Methods Figures
Figure 1. The bactericidal efficiency of UV light
against E. coli as a function of the wavelength of
light. (Wang et.al. Pulsed Ultra- Violet Inactivation
Spectrum of Escherichia coli. Water Research.
39:2921-2925. 2005)
Figure 2. The UV light dose required to eliminate
bacteria as a function of the wavelength of the light.
(Wang et.al. Pulsed Ultra- Violet Inactivation
Spectrum of Escherichia coli. Water Research.
39:2921-2925. 2005)
Figure 3. Above is a display of the cross-section
of a hollow waveguide. Number 1 indicates the
hollow waveguide. Number 2 indicates the glass
tube base of the waveguide. Number 3 indicates
the aluminum film. Number 4 is the hollow core of
the waveguide.
Figure 4. The above graph displays the amount of
light loss that occurs at different curvatures for a 1 m
long fiber of different diameters (0.32 mm, 0.70 mm,
and 1.00 mm) being coupled using an ArF-excimer
laser (17).
Figure 5. The ball lens on the UV LED begins the
process of focusing the light by achieving a 1.5mm
spot diameter. <http://www.s-et.com/ >
Figure ?. The UV LED and hollow waveguide coupled system used to
measure both intensity and bactericidal properties of the 270 nm, UV light.
Figure ?. The 1 μL spot of Staphylococcus
aureus bacteria was exposed using an
inverted setup of the LED and waveguide
aimed directly at the colony with the end of
the hollow waveguide a distance of 3 mm
from the colony.
Results Figures
Power Required (μW)
25000
20000
15000
10000
5000
0
3
4
5
6
7
8
Endotracheal Tube Diameter (mm)
Figure 6. The amount of power required to eliminate
99% of bacteria (blue), 75% of bacteria (red), and 50%
of bacteria (green) as a function of the diameter of the
endotracheal tube increases as the tube diameter and
surface area increase.
Total Irradiation Time Required
with Laser (s)
8
7
6
5
4
3
2
1
0
3
4
5
6
7
Total Irradiation Time Required
with UV LED (s)
ETT Inner Diameter (mm)
25000
20000
15000
10000
5000
0
3
4
5
6
7
ETT Inner Diameter (mm)
Figure 7. The amount of irradiation time necessary to
eliminate 99% of the bacteria present in the ETT as a
function of the ETT inner diameter is shown as a
comparison between the example UV laser and the UV
LED.
Control
Test
Figure ?. The bacterial colonies of the
control (left) and the UV exposed bacteria
(right) are circled in white and do not have
visible differences.