PROJECT TITLE :

A Robust System for Longitudinal Knee Joint Edema and Blood Flow Assessment Based on Vector Bioimpedance Measurements

ABSTRACT:

We have a tendency to present a sturdy vector bioimpedance measurement system for longitudinal knee joint health assessment, capable of acquiring high resolution static (slowly varying over the course of hours to days) and dynamic (rapidly varying on the order of milli-seconds) bioresistance and bioreactance signals. Occupying an area of seventy eight×90 mm2 and consuming 0.25 W when supplied with ±5 V, the front-finish achieves a dynamic range of 345 Ω and noise floor of 0.018 mΩrms (resistive) and 0.05five mΩrms (reactive) among a bandwidth of 0.one-20 Hz. A microcontroller permits real-time calibration to attenuate errors thanks to environmental variability (e.g., temperature) that may be experienced outside of lab environments, and allows information storage on a micro secure digital card. The acquired signals are then processed using customized physiology-driven algorithms to extract musculoskeletal (edema) and cardiovascular (local blood volume pulse) features from the knee joint. During a feasibility study, we found statistically vital differences between the injured and contralateral static knee impedance measures for two subjects with recent unilateral knee injury compared to seven controls. Specifically, the impedance was lower for the injured knees, supporting the physiological expectations for increased edema and damaged cell membranes. In a second feasibility study, we tend to demonstrate the sensitivity of the dynamic impedance measures with a cold-pressor test, with a 20 mΩ decrease within the pulsatile resistance associated with increased downstream peripheral vascular resistance. The proposed system can serve as a foundation for future efforts aimed toward quantifying joint health status continuously throughout normal everyday life.