Virtual pneumoperitoneum for generating virtual laparoscopic views based on volumetric deformation

This paper describes a method for generating virtual pneumoperitoneum based on volumetric deformation and its application to virtual laparoscopy. Laparoscopic surgery is now widely performed as a minimum-invasive surgery. Because a laparoscope has a very narrow viewing area, this limits the surgeon's viewable area. Making views that the abdominal wall is virtually elevated (virtual pneumoperitoneum) will be very helpful for intra-operative surgical navigation or pre-operative surgical planning. We deform original 3-D abdominal CT images so that the abdominal wall is virtually elevated. The entire process consists of five major steps: (a) extracting the abdominal wall, (b) elastic modeling, (c) elastic deformation of the model, (d) deformation of the original image, and (e) rendering virtual laparoscopic images. Virtual laparoscopic images are then generated from the deformed image. We have applied the method to three cases of 3-D abdominal CT images. From the experimental results, we confirmed that the abdominal wall was appropriately elevated by the proposed method. Laparoscopic views were very helpful for intra-operative surgical navigation as additional views of a surgeon or pre-operative surgical planning.