In this paper we present a system of computer assisted surgery, the fu
nction of which is to enhance the real time feedback between the patie
nt's body, the surgical tools and the surgeon. We show using such a sy
stem during some surgical operations-in our case, retroperitoneoscopy.
After giving the requirements for such a system, we describe the comp
onents currently used in our experiments. We detail the different prob
lems and our current solutions; photographs of an experiment carried o
ut on a cadaver and of classical operations are shown in this paper.