Graduate Exam Abstract

Weina Wang

Ph.D. Final
December 14, 2011, 2pm
Engineering E103

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 signature. 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
Co-Adviser: N/A
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: