Device size selection support system for minimally invasive cardiac surgery

In mitral valve reconstruction, an annuloplasty band is sutured the patient's valve to restore valve function. The size of the band is determined intraoperatively by inserting a measuring device. However, the insertion of the measuring device is difficult in minimally invasive surgery with small incisions, which has become popular in recent years. We previously proposed a system that superimposes a virtual image of a valve ring on an endoscopic image using AR (Augmented Reality) technology to assist in surgery. However, the system was limited to superimposing a virtual image of a ring on an endoscopic image taken from a single viewpoint. In this study, therefore, a more accurate simulation that can be checked from various directions based on 3D shape data. First, the 3D information of the marker area is estimated using stereo method. Next, the spectral reflectance is estimated from color images obtained from a stereo endoscope and marker areas are extracted. Finally, the annuloplasty band automatically selected from 3D positions of the markers is displayed on the 3D simulation. To evaluate this method, we performed the spectral reflectance estimation and 3D simulation using a pig heart marked with surgical maker and confirmed its effectiveness. This system enables size selection without inserting measuring instruments during surgery and is expected to shorten the operation time.