Design of an Endoscopic Design of an Endoscopic Raman Probe for Detection of Raman Probe for Detection of

Ovarian CancerOvarian Cancer

Elizabeth Kanter

Matt Keller

Vanderbilt University

Advisor: Dr. Anita Mahadevan-Jansen

VU BME

GoalsGoals

Gain comprehensive understanding of Raman spectroscopy and basic understanding of ovarian physiology

Research design limitations imposed by laparoscope and physiological environment

Come up with innovative probe design to allow detection of ovarian cancer

Implement design for clinical use

Raman ScatteringRaman Scattering

Photons collide inelastically with scattering molecule

Molecule enters virtual excited vibrational state, then returns to lower state

Photon of lower frequency re-emitted

Raman SpectrumRaman Spectrum

Plot of signal intensity vs. shift in wavenumberVery weak signal, compared to fluorescencePeaks narrow and highly specific to particular

bonds (diff between normal & cancerous tissue)

0

5

10

15

20

25

30

35

600 800 1000 1200 1400 1600 1800Raman Shift (cm-1)

Inte

nsi

ty

Processed Raman spectrum

Fluorescence background

Measured Glucose spectrum

X 3

Ovarian CancerOvarian CancerLifetime odds of developing are 1/70Family history biggest risk factor: 3.6 times

more likely to develop ovarian cancer if have primary relative afflicted

Asymptomatic until final stages, so need reliable, minimally invasive early detection method for women at risk

Current detection methods (pelvic & rectal exam, ultrasonography, biopsy) either not reliable for early detection or too invasive

Benefits & Problems of Our Benefits & Problems of Our SystemSystem

Minimally invasiveOne-time cost for clinicsReliable early detection

Must remain flexible and fit in laparoscopic tubing (< 5 mm)

Must be able to visualize location of probeMust read only the Raman signal

Current Probe DesignsCurrent Probe Designs

Current Probe DesignsCurrent Probe Designs

Central fiber-laser fiber Surrounding fibers-

collection fiber Each fiber has a filter on

the bottom, either notch or band pass

Current WorkCurrent Work

Finding availability of micro-optical parts needed– Band-pass filters, notch filters, fiber coatings

Discussing laparoscopic developments with gynecologists

Future WorkFuture Work

Build large-scale models to test design

Scale down best design to fit in laparoscope

Clinical trials

ReferencesReferences

Frank, C.J., Redd, D. C., Gansler, T.S, McCreedy, R.L. “Characterization of Human Breast Biopsy Specimens with Near- IR Raman Spectroscopy” Analytical Chemistry, 66, 319-326 (1994)

Mahadevan-Jansen, A., Raman Spectroscopy: From Bench top to Bedside. (2002)

National Cancer Institute