Ablation catheters and systems include coaxial catheter shafts with an inner lumen for delivering an ablative agent and an outer lumen for circulation of a cooling element about the catheter. Induction heating is used to heat a chamber and vaporize a fluid within by wrapping a coil about a ferromagnetic chamber and providing an alternating current to the coil. A magnetic field is created in the area surrounding the chamber which induces electric current flow in the chamber, heating the chamber and vaporizing the fluid inside. Positioning elements help maintain the device in the proper position with respect to the target tissue and also prevent the passage of ablative agent to normal tissues.

A phototherapy apparatus includes a light generator configured to generate a laser beam; an optical fiber coupled to the light generator and including a light transfer portion configured to transfer the laser beam and a light scattering portion configured to output the laser beam in a radial direction; a first tube into which the optical fiber is inserted, and configured to inject fluid into one end; a second tube into which the first tube is inserted, and configured to discharge the fluid in a region with an outer surface of the first tube; a guide portion configured to accommodate the optical fiber by forward movement of the optical fiber and disposed on the same axis as the first tube; and a balloon configured to surround one ends of the first tube and the second tube and the guide portion and to expand and reduce according to injection and discharge of the fluid.

Apparatus and methods are described for treating an occlusion in a blood vessel. A catheter is inserted into the blood vessel. An irradiation unit is driven to emit probing radiation such that the probing radiation is directed toward the occlusion, and returning radiation which is returned in response to the probing radiation impacting the occlusion, is detected. A composition of at least a portion of the occlusion is derived based on a signature that is indicative of the composition within the returning radiation. The irradiation unit is driven to irradiate the portion of the occlusion by emitting treatment radiation having a set of irradiation parameters. The set of irradiation parameters is determined to modulate between a photoacoustic effect of the treatment radiation and a photothermal effect of the treatment radiation, based on the composition of the portion of the occlusion. Other applications are also described.

Ablation catheters and systems include coaxial catheter shafts with an inner lumen for delivering an ablative agent and an outer lumen for circulation of a cooling element about the catheter. Induction heating is used to heat a chamber and vaporize a fluid within by wrapping a coil about a ferromagnetic chamber and providing an alternating current to the coil. A magnetic field is created in the area surrounding the chamber which induces electric current flow in the chamber, heating the chamber and vaporizing the fluid inside. Positioning elements help maintain the device in the proper position with respect to the target tissue and also prevent the passage of ablative agent to normal tissues.