Blackrefractiveindexmatching liquid for optical CT scanning

1
Black refractive index matching liquid for
optical CT scanning Kevin Jordan Jerry Battista
DOSGEL 2008 Hersonissos, Crete, Greece
October 2, 2008
Schulich School of Medicine Dentistry
The University of Western Ontario
2
Why black?

• solve chemical problem once
• wavelength independent, use with any colour of
  optical scanner
• increase dynamic range
• reduce noise and CT artifacts

Why compensate for transmission?
Why correct signal drift?
3
Jordan
4
Jordan
5
Scanner
Gel type
6
1 Black wavelength independent
Jordan
7
2 Compensating transmission increase dynamic
range
100
0
Position (0.2 mm)
Jordan
8
3 Signal drift ( ideally light intensity changes
only)
Temperature dependence 0.01 nm/K reflection and
transmission opposite phases
Dosgel04
Jordan
9
3 Signal drift due to addition of dye
10
1 Equivalent sources of carbon black
nanoparticles
Carbon Black aqueous soap solution flame
soot Staedtler-Mars black ink
Jordan
11
3 Black liquid stability
Pro transmission 2/week Cons black
precipitate algae growth evident
Jordan
12
1 Carbon black nanoparticle solution
(Sigma-Aldrich)
Jordan
13
3 Transmission stability (Sigma-Aldrich)
Jordan
14

• Summary
• carbon black solution absorption spectra
• slowly changes with time
• smoothly increases to shorter wavelengths
• many potential surfactants
• optimum choice of antimicrobial still to be
  decided (suggest H2O2)
• Recommendations
• use ultrasound cleaner bath to disperse carbon
  black nanoparticles
• verify compatibility of surfactant and refractive
  index matching liquid
• (for example glycerine is a co-surfactant)
• choose nontoxic biodegradable (green) chemicals

Jordan