Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures

Abstract

In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework.

A novel augmented reality (AR) scheme for knee replacement surgery by considering cutting error accuracy

“…Along with this, the proposed solution with differential information about target shape and current shape helps to detect alignment and makes it easier to understand which areas need to be cut. This is a completely new feature adapted from the second‐best solution.…”

“…Inside the bounding box, a 2D image is overlaid onto the video frame , . An optical camera measures the history as the movement to the cutting tool, re‐examining the area that has been cut . Through volume subtraction, the remaining area to be cut is calculated.…”

“…This process is highly dependent on a precise cutting angle and orientation to insert the prosthesis to avoid that mechanical wear results in a negative effect on the patient's life. In this, AR supports navigation during the knee replacement as it superimposes the 3D model of the real organ onto the surgical area …”

“…For accurate surgical navigation, it is highly desirable to provide an accurate 3D model within the least possible operating time. In term of techniques, real‐time marker‐less registration, without fiducial marker, has achieved accuracy and speed up real‐time image registration. Research on the fiducial marker and bulky tracker has identified significant limitations in terms of errors and barriers to surgical setup.…”

“…Nakao proposed image augmentation that overlays shape changes to support bone cutting procedures on the spine where nerve structures are in contact with the vertebrae. Thus, reducing the cutting error even by 1 mm minimizes the risk of surgical incidents .…”