A New Phantom that Simulates Electrically a Human Blood Vessel Surrounded by Tissues: Development and Validation Against In-Vivo Measurements.

This study aims to develop a phantom that simulates the electrical properties of a human blood vessel surrounded by tissues, inside which bubbles can be infused to mimic Decompression Sickness (DCS) conditions. This phantom may be used to calibrate novel electrical methods for bubbles detection in humans and study bubble dynamics during DCS. It may contribute to the limitation of in-vivo trials and time/effort saving, while its use can be extended to other biomedical applications. To facilitate the design of the phantom, we perform first in-vitro measurements in a flow-loop and in-vivo measurements in a swine, in order to detect infused bubbles of a few tenths μm-representing Decompression Sickness conditions-in the test liquid flow and blood flow, respectively, by means of "I-VED" EU patented electrical impedance spectroscopy technique. Results show that the proposed phantom, consisting of a spongy specimen soaked in agar gel in the presence of electrolyte with a hole along it, simulates adequately the electrical properties of a human blood vessel surrounded by tissues. I-VED demonstrates pretty high sensitivity to sense micro-bubbles over the partially conductive vessel walls of the phantom or the isolated animal vein, as well as in the flow-loop: bubbles presence increases electrical impedance and causes intense signal fluctuations around its mean value.