Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
  • A61B18/22—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
  • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
  • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
  • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
  • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
  • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
  • B23K26/0643—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising mirrors
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4202—Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
  • G02B6/4203—Optical features
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4296—Coupling light guides with opto-electronic elements coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
  • A61B18/22—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
  • A61B2018/2255—Optical elements at the distal end of probe tips

Definitions

• This invention relates to a medical and surgical laser probe and more particularly to a medical and surgical laser probe with a conically tapered rod connected to the tip end of an optical fiber extending from a body of a medical and surgical laser system.
• non-contact type laser irradiation system using an optical fiber for carrying out incision of tissue of a living organism by irradiating laser beam through the optical fiber without contacting the affected part of the tissue.
• This type of non-contact laser irradiation system effects incision and coagulation by irradiating laser beam such as YAG laser, Ar laser, etc. from the tip end of an elongated quartz core, laser beam guide, made of a single quartz fiber connected optically to a laser source.
• Such a non-cntact laser irradiation system is rather poor in operating efficiency because it effects the incision without contacting the tissue and without confirming or inspecting the incision condition.
• This conventional laser irradiation system has another problem that reproducible irradiation effect can not always be obtained. In general, it is required to keep a distance between the tip end of the optical fiber and the tissue to be constant to provide laser beam irradiation of constant energy density.
• it is difficult to keep the distance constant, and especially it is difficult to control a distance from the tissue when the system is applied to a laser treatment through an endoscope.
• the non-contact irradiation system has such a fatal disadvantage that the laser beam is backscattered from the surface of the tissue and a considerable percentage of the irradiated laser beam energy is lost.
• the quartz core is kept in contact with the tissue during the irradiation of laser beam, heat is generated at the contact portion and the end of the quartz core is burnt and broken.
• the conventional laser system in contact with the tissue.
• the divergency angle of laser beam irradiated from the conventional quartz core is as narrow as 7 to 10°, the energy density is not lowered so much even at a position distanced from the irradiation point.
• laser beam of high energy density is irradiated to the tissue around the portion which is being subjected to incision, too, to cause necrosis thereof.
• a quartz rod formed in a tapered shape so as to allow laser beam to leak out from the tapered surface and let laser beam component from the tip end thereof irradiate onto the tissue in contact with the tissue.
• this quartz rod the energy density of the laser beam emitted from the tip end of the rod is rather low because of the leakage of laser beam from the tapered surface, so that incision of the tissue cannot be effected with high efficiency.
• a medical and surgical laser probe having a laser beam transmitting member connected optically to a laser source and a laser beam emitting rod member optically connected to the laser beam transmitting member: which probe is characterized in that said rod member is made of an artificial saphire and comprised of a laser beam receiving portion and a tapered portion having a laser beam emitting tip end face; and the length and the taper angle of the tapered portion and the radius of the tip end face of the tapered portion are determined so that substantially all laser beam incident on the columnar portion from the laser beam transmitting member is emitted from the tip; end face of the tapered portion without leaking out from the tapered face of the tapered portion.
• the medical and surgical laser probe of the present invention is capable of being used in contact with the tissue so that the operation efficiency can be improved very much and capable of effecting the incision and coagulation of the tissue without causing any malaffection onto other tissues.
• Fig.1 is a perspective view of a laser probe according to the present invention
• Fig.2 is a sectional view of the laser probe of Fig.1;
• Fig.3 is a diagram showing the propagation of laser beam inside the tapered portion of the laser probe according to the present invention
• Fig.4 is an explanatory view showing the laser irradiation onto the tissue by a conventional laser irradiation system
• Fig. 5 is a similar explanatory view showing the irradiation of laser beam onto the tissue by the laser probe of the present invention
• Fig. 6 to 9 are schematic views of various modifications of the rod members according to the present invention.
• Figs. 10(a) to c) are explanatory views showing the laser irradiation onto the tissue by using the rod member as illustrated in Fig. 8; and Fig. 11 is a sectional view of the mounting structure of the rod member as illustrated in Fig. 9.
• Figs. 12-Fig.l4 are fragmentary enlarged views of the probe tip illustrating various configurations for the bubble melt. PREFERRED EMBODIMENT OF THE INVENTION
• Fig. 1 is a perspective view of a laser probe or laser rod embodying the present invention and Fig. 2 is a sectional view of the same.
• the laser rod 1 is comprised of a tip rod member 2 and a holder 3.
• the rod member 2 is fixed to the holder 3 by a fixing coupler 4.
• An optical fiber extends within the holder 3 and the end thereof, from which the laser beam is emitted, is fixed to the holder 3 by a support 6 in such a manner that the optical axis of the optical fiber 5 and the optical axis of the rod member 2 are aligned with each other.
• the optical fiber 5 is led to the outside through a holder grip portion 7 and connected to a laser beam source (not shown).
• the leading-out portion of the fiber 5 is fixed by a fixing member 8 fitted to the holder grip portion 7.
• the rod member 2 is made of a single crystal artificial saphire and comprised, for example, of a columnar portion 9 supported by the holder 3 and a tapered portion 10 having a tip end face from which laser beam is emitted.
• the artificial saphire is formed into the rod member 2 of the present invention in such a manner that the C-axis of the crystalline structure of the artificial saphire is disposed along the longitudinal direction of the rod member 2.
• the artificial saphire of the present indention has characteristics as summarized in the following:
• the artificial saphire of this kind may be obtained by any suitable means such as a zone melting method or Verneuil method.
• the Verneuil method is advantageous over the zone melting method in respect with light transmission and therefore Verneuil method is preferably employed to manufacture the artificial saphire of the present invention.
• the material i.e., Al 2 O 3 powder is subjected to melting at a temperature of about 2040°C and dropped by gravity through a nozzle to allow crystallization to take place.
• the artificial saphire employed for the rod member 2 has such advantages that it is physiologically neutral, has high mechanical strength, high hardness, high laser beam transmission, excellent thermal resistance and low thermal conductivity and is free from tissue adhesion, which are all required for the material of the rod member of the laser probe.
• the thermal conductivity of the artificial saphire is as low as 1/10 of the thermal conductivity of the quartz which is heretofore used for a conventional laser irradiation system. This feature enables the laser probe to be used in contact with the tissue.
• the tapered portion of the rod member 2 has such a configuration that the incident laser beam from the fiber 5 is not leaked out from the side of the tapered portion and all emitted from the tip end face of the tapered portion.
• Such a configuration of the rod member 2 is obtained by adjusting the length of the tapered portion 10, the taper angle and the diameter of the tip end face of the tapered portion 10 so as to satisfy the required conditions.
• a laser beam component A emitted from the quartz laser beam transmitting material, i.e., optical fiber 5 at a divergency angle of ß is incident on the end face of the columnar portion 9 of the rod member 2 at an incident angle of ß/2, refracted at a refraction angle of Y , propagated through the rod member 2 and emitted from the verge of the tip end face of the tapered portion 10 after repeated (n times) total reflection, will now be considered.
• the conditions are critical for emitting all laser beam incident on the rod member 2 only from the tip end face bf the tapered portion without leaking out from the tapered face of the portion 10 .
• the taper angle of the tapered portion 10 is now assumed as ⁇ and the radius of the tip end face is assumed as R and the critical angle for emitting laser beam from the artificial saphire into air is assumed as ⁇ . If the radius of the tapered portion 10 at a first reflection point from the emitting end (the last reflection point from the laser receiving end ) is R 1 and the length from said point to the tip end face is L 1 , the following equations are obtained:
• R 1 If L 1 is eliminated from the equations (1) and (2), R 1 can be obtained as shown in the folloiwng equation (3):
• the radius R n of the tapered portion of the n-th reflection point (the first reflection point from the laser receiving end ) can be expressdd by: ... (5)
• the laser beam emitted from the ordinary quartz optical fiber has a divergency angle of as narrow as 7 to 10°
• the laser beam emitted from the tip end face of the tapered portion of the rod member of the present invention can have any desired divergency angle, for example, a divergency angle of up to about 100° by adjusting the taper angle.
• the laser beam having such a wide divergency angle has an extremely high energy density in the vicinity of the tip end face of the tapered portion but the energy density is rapidly lowered as the distance from the end face increases. By this, it is enabled to effect incision of the tissue by laser beam of high. energy by contacting the tip end face with the tissue.
• the energy density of laser beam is low at the area remote from the tip end face so that mal-effect onto the tissue around the contact portion can be minimized.
• the laser probe of the present invention enables incision of extremely limited area of the tissue.
• the angle of divergency may be selected according to the purpose of laser irradiation.
• the angle of divergency is preferably selected to be 15 to 40° for coagulation and 40 to 100° for incision.
• the radius of the tip end face of the rod member may be selected within the range of from 0.01 to 1.5mm according to the kind of the operation to be conducted.
• the rod member employable for the medical and surgical laser probe of the present invention is not limited to such a configuration and a variety of other configurations may be employed.
• the modifications of the rod member of the present invention will now be described.
• a rod member 21 as illustrated in Fig.6 has a tip end face of curved surface formed for example by grinding. With this rod member 21, the laser beam emitted from the tip end face is once focused at a point near the tip end and then diffused. The so obtained high energy density near the focusing point permits effective incision of the tissue. Further, since the tip end face is formed in a curved shape, convergency of thermal stress near the tip end face is reduced as compared with the planar tip end face and heat resistance can be improved very much. In addition, since the rod member 21 has such a round end face having no angular corner, no entanglement with the tissue is caused during the incision through the contact irradiation of laser beam, and operation can be effected precisely.
• a rod member 22 as illustrated in Fig.7 has a tip end of the tapered portion which is formed of a melt 23 of an artificial saphire containing a numerous fine bubble therein.
• the laser beam propagated through the tapered portion is reflected randomly by the bubble in the melt 23 and emitted from the surface of the melt 23.
• the energy density on the surface of the melt 23 is very high and the energy density is rapidly decreased as being remoted from the surface so that effective incision of the tissue by contact irradiation of laser beam can be conducted.
• the divergency angle of the laser beam emitted from the melt 23 is so large that any desired angle of divergency can be obtained by varying the configuration of the: melt 23.
• the melt when the melt is formed in a spherical configuration having a diameter larger than the diameter of the end face of the tapered portion so as to allow emission of laser beam in the backward direction.
• the tip end portion is first subjected to local heating for example by transmitting laser beam through the rod member while keeping the tip end of the member in abutment with a ceramics material to locally heat the rod member.
• the locally heated rod member is then rapidly cooled in air.
• the configuration of the melt 23 is determined mainly by the heating time.
• Exemplary configurations for the melt 23 located on the tip end of thr tapered portion of the rod member are shown in Fig. 12-Fig. 14. It will be observed that the larger the size of melt 23, the greater the emitting angle ⁇ .
• the bubbles 23a in the melt be generally uniform in size and uniformly dispersed. Typically, the size of the bubbles will preferably be less then several microns in diameter.
• the melt have a porosity such that it appears translucent with a light transmission of about 20-50%. If the porosity is too large and the light transmission lowered, most of the laser energy will be converted to heat.
• the size of the bubbles 23a is too large, the laser beam may be reflected in undesirable directions. Finally, if the bubbles are too large, the structural strength of the melt 23 is lowered.
• the diameter of the incidence end of the tapered portion 25 is made smaller than the diameter of the columnar portion 26 for example by grinding so that the columnar portion 26b has an annular end face 27 on the end adjacent to the tapered portion 25.
• This shape of the rod member 24 provides various usage as shown in Fig. 10 by varying the point of incidence of laser beam, i.e. the distance from the quartz optical fiber 5.
• laser beam is not emitted from the annular end face 27 of the columnar portion 26 so that only the incision of the tissue 12 is carried out by laser beam emitted from the tapered portion 25.
• the distance from the optical fiber 5 is longer so as to allow laser beam to be incident all
• a rod member 28 as shown in Fig.9 has a similar configuration to that as illustrated in Figs.1 to 5 but has a diameter smaller than an outer tube 31 of an optical fiber 29 as shown in Fig.11 and has a length as short as 7mm.
• This rod member 28 is mounted on the tip end of the outer tube 31 of the optical fiber 29 and used for a biopsy channel such as endoscopicbiopsy.
• the outer tube 31 is made for example of Teflon (a trade name of polymer of tetrafluoroethylene manufactured and sold by du Pont) and is formed with an inner thread at the tip end portion thereof.
• a mounting member 32 having outer threads at the forward andrearward portions thereof is meshed with the tube 31 and the columnar portion of the rod member 28 is inserted into the mounting member 32 and a socket 33 having an inner thread on the inside thereof is meshed with the rear portion of the mounting member 32.
• the rod member 28 is mounted. With this rod member 28, hemostasis and incision through the endoscope can be carried out.
• the columnar portion 9 is formed for the purpose of fixing the rod member 2 to the holder 3 and therefore it may be omitted so that the rod member may be formed substantially in a tapered shape as a whole if an appropriate fixing means is provide
• the rod member has a tapered shape at its portion forward of the first reflection point from the incidence end of laser beam, and the configuration of its portion rearward of said point is not critical.
• the rod member may have a configuration which does not obstruct the light path of laser beam to the tapered portion.
• a brain tumor of a human being was removed by using a laser probe having a configuration as illustrated in Fig.2 in contact with the tissue.
• the rod member of the laser probe has a radius of the laser emitting end face of 0.3mm, a diameter of the columnar portion of 3mm, a length of the columnar portion of 10mm and a total length of the rod member of 50mm.
• An optical fiber is so disposed that the tip end of thefiber is spaced by 2mm from the rear face of the rod member and the angle ⁇ of divergency from the optical fiber is selected to be 8°.
• Example and Comparative Example Nd:YAG lase beam having a wave length of 1.06 ⁇ m was used and the output was 50W.
• the result shows that necrosis of 2mm in thickness was observed in Comparative Example, while the thickness of the necrosis was reduced to 0.6mm in Example of the present invention.
• damage of the tissue around the tumor was minimized in Example as compared with the method of Comparative Example.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Plasma & Fusion (AREA)
• Mechanical Engineering (AREA)
• Surgery (AREA)
• General Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Heart & Thoracic Surgery (AREA)
• Otolaryngology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Biomedical Technology (AREA)
• Electromagnetism (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Laser Surgery Devices (AREA)
• Radiation-Therapy Devices (AREA)

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• 1984
  • 1984-07-17 JP JP59502909A patent/JPH067835B2/ja not_active Expired - Fee Related
  • 1984-07-17 EP EP84902984A patent/EP0181864A1/de not_active Withdrawn
  • 1984-07-17 WO PCT/US1984/001125 patent/WO1985005262A1/en not_active Application Discontinuation
  • 1984-07-17 AU AU31567/84A patent/AU3156784A/en not_active Abandoned

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