Laser light generated by the Laser Module is delivered to a Laser Delivery Device (LDD) Assembly, that is comprised of three components: the Laser Catheter Assembly (LCA), the Optical Fiber Diffuser (OFD), and the Coolant Supply Set (CSS). The LCA and OFD transmit laser energy to the tissue situated at their distal regions, to achieve the desired effect of the intended use. The use of coolant provides cooling for the surfaces of the CSS in contact with both the tissue and the LCA. Technological Characteristics: • A transparent, dual lumen Laser Catheter Assembly (LCA) for percutaneous delivery of the optical fiber into, or adjacent to, the target tissue and to provide a means for actively cooling tissue immediately adjacent to the LCA. • A Coolant Supply Set (CSS) that provides the source of cooling liquid to the LCA. The tubing set is terminated in a standard spike and consists of a length of tubing to permit the placement of a peristaltic pump anywhere along its length and the coolant recovery bag for collecting the cooling liquid after a single transit of the LCA. • A glass/silica Optical Fiber Diffuser (OFD) assembly for delivering near infrared light to the target tissue. The optical fiber is terminated in an 18mm long diffuser that emits light radially from the fiber.