Graduate Exam Abstract
December 14, 2011, 2pm
SINGLE CANCER CELL DETECTION WITH OPTOFLUIDIC INTRACAVITY SPECTROSCOPY
Abstract: The detection of cancer cells is the basis for cancer diagnostics, cancer
screening and cancer treatment monitoring. Non-destructive and
non-chemical optical methods may help reduce the complexity and cost of
testing for cancer cells, and thus make cancer diagnostics more available
to the public.
The label-free technique of optofluidic intracavity spectroscopy (OFIS)
uses light transmitted through a cellular body in a microfluidic optical
resonator to distinguish different types of cells by their spectral
The OFIS chips are fabricated in the CSU semiconductor clean room, and the
fabrication process has been modified to combine dielectrophoresis (DEP)
with the OFIS technique. Viability tests were carried out to investigate
the effect of heating (induced by DEP electrodes) on cells in chips built
with borosilicate and sapphire substrates.
Using OFIS chips fabricated with the modified process, OFIS spectra of
settled cells from canine hemangiosarcoma (HSA) cell lines and monocytes
in peripheral blood mononuclear cells (PBMCs) were collected and analyzed.
A single characteristic parameter method was developed to classify whether
or not a cell is cancerous. This method had high statistically
significance, with a p-value as low as 10^-6. A receiver operating
characteristic (ROC) curve constructed from t-distributions fit to the HSA
and monocytes spectra single parameter distribution indicated that cell
classification of the HSA and monocyte populations can achieve 95%
sensitivity and 98% specificity simultaneously.
Furthermore, some features observed in the spectra of HSA cells motivated
new optical models of the cell loaded F-P cavity. Firstly a thin lens
model allowed the extraction of cells focal lengths from OFIS spectra.
And statistical analysis revealed that focal lengths could be used as a
cell malignancy indicator. Furthermore, a thick lens model was developed,
allowing extraction of more optical parameters related to cell morphology
and cell location in the cavity. This model was used to interpret
experimental results acquired from settled and suspended cells.
Adviser: Dr. Kevin Lear
Non-ECE Member: Dr. Kenneth Reardon, CBE
Member 3: Dr. Diego Krapf, ECE
Addional Members: Dr. V Chandrasekar, ECE
i. H. Shao, W. Wang, S. E. Lana, and K.L. Lear, "Optofluidic intracavity spectroscopy of canine lymphoma and lymphocytes," IEEE Photonics Technology Letters, vol. 20, no. 5-8, pp. 493-495, Mar-Apr, 2008.
ii. W. Wang, and K. L. Lear, "A cell lens model for transverse modes in optofluidic intracavity spectroscopy," Journal of Selected Topics in Quantum Electronics on Biophotonics, vol. 16, no. 4, pp. 946-953, Jul-Aug, 2010.
iii. W. Wang, D.W. Kisker D.H. Thamm, H. Shao, and K. L. Lear, "Optofluidic Intracavity Spectroscopy of Canine Hemangiosarcoma," IEEE Transactions on Biomedical Engineering, vol. 58, no. 4, pp. 853 - 860, April, 2011.
Program of Study: