Development of a synchronous motion-tracking and video capture tool for flexible ureteroscopy

Hand/instrument motion-tracking in surgical simulation provides valuable data to improve psychomotor skills and can serve as a formative evaluation tool. Motion analysis has been well-studied in laparoscopic surgery; however, there are essentially no studies looking at motion-tracking for flexible ureteroscopy (fURS ), a common surgical procedure requiring hand dexterity and 3D spatial awareness. We aimed to design a synchronized motion-tracking and video capture system for fURS capable of collecting objective metrics for use in surgical skills training.

Motion tracking of the ureteroscope was performed using a motion-tracking platform, inertial measurement units (IMUs), and an optical sensor. Position (x, y, z) and orientation (roll, pitch, yaw) of the ureteroscope handle, lever deflection, and translation of the scope insertion point were collected. Video capture of the operator's hands was collected with a Raspberry Pi camera. All peripherals were controlled on a Raspberry Pi 4 and synchronized to its system clock.

Our system demonstrated good accuracy in detecting translation of the ureteroscope in the x- and y-axes, and yaw, pitch and roll of the ureteroscope at discrete orientations of 0, ±30, ±60, and ±90 degrees. Unique to fURS, deflection of the lever was captured by the difference in IMU static accelerations with good accuracy. The optical sensor detected translation of the ureteroscope at the insertion point with good precision and an average error of 5.51%.

We successfully developed a motion-tracking and video-capture system capable of collecting motion-analysis parameters unique to fURS . Future studies will focus on establishing the construct validity of this tool.