engleski

Real time transfer of live video image in parallel with volume 3D-models of te surgical field in Tele-3D-computer assisted surgery

The use of minimally invasive surgical methods such as Functional Endoscopic Sinus Surgery (FESS) and Tele-FESS has imposed the need of as reliable as possible preoperative imaging of the spatial anatomic relationship in the respective region. In the region of paranasal sinuses, such an image is of paramount importance for the surgeon or tele-expert-surgeon because of the proximity of intracranial structures and limited operative field layout hampering spatial orientation during the operative procedure. The last and very natural step of technology implementation in the operating room (OR) is to connect the computer workstations and video equipment to remote locations using a high speed & wide bandwidth computer network. During patient preparation, the surgeon in the OR consults remote, experienced and skilful surgeons using computed thomography images and three-dimensional models on computer workstations. The surgeon and consultants use software for computed thomography image previews and three-dimensional model manipulations on top of collaboration tools to define the pathology, to produce an optimal path to the pathology and to decide how to perform the real surgical procedure. Using tele-fly-through or tele-virtual endoscopy via three-dimensional models, both surgeons can preview all the characteristics of the region (anatomy ; pathology) and so predict and determine the next steps of the operation. This ensures higher safety of the operation guidance and reduces the possibility or intraoperative error. The duration of the tele-consultation is thus shortened, which may prove the greatest benefit from Tele-three-dimensional computer assisted surgery. By this way clinical institutions would spend less money for time fees for telesurgical consultation. During our pilot projects, Three dimensional computer assisted functional endoscopic sinus surgery (3D-CA-FESS) and Tele-3D-CA-FESS, we designed a computer assisted 3D-approach in presurgical planning, intraoperative guidance and postoperative analysis of anatomical regions of the nose and paranasal sinuses. Such an extremely powerful approach allowed us a better insight into the operating field including significantly greater safety of the procedure itself. We used several standards to encode live video signals in telesurgery, such as M-JPEG, MPEG1 and MPEG2. It has been definitely concluded that MPEG2 streams, without audio, have the best picture quality for the operating field/endo camera. For conferencing/consultation cameras used between two or more connected sites during the surgery, we used JPEG and MPEG1 stream with audio. Operating rooms were connected using several computer network technologies with different bandwidths, from T1, E1 and multiple E1 to ATM-OC3 (from 1Mb/s to 155Mb/s). For computer communications using X-protocol for image/3D-models manipulations, we needed an additional 4Mb/s of bandwidth, instead of the 1Mb/s when we used our own communication tools for the transfer of surgical instrument movements. The bandwidth for the transfer in one direction of one MPEG2 stream without audio and one MPEG1 with audio was about 10MB/s.

real time; live video image; volume 3D-models; surgical field; telemedicine; 3D; computer assisted surgery

doi:10.1089/153056204323057013