Scattering by a groove in an impedance plane

    NASA Technical Reports Server (NTRS)

    Bindiganavale, Sunil; Volakis, John L.

    1993-01-01

    An analysis of two-dimensional scattering from a narrow groove in an impedance plane is presented. The groove is represented by a impedance surface and the problem reduces to that of scattering from an impedance strip in an otherwise uniform impedance plane. On the basis of this model, appropriate integral equations are constructed using a form of the impedance plane Green's functions involving rapidly convergent integrals. The integral equations are solved by introducing a single basis representation of the equivalent current on the narrow impedance insert. Both transverse electric (TE) and transverse magnetic (TM) polarizations are treated. The resulting solution is validated by comparison with results from the standard boundary integral method (BIM) and a high frequency solution. It is found that the presented solution for narrow impedance inserts can be used in conjunction with the high frequency solution for the characterization of impedance inserts of any given width.

  20. Effects of various organic carbon sources on simultaneous V(V) reduction and bioelectricity generation in single chamber microbial fuel cells.

    PubMed

    Hao, Liting; Zhang, Baogang; Cheng, Ming; Feng, Chuanping

    2016-02-01

    Four ordinary carbon sources affecting V(V) reduction and bioelectricity generation in single chamber microbial fuel cells (MFCs) were investigated. Acetate supported highest maximum power density of 589.1mW/m(2), with highest V(V) removal efficiency of 77.6% during 12h operation, compared with glucose, citrate and soluble starch. Exorbitant initial V(V) concentration led to lower V(V) removal efficiencies and power outputs. Extra addition of organics had little effect on the improvement of MFCs performance. V(V) reduction and bioelectricity generation were enhanced and then suppressed by the increase of conductivity. The larger the external resistance, the higher the V(V) removal efficiencies and voltage outputs. High-throughput 16S rRNA gene pyrosequencing analysis implied the accumulation of Enterobacter which had the capabilities of V(V) reduction, electrochemical activity and fermentation, accompanied with other functional species as Pseudomonas, Spirochaeta, Sedimentibacter and Dysgonomonas. This study steps forward to remediate V(V) contaminated environment based on MFC technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Nutrition screening and assessment of anthropometry and bioelectrical impedance in the frail elderly: a clinical appraisal of methodology in a clinical setting.

    PubMed

    Davidson, Jeanette; Getz, Majorie

    2004-01-01

    Nutrition screening is recommended to identify those at risk for malnutrition; nutrition assessment by anthropometry and impedance is widely used to indicate nutritional status but may be problematical in the frail elderly in nursing homes. Acceptability, availability, suitability and appropriate reference data influence clinical application of these measurements. In our study, nutrition screening and assessment methodology were evaluated in 46 nursing home residents, mean age 86.3 +/- 6.6 years, mean weight 66.1 +/- 12.9 kg, mean height 163.1 +/- 9.6 cm, and mean BMI 24.9 +/- 4.6 kg/m2. Significant correlations (P < 0.05) were found in all measures of body weight, BMI, body fatness and leanness. Interpretation of data by five different reference standards and cutoff points revealed wide variation in identification of malnutrition by anthropometry. Appropriate reference data for body lean and fatness are not yet available. Thus, population-specific methodology and reference standards are of crucial importance.

  2. Impedance analysis of acupuncture points and pathways

    NASA Astrophysics Data System (ADS)

    Teplan, Michal; Kukučka, Marek; Ondrejkovičová, Alena

    2011-12-01

    Investigation of impedance characteristics of acupuncture points from acoustic to radio frequency range is addressed. Discernment and localization of acupuncture points in initial single subject study was unsuccessfully attempted by impedance map technique. Vector impedance analyses determined possible resonant zones in MHz region.

  3. Abdominal emergencies in pediatrics.

    PubMed

    Coca Robinot, D; Liébana de Rojas, C; Aguirre Pascual, E

    2016-05-01

    Abdominal symptoms are among the most common reasons for pediatric emergency department visits, and abdominal pain is the most frequently reported symptom. Thorough history taking and physical examination can often reach the correct diagnosis. Knowing the abdominal conditions that are most common in each age group can help radiologists narrow the differential diagnosis. When imaging tests are indicated, ultrasonography is usually the first-line technique, enabling the diagnosis or adding relevant information with the well-known advantages of this technique. Nowadays, plain-film X-ray studies are reserved for cases in which perforation, bowel obstruction, or foreign body ingestion is suspected. It is also important to remember that abdominal pain can also occur secondary to basal pneumonia. CT is reserved for specific indications and in individual cases, for example, in patients with high clinical suspicion of abdominal disease and inconclusive findings at ultrasonography. We review some of the most common conditions in pediatric emergencies, the different imaging tests indicated in each case, and the imaging signs in each condition. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  4. Abdominal Complications after Severe Burns

    DTIC Science & Technology

    2009-05-01

    abdominal compartment syndrome, schemic bowel, biliary disease, peptic ulcer disease and astritis requiring laparotomy, small bowel obstruction, rimary fungal...abdominal complications was 25%, with Curl- ng’s ulcer the most common malady (54% of the total), ollowed by esophageal lesions (17%), hemorrhagic...complications in- luded trauma exploratory laparotomy, abdominal com- artment syndrome, ischemic bowel, biliary disease, peptic lcer disease and gastritis, large

  5. Factors confounding impedance catheter volume measurements in vitro.

    PubMed

    Bielefeld, M R; Cabreriza, S E; Spotnitz, H M

    1993-06-01

    The impedance catheter allows continuous measurement of ventricular volume. External influences have been described as causing parallel shifts in impedance-measured volumes; however, factors affecting impedance measurements in a nonparallel manner have not been fully characterized. Accordingly, an impedance catheter was placed inside a latex balloon into which known volumes of normal saline solution were injected. Conductive and nonconductive materials were individually placed within the balloon. Impedance was measured with materials touching (T) or not touching (NT) the catheter. Impedance-measured volumes were plotted versus actual volumes. Compared with the line of identity (LID), a statistical difference (p < 0.05) was found in the slopes in the presence of metallic objects only. These included a pacing lead (T, NT) (mT = 1.32m mNT = 1.29 versus mLID = 1.00), titanium (T) (mT = 1.68 versus mLID = 1.00), and aluminum (NT) (mNT = 0.72 versus mLID = 1.00). These changes in slope indicate nonparallel effects on impedance that confound the ability of the impedance catheter to determine volumes in vitro. These observations imply that serial calibration of both the slope constant (alpha) and the intercept (parallel conductance) of impedance may be necessary for in vivo measurements of ventricular volume based on impedance in the presence of metallic objects.

  6. Surface Electromyographic Activity of the Abdominal Muscles During Pelvic-Tilt and Abdominal-Hollowing Exercises.

    PubMed

    Drysdale, Cheri L.; Earl, Jennifer E.; Hertel, Jay

    2004-03-01

    OBJECTIVE: To investigate surface electromyographic (EMG) activity of the rectus abdominus and external oblique abdominus muscles during pelvic-tilt and abdominal-hollowing exercises performed in different positions. DESIGN AND SETTING: 2 x 3 (exercise by position) within-subjects design with repeated measures on both factors. All testing was performed in a university laboratory. SUBJECTS: Twenty-six healthy, active young adult females. MEASUREMENTS: Surface EMG activity was recorded from the left and right rectus abdominus and external oblique muscles while the 2 exercises (pelvic tilt and abdominal hollowing) were performed in different positions (standard, legs supported, and legs unsupported). The standard position was supine in the crook-lying position, the supported position was with hips and knees flexed to 90 degrees and legs supported on a platform, and the unsupported position was with hips and knees flexed to 90 degrees without external support. Peak EMG activity was normalized to a maximum voluntary isometric contraction for each muscle. RESULTS: For the rectus abdominus, there was an interaction between position and activity. Abdominal hollowing produced significantly less activity than the pelvic tilt in all positions. The difference between the 2 exercises with the legs unsupported was of a greater magnitude than the other 2 positions. For the external obliques, there was significantly lower activity during the abdominal hollowing compared with the pelvic tilting. The greatest muscle activity occurred with the legs-unsupported position during both exercises. CONCLUSIONS: Abdominal-hollowing exercises produced less rectus abdominus and external oblique activity than pelvic-tilting exercises. Abdominal hollowing may be performed with minimal activation of the large global abdominal muscles.

  7. Electrical Impedance Spectroscopy Study of Biological Tissues

    PubMed Central

    Dean, D.A.; Ramanathan, T.; Machado, D.; Sundararajan, R.

    2008-01-01

    The objective of this study was to investigate the electrical impedance properties of rat lung and other tissues ex vivo using Electrical Impedance Spectroscopy. Rat lungs (both electroporated and naïve (untreated)), and mesenteric vessels (naïve) were harvested from male Sprague-Dawley rats; their electrical impedance were measured using a Solartron 1290 impedance analyzer. Mouse lung and heart samples (naïve) were also studied. The resistance (Real Z, ohm) and the reactance (Im Z, negative ohm)) magnitudes and hence the Cole-Cole (Real Z versus Im Z) plots are different for the electroporated lung and the naive lung. The results confirm the close relationship between the structure and the functional characteristic. These also vary for the different biological tissues studied. The impedance values were higher at low frequencies compared to those at high frequencies. This study is of practical interest for biological applications of electrical pulses, such as electroporation, whose efficacy depends on cell type and its electrical impedance characteristics. PMID:19255614

  8. Blunt abdominal trauma in children.

    PubMed

    Schonfeld, Deborah; Lee, Lois K

    2012-06-01

    This review will examine the current evidence regarding pediatric blunt abdominal trauma and the physical exam findings, laboratory values, and radiographic imaging associated with the diagnosis of intra-abdominal injuries (IAI), as well as review the current literature on pediatric hollow viscus injuries and emergency department disposition after diagnosis. The importance of the seat belt sign on physical examination and screening laboratory data remains controversial, although screening hepatic enzymes are recommended in the evaluation of nonaccidental trauma to identify occult abdominal organ injuries. Focused Assessment with Sonography for Trauma (FAST) has modest sensitivity for hemoperitoneum and IAI in the pediatric trauma patient. Patients with concern for undiagnosed IAI, including bowel injury, may be considered for hospital admission and serial abdominal exams without an increased risk of complications, if an exploratory laparotomy is not performed emergently. Although the FAST exam is not recommended as the sole screening tool to rule out IAI in hemodynamically stable trauma patients, it may be used in conjunction with the physical exam and laboratory findings to identify children at risk for IAI. Children with a normal physical exam and normal abdominal CT may not require routine hospitalization after blunt abdominal trauma.

  9. Variable versus conventional lung protective mechanical ventilation during open abdominal surgery: study protocol for a randomized controlled trial.

    PubMed

    Spieth, Peter M; Güldner, Andreas; Uhlig, Christopher; Bluth, Thomas; Kiss, Thomas; Schultz, Marcus J; Pelosi, Paolo; Koch, Thea; Gama de Abreu, Marcelo

    2014-05-02

    General anesthesia usually requires mechanical ventilation, which is traditionally accomplished with constant tidal volumes in volume- or pressure-controlled modes. Experimental studies suggest that the use of variable tidal volumes (variable ventilation) recruits lung tissue, improves pulmonary function and reduces systemic inflammatory response. However, it is currently not known whether patients undergoing open abdominal surgery might benefit from intraoperative variable ventilation. The PROtective VARiable ventilation trial ('PROVAR') is a single center, randomized controlled trial enrolling 50 patients who are planning for open abdominal surgery expected to last longer than 3 hours. PROVAR compares conventional (non-variable) lung protective ventilation (CV) with variable lung protective ventilation (VV) regarding pulmonary function and inflammatory response. The primary endpoint of the study is the forced vital capacity on the first postoperative day. Secondary endpoints include further lung function tests, plasma cytokine levels, spatial distribution of ventilation assessed by means of electrical impedance tomography and postoperative pulmonary complications. We hypothesize that VV improves lung function and reduces systemic inflammatory response compared to CV in patients receiving mechanical ventilation during general anesthesia for open abdominal surgery longer than 3 hours. PROVAR is the first randomized controlled trial aiming at intra- and postoperative effects of VV on lung function. This study may help to define the role of VV during general anesthesia requiring mechanical ventilation. Clinicaltrials.gov NCT01683578 (registered on September 3 3012).

  10. Mechanical Impedance Modeling of Human Arm: A survey

    NASA Astrophysics Data System (ADS)

    Puzi, A. Ahmad; Sidek, S. N.; Sado, F.

    2017-03-01

    Human arm mechanical impedance plays a vital role in describing motion ability of the upper limb. One of the impedance parameters is stiffness which is defined as the ratio of an applied force to the measured deformation of the muscle. The arm mechanical impedance modeling is useful in order to develop a better controller for system that interacts with human as such an automated robot-assisted platform for automated rehabilitation training. The aim of the survey is to summarize the existing mechanical impedance models of human upper limb so to justify the need to have an improved version of the arm model in order to facilitate the development of better controller of such systems with ever increase in complexity. In particular, the paper will address the following issue: Human motor control and motor learning, constant and variable impedance models, methods for measuring mechanical impedance and mechanical impedance modeling techniques.

  11. Multi-gap high impedance plasma opening switch

    DOEpatents

    Mason, R.J.

    1996-10-22

    A high impedance plasma opening switch having an anode and a cathode and at least one additional electrode placed between the anode and cathode is disclosed. The presence of the additional electrodes leads to the creation of additional plasma gaps which are in series, increasing the net impedance of the switch. An equivalent effect can be obtained by using two or more conventional plasma switches with their plasma gaps wired in series. Higher impedance switches can provide high current and voltage to higher impedance loads such as plasma radiation sources. 12 figs.

  12. Multi-gap high impedance plasma opening switch

    DOEpatents

    Mason, Rodney J.

    1996-01-01

    A high impedance plasma opening switch having an anode and a cathode and at least one additional electrode placed between the anode and cathode. The presence of the additional electrodes leads to the creation of additional plasma gaps which are in series, increasing the net impedance of the switch. An equivalent effect can be obtained by using two or more conventional plasma switches with their plasma gaps wired in series. Higher impedance switches can provide high current and voltage to higher impedance loads such as plasma radiation sources.

  13. 21 CFR 874.1090 - Auditory impedance tester.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Auditory impedance tester. 874.1090 Section 874...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1090 Auditory impedance tester. (a) Identification. An auditory impedance tester is a device that is intended to change the air pressure in the...

  14. 21 CFR 874.1090 - Auditory impedance tester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Auditory impedance tester. 874.1090 Section 874...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1090 Auditory impedance tester. (a) Identification. An auditory impedance tester is a device that is intended to change the air pressure in the...

  15. Relationship between body fat and BMI in a U.S. Hispanic population-based cohort study: Results from HCHS/SOL

    USDA-ARS?s Scientific Manuscript database

    To evaluate the percentage of body fat (%BF)-BMI relationship, identify %BF levels corresponding to adult BMI cut points, and examine %BF-BMI agreement in a diverse Hispanic/Latino population. %BF by bioelectrical impedance analysis was corrected against %BF by 18O dilution in 434 participants of th...

  16. Surface Electromyographic Activity of the Abdominal Muscles During Pelvic-Tilt and Abdominal-Hollowing Exercises

    PubMed Central

    Drysdale, Cheri L.; Earl, Jennifer E.

    2004-01-01

    Objective: To investigate surface electromyographic (EMG) activity of the rectus abdominus and external oblique abdominus muscles during pelvic-tilt and abdominal-hollowing exercises performed in different positions. Design and Setting: 2 × 3 (exercise by position) within-subjects design with repeated measures on both factors. All testing was performed in a university laboratory. Subjects: Twenty-six healthy, active young adult females. Measurements: Surface EMG activity was recorded from the left and right rectus abdominus and external oblique muscles while the 2 exercises (pelvic tilt and abdominal hollowing) were performed in different positions (standard, legs supported, and legs unsupported). The standard position was supine in the crook-lying position, the supported position was with hips and knees flexed to 90° and legs supported on a platform, and the unsupported position was with hips and knees flexed to 90° without external support. Peak EMG activity was normalized to a maximum voluntary isometric contraction for each muscle. Results: For the rectus abdominus, there was an interaction between position and activity. Abdominal hollowing produced significantly less activity than the pelvic tilt in all positions. The difference between the 2 exercises with the legs unsupported was of a greater magnitude than the other 2 positions. For the external obliques, there was significantly lower activity during the abdominal hollowing compared with the pelvic tilting. The greatest muscle activity occurred with the legs-unsupported position during both exercises. Conclusions: Abdominal-hollowing exercises produced less rectus abdominus and external oblique activity than pelvic-tilting exercises. Abdominal hollowing may be performed with minimal activation of the large global abdominal muscles. PMID:15085209

  17. Intra-abdominal abscess demonstrating an unusually large intra-abdominal pattern on an indium-111 leukocyte scan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Black, R.R.; Fernandez-Ulloa, M.; ter Penning, B.

    1988-12-01

    Indium-111 WBC imaging of a patient with occult septicemia revealed a large focal pattern of radiopharmaceutical distribution within the abdominal cavity at 24 hours post radiopharmaceutical administration. This finding was felt to represent a large intra-abdominal abscess. A five liter peritoneal abscess was found at surgery. This case illustrates an unusual presentation of an intra-abdominal abscess.

  18. Temporary Abdominal Closure Combined With an Irrigating System Utilizing Hypochlorous Acid Solution to Decrease Abdominal Mucopurulence

    PubMed Central

    Matthews, Marc R.; Quan, Asia N.; Weir, Alexandra S.; Foster, Kevin N.; Caruso, Daniel M.

    2018-01-01

    Introduction: Leaving the abdominal cavity open is a well-described and frequently utilized technique in the treatment of severe intra-abdominal sepsis. Irrigation through a negative pressure wound therapy device is a technique employed to assist in the closure of wounds as well as the reduction of bacterial contamination. Furthermore, hypochlorous acid has been found to be safe and effective in microorganismal elimination from extremity wounds. There is no literature regarding the infusion of hypochlorous solution into the abdominal cavity for intra-abdominal sepsis or mucopurulent abscesses or biofilm. Objectives: A 47-year-old man with granulomatosis polyangiitis was started on weekly rituximab. After 4 infusions, skin sloughing, ultimately diagnosed as toxic epidermal necrolysis, developed. During the hospital course, he developed sepsis and bowel perforation necessitating an exploratory laparotomy. The abdomen was left open with a temporary abdominal closure using the Abthera open abdomen negative wound therapy device; however, the abdomen remained infected with visually diffuse, thickening mucopurulence despite multiple washouts. Therefore, a VAC Vera-Flo irrigation device was combined with the Abthera open abdomen negative wound therapy device and cyclical irrigation of hypochlorous acid. After 72 hours, the purulence visually was improved and no adverse events were recorded with the placement of intra-abdominal hypochlorous acid. Conclusions: The combination of two medical devices for the intra-abdominal instillation of irrigation is considered “off-label use” from the manufacturer's recommendations. In addition, the repeated instillation of hypochlorous acid solution has not been described but was noted to have visually decreased the contaminated effluent within the intra-abdominal fluid. PMID:29527250

  19. Impedance in School Screening Programs.

    ERIC Educational Resources Information Center

    Robarts, John T.

    1985-01-01

    This paper examines the controversy over use of impedance screening in public schools to identify students with hearing problems, including otitis media, a common ear condition in infants and young children. It cites research that questions the value of pure tone screening as a single test and raises critics' objections to the use of impedance,…

  20. Fossilized bioelectric wire – the trace fossil Trichichnus

    PubMed Central

    Kędzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

    2015-01-01

    The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the oxic–anoxic interface zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus, formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that it is produced by modern large, mat-forming, sulfide-oxidizing bacteria, belonging mostly to Thioploca-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized “electric wire”. PMID:26290671

  1. Energy expenditure in caving

    PubMed Central

    Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio

    2017-01-01

    The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225–287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000–1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue. PMID:28158208

  2. Energy expenditure in caving.

    PubMed

    Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio; Rinaldi, Andrea C

    2017-01-01

    The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225-287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000-1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue.

  3. Acoustic ground impedance meter

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.

    1981-01-01

    A compact, portable instrument was developed to measure the acoustic impedance of the ground, or other surfaces, by direct pressure-volume velocity measurement. A Helmholz resonator, constructed of heavy-walled stainless steel but open at the bottom, is positioned over the surface having the unknown impedance. The sound source, a cam-driven piston of known stroke and thus known volume velocity, is located in the neck of the resonator. The cam speed is a variable up to a maximum 3600 rpm. The sound pressure at the test surface is measured by means of a microphone flush-mounted in the wall of the chamber. An optical monitor of the piston displacement permits measurement of the phase angle between the volume velocity and the sound pressure, from which the real and imaginary parts of the impedance can be evaluated. Measurements using a 5-lobed cam can be made up to 300 Hz. Detailed design criteria and results on a soil sample are presented.

  4. Impedance Measurement Box

    ScienceCinema

    Christophersen, Jon; Morrison, Bill

    2018-02-14

    Energy storage devices, primarily batteries, are now more important to consumers, industries and the military. With increasing technical complexity and higher user expectations, there is also a demand for highly accurate state-of-health battery assessment techniques. IMB incorporates patented, proprietary, and tested capabilities using control software and hardware that can be part of an embedded monitoring system. IMB directly measures the wideband impedance spectrum in seconds during battery operation with no significant impact on service life. It also can be applied to batteries prior to installation, confirming health before entering active service, as well as during regular maintenance. For more information about this project, visit http://www.inl.gov/rd100/2011/impedance-measurement-box/

  5. [Diagnostic imaging and acute abdominal pain].

    PubMed

    Liljekvist, Mads Svane; Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

    2015-01-19

    Acute abdominal pain is a common clinical condition. Clinical signs and symptoms can be difficult to interpret, and diagnostic imaging may help to identify intra-abdominal disease. Conventional X-ray, ultrasound (US) and computed tomography (CT) of the abdomen vary in usability between common surgical causes of acute abdominal pain. Overall, conventional X-ray cannot confidently diagnose or rule out disease. US and CT are equally trustworthy for most diseases. US with subsequent CT may enhance diagnostic precision. Magnetic resonance seems promising for future use in acute abdominal imaging.

  6. Changes in transthoracic electrical impedance at high altitude.

    PubMed

    Hoon, R S; Balasubramanian, V; Tiwari, S C; Mathew, O P; Behl, A; Sharma, S C; Chadha, K S

    1977-01-01

    Mean transthoracic electrical impedance (impedance) which is inversely related to intrathoracic extravascular fluid volume was measured in 121 normal healthy volunteers at sea-level and at 3658 metres altitude. Fifty (group A) reached the high altitude location after an hour's journey in a pressurised aircraft. Twenty-five (group D) underwent slow road ascent including acclimatisation en route. Thirty permanent residents (group B) and 16 temporary residents at high altitude (group C) were also studied. Serial studies in the 30 subjects of group A who developed symptoms of high altidue sickness showed a significant decrease of impedance up to the fourth day of exposure to high altitude which later returned to normal. The 4 volunteers who developed severe symptoms showed the largest drop in impedance. A case of acute pulmonary oedema developing at 4300 metres showed an impedance value of 24-1 ohms on admission. After effective treatment the impedance increased by 11-9 to 36-0 ohms. Twenty asymptomatic subjects of group A and 25 of group D showed a small average increase in impedance values at high altitude. These obstructions suggest that measurement of transthoracic electrical impedance may be a valuable means of detecting incipient high altitude pulmonary oedema.

  7. Geometric beam coupling impedance of LHC secondary collimators

    NASA Astrophysics Data System (ADS)

    Frasciello, Oscar; Tomassini, Sandro; Zobov, Mikhail; Salvant, Benoit; Grudiev, Alexej; Mounet, Nicolas

    2016-02-01

    The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep beam instabilities under control and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are among the major impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were higher by about a factor of 2 with respect to the theoretical predictions based on the LHC impedance model up to 2012. In that model the resistive wall impedance has been considered as the dominating impedance contribution for collimators. By carefully simulating also their geometric impedance we have contributed to the update of the LHC impedance model, reaching also a better agreement between the measured and simulated betatron tune shifts. During the just ended LHC Long Shutdown I (LSI), TCS/TCT collimators were replaced by new devices embedding BPMs and TT2-111R ferrite blocks. We present here preliminary estimations of their broad-band impedance, showing that an increase of about 20% is expected in the kick factors with respect to previous collimators without BPMs.

  8. FDTD modeling of thin impedance sheets

    NASA Technical Reports Server (NTRS)

    Luebbers, Raymond; Kunz, Karl

    1991-01-01

    Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. It is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods. These sheets are characterized by a discontinuity in the tangential magnetic field on either side of the sheet but no discontinuity in tangential electric field. This continuity, or single valued behavior of the electric field, allows the sheet current to be expressed in terms of an impedance multiplying this electric field.

  9. Alteration of bioelectrically-controlled processes in the embryo: a teratogenic mechanism for anticonvulsants.

    PubMed

    Hernández-Díaz, Sonia; Levin, Michael

    2014-08-01

    Maternal use of anticonvulsants during the first trimester of pregnancy has been associated with an elevated risk of major congenital malformations in the offspring. Whether the increased risk is caused by the specific pharmacological mechanisms of certain anticonvulsants, the underlying epilepsy, or common genetic or environmental risk factors shared by epilepsy and malformations has been controversial. We hypothesize that anticonvulsant therapies during pregnancy that attain more successful inhibition of neurotransmission might lead to both better seizure control in the mother and stronger alteration of bioelectrically-controlled processes in the embryo that result in structural malformations. We propose that development of pharmaceuticals that do not alter cell resting transmembrane voltage levels could result in safer drugs. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Broadband electrical impedance matching for piezoelectric ultrasound transducers.

    PubMed

    Huang, Haiying; Paramo, Daniel

    2011-12-01

    This paper presents a systematic method for designing broadband electrical impedance matching networks for piezoelectric ultrasound transducers. The design process involves three steps: 1) determine the equivalent circuit of the unmatched piezoelectric transducer based on its measured admittance; 2) design a set of impedance matching networks using a computerized Smith chart; and 3) establish the simulation model of the matched transducer to evaluate the gain and bandwidth of the impedance matching networks. The effectiveness of the presented approach is demonstrated through the design, implementation, and characterization of impedance matching networks for a broadband acoustic emission sensor. The impedance matching network improved the power of the acquired signal by 9 times.

  11. Determining blood and plasma volumes using bioelectrical response spectroscopy

    NASA Technical Reports Server (NTRS)

    Siconolfi, S. F.; Nusynowitz, M. L.; Suire, S. S.; Moore, A. D. Jr; Leig, J.

    1996-01-01

    We hypothesized that an electric field (inductance) produced by charged blood components passing through the many branches of arteries and veins could assess total blood volume (TBV) or plasma volume (PV). Individual (N = 29) electrical circuits (inductors, two resistors, and a capacitor) were determined from bioelectrical response spectroscopy (BERS) using a Hewlett Packard 4284A Precision LCR Meter. Inductance, capacitance, and resistance from the circuits of 19 subjects modeled TBV (sum of PV and computed red cell volume) and PV (based on 125I-albumin). Each model (N = 10, cross validation group) had good validity based on 1) mean differences (-2.3 to 1.5%) between the methods that were not significant and less than the propagated errors (+/- 5.2% for TBV and PV), 2) high correlations (r > 0.92) with low SEE (< 7.7%) between dilution and BERS assessments, and 3) Bland-Altman pairwise comparisons that indicated "clinical equivalency" between the methods. Given the limitation of this study (10 validity subjects), we concluded that BERS models accurately assessed TBV and PV. Further evaluations of the models' validities are needed before they are used in clinical or research settings.

  12. Simultaneous wastewater treatment and bioelectricity production in microbial fuel cells using cross-linked chitosan-graphene oxide mixed-matrix membranes.

    PubMed

    Holder, Shima L; Lee, Ching-Hwa; Popuri, Srinivasa R

    2017-05-01

    Microbial fuel cells (MFCs) are emerging technology for wastewater treatment by chemical oxygen demand (COD) reduction and simultaneous bioelectricity production. Fabrication of an effective proton exchange membrane (PEM) is a vital component for MFC performance. In this work, green chitosan-based (CS) PEMs were fabricated with graphene oxide (GO) as filler material (CS-GO) and cross-linked with phosphoric acid (CS-GO-P(24)) or sulfuric acid (CS-GO-S(24)) to determine their effect on PEM properties. Interrogation of the physicochemical, thermal, and mechanical properties of the cross-linked CS-GO PEMs demonstrated that ionic cross-linking based on the incorporation of PO 4 3- groups in the CS-GO mixed-matrix composites, when compared with sulfuric acid cross-linking commonly used in proton exchange membrane fuel cell (PEMFC) studies, generated additional density of ionic cluster domains, rendered enhanced sorption properties, and augmented the thermal and mechanical stability of the composite structure. Consequently, bioelectricity performance analysis in MFC application showed that CS-GO-P(24) membrane produced 135% higher power density than the CS-GO-S(24) MFC system. Simultaneously, 89.52% COD removal of primary clarifier municipal wastewater was achieved in the MFC operated with the CS-GO-P(24) membrane.

  13. Rotor damage detection by using piezoelectric impedance

    NASA Astrophysics Data System (ADS)

    Qin, Y.; Tao, Y.; Mao, Y. F.

    2016-04-01

    Rotor is a core component of rotary machinery. Once the rotor has the damage, it may lead to a major accident. Thus the quantitative rotor damage detection method based on piezoelectric impedance is studied in this paper. With the governing equation of piezoelectric transducer (PZT) in a cylindrical coordinate, the displacement along the radius direction is derived. The charge of PZT is calculated by the electric displacement. Then, by the use of the obtained displacement and charge, an analytic piezoelectric impedance model of the rotor is built. Given the circular boundary condition of a rotor, annular elements are used as the analyzed objects and spectral element method is used to set up the damage detection model. The Electro-Mechanical (E/M) coupled impedance expression of an undamaged rotor is deduced with the application of a low-cost impedance test circuit. A Taylor expansion method is used to obtain the approximate E/M coupled impedance expression for the damaged rotor. After obtaining the difference between the undamaged and damaged rotor impedance, a rotor damage detection method is proposed. This method can directly calculate the change of bending stiffness of the structural elements, it follows that the rotor damage can be effectively detected. Finally, a preset damage configuration is used for the numerical simulation. The result shows that the quantitative damage detection algorithm based on spectral element method and piezoelectric impedance proposed in this paper can identify the location and the severity of the damaged rotor accurately.

  14. Abdominal cocoon secondary to disseminated tuberculosis

    PubMed Central

    Puppala, Radha; Sripathi, Smiti; Kadavigere, Rajagopal; Koteshwar, Prakashini; Singh, Jyoti

    2014-01-01

    Abdominal cocoon, also known as sclerosing encapsulating peritonitis, represents a rare entity where a variable length of the small bowel is enveloped by a fibrocollagenous membrane giving the appearance of a cocoon. It may be asymptomatic and is often diagnosed incidentally at laparotomy. We present a rare case of abdominal cocoon due to abdominal tuberculosis. PMID:25239980

  15. Abdominal Pain in the Geriatric Patient.

    PubMed

    Magidson, Phillip D; Martinez, Joseph P

    2016-08-01

    With an aging population, emergency department clinicians can expect an increase in geriatric patients presenting with abdominal pain. Compared with younger patients, this patient population is less likely to present with classic symptoms, physical examination findings, and laboratory values of abdominal disease. However, the morbidity and mortality associated with elderly patients presenting with abdominal pathologic conditions are significant. For this reason, the clinician must be familiar with some subtle and not so subtle differences when caring for the geriatric patient with abdominal pain to ensure timely diagnosis and appropriate treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Nature's Electric Potential: A Systematic Review of the Role of Bioelectricity in Wound Healing and Regenerative Processes in Animals, Humans, and Plants.

    PubMed

    Tyler, Sheena E B

    2017-01-01

    Natural endogenous voltage gradients not only predict and correlate with growth and development but also drive wound healing and regeneration processes. This review summarizes the existing literature for the nature, sources, and transmission of information-bearing bioelectric signals involved in controlling wound healing and regeneration in animals, humans, and plants. It emerges that some bioelectric characteristics occur ubiquitously in a range of animal and plant species. However, the limits of similarities are probed to give a realistic assessment of future areas to be explored. Major gaps remain in our knowledge of the mechanistic basis for these processes, on which regenerative therapies ultimately depend. In relation to this, it is concluded that the mapping of voltage patterns and the processes generating them is a promising future research focus, to probe three aspects: the role of wound/regeneration currents in relation to morphology; the role of endogenous flux changes in driving wound healing and regeneration; and the mapping of patterns in organisms of extreme longevity, in contrast with the aberrant voltage patterns underlying impaired healing, to inform interventions aimed at restoring them.

  17. Nature's Electric Potential: A Systematic Review of the Role of Bioelectricity in Wound Healing and Regenerative Processes in Animals, Humans, and Plants

    PubMed Central

    Tyler, Sheena E. B.

    2017-01-01

    Natural endogenous voltage gradients not only predict and correlate with growth and development but also drive wound healing and regeneration processes. This review summarizes the existing literature for the nature, sources, and transmission of information-bearing bioelectric signals involved in controlling wound healing and regeneration in animals, humans, and plants. It emerges that some bioelectric characteristics occur ubiquitously in a range of animal and plant species. However, the limits of similarities are probed to give a realistic assessment of future areas to be explored. Major gaps remain in our knowledge of the mechanistic basis for these processes, on which regenerative therapies ultimately depend. In relation to this, it is concluded that the mapping of voltage patterns and the processes generating them is a promising future research focus, to probe three aspects: the role of wound/regeneration currents in relation to morphology; the role of endogenous flux changes in driving wound healing and regeneration; and the mapping of patterns in organisms of extreme longevity, in contrast with the aberrant voltage patterns underlying impaired healing, to inform interventions aimed at restoring them. PMID:28928669

  18. Anticonvulsants Teratogenic Mechanism Involves Alteration of Bioelectrically-controlled Processes in the Embryo. A hypothesis

    PubMed Central

    Hernández-Díaz, Sonia; Levin, Michael

    2014-01-01

    Maternal use of anticonvulsants during the first trimester of pregnancy has been associated with an elevated risk of major congenital malformations in the offspring. Whether the increased risk is caused by the specific pharmacological mechanisms of certain anticonvulsants, the underlying epilepsy, or common genetic or environmental risk factors shared by epilepsy and malformations is controversial. We hypothesize that anticonvulsant therapies during pregnancy that attain more successful inhibition of neurotransmission might lead to both better seizure control in the mother and stronger alteration of bioelectrically-controlled processes in the embryo that result in structural malformations. If our theory were correct, development of pharmaceuticals that do not alter cell resting transmembrane voltage levels could result in safer drugs. PMID:24815983

  19. Amplifiers for bioelectric events: a design with a minimal number of parts.

    PubMed

    MettingVanRijn, A C; Peper, A; Grimbergen, C A

    1994-05-01

    A design for an amplifier for bioelectric events is presented that has fewer parts than conventional designs. The design allows the construction of amplifiers of a high quality in terms of noise and common mode rejection, with reduced dimensions and with a lower power consumption. Gain, bandwidth and number of channels are easily adapted to a wide range of biomedical applications. An application example is given in the form of a multichannel EEG amplifier (gain is 20,000), in which each channel consists of three operational amplifiers (one single and one dual), six resistors and two capacitors. The equivalent input noise voltage and current are 0.15 microVrms and 1 pArms, respectively, in a bandwidth of 0.2-40 Hz, and a common mode rejection ratio of 136 dB is achieved without trimming.

  20. [Evaluation of nutritional Status in lung cancer using bio electrical impedance analysis and mini nutritional assessment].

    PubMed

    Daghfous, Hafaoua; El Ayeb, Wejdène; Alouane, Leila; Tritar, Fatma

    2014-12-01

    Malnutrition and cachexia were a frequent problem in lung cancer and increases the risks of morbidity and mortality in these patients. Bioelectrical impedance analysis (BIA) is easy, non-invasive and reproducible method that can be performed. Evaluate nutritional status in patients with primary lung cancer by Mini Nutritional Assessment (MNA), BIA and anthropometric values (weight, arm and calf circumferences) and correlate the nutritional parameters to severity of cancer and histopathology. The nutritional status of 73 cases of primary lung cancer was evaluated by anthropometric parameters, MNA test and impedencemetrie Results: According to body mass index (BMI), malnutrition, overweight and obesity were noted in 34,2%, 13,7% and 5,5%. According to BMI, free-fat mass index (FFMI) and fat mass index (FMI), the investigations occurred malnutrition and depletion of muscle in respectively 19,2% and 23,3% of cases. Fat depletion was noted in 21,9%. Overweight and obesity were detected in 6,8% and 5,5% of cases. Assessment by MNA, revealed that 28,7% of patients were already malnourished and 49,3% of patients were at risk of malnutrition. A significant correlation existed between the score of MNA and arm and calf circumferences, FFMI and FMI. FMI was significantly lower in group of patients with small lung carcinoma. Only FFMI allows early detection of malnutrition in cancer patients overestimated by measuring BMI and arm circumference was the better indicator of depletion of muscle.

  1. 21 CFR 870.2750 - Impedance phlebograph.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Impedance phlebograph. 870.2750 Section 870.2750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2750 Impedance phlebograph...

  2. 21 CFR 870.2770 - Impedance plethysmograph.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Impedance plethysmograph. 870.2770 Section 870.2770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2770 Impedance...

  3. Recovery after abdominal wall reconstruction.

    PubMed

    Jensen, Kristian Kiim

    2017-03-01

    Incisional hernia is a common long-term complication to abdominal surgery, occurring in more than 20% of all patients. Some of these hernias become giant and affect patients in several ways. This patient group often experiences pain, decreased perceived body image, and loss of physical function, which results in a need for surgical repair of the giant hernia, known as abdominal wall reconstruction. In the current thesis, patients with a giant hernia were examined to achieve a better understanding of their physical and psychological function before and after abdominal wall reconstruction. Study I was a systematic review of the existing standardized methods for assessing quality of life after incisional hernia repair. After a systematic search in the electronic databases Embase and PubMed, a total of 26 studies using standardized measures for assessment of quality of life after incisional hernia repair were found. The most commonly used questionnaire was the generic Short-Form 36, which assesses overall health-related quality of life, addressing both physical and mental health. The second-most common questionnaire was the Carolinas Comfort Scale, which is a disease specific questionnaire addressing pain, movement limitation and mesh sensation in relation to a current or previous hernia. In total, eight different questionnaires were used at varying time points in the 26 studies. In conclusion, standardization of timing and method of quality of life assessment after incisional hernia repair was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery pathway at the Digestive Disease Center, Bispebjerg Hospital, and compared to a control group of 16 patients included retrospectively in the period immediately prior to the

  4. An improved water-filled impedance tube.

    PubMed

    Wilson, Preston S; Roy, Ronald A; Carey, William M

    2003-06-01

    A water-filled impedance tube capable of improved measurement accuracy and precision is reported. The measurement instrument employs a variation of the standardized two-sensor transfer function technique. Performance improvements were achieved through minimization of elastic waveguide effects and through the use of sound-hard wall-mounted acoustic pressure sensors. Acoustic propagation inside the water-filled impedance tube was found to be well described by a plane wave model, which is a necessary condition for the technique. Measurements of the impedance of a pressure-release terminated transmission line, and the reflection coefficient from a water/air interface, were used to verify the system.

  5. Detection and quantification of intraperitoneal fluid using electrical impedance tomography.

    PubMed

    Sadleir, R J; Fox, R A

    2001-04-01

    A prototype electrical impedance tomography system was evaluated prior to its use for the detection of intraperitoneal bleeding, with the assistance of patients undergoing continuous ambulatory peritoneal dialysis (CAPD). The system was sensitive enough to detect small amounts of dialysis fluid appearing in subtractive images over short time periods. Uniform sensitivity to blood appearing anywhere within the abdominal cavity was produced using a post-reconstructive filter that corrected for changes in apparent resistivity of anomalies with their radial position. The image parameter used as an indication of fluid quantity, the resistivity index, varied approximately linearly with the quantity of fluid added. A test of the system's response to the introduction of conductive fluid out of the electrode plane (when a blood-equivalent fluid was added to the stomach) found that the sensitivity of the system was about half that observed in the electrode plane. Breathing artifacts were found to upset quantitative monitoring of intraperitoneal bleeding, but only on time scales short compared with the fluid administration rate. Longer term breathing changes, such as those due to variations in the functional residual capacity of the lungs, should ultimately limit the sensitivity over long time periods.

  6. Gold nanoparticles produced in situ mediate bioelectricity and hydrogen production in a microbial fuel cell by quantized capacitance charging.

    PubMed

    Kalathil, Shafeer; Lee, Jintae; Cho, Moo Hwan

    2013-02-01

    Oppan quantized style: By adding a gold precursor at its cathode, a microbial fuel cell (MFC) is demonstrated to form gold nanoparticles that can be used to simultaneously produce bioelectricity and hydrogen. By exploiting the quantized capacitance charging effect, the gold nanoparticles mediate the production of hydrogen without requiring an external power supply, while the MFC produces a stable power density. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Abdominal shotgun trauma: A case report

    PubMed Central

    Toutouzas, Konstantinos G; Larentzakis, Andreas; Drimousis, Panagiotis; Riga, Maria; Theodorou, Dimitrios; Katsaragakis, Stylianos

    2008-01-01

    Introduction One of the most lethal mechanisms of injury is shotgun wound and particularly the abdominal one. Case presentation We report a case of a 45 years old male suffering abdominal shotgun trauma, who survived his injuries. Conclusion The management of the abdominal shotgun wounds is mainly dependent on clinical examination and clinical judgment, while requires advanced surgical skills. PMID:18625076

  8. Abdominal cocoon secondary to disseminated tuberculosis.

    PubMed

    Puppala, Radha; Sripathi, Smiti; Kadavigere, Rajagopal; Koteshwar, Prakashini; Singh, Jyoti

    2014-09-19

    Abdominal cocoon, also known as sclerosing encapsulating peritonitis, represents a rare entity where a variable length of the small bowel is enveloped by a fibrocollagenous membrane giving the appearance of a cocoon. It may be asymptomatic and is often diagnosed incidentally at laparotomy. We present a rare case of abdominal cocoon due to abdominal tuberculosis. 2014 BMJ Publishing Group Ltd.

  9. Positional dependence of particles in microfludic impedance cytometry.

    PubMed

    Spencer, Daniel; Morgan, Hywel

    2011-04-07

    Single cell impedance cytometry is a label-free electrical analysis method that requires minimal sample preparation and has been used to count and discriminate cells on the basis of their impedance properties. This paper shows experimental and numerically simulated impedance signals for test particles (6 μm diameter polystyrene) flowing through a microfluidic channel. The variation of impedance signal with particle position is mapped using numerical simulation and these results match closely with experimental data. We demonstrate that for a nominal 40 μm × 40 μm channel, the impedance signal is independent of position over the majority of the channel area, but shows large experimentally verifiable variation at extreme positions. The parabolic flow profile in the channel ensures that most of the sample flows through the area of uniform signal. At high flow rates inertial focusing is observed; the particles flow in equal numbers through two equilibrium positions reducing the coefficient of variance (CV) in the impedance signals to negligible values.

  10. LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON

    PubMed Central

    Cole, Kenneth S.; Baker, Richard F.

    1941-01-01

    Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was approximately as predicted theoretically on the basis of the poorly conducting dielectric characteristics of the membrane previously determined. For the large majority of the axons, the impedance reached a maximum at a low frequency and the reactance then vanished at a frequency between 150 and 300 cycles per second. Below this frequency, the reactance was inductive, reaching a maximum and then approaching zero as the frequency was decreased. The inductive reactance is a property of the axon and requires that it contain an inductive structure. The variation of the impedance with interpolar distance indicates that the inductance is in the membrane. The impedance characteristics of the membrane as calculated from the measured longitudinal impedance of the axon may be expressed by an equivalent membrane circuit containing inductance, capacity, and resistance. For a square centimeter of membrane the capacity of 1 µf with dielectric loss is shunted by the series combination of a resistance of 400 ohms and an inductance of one-fifth henry. PMID:19873252

  11. High input impedance amplifier

    NASA Technical Reports Server (NTRS)

    Kleinberg, Leonard L.

    1995-01-01

    High input impedance amplifiers are provided which reduce the input impedance solely to a capacitive reactance, or, in a somewhat more complex design, provide an extremely high essentially infinite, capacitive reactance. In one embodiment, where the input impedance is reduced in essence, to solely a capacitive reactance, an operational amplifier in a follower configuration is driven at its non-inverting input and a resistor with a predetermined magnitude is connected between the inverting and non-inverting inputs. A second embodiment eliminates the capacitance from the input by adding a second stage to the first embodiment. The second stage is a second operational amplifier in a non-inverting gain-stage configuration where the output of the first follower stage drives the non-inverting input of the second stage and the output of the second stage is fed back to the non-inverting input of the first stage through a capacitor of a predetermined magnitude. These amplifiers, while generally useful, are very useful as sensor buffer amplifiers that may eliminate significant sources of error.

  12. FDTD modeling of thin impedance sheets

    NASA Technical Reports Server (NTRS)

    Luebbers, Raymond J.; Kunz, Karl S.

    1991-01-01

    Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods.

  13. Abdominal compartment syndrome related to noninvasive ventilation.

    PubMed

    De Keulenaer, Bart L; De Backer, Adelard; Schepens, Dirk R; Daelemans, Ronny; Wilmer, Alexander; Malbrain, Manu L N G

    2003-07-01

    To study the effects of noninvasive positive pressure ventilation (NIPPV) on intra-abdominal pressure. Single case report from a tertiary teaching hospital. A 65-year-old man who experienced a sudden respiratory and cardiovascular collapse during NIPPV. This was caused by gastric overdistension due to aerophagia followed by raised intra-abdominal pressure leading to intra-abdominal hypertension and abdominal compartment syndrome. The respiratory and cardiovascular problems resolved immediately after the introduction of a nasogastric tube. This resulted in normalization of IAP. This is the first case reported of an abdominal compartment syndrome related to NIPPV. Clinicians should be aware of this possible complication while using NIPPV.

  14. The utility of focused abdominal ultrasound in blunt abdominal trauma: a reappraisal.

    PubMed

    Helling, Thomas S; Wilson, Jennifer; Augustosky, Kim

    2007-12-01

    Focused assessment with sonography for trauma (FAST) has become commonplace in the management of blunt abdominal trauma. However, newer computed tomography (CT) scanners have decreased imaging time for trauma patients and provide more detailed examination of abdominal contents. It was the aim of the current study to evaluate practice patterns of FAST and abdominal CT in blunt trauma victims. This was a retrospective study of all blunt trauma patients (N = 299) who received at least 1 FAST examination in the emergency department by surgeons and were admitted. Patients were tracked for subsequent CT scanning, disposition from the emergency department, any operative findings, and survival. Twenty-one of 299 patients (7%) had a positive FAST. There were 7 deaths and 14 patients were taken directly to the operating room (OR) for control of abdominal bleeding. Thirty-one of 299 (10%) had equivocal FAST. There were 4 deaths and 8 patients were taken to the OR for control of abdominal bleeding. A total of 247 of the 299 patients had a negative FAST. CT scans were performed in 193: 15 showed a visceral injury. There were 13 deaths and 29 patients were taken to the OR (4 for bleeding). Patients with a positive FAST had a higher mortality than FAST-negative patients (P < .001) and greater likelihood for operation (P < .001). Those with equivocal FAST had a greater likelihood for operation than FAST-negative patients (P < .05). FAST examinations can identify patients at risk for hemorrhage and in whom operation may be needed and, therefore, can guide mobilization of hospital resources. FAST-negative patients can be managed expectantly, using more specific imaging techniques.

  15. Acoustic metamaterials with broadband and wide-angle impedance matching

    NASA Astrophysics Data System (ADS)

    Liu, Chenkai; Luo, Jie; Lai, Yun

    2018-04-01

    We propose a general approach to design broadband and wide-angle impedance-matched acoustic metamaterials. Such an unusual acoustic impedance matching characteristic can be well explained by using a spatially dispersive effective medium theory. For demonstrations, we used silicone rubber, which has a huge impedance contrast with water, to design one- and two-dimensional acoustic structures which are almost perfectly impedance matched to water for a wide range of incident angles and in a broad frequency band. Our work opens up an approach to realize extraordinary acoustic impedance matching properties via metamaterial-design techniques.

  16. Effect of abdominal negative-pressure wound therapy on the measurement of intra-abdominal pressure.

    PubMed

    García, Alberto Federico; Sánchez, Álvaro Ignacio; Gutiérrez, Álvaro José; Bayona, Juan Gabriel; Naranjo, María Paula; Lago, Sebastián; Puyana, Juan Carlos

    2018-07-01

    In critically ill surgical patients undergoing abdominal negative-pressure wound therapy (NPWT), it remains uncertain whether or not intra-abdominal pressure (IAP) measurements should be obtained when NPWT is activated. We aimed to determine agreement between IAP measured with and without NPWT. In this analytic cross-sectional study, critically ill surgical adults (≥18 y) requiring abdominal NPWT for temporary abdominal closure after a damage control laparotomy were selected. Patients with urinary tract injuries or with pelvic packing were excluded. Paired IAP measures were performed in the same patient, with and without NPWT; two different operators performed the measures unaware of the other's result. Bland-Altman methods assessed the agreement between the two measures. Subgroup analyses (trauma and nontrauma) were performed. There were 198 IAP measures (99 pairs) in 38 patients. Mean IAP with and without NPWT were 8.33 (standard deviation 4.01) and 8.65 (standard deviation 4.04), respectively. Mean IAP difference was -0.323 (95% confidence interval -0.748 to 0.101), and reference range for difference was -4.579 to 3.932 (P = 0.864). From 112 IAP measures (56 pairs) in 21 trauma patients, mean IAP difference was -0.268 (95% confidence interval -0.867 to 0.331), and reference range for the difference was -4.740 to 4.204 (P = 0.427). There was no statistically significant disagreement in IAP measures. IAP could be measured with or without NPWT. In critically ill surgical patients with abdominal NPWT for temporary abdominal closure, monitoring and management of IAP either with or without NPWT is recommended. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Solid phase microbial fuel cell (SMFC) for harnessing bioelectricity from composite food waste fermentation: influence of electrode assembly and buffering capacity.

    PubMed

    Mohan, S Venkata; Chandrasekhar, K

    2011-07-01

    Solid phase microbial fuel cells (SMFC; graphite electrodes; open-air cathode) were designed to evaluate the potential of bioelectricity production by stabilizing composite canteen based food waste. The performance was evaluated with three variable electrode-membrane assemblies. Experimental data depicted feasibility of bioelectricity generation from solid state fermentation of food waste. Distance between the electrodes and presence of proton exchange membrane (PEM) showed significant influence on the power yields. SMFC-B (anode placed 5 cm from cathode-PEM) depicted good power output (463 mV; 170.81 mW/m(2)) followed by SMFC-C (anode placed 5 cm from cathode; without PEM; 398 mV; 53.41 mW/m(2)). SMFC-A (PEM sandwiched between electrodes) recorded lowest performance (258 mV; 41.8 mW/m(2)). Sodium carbonate amendment documented marked improvement in power yields due to improvement in the system buffering capacity. SMFCs operation also documented good substrate degradation (COD, 76%) along with bio-ethanol production. The operation of SMFC mimicked solid-sate fermentation which might lead to sustainable solid waste management practices. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Quantification of blood volume by electrical impedance tomography using a tissue-equivalent phantom.

    PubMed

    Sadleir, R; Fox, R

    1998-11-01

    An in vivo electrical impedance tomography (EIT) system was designed to accurately estimate quantities of intra-peritoneal blood in the abdominal cavity. For this it is essential that the response is relatively independent of the position of the high conductivity anomaly (blood) in the body. The sensitivity of the system to the introduction of blood-equivalent resistivity anomalies was assessed by using a cylindrical tissue-equivalent phantom. It was found that a satisfactorily uniform response of the system in both radial (transverse) and axial (longitudinal) directions in the phantom could be achieved by filtering resistivity profile images obtained by EIT measurement, and by using extended electrodes to collect data. Post-processing of single impedance images gave rise to a quantity denoted the resistivity index. A filter was then used to remove the remaining radial variation of the resistivity index. It was calculated by evaluating the resistivity index of a number of theoretically calculated images, and constructing a correction filter similar to those used to remove lens imperfections, such as coma, in optical components. The 30% increase in the resistivity index observed when an anomaly was moved to the maximum extent allowed by the filter calculation (0.75 of the phantom radius) was reduced by the filter to 6%. A study of the axial dependence observed in the resistivity index using electrodes extended in the axial direction by +/-5 cm found that the variation in resistivity index with axial position was about half of that observed using small circular electrodes similar to those used in the Sheffield mark I system.

  19. Programmable Gain Amplifiers with DC Suppression and Low Output Offset for Bioelectric Sensors

    PubMed Central

    Carrera, Albano; de la Rosa, Ramón; Alonso, Alonso

    2013-01-01

    DC-offset and DC-suppression are key parameters in bioelectric amplifiers. However, specific DC analyses are not often explained. Several factors influence the DC-budget: the programmable gain, the programmable cut-off frequencies for high pass filtering and, the low cut-off values and the capacitor blocking issues involved. A new intermediate stage is proposed to address the DC problem entirely. Two implementations were tested. The stage is composed of a programmable gain amplifier (PGA) with DC-rejection and low output offset. Cut-off frequencies are selectable and values from 0.016 to 31.83 Hz were tested, and the capacitor deblocking is embedded in the design. Hence, this PGA delivers most of the required gain with constant low output offset, notwithstanding the gain or cut-off frequency selected. PMID:24084109

  20. Sensitivity analyses of acoustic impedance inversion with full-waveform inversion

    NASA Astrophysics Data System (ADS)

    Yao, Gang; da Silva, Nuno V.; Wu, Di

    2018-04-01

    Acoustic impedance estimation has a significant importance to seismic exploration. In this paper, we use full-waveform inversion to recover the impedance from seismic data, and analyze the sensitivity of the acoustic impedance with respect to the source-receiver offset of seismic data and to the initial velocity model. We parameterize the acoustic wave equation with velocity and impedance, and demonstrate three key aspects of acoustic impedance inversion. First, short-offset data are most suitable for acoustic impedance inversion. Second, acoustic impedance inversion is more compatible with the data generated by density contrasts than velocity contrasts. Finally, acoustic impedance inversion requires the starting velocity model to be very accurate for achieving a high-quality inversion. Based upon these observations, we propose a workflow for acoustic impedance inversion as: (1) building a background velocity model with travel-time tomography or reflection waveform inversion; (2) recovering the intermediate wavelength components of the velocity model with full-waveform inversion constrained by Gardner’s relation; (3) inverting the high-resolution acoustic impedance model with short-offset data through full-waveform inversion. We verify this workflow by the synthetic tests based on the Marmousi model.

  1. Intra-abdominal pressure: an integrative review

    PubMed Central

    Milanesi, Rafaela; Caregnato, Rita Catalina Aquino

    2016-01-01

    ABSTRACT There is a growing request for measuring intra-abdominal pressure in critically ill patients with acute abdominal pain to be clarified. Summarizing the research results on measurement of vesical intra-abdominal pressure and analyzing the level of evidence were the purposes of this integrative literature review, carried out based on the databases LILACS, MEDLINE and PubMed, from 2005 to July 2012. Twenty articles were identified, in that, 12 literature reviews, 4 descriptive and exploratory studies, 2 expert opinions, one prospective cohort study and one was an experience report. The vesical intra-abdominal pressure measurement was considered gold standard. There are variations in the technique however, but some common points were identified: complete supine position, in absence of abdominal contracture, in the end of expiration and expressed in mmHg. Most research results indicate keeping the transducer zeroed at the level of the mid-axillary line at the iliac crest level, and instill 25mL of sterile saline. Strong evidence must be developed. PMID:26958978

  2. Intestinal injury mechanisms after blunt abdominal impact.

    PubMed

    Cripps, N P; Cooper, G J

    1997-03-01

    Intestinal injury is frequent after non-penetrating abdominal trauma, particularly after modern, high-energy transfer impacts. Under these circumstances, delay in the diagnosis of perforation is a major contributor to morbidity and mortality. This study establishes patterns of intestinal injury after blunt trauma by non-penetrating projectiles and examines relationships between injury distribution and abdominal wall motion. Projectile impacts of variable momentum were produced in 31 anaesthetised pigs to cause abdominal wall motion of varying magnitude and velocity. No small bowel injury was observed at initial impact velocity of less than 40 m/s despite gross abdominal compression. At higher velocity, injury to the small bowel was frequent, irrespective of the degree of abdominal compression (P = 0.00044). Large bowel injury was observed at all impact velocities and at all degrees of abdominal compression. This study confirms the potential for intestinal injury in high velocity, low momentum impacts which do not greatly compress the abdominal cavity and demonstrates apparent differences in injury mechanisms for the small bowel and colon. Familiarity with injury mechanisms may reduce delays in the diagnosis of intestinal perforation in both military and civilian situations.

  3. A Newborn With Abdominal Pain.

    PubMed

    Alwan, Riham; Drake, Meredith; Gurria Juarez, Juan; Emery, Kathleen H; Shaaban, Aimen F; Szabo, Sara; Sobolewski, Brad

    2017-11-01

    A previously healthy 3-week-old boy presented with 5 hours of marked fussiness, abdominal distention, and poor feeding. He was afebrile and well perfused. His examination was remarkable for localized abdominal tenderness and distention. He was referred to the emergency department in which an abdominal radiograph revealed gaseous distention of the bowel with a paucity of gas in the pelvis. Complete blood cell count and urinalysis were unremarkable. His ongoing fussiness and abnormal physical examination prompted consultation with surgery and radiology. Our combined efforts ultimately established an unexpected diagnosis. Copyright © 2017 by the American Academy of Pediatrics.

  4. Validity of body composition assessment methods for older men with cardiac disease.

    PubMed

    Young, H; Porcari, J; Terry, L; Brice, G

    1998-01-01

    This study was designed to determine which of several body composition assessment methods was most accurate for patients with cardiac disease for the purpose of outcome measurement. Six body composition assessment methods were administered to each of 24 men with cardiac disease. Methods included circumference measurement, skinfold measurement, near-infrared interactance via the Futrex-5000, bioelectrical impedance via the BioAnalogics ElectroLipoGraph and Tanita TBF-150, and hydrostatic weighing, the criterion measure. A repeated measures analysis of variance indicated no significant (P > .05) difference between circumference and skinfold measurements compared to hydrostatic weighing. Near-infrared interactance presented the best standard error of estimates (3.5%) and the best correlation (r = .84) with hydrostatic weighing; however, the constant error was 3.76%. Bioelectrical impedance measured by the ElectroLipoGraph and TBF-150 instruments significantly underestimated percent body fat by 8.81% and 4.8%, respectively. In this study of middle-aged to older men with cardiac disease, the best method for determining body fat was circumferences. This technique was accurate, easy to administer, inexpensive, and had a lower error potential than the other techniques. Skinfold measurements were also closely related to hydrostatic weighing, but should be performed only by experienced practitioners because there is a greater potential for tester error in certain patients. In the future, near-infrared interactance measurements may be a viable technique for body composition assessment in patients with cardiac disease. However, algorithms specific to the population of patients with cardiac disease being tested must be developed before this technique can be routinely recommended for body composition assessment. Bioelectrical impedance assessment by either method is not recommended for patients with cardiac disease, as it consistently underestimated percent body fat when

  5. Acute abdomen in children due to extra-abdominal causes.

    PubMed

    Tsalkidis, Aggelos; Gardikis, Stefanos; Cassimos, Dimitrios; Kambouri, Katerina; Tsalkidou, Evanthia; Deftereos, Savas; Chatzimichael, Athanasios

    2008-06-01

    Acute abdominal pain in children is a common cause for referral to the emergency room and for subsequent hospitalization to pediatric medical or surgical departments. There are rare occasions when the abdominal pain is derived from extra-abdominal organs or systems. The aim of the present study was to establish the most common extra-abdominal causes of acute abdominal pain. The notes of all children (1 month-14 years of age) examined for acute abdominal pain in the Accident and Emergency (A&E) Department of Alexandroupolis District University Hospital in January 2001-December 2005 were analyzed retrospectively. Demographic data, clinical signs and symptoms, and laboratory findings were recorded, as well as the final diagnosis and outcome. Of a total number of 28 124 children who were brought to the A&E department, in 1731 the main complaint was acute abdominal pain. In 51 children their symptoms had an extra-abdominal cause, the most frequent being pneumonia (n = 15), tonsillitis (n = 10), otitis media (n = 9), and acute leukemia (n = 5). Both abdominal and extra-abdominal causes should be considered by a pediatrician who is confronted with a child with acute abdominal pain.

  6. [Clinical Approach to Abdominal Pain as Functional Origin].

    PubMed

    Ryu, Han Seung; Choi, Suck Chei

    2018-02-25

    Abdominal pain is a common symptom that patients refer to a hospital. Organic causes should be differentiated in patients with abdominal pain and treatment should be administered in accordance with the causes. A meticulous history taking and physical examination are highly useful in making a diagnosis, and blood tests, imaging modalities, and endoscopy are useful for confirming diagnosis. However, in many cases, patients have functional disorders with no obvious abnormal findings obtained even if many diagnostic tests are performed. Patients with functional disorders usually complain the vague abdominal pain located in the center and other portions of the abdominal area. Although the most representative disease is irritable bowel syndrome, functional abdominal pain syndrome is currently researched as a new disease entity of functional abdominal pain. As various receptors related to functional abdominal pain have been discovered, drugs associated with those receptors are used to treat the disorders, and additional new drugs are vigorously developed. In addition, medical therapy with pharmacological or non-pharmacological psychiatric treatment is effective for treating functional abdominal pain.

  7. Impedance measurements for detecting pathogens attached to antibodies

    DOEpatents

    Miles, Robin R.; Venkateswaran, Kodumudi S.; Fuller, Christopher K.

    2004-12-28

    The use of impedance measurements to detect the presence of pathogens attached to antibody-coated beads. In a fluidic device antibodies are immobilized on a surface of a patterned interdigitated electrode. Pathogens in a sample fluid streaming past the electrode attach to the immobilized antibodies, which produces a change in impedance between two adjacent electrodes, which impedance change is measured and used to detect the presence of a pathogen. To amplify the signal, beads coated with antibodies are introduced and the beads would stick to the pathogen causing a greater change in impedance between the two adjacent electrodes.

  8. Impedance of Barrier-Type Oxide Layer on Aluminum

    NASA Astrophysics Data System (ADS)

    Oh, Han-Jun; Kim, Jung-Gu; Jeong, Yong-Soo; Chi, Choong-Soo

    2000-12-01

    The impedance characteristics of barrier-type oxide layers on aluminum was studied using impedance spectroscopy. Since anodic films on Al have a variable stoichiometry with a gradual reduction of oxygen deficiency towards the oxide-electrolyte interface, the interpretation of impedance spectra for oxide layers is complex and the impedance of surface layers differs from those of ideal capacitors. This frequency response of the layer with conductance gradients cannot be described by a single resistance-capacitance (RC) element. The oxide layers of Al are properly described by the Young model of dielectric constant with a vertical decay of conductivity.

  9. Impedance-matched Marx generators

    NASA Astrophysics Data System (ADS)

    Stygar, W. A.; LeChien, K. R.; Mazarakis, M. G.; Savage, M. E.; Stoltzfus, B. S.; Austin, K. N.; Breden, E. W.; Cuneo, M. E.; Hutsel, B. T.; Lewis, S. A.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Reisman, D. B.; Sceiford, M. E.; Wisher, M. L.

    2017-04-01

    We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs). The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with L C time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22 -Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19 -Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.

  10. Gynecologic electrical impedance tomograph

    NASA Astrophysics Data System (ADS)

    Korjenevsky, A.; Cherepenin, V.; Trokhanova, O.; Tuykin, T.

    2010-04-01

    Electrical impedance tomography extends to the new and new areas of the medical diagnostics: lungs, breast, prostate, etc. The feedback from the doctors who use our breast EIT diagnostic system has induced us to develop the 3D electrical impedance imaging device for diagnostics of the cervix of the uterus - gynecologic impedance tomograph (GIT). The device uses the same measuring approach as the breast imaging system: 2D flat array of the electrodes arranged on the probe with handle is placed against the body. Each of the 32 electrodes of the array is connected in turn to the current source while the rest electrodes acquire the potentials on the surface. The current flows through the electrode of the array and returns through the remote electrode placed on the patient's limb. The voltages are measured relative to another remote electrode. The 3D backprojection along equipotential surfaces is used to reconstruct conductivity distribution up to approximately 1 cm in depth. Small number of electrodes enables us to implement real time imaging with a few frames per sec. rate. The device is under initial testing and evaluation of the imaging capabilities and suitability of usage.

  11. Prediction of lamb carcass composition by impedance spectroscopy.

    PubMed

    Altmann, M; Pliquett, U; Suess, R; von Borell, E

    2004-03-01

    The objective of this study was to compare impedance spectroscopy with resistance measurements at a single frequency (50 kHz) for the prediction of lamb carcass composition. The impedance spectrum is usually recorded by measuring the complex impedance at various frequencies (frequency domain); however, in this study, we also applied the faster and simpler measurement in the time domain (application of a current step and measurement of the voltage response). The study was carried out on 24 male, German Black-headed Mutton lambs with an average BW of 45 kg. Frequency- and time domain-based impedance measurements were collected at 20 min and 24 h postmortem with different electrode placements. Real and imaginary parts at various frequencies were calculated from the locus diagram. Left sides were dissected into lean, fat, and bone, and right sides were ground to determine actual carcass composition. Crude fat, crude protein, and moisture were chemically analyzed on ground samples. Frequency- and time domain-based measurements did not provide the same absolute impedance values; however, the high correlations (P < 0.001) between these methods for the "real parts" showed that they ranked individuals in the same order. Most of the time domain data correlated higher to carcass composition than did the frequency domain data. The real parts of impedance showed correlations between -0.37 (P > 0.05) and -0.74 (P < 0.001) to water, crude fat, lean, and fatty tissue, whereas the relations to CP were much lower (from 0.00 to -0.47, P < 0.05). Electrode placements at different locations did not substantially improve the correlations with carcass composition. The "imaginary parts" of impedance were not suitable for the prediction of carcass composition. The highest accuracy (R2 = 0.66) was reached for the estimation of crude fat percentage by a regression equation with the time domain-based impedance measured at 24 h postmortem. Furthermore, there was not a clear superiority of

  12. How I Manage Abdominal Injuries.

    ERIC Educational Resources Information Center

    Haycock, Christine E.

    1986-01-01

    In sports, abdominal injuries occur most frequently in cycling, horseback riding, and skiing. Most involve children, not adults. Any athlete sustaining a severe blow to the abdomen should be examined. Guidelines are provided for recognizing and treating injuries to the abdominal muscles, kidneys, spleen, and liver. (Author/MT)

  13. Superconducting active impedance converter

    DOEpatents

    Ginley, D.S.; Hietala, V.M.; Martens, J.S.

    1993-11-16

    A transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductors allows for appropriate signal amplification and impedance matching to processing electronics. The amplifier incorporates the superconducting flux flow transistor into a differential amplifier configuration which allows for operation over a wide temperature range, and is characterized by high gain, relatively low noise, and response times less than 200 picoseconds over at least a 10-80 K. temperature range. The invention is particularly useful when a signal derived from either far-IR focal plane detectors or from Josephson junctions is to be processed by higher signal/higher impedance electronics, such as conventional semiconductor technology. 12 figures.

  14. Superconducting active impedance converter

    DOEpatents

    Ginley, David S.; Hietala, Vincent M.; Martens, Jon S.

    1993-01-01

    A transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductor allows for appropriate signal amplification and impedance matching to processing electronics. The amplifier incorporates the superconducting flux flow transistor into a differential amplifier configuration which allows for operation over a wide temperature range, and is characterized by high gain, relatively low noise, and response times less than 200 picoseconds over at least a 10-80 K. temperature range. The invention is particularly useful when a signal derived from either far-IR focal plane detectors or from Josephson junctions is to be processed by higher signal/higher impedance electronics, such as conventional semiconductor technology.

  15. Temporary closure of the abdominal wall by use of silicone rubber sheets after operative repair of ruptured abdominal aortic aneurysms.

    PubMed

    Akers, D L; Fowl, R J; Kempczinski, R F; Davis, K; Hurst, J M; Uhl, S

    1991-07-01

    Management of patients after operative repair of abdominal aortic aneurysms can be further complicated if primary closure of the abdominal wall cannot be technically accomplished or is associated with profound increases in intraabdominal and peak inspiratory pressures. We recently treated five patients with ruptured abdominal aortic aneurysms and one patient with a ruptured thoracoabdominal aneurysm whose abdominal incisions had to be closed with a Dacron reinforced, silicone sheet. All patients were hemodynamically unstable either at admission to the hospital or became so during operation. Four patients required the insertion of a silicone rubber sheet at the primary operation because of massive retroperitoneal hematoma or edema of the bowel wall or both. Incisions in two patients were closed primarily, but the patients required reexploration and secondary closure with silicone rubber sheets because of the development of marked increases in peak inspiratory pressures, intraabdominal pressures, and decreased urinary output. Four of the six patients subsequently underwent successful removal of the silicone rubber sheets with delayed primary closure of the abdominal wall, and two others died before removal. The patient with the ruptured thoracoabdominal aneurysm died on postoperative day 20 because of pulmonary sepsis but had a healed abdominal incision. The three surviving patients have been discharged. A silicone rubber sheet may be necessary for closure of the abdominal wall after repair of ruptured abdominal aortic aneurysm in patients where primary abdominal wall closure is impossible or where it results in compromise in respiratory or renal function.

  16. Traumatic abdominal hernia complicated by necrotizing fasciitis.

    PubMed

    Martínez-Pérez, Aleix; Garrigós-Ortega, Gonzalo; Gómez-Abril, Segundo Ángel; Martí-Martínez, Eva; Torres-Sánchez, Teresa

    2014-11-01

    Necrotizing fasciitis is a critical illness involving skin and soft tissues, which may develop after blunt abdominal trauma causing abdominal wall hernia and representing a great challenge for physicians. A 52-year-old man was brought to the emergency department after a road accident, presenting blunt abdominal trauma with a large non-reducible mass in the lower-right abdomen. A first, CT showed abdominal hernia without signs of complication. Three hours after ICU admission, he developed hemodynamic instability. Therefore, a new CT scan was requested, showing signs of hernia complication. He was moved to the operating room where a complete transversal section of an ileal loop was identified. Five hours after surgery, he presented a new episode of hemodynamic instability with signs of skin and soft tissue infection. Due to the high clinical suspicion of necrotizing fasciitis development, wide debridement was performed. Following traumatic abdominal wall hernia (TAWH), patients can present unsuspected injuries in abdominal organs. Helical CT can be falsely negative in the early moments, leading to misdiagnosis. Necrotizing fasciitis is a potentially fatal infection and, consequently, resuscitation measures, wide-spectrum antibiotics, and early surgical debridement are required. This type of fasciitis can develop after blunt abdominal trauma following wall hernia without skin disruption.

  17. Laparoscopy In Unexplained Abdominal Pain: Surgeon's Perspective.

    PubMed

    Abdullah, Muhammad Tariq; Waqar, Shahzad Hussain; Zahid, Muhammad Abdul

    2016-01-01

    Unexplained abdominal pain is a common but difficult presenting feature faced by the clinicians. Such patients can undergo a number of investigations with failure to reach any diagnosis. The objective of this study was to evaluate the use of laparoscopy in the diagnosis and management of patients with unexplained abdominal pain. This cross-sectional study was conducted at Pakistan Institute of Medical Sciences Islamabad from January 2009 to December 2013. This study included 91 patients of unexplained abdominal pain not diagnosed by routine clinical examination and investigations. These patients were subjected to diagnostic laparoscopy for evaluation of their conditions and to confirm the diagnosis. These patients presented 43% of patients undergoing investigations for abdominal pain. Patients diagnosed with gynaecological problems were excluded to see surgeon's perspective. The findings and the outcomes of the laparoscopy were recorded and data was analyzed. Unexplained abdominal pain is common in females than in males. The most common laparoscopic findings were abdominal tuberculosis followed by appendicitis. Ninety percent patients achieved pain relief after laparoscopic intervention. Laparoscopy is both beneficial and safe in majority of patients with unexplained abdominal pain. General surgeons should acquire training and experience in laparoscopic surgery to provide maximum benefit to these difficult patients.

  18. Economics of abdominal wall reconstruction.

    PubMed

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Perforated peptic ulcer associated with abdominal compartment syndrome.

    PubMed

    Lynn, Jiun-Jen; Weng, Yi-Ming; Weng, Chia-Sui

    2008-11-01

    Abdominal compartment syndrome (ACS) is defined as an increased intra-abdominal pressure with adverse physiologic consequences. Abdominal compartment syndrome caused by perforated peptic ulcer is rare owing to early diagnosis and management. Delayed recognition of perforated peptic ulcer with pneumoperitoneum, bowel distension, and decreased abdominal wall compliance can make up a vicious circle and lead to ACS. We report a case of perforated peptic ulcer associated with ACS. A 74-year-old man with old stroke and dementia history was found to have distended abdomen, edema of bilateral legs, and cyanosis. Laboratory tests revealed deterioration of liver and kidney function. Abdominal compartment syndrome was suspected, and image study was arranged to find the cause. The study showed pneumoperitoneum, contrast stasis in heart with decreased caliber of vessels below the abdominal aortic level, and diffuse lymphedema at the abdominal walls. Emergent laparotomy was performed. Perforated peptic ulcer was noted and the gastrorrhaphy was done. The symptoms, and liver and kidney function improved right after emergent operation.

  20. Implementation and Validation of an Impedance Eduction Technique

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Jones, Michael G.; Gerhold, Carl H.

    2011-01-01

    Implementation of a pressure gradient method of impedance eduction in two NASA Langley flow ducts is described. The Grazing Flow Impedance Tube only supports plane-wave sources, while the Curved Duct Test Rig supports sources that contain higher-order modes. Multiple exercises are used to validate this new impedance eduction method. First, synthesized data for a hard wall insert and a conventional liner mounted in the Grazing Flow Impedance Tube are used as input to the two impedance eduction methods, the pressure gradient method and a previously validated wall pressure method. Comparisons between the two results are excellent. Next, data measured in the Grazing Flow Impedance Tube are used as input to both methods. Results from the two methods compare quite favorably for sufficiently low Mach numbers but this comparison degrades at Mach 0.5, especially when the hard wall insert is used. Finally, data measured with a hard wall insert mounted in the Curved Duct Test Rig are used as input to the pressure gradient method. Significant deviation from the known solution is observed, which is believed to be largely due to 3-D effects in this flow duct. Potential solutions to this issue are currently being explored.

  1. Development on electromagnetic impedance function modeling and its estimation

    NASA Astrophysics Data System (ADS)

    Sutarno, D.

    2015-09-01

    Today the Electromagnetic methods such as magnetotellurics (MT) and controlled sources audio MT (CSAMT) is used in a broad variety of applications. Its usefulness in poor seismic areas and its negligible environmental impact are integral parts of effective exploration at minimum cost. As exploration was forced into more difficult areas, the importance of MT and CSAMT, in conjunction with other techniques, has tended to grow continuously. However, there are obviously important and difficult problems remaining to be solved concerning our ability to collect process and interpret MT as well as CSAMT in complex 3D structural environments. This talk aim at reviewing and discussing the recent development on MT as well as CSAMT impedance functions modeling, and also some improvements on estimation procedures for the corresponding impedance functions. In MT impedance modeling, research efforts focus on developing numerical method for computing the impedance functions of three dimensionally (3-D) earth resistivity models. On that reason, 3-D finite elements numerical modeling for the impedances is developed based on edge element method. Whereas, in the CSAMT case, the efforts were focused to accomplish the non-plane wave problem in the corresponding impedance functions. Concerning estimation of MT and CSAMT impedance functions, researches were focused on improving quality of the estimates. On that objective, non-linear regression approach based on the robust M-estimators and the Hilbert transform operating on the causal transfer functions, were used to dealing with outliers (abnormal data) which are frequently superimposed on a normal ambient MT as well as CSAMT noise fields. As validated, the proposed MT impedance modeling method gives acceptable results for standard three dimensional resistivity models. Whilst, the full solution based modeling that accommodate the non-plane wave effect for CSAMT impedances is applied for all measurement zones, including near-, transition

  2. Development on electromagnetic impedance function modeling and its estimation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sutarno, D., E-mail: Sutarno@fi.itb.ac.id

    2015-09-30

    Today the Electromagnetic methods such as magnetotellurics (MT) and controlled sources audio MT (CSAMT) is used in a broad variety of applications. Its usefulness in poor seismic areas and its negligible environmental impact are integral parts of effective exploration at minimum cost. As exploration was forced into more difficult areas, the importance of MT and CSAMT, in conjunction with other techniques, has tended to grow continuously. However, there are obviously important and difficult problems remaining to be solved concerning our ability to collect process and interpret MT as well as CSAMT in complex 3D structural environments. This talk aim atmore » reviewing and discussing the recent development on MT as well as CSAMT impedance functions modeling, and also some improvements on estimation procedures for the corresponding impedance functions. In MT impedance modeling, research efforts focus on developing numerical method for computing the impedance functions of three dimensionally (3-D) earth resistivity models. On that reason, 3-D finite elements numerical modeling for the impedances is developed based on edge element method. Whereas, in the CSAMT case, the efforts were focused to accomplish the non-plane wave problem in the corresponding impedance functions. Concerning estimation of MT and CSAMT impedance functions, researches were focused on improving quality of the estimates. On that objective, non-linear regression approach based on the robust M-estimators and the Hilbert transform operating on the causal transfer functions, were used to dealing with outliers (abnormal data) which are frequently superimposed on a normal ambient MT as well as CSAMT noise fields. As validated, the proposed MT impedance modeling method gives acceptable results for standard three dimensional resistivity models. Whilst, the full solution based modeling that accommodate the non-plane wave effect for CSAMT impedances is applied for all measurement zones, including near

  3. Time-Domain Impedance Boundary Conditions for Computational Aeroacoustics

    NASA Technical Reports Server (NTRS)

    Tam, Christopher K. W.; Auriault, Laurent

    1996-01-01

    It is an accepted practice in aeroacoustics to characterize the properties of an acoustically treated surface by a quantity known as impedance. Impedance is a complex quantity. As such, it is designed primarily for frequency-domain analysis. Time-domain boundary conditions that are the equivalent of the frequency-domain impedance boundary condition are proposed. Both single frequency and model broadband time-domain impedance boundary conditions are provided. It is shown that the proposed boundary conditions, together with the linearized Euler equations, form well-posed initial boundary value problems. Unlike ill-posed problems, they are free from spurious instabilities that would render time-marching computational solutions impossible.

  4. Socio-economic factors, health care consumption and rating of abdominal symptom severity. A report from the abdominal symptom study.

    PubMed

    Agréus, L

    1993-06-01

    A study of the abdominal/gastrointestinal symptom panorama in relation to socio-economic factors and health care consumption in the general population was performed in Osthammar, Sweden. A postal questionnaire was sent to a representative sample of the adult population (n = 1260). The response rate was 87%. The responders with symptoms (52.1%) subjectively rated their illness on visual analogue scales. All responders were classified as asymptomatic or having 'minor' or 'major' abdominal symptoms. Those having dyspepsia, reflux or irritable bowel syndrome were also ranked as 'minors' or 'majors'. The proportion of subjects with abdominal/gastrointestinal complaints decreased with age, mainly due to a decrease of 'major' symptoms. Also, the proportion of complainers increased among the more educated. Those on sick leave and students had more and worse symptoms than the others, despite the former seldom stating abdominal discomfort as the main reason for sick listing. Fifty-five per cent of all persons reporting abdominal/gastrointestinal symptoms had at some time consulted a doctor because of such complaints, the proportion increasing with severity, as did drug consumption and the rate of previous abdominal operations, with appendectomy as an exception. The results show that it is possible to rank the illness along a severity dimension among persons with abdominal/gastrointestinal complaints in epidemiological research.

  5. Impedance measurement using a two-microphone, random-excitation method

    NASA Technical Reports Server (NTRS)

    Seybert, A. F.; Parrott, T. L.

    1978-01-01

    The feasibility of using a two-microphone, random-excitation technique for the measurement of acoustic impedance was studied. Equations were developed, including the effect of mean flow, which show that acoustic impedance is related to the pressure ratio and phase difference between two points in a duct carrying plane waves only. The impedances of a honeycomb ceramic specimen and a Helmholtz resonator were measured and compared with impedances obtained using the conventional standing-wave method. Agreement between the two methods was generally good. A sensitivity analysis was performed to pinpoint possible error sources and recommendations were made for future study. The two-microphone approach evaluated in this study appears to have some advantages over other impedance measuring techniques.

  6. [Internationalization and innovation of abdominal acupuncture].

    PubMed

    Wang, Yong-Zhou

    2013-09-01

    Characteristics of abdominal acupuncture are analyzed through three aspects of inheriting and innovation, collaborated research as well as international visual field. It is pointed that abdominal acupuncture is based on clinical practice, focuses on enhancing the therapeutic effect and expending the clinical application. It also promots the thinking on how to recall the tradition and how to inherit tradition availably. The modern medical problems should be studied and innovation resolutions should be searched, which can help the internationalization and modernization of abdominal acupuncture.

  7. Plasma Diagnostics by Antenna Impedance Measurements

    NASA Technical Reports Server (NTRS)

    Swenson, C. M.; Baker, K. D.; Pound, E.; Jensen, M. D.

    1993-01-01

    The impedance of an electrically short antenna immersed in a plasma provides an excellent in situ diagnostic tool for electron density and other plasma parameters. By electrically short we mean that the wavelength of the free-space electromagnetic wave that would be excited at the driving frequency is much longer than the physical size of the antenna. Probes using this impedance technique have had a long history with sounding rockets and satellites, stretching back to the early 1960s. This active technique could provide information on composition and temperature of plasmas for comet or planetary missions. Advantages of the impedance probe technique are discussed and two classes of instruments built and flown by SDL-USU for determining electron density (the capacitance and plasma frequency probes) are described.

  8. Impedance properties of circular microstrip antenna

    NASA Technical Reports Server (NTRS)

    Deshpande, M. D.; Bailey, M. C.

    1983-01-01

    A moment method solution to the input impedance of a circular microstrip antenna excited by either a microstrip feed or a coaxial probe is presented. Using the exact dyadic Green's function and the Fourier transform the problem is formulated in terms of Richmond's reaction integral equation from which the unknown patch current can be solved for. The patch current is expanded in terms of regular surface patch modes and an attachment mode (for probe excited case) which insures continuity of the current at probe/patch junction, proper polarization and p-dependance of patch current in the vicinity of the probe. The input impedance of a circular microstrip antenna is computed and compared with earlier results. Effect of attachment mode on the input impedance is also discussed.

  9. Elasticity of the living abdominal wall in laparoscopic surgery.

    PubMed

    Song, Chengli; Alijani, Afshin; Frank, Tim; Hanna, George; Cuschieri, Alfred

    2006-01-01

    Laparoscopic surgery requires inflation of the abdominal cavity and this offers a unique opportunity to measure the mechanical properties of the living abdominal wall. We used a motion analysis system to study the abdominal wall motion of 18 patients undergoing laparoscopic surgery, and found that the mean Young's modulus was 27.7+/-4.5 and 21.0+/-3.7 kPa for male and female, respectively. During inflation, the abdominal wall changed from a cylinder to a dome shape. The average expansion in the abdominal wall surface was 20%, and a working space of 1.27 x 10(-3)m(3) was created by expansion, reshaping of the abdominal wall and diaphragmatic movement. For the first time, the elasticity of human abdominal wall was obtained from the patients undergoing laparoscopic surgery, and a 3D simulation model of human abdominal wall has been developed to analyse the motion pattern in laparoscopic surgery. Based on this study, a mechanical abdominal wall lift and a surgical simulator for safe/ergonomic port placements are under development.

  10. Application of plant impedance for diagnosing plant disease

    NASA Astrophysics Data System (ADS)

    Xu, Huirong; Jiang, Xuesong; Zhu, Shengpan; Ying, Yibin

    2006-10-01

    Biological cells have components acting as electrical elements that maintain the health of the cell by regulation of the electrical charge content. Plant impedance is decided by the state of plant physiology and pathology. Plant physiology and pathology can be studies by measuring plant impedance. The effect of Cucumber Mosaic Virus red bean isolate (CMV-RB) on electrical resistance of tomato leaves was studied by the method of impedance measurement. It was found that the value of resistance of tomato leaves infected with CMV-RB was smaller than that in sound plant leaves. This decrease of impedances in leaf tissue was occurred with increased severity of disease. The decrease of resistance of tomato leaves infected with CMV-RB could be detected by electrical resistance detecting within 4 days after inoculation even though significant visible differences between the control and the infected plants were not noted, so that the technique for measurement of tomato leaf tissue impedance is a rapid, clever, simple method on diagnosis of plant disease.

  11. Possibilities of electrical impedance tomography in gynecology

    NASA Astrophysics Data System (ADS)

    V, Trokhanova O.; A, Chijova Y.; B, Okhapkin M.; V, Korjenevsky A.; S, Tuykin T.

    2013-04-01

    The paper describes results of comprehensive EIT diagnostics of mammary glands and cervix. The data were obtained from examinations of 170 patients by EIT system MEM (multi-frequency electrical impedance mammograph) and EIT system GIT (gynecological impedance tomograph). Mutual dependence is discussed.

  12. Microelectrical Impedance Spectroscopy for the Differentiation between Normal and Cancerous Human Urothelial Cell Lines: Real-Time Electrical Impedance Measurement at an Optimal Frequency

    PubMed Central

    Park, Yangkyu; Kim, Hyeon Woo; Yun, Joho; Seo, Seungwan; Park, Chang-Ju; Lee, Jeong Zoo; Lee, Jong-Hyun

    2016-01-01

    Purpose. To distinguish between normal (SV-HUC-1) and cancerous (TCCSUP) human urothelial cell lines using microelectrical impedance spectroscopy (μEIS). Materials and Methods. Two types of μEIS devices were designed and used in combination to measure the impedance of SV-HUC-1 and TCCSUP cells flowing through the channels of the devices. The first device (μEIS-OF) was designed to determine the optimal frequency at which the impedance of two cell lines is most distinguishable. The μEIS-OF trapped the flowing cells and measured their impedance at a frequency ranging from 5 kHz to 1 MHz. The second device (μEIS-RT) was designed for real-time impedance measurement of the cells at the optimal frequency. The impedance was measured instantaneously as the cells passed the sensing electrodes of μEIS-RT. Results. The optimal frequency, which maximized the average difference of the amplitude and phase angle between the two cell lines (p < 0.001), was determined to be 119 kHz. The real-time impedance of the cell lines was measured at 119 kHz; the two cell lines differed significantly in terms of amplitude and phase angle (p < 0.001). Conclusion. The μEIS-RT can discriminate SV-HUC-1 and TCCSUP cells by measuring the impedance at the optimal frequency determined by the μEIS-OF. PMID:26998490

  13. Abdominal pain - children under age 12

    MedlinePlus

    Stomach pain in children; Pain - abdomen - children; Abdominal cramps in children; Belly ache in children ... When your child complains of abdominal pain, see if they can describe it to you. Here are different kinds of pain: ...

  14. [The functional assessment of the upper urinary tract by the methods of 2-frequency impedance measurement and multichannel impedance ureterography].

    PubMed

    Mudraia, I S; Kirpatovskiĭ, V I

    1993-01-01

    The paper describes impedance methods of investigating upper urinary tracts (UUT) which may serve adjuvants in the diagnosis of the urinary tract wall disturbances due to diseases caused by impaired urine evacuation from the kidney and which may prove helpful in the choice of therapeutic policy, evaluation of the postoperative period and outcomes prognosis. UUT impedance tests can be performed during endoscopic manipulations or under open operative interventions. Two-frequency impedancemetry allows rapid detection of non-functioning UUT parts or sclerosal sites of the UUT wall, relevant criteria being the ratio of basic impedances of the site under low and high scanning current. This value is computed by an urological two-frequency impedancemeter IDU-M. To assess the UUT wall functionally, use should be made of 6-channel urological rheograph REUR-6 providing multichannel registration of immediate impedance ureterograms. In this manner one can obtain qualitative and quantitative assessment of the ureteral peristalsis through its all length, the criteria being the amplitude of impedance ureterographic complexes, their shape, duration, frequency, rhythm, sequence and rate of distribution. Loading tests increase the accuracy of UUT impedance measurements, are able to define compensatory reserves of the wall contractility. The introduction of rheological methods in urological practice makes broader the armory of diagnostic techniques in urology, upgrade pathogenetic validity of surgical and therapeutic measures.

  15. Enhancement of extracellular electron transfer and bioelectricity output by synthetic porin.

    PubMed

    Yong, Yang-Chun; Yu, Yang-Yang; Yang, Yun; Liu, Jing; Wang, Jing-Yuan; Song, Hao

    2013-02-01

    The microbial fuel cell (MFC), is a promising environmental biotechnology for harvesting electricity energy from organic wastes. However, low bacterial membrane permeability of electron shuttles is a limiting factor that restricts the electron shuttle-mediated extracellular electron transfer (EET) from bacteria to electrodes, thus the electricity power output of MFCs. To this end, we heterologously expressed a porin protein OprF from Pseudomonas aeruginosa PAO1 into Escherichia coli, which dramatically increased its membrane permeability, delivering a much higher current output in MFCs than its parental strain (BL21). We found that the oprF-expression strain showed more efficient EET than its parental strain. More strikingly, the enhanced membrane permeability also rendered the oprF-expression strain an efficient usage of riboflavin as the electron shuttle, whereas its parental strain was incapable of. Our results substantiated that membrane permeability is crucial for the efficient EET, and indicated that the expression of synthetic porins could be an efficient strategy to enhance bioelectricity generation by microorganisms (including electrogenic bacteria) in MFCs. Copyright © 2012 Wiley Periodicals, Inc.

  16. Clinical implementation of electrical impedance tomography with hyperthermia.

    PubMed

    Moskowitz, M J; Ryan, T P; Paulsen, K D; Mitchell, S E

    1995-01-01

    We describe the use of electrical impedance tomography (EIT) for non-invasive thermal imaging in conjunction with a clinical treatment of a superficial scalp lesion utilizing a spiral microstrip antenna. This is our first reported use of EIT with a clinical hyperthermia treatment and perhaps the first world-wide. The thermal measurements recorded during treatment compare favourably with the images reconstructed from impedance data gathered during heating. A linear relation, measured in phantom material, between the change in temperature with the change in reconstructed impedance was assumed. The average discrepancy between the measured temperature changes with the temperatures reconstructed from the impedance changes was 1.4 degrees C, with the maximum being 8.9 degrees C. These preliminary data suggest that impedance changes can be measured during hyperthermia delivery and temperature estimates based on these observed changes are possible in the clinical setting. These findings also point to the complex, yet critical nature of the impedance versus temperature relationship for tissue in vivo. The reconstructed thermal images may provide complementary information about the overall thermal damage imposed during heating. Based on this initial clinical experience we feel that EIT has great potential as a viable clinical aid in imaging the temperature changes imposed during hyperthermia.

  17. Impedance dispersion analysis of drug-membrane interactions

    NASA Astrophysics Data System (ADS)

    Tacheva, Bilyana; Paarvanova, Boyana; Ivanov, Ivan T.; Karabaliev, Miroslav

    2017-11-01

    Thin lipid films modified glassy carbon electrodes (GCE) were used in this work as model system for studying the interactions between two antipsychotic phenothiazine drugs, chlorpromazine and thioridazine, and the lipid fraction of the biomembranes. The lipid films on the electrode surface were obtained through the thinning of film-forming lipid solution deposited between an electrolyte phase and the working GC electrode. The effects of the drugs on the lipid film structure were investigated by electrochemical impedance spectroscopy (EIS). To characterize the electric properties of the lipid film the impedance of the working GCE is modeled with an equivalent circuit consisting of parallel capacitance Cp and resistance Rp. These capacitance and resistance are not frequency independent but could be calculated as equivalent Cp and Rp for each measured frequency of the impedance spectrum and presented as functions of the frequency f, Cp = Cp(f) and Rp= Rp(f). For the lipid films used in this work, it is demonstrated that both Cp(f) and Rp(f) are well approximated with power-law functions. This behavior implies that the impedance Z of the films could be analysed in terms of the well-known constant-phase angle element (CPE), which is often used to describe the interfacial impedance of solid working electrodes.

  18. Intra-abdominal pressure: an integrative review.

    PubMed

    Milanesi, Rafaela; Caregnato, Rita Catalina Aquino

    2016-01-01

    There is a growing request for measuring intra-abdominal pressure in critically ill patients with acute abdominal pain to be clarified. Summarizing the research results on measurement of vesical intra-abdominal pressure and analyzing the level of evidence were the purposes of this integrative literature review, carried out based on the databases LILACS, MEDLINE and PubMed, from 2005 to July 2012. Twenty articles were identified, in that, 12 literature reviews, 4 descriptive and exploratory studies, 2 expert opinions, one prospective cohort study and one was an experience report. The vesical intra-abdominal pressure measurement was considered gold standard. There are variations in the technique however, but some common points were identified: complete supine position, in absence of abdominal contracture, in the end of expiration and expressed in mmHg. Most research results indicate keeping the transducer zeroed at the level of the mid-axillary line at the iliac crest level, and instill 25mL of sterile saline. Strong evidence must be developed. RESUMO Em pacientes críticos com quadros abdominais agudos a esclarecer é crescente a solicitação da aferição da pressão intra-abdominal. Sintetizar resultados de pesquisas sobre a mensuração da pressão intra-abdominal pela via vesical e analisar o nível de evidência foram os objetivos desta revisão integrativa da literatura, realizada nas bases LILACS, MEDLINE e PubMed, no período de 2005 a julho de 2012. Identificaram-se 20 artigos, sendo 12 revisões de literatura, 4 estudos exploratório-descritivos, 2 opiniões de especialistas, 1 estudo de coorte prospectivo e 1 relato de experiência. O método vesical para mensuração da pressão intra-abdominal foi considerado padrão-ouro. Existem variações na técnica, entretanto pontos em comum foram identificados: posição supina completa, na ausência de contratura abdominal, ao final da expiração e expressa em mmHg. A maioria indica posicionar o ponto zero do

  19. Abdomino-phrenic dyssynergia in patients with abdominal bloating and distension.

    PubMed

    Villoria, Albert; Azpiroz, Fernando; Burri, Emanuel; Cisternas, Daniel; Soldevilla, Alfredo; Malagelada, Juan-R

    2011-05-01

    The abdomen normally accommodates intra-abdominal volume increments. Patients complaining of abdominal distension exhibit abnormal accommodation of colonic gas loads (defective contraction and excessive protrusion of the anterior wall). However, abdominal imaging demonstrated diaphragmatic descent during spontaneous episodes of bloating in patients with functional gut disorders. We aimed to establish the role of the diaphragm in abdominal distension. In 20 patients complaining of abdominal bloating and 15 healthy subjects, we increased the volume of the abdominal cavity with a colonic gas load, while measuring abdominal girth and electromyographic activity of the anterior abdominal muscles and of the diaphragm. In healthy subjects, the colonic gas load increased girth, relaxed the diaphragm, and increased anterior wall tone. With the same gas load, patients developed significantly more abdominal distension; this was associated with paradoxical contraction of the diaphragm and relaxation of the internal oblique muscle. In this experimental provocation model, abnormal accommodation of the diaphragm is involved in abdominal distension.

  20. PREFACE: XV International Conference on Electrical Bio-Impedance (ICEBI) & XIV Conference on Electrical Impedance Tomography (EIT)

    NASA Astrophysics Data System (ADS)

    Pliquett, Uwe

    2013-04-01

    Over recent years advanced measurement methods have facilitated outstanding achievements not only in medical instrumentation but also in biotechnology. Impedance measurement is a simple and innocuous way to characterize materials. For more than 40 years biological materials, most of them based on cells, have been characterized by means of electrical impedance for quality control of agricultural products, monitoring of biotechnological or food processes or in health care. Although the list of possible applications is long, very few applications successfully entered the market before the turn of the century. This was, on the one hand, due to the low specificity of electrical impedance with respect to other material properties because it is influenced by multiple factors. On the other hand, equipment and methods for many potential applications were not available. With the appearance of microcontrollers that could be easily integrated in applications at the beginning of the 1980s, impedance measurement advanced as a valuable tool in process optimization and lab automation. However, established methods and data processing were mostly used in a new environment. This has changed significantly during the last 10 years with a dramatic growth of the market for medical instrumentation and also for biotechnological applications. Today, advanced process monitoring and control require fast and highly parallel electrical characterization which in turn yields incredible data volumes that must be handled in real time. Many newer developments require miniaturized but precise sensing methods which is one of the main parts of Lab-on-Chip technology. Moreover, biosensors increasingly use impedometric transducers, which are not compatible with the large expensive measurement devices that are common in the laboratory environment. Following the achievements in the field of bioimpedance measurement, we will now witness a dramatic development of new electrode structures and electronics

  1. AC impedance investigations of proton conduction in Nafion(sup TM)

    NASA Astrophysics Data System (ADS)

    Cahan, B. D.; Wainright, J. S.

    1993-12-01

    AC impedance spectroscopy has been employed to study the conduction of protons in Nafion 117 polymer electrolyte membrane. Both two- and four-electrode geometries have been used to uniquely distinguish between the membrane impedance and the interfacial impedances. The results show that the impedance of Nafion for frequencies up to 100 kHz is characterized by a pure resistance, similar to conventional liquid electrolytes. The frequency dependent features observed using a two-electrode geometry are shown to be consistent will well-characterized interfacial impedances and do not arise from ionic conduction in the membrane. These results show that previous two-electrode studies reported in the literature have misinterpreted the impedance of the electrode interfaces as belonging to the conduction process in the electrolyte.

  2. Segmentation of images of abdominal organs.

    PubMed

    Wu, Jie; Kamath, Markad V; Noseworthy, Michael D; Boylan, Colm; Poehlman, Skip

    2008-01-01

    Abdominal organ segmentation, which is, the delineation of organ areas in the abdomen, plays an important role in the process of radiological evaluation. Attempts to automate segmentation of abdominal organs will aid radiologists who are required to view thousands of images daily. This review outlines the current state-of-the-art semi-automated and automated methods used to segment abdominal organ regions from computed tomography (CT), magnetic resonance imaging (MEI), and ultrasound images. Segmentation methods generally fall into three categories: pixel based, region based and boundary tracing. While pixel-based methods classify each individual pixel, region-based methods identify regions with similar properties. Boundary tracing is accomplished by a model of the image boundary. This paper evaluates the effectiveness of the above algorithms with an emphasis on their advantages and disadvantages for abdominal organ segmentation. Several evaluation metrics that compare machine-based segmentation with that of an expert (radiologist) are identified and examined. Finally, features based on intensity as well as the texture of a small region around a pixel are explored. This review concludes with a discussion of possible future trends for abdominal organ segmentation.

  3. Abdominal Pain in the Geriatric Patient.

    PubMed

    Leuthauser, Amy; McVane, Benjamin

    2016-05-01

    Abdominal pain in the elderly can be a challenging and difficult condition to diagnose and treat. The geriatric population has significant comorbidities and often takes polypharmacy that can mask symptoms. The presentation of common conditions can be different than that in the younger population, often lacking the traditional indicators of disease, making it of pivotal importance for the clinician to consider a wide differential during their workup. It is also important to consider extra-abdominal abnormality that may manifest as abdominal pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Abdominal pain in children with sickle cell disease.

    PubMed

    Rhodes, Melissa M; Bates, David Gregory; Andrews, Tina; Adkins, Laura; Thornton, Jennifer; Denham, Jolanda M

    2014-02-01

    The differential diagnosis of abdominal pain is broad in any child, and further complicated in children with sickle cell disease (SCD). Acute causes of abdominal pain may require emergent surgery, such as for appendicitis or obstruction caused by a bezoar. Rapid intervention is necessary and life-saving in children with SCD and acute splenic or hepatic sequestration. The majority of children with SCD presenting to the physician's office or emergency department will have subacute reasons for their abdominal pain, including but not limited to constipation, urinary tract infection, peptic ulcer disease, and cholecystitis. Vaso-occlusive pain often presents in children as abdominal pain, but is a diagnosis of exclusion. The case of a 10-year-old girl with intermittent abdominal pain is used as a starting point to review the pathophysiology, diagnosis, and treatment of the most acute and common causes of abdominal pain in children with SCD.

  5. Compliance of the abdominal wall during laparoscopic insufflation.

    PubMed

    Becker, Chuck; Plymale, Margaret A; Wennergren, John; Totten, Crystal; Stigall, Kyle; Roth, J Scott

    2017-04-01

    To provide adequate workspace between the viscera and abdominal wall, insufflation with carbon dioxide is a common practice in laparoscopic surgeries. An insufflation pressure of 15 mmHg is considered to be safe in patients, but all insufflation pressures create perioperative and postoperative physiologic effects. As a composition of viscoelastic materials, the abdominal wall should distend in a predictable manner given the pressure of the pneumoperitoneum. The purpose of this study was to elucidate the relationship between degree of abdominal distention and the insufflation pressure, with the goal of determining factors which impact the compliance of the abdominal wall. A prospective, IRB-approved study was conducted to video record the abdomens of patients undergoing insufflation prior to a laparoscopic surgery. Photo samples were taken every 5 s, and the strain of the patient's abdomen in the sagittal plane was determined, as well as the insufflator pressure (stress) at bedside. Patients were insufflated to 15 mmHg. The relationship between the stress and strain was determined in each sample, and compliance of the patient's abdominal wall was calculated. Subcutaneous fat thickness and rectus abdominus muscle thickness were obtained from computed tomography scans. Correlations between abdominal wall compliances and subcutaneous fat and muscle content were determined. Twenty-five patients were evaluated. An increased fat thickness in the abdominal wall had a direct exponential relationship with abdominal wall compliance (R 2  = 0.59, p < 0.05). There was no correlation between muscle and fat thickness. All insufflation pressures create perioperative and postoperative complications. The compliance of patients' abdominal body walls differs, and subcutaneous fat thickness has a direct exponential relationship with abdominal wall compliance. Thus, insufflation pressures can be better tailored per the patient. Future studies are needed to demonstrate the

  6. Abdominal pregnancy - Case presentation.

    PubMed

    Bohiltea, R; Radoi, V; Tufan, C; Horhoianu, I A; Bohiltea, C

    2015-01-01

    Abdominal pregnancy, a rare diagnosis, belongs to the ectopic pregnancy group, the leading cause of pregnancy related exitus. The positive diagnosis is very difficult to establish most often in an acute setting, leading to a staggering percent of feto-maternal morbidity and mortality. We present the case of 26-weeks-old abdominal pregnancy with partial feto-placental detachment in a patient, after hysteroscopy and in vitro fertilization, which until the acute symptoms that led to emergency laparotomy went unrecognized. The patient recovered completely and satisfactorily after surgery and, due to the high risk of uterine rupture with regard to a second pregnancy, opted for a surrogate mother. Abdominal pregnancy can be regarded as a difficult to establish diagnosis, with a greater chance in case of increased awareness. It is compulsory to be well informed in order not to be surprised by the diagnosis and to apply the correct treatment immediately as the morbidity and mortality rate is elevated.

  7. Treatment strategy for ruptured abdominal aortic aneurysms.

    PubMed

    Davidovic, L

    2014-07-01

    Rupture is the most serious and lethal complication of the abdominal aortic aneurysm. Despite all improvements during the past 50 years, ruptured abdominal aortic aneurysms are still associated with very high mortality. Namely, including patients who die before reaching the hospital, the mortality rate due to abdominal aortic aneurysm rupture is 90%. On the other hand, during the last twenty years, the number of abdominal aortic aneurysms significantly increased. One of the reasons is the fact that in majority of countries the general population is older nowadays. Due to this, the number of degenerative AAA is increasing. This is also the case for patients with abdominal aortic aneurysm rupture. Age must not be the reason of a treatment refusal. Optimal therapeutic option ought to be found. The following article is based on literature analysis including current guidelines but also on my Clinics significant experience. Furthermore, this article show cases options for vascular medicine in undeveloped countries that can not apply endovascular procedures at a sufficient level and to a sufficient extent. At this moment the following is evident. Thirty-day-mortality after repair of ruptured abdominal aortic aneurysms is significantly lower in high-volume hospitals. Due to different reasons all ruptured abdominal aortic aneurysms are not suitable for EVAR. Open repair of ruptured abdominal aortic aneurysm should be performed by experienced open vascular surgeons. This could also be said for the treatment of endovascular complications that require open surgical conversion. There is no ideal procedure for the treatment of AAA. Each has its own advantages and disadvantages, its own limits and complications, as well as indications and contraindications. Future reductions in mortality of ruptured abdominal aortic aneurysms will depend on implementation of population-based screening; on strategies to prevent postoperative organ injury and also on new medical technology

  8. Computed tomographic evaluation of abdominal fat in minipigs.

    PubMed

    Chang, Jinhwa; Jung, Joohyun; Lee, Hyeyeon; Chang, Dongwoo; Yoon, Junghee; Choi, Mincheol

    2011-03-01

    Computed tomography (CT) exams were conducted to determine the distribution of abdominal fat identified based on the CT number measured in Hounsfield Units (HU) and to measure the volume of the abdominal visceral and subcutaneous fat in minipigs. The relationship between the CT-based fat volumes of several vertebral levels and the entire abdomen and anthropometric data including the sagittal abdominal diameter and waist circumference were evaluated. Moreover, the total fat volumes at the T11, T13, L3, and L5 levels were compared with the total fat volume of the entire abdomen to define the landmark of abdominal fat distribution. Using a single-detector CT, six 6-month-old male minipigs were scanned under general anesthesia. Three radiologists then assessed the HU value of visceral and subcutaneous abdominal fat by drawing the region of interest manually at the T11, T13, L1, L3, and L5 levels. The CT number and abdominal fat determined in this way by the three radiologists was found to be correlated (intra-class coefficient = 0.9). The overall HU ranges for the visceral and subcutaneous fat depots were -147.47 to -83.46 and -131.62 to -90.97, respectively. The total fat volume of the entire abdomen was highly correlated with the volume of abdominal fat at the T13 level (r = 0.97, p < 0.0001). These findings demonstrate that the volume of abdominal adipose tissue measured at the T13 level using CT is a strong and reliable predictor of total abdominal adipose volume.

  9. [Abdominal catastrophe--abdominal wall defect associated with gastrointestinal fistula--strategy of therapy].

    PubMed

    Chobola, M; Sobotka, L; Ferko, A; Oberreiter, M; Kaska, M; Motycka, V; Páral, J; Mottl, R

    2010-11-01

    Wound dehiscence complicated by gastrointestinal (GI) fistula to belong ,,abdominal catastrophe". Therapy is prolonged and connected with high morbidity and mortality rate. In the period from October 2006 to July 2009 we performed 12 reconstructive surgical procedures on gastrointestinal tract in patients with abdominal catastrophe. Treatment of 12 consecutive patients (9 men, 3 women) was managed according to a standardize protocol. The protocol consists of treatment of septic complications, optimisation of nutritional state, special wound procedures, diagnosis of gastrointestinal fistulas and GI tract, timing of surgical procedures, reconstruction of GI tract and postoperative care. Reconstructive surgery of GI tract was successful on 11 patients. One patient developed recurrence of early GI fistula. In four patients we let open abdomen to heal per secundam. We observed no deaths after operation. With regard to complex character of therapy of abdominal catastrophe there is a need of multidisciplinary approach. Considering long-lasting and expensive therapy there is logical step to concentrate these patients into special centres which are experienced, equipped and their staff is trained in treatment of such a seriously impaired patients.

  10. Electrical impedance tomography

    PubMed Central

    Lobo, Beatriz; Hermosa, Cecilia; Abella, Ana

    2018-01-01

    Continuous assessment of respiratory status is one of the cornerstones of modern intensive care unit (ICU) monitoring systems. Electrical impedance tomography (EIT), although with some constraints, may play the lead as a new diagnostic and guiding tool for an adequate optimization of mechanical ventilation in critically ill patients. EIT may assist in defining mechanical ventilation settings, assess distribution of tidal volume and of end-expiratory lung volume (EELV) and contribute to titrate positive end-expiratory pressure (PEEP)/tidal volume combinations. It may also quantify gains (recruitment) and losses (overdistention or derecruitment), granting a more realistic evaluation of different ventilator modes or recruitment maneuvers, and helping in the identification of responders and non-responders to such maneuvers. Moreover, EIT also contributes to the management of life-threatening lung diseases such as pneumothorax, and aids in guiding fluid management in the critical care setting. Lastly, assessment of cardiac function and lung perfusion through electrical impedance is on the way. PMID:29430443

  11. Abdominal rigidity

    MedlinePlus

    ... other symptoms do you have at the same time? For example, do you have abdominal pain ? You may have the following tests: Barium studies of the stomach and intestines (such as an upper GI series ) Blood tests Colonoscopy Gastroscopy Peritoneal lavage Stool studies ...

  12. Entrance and Exit CSR Impedance for Non-Ultrarelativistic Beam

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Rui; Tsai, Cheng Ying

    2017-05-01

    For a high-brightness electron beam being transported through beamlines involving bending systems, the coherent synchrotron radiation (CSR) and longitudinal space charge (LSC) interaction could often cause microbunching instability. The semi-analytical Vlasov solver for microbunching gain* depends on the impedances for the relevant collective effects. The existing results for CSR impedances are usually obtained for the ultrarelativistic limit. To extend the microbunching analysis to cases of low energies, such as the case of an ERL merger, or to density modulations at extremely small wavelength, it is necessary to extend the impedance analysis to the non-ultrarelativistic regime. In this study, we presentmore » the impedance analysis for the transient CSR interaction in the non-ultrarelativistic regime, for transients including both entrance to and exit from a magnetic dipole. These impedance results will be compared to their ultra-relativistic counterparts**, and the corresponding wakefield obtained from the impedance for low-energy beams will be compared with the existing results of transient CSR wakefield for general beam energies***.« less

  13. Using surface impedance for calculating wakefields in flat geometry

    DOE PAGES

    Bane, Karl; Stupakov, Gennady

    2015-03-18

    Beginning with Maxwell's equations and assuming only that the wall interaction can be approximated by a surface impedance, we derive formulas for the generalized longitudinal and transverse impedance in flat geometry, from which the wakefields can also be obtained. From the generalized impedances, by taking the proper limits, we obtain the normal longitudinal, dipole, and quad impedances in flat geometry. These equations can be applied to any surface impedance, such as the known dc, ac, and anomalous skin models of wall resistance, a model of wall roughness, or one for a pipe with small, periodic corrugations. We show that, formore » the particular case of dc wall resistance, the longitudinal impedance obtained here agrees with a known result in the literature, a result that was derived from a very general formula by Henke and Napoly. As an example, we apply our results to representative beam and machine parameters in the undulator region of LCLS-II and estimate the impact of the transverse wakes on the machine performance.« less

  14. Uncertainty Analysis of the Grazing Flow Impedance Tube

    NASA Technical Reports Server (NTRS)

    Brown, Martha C.; Jones, Michael G.; Watson, Willie R.

    2012-01-01

    This paper outlines a methodology to identify the measurement uncertainty of NASA Langley s Grazing Flow Impedance Tube (GFIT) over its operating range, and to identify the parameters that most significantly contribute to the acoustic impedance prediction. Two acoustic liners are used for this study. The first is a single-layer, perforate-over-honeycomb liner that is nonlinear with respect to sound pressure level. The second consists of a wire-mesh facesheet and a honeycomb core, and is linear with respect to sound pressure level. These liners allow for evaluation of the effects of measurement uncertainty on impedances educed with linear and nonlinear liners. In general, the measurement uncertainty is observed to be larger for the nonlinear liners, with the largest uncertainty occurring near anti-resonance. A sensitivity analysis of the aerodynamic parameters (Mach number, static temperature, and static pressure) used in the impedance eduction process is also conducted using a Monte-Carlo approach. This sensitivity analysis demonstrates that the impedance eduction process is virtually insensitive to each of these parameters.

  15. Abdominal exploration - slideshow

    MedlinePlus

    ... ency/presentations/100049.htm Abdominal exploration - series—Normal ... intestine (jejunum and ileum), the large intestine (colon), the liver, the spleen, the gallbladder, the pancreas, the uterus, ...

  16. Successful Treatment of Abdominal Cutaneous Entrapment Syndrome Using Ultrasound Guided Injection

    PubMed Central

    Hong, Myong Joo; Seo, Dong Hyuk

    2013-01-01

    There are various origins for chronic abdominal pain. About 10-30% of patients with chronic abdominal pain have abdominal wall pain. Unfortunately, abdominal wall pain is not thought to be the first origin of chronic abdominal pain; therefore, patients usually undergo extensive examinations, including diagnostic laparoscopic surgery. Entrapment of abdominal cutaneous nerves at the muscular foramen of the rectus abdominis is a rare cause of abdominal wall pain. If abdominal wall pain is considered in earlier stage of chronic abdominal pain, unnecessary invasive procedures are not required and patients will reach symptom free condition as soon as the diagnosis is made. Here, we report a case of successful treatment of a patient with abdominal cutaneous nerve entrapment syndrome by ultrasound guided injection therapy. PMID:23862004

  17. [Spatio-Temporal Bioelectrical Brain Activity Organization during Reading Syntagmatic and Paradigmatic Collocations by Students with Different Foreign Language Proficiency].

    PubMed

    Sokolova, L V; Cherkasova, A S

    2015-01-01

    Texts or words/pseudowords are often used as stimuli for human verbal activity research. Our study pays attention to decoding processes of grammatical constructions consisted of two-three words--collocations. Russian and English collocation sets without any narrative were presented to Russian-speaking students with different English language skill. Stimulus material had two types of collocations: paradigmatic and syntagmatic. 30 students (average age--20.4 ± 0.22) took part in the study, they were divided into two equal groups depending on their English language skill (linguists/nonlinguists). During reading brain bioelectrical activity of cortex has been registered from 12 electrodes in alfa-, beta-, theta-bands. Coherent function reflecting cooperation of different cortical areas during reading collocations has been analyzed. Increase of interhemispheric and diagonal connections while reading collocations in different languages in the group of students with low knowledge of foreign language testifies of importance of functional cooperation between the hemispheres. It has been found out that brain bioelectrical activity of students with good foreign language knowledge during reading of all collocation types in Russian and English is characterized by economization of nervous substrate resources compared to nonlinguists. Selective activation of certain cortical areas has also been observed (depending on the grammatical construction type) in nonlinguists group that is probably related to special decoding system which processes presented stimuli. Reading Russian paradigmatic constructions by nonlinguists entailed increase between left cortical areas, reading of English syntagmatic collocations--between right ones.

  18. ELECTRIC IMPEDANCE OF NITELLA DURING ACTIVITY

    PubMed Central

    Cole, Kenneth S.; Curtis, Howard J.

    1938-01-01

    The changes in the alternating current impedance which occur during activity of cells of the fresh water plant Nitella have been measured with the current flow normal to the cell axis, at eight frequencies from 0.05 to 20 kilocycles per second, and with simultaneous records of the action potential under the impedance electrodes. At each frequency the resting cell was balanced in a Wheatstone bridge with a cathode ray oscillograph, and after electrical stimulation at one end of the cell, the changes in the complex impedance were determined from the bridge unbalance recorded by motion pictures of the oscillograph figure. An extension of the previous technique of interpretation of the transverse impedance shows that the normal membrane capacity of 0.9 µf./cm.2 decreases about 15 per cent without change of phase angle, while the membrane resistance decreases from 105 ohm cm.2 to about 500 ohm cm.2 during the passage of the excitation wave. This membrane change occurs during the latter part of the rising phase of the action potential, and it is shown that the membrane electromotive force remains unchanged until nearly the same time. The part of the action potential preceding these membrane changes is probably a passive fall of potential ahead of a partial short circuit. PMID:19873091

  19. Chronic abdominal wall pain--a diagnostic challenge for the surgeon.

    PubMed

    Lindsetmo, Rolv-Ole; Stulberg, Jonah

    2009-07-01

    Chronic abdominal wall pain (CAWP) occurs in about 30% of all patients presenting with chronic abdominal pain. The authors review the literature identified in a PubMed search regarding the abdominal wall as the origin of chronic abdominal pain. CAWP is frequently misinterpreted as visceral or functional abdominal pain. Misdiagnosis often leads to a variety of investigational procedures and even abdominal operations with negative results. With a simple clinical test (Carnett's test), >90% of patients with CAWP can be recognized, without risk for missing intra-abdominal pathology. The condition can be confirmed when the injection of local anesthetics in the trigger point(s) relieves the pain. A fasciotomy in the anterior abdominal rectus muscle sheath through the nerve foramina of the affected branch of one of the anterior intercostal nerves heals the pain.

  20. [Prognostic value of chosen parameters of mechanical and bioelectrical uterine activity in prediction of threatening preterm labour].

    PubMed

    Zietek, Jerzy; Sikora, Jerzy; Horoba, Krzysztof; Matonia, Adam; Jezewski, Janusz; Magnucki, Jacek; Kobielska, Lucyna

    2009-03-01

    To record and analyse bioelectrical activity of the uterine muscle in the course of physiological pregnancy, labour and threatening premature labour; to define which parameters from the analysis of both electrohysterogram and mechanical activity signal allow us to predict threatening premature labour. Material comprised 62 pregnant women: Group I--27 patients in their first physiological pregnancy, Group II--21 patients in their first pregnancy with symptoms of threatening premature labour, and Group III--14 patients in the first labour period. The on-line analysis of the mechanical (TOCO) and electrical (EHG) contraction activity relied on determination of quantitative parameters of detected uterine contractions. The obtained statistical results demonstrated a possibility to differentiate between Group I and II through the amplitude and contraction area for EHG signal, and only the contraction amplitude for TOCO signal. Additionally, significant differentiating parameters for electrohysterogram are: contraction power and its median frequency. Analyzing Group I and III, significant differences were noted for contraction amplitude and area obtained both from EHG and TOCO signals. Similarly, the contraction power (from EHG) enables us to assign the contractions either to records from Group I or to labour type. There was no significant difference noted between Group II and III. Identification of pregnant women at risk of premature labour should lead to their inclusion in rigorous perinatal surveillance. This requires novel, more sensitive methods that are able to detect early symptoms of the uterine contraction activity increase. Electrohysterography provides complete information on principles of bioelectrical uterine activity. Quantitative parameters of EHG analysis enable the detection of records (contractions) with the symptoms of premature uterine contraction activity.