title: A method for identifying otological drill entanglement with a cotton swab.
abstract: BACKGROUND
  The entanglement of the otological drill with cotton swabs is a common milling fault in ear surgery. To improve operational safety, this paper presents a method for identifying this type of milling fault.
  
  
  METHODS
  Force and current sensors were installed on a modified otological drill. In accordance with the DC motor model and cutting force model, two features of the milling process were extracted, namely the characteristic curve and the dynamic relationship between the sensor signals. These are complementary features. An adaptive filter was designed to fuse them together and output a curve that was sensitive to milling faults and was stable during normal milling. Based on the filtering data, a rule base is presented for identifying cotton swab entanglement.
  
  
  RESULTS
  Five surgeons were invited to perform an experiment on calvarian bones. The average recognition rate for milling faults was 90%, whereas only 2% of normal millings were identified as milling faults.
  
  
  CONCLUSIONS
  The presented method could adapt to the technique of different surgeons and identify milling faults exactly.
authors.affiliation: School of Automation & Electrical Engineering, University of Science & Technology Beijing .
authors.forename: Tianyang
authors.initials: T
authors.lastname: Cao
authors.forename: Xisheng
authors.initials: X
authors.lastname: Li
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Guodong
authors.initials: G
authors.lastname: Feng
authors.forename: Peng
authors.initials: P
authors.lastname: Shen
mesh_terms: D004574:Electromagnetic Fields; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005547:Foreign Bodies; D006801:Humans; D010036:Otolaryngology / Q000295:instrumentation / Q000379:methods*; D013506:Otologic Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D012449:Safety; D012984:Software; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D013784:Textiles; D019415:Torque