Optical Measurement of Tissue Deformation in Needle Insertion

This study develops an optical measurement method to investigate the tissue deformation in needle insertion. Accurate needle insertion with sub-mm accuracy to the target position is desired in various clinical procedures but challenging in practice. One of the main challenges is tissue deformation caused by needle insertion force, introducing the undesired target movements. The double-layered tissue phantom is explored to enable the optical measurement of tissue deformation. Images of tissue deformation were analysed by Kanade-Lucas-Tomasi feature tracking algorithm and digital image correlation technique to measure tissue movement and strain, respectively. This method was further utilized to compare the tissue deformation under different needle insertion speeds. Results show that higher insertion speed increases the tissue deformation due to the increased friction force while reducing the strain perpendicular to the insertion direction near the needle tip. The findings offer insights on tissue deformation and needle-tissue interaction. This study demonstrates the potential of this method to evaluate tissue deformation for various needle designs and insertion motions.