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Air displacement assessment

Air displacement assessment

Nationwide trends of pediatric Muscle building and Lycopene and aging z-score from in China: assesdment findings from Lycopene and aging mobile- and displacemsnt data. C FM in 5-year-olds. The ADP was used as a standard against which the MF BIA was compared. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Air displacement assessment -

If each test is performed correctly according to the recommended guidelines, it is as accurate as hydrostatic underwater weighing, but quicker and easier to perform.

It is available in some research laboratories, athletic, military, university and health and wellness settings throughout the world. It is normally employed in validation studies and used with other techniques to determine 4-component models.

Using ADP, body composition is predicted from known densities of soft tissue. The density of fat is 0. A commonly used equation which translates whole body density to percent body fat is the Siri equation:. There are different equations for different ethnicities and children.

An alternative equation for the prediction of body fat in a Caucasian population is Brozek. Schutte et al have derived equations based on black ethnic origins. Considerations relating to the use of air displacement plethysmography are summarised by population in Table 2. Refer to section: practical considerations for objective anthropometry.

A method specific instrument library is being developed for this section. In the meantime, please refer to the overall instrument library page by clicking here to open in a new page. Previously, obtaining reliable infant body composition data has been difficult, with available methods limited by inaccuracy, practicality, invasiveness, and safety.

The PEA POD has solved some of these issues by offering more accurate and precise measurements of infant up to 10kg body fat and fat-free mass quickly 2 mins , safely, and comfortably using its patented and proven air displacement plethysmography. However, the use of this technique for longitudinal assessment of body composition between 1 and 4 years of age might still be limited due to the practical constraints mentioned above.

About About the DAPA Measurement Toolkit What's New Other resources Toolkit Team Contact. Introduction Validity Reliability Error and bias Feasibility Data processing Statistical assessment of reliability and validity Harmonisation.

Introduction Subjective methods Objective methods Harmonisation Videos Dietary assessment decision matrix. Introduction Subjective methods Objective methods Harmonisation Videos Physical activity assessment decision matrix. Introduction Subjective methods Objective methods Anthropometric indices Harmonisation Videos Anthropometry decision matrix.

Anthropometry Domain. Air displacement plethysmography. What is assessed? How is the measurement conducted?

When is this method used? How are estimates of body composition derived? The process is divided into three steps: measurement of mass, volume and thoracic gas volume. Mass measurement Weight is measured using a very precise, integrated electronic scale. The measurement of body volume by BOD POD involves the following steps: A 2-point calibration process starting with the empty chamber to establish a baseline volume and then with a 50L calibration cylinder.

If the first two measurements are inconsistent a third measurement is performed. The body volume is then corrected for thoracic volume either measured, predicted [Crapo et al, ], or entered manually. Pre-test Guidelines Participants must not eat or engage in strenuous exercise for at least 2 hours before the scheduled appointment and should wear minimal, form fitting clothing and use a swimming cap to be worn during the test.

Strength and limitations. An overview of the characteristics of air displacement plethysmography is outlined in Table 1. Table 1 Characteristics of air displacement plethysmography. Characteristic Comment Consideration Comment Number of participants Small Relative cost Medium Participant burden Low Researcher burden of data collection Low Researcher burden of coding and data analysis Low Risk of reactivity bias No Risk of recall bias No Risk of social desirability bias No Risk of observer bias No Space required Medium Availability Medium Suitability for field use No Participant literacy required No Cognitively demanding No.

Table 2 Anthropometry by air displacement plethysmography in different populations. Population Comment Pregnancy Suitable Infancy and lactation Use of this technique for longitudinal assessment of body composition between 1 and 4 years of age might be limited due to practical constraints, as weight capacity for a PEA POD is 10Kg.

Toddlers and young children This technique may be impractical in young children as the protocol requires the participant to stay as still as possible; movements can invalidate the volume estimates.

Adolescents Suitable Adults Suitable Older Adults Suitable Ethnic groups Suitable Other Suitable. Further considerations. Compared to underwater weighing, the BOD POD does not require getting wet and is suitable for special populations such as infants, children, obese, elderly and disabled persons.

Residual lung volume measurements are not needed like underwater weighing. Hydration status can adversely affect calculation results. Translate this page into:.

How to cite this article: Singh RK, Guru CS, Rastogi J, Jaipurkar R, Sharma A, Apte VV. Test-retest reliability of air displacement plethysmography BOD POD in the adult healthy Indian male population.

Indian J Physiol Pharmacol ; Significant intraclass correlations were also observed for pairs with maximum and minimum differences.

Body weight has been considered over time as an indicator of good health. Although, when examined closely, it is the composition of this body weight that is most important. Body weight comprises the weight of body water, muscle, organs, bones and fat both essential and non-essential.

The underlying issue is the excessive fat that accumulates due to unhealthy eating and lifestyle habits. This excess fat leads to multiple health issues, which further lead to being overweight and eventually, obesity. Researchers and clinicians have shown that people of the same age, weight and height have different body shapes, body compositions, metabolic profiles and energy requirements.

Various techniques are available to safely and accurately estimate the body composition in humans from birth through senescence. These are divided across basic field methods such as anthropometry and measurement of body mass index BMI ; progressive field methods such as measurement of skinfold techniques, bioelectrical impedance and near-infrared interactome measurements and advanced laboratory and imaging techniques such as hydrostatic weighing, air displacement plethysmography ADP , MRI scans and DEXA scans.

ADP, the trade name for which BOD POD, is widely gaining more acceptances due to the ease and less time required to measure the body composition. BOD POD has shown excellent reliability, accuracy and precision in volume measurement. It is a non-invasive and quick technique that does not require the exhaustive technical training of technicians and is convenient for a wide variety of subjects from obese to elderly and for estimating percentage of fat in a large population.

The principle underlying ADP centres on the relationship between pressure and volume. At isothermal conditions, volume and pressure are inversely related. Once BV is calculated, body density BD can be calculated, and the percentages of fat and fat-free mass can be estimated by the Siri equation.

Measuring body composition by ADP is a safe and reliable method, which was first introduced in the year Due to high reliability and ease of conducting the assessment, patient compliance is better, and tracking changes in the body composition is possible at frequent intervals.

Hence, data to confirm the reliability of this technology in the Indian population is limited. Thus, the purpose of our study was to determine the test-retest reliability of body fat percentage by the BOD POD in healthy Indian men.

This cross-sectional study was conducted among the Indian population at a national-level sports training institute between October and July Written informed consent was obtained from all participants, and the test results were communicated to them.

Exclusion criteria were the following: history of smoking, chronic diseases such as hypertension, diabetes, hypothyroidism, obesity, endocrine disease, metabolic disease and recent hospitalisation due to any major injury or trauma.

The study was conducted at the high-performance laboratory at the National Sports Institute in Western India. Participants were instructed not to exercise and not to eat 3—4 h before each testing session; however, minimal water consumption was allowed. A tight-fitting acrylic swim cap was also worn before changing into the spandex shorts, and participants were asked to use the restroom to eliminate waste to minimise measurement error.

Before measurement of anthropometric parameters and fat percentage by BOD POD, all participants completed the International Physical Activity Questionnaire IPAQ to assess their daily physical activities over the past 7 days. Each participant underwent an anthropometric assessment performed by a Level 1 anthropometrist qualified by the International Society for the Advancement of Kinanthropometry ISAK , in accordance with the ISAK guidelines.

We measured the hip circumference HC at the maximum extension of the buttocks as viewed from the right side. Waist hip ratio WHR was calculated by dividing WC by HC. McCrory et al. found no difference between measured and predicted values of TGV in adults; thus, a predicted value was used for participants who could not able to perform satisfactorily the procedure after three attempts during the first trial.

The uncorrected BV was adjusted for TGV and used to determine the actual BV. Body fat was calculated using the Siri equation. All testing sessions were conducted by the same technician.

Before testing each day, the scale was calibrated using two kg weights, and volume calibration was automatically performed at the beginning of every test using an internal calibration cylinder connected to the test chamber with a controlled valve.

BOD POD is designed to automatically measure BV twice on each run, and if the software spots a difference of mL or greater in BV, it performs a third test on the participant. After the first measurement, each participant repeated the entire process, including the measurement of body weight and two-point calibration.

All repeated measures were performed immediately after the initial measurements and were completed by the same technician. All statistical analyses were performed using R Studio Version 1.

Descriptive statistics of key variables were expressed as mean, standard deviation, minimum and maximum range. Of these three observations, the pair with the smallest absolute difference was considered for test-retest reliability. Positive and negative differences may affect reliability; hence, the absolute difference was calculated.

The coefficient of variation CV for the repeated measures was calculated. Test-retest reliability was calculated using the intraclass correlation ICC.

In this study, 74 participants voluntarily participated in the study. Of the 74 participants, ten were sedentary, 23 had low activity levels, 36 were active and five were highly active in their daily routine based on activity level inferred from the IPAQ.

The mean age of the participants was The mean BMI was observed to be According to the WHO, the cutoff value for WHR was 0. ICC1: Test-retest reliability between trial 1 and trial 2 ICC2 test-retest reliability between trials with minimum differences, ICC3 test-retest reliability between trials with maximum difference, SEM: Standard error of measurement, TEM: Technical error of measurement.

Hence, ICC2 represents reliability for pairs with minimum difference, and ICC3 represents the reliability of pairs with a maximum difference. We observed that when pairs with a maximum difference were considered, the reliability index ICC3 for BV and BM did not change.

The CV for BM and BV was close to zero. This study aimed to test the test-retest reliability of BOD POD in a healthy Indian population to assess body composition. BOD POD is an attractive tool for measuring body composition in a variety of clinical, research and commercial settings due to its ease of use and excellent subject compliance.

At present, there is limited research regarding the reliability of BOD POD in the Indian population. Descriptive statistics of basic anthropometric characteristics of the participants suggests that the subjects of the present study were below the borderline, healthy and non-obese.

Overall, BOD POD reported good test-retest reliability. Noreen and Lemon observed ICC index of 0. Anderson reported a CV of 0.

These studies included men and women; hence, the variation observed may be on a higher side. The present study showed a significant reduction in BM between trials 1 and 2.

Noreen and Lemon reported similar results as BM. The present study observed a CV of 2. for three trials 2. Miyatake et al. reported a CV of 2. Noreen and Lemon reported a CV of 3. The ICC was 0. reported 0. Noreen and Lemon reported that the TEM was 1. reported a TEM of 0.

The present study included the Indian adult male population from various regions of India and showed that BOD POD appears to be a reliable measure for determining the body composition of this group of populations. Conducting multiple trials and subsequently comparing the two closest values have been shown to provide an excellent test-retest reliability index for BOD POD.

A small but significant decrease in BM was observed with repeated measures, which was also found to not influence the reliability of the body composition measurements.

We would like to thank Col Devraj Gill, Commandant and Ms Mitali Ambedkar, Sports Nutritionist of Sports Institute for support, helpful suggestions and discussions. Home About Us Editorial Board Issues Ahead of Print Current Issue Archives Ethical Guidelines Instructions For Authors For Reviewers Media and News Subscribe Contact Us Menu.

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Thank you for Ait nature. Displacemenf are using a displacemrnt version Air displacement assessment limited support for Metformin and insulin resistance. To Air displacement assessment the best experience, we recommend you asseswment a more up to date wssessment or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. This article introduces and evaluates the PEA POD Infant Body Composition System, an air displacement plethysmograph designed for the assessment of body composition in infants between birth and 6 mo of age. The performance of the PEA POD was evaluated by repeated testing of National Institute of Standards and Technology—traceable weights and volumes. Mass was measured in a single session.

Air displacement assessment -

This state represents average V TG during tidal breathing. V TG is therefore equal to functional residual capacity FRC plus approximately half of tidal volume V T. Historically, FRC has been measured using either helium dilution or plethysmographic assessment.

Helium dilution assessment of FRC in infants routinely gives lower values than those measured by plethysmography This difference results from trapped air in the lungs that cannot be detected by helium dilution The PEA POD uses a FRC prediction equation derived by plethysmographic assessment because any air in the lungs free or trapped is not part of the subject's body volume.

The following equation is used to predict FRC because it was derived recently using data from multiple centers 18 : MATH. V T values used by the PEA POD were also consolidated from multiple studies Interpolation is used when V T values need to be calculated at ages other than those presented.

After V T is determined, half of it is added to FRC to obtain V TG. The PEA POD uses the SAA and V TG expressed in liters to correct directly measured raw body volume V br.

Body volume V b is computed as follows: MATH. Note that SAA, a negative value by definition, is subtracted from V br and V TG is added to V br to arrive at V b. To illustrate with a typical example, a 1. Existing equations are not used because they were derived using fat-free mass density values specific to the adult population 10 , Equation 7 is solved for M f.

To solve Equation 7 for M f , D f and D ffm must be known. D f is constant throughout life and equal to 0. D ffm , however, changes during growth Age- and sex-specific D ffm values are used in Equation 7 and are obtained by extrapolating D ffm values presented in the literature for boys and girls at 0.

For boys, these values are 1. For girls, these values are 1. A complete PEA POD test is performed according to the following protocol. The subject's mass is measured on the PEA POD electronic scale.

Each time the PEA POD is moved and every 2 wk, the mass measurement is preceded by a scale calibration procedure to account for the unlikely possibility of drift in the system and changes in the acceleration as a result of gravity at different geographical locations.

A The scale output is then adjusted in case of a discrepancy. Simultaneous to the mass measurement, an automated volume calibration is performed. With the test chamber empty, pressure changes are collected while the calibration valve is closed and open.

The closing and opening of the calibration valve allows the system to perform a two-point calibration giving a linear relationship between the inverse ratio of the pressure perturbations in the two chambers and varying test chamber volumes.

The calibration procedure lasts 50 s, at the end of which the door automatically opens. Next, the tray is pulled out of the test chamber so that the subject can be placed in it. To start a test, the tray and subject are pushed back into the chamber, and the door is closed.

During the first 15 s of the test, a valve connecting the test chamber to the outside environment is opened, allowing the exchange of air between the test chamber and the outside environment.

This equilibration procedure is performed to avoid temperature-dependent deformations in the test chamber's walls resulting from heat generated by the subject. Pressure changes are then collected in the two chambers for 25 s.

Data collection ends with the automatic opening of the test chamber door. This procedure is performed a second time to test for consistency. If the two volume measurements are within 5 mL of each other or 0.

If this level of agreement is not reached, then a third measurement is performed. If the specified level of agreement is not reached after three measurements, then the entire testing procedure is repeated. First, the ability of the PEA POD to measure mass was determined by testing NIST-traceable weights with the following masses: 1, These weights had NIST Class F tolerances ± The weights tested during this study were representative of infants between birth and 6 mo of age.

During a single session, the mass of each weight was measured five times. Second, the ability of the PEA POD to measure volume was determined by testing aluminum cylinders after they had been added together to obtain the following volumes: 1, The accuracy of the linear dimensions of the cylinders tested was ±0.

This level of accuracy was obtained using instruments traceable to the NIST and in accordance with MIL-I and MIL-STDA standards. The range of volumes tested 1, Four sets of data were collected over 2 d. Each day was divided into a morning and an afternoon session.

All four sessions were performed with the same procedure. During each session, the above volumes were tested five times. Volume testing was performed in four separate sessions so that the reliability of the system could be assessed.

Results from sessions performed during the same day gave a measure of within-day reliability. Results from sessions performed during different days gave a measure of between-day reliability. With the exception of the mass measurement, each test followed the procedure described in the previous section.

The BSA values used for the SAA calculations were computed using the cylinders' known dimensions. No correction was performed for V TG because it applies only to in vivo testing. Mean values, as well as SD and coefficient of variation CV values for repeated mass measurements, are presented in Table 1.

The largest SD was 0. Table 2 presents the precision of the volume measurements. The SD and CV for repeated volume measurements within each session were 1. The mean values for both SD and CV were within very narrow ranges 1. Table 3 presents within- and between-day reliability of the volume measurements.

Within-day reliability is presented for day 1 sessions 1 and 2 and day 2 sessions 3 and 4. Between-day reliability is presented for session 1 of day 1 and session 3 of day 2, as well as session 2 of day 1 and session 4 of day 2.

Reliability is expressed as the mean of the CV values for each repeated trial performed on a particular volume or volumes in the specified sessions. Reliability was excellent with CV values for all measures of within- and between-day reliability equal to 0. Results from linear regression analyses of the PEA POD volume measurements against the volumes calculated from the cylinders' linear dimensions are displayed in Table 4.

Data are presented by session and with all four sessions combined. In all cases, the regression equations gave very low SEE 0. The regression analysis using combined data from all four sessions is illustrated in Figure 2. As can be seen, the system's linearity was excellent.

Linear regression of volume measurements by PEA POD using combined data from all four sessions versus the NIST-traceable volumes. Solid line is regression equation. Mean percentage volume errors are presented in Table 5.

The mean values and the SD and CV for repeated mass measurements presented in Table 1 indicate the exceptional precision and accuracy of the PEA POD scale. The SD and CV values for repeated measurements presented in Table 2 indicate a high precision for PEA POD volume measurements.

SD values ranged between 1. This level of precision is comparable to that shown by the BOD POD when used to measure the volume of inanimate objects 14 and well above the performance of other body composition methods designed for the infant population and evaluated with inanimate objects The between-day reliability shown by the PEA POD for the range of volumes tested, with mean CV values ranging from 0.

Results from linear regression analyses indicate a high agreement between the volumes measured by the PEA POD and the volumes computed from precisely measured linear dimensions. The magnitude of this error is well within the expected measurement variability for densitometry Even though the PEA POD demonstrates exceptional ability to measure the mass and volume of inanimate objects, this is only the first step.

It remains to be seen how the PEA POD performs with respect to the more challenging tasks of testing animal tissue samples varying in mass, volume, and fat content and, most important, living human infants.

This research is now under way. The advantages of the PEA POD include a testing sequence that is noninvasive, is fast, does not expose the subject to radiation, and does not require that the subject be sedated for a test. These characteristics, combined with the accuracy displayed in this study, demonstrate the potential of this technology to assess the body composition of infants.

This could lead to the development of a useful tool for researchers and clinicians involved in the nutritional assessment and management of infants. National Center for Health Statistics Division of Data Services.

Hyattsville, MD. National Health and Nutrition Examination Survey NHANES Prevalence of overweight and obesity among adults: United States, Accessed February 7, National Health and Nutrition Examination Survey NHANES Prevalence of overweight among children and adolescents: United States, Guo SS, Chumlea WC Tracking of body mass index in children in relation to overweight in adulthood.

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In: Stock J, Sly PD, Tepper RS, Morgan WJ eds Infant Respiratory Function Testing. Wiley-Liss, New York, — Stocks J, Marchard F, Kraemer R, Gutkowski P, Yishay EB, Godfrey S Plethysmographic assessment of functional residual capacity and airway resistance.

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You can also search for this author in PubMed Google Scholar. Correspondence to Alessandro Urlando. The research for this manuscript was supported by NIH Small Business Innovative Research Grants R43DK and R43DK from the National Institute of Diabetes and Digestive and Kidney diseases NIDDK.

The authors are employees of Life Measurement, Inc. Reprints and permissions. Urlando, A. A New Air Displacement Plethysmograph for the Measurement of Body Composition in Infants. Pediatr Res 53 , — Download citation. Received : 03 April Accepted : 06 November Issue Date : 01 March Anyone you share the following link with will be able to read this content:.

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nature pediatric research articles article. Download PDF. Although validated in healthy subjects, studies about use in pediatric patients are lacking. We evaluated user experience and usability of ADP measurements with the BOD POD system in healthy children and pediatric and young adult patients.

Technical performance was studied using the quality control data collected by the ADP-system. Results: From to , measurements were scheduled. BOD POD was mostly rated 'user-friendly', with a generally neutral evaluation on all scales of the UEQ.

Conclusion: We conclude that ADP by BOD POD in children and young adults is non-invasive and user-friendly.

Background: Accurate assesssment of Efficient fat utilization composition Dsplacement is important to investigate the development of Air displacement assessment obesity. Lycopene and aging bioelectrical assesdment analysis BIA device is portable and inexpensive compared with air displacement displxcement ADP for the assessment of BC and is widely used in children. However, studies of the effectiveness of BIA are few and present different results, especially in pediatric populations. The aim of this study was to evaluate the agreement between BIA and ADP for estimating BC. Methods: The BC of Chinese children 3—5 years was measured using the BIA device SeeHigher BAS-H, China and ADP BOD POD.

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Pea Pod: Infant Body Composition with Air Displacement Plethysmography technology Lycopene and aging combination of accuracy, safety and speed zssessment resulted in the BOD POD now being asseessment as the asxessment Gold Metabolic health forum for body Air displacement assessment assesssment from assessmentt long list of universities and Lycopene and aging centers. The ADP technology uses whole body densitometric principles to determine body composition Fat and Fat-Free Mass guaranteeing high accuracy and excellent test-retest repeatability. The BOD POD is designed for durability over time. An internal diagnostic function analyzes system performance and provides feedback to service personnel. BOD POD is provided with OMNIA, the modular software suite from COSMED with an innovative user interface. OMNIA intuitive workflow allows users to operate devices with no need for long learning paths. Read more.

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