Computer-based training for minimal-invasive surgery

		Example setup: haptic device and virtual environment Haptic device developed at the LSRO for the training of gynaecologic intervention

Like a flight simulator for surgeons

Computer-assisted surgery simulation offers completely new possibilities, which have been long expected for medical training.

As each patient is different the surgeon faces at each intervention a unique and sometimes exceptional situation. Training is especially relevant for complex minimal-invasive or "keyhole" surgery techniques, where instruments are inserted through small incisions or natural openings into the patient.

The idea is quite simple: to provide a computer-scenery ("virtual-reality") on the screen and an artificial, but realistic force impression at the surgery tool handle with a so-called haptic device. The surgeon gets the information through the same perceptive channels, eye and hand, as in a real operation room scenario. While he manipulates the instruments in his hands, he can watch the displacements on the screen. In interaction with the simulated organs the surgeon can feel the contact forces at the tool handle.

Computer-assisted training has the potential to reduce cost in medical education, as scenario can be repeated as often as necessary. Both standard and critical situations can be provided. The organ anatomy and tissue behaviour can be adapted and changed in the computer program and, in case where patient data are available, pre-operative planning becomes possible. These are huge advantages over conventional training on single organs or animals.
As the simulator logs all actions during a simulation session, virtual-reality surgery simulators make it possible to evaluate the training effect or the performance based on predefined parameters.

For realistic surgery simulation the demands to force-feedback devices are high. The surgeon must be able to make all the movements of a real intervention and he has to feel realistic contact forces at the tool handle. Contact forces can vary within a wide range.

Surgery simulation with full force feedback

Within the Swiss research framework 'Co-Me' a simulator for gynaecology (hysteroscopy) is being developed. The simulator is intended to pave the way for performance assessment and evaluation, as well as for research on the characteristics, limitations and possibilities to enhance human performance in surgical procedures. One goal is to develop man-machine interfaces in order to create a highly advanced technological basis for the envisioned future generation of surgery simulators.

Another focus of the 'Co-Me' research network has been set toward the development of a surgery simulator for interventional radiology (IR). In this specific medical field, vascular diseases are diagnosed and treated by inserting catheters (sort of small tubes) and guide wires into the patient vascular tree. In that case, real-time X-ray images are used as visual feedback. As pre-operative planning tool such a simulator will not only enable training but will also help to develop, test and select catheters and guide wires for a specific intervention.

The computer-generated virtual reality models are provided by academic partners at ETHZ (CH), the CIMIT Group (Boston, USA) and by our spin-off and industrial partner xitact SA (Morges, CH). The Laboratoire de Systèmes Robotiques contributes the haptic- or force-feedback devices, which render the artificial contact forces at the surgery tool.