Relationship Between Body Posture and Lung Fluid Volume Assessed Using a Novel Noninvasive Remote Dielectric Sensing System

Abstract

Background: The relationship between body posture and lung fluid level has not been quantified thus far. Remote dielectric sensing (ReDSTM) is a recently introduced non-invasive electromagnetic-based technology to quantify lung fluid percentage. Methods and Results: ReDS values were measured at different body postures (i.e., sitting, supine, and supine with legs elevated) in a healthy volunteer cohort (n=16; median age 39 years, 69% men, median [interquartile range {IQR}] body mass index 23.3 kg/m2 [21.0-26.2 kg/m2]). In the sitting position, the median ReDS value was 27% (IQR 25-29%). The ReDS value increased significantly in the supine position (median 28%; IQR 27-30%; P=0.009), and increased further upon leg elevation (median 29%; IQR 28-32%; P=0.001). Conclusions: In this proof-of-concept study, the relationship between body posture and lung fluid level was quantitatively validated in a healthy cohort.

Keywords: Congestion; Heart failure; Hemodynamics.

Conflict of interest statement

T.I. receives grant support from JSPS KAKENHI (JP20K17143). The remaining authors have no conflicts of interest to report. K.K. is an Editorial Board member of Circulation Reports.

Copyright © 2022, THE JAPANESE CIRCULATION SOCIETY.

Figures

Figure 1.

(A) A remote dielectric sensing (ReDSTM) system consisting of a monitor and a sensor unit. (B) Representative image of actual measurements using the ReDS system.

Figure 2.

Schema of the 3 body postures in which remote dielectric sensing (ReDSTM) measurements were conducted in this study.

Figure 3.

Remote dielectric sensing (ReDSTM) values measured at 3 different body positions. The boxes show the interquartile range, with the median value indicated by the horizontal line; whiskers show the range. Asterisks indicated P values obtained using the Friedman test; daggers indicate P values obtained using the Wilcoxon signed-rank test.