CA2115770C - Laterally reflecting tip for laser transmitting fiber - Google Patents
Laterally reflecting tip for laser transmitting fiberInfo
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- CA2115770C CA2115770C CA 2115770 CA2115770A CA2115770C CA 2115770 C CA2115770 C CA 2115770C CA 2115770 CA2115770 CA 2115770 CA 2115770 A CA2115770 A CA 2115770A CA 2115770 C CA2115770 C CA 2115770C
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- tip
- fiber
- mirror surface
- reflecting mirror
- distal
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Abstract
A tip for mounting upon a distal end portion (14) of a flexible elongated light transmitting fiber (16) is provided. An elon-gated body has a distal head portion (24) and has a plurality of flexible legs (26, 28) extending proximally from the head portion.
A clamping arrangement (20) is operably associated with the body for urging the legs radially inward to clamp the distal end por-tion (14) of the fiber therebetween. The mounting arrangement is particularly suited for use with laterally reflecting tips, and such a tip has a lateral passageway (88) providing the ability to flush fluid across the reflecting surface (38) of the tip in order to keep the same clean. Improved reflecting surfaces are also disclosed.
A clamping arrangement (20) is operably associated with the body for urging the legs radially inward to clamp the distal end por-tion (14) of the fiber therebetween. The mounting arrangement is particularly suited for use with laterally reflecting tips, and such a tip has a lateral passageway (88) providing the ability to flush fluid across the reflecting surface (38) of the tip in order to keep the same clean. Improved reflecting surfaces are also disclosed.
Description
~ WO 93/03678 2 1 ~ ~ 7 7 ~PCr/US9~/06693 TlATERAT~r~y REFr T~rTJN~ TTP FOR T.A.CT`R TRAN ~ I NG FTRT R
~3ackqro~n~1 of The Invention 1. Field Of The Invent i on The present invention relates generally to devices for use in laterally reflecting light energy from a f lexible elongated light transmitting f iber, and more particularly, but not by way of limitation, to such devices designed for use with laser light transmitting f ibers .
~3ackqro~n~1 of The Invention 1. Field Of The Invent i on The present invention relates generally to devices for use in laterally reflecting light energy from a f lexible elongated light transmitting f iber, and more particularly, but not by way of limitation, to such devices designed for use with laser light transmitting f ibers .
2. I~escrimtion Of The Prior Art = -One developing area of medical technology involves the application of light energy, typically laser light energy, to a site in the patient's body to alter, remove or destroy tissue in the patient's body. This may be done with bare fibers or with fibers having a metal tip on the distal end. Such tips typically absorb all or part of the laser energy 50 that the tip itself is heated to a cl ini~-Al ly significant extent whereby the tissue is at least partially treated by heat cnn~ rti~ln from the heated 2 o tip which is placed in contact with the tissue . - The tips also may have ~ L 8ULaS for directing a portion of the laser light either directly or by ref lection upon the tissue to be treated.
Many medical procedures ut;li~;n~ such tips are more easily accomplished if the laser energy is reflected laterally from the longitudinal axis of the fiber 60 that it can be directed upon tissue which would be difficult to treat with light emitted axially from the fiber.
rv Of The Tnvention ~-3 o The present invention provides a number of improvements in the construction of tips of the type generally described.
First, an; ~vt:d mounting construction ~5 provided WO 93/03678 - ' PCr/US9Z/06 2~1~770 -2- 69~
whereby the tip i8 easily and securely attached to the flexible elongated light transmitting fiber. In thi6 c~mh~ the invention provides an elongated body having a distal head portion and having a plurality of f lexible legs extending proximally from the head portion. A
clamping means is operably associated with the body for urging the legs radially inward to clamp the distal end portion o~ the fiber between the legs. This is preferably provided by a two-piece tip wherein the f irst piece includes the f lexible legs which have outer surfaces thereon which define a conically tapered outer suriace of the ~irst piece. The second piece includes a sleeve slidably received about the legs. The sleeve includes a conically tapered inner surface complementary to the conically tapered outer surface so that when the sleeve slides over the legs ~ngA, ort o~ the conically tapered inner surface of the sleeve with the c~nioAl ly tapered outer surface of the legs causes the legs to be biased radially inward to clamp the distal end portion of the 2 0 f iber therebetween . This mounting arrangement is use~ul on a variety of tip de6igns and is not limited to laterally transmitting tips.
In another aspect of the invention a laterally ref lecting tip is provided which ref lects 6ubstantially all incident laser light energy laterally outward through an aperture so that there is no cl;n;cAlly significant heating of the tip. The tip includes an elongated thin cylindrical body having a fiber receiving longitudinal opening therein for receiving the distal end portion of the fiber. The body has a lateral passAgeway defined diametrically therethrough and intersecting the longitudinal opening. A reflecting mirror surface means is defined on the body for reflecting light from the fiber laterally outward through the lateral passageway. The lateral passageway being cl; F~pO5~ diametrically through the body provides a f lushing means f or permitting surrounding fluid to flow through the lateral pA~a~eway across the reflecting mirror surface to reduce collection WO 93/03678 2 ~ 1 5 7 7 ~ Pcr/us92/o669~
Or contaminants on the reflecting mirror surface.
In another aspect of the invention an;, ~uv~d method i6 provided for forming a light reflecting mirror surface on a laterally reflecting tip. This is accomplished by providing a gold reflecting surface on the tip, and coining the gold reflecting surface to provide a superior ref lecting surf ace .
In yet another aspect of the invention a method is provided for forming a light reflecting mirror surface on lo a laterally reflecting tip. First a tip body is formed from a first metal other than gold. An underlying gold layer is then sputter deposited on the body. Finally an outer gold sheet is diffusion bonded under external pressure at elevated temperature to the underlying gold layer, with the outer surface of the outer gold sheet defining the light reflecting mirror surface. Preferably this light reflecting mirror surface is then coined to provide a superior reflecting surface.
Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the ~: , ~nying drawings .
Brief lm~ ri~tion Of The Drawinrlc FIG. 1 is a plan view of the light reflecting tip assembled with a f lexible elongated light transmitting f iber .
FIG. 2 i6 an elevation 6ectioned view taken along line 2-2 of FIG. 1.
FIG. 3 is a plan view similar to FIG. 1 of the elongated body of the two-piece tip assembly of FIGS. 1 and 2.
FIG. 4 is an elevation sectioned view of the body of FIG. 3 taken along line 4-4.
FIG. 5 is a right end view of the body of FIG. 4.
FIG. 6 is an elevation sectioned view of the sleeve piece of the two-piece tip assembly of FIGS. 1 and 2.
WO 93/03678 PCT/US92/0669,~
7 0 _4_ FIG. 7 is a schematic illustration similar to FIG. 2 showing the beam spread of a beam ref lected from a f lat mirror .
FIG. 8 i5 a view similar to FIG. 7 showing the beam spread of a beam ref lected f rom a concave mirror .
FIG. g is a view similar to FIG. 7 showing the beam spread of a beam ref lected f rom a convex mirror .
FIG. lo is ~ schematic illustration of the laser and ~ul~score with which the f iber and tip are u3ed .
FIG. 11 is an enlarged sectioned view of a portion of the ~ndc:,scu~ic tube of FIG. lO, illustrating the passage of the f iber and tip through a curved ~n~ scopic tube.
FIGS. 12A and ~3 and 13A and B schematically represent certain tests which were run to ~lPt~m;n~ reflective ef f iciency of the tips .
FIGS. 14 and 15 are graphic representations of the spreading of the light beam energy by a f lat ref lective mirror surf ace .
FIGS. 16 and 17 schematically illustrate the methodology of an example test which shows that there is no clinically signif icant heating of the tip .
Det~ 3escri~tion Of The Preferred F~hodiments Ref erring now to the drawings, and particularly to FIGS . 1 and Z, a tip and f iber assembly is thereshown and generally designated by the numeral 10. The assembly 10 includes a two-piece light reflecting tip 12 mounted upon a distal end portion 14 of a f lexible elongated light transmitting f iber 16 .
The two-piece tip 12 includes an elongated body 18 3 o which is best shown in isolation in FIGS . 3 -5 and a clamping sleeve 20 which is illustrated in isolation in FIG. 6.
The f iber 16 is a commercially available laser light transmitting f iber . Such f ibers include a f lexible elongated cylindrical core 22 which is ~uL~uullded by a rl;~tlr~;n~ of lower optical refractive index material which is overlain with an outer protective jacket. As seen in ~ W093/03678 2I1~770 PCr/[JS92/06693 FIG. 2, when assembled with the tip of the present invention, the outer rlA~ in~ and ~acket of the fiber 16 are preferably trimmed back to end at 23 with the fiber core 22 extending distally beyond the end 23 of the outer protective layers. Thi6 m;nirni zo- the pos6ibility of burning of the outer protective layers due to laser energy ref lected back f rom the mirror surf ace .
The elongated body 18 ha6 a distal head portion 24 and has first and second flexible legs 26 and 28 extending proximally from the head portion 24. Although there is no critical line of distinction between the head portion 24 and the legs 26 and 28, the head portion 24 can generally be described as having a lcngth 25 as seen in FIG. 3, and the legs 26 and 28 can generally be described as having a length 27. Head portion 24 has a squared-off flat end 21.
As used herein the terms distal and proximal are used in relation to the terminology generally used for the fiber 16 with the distal end of fiber 16 being indicated at 31 in FIG. 2, and with the proximal end of the fiber 16 being the other end which typically would be attached to the laser light source 108 (6ee FIG. 10). Thus the distal and proximal directions or relative orientations are provided for the tip 12 used in association with the fiber 16 .
The clamping sleeve 20 can be more generally described as a clamping means 20 operably associated with the body 18 for urging the legs 26 and 28 radially inward to clamp the distal end portion 14 of fiber 16 therebetween in a manner further described below.
As best seen in FIG. 4, a blind bore 30 is drilled into the proximal end 32 of body 18 thus defining partially cylindrical inner surfaces 34 and 36 on legs 26 and 28, respectively, which surfaces 34 and 36 define a body bore means 30 for closely receiving and clamping the distal end portion 14 of the fiber 16 therebetween.
The body 18 can be described as having a plurality of legs, which in the preferred ~-';r- t are two and only two legs 26 and 28. The head portion 24 has 2 reflecting WO 93/03678 PCr/US92/0669jl~
2115~70 -6-mirror surface means 38 defined thereon for reflecting light emitted from the di6tal end 31 o~ fiher 16 laterally outward. The body bore means 30 terminates short of the ref lecting mirror surf ace 3 8 .
S The legs 26 and 28 have proximal cr~n;cAlly tapered outer 6urface portions 40 and 42, respectively, which collectively define a conically tapered outer body 6urface 44 extending over a length 46.
A di6tal portion 48 of legs 26 and 28 defines a generally cylindrical outer surface 50 having f irst and second annular radially outward extending flanges 52 and 54 each of which has a distally facing shoulder 56 and 58, respectively, defined thereon.
The body 18 is preferably formed from a cylindrical stainless steel blanlc which is machined to have the appearance shown in FIGS. 3 and 4. The lateral pACc~geway 88 and legs 26 and 28 are partially formed by milling a slot having the width 39 as seen in FIG. 3 into the cylindrical blank. As further described below, the body 18 may also be formed of solid gold in which case it will be cast in the shape shown in FIGS. 3 and 4.
The clamping sleeve 20 which is shown in its ~nAcc~l-hled state in FIG. 6, is designed to be slidably received about the legs 26 and 28. Clamping sleeve 20 has an axial sleeve bore 60 defined through its proximal end 62 for closely receiving the fiber 16. Clamping sleeve 20 further includes a tapered conical sleeve counterbore 64 complementary to the conically tapered outer body surface 44 so that when the clamping sleeve 20 slides in a distal direction over the legs 26 and 28, engagement of the tapered conical sleeve counterbore 64 with the C~ i CA l l y tapered outer body surface 44, causes the legs 26 and 28 to be biased radially inwardly.
The clamping sleeve 20 further includes a thin cylindrical distal portion 66 and a thin cylindrical proximal portion 68 which as further described below are used in securing the two-piece tip assembly together and onto the f iber 16 .
~ WO 93~03678 ~ i 7 7 0 PCr/US92/06693 _ 7 _ As best seen in FIG . 2, a body abutment surf ace 7 0, which is an annular shoulder, is defined on the head 24 of body 18. A 61eeve abutment surface 72, which is the distal end of sleeve 20, is defined on the clamping sleeve 20 and is arranged to abut the body abutment surface 70 to limit sliding motion of the clamping sleeve 20 over the legs 26 and 28.
The tapered conical sleeve counterbore 64 and the conically tapered outer body surface 44 have an interference fit prior to abutment of the sleeve abutment surface 72 with the body abutment surface 70. Thus, with the fiber 16 in place as shown in FIG. 2, a6 the clamping sleeve 20 slides distally over the legs 26 and 28, the 61iding interference fit between tapered surfaces 64 and 44 causes the legs 26 and 28 to be cammed radially inward thus clamping f iber 16 therebetween .
After the sleeve abutment surface 72 engages the body abutment surface 70, the clamping sleeve 20 is secured to the body 18 by forming first and second circumferentially rolled crimps 74 and 76 in the thin cylindrical distal portion 66 of clamping sleeve 20 so that the crimps 74 and 76 engage the annular shoulders 56 and 58 to prevent the clamping sleeve 20 from sliding backwards off the legs 26 and 28. Additionally, the thin cylindrical proximal portion 68 of clamping sleeve 20 is further secured to the fiber 16 by t9;; L~lcally opposed staking crimps 78 and 80 as seen in FIG. 1.
It will be appreciated that the construction of the legs and clamping sleeve could be reversed so that the sleeve protrudes from the body with the legs being formed on a separate piece which slides into engagement with the sleeve. More generally, the tip 12 can be described as a two-piece tip including a first piece having a plurality of longitll~ i n;~ 1 1 y extending legs and a second piece in~ 9;n~ a sleeve slidably received about the legs.
The abutment surfaces 70 and 72 can be more generally described as a limit means 70, 72 for limiting insertion of the legs 26 and 28 within the clamping 61eeve 20 and WO 93~03678 ~ PCr/US92/066 ~ 770 ~\
thereby limiting a clamping force applied to the fiber 16 by the legs 26 and 28.
It i8 noted that the body 18 shown in FIG . 4 dif f ers in one aspect from the body 18 illustrated in FIG. 2, namely in regard to the construction of the ref lecting mirror surf acQ means 3 8 .
The reflecting mirror surface means 38 is preferably made of bi o _ ~tible 99 . g+ percent gold. This can be accomplished in at least two ways. In FIG. 4, the entire body 18 is made from gold and thus all that need be done to compLete the reflecting mirror surface mean6 38 is to treat the sur~ace to make it as smooth and ref lective as possible .
FIG. 2, on the other hand, illustrates a construction wherein the major portion of the body 18 is made of a first metal other than gold, preferably 316 st~inless ~teel. An underlying mirror support surface 82 is defined on this f irst material . Then gold is laid over the underlying support surf ace in 6uch a way as to f orm the gold reflecting mirror surface means 38. One preferred manner of doing this is to sputter deposit an underlying gold layer 84 onto the underlying mirror support surface 82, and then to diffusion bond a gold sheet 86 to the underlying gold layer 84.
The diffusion bonded gold sheet 86 preferably is formed from rectangular gold wire having a thickness of at least 0 . 014 inches thus providing a gold layer thick enough to prevent the chemical action of the ~iurL~ullding saline medium from corroding completely through the gold layer during typical medical treatment procedures. The gold sheet has a width approximately equal to the width 39 of mirror 6urface 38.
Regardless of whether the solid gold body of FIG. 4 or the stainless steel body with overlying gold layers of FIG. 2 is used, the final treatment of the gold reflecting mirror surface means 38 is preferably formed by coining the surf ace . Coining is a mechanical process whereby a very hard, ~mooth member is pressed against the surface 38 _ ~ WO 93/03678 2 i 1 5 7 7 o Pcr/us92/o6693 g to stamp it or coin it so that it too carries a smooth highly reflective impression.
As is further described below, the smooth, coined, gold reflecting mirror surface means 38 provides a means for reflecting substantially all of the light energy incident thereon from the fiber 16.
Alternatively, the mirror surface 38 could be made smooth by electro or -~ ~nic~l polishing or by chemical etching .
In designing a tip for maximum reflection so that substantially all laser light energy incident upon the reflecting surface 38 is reflected, it is n-~r^~r~ry to choose the reflecting material ~er~n~nt upon the particular laser being utilized . Dif f erent ref lective materials have more efficient reflective characteristics for different wavelengths of laser light. For example, when utilizing an Nd:YAG laser having a characteristic wavelength of 1064 or 1318 nanometers, or when using a Ho:YAG laser having a characteristic wavelength of 2100 nanometers, the reflective surface 38 is preferably made of gold.
On the other hand, for a frequency doubled Nd:YAG
laser having characteristic wavelengths of 532 or 659 nanometers, a platinum surface 38 i5 preferred.
Similarly, the platinum surface is preferred for an Alexandrite laser having a 680-800 nanometer tuning range, a Sapphire laser having a 680-800 nanometer tuning range, an Argon Ion laser emitting radiation with wavelengths in the 428-528 nanometer range, and for a dye laser having a 400-800 nanometer tuning range.
Gold and platinum are chosen as preferred mirror surfaces on the basis of their high optical reflectivities and their relative stabilities in a warm aqueous saline solution environment.
As is best seen in FIG. 2, the body 18 has a lateral p~csz~eway 88 defined .1; L,ically therethrough which intersects the body bore means 30. The lateral passageway 88 has diametrically opposite first and second end WO 93/03678 PCr/US92/06693 2~770 - ~
openings 9o and 92, respectively. The lateral passageway 88 extends across and runs parallel to the ref lecting mirror surface means 38, and thus due to the slope of the re1ecting mirror surface means 38, the second end opening 92 is substanti~lly smaller than the first end opening 90 of lateral passageway 88. .
The reflecting mirror surface means 38 is set at an angle 94 to the longitudinal axis 96 of the f iber 16 and tip 12 . Thus light exiting the dist~ 1 end 31 of f iber lo core 22 falls axially (with a small divt:r ~ence) onto the reflecting mirror surface means 38 and then is reflected laterally out the larger first end opening 90 of lateral passageway 88.
There is some angular diffusion of the light which reflects from the reflecting mirror surface means 38 80 that it tends to difuse into a conical beam, and the body 38 has a conical cavity 98 superimposed upon the larger first end opening 90 of lateral pas6ageway 88 thus permitting the ref lected beam to pass laterally outward 2 0 without impinging upon any other portions of the tip 12 other than the reflecting mirror surface means 38.
The tip 12 is constructed for usage in any number of medical ~Lu~eduLes wherein the tip is used to direct laser light onto human tissue to treat the same. The tip 12 is typically immersed in an aqueous saline solution dLuring operat$on, but it will be appreciated that often the solution is contaminated with proteins from the surrounding body tissue. If these proteins are allowed to build up on the reflecting mirror surface means 38, it of course will significantly degrade the operation of the tip 12. The lateral passageway 88 extending completely laterally through the body 18 over the ref lecting mirror surface means 38 provides a flushing means 88 for permitting ~uLLuu,ding fluid, typically saline solution, to flow in one of the first and second end op~nin~c 90 and 92, then across the reflecting mirror surface means 38, then out the other of the f irst and second end openings, thus tending to cleanse the ref lecting mirror surf ace WO 93/03678 2 1 1 ~ 7 7 0 means 38 and to reduce collection of contaminants on the ref lecting mirror surf ace means 3 8 .
The flushing of saline solution through the lateral p;-CCa~Pway 88 also aids in carrying away saline solution heated by laser light passing therethrough to prevent any . significant heat buildup adjacent the tip 12. As further shown below, the tip 12 is designed for substantially complete reflection of the laser light energy incident upon mirror 38. There is no clinically significant heating of tip 12.
FIGS. 7-9 are somewhat simplified versions of FIG. 2 and they illustrate various modifications that can be made to the reflecting mirror surface means 38.
FIG. 7 Lllustrates the flat planar reflecting mirror surface means 38 previously described with regard to FIGS.
2 and 4. In a preferred ~ the angle 94 of surface 38 is 373~, and the distal end 31 of fiber core 22 is cut square, i.e., it defines a plane normal to the axis 9 6 of the f iber . With such an arrangement, and with a highly reflective coined gold reflecting mirror surface means 38, the reflected beam 100, the outer extremities of which are shown in phantom lines will diverge slightly from a cylindrical beam due to divergence upon exiting fiber core 22 and due to imperfect reflection of the mirrored surface 38 so as to form a reflected light spot 102. In a preferred ~ nt the flat coined gold reflecting mirror surface means 38 of FIG. 7 is a means for providing a generally circular reflected light spot size 102 no greater than 3 mm diameter at a distance of 1. 05 cm along the central ray of the deflected beam from the central axis 96 of the fiber 16.
It is noted that with the specified angle 94, the reflected beam will reflect somewhat in a proximal direction. This back reflection is a significant aid in directing the reflected beam to hard-to-reach portions of cavities within the human body. The angle of reflection of the beam can of course be modified as desired by modifying the angle 94 and the conf iquration of the WO 93/03678 ~ PCr/US92/0669~
211~770 reflecting surface 38. Also, the distal end 31 o~ the f iber core 22 can be cut at an angle which will also affect the dispersion and direction of the light beam emitted theref rom .
A6 best seen in FIG. 2, there i5 an axial clearance between the distal end 31 of fiber core 32 and the reîlecting mirror surf~ce means 38. This permits the lo .. . - ~ ref lected beam to exit through the lateral p~C6~qP~ay 88 without impinging upon the fiber end 31 or any portion of the tip 12 other than the mirror 38.
DPrDn~l;n~ upon the type of treatment being conducted, it may be desirable for the reflected light spot 102 to be either more diffused or more cul.c~ L~lLed. This can be accomplished by modifying the reflecting mirror surface means 38 as shown in FIGS. 8 or 9 to U~ L~te or disperse the beam, respectively.
In FIG. 8, the reflecting mirror surface means 38 has a concave portion 104 which is impinged by the beam from fiber core 22 thus cullc~ Lc~ing the rPflertecl beam lOOA
to form a smaller reflected beam spot 102A as compared to FIG. 7.
In FIG. 9, the reflecting mirror surface means 38 includes a convex portion 106 which causes the reflected beam lOOB to be more dispersed and thus form a larger reflected beam spot 102B as compared to the apparatus of FIG . 7 .
Tt will be appreciated that FIGS. 7-9 are only schematically illustrated and are not nDcPcc~rily geometrically correct. The angles of the beams have been somewhat exaggerated to illustrate the difference between the various Dmhorl i ~5 .
FIG. 10 schematically illustrates the various apparatus with which the fiber 16 and tip 12 are typically used . The proximal end of the f iber 16 is connected to a laser 108 which produces the laser light which i5 trzmsmitted through the fiber 16 and then reflected by tip 12. In the pre5ent disclosure the word light is used in its broad sense, me~ning ele~ netic radiation which ~ WO 93/03678 2 1 1 ~ 7 7 0 PCr/US92/06693 propagates through space and include6 not only visible light, but also infrared, ultraviolet and microwave radiation. In the preferred ~ ';r~nt, the light transmitted by fiber 16 is laser light ~Loduc~d by the laser 108.
The fiber 16 is typically utilized with a conventional Pn~ scope 116, which may be rigid or flexible, and which carries the fiber 16 in a cylindrical passage 118 defined in an Pn~loficopic tube 120. The Pn~-6copic tube 120 may include a parallel optical viewing fiber (not shown) and parallel fluid flow conduits (not shown). Also, the cylindrical passage 118 may itself be utilized as a fluid flow passage to allow irrigating f luids to f low to the tip 12 .
It will be appreciated that tlprpn~l;n~ upon the medical procedure being performed, the endoscopic tube typically may need to pass through various curved cavities in the human body so as to reach the area to be treated.
In such case a flexible Pn~ ccope will be used.
The tip 12 and fiber 16 which are assembled according to the present invention pref erably are constructed so that they can pass through the cylindrical passage 118 of endoscopic tube 120 when the endoscopic tube 120 is contorted in the necessary fashion. Thus, the fiber 16 assembred with tip 12 must be capable of curving to pass through the curved cylindrical passage 118. Also, the fiber 16 and tip 12 must pass through the ~ &r~e 116 itself. Typically the most severe ~,ULVC~I_ULt: through which the f iber 16 and tip 12 must pa2~;s is the bend at connection 117 where the ~iber 16 enters the Pn~ scope 116 from a laterally offset position and then must pass into the tube 120. The radius of ~:ULVe~LULe of this bend on existing Pn~lc scopP~ is approximately lo cm. This passage may have a diameter on existing Pn~scop~c as small as 2.5 mm.
FIG. 11 is a schematic, 5egmented, cross-section portion of the endoscopic tube 120 in the curved area designated in FIG. 10. The fiber 16 and tip 12 are shown WO 93/03678 PCr/US92/06693 211~77~ -14-in phantom lines in FIG. 11 as they would appear when the tip 12 and f iber 16 are being run in a distal direction through the pasGage 118 80 that they ultimately will extend from the distal end of endo6copic tube 120 as illustrated in FIG. 10.
A typical passage 118 of available ~n~- scopic tubes 120 has a diameter of no greater than 2 . 5 mm. The preferred optical fiber described below has a design minimum bending radius of 1 cm which can easily conform to passage 118 50 long as the tip 112 can f it through the curved passage. Since the most severe bend to be encountered is that at junction 117, the fiber 16 and tip 12 should be 50 constructed and dimensioned A5 to provide an assembly capable of passing through a curved cylindrical passage having a diameter of 2 . 5 mm and a radius of ~uLv~Lu-e of 10 cm.
Prior art tip constructions for laterally reflecting tips have been relatively bulky and have been incapable of passing through such a narrow curved passage. The present invention has solved this problem. In a preferred ~mho~l;r L this is accomplished by ~ullaLLu~;Ling the tip 12 to have a length 122 (see FIG. 1) of 0 . 3543 inches (9 . 000 mm) and an outside diameter 124 of 0 . 0866 inches (2 . 200 mm). This tip is generally cylindrical in shape and is concentrically mounted upon the distal end portion 14 of fiber 16. Prcferably the tip 12 has a maximum diameter 124 of no greater than 2 . 2 mm, and a length no greater than 1 cm.
The preferred light transmitting fiber 16 for use with the tip 12 having the dimensions just described is a conventional fused silica fiber. This fiber has a minimum bending radius of 1 cm. The silica core has a diameter of 600 microns and the fiber with cladding has an outside diameter of 0.040 inch which is clamped within the bore 30 3 5 of tip 12 which has a bore diameter of 0 . 04 0 inches .
In this pref erred embodiment the tapered outer surface 44 and tapered inner counterbore 64 have an angle of taper such as indicated at 126 in FIG. 3 in the range ~ WO 93/03678 2 1 1 ~ 7 ~ ~ PCr/us92/o6693 of from 4.2 to 4.8O.
EfficiencY of Reflection Mea~u, ~ ~s of reflective optical power and intensity distribution over the ref lected beam were made on a group of nine f ibers having tips 12 with 99 . 9% gold reflective surface formed as dcscribed above with regard to FIG. 2. Similar measurements were also made on a COr r ~ v~ n~ group of bare fibers of identical manuf acture .
Specifically, measurements were made to assess and compare the ~é~ /ducibility of values of reflected and emitted power and radiated intensity di6tribution within each group of optical fibers and to compare the efficiency of the reflection by the actual gold surface relative to the theoretically predicted value for an ideal gold surf ace .
Measurements to determine emitted and reflected radiation power were made using the set-up shown in FIGS.
12A and 12B. In the tip mea2,uLe ~s the central ray of the reflected beam was deviated 112 degree6 from the parent f iber axis, and impacted the circular detector surface at its center. The central ray o~ the emerging beam was aligned in similar fashion relative to the detector f'or meaDu~ ~ ~s on bare f ibers .
Mea,,ul. ~s to determine the uniformity of reflected power from tipped fibers and of emitted power from the bare f ibers respectively, were made at constant input using the Nd:YAG la6er power settings of 5, 10 and 20 watts. The distance from either reflecting or emitting surface was kept at 7 centimeters. This was done to keep the fixed qe -tl~ for mea-iuL~ ~ at all power levels selected without bleaching or burning the bl At~ n~d detector surface.
Experiments were also performed on three fibers randomly picked from the tipped fiber population in order to as6ess the efficiency or percentage of power reflected in comparison to the average emitted power of the bare fiber population. These measurements were made at 10 WO 93/03678 PCr/US92/06693 21~S77Q -16-watts input Nd: YAG laser power delivered to each f iber and with the fiber end located l centimeter from the detector surface 80 as to collect sensibly all the reflected beam pattern. Collection of the entire beam with this g~ l.Ly was established from the ~ nying measurements (described below) of radiation intensity over the ref lected beam .
Measurements of the uniformity of distribution of radiation intensity over the cross section of the ref lected and emitted beam prof iles were made on tipped 2nd bare fibers (two in each population) using the set-up of FIGS. 13~ and 13B. Light from a 5-milliwatt helium neon laser (632.8 nanometers) was used.
A Coherent Radiation, Inc. Model 210 laser power meter and detector (25 mm aperture) was used for all mea~uL ~8 of the Nd:YAG laser beam power emitted from either the bare or the tipped f ibers . A United Detector Technologies silicon diode based 81 optometer detector was used to measure the angular distribution of the emitted helium neon beam (632.8 nanometers) for each fiber type.
Mea2.uL~ 1_8 of laser power emitted by groups of nine each bare and tipped flbers were made under identical conditions of 5, 10 and 20 watts input Nd:YAG laser power.
A seven centimeter distance between f iber end or tip and detector was maintained for all meaa~L~ 1_,,. Values of average power lmd standard deviation for both bare and tipped f ibers f or the three dif f erent input Nd: YAG laser powers are found in the following Table 1.
WO 93/0367~ 2 1 1 5 7 7 ~ PCr/US92/06693 TA~3LE 1 Measured Nd: YAG Laser Power Values From Bare and Tipped Fibers Laser Power Sett i nrrc ~Are Fi hPr ~i~ed FihF~r DisrAn~P
(w)(w) (w) (cm) 5 4 . 62 + 0. 29'b 3 . 36 + 0. 15 7 10 9 . 62 + 0 . 34 7 . 06 ~ 0 . 48 7 2018 . 17 + 0 . 68b 13 . 29 ~ 0 . 82 7 10 10 9.72 + 0.32 8.81 + 0.21' ' Numbers are average + standard deviation h n = 9 ' n = 3 As seen in Table 1 the bare fibers on the average emitted 92, 96 and 91 percent of the input laser power at 5, 10 and 20 watts. This clustering suggests reproducible light transmission by the parent fiber family.
Results f or the nine tipped f ibers in Table 1 show the strong uniformity of the percentage of reflected laser power. At laser input power values at 5, 10 and 20 watts, respectively, detected power values from the tipped fibers were nominally 73 percent (see Table 1) of the average power emitted from the bare tip of the parent fiber at each value of input laser power. This large difference arises from the reflected beam diameter ~YceeAin~ the detector ~e~ LuLe diameter at the 7 cm. detector to tip distance: thus only a fraction of the total reflected power was measured.
~0 93/03678 _ PCr/US92/06693 211~770 -18-In a subsequent experiment, the distance between the detector surface and the tip 12 was decreased to one centimeter. The detected average value of power emitted at lO watts of laser input from three tipped fibers was 8.8 plus or minus 0.21 watts. Light distribution analysis described bQlow ensured that at this one centimeter detector to reflecting tip surface distance that essentially 100 percent of the reflected light was collected by the detector. Relative to the average emitted power of the bare fiber family (9.72 plus or minus 0.32 watts) at 10 watts input the tipped fiber emits approximately 92 plus percent of the power emitted by the bare tip onto the gold reflecting surface. Allowing for about 98 percent theoretical reflectivity of the pure gold surface and the possibility of two or more multiple reflections from the rollqhnF~cc of a real production gold 6urf ace and thc non-zero standard deviations associated with the experimentally determined average values of power emitted by both bare and tipped fibers, actual differences 2 0 between bare f iber and ref lected power values can be considered to be negligibly small and the bare f iber and tipped f ibers can be considered to emit essentially equal power values at equal Nd:YAG laser input values.
Light distributions from EIe-Ne neon laser light (632.8 nm. ) were determined for representative bare fiber and tipped f ibers (two types each) . The average distributions are shown in FIG. 14. Examination of these f igures shows a spread of the beam f rom the bare f iber ~ WO 93/03678 2 1 1 !~ ~ 7 o Pcr/us92/o6693 upon ref lection in the tip 12 . This undoubtedly arises from a small diffuse scattering: t due to surface irregularities on the real gold surface. This scattering 5preads the beam from the tip 12 in essentially ,jy ical fashion about the central ray. The significant effect of reflection of the beam from the fiber end 31 is one of widening without introduction of relatively more or less intense regions of light that is hot or cold spots within the bell-shaped light pattern emitted by the bare tip fiber. Therefore, the shape of the bare fiber beam and that of the reflected side directed beam from tip 12 are essentially equivalent.
Integration of the light f lux emitted by both f iber tips over the detector aperture gives the total power incident upon the detector. The flux integral P is given by:
P5 D--zPoJ ~(~, COS'~rdr where P0 is the total light power emitted by the tips, F
(~) is the angular variation in the light intensity, and r is the radial distance on the surface of the detector of 2 0 aperture radius rO . The geometry is shown in FIGS . 12A
and 12B. Percentage values of the integral for various detector ~e~ l u-e:S are shown in FIG. 15 for both bare and tipped fibers. Performance of the integration for the tipped f iber placed 7 and 1 centimeters, respectively, away from the detector surface gives P = 0 . 717 and 1. 0 x the emitted power, respectively. These values are WO 93/03678 PCr/US92/06693 21~L577~ -20-consistent with average values measured at di~itances of 7 and 1 cm. of, respectively, 0.73 and 0.91 x the average power emitted by the bare f iber upon the ref lecting surfnce 38 of tip 12. Since light back scattering decreases as wavelength increases relative to scatterer sizes going about as one divided by wavelength raised to the nth power (n typically between 1 and 4), the width of the light distribution at the 1. 06 micron Nd:YAG
wavelength ref lected from the tip 12 is expected to be slightly smaller than the measured distribution at 632 . 8 nanometers .
Values of the fraction of total laser power contained within the beam as angle increases (radial distance increases) are plotted in FIG. 15 for both the bare and tipped f lbers . Use of these plots shows that ~1 minus exp(-2) ) of the total power within the beam from the bare f iber end and the tip 12 is contained within 5 and 16 degrees, respectively, of the central ray of the light distribution. As the result of the wider nature of beam from tip 12 equal spot sizes of radius R. tissue are achieved with the respective bare and tipped f ibers held at different distances D. from the tissue surface. Eior various spot sizes R. in the range of 1 to 4 mi l l i - ~ers, the associated values of the distance to tissue are tabulated in the following Table 2.
WO 93/03678 2 1 1 ~ 7 7 o Pcr/US92/06693 Spot Size and Distance Values for Bare and Tipped Fibers R" ~o D Fiber Type (mm) (deg) (cm) 5 1.14 Bare 16 0 . 35 Tipped 2 5 2 . 28 Bare 2 16 0 . 70 Tipped lo 4 5 4 . 56 Bare 4 16 1. 40 Tipped Tan ~0 = Ro/Do 15 The results of optical property Acce- ~s on the tip 12 and the bare fibers allow the following essential equivalences to be identified:
(1) Output beams of both tips are c~rlL~ay - LLic with respect to the central ray of peak intensity with uniform gradual fall off in intensity with radius in all directions.
Essentially no random hot or cold spots are present .
(2) The tip 12 reflects essentially all (91 + %) incident laser beam energy. Power densities at tissue equal to that of equivalent bare f iber can be achieved with the use of tip 12 by adjusting the tip to tissue distance, thus WO 93/03678 PCr/US92/066 adjusting spot size.
( 3 ) The essential action of the tip 12 is to reflect the laser beam laterally.
The substantially complete reflectivity of the gold mirror surface 38 also means that there is no clinically significant heating of the tip 12 itself, i.e., the tip 12 does not become sufficiently hot to significantly affect the tissue being treated if the tip 12 is placed in contact with the tissue but is oriented so that the reflected light beam does not fall upon the tissue contacted by the tip. This is shown by the following examp le .
E2~a~LE
The depths of coagulation achieved by using the tip 12 as a contact heating probe (no direct irradiation) and by directly irradiating tissue (no direct contact) were compared using 60 W of Nd: YAG laser power. Bovine liver (in vitro) was used as the test tissue. The arrangement for each experiment with the tip 12 is shown in FIGS. 16 and 17. The di6tance of tip 12 from the tissue is 4 mm in FIG. 16 which gives a spot size approximately equal to the 2 . 2 mm diameter contact size in FIG. 17 . In FIG. 6 the tip 12 is; ~ed in water 206 in a beaker 204. The test tissue 200 is placed against one side of the beaker.
After ~.~oauL~ for one minute with 60 W laser input power, surface bleaching of the liver color was noted at both the contact and irradiated sites. In FIG. 16 the WO 93/03678 = 2 1 1 ~ 7 7 ~ PCr~US9~/06693 bleached spot is indicated at 2 02 . Perpendicular sections cut with a scalpel through each bleached spot disclosed coagulation bleaching to extend to depth of approximately 700 micron ~ 0 . 7 mm) and 7 ~mm at the contacted and irradiated sites, respectively. Thus, direct exposure to the laser beam as opposed to only heating the tip ( in contact only with tissue) with the beam resulted in a 10-fold deeper coagulation depth and a 10-fold greater coagulation ef f iciency at equal exposure times .
lo Thus it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred r~mhorlir~~~s of the invention have been illustrated and described for ~u~oses of the present disclosure, numerous changes may be made by those skilled in the art which changes are ~ ~-csod within the scope and spirit o~ the present invention as def ined by the ~rp~n~ cl claims
Many medical procedures ut;li~;n~ such tips are more easily accomplished if the laser energy is reflected laterally from the longitudinal axis of the fiber 60 that it can be directed upon tissue which would be difficult to treat with light emitted axially from the fiber.
rv Of The Tnvention ~-3 o The present invention provides a number of improvements in the construction of tips of the type generally described.
First, an; ~vt:d mounting construction ~5 provided WO 93/03678 - ' PCr/US9Z/06 2~1~770 -2- 69~
whereby the tip i8 easily and securely attached to the flexible elongated light transmitting fiber. In thi6 c~mh~ the invention provides an elongated body having a distal head portion and having a plurality of f lexible legs extending proximally from the head portion. A
clamping means is operably associated with the body for urging the legs radially inward to clamp the distal end portion o~ the fiber between the legs. This is preferably provided by a two-piece tip wherein the f irst piece includes the f lexible legs which have outer surfaces thereon which define a conically tapered outer suriace of the ~irst piece. The second piece includes a sleeve slidably received about the legs. The sleeve includes a conically tapered inner surface complementary to the conically tapered outer surface so that when the sleeve slides over the legs ~ngA, ort o~ the conically tapered inner surface of the sleeve with the c~nioAl ly tapered outer surface of the legs causes the legs to be biased radially inward to clamp the distal end portion of the 2 0 f iber therebetween . This mounting arrangement is use~ul on a variety of tip de6igns and is not limited to laterally transmitting tips.
In another aspect of the invention a laterally ref lecting tip is provided which ref lects 6ubstantially all incident laser light energy laterally outward through an aperture so that there is no cl;n;cAlly significant heating of the tip. The tip includes an elongated thin cylindrical body having a fiber receiving longitudinal opening therein for receiving the distal end portion of the fiber. The body has a lateral passAgeway defined diametrically therethrough and intersecting the longitudinal opening. A reflecting mirror surface means is defined on the body for reflecting light from the fiber laterally outward through the lateral passageway. The lateral passageway being cl; F~pO5~ diametrically through the body provides a f lushing means f or permitting surrounding fluid to flow through the lateral pA~a~eway across the reflecting mirror surface to reduce collection WO 93/03678 2 ~ 1 5 7 7 ~ Pcr/us92/o669~
Or contaminants on the reflecting mirror surface.
In another aspect of the invention an;, ~uv~d method i6 provided for forming a light reflecting mirror surface on a laterally reflecting tip. This is accomplished by providing a gold reflecting surface on the tip, and coining the gold reflecting surface to provide a superior ref lecting surf ace .
In yet another aspect of the invention a method is provided for forming a light reflecting mirror surface on lo a laterally reflecting tip. First a tip body is formed from a first metal other than gold. An underlying gold layer is then sputter deposited on the body. Finally an outer gold sheet is diffusion bonded under external pressure at elevated temperature to the underlying gold layer, with the outer surface of the outer gold sheet defining the light reflecting mirror surface. Preferably this light reflecting mirror surface is then coined to provide a superior reflecting surface.
Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the ~: , ~nying drawings .
Brief lm~ ri~tion Of The Drawinrlc FIG. 1 is a plan view of the light reflecting tip assembled with a f lexible elongated light transmitting f iber .
FIG. 2 i6 an elevation 6ectioned view taken along line 2-2 of FIG. 1.
FIG. 3 is a plan view similar to FIG. 1 of the elongated body of the two-piece tip assembly of FIGS. 1 and 2.
FIG. 4 is an elevation sectioned view of the body of FIG. 3 taken along line 4-4.
FIG. 5 is a right end view of the body of FIG. 4.
FIG. 6 is an elevation sectioned view of the sleeve piece of the two-piece tip assembly of FIGS. 1 and 2.
WO 93/03678 PCT/US92/0669,~
7 0 _4_ FIG. 7 is a schematic illustration similar to FIG. 2 showing the beam spread of a beam ref lected from a f lat mirror .
FIG. 8 i5 a view similar to FIG. 7 showing the beam spread of a beam ref lected f rom a concave mirror .
FIG. g is a view similar to FIG. 7 showing the beam spread of a beam ref lected f rom a convex mirror .
FIG. lo is ~ schematic illustration of the laser and ~ul~score with which the f iber and tip are u3ed .
FIG. 11 is an enlarged sectioned view of a portion of the ~ndc:,scu~ic tube of FIG. lO, illustrating the passage of the f iber and tip through a curved ~n~ scopic tube.
FIGS. 12A and ~3 and 13A and B schematically represent certain tests which were run to ~lPt~m;n~ reflective ef f iciency of the tips .
FIGS. 14 and 15 are graphic representations of the spreading of the light beam energy by a f lat ref lective mirror surf ace .
FIGS. 16 and 17 schematically illustrate the methodology of an example test which shows that there is no clinically signif icant heating of the tip .
Det~ 3escri~tion Of The Preferred F~hodiments Ref erring now to the drawings, and particularly to FIGS . 1 and Z, a tip and f iber assembly is thereshown and generally designated by the numeral 10. The assembly 10 includes a two-piece light reflecting tip 12 mounted upon a distal end portion 14 of a f lexible elongated light transmitting f iber 16 .
The two-piece tip 12 includes an elongated body 18 3 o which is best shown in isolation in FIGS . 3 -5 and a clamping sleeve 20 which is illustrated in isolation in FIG. 6.
The f iber 16 is a commercially available laser light transmitting f iber . Such f ibers include a f lexible elongated cylindrical core 22 which is ~uL~uullded by a rl;~tlr~;n~ of lower optical refractive index material which is overlain with an outer protective jacket. As seen in ~ W093/03678 2I1~770 PCr/[JS92/06693 FIG. 2, when assembled with the tip of the present invention, the outer rlA~ in~ and ~acket of the fiber 16 are preferably trimmed back to end at 23 with the fiber core 22 extending distally beyond the end 23 of the outer protective layers. Thi6 m;nirni zo- the pos6ibility of burning of the outer protective layers due to laser energy ref lected back f rom the mirror surf ace .
The elongated body 18 ha6 a distal head portion 24 and has first and second flexible legs 26 and 28 extending proximally from the head portion 24. Although there is no critical line of distinction between the head portion 24 and the legs 26 and 28, the head portion 24 can generally be described as having a lcngth 25 as seen in FIG. 3, and the legs 26 and 28 can generally be described as having a length 27. Head portion 24 has a squared-off flat end 21.
As used herein the terms distal and proximal are used in relation to the terminology generally used for the fiber 16 with the distal end of fiber 16 being indicated at 31 in FIG. 2, and with the proximal end of the fiber 16 being the other end which typically would be attached to the laser light source 108 (6ee FIG. 10). Thus the distal and proximal directions or relative orientations are provided for the tip 12 used in association with the fiber 16 .
The clamping sleeve 20 can be more generally described as a clamping means 20 operably associated with the body 18 for urging the legs 26 and 28 radially inward to clamp the distal end portion 14 of fiber 16 therebetween in a manner further described below.
As best seen in FIG. 4, a blind bore 30 is drilled into the proximal end 32 of body 18 thus defining partially cylindrical inner surfaces 34 and 36 on legs 26 and 28, respectively, which surfaces 34 and 36 define a body bore means 30 for closely receiving and clamping the distal end portion 14 of the fiber 16 therebetween.
The body 18 can be described as having a plurality of legs, which in the preferred ~-';r- t are two and only two legs 26 and 28. The head portion 24 has 2 reflecting WO 93/03678 PCr/US92/0669jl~
2115~70 -6-mirror surface means 38 defined thereon for reflecting light emitted from the di6tal end 31 o~ fiher 16 laterally outward. The body bore means 30 terminates short of the ref lecting mirror surf ace 3 8 .
S The legs 26 and 28 have proximal cr~n;cAlly tapered outer 6urface portions 40 and 42, respectively, which collectively define a conically tapered outer body 6urface 44 extending over a length 46.
A di6tal portion 48 of legs 26 and 28 defines a generally cylindrical outer surface 50 having f irst and second annular radially outward extending flanges 52 and 54 each of which has a distally facing shoulder 56 and 58, respectively, defined thereon.
The body 18 is preferably formed from a cylindrical stainless steel blanlc which is machined to have the appearance shown in FIGS. 3 and 4. The lateral pACc~geway 88 and legs 26 and 28 are partially formed by milling a slot having the width 39 as seen in FIG. 3 into the cylindrical blank. As further described below, the body 18 may also be formed of solid gold in which case it will be cast in the shape shown in FIGS. 3 and 4.
The clamping sleeve 20 which is shown in its ~nAcc~l-hled state in FIG. 6, is designed to be slidably received about the legs 26 and 28. Clamping sleeve 20 has an axial sleeve bore 60 defined through its proximal end 62 for closely receiving the fiber 16. Clamping sleeve 20 further includes a tapered conical sleeve counterbore 64 complementary to the conically tapered outer body surface 44 so that when the clamping sleeve 20 slides in a distal direction over the legs 26 and 28, engagement of the tapered conical sleeve counterbore 64 with the C~ i CA l l y tapered outer body surface 44, causes the legs 26 and 28 to be biased radially inwardly.
The clamping sleeve 20 further includes a thin cylindrical distal portion 66 and a thin cylindrical proximal portion 68 which as further described below are used in securing the two-piece tip assembly together and onto the f iber 16 .
~ WO 93~03678 ~ i 7 7 0 PCr/US92/06693 _ 7 _ As best seen in FIG . 2, a body abutment surf ace 7 0, which is an annular shoulder, is defined on the head 24 of body 18. A 61eeve abutment surface 72, which is the distal end of sleeve 20, is defined on the clamping sleeve 20 and is arranged to abut the body abutment surface 70 to limit sliding motion of the clamping sleeve 20 over the legs 26 and 28.
The tapered conical sleeve counterbore 64 and the conically tapered outer body surface 44 have an interference fit prior to abutment of the sleeve abutment surface 72 with the body abutment surface 70. Thus, with the fiber 16 in place as shown in FIG. 2, a6 the clamping sleeve 20 slides distally over the legs 26 and 28, the 61iding interference fit between tapered surfaces 64 and 44 causes the legs 26 and 28 to be cammed radially inward thus clamping f iber 16 therebetween .
After the sleeve abutment surface 72 engages the body abutment surface 70, the clamping sleeve 20 is secured to the body 18 by forming first and second circumferentially rolled crimps 74 and 76 in the thin cylindrical distal portion 66 of clamping sleeve 20 so that the crimps 74 and 76 engage the annular shoulders 56 and 58 to prevent the clamping sleeve 20 from sliding backwards off the legs 26 and 28. Additionally, the thin cylindrical proximal portion 68 of clamping sleeve 20 is further secured to the fiber 16 by t9;; L~lcally opposed staking crimps 78 and 80 as seen in FIG. 1.
It will be appreciated that the construction of the legs and clamping sleeve could be reversed so that the sleeve protrudes from the body with the legs being formed on a separate piece which slides into engagement with the sleeve. More generally, the tip 12 can be described as a two-piece tip including a first piece having a plurality of longitll~ i n;~ 1 1 y extending legs and a second piece in~ 9;n~ a sleeve slidably received about the legs.
The abutment surfaces 70 and 72 can be more generally described as a limit means 70, 72 for limiting insertion of the legs 26 and 28 within the clamping 61eeve 20 and WO 93~03678 ~ PCr/US92/066 ~ 770 ~\
thereby limiting a clamping force applied to the fiber 16 by the legs 26 and 28.
It i8 noted that the body 18 shown in FIG . 4 dif f ers in one aspect from the body 18 illustrated in FIG. 2, namely in regard to the construction of the ref lecting mirror surf acQ means 3 8 .
The reflecting mirror surface means 38 is preferably made of bi o _ ~tible 99 . g+ percent gold. This can be accomplished in at least two ways. In FIG. 4, the entire body 18 is made from gold and thus all that need be done to compLete the reflecting mirror surface mean6 38 is to treat the sur~ace to make it as smooth and ref lective as possible .
FIG. 2, on the other hand, illustrates a construction wherein the major portion of the body 18 is made of a first metal other than gold, preferably 316 st~inless ~teel. An underlying mirror support surface 82 is defined on this f irst material . Then gold is laid over the underlying support surf ace in 6uch a way as to f orm the gold reflecting mirror surface means 38. One preferred manner of doing this is to sputter deposit an underlying gold layer 84 onto the underlying mirror support surface 82, and then to diffusion bond a gold sheet 86 to the underlying gold layer 84.
The diffusion bonded gold sheet 86 preferably is formed from rectangular gold wire having a thickness of at least 0 . 014 inches thus providing a gold layer thick enough to prevent the chemical action of the ~iurL~ullding saline medium from corroding completely through the gold layer during typical medical treatment procedures. The gold sheet has a width approximately equal to the width 39 of mirror 6urface 38.
Regardless of whether the solid gold body of FIG. 4 or the stainless steel body with overlying gold layers of FIG. 2 is used, the final treatment of the gold reflecting mirror surface means 38 is preferably formed by coining the surf ace . Coining is a mechanical process whereby a very hard, ~mooth member is pressed against the surface 38 _ ~ WO 93/03678 2 i 1 5 7 7 o Pcr/us92/o6693 g to stamp it or coin it so that it too carries a smooth highly reflective impression.
As is further described below, the smooth, coined, gold reflecting mirror surface means 38 provides a means for reflecting substantially all of the light energy incident thereon from the fiber 16.
Alternatively, the mirror surface 38 could be made smooth by electro or -~ ~nic~l polishing or by chemical etching .
In designing a tip for maximum reflection so that substantially all laser light energy incident upon the reflecting surface 38 is reflected, it is n-~r^~r~ry to choose the reflecting material ~er~n~nt upon the particular laser being utilized . Dif f erent ref lective materials have more efficient reflective characteristics for different wavelengths of laser light. For example, when utilizing an Nd:YAG laser having a characteristic wavelength of 1064 or 1318 nanometers, or when using a Ho:YAG laser having a characteristic wavelength of 2100 nanometers, the reflective surface 38 is preferably made of gold.
On the other hand, for a frequency doubled Nd:YAG
laser having characteristic wavelengths of 532 or 659 nanometers, a platinum surface 38 i5 preferred.
Similarly, the platinum surface is preferred for an Alexandrite laser having a 680-800 nanometer tuning range, a Sapphire laser having a 680-800 nanometer tuning range, an Argon Ion laser emitting radiation with wavelengths in the 428-528 nanometer range, and for a dye laser having a 400-800 nanometer tuning range.
Gold and platinum are chosen as preferred mirror surfaces on the basis of their high optical reflectivities and their relative stabilities in a warm aqueous saline solution environment.
As is best seen in FIG. 2, the body 18 has a lateral p~csz~eway 88 defined .1; L,ically therethrough which intersects the body bore means 30. The lateral passageway 88 has diametrically opposite first and second end WO 93/03678 PCr/US92/06693 2~770 - ~
openings 9o and 92, respectively. The lateral passageway 88 extends across and runs parallel to the ref lecting mirror surface means 38, and thus due to the slope of the re1ecting mirror surface means 38, the second end opening 92 is substanti~lly smaller than the first end opening 90 of lateral passageway 88. .
The reflecting mirror surface means 38 is set at an angle 94 to the longitudinal axis 96 of the f iber 16 and tip 12 . Thus light exiting the dist~ 1 end 31 of f iber lo core 22 falls axially (with a small divt:r ~ence) onto the reflecting mirror surface means 38 and then is reflected laterally out the larger first end opening 90 of lateral passageway 88.
There is some angular diffusion of the light which reflects from the reflecting mirror surface means 38 80 that it tends to difuse into a conical beam, and the body 38 has a conical cavity 98 superimposed upon the larger first end opening 90 of lateral pas6ageway 88 thus permitting the ref lected beam to pass laterally outward 2 0 without impinging upon any other portions of the tip 12 other than the reflecting mirror surface means 38.
The tip 12 is constructed for usage in any number of medical ~Lu~eduLes wherein the tip is used to direct laser light onto human tissue to treat the same. The tip 12 is typically immersed in an aqueous saline solution dLuring operat$on, but it will be appreciated that often the solution is contaminated with proteins from the surrounding body tissue. If these proteins are allowed to build up on the reflecting mirror surface means 38, it of course will significantly degrade the operation of the tip 12. The lateral passageway 88 extending completely laterally through the body 18 over the ref lecting mirror surface means 38 provides a flushing means 88 for permitting ~uLLuu,ding fluid, typically saline solution, to flow in one of the first and second end op~nin~c 90 and 92, then across the reflecting mirror surface means 38, then out the other of the f irst and second end openings, thus tending to cleanse the ref lecting mirror surf ace WO 93/03678 2 1 1 ~ 7 7 0 means 38 and to reduce collection of contaminants on the ref lecting mirror surf ace means 3 8 .
The flushing of saline solution through the lateral p;-CCa~Pway 88 also aids in carrying away saline solution heated by laser light passing therethrough to prevent any . significant heat buildup adjacent the tip 12. As further shown below, the tip 12 is designed for substantially complete reflection of the laser light energy incident upon mirror 38. There is no clinically significant heating of tip 12.
FIGS. 7-9 are somewhat simplified versions of FIG. 2 and they illustrate various modifications that can be made to the reflecting mirror surface means 38.
FIG. 7 Lllustrates the flat planar reflecting mirror surface means 38 previously described with regard to FIGS.
2 and 4. In a preferred ~ the angle 94 of surface 38 is 373~, and the distal end 31 of fiber core 22 is cut square, i.e., it defines a plane normal to the axis 9 6 of the f iber . With such an arrangement, and with a highly reflective coined gold reflecting mirror surface means 38, the reflected beam 100, the outer extremities of which are shown in phantom lines will diverge slightly from a cylindrical beam due to divergence upon exiting fiber core 22 and due to imperfect reflection of the mirrored surface 38 so as to form a reflected light spot 102. In a preferred ~ nt the flat coined gold reflecting mirror surface means 38 of FIG. 7 is a means for providing a generally circular reflected light spot size 102 no greater than 3 mm diameter at a distance of 1. 05 cm along the central ray of the deflected beam from the central axis 96 of the fiber 16.
It is noted that with the specified angle 94, the reflected beam will reflect somewhat in a proximal direction. This back reflection is a significant aid in directing the reflected beam to hard-to-reach portions of cavities within the human body. The angle of reflection of the beam can of course be modified as desired by modifying the angle 94 and the conf iquration of the WO 93/03678 ~ PCr/US92/0669~
211~770 reflecting surface 38. Also, the distal end 31 o~ the f iber core 22 can be cut at an angle which will also affect the dispersion and direction of the light beam emitted theref rom .
A6 best seen in FIG. 2, there i5 an axial clearance between the distal end 31 of fiber core 32 and the reîlecting mirror surf~ce means 38. This permits the lo .. . - ~ ref lected beam to exit through the lateral p~C6~qP~ay 88 without impinging upon the fiber end 31 or any portion of the tip 12 other than the mirror 38.
DPrDn~l;n~ upon the type of treatment being conducted, it may be desirable for the reflected light spot 102 to be either more diffused or more cul.c~ L~lLed. This can be accomplished by modifying the reflecting mirror surface means 38 as shown in FIGS. 8 or 9 to U~ L~te or disperse the beam, respectively.
In FIG. 8, the reflecting mirror surface means 38 has a concave portion 104 which is impinged by the beam from fiber core 22 thus cullc~ Lc~ing the rPflertecl beam lOOA
to form a smaller reflected beam spot 102A as compared to FIG. 7.
In FIG. 9, the reflecting mirror surface means 38 includes a convex portion 106 which causes the reflected beam lOOB to be more dispersed and thus form a larger reflected beam spot 102B as compared to the apparatus of FIG . 7 .
Tt will be appreciated that FIGS. 7-9 are only schematically illustrated and are not nDcPcc~rily geometrically correct. The angles of the beams have been somewhat exaggerated to illustrate the difference between the various Dmhorl i ~5 .
FIG. 10 schematically illustrates the various apparatus with which the fiber 16 and tip 12 are typically used . The proximal end of the f iber 16 is connected to a laser 108 which produces the laser light which i5 trzmsmitted through the fiber 16 and then reflected by tip 12. In the pre5ent disclosure the word light is used in its broad sense, me~ning ele~ netic radiation which ~ WO 93/03678 2 1 1 ~ 7 7 0 PCr/US92/06693 propagates through space and include6 not only visible light, but also infrared, ultraviolet and microwave radiation. In the preferred ~ ';r~nt, the light transmitted by fiber 16 is laser light ~Loduc~d by the laser 108.
The fiber 16 is typically utilized with a conventional Pn~ scope 116, which may be rigid or flexible, and which carries the fiber 16 in a cylindrical passage 118 defined in an Pn~loficopic tube 120. The Pn~-6copic tube 120 may include a parallel optical viewing fiber (not shown) and parallel fluid flow conduits (not shown). Also, the cylindrical passage 118 may itself be utilized as a fluid flow passage to allow irrigating f luids to f low to the tip 12 .
It will be appreciated that tlprpn~l;n~ upon the medical procedure being performed, the endoscopic tube typically may need to pass through various curved cavities in the human body so as to reach the area to be treated.
In such case a flexible Pn~ ccope will be used.
The tip 12 and fiber 16 which are assembled according to the present invention pref erably are constructed so that they can pass through the cylindrical passage 118 of endoscopic tube 120 when the endoscopic tube 120 is contorted in the necessary fashion. Thus, the fiber 16 assembred with tip 12 must be capable of curving to pass through the curved cylindrical passage 118. Also, the fiber 16 and tip 12 must pass through the ~ &r~e 116 itself. Typically the most severe ~,ULVC~I_ULt: through which the f iber 16 and tip 12 must pa2~;s is the bend at connection 117 where the ~iber 16 enters the Pn~ scope 116 from a laterally offset position and then must pass into the tube 120. The radius of ~:ULVe~LULe of this bend on existing Pn~lc scopP~ is approximately lo cm. This passage may have a diameter on existing Pn~scop~c as small as 2.5 mm.
FIG. 11 is a schematic, 5egmented, cross-section portion of the endoscopic tube 120 in the curved area designated in FIG. 10. The fiber 16 and tip 12 are shown WO 93/03678 PCr/US92/06693 211~77~ -14-in phantom lines in FIG. 11 as they would appear when the tip 12 and f iber 16 are being run in a distal direction through the pasGage 118 80 that they ultimately will extend from the distal end of endo6copic tube 120 as illustrated in FIG. 10.
A typical passage 118 of available ~n~- scopic tubes 120 has a diameter of no greater than 2 . 5 mm. The preferred optical fiber described below has a design minimum bending radius of 1 cm which can easily conform to passage 118 50 long as the tip 112 can f it through the curved passage. Since the most severe bend to be encountered is that at junction 117, the fiber 16 and tip 12 should be 50 constructed and dimensioned A5 to provide an assembly capable of passing through a curved cylindrical passage having a diameter of 2 . 5 mm and a radius of ~uLv~Lu-e of 10 cm.
Prior art tip constructions for laterally reflecting tips have been relatively bulky and have been incapable of passing through such a narrow curved passage. The present invention has solved this problem. In a preferred ~mho~l;r L this is accomplished by ~ullaLLu~;Ling the tip 12 to have a length 122 (see FIG. 1) of 0 . 3543 inches (9 . 000 mm) and an outside diameter 124 of 0 . 0866 inches (2 . 200 mm). This tip is generally cylindrical in shape and is concentrically mounted upon the distal end portion 14 of fiber 16. Prcferably the tip 12 has a maximum diameter 124 of no greater than 2 . 2 mm, and a length no greater than 1 cm.
The preferred light transmitting fiber 16 for use with the tip 12 having the dimensions just described is a conventional fused silica fiber. This fiber has a minimum bending radius of 1 cm. The silica core has a diameter of 600 microns and the fiber with cladding has an outside diameter of 0.040 inch which is clamped within the bore 30 3 5 of tip 12 which has a bore diameter of 0 . 04 0 inches .
In this pref erred embodiment the tapered outer surface 44 and tapered inner counterbore 64 have an angle of taper such as indicated at 126 in FIG. 3 in the range ~ WO 93/03678 2 1 1 ~ 7 ~ ~ PCr/us92/o6693 of from 4.2 to 4.8O.
EfficiencY of Reflection Mea~u, ~ ~s of reflective optical power and intensity distribution over the ref lected beam were made on a group of nine f ibers having tips 12 with 99 . 9% gold reflective surface formed as dcscribed above with regard to FIG. 2. Similar measurements were also made on a COr r ~ v~ n~ group of bare fibers of identical manuf acture .
Specifically, measurements were made to assess and compare the ~é~ /ducibility of values of reflected and emitted power and radiated intensity di6tribution within each group of optical fibers and to compare the efficiency of the reflection by the actual gold surface relative to the theoretically predicted value for an ideal gold surf ace .
Measurements to determine emitted and reflected radiation power were made using the set-up shown in FIGS.
12A and 12B. In the tip mea2,uLe ~s the central ray of the reflected beam was deviated 112 degree6 from the parent f iber axis, and impacted the circular detector surface at its center. The central ray o~ the emerging beam was aligned in similar fashion relative to the detector f'or meaDu~ ~ ~s on bare f ibers .
Mea,,ul. ~s to determine the uniformity of reflected power from tipped fibers and of emitted power from the bare f ibers respectively, were made at constant input using the Nd:YAG la6er power settings of 5, 10 and 20 watts. The distance from either reflecting or emitting surface was kept at 7 centimeters. This was done to keep the fixed qe -tl~ for mea-iuL~ ~ at all power levels selected without bleaching or burning the bl At~ n~d detector surface.
Experiments were also performed on three fibers randomly picked from the tipped fiber population in order to as6ess the efficiency or percentage of power reflected in comparison to the average emitted power of the bare fiber population. These measurements were made at 10 WO 93/03678 PCr/US92/06693 21~S77Q -16-watts input Nd: YAG laser power delivered to each f iber and with the fiber end located l centimeter from the detector surface 80 as to collect sensibly all the reflected beam pattern. Collection of the entire beam with this g~ l.Ly was established from the ~ nying measurements (described below) of radiation intensity over the ref lected beam .
Measurements of the uniformity of distribution of radiation intensity over the cross section of the ref lected and emitted beam prof iles were made on tipped 2nd bare fibers (two in each population) using the set-up of FIGS. 13~ and 13B. Light from a 5-milliwatt helium neon laser (632.8 nanometers) was used.
A Coherent Radiation, Inc. Model 210 laser power meter and detector (25 mm aperture) was used for all mea~uL ~8 of the Nd:YAG laser beam power emitted from either the bare or the tipped f ibers . A United Detector Technologies silicon diode based 81 optometer detector was used to measure the angular distribution of the emitted helium neon beam (632.8 nanometers) for each fiber type.
Mea2.uL~ 1_8 of laser power emitted by groups of nine each bare and tipped flbers were made under identical conditions of 5, 10 and 20 watts input Nd:YAG laser power.
A seven centimeter distance between f iber end or tip and detector was maintained for all meaa~L~ 1_,,. Values of average power lmd standard deviation for both bare and tipped f ibers f or the three dif f erent input Nd: YAG laser powers are found in the following Table 1.
WO 93/0367~ 2 1 1 5 7 7 ~ PCr/US92/06693 TA~3LE 1 Measured Nd: YAG Laser Power Values From Bare and Tipped Fibers Laser Power Sett i nrrc ~Are Fi hPr ~i~ed FihF~r DisrAn~P
(w)(w) (w) (cm) 5 4 . 62 + 0. 29'b 3 . 36 + 0. 15 7 10 9 . 62 + 0 . 34 7 . 06 ~ 0 . 48 7 2018 . 17 + 0 . 68b 13 . 29 ~ 0 . 82 7 10 10 9.72 + 0.32 8.81 + 0.21' ' Numbers are average + standard deviation h n = 9 ' n = 3 As seen in Table 1 the bare fibers on the average emitted 92, 96 and 91 percent of the input laser power at 5, 10 and 20 watts. This clustering suggests reproducible light transmission by the parent fiber family.
Results f or the nine tipped f ibers in Table 1 show the strong uniformity of the percentage of reflected laser power. At laser input power values at 5, 10 and 20 watts, respectively, detected power values from the tipped fibers were nominally 73 percent (see Table 1) of the average power emitted from the bare tip of the parent fiber at each value of input laser power. This large difference arises from the reflected beam diameter ~YceeAin~ the detector ~e~ LuLe diameter at the 7 cm. detector to tip distance: thus only a fraction of the total reflected power was measured.
~0 93/03678 _ PCr/US92/06693 211~770 -18-In a subsequent experiment, the distance between the detector surface and the tip 12 was decreased to one centimeter. The detected average value of power emitted at lO watts of laser input from three tipped fibers was 8.8 plus or minus 0.21 watts. Light distribution analysis described bQlow ensured that at this one centimeter detector to reflecting tip surface distance that essentially 100 percent of the reflected light was collected by the detector. Relative to the average emitted power of the bare fiber family (9.72 plus or minus 0.32 watts) at 10 watts input the tipped fiber emits approximately 92 plus percent of the power emitted by the bare tip onto the gold reflecting surface. Allowing for about 98 percent theoretical reflectivity of the pure gold surface and the possibility of two or more multiple reflections from the rollqhnF~cc of a real production gold 6urf ace and thc non-zero standard deviations associated with the experimentally determined average values of power emitted by both bare and tipped fibers, actual differences 2 0 between bare f iber and ref lected power values can be considered to be negligibly small and the bare f iber and tipped f ibers can be considered to emit essentially equal power values at equal Nd:YAG laser input values.
Light distributions from EIe-Ne neon laser light (632.8 nm. ) were determined for representative bare fiber and tipped f ibers (two types each) . The average distributions are shown in FIG. 14. Examination of these f igures shows a spread of the beam f rom the bare f iber ~ WO 93/03678 2 1 1 !~ ~ 7 o Pcr/us92/o6693 upon ref lection in the tip 12 . This undoubtedly arises from a small diffuse scattering: t due to surface irregularities on the real gold surface. This scattering 5preads the beam from the tip 12 in essentially ,jy ical fashion about the central ray. The significant effect of reflection of the beam from the fiber end 31 is one of widening without introduction of relatively more or less intense regions of light that is hot or cold spots within the bell-shaped light pattern emitted by the bare tip fiber. Therefore, the shape of the bare fiber beam and that of the reflected side directed beam from tip 12 are essentially equivalent.
Integration of the light f lux emitted by both f iber tips over the detector aperture gives the total power incident upon the detector. The flux integral P is given by:
P5 D--zPoJ ~(~, COS'~rdr where P0 is the total light power emitted by the tips, F
(~) is the angular variation in the light intensity, and r is the radial distance on the surface of the detector of 2 0 aperture radius rO . The geometry is shown in FIGS . 12A
and 12B. Percentage values of the integral for various detector ~e~ l u-e:S are shown in FIG. 15 for both bare and tipped fibers. Performance of the integration for the tipped f iber placed 7 and 1 centimeters, respectively, away from the detector surface gives P = 0 . 717 and 1. 0 x the emitted power, respectively. These values are WO 93/03678 PCr/US92/06693 21~L577~ -20-consistent with average values measured at di~itances of 7 and 1 cm. of, respectively, 0.73 and 0.91 x the average power emitted by the bare f iber upon the ref lecting surfnce 38 of tip 12. Since light back scattering decreases as wavelength increases relative to scatterer sizes going about as one divided by wavelength raised to the nth power (n typically between 1 and 4), the width of the light distribution at the 1. 06 micron Nd:YAG
wavelength ref lected from the tip 12 is expected to be slightly smaller than the measured distribution at 632 . 8 nanometers .
Values of the fraction of total laser power contained within the beam as angle increases (radial distance increases) are plotted in FIG. 15 for both the bare and tipped f lbers . Use of these plots shows that ~1 minus exp(-2) ) of the total power within the beam from the bare f iber end and the tip 12 is contained within 5 and 16 degrees, respectively, of the central ray of the light distribution. As the result of the wider nature of beam from tip 12 equal spot sizes of radius R. tissue are achieved with the respective bare and tipped f ibers held at different distances D. from the tissue surface. Eior various spot sizes R. in the range of 1 to 4 mi l l i - ~ers, the associated values of the distance to tissue are tabulated in the following Table 2.
WO 93/03678 2 1 1 ~ 7 7 o Pcr/US92/06693 Spot Size and Distance Values for Bare and Tipped Fibers R" ~o D Fiber Type (mm) (deg) (cm) 5 1.14 Bare 16 0 . 35 Tipped 2 5 2 . 28 Bare 2 16 0 . 70 Tipped lo 4 5 4 . 56 Bare 4 16 1. 40 Tipped Tan ~0 = Ro/Do 15 The results of optical property Acce- ~s on the tip 12 and the bare fibers allow the following essential equivalences to be identified:
(1) Output beams of both tips are c~rlL~ay - LLic with respect to the central ray of peak intensity with uniform gradual fall off in intensity with radius in all directions.
Essentially no random hot or cold spots are present .
(2) The tip 12 reflects essentially all (91 + %) incident laser beam energy. Power densities at tissue equal to that of equivalent bare f iber can be achieved with the use of tip 12 by adjusting the tip to tissue distance, thus WO 93/03678 PCr/US92/066 adjusting spot size.
( 3 ) The essential action of the tip 12 is to reflect the laser beam laterally.
The substantially complete reflectivity of the gold mirror surface 38 also means that there is no clinically significant heating of the tip 12 itself, i.e., the tip 12 does not become sufficiently hot to significantly affect the tissue being treated if the tip 12 is placed in contact with the tissue but is oriented so that the reflected light beam does not fall upon the tissue contacted by the tip. This is shown by the following examp le .
E2~a~LE
The depths of coagulation achieved by using the tip 12 as a contact heating probe (no direct irradiation) and by directly irradiating tissue (no direct contact) were compared using 60 W of Nd: YAG laser power. Bovine liver (in vitro) was used as the test tissue. The arrangement for each experiment with the tip 12 is shown in FIGS. 16 and 17. The di6tance of tip 12 from the tissue is 4 mm in FIG. 16 which gives a spot size approximately equal to the 2 . 2 mm diameter contact size in FIG. 17 . In FIG. 6 the tip 12 is; ~ed in water 206 in a beaker 204. The test tissue 200 is placed against one side of the beaker.
After ~.~oauL~ for one minute with 60 W laser input power, surface bleaching of the liver color was noted at both the contact and irradiated sites. In FIG. 16 the WO 93/03678 = 2 1 1 ~ 7 7 ~ PCr~US9~/06693 bleached spot is indicated at 2 02 . Perpendicular sections cut with a scalpel through each bleached spot disclosed coagulation bleaching to extend to depth of approximately 700 micron ~ 0 . 7 mm) and 7 ~mm at the contacted and irradiated sites, respectively. Thus, direct exposure to the laser beam as opposed to only heating the tip ( in contact only with tissue) with the beam resulted in a 10-fold deeper coagulation depth and a 10-fold greater coagulation ef f iciency at equal exposure times .
lo Thus it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred r~mhorlir~~~s of the invention have been illustrated and described for ~u~oses of the present disclosure, numerous changes may be made by those skilled in the art which changes are ~ ~-csod within the scope and spirit o~ the present invention as def ined by the ~rp~n~ cl claims
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An operating assembly for use in a liquid operating environment, comprising:
a flexible elongated light transmitting fiber having a distal end portion with a distal fiber end defined thereon; and a light reflecting tip attached to said distal end portion of said fiber, said tip including a reflecting mirror surface spaced from said distal fiber end and so arranged and constructed as to laterally reflect light exiting said distal fiber end, said tip having a flushing passageway defined therein between said distal fiber end and said reflecting mirror surface so that surrounding liquid from said liquid operating environment may pass through said flushing passageway to carry away from said tip liquid heated by light passing from said distal fiber end to said reflecting mirror surface, said flushing passageway being free from communication with any source of flushing fluid other than said surrounding liquid from said liquid operating environment.
a flexible elongated light transmitting fiber having a distal end portion with a distal fiber end defined thereon; and a light reflecting tip attached to said distal end portion of said fiber, said tip including a reflecting mirror surface spaced from said distal fiber end and so arranged and constructed as to laterally reflect light exiting said distal fiber end, said tip having a flushing passageway defined therein between said distal fiber end and said reflecting mirror surface so that surrounding liquid from said liquid operating environment may pass through said flushing passageway to carry away from said tip liquid heated by light passing from said distal fiber end to said reflecting mirror surface, said flushing passageway being free from communication with any source of flushing fluid other than said surrounding liquid from said liquid operating environment.
2. The assembly of claim 1, wherein said reflecting mirror surface is constructed to reflect substantially all light falling thereon.
3. The assembly of claim 2, wherein said reflecting mirror surface and said flushing passageway comprise a means for preventing any clinically significant heating of said tip.
4. The assembly of claim 1, wherein:
said flushing passageway extends laterally through said tip and has laterally opposite first and second flushing passageway end openings, so that said liquid passing through said flushing passageway flows in one of said first and second flushing passageway end openings and out the other of said flushing passageway end openings.
said flushing passageway extends laterally through said tip and has laterally opposite first and second flushing passageway end openings, so that said liquid passing through said flushing passageway flows in one of said first and second flushing passageway end openings and out the other of said flushing passageway end openings.
5. The assembly of claim 4, wherein:
said tip is generally cylindrical in shape; and said flushing passageway extends diametrically through said tip.
said tip is generally cylindrical in shape; and said flushing passageway extends diametrically through said tip.
6. The assembly of claim 1, wherein:
said tip is free from attachment to any structure other than said fiber.
said tip is free from attachment to any structure other than said fiber.
7. The assembly of claim 1, wherein:
said fiber includes a core, a cladding surrounding said core, and an outer protective jacket surrounding said cladding;
said tip includes a hollow crimping cylinder extending proximally therefrom;
said tip and said hollow crimping cylinder have a tip body bore defined therein from a proximal end of said hollow crimping cylinder, said distal end portion of said fiber being received in said tip body bore; and said tip includes at least one crimp in said crimping cylinder, said crimp mechanically attaching said tip to said outer protective jacket of said fiber.
said fiber includes a core, a cladding surrounding said core, and an outer protective jacket surrounding said cladding;
said tip includes a hollow crimping cylinder extending proximally therefrom;
said tip and said hollow crimping cylinder have a tip body bore defined therein from a proximal end of said hollow crimping cylinder, said distal end portion of said fiber being received in said tip body bore; and said tip includes at least one crimp in said crimping cylinder, said crimp mechanically attaching said tip to said outer protective jacket of said fiber.
8. The apparatus of claim 1, wherein:
said reflecting mirror surface is made of gold.
said reflecting mirror surface is made of gold.
9. The apparatus of claim 8, wherein:
said body is solid gold.
said body is solid gold.
10. The apparatus of claim 8, wherein:
said gold reflecting mirror surface is coined.
said gold reflecting mirror surface is coined.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US74641891A | 1991-08-16 | 1991-08-16 | |
| US746,418 | 1991-08-16 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2115770A1 CA2115770A1 (en) | 1993-03-04 |
| CA2115770C true CA2115770C (en) | 1996-09-10 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2115770 Expired - Fee Related CA2115770C (en) | 1991-08-16 | 1992-08-11 | Laterally reflecting tip for laser transmitting fiber |
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| Country | Link |
|---|---|
| CA (1) | CA2115770C (en) |
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1992
- 1992-08-11 CA CA 2115770 patent/CA2115770C/en not_active Expired - Fee Related
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| CA2115770A1 (en) | 1993-03-04 |
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