Development of a needle insertion manipulator for central venous catheterization

Background: Central venous catheterization is a procedure in which a doctor inserts a catheter into a patient's vein for transfusions. Risks of this procedure include bleeding from the puncture of blood vessels and pneumothorax caused by pleural puncture. To avoid these and other risks, physicians are required to ensure that the needle is inserted securely and that it stops within the vein. Methods: We propose a robotic system for assisting venous puncture that is capable of alleviating the difficulties encountered during the conventional procedure, as well as minimizing the risks of complications. This paper describes the design and results of experiments conducted using a needle insertion manipulator. First, we investigated the relation between insertion force and angle into the vein to determine the appropriate insertion angle in relation to the blood vessel under physical conditions. The results indicated that the reaction force can be used to gauge whether the needle has been inserted into the vein in cases where the insertion angle is in the range 10-20°. Based on this result, we determined the mechanisms of the puncture device, which comprises a small, compact configuration. Experiments for accuracy validation were performed on a phantom. Results: We evaluated the positioning accuracy using ultrasound images, and the results indicated an accuracy of 1.0mm or better, which is considered feasible for venous puncture. In the phantom experiments, we confirmed that our manipulator was capable of placing the needle within the vein. Conclusions: The feasibility of this system was demonstrated in our experiments. Further studies, such as in vivo experiments, are required.