JPH01153166A - Laser probe - Google Patents

Abstract

PURPOSE:To enable even irradiation with laser and to provide stabled irradiation condition by making a condensing lens changeable of the focusing point by moving it before and behind to a light introducing tip for discharge with retractable operations. CONSTITUTION:The light introducing tip 6 is constituted so that laser beam enters from the bottom 8 and emits from a circular cone 9. The laser beam introduced by laser guide 4 enters into the light introducing tip 6, and most of it is reflected totally on the inner surface of the circular cone 9, followed by further reflection on the inner surface of the circular cone 9. By repeating such reflections, laser beam reaches the top with gradual converge. When the incident angle against the inner surface of the circular cone 9 exceeds the total reflexion angle, laser beam is released in a ring form from the circular cone 9. Before the laser beam reaches the top-most part of the light introducing tip 6, it is released from the part of the circular cone 9. Thus, laser is directed onto a ring form area e with little release towards anterior sine of the central axis. Thus, laser can be directed efficiently and evenly even to the peripheral area which require irradiation, avoiding irradiation of unnecessary sites.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser probe used for treating, for example, the inner wall of a blood vessel or a polyp-like body part with laser light.

[Prior Art] This type of laser probe generally has a light focusing chip at the tip of the sheath, which focuses the laser light emitted from the laser guide and irradiates it onto the irradiated area. ing. This light focusing chip: Example! f
P CT W O85/ 05282 1:: As is known, it is formed in the shape of a truncated cone, and the laser beam is emitted from the tip surface while being repeatedly totally reflected by the tapered inner surface to prevent it from leaking. . Therefore, the laser beam has a strong directivity that emits light in a focused direction in front of the laser probe.

[Problems to be Solved by the Invention] However, this laser probe has a strong directivity that emits laser light in a concentrated manner to a single point directly in front of the patient. It is difficult to irradiate against. In other words, the emitted laser light intensively irradiates the center of the blood vessel, which does not require irradiation, and the intensity of the laser light is rather weak against the inner circumferential wall of the blood vessel. Furthermore, in order to direct the center of the emitted laser beam toward the inner circumferential wall of the blood vessel, it is usually difficult to do so, and the irradiation must be performed in an extremely unstable state.

For this reason, in the conventional laser probe, treatment of peripheral areas that require laser beam irradiation is inefficient, the irradiation treatment operation is unstable, and there is also a risk of irradiating unnecessary areas.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to have a simple structure, but it also aims to irradiate laser beams to the side and peripheral areas where laser beam irradiation is required for any size of affected area. It is an object of the present invention to provide a laser probe that can irradiate efficiently and uniformly, perform irradiation in a stable irradiation state, and avoid the danger of irradiating unnecessary areas.

[Means and effects for solving the problem] In order to solve the above problem, the laser probe of the present invention has a built-in laser guide, and the laser beam emitted from the tip of the laser guide is incident on the bottom surface of the probe. A conical light-guiding chip for emission is provided, which converges the laser beam received from the laser beam and emits it in a ring shape from the circumferential surface of the cone before reaching the tip. A condensing lens that can move forward and backward with respect to the optical chip is provided, and the condensing lens can be moved back and forth with respect to the light-emitting light guide chip by an advance and retreat operation means to change the focal position.

By moving the condensing lens forward and backward relative to the light-guiding chip in this way, it is possible to efficiently and reliably detect, for example, thrombus or polyp-like diseased areas on the inner wall of blood vessels, regardless of their size. Can be irradiated.

[Embodiment] FIG. 1 shows a first embodiment of the present invention. 1st
1 in the figure is a laser probe, and this laser probe 1
is inserted into the body cavity a through an insertion channel of an endoscope (not shown) or alone. Further, 2 in FIG. 1 is a sheath of the laser probe 1.

A tip holding tip 3 is attached to the tip of the sheath 2, and the tip of the laser guide 4 is fitted into and fixed to the tip holding tip 3.

The laser guide 4 is inserted into the inside of the sheath 2, guided to the hand side, and connected to a laser light source device (not shown). Note that at the tip of the laser guide 4, a light guiding portion 5 consisting of a core and a cladding is exposed and protrudes.

Furthermore, the tip holding tip 3 has a light guiding tip 6 which will be described later.
A tip holder 7 for attaching the tip is fixedly attached by screwing. The light-guiding chip 6 is made of, for example, sapphire and is formed into a conical shape, and the laser light emitted from the laser guide 4 enters through the bottom surface 8 and is emitted from the conical circumferential surface 9 . Furthermore, this light guiding chip 6
The cone angle is set to such an extent that the incident laser beam is converged and emitted from the conical peripheral surface 9 in a ring shape before reaching the tip.

Further, an outer skin 11 is fitted around the outer periphery of the sheath 2 so as to be able to move forward and backward. This outer skin 11 is moved forward and backward by an operation mechanism (not shown) provided on the proximal side of the laser probe 1, thereby constituting a forward and backward operation means for advancing and retracting a condensing lens 12, which will be described later. The condenser lens 12 is attached to the tip of the outer skin 11 via a lens frame 13. The condensing lens 12 is configured to condense the laser beam emitted in a ring shape from the light guiding chip 6 described above. By adjusting the forward and backward positions of the condensing lens 12, the focal position can be changed and the size of the ring-shaped laser beam can be varied.

As shown in FIG. 1, the laser light guided by the laser guide 4 enters the light guiding chip 6, and most of it is totally reflected on the inner surface of the conical circumferential surface 9. Most of the reflected laser light is further reflected on the inner surface of the conical circumferential surface 9.

After repeated reflections in this way, the laser beam is gradually converged and reaches the tip side, but if the angle of incidence with respect to the inner surface of the conical circumferential surface 9 exceeds the angle of total reflection, it is transmitted without being totally reflected, and the laser beam is transmitted through the conical circumferential surface 9. It is released in a ring shape from the outside. and,
Laser light is emitted from the conical peripheral surface 9 before reaching the leading edge of the light guiding chip 6. Therefore, almost no radiation is emitted in front of the central axis, and the ring-shaped range e around the front is irradiated. Therefore, as shown in FIG. 1, if the irradiation is directed toward a polyp-like diseased area formed within the body cavity a, the irradiation will surround the affected area. By adjusting the advancing and retracting positions of the condensing lens 12, the distance from the distal tip 6 can be changed, and the diameter of the ring-shaped irradiation range e can be adjusted to match the size of the affected area.

Note that this selection of the irradiation range e is determined in advance by irradiating the guide light.

In this way, hyperthermia can be performed by irradiating laser light from the surrounding area around the affected area of cancer, etc. and heating it, for example. The entire cancer-affected area can be heated evenly, allowing efficient treatment.

Furthermore, even in the case of performing ablation treatment, by changing the position of the condenser lens 12, the laser beam can be sequentially irradiated from the outside to the inside of the affected area for efficient treatment.

On the other hand, when used on a blood vessel, the ring-shaped irradiation range e can intensively irradiate the blood vessel wall. Therefore, thrombi and the like can be efficiently treated regardless of their size. Furthermore, since there is no need to purposely direct the light-guiding tip 6 of the laser probe 1 toward the blood vessel wall, the treatment can be performed reliably in a stable state.

FIG. 2 shows a second embodiment of the invention. In this embodiment, the central axes of the light guiding portion 5 of the laser guide 4 and the condensing lens 12 are eccentric with respect to the central axis of the light guiding chip 6. As a result, the laser light emitted from the light guide chip 6 in a ring shape is not a ring shape with an even full width,
It forms a ring shape that is strong only in one direction. Further, this light is focused and irradiated toward one side by an eccentric condensing lens 12. Note that this condensing lens 12 can be rotated by rotating the outer cover 11, so the direction of irradiation can be freely selected at hand.

In the second embodiment of the present invention, the light guiding portion 5 of the laser guide 4 is provided rotatably around the central axis of the sheath 2, and the light guiding portion 5 rotates around the central axis of the sheath 2. It may be possible to rotate it.

[Effects of the Invention] As explained above, according to the laser probe of the present invention,
Laser light is emitted in a concentrated manner around the front rather than directly in front of the front. For this reason, it is possible to efficiently and uniformly irradiate a polyp-like diseased area or a thrombus on the inner peripheral wall of a blood vessel with laser light, regardless of its size, to the side and periphery that requires laser light irradiation. Moreover, it can be carried out under stable irradiation conditions, and the danger of irradiating unnecessary areas can be avoided.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of the distal end portion of the first embodiment of the present invention in a used state, and FIG. 2 is a side sectional view of the distal end portion of the second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Laser probe, 2... Sheath, 4... Laser guide, 6... Light guide chip, 8... Bottom surface, 9...
・Conical circumferential surface, 11... Outer skin, 12... Condensing lens,
a... Body cavity, e... Irradiation range. Applicant's representative Patent attorney Atsushi Tsuboi Figure 1 Figure 2

Claims (1)

[Claims] A cone that receives laser light emitted from the tip of the laser guide from the bottom surface of the probe that has a built-in laser guide, converges the laser light, and emits it in a ring shape from the shoulder surface of the cone before reaching the tip. A light-guiding chip for emission is provided in the shape of a shape, and a condensing lens is provided in front of the light-guiding chip for emission, which can move forward and backward with respect to the light-guiding chip.
A laser probe characterized in that the condensing lens is moved back and forth with respect to the emitting light guiding chip by an advancing/retracting operation means so that the focal position can be changed.