title: Force requirements for artificial muscle to create an eyelid blink with eyelid sling.
abstract: OBJECTIVE
  To determine the force requirements, optimal vector, and appropriate materials of a novel eyelid sling device that will be used to rehabilitate eyelid closure (blink) in congenital or acquired permanent facial paralysis with an artificial muscle.
  
  
  METHODS
  The force required to close the eyelids in human cadavers (n = 6) were measured using a load cell system. The eyelid sling using either expanded polytetrafluoroethylene (ePTFE) or temporalis muscle fascia was implanted. The ideal vector of force and placement within the eyelid for a natural eyelid closure were compared.
  
  
  RESULTS
  The eyelid sling concept was successful at creating eyelid closure in a cadaver model using an upper eyelid sling attached to the distal tarsal plate. Less force was necessary to create eyelid closure using a temporalis muscle fascia sling (627 +/- 128 mN) than for the ePTFE eyelid sling (1347 +/- 318 mN).
  
  
  CONCLUSIONS
  The force and stroke required to close an eyelid with the eyelid sling are well within the attainable range of the electroactive polymer artificial muscle (EPAM). This may allow the creation of a realistic and functional eyelid blink that is symmetric and synchronous with the contralateral, normally functioning blink. Future aims include consideration of different sling materials and development of both the EPAM device and an articulation between the EPAM and sling. The biocompatibility and durability studies of EPAM in a gerbil model are under way. The successful application of artificial muscle technology to create an eyelid blink would be the first of many potential applications.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California, Davis Medical Center, Sacramento, 95817, USA.
authors.forename: Craig W
authors.initials: CW
authors.lastname: Senders
authors.forename: Travis T
authors.initials: TT
authors.lastname: Tollefson
authors.forename: Shane
authors.initials: S
authors.lastname: Curtiss
authors.forename: AnnJoe
authors.initials: A
authors.lastname: Wong-Foy
authors.forename: Harsha
authors.initials: H
authors.lastname: Prahlad
mesh_terms: D001767:Blinking / Q000502:physiology*; D005123:Eye; D005143:Eyelids / Q000601:surgery*; D006801:Humans; D018482:Muscle, Skeletal / Q000601:surgery*; D011138:Polytetrafluoroethylene; D019919:Prosthesis Implantation / Q000379:methods*; D013703:Temporal Muscle / Q000637:transplantation*; D014743:Videotape Recording
chemical_list: D011138:Polytetrafluoroethylene