Electric currents have differing penetration abilities depending on their frequency. Some frequencies are better suited for measuring body water outside the cell, while others are capable of passing through cell membranes and measuring total body water. InBody makes use of multiple currents at varying frequencies in order to provide most precise body water analysis results.
InBody uses low frequencies and high frequencies to penetrate the cell membrane and accurately analyze both extracellular water and intracellular water. By using multiple frequencies, InBody devices are able to accurately measure total body water and are suitable for analyzing individuals with imbalanced body water distributions.
By using multiple currents set at different frequencies, InBody devices are able to provide precise information about body composition because many resistance values are attained. The InBody 770, for example, uses a total of six different frequencies to measure each segment, providing a total of 30 separate impedance values. This allows the InBody 770 to measure body composition with a very high degree of accuracy.
Direct Segmental Multi-frequency Bioelectrical Impedance Analysis
Modern BIA views the human body as five “cylinders”: the arms, the legs, and the trunk. Accurate and independent measurements of each cylinder are essential for providing analysis not just for each cylinder, but for the entire body. InBody’s advanced technology allows all InBody devices to directly measure all five cylinders.
The trunk contains essential internal organs, and its metabolic characteristics are different from the other parts of the body. In terms of impedance, it is important to precisely and directly measure the trunk because resistance values in the trunk are much lower than those in the arms and legs. This means that the margin of error for trunk measurements must be controlled as much as possible.
Impedance values in the arms and legs generally range between 200~500Ω, while the values for the trunk are between 20~30Ω. Despite its low impedance, the trunk accounts for 50% of Lean Body Mass. Because the impedance values for the arms and legs range in the hundreds, an error of 1~2Ω will have a negligible effect on the final measurement. However, a 1~2Ω error in the trunk can cause significant miscalculations when determining results for the trunk. Therefore, overall body composition can only be accurately calculated when even slight changes in the impedance of the trunk can be detected. For this reason, accurate and direct trunk measurements are essential for determining body composition.
InBody’s patented design separates the current-emitting and voltage-detecting electrodes, which allows impedance to be measured in the area where current flow and voltage measurement overlap. Using DSM-BIA, InBody can determine the impedance values of the arms, legs and trunk. This technology was first developed by InBody and is protected by patents in various countries around the world.
Conventional BIA devices, by contrast, employ the “Whole Body Impedance” measurement method, which only reports a single impedance value for the entire body. This is an imprecise and dated method because it cannot directly measure trunk impedance, which is essential for accurate measurements.
No Empirical Estimations
Empirical data, such as data related to age and gender, are values that are achieved through observation. Estimations that use empirical data have been used to improve the accuracy in BIA devices that measure impedance using the Whole Body Impedance method. Although useful for measuring the typical and/or healthy body type, problems occur when measuring individuals that have atypical body types, such as high performance athletes or severely overweight individuals. InBody avoids this problem altogether by completely avoiding any use of empirical estimations.
Because InBody’s advanced technology allows for the direct and precise measurement of each of the body’s five segments, including the trunk, InBody devices do not require or take into account any empirical data when producing results. It is unnecessary. The only information InBody requires to determine body composition are height, weight, and impedance. This makes InBody suitable for testing atypical body types. InBody always provides correct results regardless of gender, age, or race. If an individual tests on an InBody device, and immediately re-tests with a different age or gender, that individual will receive the same results on their second test as they did the first.