Systems and methods for analysis and treatment of a body lumen

A system for analyzing a body lumen comprising:

• a catheter comprising a flexible conduit that is elongated along a longitudinal axis, the flexible conduit having a proximal end and a distal end;
• at least one delivery waveguide and at least one collection waveguide extending along the flexible conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide located along a distal portion of the conduit;
• a spectrometer connected to the at least one delivery waveguide and the at least one collection waveguide, the spectrometer configured to perform diffuse reflectance spectroscopy through blood, wherein the spectrometer emits at least one primary radiation signal of a wavelength of between about 750 and 2500 nm that is directed through the transmission output to a wall of the body lumen, and wherein the transmission input collects radiation directed from the body lumen wall;
• and
• a controller system comprising computer-readable memory programmed to store the signal measured by the spectrometer and to enable the controller to calculate a distance between the catheter and the wall of the body lumen based on a signal measured by the spectrometer of the at least one primary radiation signal that traveled through blood between the catheter and body lumen, the controller further programmed to store the calculated distance in the computer-readable memory.