Abstract: A method of delivering light energy to target matter in a mammalian body is described. The method may include inserting at least a portion of a catheter into a patient's vasculature, wherein the catheter comprises an open distal tip, a lumen extending proximally from the open distal tip, and at least one optical fiber within the lumen, wherein the at least one optical fiber has a distal end. The method may include flowing a liquid light guide medium through the open-ended catheter tip, wherein the liquid light guide medium flows beyond the distal end of the at least one optical fiber, wherein the liquid light guide medium comprises a magnesium chloride solution having an ion concentration that is isotonic with blood and tissue. The method may include forming a fluid optical channel with the liquid light guide medium between the catheter and the target matter. Other methods are described.

Abstract: A catheter system to ablate target matter within a mammalian body using light energy is described. The system may include an open-ended catheter tip through which a liquid light guide medium flows to the target matter, where at least a portion of the liquid light guide medium exiting the catheter tip creates a fluid optical channel to transmit the light energy from the catheter tip to the target matter. The system may also include a catheter lumen whose distal end includes the open-ended catheter tip, a light source to generate the light energy, and a liquid light guide medium source fluidly coupled to the catheter lumen. The liquid light guide medium source may include a reservoir of the liquid light guide medium that includes a magnesium chloride solution or a lactated Ringer's solution.

Abstract: A method of delivering light energy to target matter in a mammalian body is described. The method may include inserting at least a portion of a catheter into a patient's vasculature, wherein the catheter comprises an open distal tip, a lumen extending proximally from the open distal tip, and at least one optical fiber within the lumen, wherein the at least one optical fiber has a distal end. The method may include flowing a liquid light guide medium through the open-ended catheter tip, wherein the liquid light guide medium flows beyond the distal end of the at least one optical fiber, wherein the liquid light guide medium comprises a magnesium chloride solution having an ion concentration that is isotonic with blood and tissue. The method may include forming a fluid optical channel with the liquid light guide medium between the catheter and the target matter. Other methods are described.

Abstract: A catheter system to ablate target matter within a mammalian body using light energy is described. The system may include an open-ended catheter tip through which a liquid light guide medium flows to the target matter, where at least a portion of the liquid light guide medium exiting the catheter tip creates a fluid optical channel to transmit the light energy from the catheter tip to the target matter. The system may also include a catheter lumen whose distal end includes the open-ended catheter tip, a light source to generate the light energy, and a liquid light guide medium source fluidly coupled to the catheter lumen. The liquid light guide medium source may include a reservoir of the liquid light guide medium that includes a magnesium chloride solution or a lactated Ringer's solution.