title: Computational modeling and prototyping of a pediatric airway management instrument.
abstract: BACKGROUND
  Anterior retraction of the tongue is used to enhance upper airway patency during pediatric fiberoptic intubation. This can be achieved by the use of Magill forceps as a tongue retractor, but lingual grip can become unsteady and traumatic. Our objective was to modify this instrument using computer-aided engineering for the purpose of stable tongue retraction.
  
  
  METHODS
  We analyzed the geometry and mechanical properties of standard Magill forceps with a combination of analytical and empirical methods. This design was captured using computer-aided design techniques to obtain a 3-dimensional model allowing further geometric refinements and mathematical testing for rapid prototyping.
  
  
  RESULTS
  On the basis of our experimental findings we adjusted the design constraints to optimize the device for tongue retraction. Stereolithography prototyping was used to create a partially functional plastic model to further assess the functional and ergonomic effectiveness of the design changes. To reduce pressure on the tongue by regular Magill forceps, we incorporated (1) a larger diameter tip for better lingual tissue pressure profile, (2) a ratchet to stabilize such pressure, and (3) a soft molded tip with roughened surface to improve grip.
  
  
  CONCLUSIONS
  Computer-aided engineering can be used to redesign and prototype a popular instrument used in airway management. On a computational model, our modified Magill forceps demonstrated stable retraction forces, while maintaining the original geometry and versatility. Its application in humans and utility during pediatric fiberoptic intubation are yet to be studied.
authors.affiliation: Department of Anesthesiology. University of Michigan Health System, 1H247 UH, SPC 5048 1500 East Medical Center Drive, Ann Arbor, MI 48109-5048, USA. alancota@med.umich.edu
authors.forename: Alan
authors.initials: A
authors.lastname: Gonzalez-Cota
authors.forename: Grant H
authors.initials: GH
authors.lastname: Kruger
authors.forename: Padmaja
authors.initials: P
authors.lastname: Raghavan
authors.forename: Paul I
authors.initials: PI
authors.lastname: Reynolds
mesh_terms: D000465:Algorithms; D000776:Anesthesiology / Q000295:instrumentation*; D002648:Child; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design / Q000379:methods*; D006804:Ergonomics; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D019563:Mechanics; D008953:Models, Anatomic; D015233:Models, Statistical; D008962:Models, Theoretical; D055100:Optical Fibers; D013525:Surgical Instruments; D014059:Tongue / Q000033:anatomy & histology*