Detection system, catheter device, and laser ablation device
A detection system includes: at least one light source that outputs a plurality of test beams input to a proximal end portion side of an optical fiber and having different wavelengths and providing different bending losses of the optical fiber; at least one reflector that reflects each of the test beams propagating through the optical fiber, on a distal end portion side of the optical fiber; a plurality of light receiving units that receive a plurality of reflected beams each being a beam reflected by the at least one reflector, on the proximal end portion side; and a determination unit that, based on information about the reflected beams at the plurality of light receiving units, compares the information about the reflected beams with reference set values.
1. A laser ablation device for outputting an ablation laser beam from a distal end of an optical fiber and irradiating a target area with the ablation laser for treatment, comprising:
a laser beam source that outputs the ablation laser beam input to a proximal end portion side of the optical fiber;
at least one light source that outputs a plurality of test beams input to the proximal end portion side of an optical fiber and having different wavelengths and providing different bending losses of the optical fiber;
at least one reflector that reflects each of the test beams propagating through the optical fiber, on a distal end portion side of the optical fiber;
a plurality of light receivers arranged to receive a plurality of reflected beams each being a beam reflected by the at least one reflector, on the proximal end portion side;
a first optical multiplexer/demultiplexer configured to multiplex the plurality of test beams;
a second optical multiplexer/demultiplexer configured to demultiplex the plurality of reflected beams; and
a determination unit comprising a calculation unit and storage unit which are configured so that the determination unit, based on information about the reflected beams at the plurality of light receivers, compares the information about the reflected beams with reference set values,
wherein the information about the reflected beams includes received light intensities of the reflected beams at the light receivers, and the reference set values are thresholds of the received light intensities, and
the determination unit is configured so that it determines whether the optical fiber is bent or broken based on the received light intensities of the reflected beams.
2. The device according to claim 1 , wherein the determination unit is configured so that it:
determines that the optical fiber is broken, when a received light intensity of a first reflected beam, of the plurality of reflected beams, is not more than a first threshold, the first reflected beam being a reflected beam from a first test beam;
determines that the optical fiber is not broken, when the received light intensity of the first reflected beam is larger than the first threshold; and
determines that the optical fiber is bent with an amount of bending not less than a predetermined amount of bending, when the received light intensity of the first reflected beam is larger than the first threshold and a received light intensity of a second reflected beam, of the plurality of reflected beams, is not more than a second threshold, the second reflected beam being a reflected beam from a second test beam provides a larger bending loss in the optical fiber than the first test beam does.
3. The device according to claim 1 , wherein when a received light intensity of a second reflected beam of the plurality of reflected beams has rapidly decreased, the second reflected beam being a reflected beam from a second test beam, the determination unit is configured so that it:
determines that the optical fiber is broken, when a received light intensity of a first reflected beam is not more than a first threshold, the first reflected beam being a reflected beam from a first test beam provides a smaller bending loss in the optical fiber than the second test beam does; and
determines that the optical fiber is bent, when the received light intensity of the first reflected beam is larger than the first threshold.
4. The device according to claim 3 , wherein when the received light intensity of the second reflected beam has rapidly decreased, information about an amount of bending is obtained from a state of decrease in the second reflected beam, when the received light intensity of the first reflected beam is larger than the first threshold.
5. The device according to claim 1 , comprising a plurality of the reflectors, at least one of which includes a fiber Bragg grating.
6. The device according to claim 1 , comprising a plurality of the reflectors, at least one of which includes a reflecting film.
7. The device according to claim 1 , wherein
at least one of the plurality of light receivers is a photodiode.
8. A catheter device comprising:
the laser ablation device according to claim 1 ;
the optical fiber to which the plurality of test beams are input from the proximal end portion side, and in which the at least one reflector is provided on the distal end portion side; and
a catheter body into which at least a part of the optical fiber is inserted.
9. The laser ablation device of claim 1 , wherein the determination unit is further configured to detect a degree of bending of the optical fiber based on the information about the reflected beams at the plurality of light receivers.
10. The laser ablation device of claim 1 , wherein the at least one light source simultaneously outputs a plurality of test beams input to the proximal end portion side of an optical fiber and having different wavelengths and providing different bending losses of the optical fiber.
11. The laser ablation device of claim 10 , further comprising a multiplexer configured to multiplex the plurality of test beams with the ablation laser beam.