An endoscope shape detection system has a CPU included in a control unit.
The CPU performs frequency sampling of digital data to calculate
coordinates indicating the spatial positions of source coils incorporated
in an insertion unit of an endoscope received in a patient and of marker
coils placed on a patient. An inserted state of the insertion unit of the
endoscope is estimated based on the calculated coordinate data indicating
the positions of the source coils. Display data based on the shape of the
endoscope is produced from the calculated coordinate data indicating the
positions of the source coils, and output to a video RAM. Display data of
the marker coils is produced from the calculated coordinate data
indicating the positions of the marker coils, and output to the video RAM.
Consequently, the positions of the markers are depicted together with the
shape of the endoscope. The positional relationship between the insertion
unit of the endoscope and a patient's body can therefore be ascertained.
