BACKGROUND OF THE INVENTION Cross Reference to Related Application

The present application is a continuation-in-part of co-pending U.S. Patent Application entitled FIBER OPTIC SCOPE WITH ATRAUMATIC TIP, Application Serial No. 08/230,316, filed April 20, 1994, which is incorporated herein by reference.

Field of the Invention

The invention relates to fiber optic scopes typically used in endoscopic surgical procedures for imaging an area being treated.

Description of Related Art

Small fiber optic scopes have been developed for use in minimally invasive surgical procedures, such as arthroscopy which involves surgery on joints, or laparoscopy which involves surgery within the body cavity/lumen. Such prior art scopes have been developed which are quite small, yet provide a clear image of the region being treated. A state of the art scope may have a diameter in the range of 1.5 millimeters or less.

The structures in which these scopes are provided in the prior art typically include a stainless steel tube providing a rigid structural cover over the optics. Inside the tube, an optic for providing illumination, and an optic for communicating the image are enclosed. The steel cover on such prior art scopes is relatively sharp, and can cause injury during insertion, positioning or exploratory procedures. In the prior art, the edges of the steel cover have been chamfered to reduce the sharpness of the cover. However, chamfering the steel cover has not been entirely

successful, particularly when the scope has a very small diameter. Accordingly, it is desirable to provide a scope whose design is not as sharp and is therefore less likely to cause injury when used to probe a treatment area. A further problem associated with the use of endoscopes is providing sufficient illumination to the region to be viewed. Endoscopes typically include a bundle of fibers which are dedicated to communicating light into the region being viewed. However, as the size of the illumination bundle increases, the cross-sectional area of the endoscope also increases. It is generally desirable to minimize the cross-sectional area of the endoscope in order to minimize the amount of trauma caused to a patient by the introduction of an endoscope into a patient. An endoscope is therefore currently needed which maximizes the amount of illumination provided to a region being viewed per cross- sectional area of endoscope.

SUMMARY OF THE INVENTION The present invention provides an endoscope formed of an image optic and an endoscope body surrounding the image optic. The image optic has a proximal end, a distal end and an image face at the distal end, the image optic providing a field of view through the image face. The endoscope body consists essentially of a plurality of fiber optic filaments bonded together substantially along their entire length by a structural material, the plurality of fiber optic filaments forming an illumination optic having an illumination face near the distal end of the image optic that is arranged to provide illumination in the field of view of the image optic. The endoscope body includes one or more lumens. The image optic used in the endoscope may either be permanently fixed within a lumen of the endoscope body or, preferably, is removable from an endoscope body lumen.

The endoscope also includes an illumination coupler coupled to the fiber optic filaments and positioned near the proximal end of the endoscope body for coupling the fiber optic filaments to a light source. In a preferred embodiment, the endoscope also includes a fluid delivery port coupled to the endoscope body lumen near the proximal end of the endoscope body for delivering fluid through a lumen of the endoscope body to the distal end of the endoscope body. The fluid may be delivered through the lumen within which the image optic is placed or may be delivered through a separate lumen in the endoscope body. In embodiments where the image optic is removable from the endoscope body lumen and fluid is delivered through the lumen within which the image optic is placed, the proximal end of the image optic is preferably shaped relative to the proximal end of the endoscope body such that a water-tight seal is formed. It is generally necessary to apply a moderate amount of pressure to cause fluid to flow through the fluid delivery port out the distal end of the scope. The proximal ends of the image optic and the endoscope body therefore should form a sufficiently strong seal to enable fluid to be pushed through the distal end of the scope. Optionally, the image optic and/or the endoscope body includes a sealing mechanism, such as a gasket, for forming the water tight seal.

In a further preferred embodiment, the illumination face of the illumination optic formed by the endoscope body has an inside edge adjacent and substantially flush with the image face on the image optic. The outside edge of the illumination face is spaced away from the inside edge. The illumination face curves between the inside edge and the outside edge so as to provide an atraumatic tip on the scope or a desired pattern of output light.

In another embodiment of the invention, a window is coupled to the endoscope body to cover the endoscope body lumen at the distal end. The illumination face of the illumination optic has an inside edge

adjacent the window and an outside edge spaced away from the inside edge. Further, the illumination face curves between the inside edge and the outside edge so as to provide an atraumatic tip on the device. By forming the endoscope using an endoscope body that consists essentially of a plurality of fiber optic filaments bonded together substantially along their entire length by a structural material, an endoscope is formed which maximizes the amount of illumination provided per cross-sectional area of the illumination portion of the endoscope. This enables smaller endoscopes to be constructed, thereby minimizing the trauma caused to the patient. In addition, the endoscope of the present invention is easy to manufacture and is relatively inexpensive.

Other aspects and advantages of the present invention will be understood with reference to the figures, the detailed description and the claims which follows.

BRIEF DESCRIPTION OF THE FIGURES Fig. 1 is a perspective view of a fiber optic scope with an atraumatic tip according to the present invention. Fig. 2 is a perspective view of a flexible fiber optic scope with an atraumatic tip according to the present invention.

Fig. 3 illustrates construction of a fiber optic scope with an atraumatic tip in an embodiment including an outer sheath.

Fig. 4 illustrates an endoscope body for use with a fiber optic scope, the endoscope body including an outer sheath.

Fig. 5 illustrates an alternative embodiment of a fiber optic scope according to the present invention in which the endoscope body consists essentially of a plurality of illumination fibers bonded together.

Fig. 6 illustrates another alternative embodiment of a fiber optic scope in which the endoscope body consists essentially of a plurality of

illumination fibers bonded together where the image optic is positioned within and removable from a lumen in the endoscope body.

Fig. 7 illustrates an alternative embodiment of the fiber optic scope in which the endoscope body consists essentially of a plurality of illumination fibers bonded together where the endoscope body also includes an optical window.

Fig. 8 provides a schematic illustration of a curved illumination face on the illumination optic according to the present invention.

Fig. 9 provides a schematic illustration of a faceted illumination face on the illumination optic face fiber optic scope according to the present invention.

Fig.10 is a schematic diagram of a structure used in manufacturing the endoscope body according to the present invention.

Fig. 11 illustrates a mechanism for constructing the head of the endoscope body according to the present invention.

Fig. 12 illustrates a final step in the construction of the endoscope body according to the present invention.

Fig. 13 illustrates an embodiment of the present invention in which the proximal end of the fiber optic scope includes a fluid delivery port.

Fig. 14 illustrates an embodiment of the present invention in which the proximal end of the fiber optic scope includes a fluid delivery port and the image optic is removable from the endoscope body.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention is provided with reference to Figs. 1 through 7, in which Figs. 1 and 2 provide perspective views of fiber optic scopes according to the present invention with atraumatic tips.

Fig. 1 illustrates a straight scope 10, such as typically used in arthroscopic procedures. The scope 10 includes an endoscope body 9 having a head member 11 adapted for coupling to an imaging optical train as known in the art. The imaging optical train may comprise an eye piece, a video camera, or other imaging mechanisms known in the art.

Illumination fibers within the endoscope body 9 are directed into a connector 12 to which an illumination source is connected during use. The head 11 is coupled to an elongated cover 13 which extends to the atraumatic tip 14 according to the present invention. The atraumatic tip

14 according to the present invention is characterized by a scope image face 15 and a curved or rounded illumination face 16 configured to provide an atraumatic tip. The image face 15 is at the distal end of the scope 10 and establishes a field of view generally 17. The illumination face 16 surrounds the image face 16 is substantially flush with the image face on an inside edge and curves away from the image face toward an outside edge. For purposes of the present invention, a curve, or curved surface includes circular, spherical, elliptical, hyperbolic, two or more facet surfaces, and combinations thereof. A plurality of faceted faces can be employed to create an atraumatic tip. Because of the curve on the illumination face, fiber optic filaments within the illumination optic formed by the endoscope body are also curved or sanded output ends. This causes diffused illumination generally 18 near the distal end of the probe, improving the illumination within the field of view 17 of the scope. In addition, the rounded edges blunt the tool to prevent injuries to the patient during use of the tool, and are therefore atraumatic.

Fig. 2 illustrates a scope with an atraumatic tip according to the present invention which is flexible. As illustrated in Fig. 2, the scope includes an outer sheath 23 of the scope 20 that is formed of a flexible material which allows flexing of the scope. Otherwise, the scope

assembly is similar with a head member 21 , and atraumatic tip generally 24.

Figs. 3 through 7 illustrate alternative embodiments of the assembly according to the present invention. In Fig. 3, one embodiment of the distal end of a fiber optic scope is provided. In this embodiment, the scope includes an image optic generally 50 covered with a protective sheath 51. Surrounding the sheath 51 is a tubular endoscope body 52 which surrounds the image optic and extends to the distal end 53 of the tool. Outside the tubular endoscope body 52 is an outer sheath 54 which can be made of a variety of materials including a stainless steel tube, a plastic tube, shrink tube, a coating layer, which imparts a desired rigidity or flexibility to the structure.

The image optic may form an integral part of the fiber optic scope. Alternatively, the image optic may be made removable from the tubular endoscope body.

The image optic 50 has an image face 55 at the distal end 53 of the scope. As discussed above, with reference to Fig. 1 , the image face 55 establishes a field of view for the scope. The tubular endoscope body 52 includes a plurality of illumination fibers to form an illumination optic which includes an illumination face 56 which surrounds the image face 55 and is substantially flush with the image face at inside edge 57. The tubular endoscope body 52 has an outside edge 58 which is spaced away from the inside edge 57. Also, the illumination face has a curve extending away from the inside edge toward the outside edge, thus providing an atraumatic tip on the device.

The outer sheath 54 is preferably made of stainless steel or some other relatively rigid structural material. The outer sheath 54 terminates at point 59 spaced away from the distal end 53 of the scope by a small amount. A filler material 60 is placed at the termination point 59 of the

outer sheath 54, and bonded to the endoscope body 52 so as to smooth over the edge at point 59 of the outer sheath 54.

As illustrated in Figures 3-7, the illumination optic formed by the tubular endoscope body may have a curved illumination face, which provides for diffused illumination in the field of view of the image optic

50.

This tool may be constructed for instance by providing a steel tubular outer sheath 54, and inserting illumination fibers within the tube with a mandrel to establish a space for the image optic. The mandrel can be straight or flared in order to permit the illumination fiber to be flared around a head of the device. This provides maximum space for desired image optics and prevents wasted space. An epoxy or other structural plastic is injected into the tube to form a composite material bonding the illumination fibers inside the tubular sheath 54. The fibers must extend out the tip of the tubular sheath 54 by a small amount, on the order of the diameter of the tubular sheath 54. An epoxy, or other filler material, is then bonded at the edge 59 of the tubular sheath 54 and to the illumination bundle extending out of the tube. The mandrel creating the space for the image optic is removed, and the tip is ground into a desired shape, such as curved or planar, so as to provide an atraumatic tip or a desired pattern of output light. Next, the image optic is inserted, and glued or otherwise bonded to the illumination bundle such that the image face 55 is substantially flush with the inside edge 57 of the endoscope body. In another method of manufacture, a plurality of optical fibers are inserted into a hollow retaining sheath. A removable mandrel is inserted into the bundle of fibers. A mandrel is defined to include anything that blocks off space including, a hollow tube, malleable wire, solid core and the like. An end of the bundle is encapsulated with an epoxy, or other filler material, and then the fibers become bonded together, and form a

composite tip structure. The optical fibers are now in fixed positions with others, such as all extending longitudinally, wound, helical, braided, or the like. A desired shape of the composite tip structure is created by grinding or polishing the tip. It can be circular, planar, beveled with a circular or planar geometry, or any desired configuration which creates a desired pattern of output light. The mandrel is removed before or after the tip is shaped. Additionally, the sheath can also be removed. When the mandrel is removed, a hollow volume, such as an image optic volume, is created. When no sheath is employed, there is no wasted volume so that only illumination fibers and the hollow volume exist. The hollow volume can be used to introduce any variety of devices, such as those used to perform percutaneous procedures.

Suitable sheath materials include but are not limited to flouropolymers, Teflon, PTFE, stainless steel, titanium, plated titanium, metals or plastics, or epoxies. The mandrel can be made of a hard material such as stainless steel, coated with a lubricous material including but not limited to Teflon, a Teflon tube, a Teflon solid core or any lubricous polymer that has a retained shape.

Fig. 4 illustrates an alternative approach to providing an atraumatic tip scope according to the present invention. In this embodiment, a disposable tubular endoscope body 65 is provided. It is constructed substantially in the same way as the scope of Fig. 3, except that the image optic is not inserted. Thus, components having the same structure are given like reference number. Instead of bonding of the image optic 50 into the assembly as described above with reference to

Fig. 3, a window 64 is mounted at the distal end 53 of the structure to seal the interior lumen 67. The window has an image face 66 substantially the same as the image face 55 of the image optic described above with respect to Fig. 3. Thus, an atraumatic sheath which includes the tubular illumination member is provided for use with

a removable scope. This embodiment, the image optic is comprised of a fiber optic scope with a lubricous outside surface, such as Teflon or other low friction material.

Fig. 5 illustrates another alternative embodiment of a fiber optic scope according to the present invention with an integral image optic.

Thus, the scope 70 includes image optic 71 , covered by a protective sheath 72. A tubular illumination member 73 surrounds the image optic 71 and extends substantially to the distal end 74 of the scope. In this embodiment, the sheath 54 is removed, and the illumination bundle 73 is used to provide structural support.

In this embodiment, the endoscope body consists essentially of a plurality of fiber optic filaments bonded together substantially along their entire length by a structural material, the plurality of fiber optic filaments forming an illumination optic having an illumination face near the distal end of the image optic that is arranged to provide illumination in the field of view of the image optic. By forming the endoscope using an endoscope body that consists essentially of a plurality of fiber optic filaments bonded together substantially along their entire length by a structural material, an endoscope is provided which maximizes the amount of illumination provided per cross-sectional area of the illumination portion of the endoscope. This enables smaller endoscopes to be constructed, thereby minimizing the trauma caused to the patient. The fiber optic filaments used to form the endoscope body may consist of glass or silica fiber optic filaments from 20 to 250 microns in diameter. These fiber optic filaments may be bonded into a composite using a medical grade epoxy such as "potting" material/adhesive or an EPO-TEK 300 Series made by EPO-TEK of Massachusetts. The epoxy/fiber optic filament composite may be manufactured using injection molding techniques as known in the art or equivalent molding techniques.

In the embodiment shown in Fig. 5, the tubular illumination member 73 has an inside edge 78 substantially flush with the image face 75 of the image optic 71. The outside edge 76 of the tubular endoscope body 73 is spaced away from the inside edge and the illumination face generally 77 is curved away from the image face 75 so as to establish an atraumatic tip.

Fig. 6 illustrates another alternative embodiment of a fiber optic scope according to the present invention in which the image optic 71 is positioned within and removable from a lumen 81 defined by the tubular endoscope body 73. In this embodiment, the tubular endoscope body consists essentially of a plurality of fiber optic filaments bonded together substantially along their entire length by a structural material, the plurality of fiber optic filaments forming an illumination optic. Accordingly, the tubular endoscope body corresponds to the fiber optic cannula described in co-pending Application Serial No. 08/230,318 entitled FIBER OPTIC CANNULA, filed April 20, 1994, which is incorporated herein by reference. When the image optic is inserted into the endoscope body lumen 79, the tubular endoscope body 73 surrounds the image optic 71 and extends substantially to the distal end 74 of the scope.

According to this embodiment, the fiber optic filaments may consist of glass or silica fiber optic filaments from 20 to 250 microns in diameter. These fiber optic filaments may be bonded into a composite using a medical grade epoxy such as "potting" material/adhesive or an EPO-TEK 300 Series made by EPO-TEK of Massachusetts. The epoxy/fiber optic filament composite may be manufactured using injection molding techniques as known in the art or equivalent molding techniques.

In the embodiment shown in Fig. 6, the tubular endoscope body 73 has an inside edge 78 substantially flush with the image face 75 of

the image optic 71. The outside edge 76 of the tubular endoscope body 73 is spaced away from the inside edge and the illumination face generally 77 is curved away from the image face 75 so as to establish an atraumatic tip. Fig. 7 illustrates the illumination sheath embodiment having a structure similar to that of Fig. 6. Thus, a sheath is formed using the tubular endoscope body 73 in the form of a rigid cannula consisting essentially of a composite of fiber optic filaments and epoxy. The tubular endoscope body includes a lumen 81 adapted to receive an imaging optic as described above with respect to Fig. 6. A window 80 is bounded to the distal end 74 of the tubular endoscope body to establish an image face. The inside edge 78 of the illumination optic formed by the endoscope body 73 is substantially flush with the image face on the window 80. The outside edge of the illumination optic is spaced away from the inside edge, and a curve 77 lies between the inside edge 78 and the outside edge 76 so as to establish an atraumatic tip.

Fig. 8 provides a schematic illustration of the curved illumination face on the illumination optic of a scope according to the present invention. Thus, Fig. 8 illustrates the distal end, generally 100, of an atraumatic scope tip according to the present invention. The scope tip includes an image face 101 on the image optic 102 which is substantially flat, establishing a field of view made at distal end 100 of the scope. Protective cover 103 separates the image optic 102 from the illumination optic formed by the endoscope body. The endoscope body consists of a plurality of fiber optic filaments, such as filament 104 and filament 105. The face of the tubular endoscope body extends from an inside edge, generally 106, that is substantially flushed with the image face 101 , and an outside edge 107, which is spaced away from inside edge 106. The face is curved between the inside edge 106 and the outside edge 107, such as shown in Figure 7.

As illustrated in Fig. 8, the tubular endoscope body 103 has a stainless steel cover 108 which has a distal edge 109. A filler member 110 is coupled to the distal edge 109 and the tubular endoscope body 103 which moves over the distal edge 109 of the cover 108. Filler member consists of an epoxy or other material which may be bonded to the tubular endoscope body 103, or integrally formed therewith by a molding process which forms a tip consisting of a composite of fiber optic filaments (e.g. 104, 105) and a structural material, such as epoxy. Fig. 8 also illustrates the termination of the fiber optic filaments 104, 105 within the tubular endoscope body 103 in the curved surface.

At least a portion of the fiber optic filaments within the tubular endoscope body of the preferred system had a face in the curved portion of the illumination face. For instance, fiber 105 has a face, generally 111, which is angled relative to the face 101 of the image optic. This causes the light emanating from the fiber 105 to diffuse at an angle as shown. In contrast, fiber 104 has a face, generally 112, which is substantially parallel to the face 101 of the image optic. Light emanating from fiber 104 is thus directed substantially straight out of the optic 103. By diffusing the light exiting the illumination member formed by the tubular endoscope body 103, the illumination quality within the region being treated is improved by a more even distribution of light. Further diffusion can be achieved by grinding the illumination member with a fine grit relative to the size of the faces 112, 111 of the fibers 104, 105, so that the faces that are scratched or coarsed. Scratched or coarsened faces on the fibers cause further diffusion of the light emanating therefrom.

Figure 9 shows a multi faceted distal end 100 with an image face 100 on image optic 102. The ends of illumination member formed by the tubular endoscope body 103, consisting of a plurality of fiber optic elements, and shaped so that their output beams are directed to a low

angle field of view. The radius of curvature, or the size and number of faceted faces, or the curved geometry, directs the output beams toward an optical axis of the illumination member. This preserves the amount of available light and little is wasted. Figures 10-12 illustrate one technique for constructing the fiber optic scope of the present invention. Figure 10 represents any one of the tubular endoscope bodies used to form the fiber optic scopes described with regard to Figures 3-7. As illustrated in Figure 10, the filaments 120 are allowed to extend out of the proximal end 122 of the tubular endoscope body 124 so that they may be gathered in following steps into a laterally directed bundle 126 for connection to a source of illumination.

The head 128 of the scope may be manufactured as illustrated in Figure 11. This process involves slipping a lower head member 130 over the tubular endoscope body 132 in an upward direction to capture the filaments 120. An insert 134 is placed over the filaments 120 such that the filaments 120 lay between the insert 134 and the inside wall 136 of the lower member 130. The illumination fibers 120 are then gathered into the channel 137 in the lower member 130 and a top member 138 is lowered over the structure. The filaments 120 can be wound, braided, straight, helical, multi-helical, or combinations thereof. The region between the insert 134 and the lower member 130 may be filled with a glue or epoxy resin to stabilize the structure. Also, the head may be molded or otherwise formed. As can be seen, the filaments 120 are laterally directed into a bundle 126. Thus, as illustrated in Figure 12, the fiber optic filaments 120 have been gathered into the bundle 126 in the walls of a funnel shaped head 142 in the finished structure. This process leaves a lumen 144 through the tubular endoscope body which extends into the funnel shaped head 142. An image optic may then be integrally

incorporated into the illumination lumen 144. Alternatively, an image optic may be employed that is positionable within and removable from the illumination lumen 144.

Figures 13 and 14 illustrate a further, preferred embodiment of the present invention in which the proximal end 148 of the fiber optic scope includes a fluid delivery port 150. Figure 13 illustrates the inclusion of a fluid delivery port on a scope in which the image optic 156 is not removable. Figure 14 illustrates the inclusion of a fluid delivery port on a scope in which the image optic 156 is removable 155. In both cases, the fluid is delivered through the same lumen within which the image optic is placed. It should be understood that the endoscope body may optionally include additional lumens such that fluid is delivered through a lumen other than the lumen within which the image optic is placed. As illustrated in Figures 13 and 14, the fluid delivery port 150 is coupled to the tubular endoscope body 132 near the proximal end 148 of the tubular endoscope body 132 such that fluid 157 may be delivered through the lumen 144 of the tubular endoscope body 132 and out the distal end 154 of the tubular endoscope body 132. As illustrated in Figure 14, when the image optic 156 is removable, the proximal end 158 of the image optic 156 is shaped relative to the proximal end 148 of the tubular endoscope body 132 such that a water-tight seal is formed. Since it is generally necessary to apply a moderate amount of pressure to cause fluid to flow through the fluid delivery port out the distal end of the scope, the proximal ends of the image optic and the endoscope body should form a sufficiently strong seal to enable fluid to be pushed through the distal end of the scope. Optionally, the image optic and/or the endoscope body includes a sealing mechanism, such as a gasket 154, for forming a water tight seal.

Accordingly, the present invention provides a fiber optic scope with an atraumatic tip, which not only avoids injury to patients under treatment, but enhances the illumination quality provided in the region being treated. Alternatively, a fiber optic scope with a low angle field of view, directs the output beams toward an optical axis of the illumination optics, to preserve the amount of available light with little waste.

The fiber optic scope of the present invention also employs a tubular endoscope body formed essentially of a structural material extending from the proximal end of the endoscope body to the distal end of the endoscope body and a multiplicity of fiber optic filaments embedded within the structural material in order to minimize the cross- sectional area of the endoscope in order to minimize the amount of trauma caused to a patient by the introduction of an endoscope into a patient. Further, by eliminating support structures, such as outer sheath materials, the illumination optic formed by the endoscope body is able to house the maximum number of illumination fibers per cross-sectional area, thereby maximizing the illumination provided by the endoscope body per cross-sectional area of the endoscope body.

A combination of these advantages is particularly important in surgical procedures working in small areas where light is important and where small injuries can cause significant harm to the patient. Furthermore, the device is relatively inexpensive and simple to manufacture.

The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling

others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.