Surgery assistance device and surgery assistance program

A surgery assistance device configured to display a simulation image during surgery performed by inserting an endoscope into the interior of a surgical instrument, the surgery assistance device comprising:

• a tomographic image information acquisition section configured to acquire tomographic image information;
• a memory that is connected to the tomographic image information acquisition section and configured to store voxel information related to the tomographic image information;
• a volume rendering computer that is connected to the memory and configured to sample voxel information in a direction perpendicular to the sight line on the basis of the voxel information;
• and
• a display controller configured to set a first display area acquired by the endoscope and produced by the volume rendering computer, and a second display area in which display is restricted by the surgical instrument during actual surgery, and display the first and the second display areas on a display section.