Proposal for Remote Robot Programming in ENT Surgery
Telepresence Research Institute, Vienna, Austria
A.R. Gunkel, W. Freysinger, W.F. Thumfart
Clinic for ENT, University of Innsbruck, Austria
email: email@example.com, http://www.artma.com
work in progress
In computer aided maxillofacial surgery we have shown the feasibility of telenavigation for a wide variety of indications [1, 2]. The superimposition of a guiding path with live video from the endoscope  during operation provides useful information even for the experienced surgeon. We explore the extension of our work  to position intraoperatively the endoscope with robotic arm assistance as first step to a robot assisted surgery concept.
At the local operating theater the patient is scanned in the CT with a special head frame in place prior to surgery. Also with the head frame in place a manually guided exploratory access of the endoscope to the endonasal cavity is recorded in the computer system as digital video sequence . This data is the basis for defining the planned access path for the robot guided endoscope position.
All further steps of patient image coordinate transformation, simulation of an access path for the robot guided endoscope and intraoperative modifications of the endoscope position are performed at a remote expert location, thus dramatically reducing the complexity of the intraoperative manipulation.
Prior to surgery the CT data set and the digitally recorded video sequence are sent over a network to the remote expert. 3D sensors are attached to the head frame and to the endoscope and to all surgical instruments. This system is already calibrated in itself because the sensor position relative to the fiducial markers on the frame is constant. For the patient image coordinate transformation at the remote site only the fiducial markers on the CT are correlated with the corresponding markers on the head frame. The remote expert defines an access path to the endonasal cavity based on the CT data. Although the CT data is the basis for the planning of the positioning of the endoscope the access path and the actual position is verified based on stereotactic video image data.
During surgery the endoscopic live video and the stereotactic coordinates of instruments are sent via the network in real time to the remote expert. In addition to the video he can follow the procedure by visualizing the position of these instruments relative to the coronar slices of the patient. The position of the endoscope relative to the patients anatomy is also visualized as projection of an overlay on the volumetric 3D CT reconstruction. The head of the patient is tracked by a 3D sensor, the robot guided endoscope remains in a defined position relative to the patients anantomy. Any proposed change of the endoscope position is visualized by the remote expert relative to this 3D visualization first before sending a navigation command to the operating theater.
Summary: We propose a new approach for remote programming the access path and position of a robot guided endoscope. It is intuitive for a non technical user and based recorded video sequences. Our proposed method makes it possible to perform all calibration and simulation steps at a remote site, thus shielding the surgeon completely from the complexity of the technology. Stereotactically recorded video sequences are used as reference for navigation of the robot, supplementing the CT data. Intraoperatively the robot guided endoscope can be remotely repositioned based on live video imaging data. We want to explore the initial potential of remote robot guided ENT surgery in training and education.
W. Millesi, M. Truppe, F. Watzinger, A. Wagner, and R. Ewers, "Image Guided Surgery Extended by Remote Stereotactic Visualization," presented at CVRmed - MRCAS 97, Grenoble, 1997.
M. Truppe, "EURODOC (European Initiative for Remote Knowledge Visualization)," presented at CVRmed - MRCAS 97, Grenoble, 1997.
M. Truppe, "Process for imaging the interior of bodies," European Patent Office 1993, patent WO94/03100.
R. Gunkel, W. Freysinger, W. F. Thumfart, and M. Truppe, "Application of the ARTMA Image-Guided Navigation System to Endonasal Sinus," presented at Computer Assisted Radiology, Berlin, 1995.
M. Truppe, F. Pongracz, W. Freysinger, A. Gunkel, and W. Thumfart, "Interventional Video Tomography," presented at Computer Assisted Radiology, Berlin, 1995.