scholarly journals Circuit Models of Bioelectric Impedance

2020 ◽  
Author(s):  
Alexandru Gabriel Gheorghe ◽  
Florin Constantinescu ◽  
Miruna Nițescu ◽  
Mihai Eugen Marin
Keyword(s):  
Impedance Analysis ◽  
The Body ◽  
Fluid Distribution ◽  
Accurate Information ◽  
Frequency Range ◽  
Body Impedance ◽  
Water Volumes ◽  
Artery Disease ◽  
Rc Circuit ◽  
Cole Model

Accurate information about fluid distribution in different compartments of the human body is very important in various areas of medicine like drug dosage, renal replacement therapy, nutritional support, coronary artery disease, colorectal cancer and HIV infection. The body impedance analysis method being simple, inexpensive, accurate and noninvasive is largely used to this end. Several models of the body impedance are presented in this chapter. The first is the Cole model, a linear, first-order RC circuit valid for a frequency range of two decades. Another model, developed by De Lorenzo, employs a fractional-order impedance whose parameters are identified using the frequency characteristics of the impedance module and can be used for a frequency range of three decades. In addition, two other models are presented, a ladder RC model valid for a frequency range of two decades and its extension to three decades, as well as a circuit containing multiple RC branches connected in parallel. These two models are obtained by approximating the measured body admittance modulus with a physically realizable circuit function followed by the circuit synthesis. The last model can be simplified, its simplest form being the Cole model. Allowing a better prediction of the intracellular and extracellular water volumes, this model can be viewed as an extension of the Cole model.

scholarly journals Complex assessment of athletes’ operative status and its correction during competitions, based on the body impedance analysis

2021 ◽  
Vol 25 (2) ◽  
pp. 66-73
Author(s):  
Olena Dorofieieva ◽  
Kseniia Yarymbash ◽  
Iryna Skrypchenko ◽  
Marko Joksimović ◽  
Aneliia Mytsak
Keyword(s):  
Confidence Interval ◽  
Impedance Analysis ◽  
Component Composition ◽  
The Body ◽  
Fat Free Mass ◽  
Multiple Regression Equation ◽  
Total Load ◽  
Functional Diagnosis ◽  
Highly Skilled ◽  
Body Impedance

Background and Study Aim. The aim of this research was assessment and correction of highly skilled swimmers’ operative status during competitions. Material and Methods. The authors carried out complex assessment of 46 high-skilled swimmers during competition period. The body impedance analysis and functional status express diagnosis were conducted before and after competitions. Results. The components limiting the operational state of swimmers were determined: “component composition of the body” (44.83% of the total load), “functional” (19.97%).  Correlation relationships were established between the main indicators that determine the level of the operational state of athletes.  The multiple regression equation was calculated, which made it possible to determine the influence of individual significant parameters on the level of the operational state of athletes and the confidence interval.  A group of athletes with operational status indicators below the confidence interval received sport supplementation. Conclusion. The main characteristics of the athletes’ operative status are cellular biomarker phase, fat free mass, extracellular water, intracellular water, strength index. These characteristics should be used in assessment of both operative status and complex functional diagnosis of highly-skilled swimmers during competitions.

Truth revealed: Challenging the mythical narrative of the low-profit limited liability company

2021 ◽  
Author(s):  
Sonia J. Toson
Keyword(s):  
Critical Analysis ◽  
Social Enterprise ◽  
Limited Liability ◽  
The Body ◽  
Business Community ◽  
Accurate Information ◽  
Limited Liability Company ◽  
Social Entrepreneurs ◽  
Form Analysis ◽  
Community Interest

This article reviews the body of literature concerning low-profit limited liability companies and conducts a critical analysis of the “flaws” frequently cited in the literature as problematic within the form. Analysis of the low-profit limited liability company (L3C) is conducted in the larger, global context of social enterprise, with emphasis on the social purpose company of Belgium and the community interest company of the United Kingdom as points of comparison. Findings demonstrate that the most commonly stated criticisms of L3Cs are in fact inaccurate. A deeper critical analysis of the form reveals that this choice of entity is advantageous on several levels for both social entrepreneurs and private charitable foundations. This piece furthers the literature by dispelling the myths surrounding L3Cs, providing counterarguments to the existing criticisms of the form and providing the business community with accurate information regarding the benefits of L3Cs for social enterprise.

scholarly journals Comparative Study On Concentration Of Some Minerals Found In Garlic (Allium Sativum Linn ) Species Grown In Some African Countries

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Sa’adatu M. E. ◽  
Mshelia M. S.
Keyword(s):  
Blood Clotting ◽  
Allium Sativum ◽  
Manganese Content ◽  
The Body ◽  
Fluid Distribution ◽  
African Countries ◽  
Nervous Excitability ◽  
Teeth Development ◽  
Potassium Magnesium ◽  
Reasonable Variation

The concentrations of some minerals: K, Ca, P, Mg, Mn and Cu found in garlic species grown in Nigeria, Senegal and Chad were determined using Atomic Absorption Spectroscopy. The results showed that Nigerian garlic specie contained the highest concentration of phosphorus (1.29mg/L) and Copper (0.017mg/L). Calcium was found to be highest in Senegalese garlic specie (8.639 mg/L) with the Nigerian specie having the second-highest recorded value (6.930 mg/L). The highest values of Potassium, Magnesium and Manganese content were recorded for Chadian garlic (68.26mg/L), (51.60mg/L) and (0.212mg/L) respectively. The results obtained show that Senegalese garlic is rich in Calcium which is an essential mineral required for bone and teeth development, and also in the regulation of nervous excitability. Nigerian garlic is rich in Phosphorus which is a key component of the nucleic acids and also takes part in bone and teeth development; and Copper which plays an important part in blood clotting. The garlic specie from Chad is rich in Potassium, Magnesium and Manganese. Potassium plays an important role in maintaining pH balance and fluid distribution in the body; Magnesium in proper functioning of the muscles; Manganese is used in proper bone formation. Also from the results, there is reasonable variation in the concentration of the minerals, and this may be attributed to the types of soils on which the different garlic species were grown.

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 Eating Habits and Body Composition of International Elite Soccer Referees

2020 ◽  
Vol 71 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Gabriele Mascherini ◽  
Cristian Petri ◽  
Elena Ermini ◽  
Angelo Pizzi ◽  
Antonio Ventura ◽  
...  
Keyword(s):  
Body Composition ◽  
Eating Habits ◽  
Impedance Analysis ◽  
Skinfold Thickness ◽  
Normal Weight ◽  
The Body ◽  
Body Composition Assessment ◽  
Dietary Recall ◽  
Low Level ◽  
Vitamin B9

AbstractSoccer referees are a specific group of the athletes’ population whose careers peak from 30 to 45 years old. An athlete's performance is not only determined by physical training but also by a lifestyle, e.g. eating habits. The purpose of this study was to verify current eating habits and resulting body composition of a group of elite international soccer referees. At an international FIFA seminar 60 elite international soccer referees (aged 39.2 ± 4.2 years) were enrolled. A body composition assessment was performed with skinfold thickness and bio impedance analysis, while eating habits were evaluated with a multi-pass 24-hour dietary recall. The body composition showed a normal weight condition with a fat content of 11.4 ± 2.5%. Macronutrients showed a low level of carbohydrates (43.6 ± 5.4%) and a high level of fat (40.0 ± 4.5%). Micronutrients showed a low level of calcium, potassium, zinc, magnesium, iodine, vitamin B12 and vitamin B9. Even though their body composition was within the normal range, the current eating habits of elite international soccer referees did not appear to follow the nutrition guidelines. Therefore, it would be advisable to provide knowledge on nutrition for this particular category of sports subjects, an individualized nutritional plan would be advisable, in order to achieve and maintain better performance and appropriate body composition for their role.

scholarly journals Bandwidth and Common Mode Optimization for Current and Voltage Sources in Bioimpedance Spectroscopy

2021 ◽  
Vol 12 (1) ◽  
pp. 135-146
Author(s):  
Tobias Menden ◽  
Jascha Matuszczyk ◽  
Steffen Leonhardt ◽  
Marian Walter
Keyword(s):  
Patient Safety ◽  
Current Source ◽  
The Body ◽  
Voltage Source ◽  
Bioimpedance Spectroscopy ◽  
Laboratory Measurements ◽  
Output Impedance ◽  
Frequency Range ◽  
Common Mode ◽  
High Bandwidth

Abstract Bioimpedance measurements use current or voltage sources to inject an excitation signal into the body. These sources require a high bandwidth, typically from 1 kHz to 1 MHz. Besides a low common mode, current limitation is necessary for patient safety. In this paper, we compare a symmetric enhanced Howland current source (EHCS) and a symmetric voltage source (VS) based on a non-inverting amplifier between 1 kHz and 1 MHz. A common mode reduction circuit has been implemented in both sources. The bandwidth of each source was optimized in simulations and achieved a stable output impedance over the whole frequency range. In laboratory measurements, the output impedance of the EHCS had its -3 dB point at 400 kHz. In contrast, the VS reached the +3 dB point at 600 kHz. On average over the observed frequency range, the active common mode compensation achieved a common mode rejection of -57.7 dB and -71.8 dB for the EHCS and VS, respectively. Our modifications to classical EHCS and VS circuits achieved a low common mode signal between 1 kHz and 1 MHz without the addition of complex circuitry, like general impedance converters. As a conclusion we found VSs to be superior to EHCSs for bioimpedance spectroscopy due to the higher bandwidth performance. However, this only applies if the injected current of the VS can be measured.

scholarly journals Ultrasound assessment of muscle mass in the diagnosis of sarcopenia in cardiovascular patients

2021 ◽  
Vol 20 (3) ◽  
pp. 2699
Author(s):  
A. S. Erokhina ◽  
E. D. Golovanova ◽  
M. A. Miloserdov
Keyword(s):  
Body Mass Index ◽  
Muscle Mass ◽  
Body Mass ◽  
Lower Leg ◽  
The Body ◽  
Russian Society ◽  
Speed Test ◽  
European Working ◽  
Class 1 ◽  
Artery Disease

Aim. To study the advantages of ultrasound versus anthropometric assessment of muscle mass for early diagnosis of sarcopenia in patients >45 years of age.Material and methods. The study included 79 patients aged 4589 years with coronary artery disease (CAD), hypertension, type 2 diabetes, heart failure, class 1-3 obesity. Diagnosis of hypertension was carried out according to the European (2018) and Russian (2019) guidelines; CAD — according to Russian Society of Cardiology (2020) guidelines. Sarcopenia was diagnosed according to 2010 European Working Group on Sarcopenia in Older People (EWGSOP) criteria and 2018 EWGSOP2 guidelines. Muscle mass (MM) was determined by two methods: 1 — by measuring the rectus abdominis muscle (RAM) thickness using the ultrasound; 2 — by measuring the arm and lower leg circumference. Muscle strength was determined by wrist dynamometer. Muscle function was assessed using the 4-m gait speed test.Results. The study showed that in patients aged >45 years admitted to the emergency cardiology department, the body mass index exceeded 25 kg/m2 in 88,6% of cases. The incidence of sarcopenia of varying severity was 55,7% (n=44). The differences in RAM thickness, arm and lower leg circumference between the groups of patients with/without sarcopenia were significant (p<0,001), but were less than the threshold only for RAM thickness. RAM thickness levels progressively decreased with increasing severity of sarcopenia and significantly differed at all stages compared to patients without sarcopenia (p<0,001), regardless of body mass index. A decrease in lower leg circumference below the threshold values determining a MM decrease was observed only in severe sarcopenia, and arm circumference — in both men and women only in severe sarcopenia. There were no significant differences for arm and lower leg circumference depending on sarcopenia stages in overweight and obese patients.Conclusion. MM assessment by measuring RAM thickness with ultrasound in comparison with the anthropometric method makes it possible to diagnose sarcopenia in patients >45 years of age with cardiovascular diseases and obesity at earlier stages and to promptly recommend preventive measures.

Bioelectrical impedance analysis of the body composition of children and adolescents with sickle cell disease

2002 ◽  
Vol 140 (6) ◽  
pp. 681-687 ◽  
Author(s):  
Dorothy J. VanderJagt ◽  
Paul Harmatz ◽  
Ajovi B. Scott-Emuakpor ◽  
Elliot Vichinsky ◽  
Robert H. Glew
Keyword(s):  
Body Composition ◽  
Sickle Cell Disease ◽  
Children And Adolescents ◽  
Sickle Cell ◽  
Bioelectrical Impedance Analysis ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
The Body ◽  
Cell Disease

Reappraisal of Factors Disturbing the Relationship between Body Water Volumes and Total Body Electrical Resistance in Patients on Hemodialysis

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Schotman JM ◽  
◽  
Reichert LJM ◽  
de Boer H ◽  
van Borren MMGJ ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Body Position ◽  
Body Water ◽  
The Body ◽  
Current Evidence ◽  
Electrode Position ◽  
Fluid Redistribution ◽  
Interpretation Errors ◽  
Water Volumes ◽  
Total Body

Background: Measurements of Total Body Electrical Resistance (TBER) are used to improve fluid balance management in patients on Hemodialysis (HD). This approach is based on the inverse relation that exists between TBER and body water volumes. Interpretation errors may occur if TBER measurements are affected by factors that are not related to changes in body water. Aim of this paper was to provide an overview of the methodological artifacts commonly encountered in a clinical setting, and to strengthen current evidence of their disturbing effects by performing additional experiments. Methods: This study includes an analysis of available literature data, supplemented with additional experiments in healthy adults and patients. A cutoff of 2.7% was used to classify changes in TBER as significant within individual subjects. Results: Electrode position, electrode interference, differences of measurements performed at the right or left side of the body, presence of orthopedic prosthesis located in the limbs, fluid redistribution induced by longterm changes in body position, and electrolyte abnormalities were the main disturbing factors that can induce a significant change in TBER. Other factors either had no significant disturbing effect or could be easily avoided. Conclusion: TBER measurements require a high degree of standardization to minimize interpretation errors.

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