Combining Two Breast Cancer Diagnosis Technologies: Diffuse Optical Tomography with EIS

Abstract

Both Frequency-Domain Diffuse Optical Tomography (FD-DOT) and Electrical Impedance Spectroscopy (EIS) are mature and developed technologies that have been used separately for breast cancer detection. In this paper we have developed and present a handheld diffuse optical tomography probe combined with EIS to monitor, non-invasively, real time biological tissue activity in vivo. The proposed probe has two near-infrared wavelengths LEDS (capsulated in one package) and one photodiode, and two Ag/AgCl electrodes. Using FD-DOT with multispectral evaluation algorithm, we can measure Tissue Oxygenate Index (TOI), change of TOI, Tissue Oxygenate Hemoglobin (TOH) and Tissue Deoxygenate Hemoglobin (TDH) as well as determine the concentrations of water, lipids and optical scattering properties in normal and cancerous breast tissue. The EIS provides information regarding electrical properties of tissue specifically increased cellular water, sodium content, altered membrane permeability, and changed packing density and orientation of cells. The two point EIS is capable of a frequency sweep from 1 Hz to 50 MHz, but to overcome skin impedance and electrode polarization issues, the 100KHZ to 1MHZ frequency range has been considered for the present study. The combined FDOT-EIS system is used to provide simultaneous electrical as well as optical characteristics of in-vivo tissue.