title: A sub-millimetric, 0.25 mN resolution fully integrated fiber-optic force-sensing tool for retinal microsurgery.
abstract: OBJECTIVE
  Retinal microsurgery requires extremely delicate manipulation of retinal tissue where tool-to-tissue interaction forces are usually below the threshold of human perception. Creating a force-sensing surgical instrument that measures the forces directly at the tool tip poses great challenges due to the interactions between the tool shaft and the sclerotomy opening.
  
  
  METHODS
  We present the design and analysis of a force measurement device that senses distal forces interior to the sclera using 1-cm long, 160 microm diameter Fiber Bragg Grating (FBG) strain sensors embedded in a 0.5 mm diameter tool shaft. Additionally, we provide an algorithm developed to cancel the influence of environmental temperature fluctuations.
  
  
  RESULTS
  The force-sensing prototype measures forces with a resolution of 0.25 mN in 2 DOF while being insensitive to temperature.
  
  
  CONCLUSIONS
  Sub-millinewton resolution force sensors integrated into microsurgical instruments are feasible and have potential applications in both robotic and freehand microsurgery.
authors.affiliation: Johns Hopkins University, CSEB 112, Baltimore, MD 21218, USA. iordachita@jhu.edu
authors.forename: Iulian
authors.initials: I
authors.lastname: Iordachita
authors.forename: Zhenglong
authors.initials: Z
authors.lastname: Sun
authors.forename: Marcin
authors.initials: M
authors.lastname: Balicki
authors.forename: Jin U
authors.initials: JU
authors.lastname: Kang
authors.forename: Soo Jay
authors.initials: SJ
authors.lastname: Phee
authors.forename: James
authors.initials: J
authors.lastname: Handa
authors.forename: Peter
authors.initials: P
authors.lastname: Gehlbach
authors.forename: Russell
authors.initials: R
authors.lastname: Taylor
mesh_terms: D002138:Calibration; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006801:Humans; D008866:Microsurgery / Q000295:instrumentation*; D012164:Retinal Diseases / Q000601:surgery*; D012590:Sclera / Q000601:surgery; D025321:Surgery, Computer-Assisted / Q000379:methods*