Apparatus for Measuring Human Body Volume

TLDR

Measuring whole‑body density or volume is essential for reliable human fat estimation. The study develops a less demanding method for measuring human body volume. The apparatus uses a closed‑circuit two‑chamber gas‑dilution system where helium concentration measured by thermal conductivity reflects the subject’s tissue volume displacement. The method achieves a volume determination standard deviation of ±0.12 L.

Abstract

A means for measuring the density or the volume of the whole body is essential to reliable estimates of fat in humans. Although Archimedes' principle has often been employed to determine density directly, a method that is less demanding on the subject has been developed for measuring body volume. The apparatus is a closed-circuit system consisting of two chambers and utilizing a gas-dilution principle. With the subject in one chamber and helium in the other, the gases in the system are mixed. The helium concentration, measured by thermal conductivity, is related to the tissue volume displacement of the subject. The standard deviation in volume determination is estimated as ±0.12 liter.