Figure 2(c) shows the keypoints on the two surgical instruments and the pixel position of our tracking points relative to the center of the FOV at each step. Notably, the weights of both surgical instruments in the FOV are the same. Figure 2(d) shows changes of the tracking error and relative position of the two surgical instruments, which is consistent with the performance when a single surgical instrument tracking taskis performed. The performance of tracking static surgical instruments proves the feasibility of our proposed data-driven control approach.
Experiments on tracking moving instruments
Firstly, we evaluate the proposed method with one moving surgical instrument. As shown in Figure 3(a), the scatters represent the relative position of the tracking points on the surgical instrument in the FOV of the continuum laparoscope. The number of color-bar means the density of the tracking points in the image plane. The higher the value, the more times the tracking point locates in the area with the movement of surgical instrument. It is seen that most of the tracking points locate near the center of the FOV. The distance between the tracking point and FOV center of the laparoscope is shown in Figure 3(b). The average distance while tracking a moving surgical instrument is approximately 45.77 pixels.