Abstract
ABSTRACT: An acoustic plethysmograph designed to measure body volumes of infants is described. This method uses the principle of the Helmholtz resonator in which the resonant frequency of a chamber is inversely proportional to the square root of the volume of air inside the chamber. After an object is placed inside the chamber, the change in resonant frequency is used to measure the volume of the object. The coefficient of variation of repeated measures of body volumes of 13 miniature piglets (5 to 18 days old, body weights 1253 to 2631 g) ranged from 0.3 to 3.2%. Body volumes measured by the acoustic method agree closely with those calculated from carcass analysis in which body volume is the sum of the volumes of total body water, fat, protein, and minerals. Fat-free mass computed from densitometry using a four-compartment model and body volume measurements from the acoustic method agrees with fat-free mass obtained from carcass analysis. The mean difference between methods was not significant: 1 ml for body volume and 3 g for fat-free mass. The limits of agreement between methods was ± 75 ml for body volume and ± 214 g for fat-free mass. Our results indicate that the acoustic method can measure a change in body volume of 75 ml and a change in fat-free mass of 214 g in a 2000 g infant.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sheng, HP., Adolph, A., O'Brian smith, E. et al. Body Volume and Fat-Free Mass Determinations by Acoustic Plethysmography. Pediatr Res 24, 85–89 (1988). https://doi.org/10.1203/00006450-198807000-00020
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1203/00006450-198807000-00020
This article is cited by
-
Air-displacement plethysmography for determining body composition in neonates: validation using live piglets
Pediatric Research (2012)
-
Unrestrained Acoustic Plethysmograph for Measuring Tidal Volume in Mice
Annals of Biomedical Engineering (2006)