title: Flexible robotics with electromagnetic tracking improves safety and efficiency during in vitro endovascular navigation.
abstract: One limitation of the use of robotic catheters is the lack of real-time three-dimensional (3D) localization and position updating: they are still navigated based on two-dimensional (2D) X-ray fluoroscopic projection images. Our goal was to evaluate whether incorporating an electromagnetic (EM) sensor on a robotic catheter tip could improve endovascular navigation.
  
  
  
  Six users were tasked to navigate using a robotic catheter with incorporated EM sensors in an aortic aneurysm phantom. All users cannulated two anatomic targets (left renal artery and posterior "gate") using four visualization modes: (1) standard fluoroscopy mode (control), (2) 2D fluoroscopy mode showing real-time virtual catheter orientation from EM tracking, (3) 3D model of the phantom with anteroposterior and endoluminal view, and (4) 3D model with anteroposterior and lateral view. Standard X-ray fluoroscopy was always available. Cannulation and fluoroscopy times were noted for every mode. 3D positions of the EM tip sensor were recorded at 4 Hz to establish kinematic metrics.
  
  
  
  The EM sensor-incorporated catheter navigated as expected according to all users. The success rate for cannulation was 100%. For the posterior gate target, mean cannulation times in minutes:seconds were 8:12, 4:19, 4:29, and 3:09, respectively, for modes 1, 2, 3 and 4 (P = .013), and mean fluoroscopy times were 274, 20, 29, and 2 seconds, respectively (P = .001). 3D path lengths, spectral arc length, root mean dimensionless jerk, and number of submovements were significantly improved when EM tracking was used (P < .05), showing higher quality of catheter movement with EM navigation.
  
  
  
  The EM tracked robotic catheter allowed better real-time 3D orientation, facilitating navigation, with a reduction in cannulation and fluoroscopy times and improvement of motion consistency and efficiency.
authors.affiliation: DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, Tex. Electronic address: aschwein@houstonmethodist.org.
authors.forename: Adeline
authors.initials: A
authors.lastname: Schwein
authors.affiliation: Department of Mechanical Engineering, Rice University, Houston, Tex.
authors.forename: Ben
authors.initials: B
authors.lastname: Kramer
authors.affiliation: Siemens Medical Solutions USA Inc, Hoffman Estates, Ill.
authors.forename: Ponraj
authors.initials: P
authors.lastname: Chinnadurai
authors.affiliation: Hansen Medical Inc, Mountain View, Calif.
authors.forename: Sean
authors.initials: S
authors.lastname: Walker
authors.affiliation: Department of Mechanical Engineering, Rice University, Houston, Tex.
authors.forename: Marcia
authors.initials: M
authors.lastname: O'Malley
authors.affiliation: DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, Tex.
authors.forename: Alan
authors.initials: A
authors.lastname: Lumsden
authors.affiliation: DeBakey Heart and Vascular Center, Houston Methodist Hospital, Houston, Tex.
authors.forename: Jean
authors.initials: J
authors.lastname: Bismuth
mesh_terms: D001014:Aortic Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography; D055590:Electromagnetic Phenomena; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D005240:Feasibility Studies; D005471:Fluoroscopy; D006801:Humans; D021621:Imaging, Three-Dimensional; D059346:Magnets; D008422:Materials Testing; D008953:Models, Anatomic; D009048:Motor Skills; D061646:Operative Time; D011446:Prospective Studies; D011829:Radiation Dosage; D000069079:Radiation Exposure; D011857:Radiographic Image Interpretation, Computer-Assisted; D012077:Renal Artery / Q000000981:diagnostic imaging; D065287:Robotic Surgical Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D013647:Task Performance and Analysis; D013997:Time Factors; D014159:Transducers; D062666:Vascular Access Devices