scholarly journals DC feedback for wide band frequency fixed current source

2019 ◽  
Vol 4 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Aoday H. Al-Rawi ◽  
W. M. A. Ibrahim ◽  
Eraj Humayun Mirza
Keyword(s):  
High Speed ◽  
Current Source ◽  
Bioelectrical Impedance ◽  
Wide Band ◽  
Impedance Analysis ◽  
Input Voltage ◽  
Blood Analysis ◽  
Composition Analysis ◽  
Current Feedback ◽  
Band Frequency

Abstract Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100 kHz bioelectrical impedance devices are commonly used for body composition analysis. High frequency bioelectrical impedance analysis devices are mostly used in bioimpedance tomography and blood analysis. High speed op-amps and voltage comparators are used in this circuit. Direct current feedback is used to prevent delay. An N-Channel J-FET transistor was used to establish the voltage controlled gain amplifier (VCG). A sine wave signal has been applied as input voltage. The value of this signal should be constant in 170 mV rms to keep the output current in about 1 mA rms. Four frequencies; 100 kHz, 1 MHz, 2 MHz and 3.2 MHz were applied to the circuit and the current was measured for different load resistances. The results showed that the current was stable for changes in the resistor load, bouncing around an average point as a result of bouncing DC feedback.

Techniques For Assessment Of Body Composition In Health

2018 ◽  
Author(s):  
Carla M Prado ◽  
Camila LP Oliveira ◽  
M Cristina Gonzalez ◽  
Steven B Heymsfield
Keyword(s):  
Body Composition ◽  
Nutritional Status ◽  
Bioelectrical Impedance Analysis ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Dual Energy ◽  
Composition Analysis ◽  
Body Composition Assessment ◽  
Air Displacement Plethysmography ◽  
X Ray

Body composition assessment is an important tool in both clinical and research settings able to characterize the nutritional status of individuals in various physiologic and pathologic conditions. Health care professionals can use the information acquired by body composition analysis for the prevention and treatment of diseases, ultimately improving health status. Here we describe commonly used techniques to assess body composition in healthy individuals, including dual-energy x-ray absorptiometry, bioelectrical impedance analysis, air displacement plethysmography, and ultrasonography. Understanding the key underlying concept(s) of each assessment method, as well as its advantages and limitations, facilitates selection of the method of choice and the method of the compartment of interest. This review contains 5 figures, 3 tables and 52 references Key words: air displacement plethysmography, bioelectrical impedance analysis, body composition, disease, dual-energy x-ray absorptiometry, health, muscle mass, nutritional status, obesity, sarcopenia, ultrasound fat mass

scholarly journals Ichthyometry and electrical bioimpedance analysis to estimate the body composition of tambatinga

2014 ◽  
Vol 44 (2) ◽  
pp. 279-286 ◽  
Author(s):  
Francisco Teixeira Andrade ◽  
Márvio Lobão Teixeira de Abreu ◽  
João Batista Lopes ◽  
Agustinho Valente de Figueiredo ◽  
Maria de Nazaré Bona Alencar Araripe ◽  
...  
Keyword(s):  
Body Composition ◽  
Water Content ◽  
Correlation Coefficients ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
The Body ◽  
Composition Analysis ◽  
Average Weight ◽  
Electrical Bioimpedance ◽  
The Relationship

Body composition analysis is relevant to characterize the nutritional requirements and finishing phase of fish. The aim of this study was to investigate the relationship between ichthyometric (weight, total and standard length, density and yields), bromatological (fat, protein, ash and water content) and bioelectrical-impedance-analysis (BIA) (resistance, reactance, phase angle and composition indexes) variables in the hybrid tambatinga (Colossoma macropomum × Piaractus brachypomus). In a non-fertilized vivarium, 520 juveniles were housed and fed commercial rations. Then, 136 days after hatching (DAH), 15 fish with an average weight of 37.69 g and average total length of 12.96 cm were randomly chosen, anesthetized (eugenol) and subjected to the first of fourteen fortnightly assessments (BIA and biometry). After euthanasia, the following parts were weighed: whole carcass with the head, fillet, and skin (WC); fillet with skin (FS); and the remainder of the carcass with the head (CH). Together, FS and CH were ground and homogenized for the bromatological analyses. Estimates of the body composition and yields of tambatinga, with models including ichthyometric and BIA variables, showed correlation coefficients ranging from 0.81 (for the FS yield) to 1,00 (for the total ash). Similarly, models that included only BIA variables had correlation coefficients ranging from 0.81 (FS and CH yields) to 0.98 (for the total ash). Therefore, in tambatinga, the BIA technique allows the estimation of the yield of the fillet with skin and the body composition (water content, fat, ash, and protein). The best models combine ichthyometric and BIA variables.

scholarly journals Body Composition Analysis by Using Bioelectrical Impedance in a Young Healthy Chinese Population: Methodological Considerations

2017 ◽  
Vol 38 (2) ◽  
pp. 172-181 ◽  
Author(s):  
Wei Chen ◽  
Hua Jiang ◽  
Jiong-xian Yang ◽  
Hao Yang ◽  
Jing-min Liu ◽  
...  
Keyword(s):  
Body Composition ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Data Matrix ◽  
Composition Analysis ◽  
Chinese Populations ◽  
Protein Mass ◽  
Reference Methods ◽  
Healthy Chinese ◽  
Methodological Considerations

Objective: To develop a new bioelectrical impedance analysis (BIA) model for analyzing body composition by using isotope dilution, magnetic resonance imaging (MRI), and dual-energy X-ray absorptiometry (DEXA) as the reference methods in young healthy Chinese populations. Methods: Thirty healthy participants were enrolled. Their body composition was analyzed using BIA and 3 reference methods. We established a model that uniformed data from 3 references methods (isotope, MRI, and DEXA) into 1 formula. This model was further validated with 209 participants. Results: The following BIA body composition adjustment model was developed: [Formula: see text], where X represents the impedance index; when K = 1, 2, and 3, Y represents total body water, fat mass, and bone mass, respectively. The prediction accuracy of this formula was 93.3%. By incorporating the data matrix, the protein mass was calculated using BIA: [Formula: see text]. In the verification part of this study, the lean body mass measured using DEXA and BIA was 43.02 ± 8.34 kg and 45.85 ± 8.81 kg, respectively. Analysis indicated that the model fit was extremely favorable ( R2 = .9997, P < .001). Conclusions: The accuracy of BIA measurement on body composition and protein mass is significantly improved by our work.

scholarly journals Bioelectrical Impedance Analysis of Body Composition in Karate Athletes Regarding The Preparatory Period // Analiza telesnog sastava karatista bioelektričnom impedansom pre i posle pripremnog perioda

2017 ◽  
Vol 12 (2) ◽  
Author(s):  
Jasmina Pluncević Gligoroska ◽  
Sanja Mančevska ◽  
Niki Matveeva ◽  
Elizabeta Sivevska ◽  
Žarko Kostovski
Keyword(s):  
Body Composition ◽  
Body Fat ◽  
Bioelectrical Impedance Analysis ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Body Fluids ◽  
Composition Analysis ◽  
Preparatory Period ◽  
Body Components ◽  
Karate Athletes

The aim of the paper was to asses changes in body composition using bioelectrical impedance analysis (BIA) methodology in members of national karate team after teen week preparatory training period. The investigation was carried out on 11 male karate contestants, aged 18 to 28 years mean age (21.82± 3.58). The body composition was analyzed with In Body 720. The BIA outcomes were divided in 3 group of variables: body fluid and body composition variables, obesity diagnose variables and segmental analysis variables. All BIA variables were insignificantly higher at second measuring (p>005). Only Body mass index (BMI=24.1 vs 24.55); mineral (4.69 kg vs 4.77 kg) and osseous (3.85 kg vs 3.92 kg), were significantly higher (p≤0.05) after preparatory period. Body fat mass (BFM=10.34 kg vs 10.75 kg, p=0.329) and body fat percent (BF%= 12.73 vs13.22%) insignificantly increased after preparatory period. The skeletal mass has changed from 40.03kg to 40.55kg (p=0.276). Body composition analysis, changes in weight, BMI and body fluids are essential for weight categories dependent sports such as karate. Positive changes in body components and in body fluids suggest that the training process during the preparatory period did not show negative effects on body components and the hydration of the karate athletes.

Comparison of three techniques for body composition analysis in cystic fibrosis

1993 ◽  
Vol 75 (1) ◽  
pp. 162-166 ◽  
Author(s):  
L. C. Lands ◽  
C. Gordon ◽  
O. Bar-Or ◽  
C. J. Blimkie ◽  
R. M. Hanning ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Body Composition ◽  
Nutritional Assessment ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Composition Analysis ◽  
Dual Photon Absorptiometry ◽  
Regression Equations ◽  
Body Composition Analysis ◽  
And Control

Body composition analysis is an important component of nutritional assessment in cystic fibrosis (CF). No gold standard of measurement exists, and techniques applicable to healthy populations may be unsuitable for CF patients. We assessed lean body mass (LBM) in 12 children with CF by skinfold (SK) measurements, bioelectrical impedance analysis (BIA), and dual-photon absorptiometry (DPA) and repeated these measures in 10 subjects 6 mo later. SK and DPA measures in eight older CF patients and eight healthy controls were compared to evaluate any effect of disease on estimates of LBM by use of DPA. Good agreement between the measures was seen at baseline and 6 mo by use of concordance plots. However, the limits of agreement between measures ranged up to 19% of SK-derived LBM measures (baseline: SK and DPA, 2.63 to -3.93 kg; SK and BIA, 2.36 to -1.24 kg; BIA and DPA, 1.88 to -4.28 kg; 6 mo: SK and DPA, 2.10 to -3.58 kg; SK and BIA, 6.28 to -5.49 kg; BIA and DPA, 5.53 to -7.79 kg). The change in LBM over 6 mo did not correlate among the three measures. Only BIA change in LBM correlated with weight change (r = 0.716, P < 0.02), probably due to the inclusion of weight in the regression equations for determining LBM from impedance. The relationship between SK and DPA measures did not differ between the CF and control groups, suggesting that there was no effect of disease on the DPA measure. The results suggest that none of these methods is precise enough to follow short-term changes in the nutritional status of CF patients longitudinally.

COMPARISON OF NEAR-INFRARED SPECTROSCOPY AND BIOELECTRICAL IMPEDANCE ANALYSIS FOR THE ASSESSMENT OF BODY COMPOSITION IN THE FRAIL ELDERLY

2014 ◽  
pp. 1-5
Author(s):  
T. KAMO ◽  
H. ISHII ◽  
D. TAKAHASHI ◽  
K. IWAGAYA ◽  
T. ISHIDA ◽  
...  
Keyword(s):  
Body Composition ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Frail Elderly ◽  
Bioelectrical Impedance Analysis ◽  
Near Infrared ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Community Dwelling ◽  
Composition Analysis

Background: Body composition is an important component of health related fitness. Near-infrared spectroscopy (NIRS) is a non-invasive, simple and rapid method of assessing body fat percentage. However, it is unknown whether NIRS can accurately estimate FFM in community-dwelling frail elderly. Objectives: This study aimed to compare NIRS with bioelectrical impedance analysis (BIA) in FFM measurement. Design: Cross-sectional study. Setting: Shizuoka, Japan. Participants: The study population comprised 53 community-dwelling frail elderly (15 men, 38 women; mean age 84.8±6.4 years; body mass index 19.7±3.5 kg/m2). Measurement: FFM and percentage fat mass (%FM) were estimated using a NIRS device at two sites (biceps and calf) and compared to body composition measured by BIA. Simple linear regression and Bland–Altman analyses were used to determine agreement between the methods. Results: FFM determined by BIA highly correlated with that determined by NIRS at both the biceps and calf (r=0.92 for both; p<0.001). The correlation coefficients for %FM estimated by NIRS were slightly lower (r=0.70 for biceps; r=0.66 for calf). In NIRS assessments, systematic biases were found for %FM but not for FFM. Conclusion: NIRS has significant potential for body composition analysis. Further comparative and longitudinal studies need to be conducted using an agreed reference analysis method to find a simple and more suitable method that can be applied among the community-dwelling frail elderly.

Nonlethal estimation of proximate composition in fish

2005 ◽  
Vol 62 (2) ◽  
pp. 269-275 ◽  
Author(s):  
M Keith Cox ◽  
Kyle J Hartman
Keyword(s):  
Body Composition ◽  
Brook Trout ◽  
Bioelectrical Impedance Analysis ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Composition Analysis ◽  
Common Denominator ◽  
Spatial And Temporal Scales ◽  
Warmwater Fish ◽  
Group Relationships

The need to precisely measure growth is a common denominator in many fisheries studies, but growth measures other than total masses or lengths are nearly nonexistent because more precise measurements such as body composition analysis are often too difficult and time consuming. Here, we present a means of estimating body composition in fish quickly, and after validation, without the need to sacrifice the animal. Models built with brook trout (Salvelinus fontinalis) were linear with strong validation group relationships (R2 > 0.96) for composition parameters including water, protein, fat, fat-free, and dry masses. Subject responses to bioelectrical impedance analysis were minimal, with only slight bruising (p < 0.001) with no effect on swimming, color, bleeding, or feeding. The model was also tested on the water and dry masses of 10 warmwater fish species and found to have strong correlations (R2 > 0.86), suggesting that more general relationships may exist. Nonlethal estimation of body composition using bioelectrical impedance analysis will permit increased precision in bioenergetics energy flow and compositional studies as well as permit study of community energetics and condition on spatial and temporal scales not previously possible.

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