Respect for Tissue Representation Using Photoelastic Stress Analysis for Endovascular Surgery Simulation - Microsurgery: Advances, Simulations, and Applications - page 135

2 Q
M

I GN

sin

Re (4.25)

G

The green light intensity was measured for each region of the
variable retardation device and normalized using equation (4.21).
As the value of Re is known for each region, the value of M G may be
calculated from equation (4.23).The normalized values of green
were plotted against their corresponding retardation in Fig. 4.9. The
value of

M G is obtained by minimizing the error between the plot and
the mathematic model of equation (4.25). The error minimizes when
M G = 510.
The quarter-wave plates are provided with a precision of 10 nm;
therefore, they may add in some cases a maximum error of 14.5% to
the model proposed in equation (4.24). This error may be suppressed
by coniguring the camera to capture M G = . M ex .

Wave Plates Reference
Mathematic Model

1

0.8

0.6

0.4

0.2

0

100 200 300 400 500 600

Retardation (nm)

Figure 4.9 Plot of the retardation introduced by the quarter plates in
the studied areas, and their respective normalized green light
intensity. The mathematical model proposed by equation
(4.25) with

M G = 510 nm is also shown.

4.6 Photoelastic Coefficient of Urethane

Elastomer

In this study, we used NIPOLAN5120 urethane elastomer-dyed
yellow with I-01-001Y of Epoch Co. at 0.1w% for manufacturing