JPH0412743A - Laser probe - Google Patents

Abstract

PURPOSE:To always allow the irradiation spot to follow up a position to be treated by providing a tip chip which is arranged so as to be freely and linearly advanceable in the optical axis direction on the emitting end side of a light guide, condenses and radiates a laser beam, and also, irradiates the living body part therewith, and a spring for energizing forward the chip. CONSTITUTION:The tip of the light guide 2 is fixed to the tip of a sheath 1 through a support ring 3. On an optical axis (l) in front of the emitting end face 4, a tip chip 5 is installed, attached to the supporting ring 3 through a coil spring 6 and can move forward/backward freely, and also, and it is usually in the most protruding state. The inside surface of the tip side part of a hole 10 of the tip chip 5 is formed in a tapered shape, and by reflecting a laser beam L emitted from the emitting end face 4 of the light guide 2, it is condensed by using the center of a tip opening 12 as a condensing spot P. That is, without executing an operation for pushing in the sheath 1, the tip face 13 of the tip chip 5 advances to the part of a deep layer in which incision advances, the condensing spot P is positioned in the tissue part in which incision is executed from that time, and a living body tissue 14 can be incised.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser probe that is inserted into a body cavity, for example, endoscopically, and is used to treat tissue by irradiating laser light onto an affected area.

[Prior Art] Generally, this type of laser probe has a laser light guide inserted into a sheath and a tip provided at the tip of the sheath, and the laser beam guided through the laser light guide is directed to the tip. The beam is focused and emitted in a spot-like manner towards the surface of the body part to be incised. In this case, in order to stabilize the spot irradiation position, positioning is performed by applying the distal tip to the body part (see Japanese Patent Laid-Open No. 62-5341).

[Problems to be Solved by the Invention] However, when incising tissue while pressing the distal tip against a living body part, as the incision of the living tissue progresses due to the irradiated laser light, the spot position of the laser light and the next incision occur. This creates a distance between the target tissue and the tissue, reducing the ability to make an incision. Therefore, it was necessary to operate the laser probe at hand and repeat the pressing operation to advance the tip forward.

However, this operation is a delicate and highly skilled work that is performed under observation with an endoscope, and has the disadvantage that the work efficiency is significantly reduced.

The present invention has been made with attention to the above-mentioned problem, and its purpose is that once the tip is pressed against the treatment area, the irradiation spot of the laser beam will always be on the treatment site without any special manual work. The object of the present invention is to provide a laser probe that follows a desired position.

[Means and effects for solving the problem] In order to solve the above problem, the laser probe of the present invention has the following features:
The light guide, which transmits the laser light, is arranged to be movable forward and backward in the direction of the optical axis at the output end side of the light guide, and has a means for irradiating the tissue with the laser light received from the light guide, and has an abutting surface for contacting the biological part. The device is provided with a distal tip that has been moved forward, and a means for biasing the distal tip forward when it is in a retracted position.

Once the distal tip is pressed against the treatment site, the laser beam irradiation spot always follows the position to be treated without any special work.

[Embodiment] FIGS. 1 to 3 show a first embodiment of the present invention. In the figure, 1 is a flexible sheath.
A flexible light guide 2 made of a single optical fiber element is inserted into the interior of the optical fiber. The light guide 2 is composed of a single core and a cladding covering the outer surface of the core, and the outer periphery of the core is further covered with a resin material. In addition, this light guide 2
Alternatively, an optical fiber bundle formed by bundling a plurality of optical fiber elements may be used.

The tip of the light guide 2 is fixed to the tip of the sheath 1 via a support ring 3. The base end of the light guide 2 is connected to, for example, an excimer laser light source via a connector (not shown).

Furthermore, a tip 5 is installed in front of the output end face 4 of the light guide 2 at a location on the output optical axis g. The distal tip 5 is attached to the support ring 3 via a coil spring 6. The coil spring 6 is arranged concentrically with the optical axis g. The tip of the coil spring 6 is fitted into and fixed to the outer periphery of a small diameter part 7 formed at the rear end of the tip 5, and the rear end of the coil spring 6 is fitted into a small diameter part 8 formed at the front end of the support ring 3. It is fixed with. Since the distal tip 5 is thus supported by the coil spring 6 as a biasing means, it can freely move forward and backward in the direction of the optical axis g, and is normally in the state shown in FIG. 1 in which it protrudes the most.

The tip 5 has a hole 10 penetrating along the optical axis p direction.
is formed. The inner surface of the distal end portion of the hole 10 is formed into a tapered shape that becomes narrower toward the distal end, and the reflective surface 8 is formed by this conical inner surface. This reflective surface 8 reflects the laser light that has been emitted from the emitting end surface 4 of the light guide 2 and has proceeded along the emitted optical axis g.
The center of the tip opening 12 of 0 is set as a condensing spot P, and a means for condensing the light onto this spot P is constituted. The tip opening 12 of the hole 10 opens at the center of the tip surface 10 of the tip 5.

The laser probe according to this embodiment is introduced into a body cavity through a channel of an endoscope and used to incise living tissue 14.

That is, this laser probe is inserted into the body cavity and the second laser probe is inserted into the body cavity.
As shown in the figure, the distal end surface (abutment surface) 13 of the distal tip 5 is pressed against the surface region of the living tissue 14 to be incised.

As a result, the coil spring 6 is compressed, and the distal tip 5 is in contact with the surface portion of the living tissue 14 with a constant pressing force. Therefore, the distal tip 5 is held at a predetermined position in the living tissue 14.

Therefore, when the excimer laser light source is operated in oscillation mode, the excimer laser light is transmitted through the light guide 2, exits from the output end face 4, and travels along the output optical axis Ω. Then, the light is reflected by the reflective surface 11 of the tip 5 and condensed into a condensing spot P located at the center of the tip opening 12 of the hole 10 .

Since this focused spot P is located on the tip surface 13 of the tip 5, the excimer laser light is transmitted to the tip 5.
The light is focused on the surface area of the biological tissue 14 that comes into contact with the distal end surface 13 of the body tissue 14 to make an incision.

As this incision progresses and the incision goes deeper as shown in FIG. 3, the compressed coil spring 6 expands, causing the distal tip 5 to follow.

In other words, without pushing the sheath 1 of the laser probe on the hand side, the distal end surface 13 of the distal tip 5 advances toward the deep region where the incision has progressed, and always focuses the focused spot P of the excimer laser light. By positioning it at the tissue portion to be incised, the living tissue 14 can always be incised in the best condition.

Note that excimer lasers are suitable for body cavities such as blood vessels because they are difficult to absorb into water, especially when a medium gas of XeC, Q (wavelength: 308 nll) or XeF (wavelength: 351 ni) is used. Also, in treatment, Y
Unlike an AG laser, it does not have a thermal effect on normal tissue. Furthermore, the excimer laser can also be applied to a light guide using an optical fiber bundle, as in the example described later.
In this case, the flexibility of the laser probe can be improved.

FIG. 4 shows a second embodiment of the invention. In this embodiment, a long cylindrical body 15 is used, and a device similar to that of the distal tip 5 is incorporated in the distal end portion of this body. That is, a tapered reflective surface 11 is formed along with the hole 10 at the tip of the cylindrical body 15, and a tip surface 13 is formed at the tip. Further, the center of the tip opening 12 of the hole 1O is set as the condensing spot P. The proximal end portion of the cylindrical body 15 is inserted into the sheath 1 and attached so as to be movable forward and backward in the direction of the output optical axis g. Inside the sheath 1 is the cylindrical body 15.
A coil spring 6 is provided to bias the front side forward. The tip of the coil spring 6 is fixed to the cylindrical body 15, and the rear end of the coil spring 6 is fixed to the ring 1 fixedly incorporated in the sheath 1.
It is fixed at 6. Thus, the cylindrical body 15 can move forward and backward in the direction of the optical axis g, and protrudes by a certain length due to the biasing force of the coil spring 6. Normally, it is in the most protruding state shown in FIG. Other points are as described in 1 above.
This is similar to that of the embodiment. This second embodiment can also be used in the same manner as described above, and the same effects can be obtained. Moreover, in this embodiment, since the cylindrical body 15 is guided along the inner surface of the sheath 1, the cylindrical body 15 can be accurately slid in the direction of the optical axis g.
There is no meandering or wobbling like in the case where the coil spring 6 is used as the support as in the embodiment shown in FIG.

FIG. 5 shows a third embodiment of the invention. In this embodiment, the taper inclination angle of the reflecting surface 11 in the above-mentioned first embodiment is made smaller so that the laser light is reflected multiple times and then focused on the focused spot P. is the same as that of the first embodiment.

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, a convex condensing lens 21 is provided in place of the reflecting surface 11 in the above-described embodiment, and this is used as a condensing means. In this case, the tip 5 constitutes a lens frame. Note that the condensing means having this configuration may be incorporated into the cylindrical body 15 of the second embodiment.

FIG. 7 shows a fifth embodiment of the present invention. In this embodiment, the light guide 2 in the first embodiment described above is constructed of an optical fiber bundle, and a tube 26 forming an insertion lumen 25 is inserted through the center of the optical fiber bundle.

A guide wire (not shown) can be inserted through this insertion lumen 25 over the coil spring 6 and the hole 10 of the distal tip 5. According to this, a guide wire is introduced into the body cavity in advance, and the laser probe can be introduced into the body cavity using the guide wire as a guide.

Note that the present invention is not limited to the above embodiments. For example, the biasing means described above may be a leaf spring, a torsion spring, or the like in addition to the coil spring, or may be an elastic member such as rubber, which is not limited to a spring. Furthermore, the type of laser light is not particularly limited, and may be a laser diode, for example. Further, the condensing means in the tip tip is not limited to one that simply reflects the laser beam on the outer surface, but may also reflect it on the inner surface of a light-transmitting body or transmit it by refraction.

[Effects of the Invention] As explained above, according to the present invention, once the tip is pressed against the treatment area, the irradiation spot of the laser beam always moves to the new area to be treated without any special work. It is possible to follow the instructions and perform reliable treatment quickly with simple operations.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a longitudinal sectional view of the vicinity of the tip of the laser probe, and FIGS. 2 and 3 are the tips of the laser probes in use. It is a vertical cross-sectional view of the vicinity. FIG. 4 is a longitudinal sectional view of the vicinity of the tip of a laser probe showing a second embodiment of the present invention. FIG. 5 is a longitudinal sectional view of the vicinity of the tip of a laser probe showing a third embodiment of the present invention. FIG. 6 is a longitudinal sectional view of the vicinity of the tip of a laser probe showing a fourth embodiment of the present invention. FIG. 7 is a longitudinal sectional view of the vicinity of the tip of a laser probe showing a fifth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Sheath, 2... Light guide, 5... Tip tip, 6... Coil spring, 7... Hole, 8... Reflective surface, 14... Living tissue, 13...・Tip surface, 15...
Cylindrical body, P... Light focusing spot. Figure hi6 h Otsu

Claims (1)

[Claims] A light guide for transmitting laser light; and a means for irradiating tissue with the laser light received from the light guide, the light guide being movable forward and backward in the direction of the optical axis at an output end side portion of the light guide; A laser probe comprising: a distal tip having an abutting surface; and means for biasing the distal tip forward when it is in a retracted position.