title: Data-derived models for segmentation with application to surgical assessment and training.
abstract: This paper addresses automatic skill assessment in robotic minimally invasive surgery. Hidden Markov models (HMMs) are developed for individual surgical gestures (or surgemes) that comprise a typical bench-top surgical training task. It is known that such HMMs can be used to recognize and segment surgemes in previously unseen trials. Here, the topology of each surgeme HMM is designed in a data-driven manner, mixing trials from multiple surgeons with varying skill levels, resulting in HMM states that model skill-specific sub-gestures. The sequence of HMM states visited while performing a surgeme are therefore indicative of the surgeon's skill level. This expectation is confirmed by the average edit distance between the state-level "transcripts" of the same surgeme performed by two surgeons with different expertise levels. Some surgemes are further shown to be more indicative of skill than others.
authors.affiliation: Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA. bvarada2@jhu.edu
authors.forename: Balakrishnan
authors.initials: B
authors.lastname: Varadarajan
authors.forename: Carol
authors.initials: C
authors.lastname: Reiley
authors.forename: Henry
authors.initials: H
authors.lastname: Lin
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Khudanpur
authors.forename: Gregory
authors.initials: G
authors.lastname: Hager
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004521:Educational Measurement / Q000379:methods*; D006801:Humans; D019060:Minimally Invasive Surgical Procedures / Q000193:education*; D008962:Models, Theoretical; D010363:Pattern Recognition, Automated / Q000379:methods*; D011361:Professional Competence; D012371:Robotics / Q000193:education*; D025321:Surgery, Computer-Assisted / Q000193:education*; D013647:Task Performance and Analysis; D014481:United States