Patent ID: 8298135

Claim:
A medical device, comprising: an endoscope with an insertion section that is insertable through a tube cavity in a subject, the insertion section having a channel formed therein, the insertion section having an opening of the channel at a distal end portion of the insertion section; an image pickup section that is able to pick up an image of the tube cavity in the subject, the image pickup section being disposed at the distal end portion of the insertion section; a medical instrument for examination or treatment in the tube cavity, the medical instrument being insertable through the channel, the medical instrument being configured to protrude from the distal end portion of the insertion section through the opening; a virtual endoscopic image generation section configured to generate a virtual endoscopic image of the tube cavity from a plurality of different line-of-sight positions using three-dimensional image data of the tube cavity that is obtained in advance; an image retrieval section configured to retrieve the virtual endoscopic image highly similar to the endoscopic image of the tube cavity in a body picked up by the image pickup section; a reference-point setting section configured to set a reference point based on a line-of-sight position of the highly similar virtual endoscopic image, wherein the reference point is positioned at the opening; a relative-position calculation section configured to calculate a relative position of the medical instrument to the reference point; a movement detection section configured to detect a movement of the reference point or the subject; and a position correction section configured to correct the relative position in response to the movement of the reference point or the subject detected by the movement detection section.