Light delivery catheter

Abstract

A light delivery catheter having an elongate, flexible inner tube coaxially disposed within a lumen within a flexible outer tube, and axially movable with respect to the outer tube. An optical waveguide disposed within the inner tube conducts light from an external light source to a light diffuser element in optical communication with the distal end of the optical waveguide. A portion of the light conducted to the diffuser element is scattered radially into the surrounding volume. The outer diameter of the inner tube is less than the diameter of the outer tube lumen, the annular space therebetween forming a cylindrical lumen coextensive with the inner tube. One or more fiber optics disposed within the cylindrical lumen are attached to the outer surface of the inner tube and terminate distally in an isotropic tip. Fiber optic bending means, responsive to advancement of the inner tube within the outer tube, causes the distal tips of the fiber optics to bend radially outward, as the distal tip of the inner tube emerges from the confines of the outer tube lumen. In operation, the distal tip of the outer tube is positioned within a body cavity. The inner tube is advanced through the outer tube lumen until the element and the distal tips of the fiber optics project beyond distal end of the outer tube. Therapeutic light from an external source is conducted from the proximal end of the optical waveguide to the diffuser element. The diffuser element scatters a portion the light radially, a portion of the radially scattered light being picked up by the fiber optic tips which are in contact with the tissue on the inner surface of the body cavity. The portion of light entering the isotropic tips is conducted to the proximal end of the catheter via the respective fiber optics for light detection and measurement.