Fiber Optic Sensor Prototype for Breast Cancer Imaging

Abstract

Breast cancer is the most common type of cancer and the second most common cause of death by cancer for women. Early diagnosis of a malignant tumor in the breast can dramatically increase survivability. Therefore, the clarity and accuracy of a detection scheme is crucial to improve the survival rate of breast cancer. Near-Infrared Diffuse Optical Imaging and Spectroscopy (NIR-DOIS) is an imaging methodology under development which has the potential to clearly and accurately assess the malignancy of a suspicious lesion. Tumor malignancy corresponds to certain physiological parameters, namely oxygen saturation and hemoglobin concentration. NIR-DOIS is capable of measuring these parameters, providing a functional measurement of multiple physiological parameters with potential molecular sensitivity. When compared with other imaging modalities, NIR-DOIS has the advantage of being a low cost, non-invasive, real-time diagnostic. This imaging technique can be accomplished using fiber optic cables which are arrayed in a hand-held sensor head that is placed against the skin of the patient. The near-infrared light shines from the source fiber into the tissue and the reflected light is collected by the detector fibers. Source and detector fibers are connected to a tissue oximetry device that synchronizes the light illumination and the data collection, allowing it to interpret physiological parameters such as oxygen saturation and hemoglobin concentration from optical measurements. In order to reconstruct the embedded tissue heterogeneities such as breast tumors, it is necessary to collect multiple data sets with a matrix of sources and detectors. However, the fact that the existing tissue oximetry system has limited sources and detectors prevents the reconstruction of the tissue heterogeneities with high accuracy. In order to improve the imaging capability of the existing tissue oximetry system, it is necessary to develop an imaging head with a condensed distribution of source and detector channels, and an optical switching unit that can rapidly sweep through all these source and detector channels. The hypothesis of this project is that the optical switch will be an effective means to accurately detect oximetry data using NIR-DOIS. The research project includes completing a prototype optical switch, programming the necessary motor control functions to integrate the switch with a computer, and testing the device to determine baseline performance and potential clinical efficacy. Performance testing will be done using a laser and a light detector in order to determine light transmission through the optical switch, first through the fibers alone and then through the switch.