Fluorescence sensing of tissue

A method of medical diagnosis, the steps comprising:

• inserting a distal end of a catheter into a patient, the catheter also having a proximal end and including an outer hood having a first opening disposed therein, an inner hood within the outer hood, an optical fiber having a tip within an interior of the inner hood and a lens at the tip;
• outputting a diagnostic laser beam from the optical fiber, through the lens within the outer hood to pass through the opening and be applied to tissue of the patient;
• sensing fluorescent light passing through the lens from the laser stimulation of the tissue;
• and
• supplying clear solution to the opening such that the diagnostic laser beam and the fluorescent light have relatively clear paths;
• and wherein the fluorescent light that is sensed passes through the opening along the relatively clear path established by the supplying of clear solution.

A method of medical diagnosis, the steps comprising:

• inserting a distal end of a catheter into a patient, the catheter also having a proximal end;
• outputting a diagnostic laser beam from a lens at the distal end of the catheter and applying the diagnostic laser beam to tissue of the patient;
• sensing fluorescent light from the laser stimulation of the tissue;
• and
• wherein the catheter includes an optical fiber extending from the distal end to the proximal end and the step of outputting the diagnostic laser beam results from application of laser energy to the proximal end of the optical fiber;
• and wherein the sensing of fluorescent light from the laser stimulation of the tissue is accomplished by having fluorescent light pass along the optical fiber from the distal end to the proximal end, after passage through the lens at the distal end, and enter a detection subsystem at the proximal end, the optical fiber thus passing fluorescent light in one direction and passing laser energy for the diagnostic laser beam in a direction opposite to said one direction.