1 COAXIAL ILLUMINATED LASER ENDOSCOPIC PROBE AND ACTIVE 2 NUMERICAL APERTURE CONTROL 3 4 This application claims priority of U.S. Provisional Patent Applications #60/490,399 filed 57/28/2003, and #60/550,979 filed 3/05/2004, and #60/xxx,xxx entitled Medical Light intensity 6Phototoxicity Control Card fύeά 6/05/04, and #60/xxx,xxx entitled Photon Lllumination and 7 Laser Ferrule filed 6/05/04. (application numbers for the latter two provisional applications are 8 not presently assigned, this application will be amended upon receipt of the application numbers) 9
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11 BACKGROUND OF THE INVENTION
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13 The art of the present invention relates to fiberoptic endoscopic probes for vitreoretinal
14 surgery in general and more particularly to an apparatus and method for delivery of both broad
15 spectrum illumination and coherent laser treatment pulses through a common optical fiber. The
1 βpresent invention also provides surgical illumination intensity control by providing an apparatus 17 and method for quickly and easily providing a fiber optic illumination light output intensity 18 reference to ophthalmic surgeons. The present invention also utilizes a unique fiber optic 19connector ferrule which uniquely indicates to the aforesaid apparatus source whether the fiber
2 Ois designed, best suited, or desired for illumination or laser transmission light or both. Also 21 integral to the present invention is an optical power meter, preferably for measurement of laser 22 output power emanating from the optical fiber.
23 Prior art vitreoretinal surgical procedure utilizes discrete and separate optical fibers for
24 the delivery of typically non-coherent light for illumination and coherent laser beam light for 25surgical treatment of tissues. Although prior art "illuminated laser probes" of various 2 βconfigurations have been developed, they all utilize separate optical fiber or fibers for the non- 27 coherent illumination stream and the coherent laser delivery. The aforesaid fibers are typically 28 arranged side by side inside of a common needle lumen. An embodiment of this prior art
29teclιnology is found in U.S. Patent # 5,323,766, issued to Uram. This prior art technology
3 Orequires a larger or more than one incision in order to introduce illumination and laser treatment 3 llight into the eye or other structure, thereby generating greater trauma to the surgical site.
32 Prior art devices typically utilize a laser deliver core optical fiber diameter of typically
33200 to 300 microns since said diameter provides the surgical laser burn spot size most commonly 34 desired by the surgeon. The aforesaid prior art devices have been unable to provide sufficient 35 surgically useful illumination (non-coherent white light) power through such a small fiber,
1 primarily due to the prior art's inability to focus said non-coherent surgically useful light onto such a small spot size. Moreover, none of the prior art devices have combined the aforesaid surgically useful illumination and laser treatment light and transmitted through a single fiber,
4 especially of the aforesaid small size. The present art apparatus and method provides coaxial delivery of both broad spectrum illumination and coherent laser treatment pulses through
6 a common optical fiber. In a preferred embodiment, the apparatus first comprises a non-coherent light source (coherent in an alternative embodiment) capable of coupling sufficient illumination
8 light into an optical fiber with a core diameter suitable for vitreoretinal laser treatment light
9 delivery. That is, to provide a volume of light to the surgical site which is sufficient for 0 illumination of the surgical procedure. In a preferred embodiment said core fiber diameter is Itypically 200 to 300 microns since said diameter provides the surgical laser burn spot size most 2 commonly desired by the surgeon. The aforesaid optical fiber is typically a multi-mode stepped 3index fiber in a preferred embodiment. Alternative embodiments may vary the type and size of 4the optical fiber without departing from the scope of the present art. An obj ect of the5present invention is to utilize a light source capable of using 250 micron (or smaller) optical βfibers while still providing similar surgically useful lumen output to current 750 micron fiber7sources (typically 10-12 lumens). The source output aperture of the present invention in a δpreferred embodiment is at least 0.5 na (numerical aperture). Alternative embodiments may vary 9this numerical aperture without departing from the scope of the present invention. The color of Othe light delivered by the present invention appears white despite the light power output or1intensity. Also, the output intensity is capable of reduction without significantly affecting the 2 color, aperture, or homogeneity of the light. The output bandwidth of the aforesaid light is 3substantially limited to the visible spectrum, that is both UN and IR light are minimized. An 4 option for user selectable limitations (separate from the UV and IR limitations) in the output 5 spectrum is provided. Apparatus conformance to relevant safety standards is also provided. 6 Prior art illumination light sources typically require a minimum aggregate optical fiber 7 core area equivalent to a fiber diameter of approximately 500 microns in order to deliver 8 sufficient illuminating light to be considered useful by the surgeon. A fundamental prior art 9limitation with utilization of smaller light fibers for illumination is the size of the focus spot in Othe light source itself. In a preferred embodiment, the art of the present invention utilizes a small lgeometry arc lamp which is capable of focusing to an extremely small illumination spot size due
Ito its extremely small plasma ball. This focusing attribute allows for efficient coupling of
2 illumination light into an optical fiber of 100 to 300 micron core diameter which is typically
3 utilized for laser treatment light delivery. Utilization of the aforesaid preferred embodiment
4 allows for up to 40 milliwatts of illumination light to be delivered by a fiber previously
5 considered too small to be an efficient illumination light source. The aforesaid present art light
6 source includes an input aperture or connector for the attachment of a laser coupling fiber. The
7 aforesaid aperture attachment is somewhat similar to the method by which a treatment laser is
8 attached with an ophthalmic slit lamp. That is, via a fiber optic pigtail typically equipped with
9 a mechanical output connector such as an exi sma. In the preferred embodiment, dichroic optics Oand/or other optical path design techniques are used to coaxially couple a treatment laser beam linto the illumination optical path, and into an endoscopic probe optical fiber. That is, with the2aforesaid coupling arrangement (using a single fiber), the present art apparatus and method3 allows a unique single and smaller optical fiber to be utilized for both illumination and laser 4treatment purposes. The art of the present invention further provides a new generation of vitreo-5retinal endoscopic instrumentation which utilizes the prior art space occupied by larger 6 illumination fibers and is also capable of providing such in a smaller cross-sectional fiber bundle. 7 The present art accepts laser light from various surgical laser sources, mixes said laser8 light with illumination light, and launches both down a single fiber. Laser output aperture is 9minimized and the laser light is not substantially affected by the illumination dimming o other 0 spectral output limiting. An aiming beam is visible within the illumination output pattern. lUnique to the present art is a shadow appearance in the output light cone which indicates the 2 location of laser treatment upon activation of a laser light source. Power losses through the 3 system are also minimized. As aforesaid, the laser mixing method does not significantly affect 4illumination when not in use (i.e. color, aperture, or homogeneity). 5 Another unique feature of the present art invention is the ability to change the angular βlight output from an endoscopic probe coupled with the aforesaid coaxial optical fiber by actively 7 controlling the focus characteristics of the light source. That is, prior art light sources have a 8 fixed numerical aperture focus configuration which is typically designed to fill the full 9 acceptance cone of the mating optical illumination fiber. The present art invention further Ocomprises and utilizes surgeon controlled condensing optics to provide a variable focused light loutput from the endoscopic probe and efficient coupling into different fiber types. This is
1 especially useful for coupling with optical fibers having different numerical aperture 2 requirements. 3 Ophthalmic surgical illumination devices for use with optical fibers are found in the prior 4 art and have been manufactured by numerous companies for years. One of many such devices 5 is described in U.S. Patent #4,757,426 issued to Scheller, et al. on July 12, 1988, Entitled <o" Illumination System for Fiber Optic Lighting Instruments". One of the most widely used 7 illumination devices is the "Millennium" which is manufactured by Bausch and Lomb®. Other 8 manufacturers are Alcon® with the "Accurus" and Grieshaber® with the "GLS 150". Due to the 9 prevalence of the aforesaid within the marketplace, it is desirable for new and high intensity 10 illumination devices, such as the present art device, to provide an intensity reference indication llto ophthalmic surgeons which allows them to reliably duplicate or mimic the illumination 12 intensity of one or more of the aforesaid prior art devices. This is especially true since retinal 13photic injury is a possible complication of the need to use bright light to clearly visualize ocular 14 structures during delicate ophthalmic surgical procedures. The present art invention further 15represents a novel apparatus and method for providing the ophthalmic surgeon with graphical
1 βphotoxicity risk information in a clear and easy to understand manner. In a preferred
17 embodiment, it is comprised of an inexpensive card that is removably attached to the control
18 panel of a surgical light source in order to show the relationship between the output intensity of 19the light source and the likelihood of photic injury.
20 Further included with the present art apparatus is an integral optical power meter which 2 lis in a preferred embodiment, capable of measuring the laser power output emanating from the 22fiber optic. Alternative embodiments of said laser power meter also measure the illumination 23power intensity.
24 Accordingly, it is an obj ect of the present invention to provide a coaxial illuminated laser
25endoscopic probe and active numerical aperture control apparatus and method of use which is 2 βcapable of transmitting both illumination (non-coherent) and laser (coherent) treatment light 27through a single optical fiber of sufficiently small diameter that said fiber may be used for laser 2 δtreatment, especially in eye surgical or ophthalmic applications.
29 Another object of the present invention is to provide a coaxial illuminated laser
30 endoscopic probe and active numerical aperture control apparatus and method of use which 31provides both a surgically useful illumination (non-coherent) output and a combined laser
(coherent) output. Another object of the present invention is to provide a coaxial illuminated laser endoscopic probe and active numerical aperture control apparatus and method of use with an
4 illumination intensity control which is usable by the surgeon to control illumination intensity without affecting laser output power or laser beam spot size characteristics or illumination
6 spectral content. A further object of the present invention is to provide a coaxial illuminated laser
8 endoscopic probe and active numerical aperture control apparatus and method of use which
9 connects with conventional laser light sources.0 A further object of the present invention is to provide a coaxial illuminated laser lendoscopic probe and active numerical aperture control apparatus and method of use which2 provides a shadow or aiming hole within the illumination light cone projection where the laser 3treatment is placed.4 A still further object of the present invention is to provide a coaxial illuminated laser 5endoscopic probe and active numerical aperture control apparatus and method of use which βprovides an intensity reference indication to ophthalmic surgeons which allows them to reliably 7 duplicate or mimic the illumination intensity of one or more prior art devices or allows them to δunderstand and minimize phototoxicity risks relating to the illumination output.9 A still further object of the present invention is to provide a coaxial illuminated laser Oendoscopic probe and active numerical aperture control apparatus and method of use which Iprovides a unique ferrule or connector for optical fiber connection which uniquely indicates to 2the aforesaid apparatus source whether the optical fiber is designed, best suited, or desired for 3illumination or laser transmission light or both.4 A yet further object of the present invention is to provide a coaxial illuminated laser 5endoscopic probe and active numerical aperture control apparatus and method of use which βminimizes trauma to the patient and surgical site.7 A yet further object of the present invention is to provide a coaxial illuminated laser 8 endoscopic probe and active numerical aperture control apparatus and method of use which has 9an integral power meter for measurement of laser output power.0 1 SUMMARY OF THE INVENTION
1 To accomplish the foregoing and other obj ects of this invention there is provided a device
2 for providing non-coherent illumination light and coherent laser treatment light through a single
3 optical fiber of the size typically used for laser treatment only. The apparatus is especially suited
4 for use during ophthalmic surgery.
5 The present art, in a preferred embodiment, utilizes a 75 watt xenon arc lamp for its high
6 luminance illumination (light density), greater than 6000 °K color temperature, and greater than
795 color rendering index. The xenon arc lamp further provides an extremely small point light
8 source which allows for a smaller output illumination beam diameter. Unique to the present
9 lamp source is a mount which allows for replacement of the lamp and yet retains the location of Othe plasma ball of said source precisely at a predetermined location within the optical center of lthe apparatus.2 A classic spherical reflector and two lens light collection layout is utilized rather than3other lower part count layouts, such as using an elliptical reflector or a combination of a 4parabolic reflector and lens. Light that is incident on the reflector is reflected back to the lamp. 5A first achromatic lens collimates light from the source and the upside down or inverted image. 6 A second achromatic lens is located coaxial to the first lens and focuses the light at its focal 7 point. The optical fiber is located at the focal point of the second lens. The aforesaid reflectors8 are preferably spherical rather than parabolic in order to reflect illumination light in the same9form as sourced from the arc lamp.0 An additional separate illumination path is possible with the present art. No other lconventional illumination light source incorporates multiple light paths from a single lamp. The 2independent nature of the two paths allow different filtering and intensity control settings to the 3two outputs. 4 Output dimming of the present art illumination is accomplished by steering the first 5(collimating) or penultimate lens in a fashion that does not change the lens numerical aperture 6or introduce shadow artifacts into the beam. A control lcnob allows the user to select the desired 7 illumination level by rotating the knob.8 The output optical fiber connector is uniquely configured to provide the precise 9positioning required while reducing cost. A precise connector end is combined with an integral Oretention thread to reduce parts cost and assembly time. An optional groove or recess is placed Ion a second version of the connector to provide for sensing the difference between illumination
1 only and laser compatible output fibers. Placement of a smooth diameter connector into the output activates a switch which will allow the laser power to be mixed. Either the lack of a connector or the groove under the switch will cause the switch to not activate and the laser power
4 will not be mixed in. Regarding mixing of laser treatment energy or light, laser light is delivered to the system
6 via a preferably 50 micron optical fiber or equivalent. Laser light exiting the delivery fiber is preferably collimated using a 16 mm focal length achromatic lens or equivalent. If all safety
8 requirements are met (i.e. laser output compatible fiber inserted and selection switch for laser
9 output activated) a steering mirror reflects the collimated laser light into the center of the Oillumination axis. This results in the output of the fiber having a cone of white light with a 1 shadow in the center nearly filled with the laser aiming beam (treatment beam during treatment).2 That is, the laser provides an aiming beam, typically red, when not fully activated for treatment 3and a treatment beam, typically green, when fully activated. Without the shadow caused by the4 steering mirror the aiming beam would be entirely washed out or imperceptible except at very 5low illumination levels.6 As described, unique to the present art is a coaxial laser and illumination apparatus which7 heretofore has not be available or utilized. Also unique to the present art is a highly efficient8 illumination system which utilizes spherical reflectors and associated lenses to capture a 9maximum light output and also provide a twin path illumination light output from a single lamp 0 source in order to feed fibers of diameter less than 500 microns which are conventionally used lfor laser treatment only. Further unique to the present art is a laser steering mirror having a 2 solenoid selectability which provides an aiming hole within the illumination path for laser 3placement. Still further unique to the present art is an illumination arc lamp system having an 4 extremely small point light source which allows for an extremely small illumination focus size 5or numerical aperture output. Also unique to the present art is an arc lamp mount which precisely βplaces the plasma ball of the arc lamp at the focus center of the optics system. Also unique to 7the present art is a unique dimming mechanism which moves the focal point of a dimming lens 8 in order to provide dimming without introducing artifacts, cliromatic aberrations, or changes of 9color temperature. Also unique to the present art is a capability of connection with existing 0 conventional laser light sources whereby laser treatment and illumination are both provided at Ian output of the present art apparatus.
The present art invention also represents a novel apparatus and method for providing the ophthalmic surgeon with graphical photoxicity risk information in a clear and easy to understand
3 manner. In a preferred embodiment, an inexpensive card is removably attached to the control
4 panel of the surgical light source. Preferably, the present art card is attached in close proximity
5 to the light intensity control in order to show the relationship between the output intensity of the
6 light source and the likelihood of photic injury. The graphical representation on the card acts as
7 a guide for adjustment of the output intensity of the source in relationship to an accepted
8 standard, that is such as the "'Millennium" from Bausch and Lomb® . In this way the spectral and
9 power characteristics of the various elements involved in delivering light to the eye are integrated Ointo a single and easily manageable variable. This greatly reduces the complexity of judging the Ibest intensity to use in a given situation.2 The art of the present invention also comprises a ferrule or connector having an 3internal bore, preferably stepped, which is substantially parallel with the lengthwise axis4 of the ferrule body. The aforesaid bore allows for placement and bonding or potting of 5 an optical fiber within and through said ferrule body. Externally, said ferrule body is also βstepped in a unique form in order to optimally function as described herein.7 Where provided herein, dimensions, geometrical attributes, and thread sizes are8 for preferred embodiment informational and enablement purposes. Alternative 9embodiments may utilize a plurality of variations of the aforesaid without departing from Othe scope and spirit of the present invention. The art of the present invention may be Imanufactured from a plurality of materials, including but not limited to metals, plastics,2glass, ceramics, or composites.3 4 BRIEF DESCRIPTION OF THE DRAWINGS 5 Numerous other objects, features, and advantages of the invention should now become 6 apparent upon a reading of the following detailed description taken in conjunction with the 7 accompanying drawings, in which: 8 Fig. 1 is a top plan view of a preferred embodiment of the coaxial illuminated laser 9endoscopic probe and active numerical aperture control apparatus showing illumination and 0 laser light paths without the phototoxicity card, power meter, and ferrule connectors .
1 Fig. 2 is a perspective view of the arc lamp source and mount. Fig. 3 is an assembly view of the arc lamp source and mount.
3 Fig. 4 is a front side plan view of the first lens mount, shaft mounted cam, and shutter
4 with a closed position shutter shown in phantom.
5 Fig. 5 is a front side plan view of the steering mirror, post, bracket, ball slide, and
6 solenoid in a non-energized extended position.
7 Fig. 6 front side plan view of the first output for laser and illumination light and the
8 switch for sensing the recess in the alignment barrel.
9 Fig. 7 is a cross sectional view taken along line 7 - 7 of Fig. 6 without the switch body0 attached. 1 Fig. 8 is a side plan view of the ferrule connector without the recess for preferrably laser2 and illumination use.3 Fig. 9 is a cross sectional view taken along line 9 - 9 of Fig. 8.4 Fig. 10 is a side plan view of the ferrule connector with the recess for preferably 5illumination use. 6 Fig. 11 is a cross sectional view taken along line 11 - 11 of Fig. 10.7 Fig. 12 is a front side plan view of the front panel of the coaxial illuminated laser8 endoscopic probe and active numerical aperture control apparatus housing showing the first 9output, illumination level control knob, photoxicity risk card, and laser power meter display and 0 sensor.1 Fig. 13 is a right side plan view of the right panel of the coaxial illuminated laser 2 endoscopic probe and active numerical aperture control apparatus housing showing the second 3 output, illumination level control knob, laser connector, power and laser switches, and 4photoxicity risk card. Fig. 14 is an electronic schematic diagram of the laser power meter 5 circuitry. 6 Fig. 15 is an optical schematic diagram of the preferred embodiment of the coaxial 7 illuminated laser endoscopic probe and active numerical aperture control apparatus showing 8 laser and illumination rays, reflectors, mirrors, and lenses.9 Fig. 16 is an optical schematic diagram of an alternate embodiment of the coaxial Oilluminated laser endoscopic probe and active numerical aperture control apparatus showing llaser and illumination rays, reflectors, mirrors, and lenses.
Fig. 17 is an optical schematic diagram of a further alternate embodiment of the coaxial illuminated laser endoscopic probe and active numerical aperture control apparatus showing laser and illumination rays, reflectors, mirrors, and lenses. Fig. 18 is an optical schematic diagram of another alternate embodiment of the coaxial illuminated laser endoscopic probe and active numerical aperture control apparatus showing
6 laser and illumination rays, reflectors, mirrors, and lenses. Fig. 19 shows a left side plan view of the first lens mount. Fig. 20 shows a front side plan view of the first lens mount at a full intensity position Fig. 21 shows a front side plan view of the first lens mount at a dimmed intensity Oposition. 1 Fig. 22 shows a top plan view of an implementation of the alternate embodiments of the2coaxial illuminated laser endoscopic probe and active numerical aperture control apparatus as3 shown in the optical schematics of Figs. 16 & 17 showing illumination and laser light paths 4without the phototoxicity card, power meter, and ferrule connectors .5 Fig. 23 shows a side plan half cross sectional view of the preferred embodiment of the 6first and second lenses which correct for color, spherical aberration, and coma and have a back7focus 20mm from the apex of the last element and a numerical aperture of .5.8 Fig. 24 shows an optical schematic of the first lens set, collimated space, dichroic hot 9mirror filter, and second lens set with illumination light path rays shown. 0 Fig. 25 shows a detailed side plan half cross sectional view with dimensional attributes1of the preferred embodiment of element 1 of the lens shown in Fig. 23. 2 Fig. 26 shows a detailed side plan half cross sectional view with dimensional attributes3of the preferred embodiment of element 2 of the lens shown in Fig. 23. 4 Fig. 27 shows a detailed side plan half cross sectional view with dimensional attributes5of the preferred embodiment of element 3 of the lens shown in Fig. 23. 6 Fig. 28 shows a detailed side plan half cross sectional view with dimensional attributes 7 of the preferred embodiment of element 4 of the lens shown in Fig. 23. 8 Fig.29 shows an electrical schematic diagram of the coaxial illuminated laser endoscopic 9probe and active numerical aperture control apparatus. 0 Fig. 30 shows a top perspective view in black and white photographic form of a preferred1embodiment of the coaxial illuminated laser endoscopic probe and active numerical aperture
1 control apparatus showing illumination and laser light paths without the phototoxicity card, 2 power meter, and ferrule connectors . 3 4 DETAILED DESCRIPTION 5 Referring now to the drawings, there is shown in the Figures both preferred and alternate 6 embodiments of the coaxial illuminated laser endoscopic probe and active numerical aperture 7 control apparatus 10 also herein described as an illumination and laser source 10. There is 8 provided a device 10 for providing non-coherent illumination light 11, 62 and coherent laser 9 treatment light 14 through a single optical fiber 60 of the size typically used for laser treatment 10 only in a safe, effective, and user friendly manner. The apparatus is especially suited for use
1 lduring ophthalmic surgery.
12 The present art, in a preferred embodiment, utilizes a 75 watt xenon arc lamp 36 for its
13high luminance illumination (light density), greater than 6000 °K color temperature, and greater 14than 95 color rendering index. A unique and useful feature is the very high luminance and small 15 size plasma ball formed on the end of the lamp 36 cathode. If imaged correctly the plasma ball 16is bright enough to provide the required illumination input to a small fiber such as that used for 17laser treatment. The xenon arc lamp 36 further provides an extremely small point light source 18 which allows for a smaller output illumination beam 37 diameter. Unique to the present lamp 19source is a mount 38 which allows for replacement of the lamp 36 and yet retains the location
2 Oof the plasma ball of said source 36 precisely at a predetermined location within the optical center 2135 of the apparatus.
22 A classic spherical reflector 40 and two lens 42, 58 light collection layout is utilized
23rather than other lower part count layouts, such as using an elliptical reflector or a combination 24 of a parabolic reflector and lens. This teclinique allows maximum collection efficiency with a 25 minimum of geometric aberration. The lamp 36 is located at the geometrical center 35 of the 26reflector 40 and at the focus (focal point) of the first lens 42. Light that is incident on the 27reflector 40 is reflected back to the lamp 36. This forms an upside down or inverted image of the 28 source 36 coincidental to the source 36. The first lens 42 collimates light from the source 36 and
29the upside down or inverted image. The second lens 58 is located coaxial to the first lens 42 and
3 Ofocuses the light at its focal point. The output optical fiber 60 is located at the focal point of the 3 Isecond lens 58. The aforesaid reflectors 40 are preferably spherical rather than parabolic in order
lto reflect illumination light in the same form as sourced from the arc lamp 36. 2 Best form lenses 42, 58 (piano convex aspheric, facing each other) are used in the present 3 art. It was discovered that chromatic aberrations, caused by the lenses, gave the output of the 4 optical fiber 39, 60 either a yellow or blue cast. This is not a problem with other ophthalmic 5 sources because the source is many times larger than the output optical fiber. A color corrected 6"f l"or possibly .5 numerical aperture lens set 42, 58 consisting of four elements was designed 7 to be utilized for each lens. Each of the elements is coated with a MgF (magnesium fluoride) 8 anti-reflective coating to minimize light losses, with other anti-reflective coatings or layers also 9utilizable. Use of the achromatic lens sets allows a high fidelity image of the illumination source
1036 to be focused onto the end of the optical fiber 60, 64. That is, the multi-element lenses allow
1 lfor a minimum of cliromatic aberration. The aforesaid four element lens set is shown and 12 specifically described in the Figures.
13 An additional separate illumination path 62 is possible with the present art. A 0.5 system
14numerical aperture or "f 1" lens is the greatest practical because of limitations to the numerical 15aperture of available optical fibers. This equates to 60 degrees full angle. When the spherical 16reflector 40 is considered, an additional 60 degrees is provided from the total of 360 degrees
17 available. Consideration of the vertical rotation around the source 36 is impractical because of
18 shadows caused by the lamp 36 electrodes. A total of 240 degrees of horizontal rotation around 19the lamp 36 are left unaccounted for. Allowing for optics mounts 44 does account for some 20additional amount. However, at least half of the illumination output is available. This leaves
2 lroom for a second light path 62 located orthogonal to the first path 11 along with the second fiber 22output 64. No other conventional illumination light source incorporates multiple light paths from 23a single lamp, that is two independent collection systems for illumination light. The independent 24 nature of the two paths 11, 62 allow different filtering and intensity control settings to the two 25outputs 39, 41.
26 Output dimming of the present art illumination system is accomplished by steering the
27 first (collimating) or penultimate lens 42 in a fashion that does not change the lens 42 numerical 28 aperture or introduce shadow artifacts into the beam 37. The lens set mount 44 has two halves
2946 and a flat spring 52. The first part 48 is attached to the optics bench 12, the second part 50
3 Oholds the lens set 42, and the spring 52 connects the two 48, 50 together on one side. Pressure 3 Ion the lens mount second part 50 causes the spring 52 to deflect and the lens 42 to move in a
1 direction generally perpendicular to the optical axis. This results in motion or movement of the 2 image across the face of the optical fiber 60, 64 whereby the peak illumination of the beam 37 3 is not centered on the optical fiber 60, 64 face during dimming. Due to the aforesaid, the 4 reduction of the output light from the fiber 60, 64 without affecting the color (i.e. color 5 temperature) or aperture of the output is achieved. In a preferred embodiment a shaft mounted 6 cam 54 applies the pressure to the lens mount second part 50 and spring 52. A control knob 56 7 is attached to the other end of the shaft 53 and allows the user to select the desired illumination 8 level by rotating the knob 56. This method is capable of providing at least 95% reduction in 9 output illumination intensity. In a preferred embodiment, a shutter 57 is mounted upon the shaft 1053 and is rotated across the illumination beam 37 in order to fully attenuate the output 1 lillumination intensity upon full rotation of said knob 56. Alternative embodiments may utilize
12 other methods, including but not limited to electric or electronic drives, to rotate said shaft 53
13 instead of said knob 56.
14 A dichroic "hot" mirror filter 66 is placed in the collimated space 61 between the 15 illumination lenses 42, 58. This provides both UV and IR filtering of the light. Brackets are 1 βattached to the hot mirror 66 mount to provide a means for additional user selectable filters. 17Positioning of the filters is critical because this is the only area where the light 11 is generally
1 δnormal to the filter surface. Location of the filter 66 on the other sides of the lenses would cause 19the light to have many undesirable incidence angles (between 0 and 30 degrees). Variation in
2 Othe incidence angle causes dichroic reflectors or filters to have a shift in their affect. If 2 labsorption filters are used, placement outside the collimated space 61 will cause an increase in 22reflective losses and heating problems.
23 The output optical fiber connector 98 is uniquely configured to provide the precise
24positioning required while reducing cost. A precise connector or mating end 116 is combined 25 with an integral retention thread 130 to reduce parts cost and assembly time. An optional groove 26or recess 148 is placed on a second version of the connector to provide for sensing the difference 27between illumination only and laser compatible output fibers. Placement of a smooth diameter 28 connector 74 into the output activates a switch 72 which will allow the laser power to be mixed.
29Either the lack of a connector 98 or the groove or recess 148 under the switch 72 will cause the
30 switch 72 to not activate and the laser power will not be mixed in.
31 Regarding mixing of laser treatment energy or light 14, laser light 14 is delivered to the
1 system via a preferably 50 micron optical fiber 16 or equivalent. The connector 18 on the laser 2 end is configured to be compatible with the laser and to provide the necessary interface to signal 3 to the laser that a fiber is connected. The laser and light source 10 end preferably uses an SMA 4905 connector or equivalent to allow repeatable connections of the laser delivery fiber 16. Laser 5 light 14 exiting the delivery fiber is preferably collimated using a 16 mm focal length achromatic 6 lens or equivalent 20, i.e. laser collimating lens, which can also be utilized to focus the 7 collimated laser beam 22. The position of the fiber 16 is adjusted to be at the focal point of the 8 lens 20. The input laser connector 18 and collimating lens 20 are located so that the collimated 9 beam 22 is orthogonal to and intersects the center of the illumination axis 11 between the 1 Oillumination lens sets 42, 58 (the collimated area for illumination light). If all safety
1 lrequirements are met (i.e. laser output compatible fiber inserted and selection switch for laser 12 output activated) a steering mirror 24 reflects the collimated laser light 22 into the center of the 13 illumination axis 11. The steering mirror 24 is a first surface piano that is positioned at 45 14 degrees to the laser light 14 and is located in the center of the illumination axis 11 (when laser 15mode is active). A unique aspect of the present invention is that the thickness of the mirror 24 16is shaped to appear as a circle when viewed along the illumination axis. Due to the 45 degree 17 surface orientation, the shaping causes the mirror 24 surface to appear elliptical when viewed Iδfrom a normal angle. The size of the mirror 24 is chosen to be minimally larger that the 19 collimated laser beam 22. Placement of the steering mirror 24 in the center of the illumination
2 Oaxis 11 causes the light rays that would normally be there to be blocked and a shadow to appear 2 lin the center of the output light cone. The second illumination lens 58 focuses the laser light 14 22reflected by the steering mirror 24 onto the end of the output fiber 60, 64. Because the length of 23the output optical fiber strand is relatively short, the incidence angle of light entering the input 24 end is very nearly the same angle on the output end. This results in the output of the fiber strand 25having a cone of white light with a shadow in the center nearly filled with the laser aiming beam 26(treatment beam during treatment). That is, the laser provides an aiming beam, typically red, 27 when not fully activated for treatment and a treatment beam, typically green, when fully 28 activated. Without the shadow caused by the steering mirror 24 the aiming beam would be
29entirely washed out or imperceptible except at very low illumination levels.
30 Alternate embodiments may utilize more than one steering mirror 24 or place the steering 3 lmirror 24 outside of the illumination axis or illumination light path 11 and direct the laser light
114 through an aperture 158 in said spherical reflector 40 and thereafter through the arc lamp 36 2 plasma ball or through a dichroic reflector 160 or a reflector having an aperture 162. All of the 3 aforesaid alternate embodiments place the laser light 14 within the collimated space 61 and 4 utilize the second lens 58 for focus upon the output optical fiber 60. Moreover, all of the 5 aforesaid alternate embodiments provide for a second light path 62 output as seen in the Figures. 6 7 The laser steering mirror 24 is mechanically mounted on a thin post 28 that holds it in 8 place while minimizing the loss of illumination light 11. The post 28 is mechanically connected 9 to a bracket 30 which is connected to a solenoid 32. The solenoid 32 causes the bracket 30 and lOalso the steering mirror 24 to move into one of two positions. Position one is outside the
1 lcollimated illumination and laser light. This position is used for no laser delivery and allows the 12 illumination path to operate unaffected. Position two is with the steering mirror 24 located to 13reflect the laser light into the illumination path 11. Motion of the solenoid 32 and bracket 30 are 14controlled by a precision ball slide 34. Use of the slide 34 insures repeatable positioning of the 15mirror 24.
16 As described, unique to the present art is a coaxial laser and illumination path apparatus
1710 which heretofore has not be available or utilized. Also unique to the present art is a highly 18 efficient illumination system which utilizes spherical reflectors 40 and associated lenses 42, 58 19to capture a maximum light output and also provide a twin path illumination light output from
20a single lamp source in order to feed fibers of diameter less than 500 microns. Further unique 2 Ito the present art is a laser or steering mirror 24 having a solenoid 32 selectability which provides 22an aiming hole within the illumination path 11 for laser placement. Still further unique to the 23present art is an illumination arc lamp 36 system having an extremely small point light source 2436 which allows for an extremely small illumination focus size or numerical aperture output. 25 Also unique to the present art is an arc lamp 36 mount 38 which precisely and interchangeably 26places the plasma ball of the arc lamp 36 at the focus or optical center 35 of the optics system. 27 Also unique to the present art is a unique dimming mechanism which moves the focal point of 28 an output dimming or first lens 42 in order to provide dimming without introducing artifacts,
29chromatic aberrations, or change of color temperature. Also unique to the present art is a
30 capability of connection with existing conventional laser light sources whereby laser treatment 3 land illumination are both provided at an output of the present art apparatus 10. The optical
1 system of the present apparatus 10 is uniquely capable of accepting the input cone angles of the 2 illumination 33 and laser light 15 placed at the output optical fiber 60 and substantially 3 reproducing said cone angles at the output of the optical fiber, typically where the endoscopic 4 probe is located, with any aberrations caused by the optical fiber itself. 5 Further alternate embodiments of the present art apparatus 10 may utilize parabolic 6 reflectors instead of spherical reflectors in order to collimate the illumination source 36. This 7 technique would eliminate the need for the first collimating lens 42 and allow transmission of 8 the laser beam 22 through an aperture within the parabolic reflector or via a steering mirror 24 9 within the collimated space 61. Still further alternate embodiments may utilize an elliptical 1 Oreflector having two focal points whereby the illumination source 36 is placed at the first focal 1 lpoint and the output fiber 60 is placed at the second focal point with the laser beam 22 introduced 12through an aperture within the elliptical reflector or via a steering mirror 24 between the 13 illumination source 36 and the output fiber 60. This latter alternate embodiment requires 14 focusing the laser beam 22 onto the output fiber 60 via a lens placed within the laser beam path 1522 prior to the output fiber 60 yet allows elimination of both the first collimating lens 42 and the
1 δsecond focusing lens 58.
17 Some of the variables which determine the phototoxicity risk level during vitreoretinal
18 surgery include the spectral and power characteristics of the light source used, the type and size 19of the endoilluminator probe, the length or duration of the surgical procedure, and the area (size)
2 Oof the illuminated tissues. In each case the surgeon must make a risk-benefit judgement about 21the intensity of light to be used. Use of insufficient intensity may result in inadequate 22visualization and adverse effects more serious than a retinal photic injury. Currently, the 23calculation of the exposure time required to reach a point of injury is a tedious chore involving 24 the numerical integration of the spectral power density function of the light source 36 with a 25hazard function (see ISO 15752), and specific knowledge of the surgical illumination area and 2 βendoilluminator characteristics.
27 The present art invention further represents a novel apparatus and method for providing
28the ophthalmic surgeon with graphical photoxicity risk information in a clear and easy to
29understand manner. In a preferred embodiment, an inexpensive photoxicity risk card 76 is 30removably attached to the control panel of the surgical illumination and laser light source 10.
3 lPreferably, the present art card 76 is attached in close proximity to the light intensity control knob
156 in order to show the relationship between the output intensity of the light source and the
2 likelihood of photic injury. The card 76 is preferably included with each endoilluminator
3 instrument, i.e. optical fiber, that is calibrated to represent the phototoxic performance of that
4 instrument type when used with a particular type of light source. The graphical representation
578 on the card 76 acts as a guide for adjustment of the output intensity of the source 10 in
6 relationship to an accepted standard, that is such as the "Millennium" from Bausch and Lomb®.
7 In this way the spectral and power characteristics of the various elements involved in delivering
8 light to the eye are integrated into a single and easily manageable variable. This greatly reduces
9 the complexity of judging the best intensity to use in a given situation. Alternative embodiment0 graphical representations 78 could present other information regarding the light output such as 1 lumen output (a unit that is weighted by the photopic response of the eye). Other representations2 could present threshold information when used with special dyes or colored light filters.3 A preferred embodiment of the invention comprises a card 76 that is die-cut from white 4chipboard stock that is approximately the weight of a business card. The shape of the card 76 is δgenerally square with a slot 90 removed from one side to enable the card 76 to be placed behind 6the intensity control knob 56 of the illumination and laser source 10 while providing clearance7 for the control shaft 53 which is turned by said knob 56. In a preferred embodiment, four δlocation pins 92 are attached to the front panel of the illumination and laser source 10 enclosure. 9The pins 92 provide boundaries for card 76 location and tend to inhibit rotation of the card 76 Owith the control knob.1 In a preferred embodiment, onto the face of the card is printed a circular shaped scale 84 2that has different color bands 86 representing the phototoxicity risk at a given intensity level, for 3 example green, yellow, and red. The control knob 56 has an indication line that points to the 4 current output intensity level and concurrent phototoxicity risk associated with the probe being 5used. Unique to the present art is the ability of the card 76 to indicate output intensity at the βoptical fiber output. The card 76 is meant to be disposed of after a single use and replaced with7a new one provided with each optical fiber instrument. In this manner the output of the light δ source 10 is recalibrated each time it is used. The calibrated unit type may vary with different 9instrument styles to provide the surgeon with the most pertinent information possible.0 As aforesaid the card 76 provides a known point of reference relative to the prior art lillumination devices. For example, if the surgeon maintains the knob 56 indicator line within
Ithe green color band, he or she will understand that the light intensity output is within the safe
2 intensity of the prior art illuminators such as the "Millennium" from Bausch and Lomb®. This
3 control phenomena is especially useful when utilizing more powerful illumination sources 10
4 such as described herein. That is, the surgeon must have a prior art point of reference when
5 utilizing more powerful and modern illumination systems such as the present art. The art of the
6 present invention may further provide several bands which do not provide a reference to the prior
7 art but instead indicate phototoxicity levels or light intensity levels directly to the surgeon. δ Unique to the present art is the ability of the manufacturer of the optical fiber to provide
9 a phototoxicity risk card 76 which accounts for attenuation and spectral absorption within the 0 optical fiber provided with said card 76. Thus for example, if an optical fiber is highly1 attenuating, the card may indicate that the surgeon must turn the intensity control knob 56 to a2higher level in order to obtain an equivalency to one or more of the aforesaid prior art3 illuminators or to achieve a desired photo-illumination output.4 The art of the present invention also comprises a ferrule or connector 98 having5an internal bore 102, preferably stepped 104, which is substantially parallel with the 6lengthwise axis 100 of the ferrule body 98. The aforesaid bore 102 allows for placement7 and bonding or potting of an optical fiber within and through said ferrule body 98. 8 Externally, said ferrule body 98 is also stepped 112, 148 in a unique form in order to 9optimally function as described herein.0 In a preferred embodiment, the ferrule body 98 has an external end 114 and a1mating end 116 and externally comprises a substantially cylindrical head 118 of a first2diameter 120 having a first end 122 and a second end 123, said first end 122 co-located3with said external end 114. Said ferrule body 98 further externally comprises a lip 124 4of greater diameter than said head 118 and having a first side 126 and a second side 128 5with said first side 126 mounted with said second end 123 of said head 118. A threaded 6portion 130 of preferably smaller diameter than said head 118 is attached with and 7 extends from said lip 124 second side 128. In a preferred embodiment, said threaded 8portion 130 first comprises an 8-32 UNC thread with a first end 132 and second end 134, 9said first end 132 connected with said second side 128 of said lip 124. Also in a preferred0embodiment, said threaded portion 130 has a groove 136 of approximately .030 inch at
1 said first end 132 with approximately .090 inch of said thread 130 thereafter following 2 and another approximately .030 inch groove 136 following said thread 130 at said second 3 end 134. Externally the ferrule body 98 also has an alignment barrel 138 having a first 4140 and second 142 end following said threaded portion 130, said first end 140 attached 5 with said threaded portion 130. The second end 142 of said alignment barrel 138 is co- 6 located with said mating end 116 of said ferrule body 98. Also, said second end 142 of 7 said alignment barrel 138 contains an orifice 144 of substantially equivalent or slightly δ greater diameter as the optical fiber mounted within said stepped bore 102. Said orifice 9144 is interconnected with said internal stepped bore 102. In an embodiment of the lOpresent art, said orifice is approximately .011 inch in diameter and .025 inch in length. llAlso in a preferred embodiment, said alignment barrel 138 has a chamfer 146 at the 12 circumference of said second end 142. Preferably said chamfer 146 is of approximately 1345 degree angle and .015 inch in length. Alternative embodiments may utilize chamfers
14 of different angles or shapes or forego use of a chamfer altogether.
15 The alignment barrel 138 of the present art is uniquely shaped within the
1 βembodiments to indicate whether laser light or illumination light should be applied to the 17 optical fiber. In a preferred embodiment of the laser ferrule, the alignment barrel is of Iδuniform diameter, approximately .118 diameter, which indicates to the source 36 that 19laser light or energy is desired. In a first alternative embodiment or illumination ferrule,
2 Othe alignment barrel contains a recess 148 located approximately .075 inch from said 21barrel 138 second end 142 and extending approximately .268 inch from said second end 22142. When utilized, the illumination and laser source 10 detects this recess and 23determines that illumination light and not laser light is desired. Further alternative 24 embodiments may utilize the aforesaid recess 148 embodiment for laser light and the 25uniform barrel diameter for illumination light.
26 Internally said stepped bore 102 first comprises a first larger bore substantially
27 within said head portion which is of approximately .098 inch diameter and extends 26 substantially the length of said head. A second intermediate bore of approximately .063 29inch diameter extends from said first larger bore to said orifice 144 within said threaded
1 portion 130 and said alignment barrel 138. Also in a preferred embodiment, the orifice 2144 length is approximately .025 inch. Alternative embodiments may utilize first and 3 second bores and orifices having a plurality of diameter and length sizes provided that the 4 diameter portions are smaller than the ferrule external portions within which each is 5 located. 6 When assembled with an optical fiber, the optical fiber extends through said bore 7102 and orifice 144 and terminates substantially flush with said ferrule body 98 mating δ end 116 or second end 142 of said alignment barrel 138. Preferably said optical fiber is 9 held within said bore 102 via potting or adhesive compounds surrounding said fiber and
10 attaching with said bore 102 of the ferrule 98.
11 In a preferred embodiment, the external head 118 diameter is approximately.234 12inch with a length of approximately .375 inch. The lip 124 external diameter is 13 approximately .312 inch with a thickness of approximately .025 inch. Also, said 14 alignment barrel 138 is approximately .118 inch in diameter and .380 inch in length. 15 Where provided, dimensions, geometrical attributes, and thread sizes ate for 16preferred embodiment informational and enablement purposes. Alternative embodiments 17 may utilize a plurality of variations of the aforesaid without departing from the scope and
1 δspirit of the present invention. This is especially true as relating to said head 118, lip 124, 19and threaded portion 130. Said lip 124 may be integrated as part of the head 118 or
2 Oremoved completely. Also, the position, location, and type of threaded portion 130 may 2 lvary. Said threaded portion 130 may not utilize said grooves 136, utilize grooves of a 22 shorter or longer length, or have said head 118 and lip 124 diameters sized substantially 23the same as or smaller than the outside diameter of said threads 130. The art of the 24present invention may be manufactured from a plurality of materials, including but not 25limited to metals, plastics, ceramics, or composites.
26 Unique to the present invention is the integral inclusion of a laser power meter 150
27having a sensor 152, a power display 154, and associated control circuitry 156. The power meter 28150 allows a surgeon to place the endoscopic fiber optic probe onto said sensor 152, energize the 29laser through the illumination and laser source 10 and measure the laser power output as seen on
said display 154. Inclusion of the aforesaid is especially useful due to variations in optical fibers or to account for attenuation through the illumination and laser source 10. By utilizing the power meter 150, the surgeon has complete knowledge of the laser power transmitted to the surgical site. Alternative embodiments may utilize said power meter 150 for measurement of the output illumination 37 intensity as well as the laser light 14 power. In operation, the surgeon connects a laser light source via optical fiber to the input laser connector 18 on the apparatus 10. The surgeon thereafter connects a ferrule connector 98 with an integral optical fiber connected with an endoscopic probe at the first output 39 or for
9 illumination only at said second output 64. If said ferrule connector 98 at said first output 39 Odoes not have the aforedescribed recess 148, the apparatus 10 will allow the steering mirror 24 Ito position within the illumination light path 11 and further allow transmission of laser light. If2the surgeon desires to measure laser power output, he or she places the output end of the3endoscopic probe onto said sensor 152 and upon full laser activation, reads the laser power 4 output on the display 154. If the apparatus 10 is powered, the surgeon proceeds to illuminate the 5 tissues of concern with a cone of white illumination light having a shadow where the laser beam 6will be placed and a typically red laser aiming beam within said shadow. Upon full activation 7 of laser power, a typically green treatment laser beam replaces said typically red aiming beam to δtreat the tissues of concern. All of the aforesaid illumination and treatment may be achieved with9a single incision and through a single optical fiber of smaller diameter than prior art sources. 0 Those skilled in the art will appreciate that a coaxial illuminated laser endoscopic probe land active numerical aperture control apparatus 10 (illumination and laser source) and method 2 of use such has been shown and described. The apparatus and method of use allows for 3 simultaneous transmission of illumination and laser treatment light through a single optical fiber 4 of a size which is typically utilized for laser treatment light only. The apparatus and method 5 further provides control of the angular light output from the endoscopic probe attached with said 6optical fiber. The apparatus also provides for distinct and separate illumination without 7utilization of the treatment laser while providing complete intensity control of said illumination. 8 Those skilled in the art will appreciate that a medical light intensity phototoxicity control or risk 9card 76 has also been shown and described for use with the present art. Said phototoxicity risk 0 card 76 is especially useful for quick and easy determination of illumination intensity output from la specific type of optical fiber or higher power source such as the present art. Those skilled in
lthe art will appreciate that a photon illumination and laser ferrule connector 98 has also
2 been shown and described. Said ferrule 98 is especially useful for quick and positive
3 connection of an optical fiber to a laser or illumination source 10 as herein described and
4 further allows said source 10 to distinguish the optical fiber type or use, that is for
5 illumination or medical laser application. The present art device is useful during surgery
6 and especially ophthalmic surgery. Also, those skilled in the art will appreciate the
7 integral inclusion of a laser optical fiber output power meter.
8 Having described the invention in detail, those skilled in the art will appreciate that
9 modifications may be made of the invention without departing from its spirit. Therefore, it is not0 intended that the scope of the invention be limited to the specific embodiments illustrated and 1 described. Rather it is intended that the scope of this invention be determined by the appended2 claims and their equivalents.3