Dedication of Bioelectric Impedance Analysis(BIA)

Professional BIA Body Composition Analysis

Body composition analysis describes what the body is made of, differentiating between body water, protein, minerals, and fat to provide more precise information beyond weight and BMI. Charder's devices use Bioelectrical Impedance Analysis (BIA), for fast, simple, non-invasive, and easily repeatable analysis. Boasting multiple measurement frequencies and sophisticated algorithms, Charder stands by our devices with clinical trials and over ten years of original peer-reviewed scientific research, for results you can trust.

What is Bioelectrical Impedance Analysis (BIA)?

What is Bioelectrical Impedance Analysis (BIA) ?

Charder uses Bioelectrical Impedance Analysis (BIA) to estimate body composition. At its core, the concept of BIA is based on the differing electrical conductivity of body tissue. For example, electrolyte-containing body water is a good conductor of electricity, whereas fat acts as an insulator. The properties of body tissue allow for differentiation and determination of body composition.

Multi-frequency measurement

Multi-frequency measurement

Traditional BIA devices estimate body composition using one frequency (50kHz is most commonly used). The frequency of the current affects the resistance of biological conductors. Because low frequencies have difficulty overcoming and passing through cell membranes, they are well-suited for measurement of extracellular water. High frequency currents can pass through cell membrane walls, making it possible to measure intracellular water.

That’s why Charder’s Body Composition Analyzers use multiple frequencies, using direct measurements to provide more detailed analysis of body composition, particularly relating to body water balance, which is a crucial output parameter when it comes to disease management and rehabilitation.

Precise Segmental Analysis and Multiple Body Composition Parameters

Charder’s dedicated research into BIA has culminated in an accurate measurement method that can measure muscle and fat in the trunk, upper limbs, and lower limbs with a high degree of accuracy.

Charder’s Body Composition Analyzers can analyze measured data to output multiple body composition parameters, including:

Multi-measurement Parameters

  • Total and segmental lean mass analysis
  • Abdominal fat analysis - Visceral and Subcutaneous fat
  • Muscle Quality
  • Bioelectrical Impedance Vector Analysis (BIVA)
  • Phase Angle percentiles
  • Percent Body Fat percentiles
  • Skeletal Muscle Index as an indicator of sarcopenia
  • Edema Index
Bioelectirc Impedance Vector Analysis

Bioelectrical Impedance Vector Analysis (BIVA)

In medical settings, quick, accurate, and cost-effective evaluation of a patient’s hydration status is a critical part of diagnostics and treatment. Conventional BIA uses regression equations to produce estimates of Total Body Water, Extra- and Intracellular Water. However, because equations are formulated based on “normal” healthy populations and rely upon assumptions about standard hydration level, accuracy of these estimates may vary based on disparity between the subject and comparison population. This is where Bioelectrical Impedance Vector Analysis (BIVA) comes in.

BIVA assesses fluid status and body cell mass through Resistance (R) and Reactance (Xc). Assuming that resistance correlates with body fluid, and reactance correlates with body cell mass, R and Xc are normalized for height, and compared with the reference population. Because R and Xc – unlike body composition estimates – are directly determined by body fluid volume, BIVA can be used as an accurate assessment tool by subjects with abnormal hydration levels, who might not be able to rely upon conventional BIA results.

Phase angle as a health indicator

Most BIA parameters describe quantity in a subject. The amount and proportion of body water. The amount of fat. The amount of muscle mass. Charder utilizes the capacitive properties of cell membranes to provide phase angle analysis. When an electric current passes through a cell, a phase shift between current and voltage occurs, causing a time difference that can be measured in degrees by Charder’s Body Composition Analyzers.

A higher phase angle correlates with stronger cell membranes, and as such phase angle has been accepted as a general health indicator.

Phase angle and health determinants

High Correlation with DXA

Charder has partnered closely with universities and research institutes for many years as part of its dedication to BIA research, methodologically validating measurement algorithms with clinical research, showing a positive correlation coefficient of r=0.95 with DXA.

Body Composition Analyzer

Validation Studies

  • KC Hsieh, JJ Chao, CS Wu, HK Lu. Discrepancy BMD between Taiwan First Division Football League players and healthy men by DXA. Journal of Strength Conditioning Research, June 2017, Submitted. (SCI)
  • CS Wu, YY Chen, LC Lee, KH Lu, JJ Chao, KC Hsieh*. The validation of bioelectrical impedance analysis system in evaluating segmental body composition in soccer players, Journal of Exercise Science & Fitness, August 2017, Under review. (SCI)
  • YS Liao, HC Li, LW Lee, YL Kuo, HK Lu, CL Lai, YS Wang, KC Hsieh. Validation of a portable eight‐electrode multi‐frequency bioelectrical impedance analysis using dual‐energy X‐ray absorptiometry as a reference. Aug 2017, Clinical Nutrition, Under review. (SCI)
  • KT Chen, YY Chen, CL Chuang, HK Lu, LM Chiang, CL Lai, KM Casebolt, AC, WL Lin, Huang, KC Hsieh*. Discrepancies between leg‐to‐leg bioelectrical impedance analysis and computerized tomography in abdominal visceral fat measurement. Scientific reports, 2017, 7(1):9102. (SCI)
  • LW Lee, YS Liao, HK Lu, PL Hsiao, YY Chen, CC Chi, KC Hsieh*. Validation of two portable bioelectrical impedance analyses for the assessment of body composition in school age children. PLOS One, 2017, 12(2), e0171568. (SCI)
  • MF Chen, YY Chen, TR Jang, WL Lin, J Chen, KC Hsieh*. Total body composition Estimated by a standing‐posture 8‐electrode bioelectrical impedance analysis in young Taiwanese male wrestlers, Biology of Sport, Dec 2016; 33:399‐405. (SCI)
  • AC Huang, YY Chen, CL Chuang, LM Chiang, HK Lu, HC Lin, KT Chen, AC Hsiao, KC Hsieh*. Cross‐mode bioelectrical impedance analysis in a standing position for estimating fat free mass validated against dual‐energy X‐ray absorptiometry. Nutrition Research, 2015; 35: 982‐989. (SCI)