JP2008167896A - Medical laser apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical laser apparatus simultaneously attaining the both of a high hemostatic effect and an acute and favorable incision face. <P>SOLUTION: This laser apparatus is provided with a first laser with wavelength of 2.7-3.0 μm having high absorbability to a biotissue and being effective for incision primarily, and a second laser having different wavelength from that of the first laser, showing a relatively low absorbability to the biotissue and being effective for hemostasis. This apparatus generates the respective laser lights on a same optical axis by independently controlling the timings, intervals and shapes of the pulses respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a medical laser device, and more particularly to a laser device used for surgery.

  Up to now, various medical laser devices have been devised that perform incision, transpiration, and hemostasis of living tissue using laser light. When these devices are applied to various treatments, the light absorption coefficient in living tissue varies greatly depending on the wavelength of the laser beam, so it is necessary to select an appropriate wavelength according to the purpose and target of the treatment. For example, when performing soft tissue incision, if a laser beam having a wavelength of 2.7 to 3.0 μm, which is strongly absorbed by moisture contained in a large amount of living tissue, is used, there is no damage to surrounding tissue, so-called sharp incision. It is possible. However, if a sharp incision is made using a laser with high absorption, a coagulation layer is not formed and the hemostatic effect is low, so another means of hemostasis is required.

On the other hand, in order to stop hemostasis, a laser beam having a wavelength of about 1 to 2 μm, which does not absorb much moisture, is used. This is because when the tissue is irradiated with a laser beam with low absorption, the laser beam penetrates deeply into the tissue and forms a coagulation layer that seals the capillaries around the irradiated area. However, when the incision is performed with a low-absorption laser, the incision is severely damaged. As a means to solve these problems, a medical laser device that can irradiate laser beams with different wavelengths has been devised.
JP 2002-125982 A

  Conventionally proposed medical laser devices capable of irradiating laser beams with different wavelengths generate laser beams with different wavelengths at the same time. The affected part is simultaneously irradiated with laser pulses of wavelength. When a living tissue is incised using such a laser device, even if a coagulation layer is formed with a low absorption laser, the coagulation layer is also evaporated by the simultaneously irradiated laser beam with high absorption. High hemostatic effect cannot be obtained.

  In order to solve the above problems, the present invention provides a medical laser including a first laser having an oscillation wavelength of 2.7 to 3.0 μm and a second laser that oscillates at a wavelength different from the first laser. Provided is a medical laser device characterized in that a time lag is generated between pulses of a first laser and a second laser.

  The medical laser device includes a first laser having an oscillation wavelength of 2.7 to 3.0 μm and a second laser that oscillates at a wavelength different from the first laser, The medical laser device may be characterized in that the pulse repetition frequency of the second laser is different.

  A medical laser device comprising a first laser that oscillates at a wavelength of 2.7 to 3.0 μm and a second laser that oscillates at a wavelength different from the first laser, the second laser It may be a medical laser device characterized by a continuous wave.

  A medical laser device having any of the above three configurations, comprising a single hollow optical fiber for transmitting the first laser and the second laser, wherein the hollow optical fiber includes a first laser. And an internal dielectric film that reduces loss at both wavelengths of the second laser and the second laser may be formed.

  The medical laser device according to any one of the above three configurations may include a visible aiming light source.

  A medical laser device having any one of the above three configurations, characterized by comprising a visible aiming light source, wherein the first laser, the second laser, and a single beam for transmitting visible aiming light A hollow optical fiber is provided, and an internal dielectric film is formed on the hollow optical fiber so as to reduce loss at all wavelengths of the first laser, the second laser, and the visible aiming light source. Or a medical laser device.

  The medical laser device of the present invention can irradiate laser beams of a plurality of wavelengths, and independently controls the pulse shape and interval of these laser beams, thereby providing a high hemostasis effect and a sharp and good cut surface. There is an advantage that both can be realized simultaneously.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a medical laser apparatus showing an embodiment of the present invention. This apparatus has a laser resonator 1 having a wavelength of 2.7 to 3.0 μm. As a laser medium of this resonator, Er: YAG oscillating at a wavelength of 2.94 μm, Er: YLF of 2.8 μm, 2 A typical example is 79: m Er: YSGG. Further, this apparatus has a laser resonator 2 having a high hemostatic effect. As this laser medium, Ho: YAG having a wavelength of 2.08 μm (sometimes called CTH: YAG), 1.06 μm of Nd: YAG is a typical one.

  An excitation light source 3 is attached to the laser resonator 1, and an excitation light source 4 is attached to the laser resonator 2, and power sources 5 and 6 are provided for driving them. These power supplies 5 and 6 generate voltage pulses in synchronization with external pulse inputs, and have a pulse generator 7 for this purpose. The output from the pulse generator is directly connected to the power source 5 that drives the laser resonator 1, while it is connected to the power source 6 that drives the laser resonator 2 via a pulse delay device 8.

  After the output light from the laser resonator 1 passes through the beam splitter 9, the output light from the laser resonator 2 is reflected by the reflecting mirror 10 and the beam splitter 9, and then condensed by the lens 11 to be collected by the optical fiber 12. Is incident on. The optical fiber 12 can transmit light of both wavelengths of the first laser and the second laser with high efficiency, and a hollow optical fiber is preferable. When a hollow optical fiber is used as the optical fiber 12, high flexibility is obtained by setting the inner diameter to about 0.2 to 1.0 mm, and high by setting the length to 0.8 to 2.5 m. It is possible to obtain operability and moderate laser output.

  Figure 2 shows the time variation of the laser pulse output generated from this laser device. There is a pulse time offset provided by the pulse delay device 8 between the optical output 13 of the first laser effective for incision and the optical output 14 of the second laser effective for hemostasis. When both laser outputs are irradiated at the same time, the coagulation layer formed by the second laser irradiation is evaporated by the first laser irradiated at the same time, and the hemostatic effect is reduced. By setting the pulse delay as shown in FIG. 2, hemostasis by the second laser can be performed immediately after the incision is performed by the first laser.

  The repetition frequency of the light pulses generated from the first laser and the second laser is preferably about 3 to 20 Hz, but may be a higher frequency. The first laser has a high incision ability with a pulse width of about 200 to 300 μsec, whereas the longer the pulse width of the second laser is about 250 to 1000 μsec, the higher the hemostatic effect. The laser outputs of the first laser and the second laser are preferably set independently so as to be optimum depending on the object and purpose of application of the laser apparatus.

  FIG. 3 shows an example of the temporal change of the laser pulse output generated from this laser apparatus. The pulse repetition frequency of the optical output 13 of the laser 1 effective for incision and the optical output 14 of the laser 2 effective for hemostasis. Are different. With this setting, it is possible to make an incision with the light output 13 while effectively forming a solidified layer formed gradually with the light output 14. It is desirable that the repetition frequency of the optical output 13 is about 3 to 10 Hz, whereas the repetition frequency of the optical output 14 is as high as about 5 to 20 Hz. In this case, since the pulse timings of the first laser and the second laser need not be synchronized, the first laser and the second laser may be driven by independent pulse generation sources. .

  FIG. 4 shows an example of the temporal change of the laser light output generated from this laser apparatus. The light output 13 of the first laser effective for incision is pulsed, whereas it is effective for hemostasis. The optical output 14 of the second laser is a continuous wave. With this setting, it is possible to make an incision effectively with the pulsed light output 13 while continuously forming a solidified layer with the light output 14. In this case, the first laser and the second laser may be driven independently. As the second laser, a semiconductor laser that generates near-infrared light and visible light, a carbon dioxide gas laser with a wavelength of 10.6 μm, and the like can be used.

  The optical fiber 12 that transmits both the first laser and the second laser needs to have high transmission efficiency at both wavelengths and high flexibility and durability so that it can be adapted to laser surgery. There is. A hollow optical fiber in which a metal thin film and a dielectric thin film are formed on the inner surface of a tube made of glass or plastic is suitable as the optical fiber 12, but by designing the thickness of the dielectric appropriately, a plurality of It is possible to achieve low loss at a wavelength of.

  FIG. 5 shows a hollow produced by designing the thickness of the inner dielectric so as to reduce the loss in both the laser 1 having a wavelength of 2.8 to 3.0 μm and the Nd: YAG laser having a wavelength of 1.06 μm. This is the loss spectrum of an optical fiber. A polymer is used as the inner dielectric, and it is necessary to finely adjust the thickness of the polymer film between 0.25 and 0.35 μm. The polymer used is preferably a material having low absorption at both wavelengths of the first laser and the second laser.

  In the medical laser device of the present invention, in addition to the first laser that is effective for incision and the second laser that is effective for hemostasis, the portion irradiated with invisible infrared laser light is visually observed. It is preferable to have a light source that generates visible aiming light. Semiconductor lasers and light-emitting diodes are suitable as aiming light sources.

  The visible aiming light source is made incident on the optical fiber 12 by arranging a reflecting mirror or the like so that the optical axis is the same as that of the first laser and the second laser. In addition to the wavelengths of the first laser and the second laser, the optical fiber 12 needs to exhibit high transmission efficiency at the wavelength of visible aiming light. When a hollow optical fiber is used as the optical fiber 12, Therefore, it is necessary to set the dielectric film thickness so that the loss is low even for visible aiming light. The hollow optical fiber whose loss spectrum is shown in FIG. 5 is designed and manufactured to have a low loss even at the wavelength of a red laser diode or helium neon laser having a wavelength of 0.6 μm. Is suitable as a transmission line for medical laser devices equipped with a visible aiming light source.

It is a block diagram of the medical laser apparatus which shows embodiment of this invention. It is explanatory drawing which showed the time change of the laser pulse output generated from this laser device. It is explanatory drawing which showed the time change of the laser pulse output generated from this laser device. It is explanatory drawing which showed the time change of the laser pulse output generated from this laser device. It is explanatory drawing which showed the loss spectrum of the hollow optical fiber which is a part of the structure of this laser apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser resonator 2 Laser resonator 3 Excitation light source 4 Excitation light source 5 Excitation light source drive power source 6 Excitation light source drive power source 7 Pulse generator 8 Pulse delay device

9 Beam splitter 10 Reflector

DESCRIPTION OF SYMBOLS 11 Lens 12 Optical fiber 13 Optical output of laser resonator 1 14 Optical output of laser resonator 2

Claims (6)

  A medical laser device including a first laser having an oscillation wavelength of 2.7 to 3.0 μm and a second laser that oscillates at a wavelength different from the first laser, the first laser and the second laser A medical laser device characterized in that a time lag is generated between pulses of the laser.   A medical laser device including a first laser having an oscillation wavelength of 2.7 to 3.0 μm and a second laser that oscillates at a wavelength different from the first laser, the first laser and the second laser A laser device for medical use, characterized in that the pulse repetition frequency of different lasers is different.   A medical laser apparatus comprising a first laser that pulsates at a wavelength of 2.7 to 3.0 μm and a second laser that oscillates at a wavelength different from the first laser, the second laser being continuous A medical laser device characterized by being a wave.   4. The medical laser device according to claim 1, further comprising a single hollow optical fiber for transmitting the first laser and the second laser, wherein the hollow optical fiber includes a first hollow optical fiber. The medical laser device according to any one of claims 1 to 3, wherein an internal dielectric film is formed so that loss is reduced at both wavelengths of the laser of the first laser and the second laser.   The medical laser device according to any one of claims 1 to 3, further comprising a visible aiming light source.   6. The medical laser device according to claim 5, comprising a first laser, a second laser, and a single hollow optical fiber for transmitting visible aiming light, wherein the hollow optical fiber includes a first hollow optical fiber. 6. The medical laser device according to claim 5, wherein an inner dielectric film is formed so as to reduce loss at all wavelengths of the laser of the first laser, the second laser, and the visible aiming light source.

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