Method with repeated extraction-insertion cycles to improve the needle insertion accuracy

In order to improve the effectiveness of percutaneous diagnosis and therapies, the needle insertion into the deforming soft and inhomogenous tissue should be accurate. In this study a needle with 6 degrees of freedom force/torque sensor is used to find the relationship between the pathway＇s length and the force. Our experiments show that the method with repeated extraction-insertion cy- cles can make the needle approach the target as much as possible. Meanwhile a method to obtain the appropriaterepeated extraction-insertion cycles is given to drive the needle to execute the repeat- ed cycles efficiently. Experiments and discussions were conducted to preliminarily validate the meth- od.