Novel low-cost fiber-optic colorimetric instrument to rapidly screen pre-malignant esophageal tissue

A cost-efficient screening device is needed to detect patients who have Barrett's esophagus, a precursor to esophageal adenocarcinoma - the most rapidly increasing cancer in US. We have developed a prototype instrument based on colorimetric assessment of esophageal lumen. The system consists of a small diameter (5 mm) fiber-optic probe, interfacing electronics, a probe-head position sensor and a computer for display and analysis. The probe has a central (1 mm OD) plastic optical fiber through which white light (3200 K) is incident on the collapsed esophageal lumen via a conical mirror in the probe-head. A parabolic mirror in the probe-head focuses the reflected light onto thirty 250 pm plastic optical fibers arrayed circularly around the central transmit-fiber. The reflected light is applied to a linear 520 x 3 RGB photo-diode array (external to probe) to generate proportional electrical signals. A position sensor tracks probe-head location as it is retracted, allowing generation of a 2D colormap of esophageal lumen. A color change from white (normal) to red (pre-malignant) indicates Barrett's esophagus. The system performed accurately in tests using models of esophageal lumen which simulate patterns observed in Barrett's esophagus.