Videos of early navigation system and video localizer from Alan Colchester

Note: These video clips were provided by

Dr. Alan Colchester, Professor of Clinical Neuroscience & Medical Image Computing Consultant Neurologist East Kent and Guy's & St. Thomas's Hospitals University of Kent.

Feel free to view them, but do not download and save them without express written permission of Dr. Colchester

Here is a bibliographic citation describing this work. Note the quite early date:

COLCHESTER1996] Colchester,A.C.F., Zhao, J., Holton-Tainter, K. S., Henri, C. J., Maitland, N., Roberts, P. T. E., Harris, C. G., and Evans, R. J. (1996) Development and preliminary evaluation of VISLAN, a surgical planning and guidance system using intra-operative video imaging. Medical Image Analysis 1: 73-90.

• 01-vislan-demo-video.avi
  • First part of movie: Preoperative system and construction of Pre-Operative Patient Representation (POPR) 1. Workstation display of POPR (Pre-Operative Patient Representation). Surface rendered recon from pre-op MRI. 2. Live video overlay: scalp mesh from stereo video + planned craniotomy site. 3. Phantom + localiser tracking. 4-pane view: Bottom right= projection view, with skull and tumour segmented from CT of phantom & icon showing “live” localiser location – stationary in this clip. Other panes= slice views of CT of phantom. 4. Video camera view of phantom with localiser held by operator – stationary in this clip. 5. MRI axial slice –with green line drawn roughly along midline (not sure what is the point of this clip). 6 & 7. Workstation display of POPR (Pre-Operative Patient Representation) and MRI. 4-pane view: Bottom right= projection view, with skin surface cut away and brain surface. Icon shows 3D cursor location; yellow (clip 6) indicates cursor position on or above rendered surface: black(clip 7) indicates cursor position below rendered surface. Other panes= slice views of MRI. 8. Workstation display of POPR, 4-pane view – all projections: skin surface; transparent skin surface transparent, with tumour shown beneath; transparent brain surface transparent, with tumour shown beneath; MR angio and tumour. 9. Workstation display of POPR and with movie of craniotomy being planned by operator, 4-pane view, as clip 8.
  • Second part of movie: Intra-Operative system, construction of Intra-Operative Patient Representation (IOPR), co-registration with POPR, and transfer of craniotomy plan (02:21 – 07:18) Mock-up of Operating Room, 10 (static) & 11 (movie, panning). a: Graphics workstations; b: skull phantom; c: localiser on table; d: stand with crossbar holding projector (central) and small video cameras at each end; d: live video monitor. 12 (left camera) and 13 (right camera): Video views from the two cameras, showing patterned light (uncalibrated) on face/ scalp of subject. 14. Workstation view of Intra-Operative Patient Representation: projection view of scalp reconstruction. POPR-IOPR Registration, workstation views: 15 (static), 16 (movie, intermediate) & 17: (movie, final registration) . User interface for intialisation and verfication. Workstation display of POPR, with planned craniotomy superimposed (static) (ends 05:26). 19. Video of phantom, to show transfer of planned craniotomy to subject (05:27 – 07:18). (a) phantom with skull “”intact”; (b) craniotomy plan superimosed on live video; (c) operator tracing craniotomy outline on phantom, by copying video overlay (ends 06:16). 20: Video of phantom after “craniotomy” (skull top removed). (a) view of tumour and vessels; (b) localiser in field of view, in different (static) positions; (c) (start at 06:25, end 06:59) localiser being moved by operator, with tracking points shown as dots overlaid on live video. 21: Video of phantom (starts 07:00) (a) tumour outline derived from CT i.e.“POPR” superimposed on video; (b) top of phantom skull being removed to show how tumour outline corresponds to tumour at skull base (ends 07:18).
  • Third part of movie: Localiser Tracking (also see later movies) (07:19 - 08:08) 22 (cf 23): Localiser tip on nasal feature, handle being moved by operator (start 07:19, end 07:29), with tracking points shown as dots overlaid on live video as in 20(c). 23 (cf 22): Workstation 4-pane display of POPR. Icon representing localiser superimposed on bottom right pane (static). 24 (cf 25): Video of localiser with tracking points superimposed, tip on phantom tumour (07:43 – 07:56). 25 (cf 24): Workstation 4-pane display of POPR. Icon representing localiser superimposed on bottom right pane (static) (ends 08:08).
  • Fourth part of move: Updating POPR-IOPR registration using markers attached to phantom skull. (08:08 - 09:49) 26 - 28: Video frames of phantom skull with markers attached. 26= first position, with craniotomy plan superimposed; 27= after moving phantom, with craniotomy plan correctly shifted to new location; 28= change in skull markers shown by bars linking positions before and after movement. 29: Video, repeating 26 – 27 “live” with drape over phantom: two deliberate displacements with automatic registration updating. Main movie ends at 09:49; logos and acknowledgements follow.
• 04-camera-and-mixed-01.avi
  • Live video with localiser being moved over surface of anthropomorphic phantom; dots overlaid on video show tracking of fiducials on the localiser handle. Each time the localiser is moved out of the field of view and then comes into view again, the video shows the delay while the localiser pattern is detected and the fiducial points are overlaid as bright dots. ( Note: the video is shown with low brightness to allow the overlaid points to be seen easily).
• 03-workstation-and-mixed-02.avi
  • 1. Workstation display: Anthropomorphic phantom + localiser tracking. (same as or similar to 02-workstation-and-mixed-01.avi) 4-pane view: Bottom right= projection view of skin surface segmented from CT of phantom & icon showing “live” localiser location. Other panes= slice views of CT of phantom, updated as localiser is being moved. Note: the yellow icon has marked colour bleeding.
  • 2. Split-screen movie starting 02:27 [seems to be same as second part of 03-workstation-and-mixed-05.avi]. Left half of movie screen shows live video with localiser being moved; dots overlaid on video show tracking of fiducials on the localiser handle. Right half of screen shows two panes of workstation display. Bottom pane = projection view of skin surface segmented from CT of phantom & icon showing “live” localiser location. Upper pane = sagittal slice views of CT of phantom, updated as localiser is being moved. From 04:44 – shows localiser being newly detected. Note: the yellow icon has marked colour bleeding.
• 06-vislan-clinical.avi
  • 1. Video of phantom. Surface view, then top removed to reveal objects inside to be used for accuracy measurement. 2. Mock-up of Operating Room, Trolley with workstation and video monitor; stand with cameras and projector, with phantom on table; Intra-Operative workstation menu screen. 3. Video view of phantom on table. 4. Calibration plate introduced into field, in two positions; . 5. Workstation again, showing menus. 6. Video of patterned light, views from each camera. 7 Rendered view of triangulated surface reconstruction; selection of initialisation points. 8. Workstation menu interaction again. 9. Video of surface tracing = alternative to patterned light for building IOPR surface model. 10. Workstation menu interaction again. 11. Workstation displays showing dot –pattern surfaces, for initialising and verifying POPR-to-IOPR registration. 12. Workstation menu interaction again. 13. Workstation POPR 3-pane display: orthogonal sections through CT scans of phantom. 13: Choice of pre-computed rendered views of projections of POPR objects. 14. Four-pane view now including POPR rendered view. 15. Workstation display. Selection of approximate POPR landmarks for registration initialisation. 15. Craniotomy plan shown on POPR workstation display. 16. Craniotomy plan shown as red outline superimposed on live video [marked colour bleeding]. 17. Live video of operator marking position of craniotomy on phantom surface by tracing overlay. 18. Workstation menu interaction again – selection of an additional POPR target object for display through transparent surface. 19. Live video with new object superimposed [colour poor]. 20. Live video with surface being removed to reveal interior object, showing correct alignment of video overlay. 21. Workstation menu interaction again – selecting option for real-time localiser updating. 22. Live video of localiser being moved over the surface of the phantom (cf clip23). 23. Workstation display of localiser being moved over the surface of the phantom as per 22 – was being updated concurrently with clip 22.
  • 1. Video of phantom. Surface view, then top removed to reveal objects inside to be used for accuracy measurement. 2. Mock-up of Operating Room, Trolley with workstation and video monitor; stand with cameras and projector, with phantom on table; Intra-Operative workstation menu screen. 3. Video view of phantom on table. 4. Calibration plate introduced into field, in two positions; . 5. Workstation again, showing menus. 6. Video of patterned light, views from each camera. 7 Rendered view of triangulated surface reconstruction; selection of initialisation points. 8. Workstation menu interaction again. 9. Video of surface tracing = alternative to patterned light for building IOPR surface model. 10. Workstation menu interaction again. 11. Workstation displays showing dot –pattern surfaces, for initialising and verifying POPR-to-IOPR registration. 12. Workstation menu interaction again. 13. Workstation POPR 3-pane display: orthogonal sections through CT scans of phantom. 13: Choice of pre-computed rendered views of projections of POPR objects. 14. Four-pane view now including POPR rendered view. 15. Workstation display. Selection of approximate POPR landmarks for registration initialisation. 15. Craniotomy plan shown on POPR workstation display. 16. Craniotomy plan shown as red outline superimposed on live video [marked colour bleeding]. 17. Live video of operator marking position of craniotomy on phantom surface by tracing overlay. 18. Workstation menu interaction again – selection of an additional POPR target object for display through transparent surface. 19. Live video with new object superimposed [colour poor]. 20. Live video with surface being removed to reveal interior object, showing correct alignment of video overlay. 21. Workstation menu interaction again – selecting option for real-time localiser updating. 22. Live video of localiser being moved over the surface of the phantom (cf clip23). 23. Workstation display of localiser being moved over the surface of the phantom as per 22 – was being updated concurrently with clip 22. Second part of movie, showing use of system in operating room (starts 11:45). 24. Logo. 25. Portable video taken in operating room (starts 11:56). Camera calibration. 26. Patterned light on patient’s scalp: video from one of the VISLAN cameras. 27. Workstation display: IOPR reconstruction; selection of initialisation landmarks 28. Live video of surface tracing (13:27 – 14:55). Not much action! 29. Live video, after craniotomy and preparation of surgical approach to deep-seated tumour. Long-tipped localiser inserted deep into operation site, to identify structures. 30. Workstation display combining POPR objects and MRI: Shows movement of localiser, as was updated in real time during 29 (ends 16:46). 31 & 32. Beginning of another clinical case I think. Shows localiser use (short-tipped version). Video then workstation display. Third part of movie, showing validation by phantom studies 33 & 34. Phantom study (18:24 – 19:45) to show localiser use. Video then workstation display. 35 et seq. Phantom study to demonstrate registration updating using marker pins (19:47 - 22:15)
  • Third part of movie, showing validation by phantom studies 33 & 34. Phantom study (18:24 – 19:45) to show localiser use. Video then workstation display. 35 et seq. Phantom study to demonstrate registration updating using marker pins (19:47 - 22:15)