title: Toward robot-assisted vascular microsurgery in the retina.
abstract: BACKGROUND
  Experimental protocol in our laboratory routinely requires the precise placement of instruments at, or near, the retina. Although manipulators for placing an instrument within the eye presently exist, none of the designs were satisfactory due to limitations on size, accuracy and operability. To overcome these limitations, we have developed a novel six degree of freedom manipulator designed specifically for retinal microsurgery.
  
  
  METHODS
  The manipulator is parallel in structure and provides submicrometer positioning of an instrument within the constrained environment of the eye. The position of an instrument attached to the manipulator is commanded by the operator using a hand-held trackball. A computer controller interprets the trackball input and moves the manipulator in an intuitive manner according to mathematically constrained modes of operation.
  
  
  RESULTS
  Over 50 retinal vessels in the live, anesthetized cat have been successfully cannulated for pressure measurement and drug injection using the described manipulator and micropuncture techniques. The targeted vessels ranged in internal diameter from 20 to 130 microns.
  
  
  CONCLUSIONS
  This device has applications in microsurgery where tremor and fatigue limit the performance of an unaided hand and where mechanically constrained manipulators are inappropriate due to size and operative constraints.
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Jensen
authors.forename: K W
authors.initials: KW
authors.lastname: Grace
authors.forename: R
authors.initials: R
authors.lastname: Attariwala
authors.forename: J E
authors.initials: JE
authors.lastname: Colgate
authors.forename: M R
authors.initials: MR
authors.lastname: Glucksberg
mesh_terms: D000818:Animals; D002415:Cats; D004867:Equipment Design; D008866:Microsurgery / Q000295:instrumentation* / Q000379:methods; D012171:Retinal Vessels / Q000601:surgery*; D012371:Robotics / Q000295:instrumentation / Q000379:methods; D013813:Therapy, Computer-Assisted