title: Control of a hybrid robotic system for computer-assisted interventions in dynamic environments.
abstract: OBJECTIVE
  Minimally invasive surgery is becoming the standard treatment of care for a variety of procedures. Surgeons need to display a high level of proficiency to overcome the challenges imposed by the minimal access. Especially when operating on a dynamic organ, it becomes very difficult to align instruments reliably and precisely. In this paper, a hybrid rigid/continuum robotic system and a dedicated robotic control approach are proposed to assist the surgeon performing complex surgical gestures in a dynamic environment.
  
  
  METHODS
  The proposed robotic system consists of a rigid robot arm on top of which a continuum robot is mounted in series. The continuum robot is locally actuated with McKibben muscles. A control scheme based on quadratic programming framework is adopted. It is shown that the framework allows enforcing a set of constraints on the pose of the tip, as well as of the instrument shaft, which is commanded to slide in and out through the entry point.
  
  
  RESULTS
  Through simulation and experiments, it is shown how the robot tool tip is able to follow sinusoidal trajectories of 0.37 and 2 Hz, while maintaining the instrument shaft pivoting along the entry point. The positioning and tracking accuracy of such system are shown to lie below 4.7 mm in position and [Formula: see text] in angle.
  
  
  CONCLUSIONS
  The results suggest a good potential for applying the proposed technology to assist the surgeon during complex robot-assisted interventions. It is also illustrated that even when using flexible hence relatively safe end-effectors, it is possible to reach acceptable tracking behaviour at relatively high frequencies.
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium. gabrijel.smoljkic@kuleuven.be.
authors.forename: Gabrijel
authors.initials: G
authors.lastname: Smoljkic
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Gianni
authors.initials: G
authors.lastname: Borghesan
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Alain
authors.initials: A
authors.lastname: Devreker
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Emmanuel Vander
authors.initials: EV
authors.lastname: Poorten
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Benoit
authors.initials: B
authors.lastname: Rosa
authors.affiliation: Cardiac surgery, UZ Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Herbert
authors.initials: H
authors.lastname: De Praetere
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Joris
authors.initials: J
authors.lastname: De Schutter
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Dominiek
authors.initials: D
authors.lastname: Reynaerts
authors.affiliation: Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, 3001, Leuven, Belgium.
authors.forename: Jos Vander
authors.initials: JV
authors.lastname: Sloten
mesh_terms: D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation / Q000379:methods; D056888:Patient Positioning; D065287:Robotic Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods
keywords: Constraint-based control; Continuum robot; Heart surgery; Motion compensation; Transapical valve implantation