Monitoring electric field induced changes in biological tissue by using ultrasound

A new effect resulting from the application of an electric field to biomaterials was discovered by analyzing ultrasound echo signals. The new effect was observed in ex-vivo biological tissues such as porcine heart, muscle, fat, and liver and tissue mimicking phantoms for an electric field were on the order of a few Volt/cm. Changes in the arrival time of ultrasound echoes were processed using cross-correlation based algorithms. The gradient of shifting along the ultrasound axis showed a strain in the direction perpendicular to the applied electric field. The electric field also lead to changes in the ultrasound echo amplitude. The amount of the strain and the echo amplitude change depended on the history of the applied electric field. The new effect cannot be explained by resistive heating, piezoelectric effect, or electrostriction. It might be related to the electrokinetic effects.

Monitoring electric field induced changes in biological tissue by using ultrasound

A new effect resulting from the application of an electric field to biomaterials was discovered by analyzing ultrasound echo signals. The new effect was observed in ex-vivo biological tissues such as porcine heart, muscle, fat, and liver and tissue mimicking phantoms for an electric field were on the order of a few Volt/cm. Changes in the arrival time of ultrasound echoes were processed using cross-correlation based algorithms. The gradient of shifting along the ultrasound axis showed a strain in the direction perpendicular to the applied electric field. The electric field also lead to changes in the ultrasound echo amplitude. The amount of the strain and the echo amplitude change depended on the history of the applied electric field. The new effect cannot be explained by resistive heating, piezoelectric effect, or electrostriction. It might be related to the electrokinetic effects.

Experimental and Numerical Investigation of Heat Transfer Through Porcine Heart and Esophageal Tissue

Atrial fibrillation is a heart condition commonly treated by cardiac ablation procedures. Since the esophagus is positioned in close proximity to the heart, esophageal thermal damage can occur during ablation. In this study, we investigate the temperature rise on the inner esophagus surface using a 2D temperature sensor array. An experimental study was performed to measure temperature by the sensor array placed on inner porcine esophagus tissue as a constant temperature heat source is applied to the inner porcine atrial tissue. A numerical model was developed to complement the experimental study.