title: Addressing multi-label imbalance problem of surgical tool detection using CNN.
abstract: OBJECTIVE
  A fully automated surgical tool detection framework is proposed for endoscopic video streams. State-of-the-art surgical tool detection methods rely on supervised one-vs-all or multi-class classification techniques, completely ignoring the co-occurrence relationship of the tools and the associated class imbalance.
  
  
  METHODS
  In this paper, we formulate tool detection as a multi-label classification task where tool co-occurrences are treated as separate classes. In addition, imbalance on tool co-occurrences is analyzed and stratification techniques are employed to address the imbalance during convolutional neural network (CNN) training. Moreover, temporal smoothing is introduced as an online post-processing step to enhance runtime prediction.
  
  
  RESULTS
  Quantitative analysis is performed on the M2CAI16 tool detection dataset to highlight the importance of stratification, temporal smoothing and the overall framework for tool detection.
  
  
  CONCLUSIONS
  The analysis on tool imbalance, backed by the empirical results, indicates the need and superiority of the proposed framework over state-of-the-art techniques.
authors.affiliation: Zuse Institute Berlin, Berlin, Germany. sahu@zib.de.
authors.forename: Manish
authors.identifier: http://orcid.org/0000-0003-2158-823X
authors.initials: M
authors.lastname: Sahu
authors.affiliation: Zuse Institute Berlin, Berlin, Germany.
authors.forename: Anirban
authors.initials: A
authors.lastname: Mukhopadhyay
authors.affiliation: Zuse Institute Berlin, Berlin, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Szengel
authors.affiliation: Zuse Institute Berlin, Berlin, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Zachow
mesh_terms: D000465:Algorithms; D004724:Endoscopy / Q000379:methods*; D005547:Foreign Bodies / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016571:Neural Networks, Computer; D010363:Pattern Recognition, Automated / Q000379:methods*
keywords: CNN; Laparoscopic videos; Multi-label learning; Surgical tool detection; Transfer learning