Dynamic fluid phantoms for impedance plethysmography-a proof-of-concept study

Abstract

Impedance plethysmography (IPG) is a non-invasive sensing technique to assess variations in fluid volumes based on changes in bioelectrical impedance. While physical impedance phantoms are quite common for other methods such as electrical impedance tomography, they are rare for IPG. In fact, IPG investigations require a dynamic system with conductive blood and tissue simulants. Such a dynamic fluid phantom might provide well-defined test scenarios toward more sophisticated analysis methods. In this study, we investigated different phantom designs made from aquagel and silicone. In both cases, we were able to obtain timevarying impedance signals, which qualitatively correspond to the recorded fluid dynamics. While the aquagel phantom showed mechanical limitations, the silicone phantom appears promising for further research. These results represent a step toward a more comprehensive dynamic fluid phantom for impedance or even multi-modal sensing.