A
catheter enables real-time light measurements, for example, without limitation, diffuse reflectance,
fluorescence, etc., from
biological materials, such as tissue (including blood), while performing
RF ablation. The
catheter tip design isolates illumination and collection paths within the tip
electrode such that light for illuminating the tissue of interest (e.g., cardiac tissue or blood) is isolated within the tip
electrode from light that returns from the tissue to the
catheter tip, and vice versa. Such a design advantageously avoids saturation of the
optical detector, and ensures
diffusion of the illumination light within the medium of interest. The catheter has a catheter body and a tip
electrode with a shell wall and a hollow cavity. The shell wall has at least an illumination opening and a collection opening. The catheter further includes a first
fiber optic cable in communication with the illumination opening, and a second
fiber optic cable in communication with the hollow cavity, wherein light emitted from the first
fiber optic cable exits the tip electrode to reach tissue through the illumination opening in defining a first path and returns to the tip electrode from the tissue into the hollow cavity through the collection opening in defining a second path, the first and second paths being optically isolated from each other within the tip electrode. The invention also includes a method of making an
ablation electrode tip defining isolated optical paths with in the tip electrode for light exiting the tip electrode and light returning to the tip electrode.