JPH11332876A - Laser light irradiator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser light irradiator which irradiates a laser light to the side from the front of an insulating part to perform a scanning. SOLUTION: In a laser light irradiator 1 which has an optical fiber 3 for guiding a laser light into a catheter 2 and a laser light reflection means provided near the tip of the catheter 2, the laser reflection means is provided with a cantilever 5 and a reflection surface 6 both produced by forming a shape memory material into a flat plate and has a lead 7 and a heater 8 as heating means for heating the cantilever 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam irradiating apparatus for irradiating a laser beam from a distal end of a main body such as a catheter which can be inserted into a body cavity, and more particularly, to a laser ablation treatment and an examination. The present invention relates to a laser beam irradiation device.

[0002]

2. Description of the Related Art Conventionally, various devices have been developed for the purpose of cauterizing and treating lesions such as cancers and tumors generated inside a body cavity. Among them, for example, JP-A-4-285550 and JP-A-5-285550
Japanese Patent Application No. 237132 discloses a method of changing the irradiation direction of laser light using a shape memory material.

In these devices, an optical fiber for guiding a laser beam is bent by, for example, a deformation force of a shape memory alloy,
By changing the direction of the tip (emission end), laser light is emitted in a target direction. The use of these devices makes it possible to control the direction of the laser light emitting end of the optical fiber, and to irradiate a predetermined portion with the laser light.

[0004]

In these conventional apparatuses, the optical fiber itself is bent in order to change the direction of laser beam irradiation. However, the optical fiber cannot be bent smaller than the minimum radius of curvature, and the angle of curvature is greatly limited in a body cavity, particularly in a narrow space such as a blood vessel, so that the laser beam is directed laterally in the insertion axis direction. Was difficult to use.

[0005] In the present invention, the irradiation of the laser beam to the front and side of the insertion portion can be switched, and the irradiation can be performed on the inner wall of the luminal tissue around the insertion portion even in a narrow space such as a luminal organ or a blood vessel. It is an object of the present invention to provide a simple laser light irradiation device.

Further, in the present invention, it is possible to irradiate and scan the laser beam from the front to the side of the insertion portion, and to make the mechanism for irradiating and scanning the laser beam into the body cavity simple and small. It is an object of the present invention to provide a laser beam irradiation device which is light in burden on a patient and highly reliable.

[0007]

This and other objects are attained by the following inventions (1) to (6).

(1) A laser beam irradiating apparatus having a long insertion section, light guide means for guiding laser light into the insertion section, and laser light reflection means provided near the tip of the insertion section. The laser beam reflecting means is a cantilever in which a substance having a shape memory effect is formed in a plate shape.
A laser beam irradiation device comprising: a cantilever beam; a reflecting surface; and heating means for heating the cantilever.

(2) The laser beam irradiation apparatus according to the above (1), wherein the cantilever is an omnidirectional shape memory material.

(3) The laser beam irradiation apparatus according to the above (1), wherein the cantilever is a bidirectional shape memory material.

(4) The cantilever is a one-way shape memory material, and the laser beam reflecting means further includes a bias spring material for applying a force to bend the cantilever. The laser light irradiation device according to claim 1.

(5) The laser beam irradiation apparatus according to the above (1), wherein the heating means is formed by laminating a flat heater means on the cantilever.

(6) The laser beam irradiation apparatus according to the above (1), further comprising cooling means for supplying and discharging a cooling fluid around the cantilever.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a laser beam irradiation apparatus according to the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

FIGS. 1 and 2 are views for explaining the configuration of the tip of a laser beam irradiation apparatus according to the present invention. FIG. 1 shows a state in which a laser beam is irradiated laterally. FIG.
Indicates a state of irradiating forward. FIG. 3 is a front view of the state of FIG. 2 and a sectional view taken along line AA, and FIG. 4 is a front view of the state of FIG. 1 and a sectional view taken along line BB of FIG.

In FIG. 1 to FIG. 4, a laser beam irradiation device 1 has a catheter 2 inserted into a body cavity.
An optical fiber 3 for guiding laser light generated from a laser light source (not shown) connected to the base end of the laser light irradiation device 1 is inserted, and an acrylic resin or quartz is inserted into the distal end of the catheter 2 so that the laser light is transmitted. A tip cap 4 made of a light-transmitting material such as the above is attached.

The cantilever 5 is an actuator made of an omnidirectional shape memory material, and a reflection surface 6 is provided on the surface of the cantilever 5 to which the laser light is irradiated so that the laser light can be efficiently reflected. Further, as a heating means, a lead wire 7 for current supply and a heater 8 connected to the lead wire 7 are provided. The heater 8 is formed in a flat plate shape,
It is provided to be laminated on the cantilever 5.

A collimating lens 9 is provided at the laser beam emitting end of the optical fiber 3. In a normal optical fiber, the emitted laser light spreads at an opening angle (around 40 degrees) determined by the refractive index of the core of the optical fiber. In this case, not only a small portion of the emitted laser light reaches the reflection surface, but also the profile of the laser light after reflection is significantly reduced. The collimating lens 9 suppresses the diffusion of laser light as much as possible and emits convergent light.

The diameter of the exit end of the optical fiber 3 with the collimating lens 9 attached is 1.5 mm, and the size of the reflecting surface 6 provided on the cantilever 5 is 1 mm × 1 m.
m, and these are catheters 2 having an outer diameter (diameter) of 3 mm.
It is built in.

The catheter 2 is formed so as to have a gap around the optical fiber 3, and the surrounding gap can function as an air supply lumen 10a and an exhaust lumen 10b. A partition wall 11 is formed in the inner hole of the catheter 2, and the partition wall 11 separates the air supply lumen 10 a and the exhaust lumen 10 b while fixing the optical fiber 3 and the lens 9. I do. Through these lumens 10a and 10b, carbon dioxide gas is circulated as a cooling fluid from a cooling fluid circulating device (not shown) from the proximal end of the catheter 2. The carbon dioxide gas used for cooling the device only flows through the inside of the catheter 2 and does not leak out of the catheter 2.

The heater 8 is made of flattened platinum,
It is formed in a laminated structure with a cantilever 5 made of a shape memory material. By passing an electric current through the lead wire 7 that has passed through the inside of the catheter 2, a heat quantity necessary for deformation of the shape memory material is obtained.

When the cantilever 5 is not energized to the heater 8 (no heating), the cantilever 5 extends straight as shown in FIG. 2 and FIG. The reflecting surface 6 is completely deviated from the irradiation range of the laser beam, and in this state, the laser beam is irradiated in the direction of the tip in the catheter axial direction (forward).

When an electric current is applied to the heater 8 and heat is applied to the shape memory material to gradually increase the temperature, the cantilever 5 moves at about 45 degrees with respect to the optical axis of the laser beam as shown in FIGS. It becomes a shape that intersects. In this embodiment, the temperature at this time is about 80 degrees, but since the heating is very local near the cantilever 5, the outside of the catheter 2 is not heated. At this time, a state in which the exit end of the optical fiber 3 is viewed from the distal end direction of the catheter 2 is illustrated. As shown in FIG. 4, the exit end of the optical fiber 3 is hidden behind the reflection surface 6 of the cantilever 5. Becomes The laser light is reflected by the reflecting surface 6 and consequently from the axis of the catheter 2
Irradiates 90 degrees to the side.

In this embodiment, since the omnidirectional shape memory material is used as the shape memory material, the cantilever 5 is moved between the state shown in FIG. 1 and the state shown in FIG. 2 according to the temperature by heating and the shape stored in advance. Any angle between can be taken. At this time, the laser light is emitted in an arbitrary direction between the front and the side in the axial direction of the catheter 2.

When the power supply to the heater 8 is stopped and the heating is stopped, the shape memory material is rapidly cooled by the flow of the carbon dioxide gas ventilated through the lumen of the catheter 2, and the shape memory material is accordingly cooled. It returns to its normal temperature (straight state). This ventilation cooling allows the cantilever 5
Can be rapidly reduced, so that the cantilever 5 can be quickly returned to the normal temperature angle as compared with the time of natural cooling, and the scanning speed of the laser beam can be improved.

Here, the laser beam emitted from the catheter 2 to the outside can be scanned by repeating the energization of the heater 8 intermittently. When it is desired to fix the irradiation in a certain direction, the amount of current may be adjusted so that the temperature of the shape memory material becomes constant.

In this embodiment, an omnidirectional shape memory material is used as the shape memory material, but a bidirectional shape memory material may be used. For bidirectional shape memory materials, the angle that cantilever can hold is limited to two specific angles (usually a straight state and a state of 45 degrees to laser light), and it can hold any angle between them Other than that, it can be used for laser beam irradiation by the same mechanism.

Further, a one-way shape memory material may be used as the shape memory material, and a bias spring material for applying a force for bending the shape memory material may be laminated on the cantilever and a combined structure may be used. With this configuration, the angle of the cantilever obtained by bending the cantilever by the bias spring and the angle of the cantilever stored in the shape memory material when heated by the heating unit are obtained.
The angle at which the laser beam enters the reflecting surface on the cantilever changes depending on the degree of heating,
Laser light can be irradiated in two directions.

As the shape memory material used for the cantilever 5, a shape memory resin or a shape memory alloy is preferably used, and specifically, a shape memory material such as a polyurethane polymer, a polyisoprene polymer, and a polysorbone polymer. A resin or a shape memory alloy such as a NiTi alloy, a Cu-Zn-Al alloy, or a Cu-Al-Ni alloy is preferable. The transformation point of these shape memory materials is 40 to 8 degrees.
It is preferable that the angle is about 0 degrees. The transformation temperature should be selected so that heat does not leak out of the catheter 2 and there is no risk of deformation during non-heating.

The reflecting surface 6 can be obtained by forming a metal thin film on the surface of the cantilever 5.
Specifically, by depositing a metal such as Al, Ti, and Pt, a reflective surface having a high reflectance can be suitably obtained.

The embodiments of the present invention described above are described to facilitate understanding of the present invention, and the present invention is not limited to the embodiments. Therefore, each element disclosed in the above embodiments includes all design changes and equivalents belonging to the technical scope of the present invention.

For example, in this embodiment, the case where the laser beam irradiation apparatus according to the present invention is used in the case of laser ablation treatment or inspection using a catheter has been described. It may be applied to the use in the.

[0033]

As described above, according to the present invention, the scanning of the lesion with the laser beam is realized by changing the angle of the cantilever driven by the shape memory material.
It is possible to irradiate a predetermined range with laser light without moving the main body of the catheter inserted into the body cavity. That is, laser beam scanning and irradiation can be performed even in a narrow space such as in a hollow organ, so that treatment and examination using the laser beam can be performed efficiently and safely.

Also, since the mechanism for scanning the laser beam is very simple and small, a catheter having a built-in laser beam irradiator can also be used with a small diameter, so that the physical condition of the patient undergoing treatment and examination can be improved. The burden can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tip portion showing an embodiment of a laser beam irradiation device of the present invention.

FIG. 2 is a perspective view of a tip portion showing an embodiment of the laser beam irradiation device of the present invention.

FIG. 3 is a front view and a cross-sectional view of the state of FIG. 2;

FIG. 4 is a front view and a sectional view of the state of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser light irradiation apparatus 2 Catheter 3 Optical fiber 4 Tip cap 5 Cantilever 6 Reflective surface 7 Lead wire 8 Heater 9 Collimating lens

Claims (6)

[Claims] 1. A laser light irradiation apparatus comprising: a long insertion portion; a light guide means for guiding laser light into the insertion portion; and a laser light reflection means provided near a tip of the insertion portion. The laser light reflection means includes a cantilever and a reflection surface formed of a substance having a shape memory effect in a flat plate shape,
A laser beam irradiation apparatus, further comprising a heating unit for heating the cantilever. 2. The laser beam irradiation apparatus according to claim 1, wherein said cantilever is made of an omnidirectional shape memory material. 3. The laser beam irradiation apparatus according to claim 1, wherein said cantilever is a bidirectional shape memory material. 4. The apparatus according to claim 1, wherein the cantilever is a one-way shape memory material, and the laser beam reflecting means further includes a bias spring material for applying a force to bend the cantilever. Laser light irradiation device. 5. The laser beam irradiation apparatus according to claim 1, wherein said heating means is formed by laminating a flat heater means on said cantilever. 6. The laser beam irradiation apparatus according to claim 1, further comprising cooling means for supplying and discharging a cooling fluid around the cantilever.