title: Skeleton-based active catheter navigation.
abstract: BACKGROUND
  The emergence of the active catheter has prompted the development of catheterization in minimally invasive surgery. However, it is still operated using only the physician's vision; information supplied by the guiding image and tracking sensors has not been fully utilized.
  
  
  METHODS
  In order to supply the active catheter with more useful information for automatic navigation, we extract the skeleton of blood vessels by means of an improved distance transform method, and then present the crucial geometric information determining navigation. With the help of tracking sensors' position and pose information, two operations, advancement in the proximal end and direction selection in the distal end, are alternately implemented to insert the active catheter into a target blood vessel.
  
  
  RESULTS
  The skeleton of the aortic arch reconstructed from slice images is extracted fast and automatically. A navigation path is generated on the skeleton by manually selecting the start and target points, and smoothed with the cubic cardinal spline curve. Crucial geometric information determining navigation is presented, as well as requirements for the catheter entering the target blood vessel. Using a shape memory alloy active catheter integrated with magnetic sensors, an experiment is carried out in a vascular model, in which the catheter is successfully inserted from the ascending aorta, via the aortic arch, into the brachiocephalic trunk.
  
  
  CONCLUSIONS
  The navigation strategy proposed in this paper is feasible and has the advantage of increasing the automation of catheterization, enhancing the manoeuvrability of the active catheter and providing the guiding image with desirable interactivity.
authors.affiliation: School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang Province, People's Republic of China.
authors.forename: Yili
authors.initials: Y
authors.lastname: Fu
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.forename: Shuguo
authors.initials: S
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
authors.forename: Xianling
authors.initials: X
authors.lastname: Li
authors.forename: Zhaoguang
authors.initials: Z
authors.lastname: Liang
mesh_terms: D001013:Aorta, Thoracic / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D001808:Blood Vessels / Q000033:anatomy & histology; D002404:Catheterization / Q000295:instrumentation / Q000379:methods*; D003198:Computer Simulation; D006801:Humans; D021621:Imaging, Three-Dimensional; D008280:Magnetics; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011859:Radiography; D012371:Robotics / Q000295:instrumentation / Q000379:methods*; D012985:Software Design; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*