Quantitative analysis of applied force on biopsy needle insertions

Abstract

Purpose: The major drawback of conventional computed tomography (CT)-guided biopsy is the exposure of the operator to radiation during the procedure. One of the solutions to this problem is the biopsy utilizing modern robotic technology with the assistance of imaging technology. Methods: In the design of a biopsy robot system, the structure and the size of the needle manipulator need to be optimized based on the quantitative analysis of the magnitude and pattern of the axial force applied during a biopsy. In this study, simulated biopsy experiments were conducted using the biopsy robot system previously developed at the National Cancer Center of Korea. The magnitude and the pattern of the axial forces applied to the needle insertion device located at the end of the slave arm were measured while varying the shape, diameter, and insertion angle of the biopsy needle and the specimen for biopsy. Results: The results showed that the amount and the pattern of the axial force applied to the biopsy needle are affected by the physical properties of the biopsy specimen as well as the tip shape, diameter, and insertion angle of the needle. These results will facilitate the optimization of the required workspace, size, and weight of robot systems for robotic biopsy. Conclusions: A quantitative analysis was performed to examine changes in the shape, diameter, and insertion angle affect the force on the biopsy needle. We found that the force applied on the needle might vary depending on the physical characteristics of the various internal organs and structures. © 2012 Korean Society of Medical and Biological Engineering and Springer.