Surgical robots require high precision in intraoperative registration. Relying solely on their own navigation and positioning capabilities is not sufficient; they need to be combined with mobile 3D flat panel C-arm imaging to enhance navigation accuracy.
Mobile 3D Flat Panel C-arm
Unlike the spiral CT used in radiology scanning rooms, mobile 3D flat panel C-arm employs cone-beam CT scanning equipment, typically seen in devices like 3D C-arms and O-arms. So, how does mobile 3D flat panel C-arm assist surgical robots in completing surgical navigation?
Let’s take the example of how the mobile 3D flat panel C-arm (PLX C7600) assists in spinal surgery to introduce the four steps involved in the surgical process.
(1) Intraoperative Image Acquisition
Intraoperative navigation can utilize either C-arm or MRI images. In orthopedic surgeries, where bone anatomical precision is crucial, intraoperative C-arm images are more commonly used compared to intraoperative MRI. Mobile 3D flat panel C-arm is particularly favored in these scenarios.
Navigation technology based on fluoroscopy is similar to C-arm-based navigation technology, allowing multiple intraoperative fluoroscopic images to be uploaded to the workstation for 3D reconstruction. The latest fluoroscopy-based navigation technology can perform real-time reconstruction based on preoperative C-arm data, thereby displaying the patient’s actual anatomical structure during surgery.
(2) Motion Capture
Surgical navigation requires a motion capture system to track the spatial movement of surgical instruments and display these movements on the screen in real-time. Optical tracking technology is commonly used in spinal surgery navigation for motion capture.
The optical motion capture system relies on optical cameras to accurately measure the spatial position of objects through triangulation. To ensure the accuracy of real-time surgical navigation, it’s essential to avoid obstructing the optical cameras during the surgery.
By utilizing the motion capture system, surgical navigation can track the position and trajectory of surgical instruments in space, recognizing their translation and rotation in the coordinate system in real-time.
(3) Image Registration
Before the surgery begins, the surgical navigation system needs to correlate the anatomical structure captured in intraoperative images with the patient’s actual anatomy, aiding the surgeon in image-guided surgery. Image registration is the process of aligning the coordinates of the captured images with the navigation tracking system to provide a “map” for surgical navigation.
For instance, in Perlove Medical’s spinal surgery navigation system, the system automatically completes image coordinate establishment and system coordinate registration by tracking the C-arm’s 3D acquisition trajectory. This method is not affected by image quality. Compared to ruler-based registration, trajectory registration offers higher precision, fewer operational steps, and greater system efficiency.
(4) Image Visualization
Once the image registration is complete, the surgical navigation system overlays the virtual image of the surgical instrument onto the intraoperative 3D images. As the surgeon moves the real surgical instrument, its corresponding virtual image also moves in real-time on the mobile 3D flat panel C-arm images.
By observing the screen of the surgical navigation system, the surgeon can grasp the relative position between the instrument and the patient’s anatomical structure at the surgical site in real-time. This information is crucial as it helps the surgeon accurately evaluate the distance between the surgical instrument and the target point, enabling precise surgical operations along the pre-planned surgical path.
Surgical Robot Planning
Combining mobile 3D flat panel C-arm imaging with surgical robot navigation significantly improves the success rate of pedicle screw placement, reduces the occurrence of complications in spinal surgery, and minimizes radiation exposure for both doctors and patients. Additionally, it effectively reduces intraoperative bleeding, postoperative pain, and shortens hospital stays, allowing patients to recover in a very short time.
