Does needle rotation improve lesion targeting?

Background: Image-guided robots are manipulators that operate based on medical images. Perhaps the most common class of image-guided robots are robots for needle interventions. Typically, these robots actively position and/or orient a needle guide, but needle insertion is still done by the physician. While this arrangement may have safety advantages and keep the physician in control of needle insertion, actuated needle drivers can incorporate other useful features. Methods: We first present a new needle driver that can actively insert and rotate a needle. With this device we investigate the use of needle rotation in controlled in-vitro experiments performed with a specially developed revolving needle driver. Results: These experiments show that needle rotation can improve targeting and may reduce errors by as much as 70%. Conclusion: The new needle driver provides a unique kinematic architecture that enables insertion with a compact mechanism. Perhaps the most interesting conclusion of the study is that lesions of soft tissue organs may not be perfectly targeted with a needle without using special techniques, either manually or with a robotic device. The results of this study show that needle rotation may be an effective method of reducing targeting errors.