Patent ID: 7684851

Claim:
A body cavity interior observing apparatus, comprising: a treating instrument which is inserted into a body cavity interior of an object to be examined includes a penetrating instrument as a guide; an observing section which is adapted to be mounted to an opening portion of a body wall of the object; a monitor which displays an image of the body cavity interior picked up by the observing section; a marker position detecting device for detecting a position of a marker attached to a distal end of the treating instrument from the image which shows the body cavity interior picked up by the observing section; a tracking device for tracking the position of the marker detected by the marker position detecting device to align the position of the marker to a central part of a screen of the monitor, a region separating section which separates the screen of the monitor into a tracked region which turns ON the tracking function of the tracking device and a non-tracked region which turns OFF the tracking function of the tracking device; a selecting device which selects at least one of a first non-tracked region which is positioned generally at the central part of the screen of the monitor and a second non-tracked region which is larger than the first non-tracked region, as the non-tracked region; wherein the region separating section switches between the first non-tracked region and the second non-tracked region based on a selection instruction from the selecting device, and when the marker is located in the non-tracked region, the tracking device does not align the position of the marker to the central part of the screen of the monitor.