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•A new method called Bioimpedance formalism (BIF) are presented.•The new approach were applied to explore the health status of volunteers.•BIF allows the study of relaxation process ...at time and frequency domain.•Beta-parameters and relaxation time are robust indicators of health.
This manuscript describes a novel methodology for studying relaxation dynamics in tissues and cells using characteristic frequency of bioimpedance spectroscopy measurements. The Bioimpedance Formalism allows for the simultaneous study of bioelectrical parameters in the frequency and time domains, providing insight into possible relaxation processes occurring in the tissue or cell of interest. Results from the Cole-Cole analysis showed no multiple relaxation processes associated with heterogeneity, with a visible age group separation in males compared with females. The study of the relaxation dynamic in the time domain revealed that the β parameter can be used to analyse the charge carriers in tissues, cells, or cancer cells, potentially leading to new diagnostic and therapeutic approaches for cancer and other diseases. Overall, this approach presents a promising area of research for gaining insights into the electrical properties of tissues and cells using bioimpedance methods.
RELATIONSHIO BETWEEN SKIN TEMPERATURE AND BODY COMPOSITION WOMEN Silva, Rayanne Kethleen do Nascimento; Matias, Francilene Lira; Gonçalves, Alessandra Feitosa ...
Revista brasileira de fisioterapia (São Carlos (São Paulo, Brazil)),
April 2024, 2024-04-00, Volume:
28
Journal Article
Peer reviewed
Infrared Thermography (IT) is a tool for the investigation of physiological functions through changes in blood flow that are associated with the control of Skin Temperature (Tsk). Tsk depends on ...extrinsic factors, such as environmental temperature and humidity; and intrinsic factors, such as anthropometric characteristics, circadian rhythm, age and sex. Sex, menstrual cycle, use of exogenous hormones, subcutaneous fat, and metabolic rate can affect female Tsk. Although there are already studies that relate temperature to body fat percentage, there are few inconclusive studies that correlate body composition with skin temperature by specific area.
To correlate skin temperature and body composition by body segments of women in the physiological menstrual cycle, use of exogenous hormones, and menopause.
This is a prospective observational study, Participants were 45 volunteers equally allocated into three groups: Exogenous Hormone Group (EHG) 24.53±4.30 years, 58.59±8.46kg, 161.13±6.67cm Physiological Menstrual Cycle Group (PMCG) 26.33±4.83 years, 58.12±10.02kg, 161±5.53cm and Menopause Group (MG) 57.13±8.79 years, 68.76±15.82kg, 157±7.16cm. The EHG volunteers use combined oral contraceptives, while the others did not use any other type of medication or hormonal supplementation. To control the circadian rhythm and the phase of the menstrual cycle, all of them underwent segmental body composition measurements (muscle mass and fat in kilograms) using an InBody 120 bioimpedance scale, and skin temperature measurements were made using a FLIR model T-360 camera once a week, at the same time, over a 28-day period. The areas of interest were the breast region, abdomen, trunk, lumbar spine, breech, upper and lower limbs. For correlation analysis between skin temperature and body composition a Pearson correlation test was performed using SPSS, version 21.
There was no significant correlation (P>0.05) between muscle mass and skin temperature of the evaluated areas in any of the groups or evaluation times. Regarding to body fatness, it was observed that independently of the phase from the menstrual cycle, the PMCG presented a negative correlation between temperature and trunk fatness (r= -0,780, P<0,01) and between upper limbs fatness and breast temperature (r= -0,655, P<0,01) and abdomen (r= -0,638, P<0,01).The EHG group showed significant negative correlations between body fat and temperature of breast (r=-0,712, P<0,01), abdomen (r= -0,701, P<0,01), posterior trunk (scapulae region) (r=-0,680, P<0,01), right lower limb (r= -0,672, P<0,01) and upper limbs (r=-0,686, P<0,01). The MG showed only negative correlation (r=-0,591, P<0,01) between fat and skin temperature of the posterior trunk.
Skin temperature has an inverse relationship with fatness of the assessed region, while resting muscle mass has little impact on the distribution of skin temperature in women at different stages of life.
The study shows the need to consider anthropometric characteristics when analyzing skin temperature by IT.
IntroductionThe methods for diagnosing compartment syndrome non-invasively remain under debate. Bioimpedance measurements offer a promising avenue in clinical practice, detecting subtle changes in ...organ impedance due to volume shifts. This study explores bioimpedance measurement as a novel, painless method for diagnosing compartment syndrome, potentially enabling continuous monitoring.ObjectiveThis work aims to develop a prototype device for non-invasive diagnosis of compartment syndrome based on bioimpedance changes and assess initial results through in vitro experiments on inanimate biological material. We assume a change in the bioimpedance value after the application of physiological solution.Materials and MethodsBetween 2018 and 2022, a prototype device for diagnosing limb compartment syndrome was collaboratively developed with the Department of Cybernetics and Biomedical Engineering at the Technical University of Ostrava, Czech Republic. This device operates by comparing bioimpedance between two compartments, one of which is pathologically affected (experiencing compartment syndrome). The Bioimpedance Analyzer for Compartment Syndrome (BACS) has been utilized to conduct measurements on inanimate biological material in laboratory settings. Two samples of duck and chicken tissue, as well as piglets, were employed for these experiments. According to the size of sample was compartment syndrome simulated by injecting 20–120 mL saline into one limb (breast) while leaving the other as a control. Invasive intramuscular pressure measurements were conducted post-saline injection using a conventional device (Stryker). Changes in bioimpedance were evaluated following saline application.ResultsThe non-invasive bioimpedance measurement instrument has been developed. It meets the safety requirements of European standard EN 60601-1. Measurement of accuracy showed minimal deviation for both channels (1.08% for the left channel and 1.84% for the right channel) when measuring on resistors. Ten measurements were conducted using the BACS prototype - two on chicken legs, two on duck breasts, two on duck legs, and four on piglets. Compartment syndrome simulation was achieved for all 10 measurements (IMP variance 31–45 mmHg). Following saline application, a notable decrease in bioimpedance was observed in the compartment simulating compartment syndrome (decrease by 12–78 Ω).ConclusionNon-invasive methods could revolutionize limb compartment syndrome diagnosis, offering advantages such as non-invasiveness and continuous monitoring of compartment swelling.
Bioelectrical impedance analysis-derived phase angle (PhA) has been gaining attention in the clinical evaluation of nutritional status because it is thought to be a proxy of water distribution and ...body cell mass; it is also associated to muscle strength and is an effective predictor of different clinical outcomes. Since an association may be expected between PhA and sarcopenia (defined by low skeletal muscle mass and impaired muscle function), the aim of this systematic review was to evaluate: a) changes in PhA due to sarcopenia; b) prevalence of sarcopenia according to PhA values; c) derivation of phase angle cut-offs for detecting sarcopenia; d) sarcopenia and PhA as predictors of clinical outcomes.
A systematic research on electronic databases (PubMed, Embase, Scopus and Web of Science) from inception to January 31st, 2020 was performed according to PRISMA checklist. Using PICOS strategy, “P” corresponded to participants of any age, gender or ethnicity, “I” designated diagnosis of sarcopenia, “C” indicated subjects without sarcopenia, “O” corresponded to PhA, and “S” selected all study types. Methodological quality was assessed using the National Institute of Health (NIH) quality assessment tool.
Through the initial literature search and after removing duplicates and excluding papers by screening titles and abstracts, 79 potentially relevant studies were examined. Thirteen studies (7668 subjects) met the inclusion criteria. The overall risk of bias was low. Sarcopenia was associated with a significant lower PhA in seven studies out of eight, while five studies out of six reported a high prevalence of sarcopenia was in patients with low PhA. Different cut-off point values from 4.05 to 5.05° have been derived for the identification of sarcopenia. PhA and sarcopenia were independent predictors of survival in cancer patients and geriatric hospitalized patients.
Data from the selected papers demonstrate that PhA is decreased in sarcopenic subjects and the prevalence of sarcopenia is higher in subjects with low PhA. Further studies are needed to determine to what extent PhA may be valuable in detecting low muscle quality and/or identifying sarcopenia.
•Phase angle is decreased in sarcopenic subjects.•The prevalence of sarcopenia is higher in subjects with low phase angle.•Phase angle may help in detecting low muscle quality and identifying sarcopenia.•Different cut-off phase angle values have been derived for identifying sarcopenia.
Assessment of hydration status in children undergoing hemodialysis (HD) is crucial. This study aimed to identify the techniques that can be utilized to assess fluid overload in children with ...end-stage renal disease (ESRD) undergoing HD. The study included 9 patients aged >5 years and < 18 years who underwent 27 HD sessions and were followed up for ≥1 month. The median age of the patients was 16 years (IQR: 5-17.8 years) and the female/male ratio was 1.25:1. Symptoms of volume overload were clinically observed based on 5 (18.5%) of the 27 measurements. There was a significant positive linear correlation between fluid overload by weight and pre- and post-HD bioimpedance spectroscopy (BIS) measurements (OH) (r=0.95 P=0.000). There was a significant difference in median IVC diameter between pre-HD and after HD (P=0.029). The median pre-HD IVC collapsing index was 13.8% (IRQ: 4%-46%), versus 17.1% (IRQ: 4.5%-45%) after HD; the difference was significant (P=0.000). BIS is the most widely used body composition monitor for estimating fluid status in children undergoing HD. The present study investigated the sensitivity of markers of volume load in children on a routine HD program. The parameters that best indicate volume load are the differences between pre-HD and post-HD BIS measurements, physical examination findings, and heart rate measurements.
Background. In the modern world, much attention is paid to the early diagnosis and prevention of diseases of patients, which is associated with the need to develop and improve non-invasive, easily ...accessible and accurate biomedical devices in order to monitor the parameters of the functioning of the human body. Bioimpedance is a noninvasive technique that has a variety of applications. Biological tissue in contact with electrodes under the influence of alternating current exhibits complex impedance behavior, which requires the creation of accurate biophysical and electrical models. Materials and methods. In this paper, the models of interaction between electrode-tissue contacts are considered, and the factors influencing the result of impedance measurement are analyzed. Results. Based on the considered models of electrode-tissue contact interaction, a method for increasing the sensitivity of measurement and the accuracy of impedance measurement is proposed. Conclusions. The successful implementation of bioimpedance diagnostics depends on the basic biophysical and electrical model of the system, as well as the interaction of the electrode with the tissue. The methods of interaction between the electrode and the tissue studied in the work make it possible to increase the sensitivity, as well as to reduce the measurement errors.
Novel freezing solutions are constantly being developed to reduce quality loss in meat production chains. However, there is limited focus on identifying the sensitive analytical tools needed to ...directly validate product changes that result from potential improvements in freezing technology. To benchmark analytical tools relevant to meat research and production, we froze pork samples using traditional (−25 °C, −35 °C) and cryogenic freezing (−196 °C). Three classes of analyses were tested for their capacity to separate different freeze treatments: thaw loss testing, bioelectrical spectroscopy (nuclear magnetic resonance, microwave, bioimpedance) and low-temperature microscopy (cryo-SEM). A general effect of freeze treatment was detected with all bioelectrical methods. Yet, only cryo-SEM resolved quality differences between all freeze treatments, not only between cryogenic and traditional freezing. The detection sensitivity with cryo-SEM may be explained by testing meat directly in the frozen state without prior defrosting. We discuss advantages, shortcomings and cost factors in using analytical tools for quality monitoring in the meat sector.
•Frozen pork examined.•Cryo-SEM: −25 °C ≠ −35 °C.•BI, MW and NMR: -25 °C/−35 °C ≠ −196 °C.
The bioimpedence phase angle has been considered as a predictor for morbidity and mortality in different clinical situations, although reference values from a large healthy population are lacking. ...The aim of this meta-analysis is to estimate mean phase-angle values in healthy individuals.
This meta-analysis systematically searched MEDLINE, EMBASE, The Cochrane Controlled Trials Register, SCIELO, LILACS, CINAHL, Web of Science and gray literature for studies estimating mean phase angles. Quality of evidence was assessed for all studies and subgroup (males and females) meta-analysis stratified by age group according to literature (up to 2; 3–5; 6–12; 13–15; 16–18; 19–28; 29–38; 39–48; 49–58; 59–69; 70–80 and >80 years of age) were conducted using random-effects models.
A total of 46 studies including 249,844 subjects were selected for the present analysis. Males show a pooled estimate of the mean phase angle of 3.6 (95% CI: 3.0–4.1) for infants (0–2 y), increasing progressively to 7.3 (95% CI: 7.0–7.5) at the teenage phase (16–18 y), stabilizing during adult ages (18–38) and decreasing progressively with ongoing years with an estimate of 5.3 (95% CI: 4.5–6.0) for elderly above 80 years old. Similarly, females start from 3.7 (95% CI: 3.2–4.3) for infants (0–2 y), increasing progressively to 6.4 (95% CI: 6.1–6.8) at the teenage phase (16–18 y), stabilizing during adult ages (18–48) and decreasing progressively with ongoing years with an estimate of 5.4 (95% CI: 5.3–5.6) for elderly above 80 years old. Also, males have higher estimates than females for all age groups except for infants (0–2) and subjects older than 80 years old. Heterogeneity was high for all age groups.
In both sexes, phase-angle values have a similar pattern that start from infants, increase progressively up to the teenage phase, stabilize during adult ages, and then decrease progressively in older subjects and the elderly.
•Phase angle is a predictor of morbidity and mortality in different clinical situations. Nevertheless, reference values from a large healthy population data are lacking.•This study synthesizes data from 46 studies including 249,844 health individuals and provides estimates for mean phase angle for males and females stratified by age.•Phase-angle increases progressively from the first years of life until 18 years of age, then stabilizes from 19 until 48 years and progressively decreases with ongoing years.•This study provides references values that can contribute to the prediction of health status in clinical practice.
In an ageing society, the incidence of hard‐to‐heal wounds is rising. Chronic wound healing is a complex process, which requires specialised treatment. Clinical assessment of the wound is essential ...to establish care approaches but is usually based on visual evaluation and it remains challenging. Therefore, innovative quantitative methods for the assessment of chronic wounds are needed. We conducted a single‐centre observational study designed to assess the feasibility of a bioimpedance measurement method conducted with a multielectrode sensor array to monitor the wound healing process in patients with chronic wounds of venous, mixed venous–arterial and diabetic aetiology. In total, 104 measurements of bioimpedance were conducted in 18 ulcers during the study. Across all 7 patients analysed, the bioimpedance of the ulcers was consistently increasing as the wound surface was decreasing. The variables had significant (p < 0.001) and strong negative correlation (r = −0.86). We validated the feasibility of the bioimpedance measurement method for the monitoring of the wound healing process on the lower legs. It may be a promising quantitative method for monitoring the status of the wounds. However, long‐term measurements are needed to show the usability of the electrode dressing and bioimpedance measurement in the assessment of chronic wounds.
This year, 2021, marks the “coming of age” for JoEB with its indexing in PubMed Central. It is also a century since some of the earliest studies on tissue impedance. This editorial briefly reviews ...the time-line of research in the field to mark this occasion.
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