title: Development of a device for real-time light-guided vocal fold injection: A preliminary report.
abstract: OBJECTIVE
  Vocal fold injection is a minimally invasive technique for various vocal fold pathologies. The shortcomings of the cricothyroid (CT) membrane approach are mainly related to invisibility of the injection needle. If localization of the needle tip can be improved during vocal fold injection with the CT approach, the current problems of the technique can be overcome. We have conceptualized real-time light-guided vocal fold injection that enables simultaneous injection under precise localization. In this study, we developed a device for real-time light-guided vocal fold injection and applied it in excised canine larynx.
  
  
  METHODS
  Animal model.
  
  
  METHODS
  A single optic fiber was inserted in an unmodified 25-gauge needle. A designated connector for the device was attached to the needle, the optic fiber, and the syringe. A laser diode module was used as the light source. An ex vivo canine larynx model was used to validate the device.
  
  
  RESULTS
  The location of the needle tip was accurately indicated, and the depth from the mucosa could be estimated according to the brightness and size of the red light. The needle was inserted and could be localized in the canine vocal fold by the light of the device. Precise injection at the intended location was easily performed with no manipulation of the device or the needle.
  
  
  CONCLUSIONS
  Real-time light-guided vocal fold injection might be a feasible and promising technique for treatment of vocal fold pathology. It is expected that this technique can improve the precision of vocal fold injection and expand its indication in laryngology.
  
  
  METHODS
  NA.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University Hospital, Busan, Korea.|Biomedical Research Institute, Pusan National University Hospital, Busan, Korea.
authors.forename: Wonjae
authors.identifier: http://orcid.org/0000-0001-7292-9474
authors.initials: W
authors.lastname: Cha
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Pusan National University, Busan, Korea.
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Ro
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University Hospital, Busan, Korea.
authors.forename: Soo-Geun
authors.initials: SG
authors.lastname: Wang
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University Hospital, Busan, Korea.
authors.forename: Jeon Yeob
authors.initials: JY
authors.lastname: Jang
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University Hospital, Busan, Korea.
authors.forename: Jae Keun
authors.initials: JK
authors.lastname: Cho
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University Hospital, Busan, Korea.
authors.forename: Geun-Hyo
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University Hospital, Busan, Korea.
authors.forename: Yeon Woo
authors.initials: YW
authors.lastname: Lee
mesh_terms: D000818:Animals; D004285:Dogs; D004867:Equipment Design; D005336:Fiber Optic Technology; D006820:Hyaluronic Acid; D007267:Injections / Q000295:instrumentation; D008297:Male; D023421:Models, Animal; D009339:Needles; D014827:Vocal Cords
chemical_list: D006820:Hyaluronic Acid
keywords: Vocal fold injection; injection laryngoplasty; laser; light guided; optic fiber; transcutaneous