Phase Segmentation Methods for an Automatic Surgical Workflow Analysis

Table 10

Average calculation time of each step in all methods for a test surgical workflow (12.8 minutes of length).

Method	Foreground detection (milliseconds per frame)	OF extraction (milliseconds per frame)	LDA (seconds per workflow)	Feature normalization (milliseconds per workflow)	HMM (milliseconds per workflow)
FrameDiff_GridBlock_Top	4.7	176.3	4.7	61.0	7.6
FrameDiff_GridBlock_means	4.7	176.3	4.7	57.0	23.1
MultiCue_GridBlock_Top	17.7	1070.0	10.1	79.0	9.7
MultiCue_GridBlock_means	17.7	1070.0	10.1	74.0	24.6
FrameDiff_GridIntersect_Top	4.7	8.4	0.9	54.0	14.2
FrameDiff_GridIntersect_means	4.7	8.4	0.9	57.0	20.5
MultiCue_GridIntersect_Top	17.7	12.2	6.3	71.0	12.6
MultiCue_GridIntersect_means	17.7	12.2	6.3	69.0	24.2