Respect for Tissue Representation Using Photoelastic Stress Analysis for Endovascular Surgery Simulation - Microsurgery: Advances, Simulations, and Applications - page 152

the guide wire is considered bent if there are more pixels per column
than the guide wire diameter size. This can be used to lip the search
direction when the bent condition is detected [10].

4 2

(x+1, y+2) (x+2, y+2)

Actual
Pixel
(x, y)

1

(x+2, y)

3

5

(x+2, y-2)

(x+1, y-2)

Figure 4.26 Search priorities for catheter tip location inside the image.

Top Front

Tip

Tip

X X

Y Z

Catheter

S1-S2
(mmHg)

0 640 1280 1920 2560

Figure 4.27 An example of result images after applying the iltering,
measurement and search algorithm described in this section
to the photoelastic images. The frame rate of the real-time
analysis using the bi-planar vision system is above 3 fps.

4.11.5 Reference Trajectory Construction

The image-processing software described in the previous section
was used for and stress analysis, morphology extraction, catheter