Evolution of stereoscopic imaging in surgery and recent advances

Table 3 Dual channel laparoscopes - Screen projection and glasses

Ref.	Year	Projection system for 3D	Who and what assessed	Objective outcomes	Subjective outcomes
Birkett et al[26]	1994	Active shuttering screen and Active glasses then polarised glasses vs 2D	10 Subjects? experience 2 × lab based skills tasks	Time take for repetitive cycles; No difference in simples task, reduced time in complex task	NA
Peitgen et al[29]	1996	Active shuttering screen and glasses	60 subjects (20 novices, 20 beginners, 20 advanced laparoscopic surgeons) 2 × lab based skills tasks	Time and accuracy of tasks Both significantly improved in 3D, independent of experience	NA
Wentink et al[30]	2002	Active shuttering screen and polarised glasses vs TFT display vs projection vs standard (2D)	8 surgeons with laparoscopic experience Lab based skills task	Time for task completion, 10 repetitions but only 2 surgeons per visual system No improvement with 3D	Felt image quality poorer with 3D
Jourdan et al[31]	2004	Active shuttering screen and glasses	8 experienced laparoscopic surgeons 5 × lab based skills tasks	Time and errors, 10 repetitions each, in each visual system Significant improvement in both in 3D	NA
Feng et al[32]	2010	Active shuttering screen and polarised glasses (SD vs 2D SD vs 2D HD)	27 subjects (16 novices, 11 with varying laparoscopic experience) Lab based skills task	Time and economy of movement Time significantly improved over both 2D systems in 3D, economy of movement improved in 3D vs HD, not SD 2D	Felt improved depth perception in 3D
Hubber et al[33]	2003	Prototype passive polarising screen and glasses	16 Medical Students (novices) Lab based skills tasks	Time and performance (ICSAD) Improvements in 3D significant over 2D	NA
Honeck et al[34]	2012	Passive polarising screen and glassed	10 novices and 10 experienced laparoscopic surgeons 5 × lab based skills tasks	Time and errors (1 × repetition, in only 1 of the visual systems) No significant improvement in time, reduction in errors significant in both groups in 3D	No impairment felt in subjective feedback when using the 3D system
Smith et al[35]	2012	Passive polarising screen and glassed	20 novices 4 × lab based skills tasks	Time and errors (10 repetitions of each task in each visual condition) Significant improvement in time and errors in 3D	NA
Bilgen et al[36]	2013	Passive polarising screen and glassed	3 surgeons Clinical - 11 laparoscopic cholecystectomies performed in 3D (compared to 11 performed retrospectively in 2D)	Time Significant reduction in time when performed in 3D, compared to case matched lap choles performed previously in 2D	NA
Sinha et al[37]	2013	Passive polarising screen and glassed	Retrospective analysis of 451 clinical gynaecological surgery performed in 3D Case matched assessment of 200 hysterectomies performed in 3D vs 2D	Time Significant reduction in operating time and morcellation time when performed in 3D	NA
Cicione et al[38]	2013	Passive polarising screen and glassed	33 subjects (10 experts and 23 novices) 5 × lab based skills tasks (Basic Laparoscopic Urological Skills)	Time and errors Overall, significant improvement in time and errors (although experts only improved time in 1 task in 3D)	Subjective Questionnaire - felt tasks were easier in 3D universally
Lusch et al[39]	2014	Passive polarising screen and glassed	24 subjects (10 medical students, 7 residents, 7 expert surgeons) 6 × lab based skills tasks	Time and errors 4 out of 5 skills tasks had significantly improved time and errors when done in 3D, independent on experience	Optical resolution and depth perception improved in 3D
Smith et al[40]	2014	Passive polarising screen and glassed	20 experienced surgeons 4 × lab based skills tasks	Time and errors (10 repetitions of each task in each visual condition) Significant improvement in time and errors in 3D	Subjective assessments using NASA Task Load Index - improvements with 3D all sections

NA: Not available; 3D: Three-dimensional; 2D: Two-dimensional; HMD: Head mounted display.