JP3178451B2 - Laser probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a laser scalpel using near infrared laser light as a light source for medical use.
An object of the present invention is to provide a laser probe used in contact with a living body.

[0002]

2. Description of the Related Art A sectional view of a conventional laser probe is shown in FIG. A protective sleeve 1 made of brass is placed in a metal pipe 102 to which a tip 101 made of quartz or sapphire is crimped.
The optical fiber 104 having the resin-coated clad 03
Was inserted and used. The reason why the optical fiber made of resin is used for the cladding is to efficiently transmit light at a wide angle.

In practice, when a laser beam is irradiated in contact with a living body, the temperature of the tip 101 rises to about 800 ° C. At this time, the end face 104a of the optical fiber 104 is
01 (interval less than 0.3 mm), there is a risk that the resin clad 104b is melted by radiant heat from the tip 1. Further, there is a risk that heat is transmitted from the tip chip 101 to the protective sleeve 103 and the buffer 104c of the optical fiber 104 in contact with the protective sleeve 103 is melted.

[0004]

When the tip is brought into contact with a living body and irradiated with a laser, the temperature of the tip rises to about 800 ° C., and the resin clad of the optical fiber close to the tip is melted by radiant heat. There is. In addition, there is a risk that heat is transmitted from the tip to the protective sleeve, and the buffer of the optical fiber in contact with the protective sleeve is melted.

[0005]

In order to solve the above-mentioned problems, a laser probe according to the present invention comprises: a metal pipe to which a tip is crimped; and a light source which is inserted into the metal pipe and has a protective sleeve at a laser emitting end. In a laser probe having a fiber, the metal pipe has one or more vent holes in a section between the front end and the rear end of the protective sleeve, and the rear end of the distal end tip and the front end of the protective sleeve are connected to each other.
And the protective sleeve is in contact with the end face of the optical fiber.
Make sure that the tip of the probe projects at least 0.3 mm.
Is done.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. FIG. 1a is a sectional view of the laser probe, and FIG. 1b is a side view of the protective sleeve.
The distal end of the protective sleeve 3 protrudes at least 0.3 mm or more from the end face 4a of the optical fiber 4, and a thermal insulation distance L1 is taken between the tip 1 and the optical fiber end face 4a. Resin clad 4
b can be prevented from melting.

The inventor conducted the following experiment in order to evaluate the laser probe durability against the protrusion length La of the protective tube 3 from the end face 4a of the optical fiber 4. As shown in FIG. 2, a chromel-alumel thermocouple 9 was attached to the rear end portion of the tip 1 and La was set to 0.1 mm, 0.2 mm, 0.3 mm.
mm, 0.4mm, 0.5mm, output 20W
The temperature of the end of the protective sleeve when the meat piece was irradiated with the continuous wave was measured using the chromer-almer thermocouple 9. As a result, La = 0.1 mm as shown in FIG.
, The cladding 4b was instantaneously melted, and when La = 0.2 mm, the temperature rise was 200 K to 220 K, and the cladding 4b was similarly melted.

However, when La = 0.3 mm, the temperature rise is 100 K to 120 K, and when La = 0.4 mm, the temperature rise is 60 K to 8 K.
At 0K and La = 0.5mm, it becomes 30K-50K and La =
There was no melting of the clad generated at 0.2 mm, and it could be used stably.

As for the material of the protective sleeve 3, stainless steel having a low thermal conductivity is used among metals having excellent machinability, and heat from the tip 1 is transmitted through the protective sleeve 3 and is connected to the protective sleeve 3. The melting of the buffer 4c of the fiber 4 can be prevented. The protective sleeve made of ceramics has a lower thermal conductivity and is more effective. At this time, the connection between the protective sleeve 3 and the optical fiber 4 is performed by screwing the buffer 4c of the optical fiber into a thread provided in the protective sleeve. In addition, a cooling gas is caused to flow in the gap between the metal pipe 2 and the optical fiber 4, and at least one gas vent hole 5 is provided in the metal pipe 2 at least in a section where the protective sleeve 3 is inserted to enhance the cooling effect. it can. Further, when the protective sleeve 3 is in contact with the tip 1, the pressure inside the protective sleeve including the optical fiber 4 rises as the temperature of the tip 1 rises, leading to a further temperature rise. By providing this, air inside the protective sleeve can be released, pressure rise can be prevented, and melting of the resin clad 4b can be prevented.

Next, a second embodiment will be described with reference to FIG. A ceramic ring-shaped member 7 having a thickness of at least 0.3 mm or more is installed between the tip 1 and the protective sleeve 3, and the tip 1 and the optical fiber end face 4a are provided.
By taking a thermal insulation distance L2 between the optical fiber 4 and the resin tip 4, it is possible to prevent the resin clad 4b of the optical fiber 4 from melting due to radiant heat from the tip chip 1.

Next, a third embodiment will be described with reference to FIG. From the place where the rear end of the tip 1 of the metal pipe 2 is located, deform the outer circumference of 0.3 mm,
Deformation part 8 is provided. When the protective sleeve 3 is inserted into the metal pipe 2, the protective sleeve 3 hits the deformed portion 8 and at least 0.3 m between the tip 1 and the protective sleeve 3.
m or more and a thermal insulation distance L3 is provided between the tip 1 and the end face 4a of the optical fiber.
b can be prevented from melting.

[0012]

As is clear from the above description, the laser probe of the present invention can reduce the thermal effect on the resin cladding and buffer of the optical fiber from the heat generated by the tip at the time of actual irradiation. It can be used without causing problems such as burnout of the product.

[Brief description of the drawings]

FIG. 1A is a sectional view of a laser probe according to a first embodiment of the present invention. FIG. 1B is a side view of a protective sleeve.

FIG. 2 is a cross-sectional view of a melting test apparatus for a grad.

FIG. 3 is a characteristic diagram showing a result of a melting experiment of a glad;

FIG. 4 is a sectional view of a laser probe according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a laser probe according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional laser probe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tip 2 Metal pipe 3 Protective sleeve 4 Optical fiber 4a Optical fiber end face 4b Optical fiber resin clad 4c Optical fiber buffer 5 Gas vent hole 6 Notch at protective sleeve tip 7 Ceramic ring member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 18/20

Claims (6)

(57) [Claims] 1. A laser probe comprising: a metal pipe to which a tip is crimped; and an optical fiber inserted into the metal pipe and having a protective sleeve at a laser emitting end.
The metal pipe has one or more vent holes in a section between a front end and a rear end of the protective sleeve, and a tip chip is provided.
The rear end of the pump is in contact with the front end of the protective sleeve, and
The tip of the protective sleeve is less than the end face of the fiber.
A laser probe protruding 0.3 mm or more . 2. The material of the protective sleeve is stainless steel.
The laser probe according to claim 1, wherein: 3. The material of the protective sleeve is ceramics.
3. The laser probe according to claim 2, wherein: 4. A notch is provided at the tip of the protective sleeve.
3. The laser probe according to claim 2, wherein: 5. A small distance between the tip and the protective sleeve.
At least 0.3mm thick heat insulating material is incorporated
2. The laser probe according to claim 1, wherein
Bu. 6. A small distance between the tip and the protective sleeve.
Both have a space of 0.3 mm or more
The laser probe according to claim 1.