A portable, low coherence interferometry based instrument for fine needle aspiration biopsy guidance

Abstract

A portable, low coherence interferometry (LCI) based instrument for fine-needle aspiration biopsy guidance is presented. The instrument consists of a fiber-based low coherence interferometer, a data acquisition, processing and display unit, and a probe. The probe, consisting of a 250μm diameter single-mode optical fiber inserted within the bore of a fine needle, is used to illuminate tissue and collect light from tissue at the tip of the needle. Light returning out of the probe is detected by the LCI system, which is capable of measuring depth-resolved information (reflectivity, spectra, birefringence) with a spatial resolution of 10μm over a depth range of approximately 1.4mm. The LCI based instrument can be used to guide the fine needle during biopsy procedures to potentially diagnose neoplasms, infections, inflammations, or infiltrations. The design and performance of the instrument, as well as preliminary measurements on excised breast tissue specimens, are presented in detail.