Effect of applied pressure on bioimpedance measurements of ex-vivo human lung tissue

Abstract The contrast in the electrical properties of healthy and malignant lung tissue could provide a methodology for intraoperative surgical margin assessment to reduce positive margins and improve clinical outcomes. However, the tissue is often compressed and deformed during intraoperative procedures. This study explores the impact applied pressure has on the electrical properties of ex vivo human lung tissue. Impedance spectra spanning 100 Hz to 10 MHz were recorded from freshly resected lung tissue specimens including lesion (n=3), perilesion (n=3), and healthy (n=4) samples, under an applied load and converted into resistivity. A linear regression was performed for each resistivity-pressure curve for all tissue types. A significant difference (p<0.05) was found between regression coefficients of lesion and perilesion tissues and both regression coefficient and constant for lesion and healthy tissue. No significant differences were found between the perilesion and healthy tissue coefficient or constant. These finding suggests that resistivity increases with pressure at different rates for malignant and healthy tissue that may be sufficient for surgical margin assessment.