JPH07506733A - Laser radiation transmission method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Laser radiation transmission method and device field of invention The present invention provides a device and a program for controlling the transmission of laser energy through optical fibers. Regarding Rosier.

The present invention allows sites on or within a patient's body to be placed in a ring or hollow beam shape. Particularly suitable for treatment with laser energy. Ring-shaped or hollow In the central region of the beam, little or no light energy is emitted. Actually, it doesn't exist at all.

Background of the invention Use a combination of mirrors, optical microscopes, and other equipment to view the surface of the patient's body. Artificial means of transmitting laser energy to surfaces have been developed. flexible light beam A fiber transmits laser energy into tissue or a closed space during surgery. used for. Optical fibers are inserted into arteries or other body lumens or cavities. necessitating a prescribed internal procedure via a viewing device or a surgically created passageway. It can also be advanced to the desired area. In certain medical applications, The device includes or is incorporated into a catheter and emits radiation. Transmitted to a site within the body.

Medical devices of the above type can be broadly defined as fiber transmission systems. . As used in this specification and claims, “fiber system” also refers to or “System 1” refers to the system that directs laser energy to a target site on the body surface. or a natural or surgically created internal lumen passageway or body cavity. It also broadly includes flexible or rigid devices that guide the internal target through the It is intended that

A lens can be used to transmit radiation from a laser into an optical fiber. can. For example, U.S. Patent No. 4,729,621 It has a wide proximal end that emits light and a narrow distal end that is optically coupled to the input end of the optical fiber. teaches the use of a conical coupler. The input end of the fiber is approximately Smooth and perpendicular to the optical axis of the lens or coupling system . Laser energy is transmitted from the lens into an optical fiber and then at a predetermined target. It is emitted from the tip of the fiber which is directed towards the target site.

It is inserted into the body and manipulates the laser radiation laterally to move it to surrounding sites within the body cavity. There are numerous designs for fiber stems that can be manipulated to or has been proposed. The laser energy emitted from the optical fiber is generally It impinges on the tissue in the form of a “spot,” but the tip of the optical fiber is beveled. The collision energy pattern can be changed or modified by changing the collision energy pattern. radiation Some designs use internally reflective prisms that direct the lines laterally. fiber optic By removing the cladding from a portion, the radiation is moved away from the fiber axis. It can be transmitted as approximately 3600 beams radiating toward the same direction. For example, US patent No. 4,672,961, No. 4.852,567 and No. 4.799,479 See.

Surgical laser beams are typically aimed at a spot on the target tissue. Creates an irradiation zone. For helium-neon or “HeNe” standard beams That spot is red. As a result, the tissue within the spot becomes reddish. , blood vessels within the spot can only be seen vaguely.

The above design may work satisfactorily in the specific intended application. Oriented to control ophthalmology, angioplasty, surgery, and even laser radiation sites Improved laser transmission fibers in the field of manufacturing that can also be It is desired to provide an optical system. Particularly in certain applications, annular, ring-shaped Or a target tissue with a hollow cone beam pattern - the irradiation zone In some cases, it may be desirable to apply a laser beam to generate the particles.

Annealing the inner surface of tubes, cutting materials into circular shapes, and even laser Constant closed loop of energy, e.g. ring-shaped laser energy effectively In other applications where it may be used, the above device may be relatively expensive. It would be even more convenient if it could be used in conjunction with a power laser.

Desirably, such improved devices are not bulky or overly complex.

Relatively simple and small structures can be used for catheters and other devices inserted into closed spaces. It would be advantageous if it could be used for purposes such as catheters or other devices. Probably.

Furthermore, it can also be used to irradiate sites, such as surgical sites, to remove tissue or other material at the site. An object of the present invention is to provide an improved method capable of producing a desired quality surface structure. desirable. The present invention provides a unique method to treat such sites in a controlled manner with radiation. provide

The present invention also provides a method for coupling a laser source to a predetermined beam of laser energy. Controllably direct the laser energy towards the site, e.g. a hollow cone or ring. Improved laser transmission method and optical fiber suitable for delivery in the form of Provide transmission systems. The present invention provides various device designs having the advantages and features described above. You can also incorporate in.

Summary of the invention The present invention is useful for optical fiber systems, medical devices, or laser energy systems. a hollow beam of radiant energy in a controlled manner, e.g. in pulsed or continuous wave form. carried out in industrial equipment that applies laser energy to a predetermined site as a system. I can do it. The present invention also relates to a method of applying such energy. It can be implemented.

According to one aspect of the invention, transmission along one or more optical fibers Most of the laser energy is at the tip of the optical fiber or at multiple optical fibers. The light is emitted or distributed from the tip of the fiber in a hollow cone or cylinder shape. Shape the laser energy ring in a plane approximately perpendicular to the longitudinal axis of the fiber tip. to be accomplished. By changing the inclination angle of the beam axis with respect to the entrance plane, e.g. Radiation similar to various conic sections: circular, parabolic, hyperbolic, elliptical or circular Patterns can be easily generated. Move the tip of the fibern stem Tageno! -Improve the size of the irradiation area by moving it closer or further away from the site. You can change the settings at will. In this way, the laser energy can be It can be applied to a site in a reliable and controlled manner to perform a medical procedure. Therefore, the book The invention is particularly suited for abrading the surface of the cornea to achieve the desired smooth contour.

In one preferred embodiment of the device of the invention, the optical fiber is in the form of a solid cylindrical optical fiber. , using an elongated laser energy transmission tube. The fiber extends along its longitudinal axis. It has a proximal end that extends. The beam of laser energy is directed obliquely onto the proximal face of the fiber. Collision at the corner. The proximal end of the fiber is usually at an oblique angle to the proximal longitudinal axis, preferably or oriented at an angle of 30° to 606°, more preferably at an angle of about 45°. It includes a beveled proximal surface that receives laser radiation. fibers require treatment Placed close to the site (which may be within a closed space such as a lumen or body cavity) and a distal end surface that emits laser radiation.

A focusing lens is a mounting that holds the lens and proximal end of the fiber in a specific alignment. The attachment has the means. The optical axis of the lens is approximately parallel to the proximal longitudinal axis of the fiber. or coincident, and the lens is focused onto the fiber proximal surface.

A suitable laser that emits laser energy in pulsed or continuous wave mode a laser energy source is coupled to the lens. Laser radiation passing through the lens is transmitted into the fiber, reflected along its circumference inside the fiber, and then The light is emitted from the fiber end face in a substantially hollow conical shape. Its shape is predetermined site, where it does not matter whether liquid is present or not. do not have.

One embodiment of the method of the invention is to place the tip of a cylindrical solid optical fiber over the surface of a patient. or placed opposite the target tissue within a hollow tube. Phi The proximal end of the bar has a beveled end face that receives laser radiation. The proximal longitudinal axis is arranged at an angle to the proximal longitudinal axis. Radiation is on the proximal surface The focus is focused on the beveled proximal surface via a focusing lens placed with respect to the ing. The optical axis of the lens is oriented approximately parallel to the proximal longitudinal axis; The laser radiation that passes through the fiber is transmitted into the fiber and is , and a substantially hollow conical shape of a predetermined size is reflected from the fiber tip surface. It is emitted towards the target. In this way, circular incisions as well as coagulation, ablation or insufflation are possible. is effectively done on the site.

Optical fibers also vary the size of the emitted radiation pattern by their movement. Can be decreased or increased. In addition, lasers of various energy levels delivering energy at a predetermined and/or variable distance from the target tissue for a predetermined period of time; Single or multiple tissues can be shaped or ground by Ru: In another aspect of the invention, conventional optical fibers transmit little or no transmission. Light energy at wavelengths that cannot reach the target site through bus-forming means Light energy is delivered to the laser in the form of a ring-shaped or hollow cone beam that is transmitted to the It is accompanied by a means for releasing -. The bus forming means uses a laser to direct the direction of the radiation. A microscope-like device with a mirror that changes the direction of emission from the It may also include an artificial arm. Such laser radiation is generally TEM0+beam referred to as system mode.

In yet another aspect of the invention, the radiation intensity is measured in a circumferential or angular direction on the ring. It can be changed depending on the position. Material defects, manufacturing tolerances, operating variations The intensity of the radiation at one angular position on the target ring pattern by etc. is greater or less than the intensity at another angular position on the ring. Rin Provides virtually uniform average radiation intensity over long periods of time at any location within the network. angular displacement of at least a portion of the optical fiber length with respect to its longitudinal axis There are means to do so. This is rotation or rocking in one direction or in opposite directions. can include. In one embodiment contemplated by the invention, the outer gear A small drive gear meshes with this outer gear. are doing. This small gear can rotate in one direction or in opposite directions, and its length It has an oval or elliptical shape that allows the fiber to swing around the axis in the hand direction. Good too.

The angular displacement of the optical fiber is a hollow cone or ring shaped emitted laser energy. It can be used with other fiber optic systems that generate energy. for example , at the proximal end of the optical fiber in a direction substantially perpendicular to the proximal longitudinal axis. The proximal end surface may be arranged in a manner similar to that shown in FIG. Laser radiation at the proximal end of the optical fiber It can also be introduced at an oblique angle. In that case, enter the optical fiber. The radiation impinges on the cylindrical wall of the fiber at an angle of incidence greater than the critical angle for total internal reflection. Ru. Laser radiation entering an optical fiber is transmitted to its circumferential surface inside the fiber. It is reflected along the fiber and exits from the fiber tip in a substantially hollow conical shape. Ru. The angular displacement of at least a portion of the optical fiber length is determined by the angular displacement along its radial bus. A book that may help reduce circumferential variations in the spatial radiation pattern of beams In yet another aspect of the invention, optical fibers with modified tips are used. this light The fiber has a proximal surface normal to the longitudinal axis; receives laser radiation directed toward the proximal surface. In particular, light that emits radiation The tip of the fiber is substantially conical. Preferably, the tip has a right circular conical shape. and the radiation exits in the form of a hollow beam forming a halo on the plane of incidence. be done. Again, the angular displacement of the fiber eliminates the beam-around variation in the radiation intensity. It could be used for

Another aspect of the invention involves a unique process for controlling the application of radiation to a given site. The system is intended. In particular, the laser radiation is at the tip of an optical fiber. emitted from a hollow conical radiation beam or an annular, substantially cylindrical radiation beam. Irradiate the site with the beam. The distance between the fiber tip surface and the material is determined.

The radiation intensity and duration are then automatically adjusted in accordance with the distance determination. site The material is capable of moving the fiber tip laterally and/or axially as desired. beam-ground.

The tip of the fiber can also be tilted with respect to the surface of the material, thereby A substantially circular or elliptical irradiation pattern on a material, or a conic section or its Other patterns that approximate a portion can be formed.

Another aspect of the method of the present invention is to target the tip of at least one optical fiber. the step of arranging it in close proximity to the light source. The fiber tip supports laser radiation. It has a tip surface that emits light near the light. Laser radiation is introduced into the optical fiber be done. The tip of the optical fiber is moved almost transversely to the emitted radiation, and the material is close to the surface. At least one of the following steps includes at least one other of the following steps. (1) controlling the intensity of the laser radiation; 2) The process of controlling the distance of the fiber tip from the material, (3) Injecting the laser into the material. a step of controlling the length of the period during which radiation is irradiated; and (4) a process of controlling the length of the period during which radiation is applied. The process of controlling the angle of the material to the surface.

These controlled steps can be performed on various types of optical fibers (e.g. (a) single solid (b) a single hollow optical fiber; (C) a plurality of optical fibers arranged in an annular bundle; a solid optical fiber, (d) one or more fibers having an angular end that emits radiation; or (e) a substantially uniform hollow beam or laser energy from the tip surface. A cut section of a hollow optical fiber that is long enough to obtain a ring radiation of various beam profiles from one or more optical fibers placed at its tip or with radiation delivered in a shape (e.g. solid cylinder or ring). I can do it. The laser beam emitted from the tip of the optical fiber is mechanically It can be operated as follows. The output beam can be manipulated by a mirror system, etc. You can do something like that.

Various other advantages and features of the invention can be found in the detailed description, claims, and description below. It will be readily apparent from the attached drawings.

Brief description of the drawing In the accompanying drawings that form part of the specification, the same numbers refer to the same parts throughout the specification. It is used to indicate.

Fig. 1 is a partial cross section and partial side view showing the front end of a laser transmission device embodying the present invention. It is a diagram.

FIG. 2 is a cross-sectional view taken along plane 2--2 of FIG.

Figure 3 shows a developed photographic stamp of multiple ring-shaped irradiation patterns such as the halo R shown in Figure 2. It is a reproduction of a paper image.

Figure 4 is a reproduction similar to Figure 3, but with the optical fibers arranged to form an elliptical ring shape. This figure shows the irradiation pattern that occurs when the tip of the eyebar is tilted.

FIG. 5 is a partial, schematic, and partial schematic diagram of another embodiment of an optical fiber embodying the present invention. FIG.

FIG. 6 is a schematic partial cross-sectional view of another modification of the invention.

Description of preferred embodiments The device of the invention is implemented in a racer transmission device. The transmission device is one preferred The shape of the ring-shaped putter can be used to radiate laser energy It can be applied to a predetermined body site such as the cornea of the eye while efficiently destroying damage near the site. can be minimized.

When such a device is actuated, it imparts a desired shape and shape to a body site or other target. A hollow beam of intense laser energy is applied in a controlled manner to achieve the desired ablation. , coagulation, dissection, etc., while minimizing the possibility of damage to adjacent tissue. It can be suppressed. This device is used in fields such as ophthalmology, angioplasty, urology and gynecology. Particularly suitable for applications in

The device has a wide range of applications in the surgical field, with helium neon or Irradiates low power laser energy such as HeNe laser in a ring-shaped pattern It can be configured to:

The generated hollow laser beam can be used for various manufacturing or It can also be used for industrial work.

Although this invention can be implemented in various forms, this specification and accompanying drawings are Only one particular form is disclosed as an example. However, this invention It is not intended to be limiting to the embodiments described herein. The scope of the invention is attached This is pointed out in the complaint.

The invented device can be used with any suitable conventional laser source and coupling system. can do. Although the details thereof are not shown or described here, those skilled in the art and It will be obvious to those who understand the required functionality of the equipment used. These devices are A detailed explanation thereof does not constitute an explanation or assist understanding of the present invention. Omit the description.

Referring first to FIG. 1, the apparatus of the present invention includes a laser (not fully shown). ) to focus the laser energy from the fiber onto the beveled upper proximal end of the optical fiber. It has a lot of features. The tip of the optical fiber is placed on the body surface or within a lumen or body cavity, or positioned toward the target tissue within the surgically created area or passageway. Ru. In practical terms, such fiber systems can be used in endoscopes, cameras, hollow needles, etc. , or other surgical instruments (not shown). Fa The cavity into which the Ivor System IO is inserted is a natural or surgical cavity in the body tissue. It can be a lumen, body cavity or passageway formed in the body. For example, a tissue is a body or an organ. forming a lumen or other cavity within. surgically created passageway or area is a needle, used for surgery in open or open procedures, or for laparoscopic procedures. It could be created by one location.

Typically a cavity into which a catheter is inserted or where laser energy is applied The surface tissue is a body tissue containing substances that are modified by the application of laser radiant energy. It can be characterized as forming a body. The substance is part of the tissue itself. or an altered form of tissue such as cancerous tissue. Substances are deposits that accumulate on tissues Sometimes it is a thing. For example, such deposits may include blood clots, fat, or atherosclerotic blood cells. It might be a board.

The fiber stem 10 is an optical fiber that functions as an elongated laser energy transmission tube. The fiber 20 is included. The optical fiber 20 has a converging lens and a handle (J-key) at its proximal end. coupled to a frame or assembly 22, the assembly includes a radiation laser coupled to a laser energy source 26 that generates and supplies energy to the fiber 20; tied together.

As used in this specification and claims, the term “laser energy”, “ “Laser radiation”, “laser beam” and its variants have a wide range of radiation modes and patterns. Lux or Continuous Wave (CW), as well as frequency, characteristics, and energy density or It will be understood that it includes flux.

Laser radiation is suitably produced by ordinary lasers, and only visible laser light It also includes infrared (IR) and ultraviolet (UG) radiation. generate adequate energy Examples of laser types that can be used include excimer, argon, and neodymium lasers. Tutrium aluminum garnet (Nd:YAG), frequency overlap Nd:Y AG (FTP laser), holmium, yttrium aluminum garnet (holmium/YAG) and erbium, yttrium aluminum garnet (erbium: YAG), etc. Similarly, the so-called transverse electromagnetic (TEM) model Laser energy emitted in the form of laser beams can be used. 2 TEs M. 1 mode, or TEM, a cylinder consisting of a mode and a TEM, , mote Condition TEM. , mode is particularly optimal.

Assembly 2 of the emitted laser energy using conventional means (not shown in detail) It is possible to make it incident on 2. Such means typically include a laser source 26 and an assembly. 22 has a coupling system between them. Laser source and coupling system The design, construction and operation of the system are well known in the field and are described here. Detailed explanation will be omitted. Design of such laser sources and coupling systems , details of construction and operation do not form part of the invention.

The fiber 20 has a 3° cylindrical core made of glass or silica quartz. A single, solid, elongated, integral optical fiber. In some embodiments Such fibers have a high hydroxyl content suitable for the transmission of excimer laser energy. (OH) content, or hornium: low, suitable for the transmission of YAG laser energy. It is possible that there is an OH content.

In another embodiment, zirconium fluoride, sapphire or other crystals Erbium: Yztrium Aluminum Garnet (Erbium) YAG) used to transmit radiation or other light in the infrared wavelengths can do. Alternatively, depending on the application field, fiber core 3o may be used as an example. Constructed from polymeric materials such as poly(methyl methacrylate) or polystyrene. Sometimes it happens. The diameter of the core is preferably between about 0.1 mm and about 1.0 mm. be. In one contemplated embodiment of the invention, the diameter of the core 3o is preferably The distance is within the range of about 0.3 mm to about 0.6 mm.

In a preferred embodiment, the outer cladding 34 covers the outer cylindrical surface of the core 3o. It is set up to cover. The cladding material is the refraction of the fiber core 3o. has a refractive index lower than the index. The material used for the core outer cladding 34 is The laser radiation is selected based on the refractive index relative to the core refractive index. confined within with minimal damping.

Examples of suitable latting materials include silicone, silica, glass, and plastic. There is such a thing as air or air. Plastic materials suitable for crutching include , polymethyl methacrylate or a mixture of polymethyl acrylate and polystyrene. There is a union. The thickness of the cladding 34 is, for example, approximately 0.1 mm. one project In the illustrated embodiment, the cladding 34 is air.

A variety of optical fibers suitable for specific applications are commercially available. For example, 0°4 Optical fibers with a core of diameter mm are new under the designation Med40.0. ing. Optical fiber with a diameter of 0.6 mm or under the designation HCT600, Commercially available from Ensign Bickford Company, Connecticut, USA has been done.

The power that can be transmitted along an optical fiber varies depending on the size of the fiber. become The above HCT600 optical fiber is used in a medical device implementing this invention. up to approximately 60 watts of continuous power from a Nd:YAG laser source when using can be transmitted.

protection sources (not shown), although it is not necessary for applications with ) may be provided around the outer cladding 34. The sauce is thick, for example. It can be constructed from approximately 0.2 nm of polyethylene or polyamide.

Finally, in some applications, external sources may be used instead of or in addition to sources. It may also be desirable to include a side annular cladding (not shown). Exterior material is trade name T Constructed from synthetic resin polymers such as those sold under the name EFLON. be able to. Other materials used to construct the exterior material include silicone rubber. , natural rubber, polyvinyl chloride, polyurethane, copolyester polymer, thermoplastic rubber, silicone-polycarbonate copolymer, polyethylene ethyl vinyl Some fibers such as acetate copolymers, woven polyester fibers, or combinations thereof The walls of the fibrous stem 10 may be reinforced. In addition, lead or barium salts are It can be incorporated into the wall of the tether to provide radiopacity.

Fiber 20 has a distal end 42 extending along a distal longitudinal axis 46 .

The tip of the fiber 20 has approximately a thousand planes 47 perpendicular to the axis 46, and this approximately plane - Functions to emit radiation. Substantially transparent to radiation, if desired. Clear rounded cylindrical sapphire, glass, quartz or pyrex case. It can also be fitted into a cup (not shown).

The laser radiation is focused through a focusing lens and a fiber mounted within the assembly 22. It is transmitted from the proximal end of the bar to the fiber 20. Assembly 22 includes fiber 20 An opening 68 is formed into which the proximal end is inserted. Assembly 22 is made of stainless steel It can be made from any suitable material, such as plastic or polymeric materials. fiber 2 0 by suitable frictional engagement or other fastening means, e.g. adhesive. It may also be held within the aperture 68.

The proximal end of fiber 20 is characterized as forming a proximal longitudinal axis 66. Ru. The proximal end of the fiber 20 forms a beveled proximal end surface 70, and this proximal end surface are oriented at an oblique angle with respect to the longitudinal axis 66.

A focusing lens 80 is retained within assembly 22 and is generally axially aligned with end face 70. Adjacent. To this end, the assembly 22 has an annular groove 82 in the lens 80; This annular groove 82 opens into a truncated conical passage 84 . This passage communicates with the aperture 68. in communication and axially aligned with the aperture. There is a storage on one side of the lens 80. A retaining clamp, ring, or seal 88 is provided to hold the lens 80 in position. That is desirable.

Lens 80 is bounded by two refractive surfaces oriented about a common optical axis. A suitable conventional focusing lens. The optical axis of the lens is also parallel to the fiber proximal axis 66. In fact, they match. The axis 66 and the optical axis of the lens 80 coincident with the axis 66 are at the end surface 70. On the other hand, it is characterized by being oriented at an acute angle B direction with respect to the radial plane N. cormorant.

As shown schematically in FIG. 1 by converging line 92, lens 86 Functions to focus. Radiation incident on the beveled surface 70 undergoes plane refraction and According to the well-known principles of internal reflection and total internal reflection, the outer surface of the fiber or 20 in the direction of the cladding 34 on the circumference.

In particular, the material adjacent to beveled surface 70 (between surface 70 and lens 80) or the air (or other material with a lower refractive index than the optical fiber core 30). If the angle of refraction at surface 70 in core 30 is smaller than the angle of incidence, then The radiation passing through the surface 70 is bent in the direction of the plane N perpendicular to the surface 70. .

Furthermore, in the core 30, the tarading 34 occurs at an incident angle larger than the critical angle. The impinging radiation is transmitted by multiple, total internal reflections along the length of the fiber 20. will be done. Numerical aperture (i.e., the refractive index of the material adjacent to surface 70 and the It is equal to the square root of the difference in the squares of the refractive index. This means that the light is received and the fiber 20 Determine the maximum angle that is conducted through. Of course, Kratz in Fiber 20 The skew ray of radiation impinging on the ding 34 is larger than the meridional ray. will have an angle of incidence. And the numerical aperture for skew rays is meridional larger than the numerical aperture for the rays. The acceptance angle ranges from about 30'' to about 606 Desirably, a range of 45° is close to optimal.

The use of a novel bevel shape on the fiber 20 reduces the rays of laser energy. It is possible to fire into the bar, and the key point for off-axis firing of laser energy is It can be understood that meridional angle filling of the fiber is possible. Probably.

As mentioned above, the proximal end of fiber 20, assembly 22 and lens 8o are common. while transmitting laser energy from laser source 26 to fiber 20. It functions as a connecting means. The radiation is transmitted from the fiber tip surface 47, as shown in FIG. It exits as a hollow cone, shown schematically by line 94 at . Tip longitudinal axis A virtual plane T oriented radially with respect to 46 intersects the hollow cone of side 94 and This will form a ring-shaped irradiation pattern or halo R as shown in the figure.

A radiation pattern R is placed on a body surface or within a lumen, body cavity or surgically created passageway. is used to direct a circumferential hollow beam of energy onto the tissue in front of the fiber 20. can be shot. This applies to ophthalmology, angiogenesis, urology, gynecology, etc. It is effective in medical treatment, and is also effective as a standard beam during surgical operations.

Device IO is suitable for manufacturing processes such as annealing inside the tube and circular cutting. It can also be incorporated into the equipment used.

FIG. 3 shows a number of separate hollow cone beams, such as radiation (line 94 in FIG. 1). It is a copy of an image formed on exposed photographic paper that has been subjected to a pulse of Ru. FIG. 3 shows a plurality of patterns R, each of which corresponds to the irradiation pattern shown in FIG. substantially corresponds to the curve R. Each pattern R corresponds to the optical fiber 20 shown in FIG. It was formed by aiming an optical fiber like this at a developing photographic paper. this, 4 Deebot Street, Bittsfield, New Hampshire 03263 It is sold by Kentick Corporation located in .

Laser radiation is holmium: yztrium aluminum garnet laser Therefore, it was generated. The laser has a wavelength of 2. Operated at 1 micron, 200 millimeter A problem occurred. The number of pulses transmitted into the optical fiber was 5 per second. . This optical fiber has a diameter of about 400 microns, and its proximal end faces at an angle of about 60°. forming an inclined surface (corresponding to end surface 70 in FIG. 1 where angle B is approximately 60°); When the tip of the optical fiber that emits radiation is moved and brought close to the exposed photographic paper ( (similar to moving one end of the fiber 47 to approach plane P in FIG. 1), The diameter of the ring pattern has been reduced. Finally, the pattern is discernible, irradiated, The circular central area no longer appears, and as a result, the reference character S in Figure 3 An almost solid circular irradiation pattern was displayed.

The tip of the optical fiber can be angled relative to the plane of the target site.

For example, as shown in FIG. I can do it. This creates a nearly elliptical ring shape and targets the target. Larger energy in the portion of the pattern on the light source closest to the inclined exit surface 47 Density or flux occurs.

FIG. 4 shows such an elliptical illumination pattern. Figure 4 shows the above holmium : Received laser radiation from Yztrium Aluminum Garnet Laser This is a reproduction of the above-mentioned exposed ZAPiT” brand paper.Radiation radiation of optical fiber The exit surface is inclined at an oblique angle to the plane of the photographic paper and forms an ellipse indicated by the reference letter E. A shaped ring pattern was generated.

According to another aspect of the invention, the conical beam is directed by a laser placed opposite the target. It can be ejected directly from the laser. Conical bea ejected from the tip of the fiber The direction of the beam can be changed by transmitting it through path forming means. Ru. Such means are well known in the art and include microscopes equipped with mirrors. There are similar devices or artificial arms with mirrors. This is Argon (excimer) laser, Erbium: YAG laser, CO laser - and CO! Difficult to transmit through regular optical fibers, such as lasers Especially in the case of certain lasers that emit light energy at wavelengths that are difficult or impossible to desirable.

According to the novel method of the present invention, the tip 42 of the cylindrical optical fiber 20 is attached to the body surface. Placed over or against tissue in a closed space. The tip surface is exposed to laser radiation. Oriented to be ejected near a target or site.

The proximal end of fiber 20 is arranged to extend along proximal longitudinal axis 66. , whose beveled end surface 70 is at an oblique angle to axis 66 to receive laser radiation. oriented in the direction of.

The radiation is focused onto beveled surface 70 via focusing lens 80 . lens 80 has an optical axis substantially parallel to or aligned with the proximal longitudinal axis 66 relative to the proximal surface 70 . It is placed so that it is facing the right direction. The laser radiation passes through lens 80 , and transmitted into fiber 20. The radiation is transmitted through the fiber. It is refracted and totally reflected along the circumferential surface of the bar, and finally the fiber tip surface 47 It is injected in a substantially hollow conical shape.

In a preferred form of this method, the fibers 20 are assembled into a fiber system. is advanced toward the target tissue and positioned at a predetermined axial location. The tip of the placed fiber 20 is arranged so that it can irradiate the body site.

The fiber system can be deployed visually or with the aid of fluorescence or ultrasound. You can also place Depending on the procedure, fiber systems may be used with endoscopes, cameras, etc. It may also be advanced through a needle, hollow needle, or other surgical instrument. Ru.

Use the fiber stem as an endoscope, camera, hollow needle or other surgical instrument. if inserted through a central passageway within the instrument or for that purpose within the instrument. Inject fluid around the body of the fiber system through separate channels. It's okay. Fluids include sarin solution, glycine solution, sorbitol-mannitol Cleaning fluids or treatments such as solutions, sterile water, gases (such as carbon dioxide) and oxygen-bearing liquids There is a fluid. Anticoagulants, antispasmodics, antivasoconstrictors or other active agents Or drugs can be injected together with the fluid. via an endoscope or other instrument. It can also be used for suction.

Another aspect of the invention is to create a hollow conical shape from the end of an optical fiber having a unique shape. Concerning producing radiation. FIG. 5 shows such an optical fiber 200. Fa The fiber 200 is a cylindrical, solid optical fiber with a proximal end forming a proximal surface 270. and a distal end surface 247.

Fiber 200 is the same as that described above with reference to fiber 20 shown in FIG. It can be made from one substance. In a preferred form, the fiber 20 0 proximal surface 270 is oriented approximately normal to the proximal longitudinal axis 266. facing. The tip of fiber 200 extends along tip longitudinal axis 249 Ru. Axes 266 and 249 are aligned when fiber 200 is in a linear configuration. It is above.

The distal surface 247 forms at least one generally conical shape and has a conical base. is oriented generally perpendicular to the tip longitudinal axis 249. Preferably, The tip surface 247 forms a right circular cone whose apex lies on the tip longitudinal axis 249. Ru.

The laser beam is directed at the fiber distal end face 270 and preferably emits The lines are oriented generally perpendicular to proximal surface 270. Laser radiation is is transmitted through the fiber 200 and from the conical tip surface 249 to a substantially hollow cone. Injected in shape. The exit radiation is approximately normal to the tip longitudinal axis 249. When it collides with a flat target surface, it produces a ring-shaped irradiation pattern or Form. The longitudinal axis 249 is tilted at an angle of 90° or less relative to the target plane. When the conic section or a portion thereof is similar to the conic section, another illumination pattern is generated.

Laser radiation must not be uniformly emitted from the tip of the optical fiber in a hollow conical shape. There is also. This non-uniformity may be due to manufacturing and/or assembly tolerances, material properties or This may be due to slight variations in composition, slight variations in operating conditions, etc. Therefore, the target The radial pattern (as shown in Fig. 2) in the ring-shaped pattern R formed on the The strength or flux of the field is angular or circumferential on the ring pattern. It will be non-uniform with respect to the position in the direction. For example, referring to Figure 2, /% low putter The annular portion or segment Zl of the ring pattern R is larger than the remaining portion of the ring pattern R. In other annular parts, the radiation intensity or flux is different from that of the ring pattern R. It will be different from that in the part.

Applications requiring many and tight manufacturing, assembly and operating tolerances , such variations have a negligible effect on specific uses of radiation. It's just that they have it. However, the general power level, ring pattern Depending on size and other factors, angular variations in ring pattern strength may occur. be sufficiently pronounced that it may cause damage to tissue at the target site or to other target materials. This will have an undesirable uneven or non-uniform effect. For this reason, the angular direction Provide measures to reduce (circumferential) fluctuations, if not eliminate them. That would be desirable.

Furthermore, if central zone ablation is required, the closest fiber This may cause splashing of removal byproducts and contamination or damage to the fiber tip. move the fiber very close to the target tissue to create a solid or complete Rather than forming a full spot, the energy gradually decreases laterally. It would be desirable to be able to draw the central spot of the eel.

This provides a nearly uniform illumination pattern over a period of time in the center or at the periphery. A new system can be used that allows for When identified, Figure 6 shows As shown, at least the length of the optical fiber, e.g. A portion of the fiber 300 is rotated about its longitudinal axis while the radiation is being emitted from the fiber 300. angularly displaced. The fiber 300 is a fiber as described above with reference to FIG. It may have the same composition as fiber 20. Fiber 300 is the fiber of FIG. proximal end shape and shape as shown for fiber 20 or fiber 200 in FIG. It may also have a tip shape. In either case, the fiber 300 is Works with a radiation source to emit a substantially hollow cone of laser radiation from the fiber tip. It is arranged so that it comes out.

The driven ring gear 350 is attached to the fiber by suitable means (e.g. 353 adhesive). It is attached to the peripheral surface of 300. Drive gear 355 meshes with ring gear 350 are doing. Drive gear 355 is mounted on shaft 357. shaft 357 is driven by a suitable means such as a motor (not shown), and the driving gear 35 Rotate 5. When the drive gear 355 rotates, the ring gear 350 also rotates, and The fiber 300 is rotated about its longitudinal axis. rotation is a small angle It would be a degree displacement. In the preferred form, this angular displacement of fiber 300 oscillates (as indicated by phase direction arrow 359) and causes drive gear 355 to oscillate. caused by the motor to move (in the direction of phase direction arrow 360). here In the intended operating configuration, the fiber 300 extends from about θ° to about 360°. It will oscillate between. Furthermore, the laser radiation source is operated in pulsed mode If so, the rocking is preferably synchronized with the laser energy pulse. this can be performed using a suitable multi-stage motor and control system 361. I can do it. Control system includes ring gear 350, gear 355 and shaft 357 in a suitable conduit or encapsulant 363 that isolates it from the surrounding environment. including one or more suitable switches attached thereto. Part of the length of optical fiber 300 Typically, only the tip of the fiber 300 is illuminated. During the injection process, the tip is oscillated or angularly displaced about the longitudinal axis of the tip. It will be done.

In ophthalmology, corneal abrasion or modification involves applying laser energy of a predetermined intensity to the cornea. This can be accomplished by injecting it from a certain distance from the membrane for a certain period of time. Wear. Temporary retraction of the corneal epithelium prior to laser irradiation of the anterior surface of the cornea In some cases, this may be desirable. radiation energy level, distance from the cornea, and/or By changing the duration of laser irradiation, the rate and rate of ablation, vaporization, or coagulation can be increased. and the size and depth of the illuminated area can be changed. For the Habo plane site By tilting the angle of the fiber tip from its vertical position, the laser beam can be The energy can be ejected in an elliptical or parabolic shape, for example. that kind of shape relatively greater energy density and deeper depth at one end of the shape than at the other end. causes ablation, vaporization or coagulation, creating a bifocal effect.

The tip of the optical fiber or catheter is manually or mechanically, preferably controlled. Mechanical means that allow more precise control of the grinding process with pewter instructions This makes it possible to move the emitted radiation substantially laterally. excision Or the depth of coagulation can be determined by displaying the patient's corneal shape on a television monitor. You can also use the light ben to draw the desired pattern on the screen. You can also do that. This occurs in one or more planes, preferably at least two planes. laser energy, exposure duration, distance from the cornea and location. The desired applied energy can be determined. Trial run the computer for safety purposes The final shape of the cornea can then be displayed for comparison with the initial shape.

These operations can be used, for example, to increase or decrease the curvature of the cornea. Can be done. You can also use these techniques to simply heat the site and cross-link the collagen. causes localized contraction of the corneal surface into a ring shape or other desired shape. You can also rub it.

The curvature of the cornea, and thus the refractive properties of the eye, can be modified by selective removal of corneal tissue and/or corneal tissue. can be adjusted by selective denaturation of Removal of corneal tissue according to the invention This can be done in a controlled manner using hollow beam irradiation in the ultraviolet or infrared region. on the other hand , thermal degeneration of a predetermined area of corneal tissue is performed using laser beam irradiation in the near-infrared region. I can do it.

In the type of laser transmission device of the invention that produces a hollow beam, the Shimmer or Erbium:YAG laser controlled by computer X-, Y-.

Cornea by coupling with the Z-uniplane positioning system and changing its outer contour. can be used to change the refractive power of the

Similarly, appropriately pulsed and/or frequency tripled (351 μm wavelength) N d: Computer control of YAG, holmium, erbium, etc. thermal lasers Appropriately connect with the X-, Y-, Z uniplanar arrangement system to inject heat-denatured collagen into the cornea. altering the refractive power of the cornea by creating three-dimensional zones or regions of I can do it. These three-dimensional zones or regions modify the outer contour of the cornea and thus There can be any desired shape that changes its optical power. Use the above techniques alone or Or, if used in combination, desired corneal abrasion can be achieved.

In addition, when corneal abrasion is performed using thermal techniques, the cornea is It can also be pretreated with an envelope that preferentially absorbs wavelengths. For example, riboflavin Dye or the patient's own red blood cells are applied to the cornea and used with an argon laser be able to.

Laser energy can be transmitted in pulsed mode as well as continuous mode if required can do. Laser beam ranging from approximately 0.15 μm to approximately 11 μm Depending on the wavelength of the horn, thermal denaturation or decomposition as well as photolytic ablation can be carried out. The power flux applied during membrane grinding may be pulsed or continuous, and may be square or Approximately 1 joule per senna meter to approximately 1 joule per square centimeter within the range of

When irradiating with a pulsed mode laser beam, the energy of each individual pulse is transmitted. Usually it can be varied from about 1 millijoule to about 300 millijoules. Ru. Pulse durations range from about 10 nanoseconds to about 400 microseconds. Pal The depth of corneal ablation per scan is approximately 0. In the range of 1 micron to approximately 200 microns be. The excimer laser power flux of ljou le/cm” is The membranous tissue is excised to a depth of approximately 1 micron.

The distance between the optical fiber tip and the material at the irradiated site can be determined using the infrared distance determination method, It can be measured using sonar ranging or other methods. of distance by inputting the measurements into a suitable microprocessor or computer. the energy intensity of the laser radiation, the duration of exposure of the site material to the radiation, and/or or the position of the fiber tip relative to the site.

The above control method is used not only for ophthalmological work, but also for laser radiation during medical and non-medical work. It can be applied to optical fiber transmission. This control method uses a ring-shaped pattern. The above solid optical fiber generates a hollow cone beam that illuminates the target site with a need not be limited to use with ibar. In fact, the above control method Laser radiation in the form of an almost solid cylindrical beam that forms a spot zone at the site It can also be used with optical fibers that emit .

In another aspect of the method of the invention, a plurality of solid optical fibers (e.g. from about 200 to about 500 having a diameter ranging from about 10 microns to about 50 microns fibers) are arranged in an annular bundle. This connects the fibers to a pair of identical This is obtained by filling the annular space between the core and the cylindrical sleeve. This structure The structure can be used to transmit a generally ring-shaped beam.

In addition, a solid optical fiber extending from the laser at the proximal end of a sufficiently long hollow optical fiber is When laser radiation from the bar is supplied, a ring-shaped Radiation is emitted in the form of a beam.

Whether it is a fiber ring bundle or a single hollow optical fiber, the tip is the target. Tilted or forming an angle with respect to the material surface of the site. For this reason A roughly elliptical ring-shaped target area is provided where the energy intensity is It varies depending on the predetermined position within the oval ring pattern.

Similarly, solid optical fibers are tilted relative to the target site and are oval pattern on the site.

The radiation exit tip of the above-mentioned fiber annular bundle can be placed at the angular or beveled end. can be done. Similarly, the ends of hollow optical fibers can also be cut into angular or beveled ends. A bell-shaped end can be formed. The surface of such a beveled end is When viewed from the normal direction to the hand direction axis, it appears to be elliptical or oblong.

The present invention provides a novel method and apparatus for efficiently controlling and directing radiation. , the radiation is transmitted to a predetermined site located in a closed space in the form of a hollow cone or ring. It will be understood that this includes sending.

By following the above method, a practitioner in the field of medical device use and manufacturing will be able to realize the benefits of the present invention. Further applications and modifications may easily come to mind. Therefore, the present invention and the specific implementation used to teach the invention. It should not be construed solely according to the embodiments.

FIG.5 Continuation of front page (51) Int, C1, 6 identification code Office reference number HOI S 3/101 8832-4M (72) Inventor Harasan Honey M.G.A. Country, 92626 California, Costa Mesa, Partola, 2001I

Claims (1)

[Claims] (1) Devices that emit laser radiation as a hollow beam, which are as follows: Consisting of; a cylindrical optical fiber having a proximal end extending along a proximal longitudinal axis; The proximal end of the bar is oriented to form an oblique angle with respect to the proximal longitudinal axis. The fiber includes a beveled proximal end surface onto which the laser beam is incident; and an end face that emits the laser beam. do A convergent lens, and the lens and the proximal end are held in the following arrangement. mounting means, (A) the optical axis of the lens is (1) substantially parallel to the proximal longitudinal axis; (2) the longitudinal axis; (B) the lens is arranged in any direction and position; and (B) the lens - The laser beam passing through the lens is aligned with the end point almost on the proximal surface, and the laser beam passes through the lens. transmitted into the fiber and reflected along the circumference within said fiber, forming a substantially hollow cone. It is emitted as a body-shaped beam. (2) The device according to claim 1, wherein the fiber is fluorinated zirconium Composed of Erbium: Yttrium Aluminum Garnet Transmits laser light from a laser. (3) The device according to claim 1, wherein the fiber tip is arranged in the longitudinal direction of the tip. extending along an adaxial axis, and the fiber distal surface is relative to the longitudinal axis of the distal end. The laser beam is oriented almost perpendicularly to the fiber end face. It is injected in a substantially hollow conical shape. (4) The device according to claim 1, wherein the optical fiber has a solid elongated shape. have (5) The device according to claim 1, wherein the lens optical axis is in the proximal longitudinal direction. coincides with the axis. (6) The device according to claim 1, wherein the device comprises: The light beam is reflected on the end surface to change the direction of the light beam relative to the direction of emission from the tip surface. forming at least one light beam transfer bus including at least one lens to be varied; The device further includes a bus forming means. (7) The device according to claim 1, wherein the device comprises: a drive hand capable of angularly displacing at least a portion of the tip with respect to the longitudinal axis; It further has a step. (8) The device according to claim 7, wherein the driving means means for swinging the distal end of the longitudinal axis about the longitudinal axis. (9) The device according to claim 8, wherein the swinging means a driven ring gear attached to the peripheral surface; a drive gear meshing with the ring gear; a shaft connected to a drive gear; and means for rocking the shaft. (10) A device for irradiating a site with laser radiation in the form of a hollow beam, , consisting of; a cylindrical shape having a tip disposed proximate to the site and emitting the laser radiation; optical fiber; and integrated into the fiber to direct the radiation from the laser to the fiber. coupling means for transmitting to the proximal end, said coupling means comprising: (a) a frame; ( b) held at an inclined angle with respect to a predetermined coupling axis by said frame; (c) a proximal end of the fiber having a beveled proximal end surface; and (c) a proximal end of the fiber having a beveled proximal end surface; a convergent lens held by a converging member, the optical axis of which is substantially parallel to the pulling axis; (2) either aligned with the coupling axis; the lens is held by the frame so as to maintain the It is continuously held by the frame so that it is focused on the bell-shaped proximal end surface, and the Laser light passing through the lens is transmitted into the fiber and is reflected along the circumferential surface of the fiber, and a substantially hollow cone-shaped beam is reflected from the tip surface of the fiber. It is emitted as a beam. (11) The device according to claim 10, wherein the fiber tip has a tip length extending along a manual axis, and wherein the fiber distal surface is aligned with the distal longitudinal axis. The radiation is oriented substantially perpendicularly to the fiber tip surface. The beam is emitted from the beam in the form of a substantially hollow cone. (12) The device according to claim 10, wherein the fiber is Composed of Erbium; Yttrium Aluminum Garnet Transmits laser light from a laser. (13) A device that generates a hollow conic-shaped laser irradiation pattern on the site. It consists of the following; a cylindrical, solid optical fiber having a proximal end extending along a proximal longitudinal axis; The proximal end of the fiber receives laser radiation in a direction substantially perpendicular to the proximal surface. a proximal end surface that is light, the fiber extending along a distal longitudinal axis; a tip disposed close to the laser beam and a tip surface that emits the laser radiation; and the tip surface has a conical bead oriented substantially perpendicular to the longitudinal axis of the tip. at least one generally conically shaped portion forming a The laser radiation incident into the fiber forms a substantially hollow cone from the fiber tip surface. It is emitted in the shape. (14) The device according to claim 13, wherein the proximal end surface is in the longitudinal direction of the proximal end. The apex of the tip surface is oriented substantially normal to the axis, and the apex of the tip surface is aligned with the tip. The end forms a right circular conical shape located on the longitudinal axis. (15) Current pattern laser emission with substantially uniform, angular, time-average intensity at the site a device for irradiating said laser radiation, comprising: a cylindrical optical fiber having a proximal end including a proximal face for receiving light; a tip disposed close to the site and a tip surface that emits the laser radiation; Ru; a laser light source for transmitting the laser radiation from the proximal face into the fiber; means, the light source means and the fiber cooperate to direct the laser light to the fiber tip. exits from the surface in a substantially hollow conical shape; and at least the fiber length is A driving means for angularly displacing a portion of a part about a longitudinal axis. (16) The device according to claim 15, wherein the driving means is arranged in a longitudinal direction thereof. and means for oscillating the fiber length about an axis. (17) The device according to claim 16, wherein the swinging means a driven ring gear attached to the circumferential surface of the ring gear; a driving gear that meshes with the ring gear; ; a shaft connected to the drive gear; and means for rocking the shaft. nothing. (18) Laser radiation is irradiated as a hollow beam to create a ring-shaped pattern on the site. A method of generating Consists of the following steps; (a) the distal end of the cylindrical optical fiber is arranged with respect to the site, and the tip of the distal end is emitting said laser radiation from an end face into the vicinity of a site; (b) a base of said fiber; the end portion extending along the proximal longitudinal axis such that the beveled proximal surface of the portion the laser radiation oriented at an oblique angle to the proximal longitudinal axis; Receive light; (c) By a converging lens arranged with respect to the proximal end surface in the following positional relationship: , the optical axis of the lens focusing the radiation onto the beveled proximal surface is (1) (2) substantially parallel to said proximal longitudinal axis; (2) either aligned with said longitudinal axis; The laser beam that passes through the lens is transmitted into the fiber and is reflected along the circumferential surface within the fiber, and is substantially hollow from the tip surface of the fiber. It is emitted in a conical shape. (19) The method according to claim 18, wherein step (a) comprises orienting the end surface substantially perpendicular to the longitudinal axis of the tip. , whereby the radiation emerges from the fiber tip surface in a substantially hollow conical shape. shot. (20) The method according to claim 18, wherein in step (c), the optical axis of the lens is positioning the lens in alignment with the proximal longitudinal axis. (21) The method according to claim 18, wherein step (a) comprises bending the core by bending the core. arranging said fiber surrounded by a cladding having a refractive index lower than step (b), the proximal end portion having the bevel-shaped proximal end surface is Place it close to a medium that has a refractive index lower than that of the ivercore. and in steps (b) and (c), the plane perpendicular to the beveled proximal end surface is end oriented at an acute angle with respect to a longitudinal axis, and (1) the refractive index of the medium and (2) the acute angle The product of the sine of power (SINE) is (1) the square of the refractive index of the fiber core and (2) the above so that it is smaller than the square root of the difference in the squares of the refractive index of the fiber cladding. including positioning the fiber proximal end. (22) The method according to claim 18, wherein the method grinds a tissue such as a cornea. (SCULPT) and includes at least one of the following steps; (1) a step of varying the laser radiation intensity, (2) the fiber tip surface and the a step of varying the distance between the tissues; (3) A step of varying the laser radiation emission time. (23) A method of irradiating materials at a site with laser radiation, which comprises the following steps: Become: (a) The laser radiation is emitted from the tip of the optical fiber, and the laser radiation is emitted in a hollow conical shape. irradiating said site in the form of either a beam or an annular cylindrical radiation beam; and hand, (b) before grinding the substance with the beam by moving the fiber tip; determining a distance between the fiber tip surface and the substance and responding to the distance determination; Then, the process of adjusting the radiation intensity and radiation time is performed. (24) The method according to claim 23, in which the fiber tip is moved. The step is to tilt the fiber tip with respect to the surface of the material and to place the fiber tip on the material. The method includes forming a nearly annular elliptical illumination pattern. (25) A method of irradiating materials at a site with laser radiation, comprising the following steps: Become: (a) disposing the tip of at least one optical fiber with respect to said site; Laser radiation is emitted from the tip surface of the tip of the fiber to the vicinity of the site. so that (b) injecting said laser radiation into said optical fiber; and (c) said The tip of the optical fiber, which is close to the material surface of the site, is placed approximately horizontally to the emitted light. direction, and perform at least one of the following steps at least one of the following steps: in response to at least one other step: (1) controlling the laser radiation intensity; (2) controlling the distance of the fiber tip surface from the substance; (3) controlling the distance of the substance; (4) controlling the exposure time to the laser light; and (4) controlling the exposure time of the fiber tip surface to the laser light. Control the angle relative to the material surface. (26) The method according to claim 25, wherein step (b) comprises using an infrared distance measurement method. and sonar ranging using one method selected from the group consisting of including measuring distance. (27) The method according to claim 25, further comprising the following steps: displaying the actual shape of at least one planar cross section of on a video monitor; Write the desired surface shape of the one planar cross-sectional view with a light pen; By controlling the movement of the tip by computer and scanning the laser irradiation as desired. Perform step (c). (28) The method according to claim 25, wherein step (a) comprises a beveled tip surface. A large number of hollow optical fibers are oriented in an annular bundle structure, and the hollow optical fibers are The tip of the blade is placed near the site, and the beveled end surface is placed near the site. orienting the material at an angle to the surface of the material. (29) The method according to claim 25, wherein step (a) comprises A single hollow optical fiber is oriented at an angle to the material surface of the site. including placing the (30) A method of shaping the cornea (SHAPE), the method comprising: from about 0.15 μm to about Generate a hollow beam of laser energy with a wavelength in the range of 11 μm; do, At least a portion of the generated hollow beam is applied to a predetermined region of the cornea to determine the refractive properties of the angle antinode. It consists of irradiating said area for a sufficient length of time to make the change.