ENDOSCOPE WITH INSERTABLE TOOL
FIELD OF THE INVENTION The present invention relates to medical diagnostic and treatment devices. More particularly, the present invention relates to hand held endoscopes used to examine and treat an internal area of a patient.
BACKGROUND OF THE INVENTION Historically, diagnosis and treatment of an internal organ or a bone joint of a patient often required the performance of significantly invasive surgery on the patient. More recently, techniques and equipment have been developed which allow the internal examination of these areas through the use of endoscopy, a much less invasive procedure. The endoscope includes a slender probe which contains an imaging device. The imaging device is connected through the probe to an eyepiece or a video display screen. Endoscopy involves the insertion of the probe into the joint or other area to be examined, followed by examination of the area either through an eyepiece or on a video display screen. It is also now possible to perform relatively non- invasive surgery by insertion of a slender cutting tool through a separate incision into the area to be treated, followed by performance of the necessary surgery with the cutting tool. The surgery is viewed in progress by the physician through an endoscope as described above for the examination procedure. Viewing can be either through an eyepiece or on a video display screen.
This procedure requires two entry points into the area to be treated, one for the endoscope, and one for the cutting tool. Even though the entry incisions are relatively small, they result in some residual soreness of the area, and they constitute some risk of infection, either from the instrument or from post-operative contamination. Additionally, the insertion of multiple instrument's into a joint or other area, and the subsequent manipulation of those instruments will result in some internal trauma to the patient, which is unavoidable.
Further, the insertion and manipulation of multiple instruments can be awkward for the physician, and it may be difficult to maneuver the endoscope to effectively view the operations being performed by the cutting tool. This awkwardness is especially detrimental if the surgery tool being used has a cutting contour that is always exposed, subjecting the surrounding tissue to possible inadvertent lacerations. In addition, after inserting a cutting tool into the surgery area, the physician often needs to remove the cutting tool and use an entirely different tool with a different configuration. Such tools can include, for example, a scalpel, a chisel, a probe, a hook, or a biopsy needle, as well as many others. Finally, endoscopes and cutting tools that are not designed to be disposable must be sterilized before use, so the use of multiple instruments means an increased burden of sterilization.
Accordingly, it is an object of the present invention to provide an endoscope which is capable of performing a variety of surgical operations with an interchangeable insertable tool, as well as providing a means of examination of the area during surgery. It is a further object of the present invention to provide an endoscope which contains means for illuminating a treatment area, means for the viewing the area, and means for performing the surgical treatment, all on one instrument. It is a still further object of the present invention to provide an endoscope which is relatively inexpensive to manufacture and comparatively easy and cost-effective to use.
SUMMARY OF THE INVENTION
In a preferred embodiment which is only exemplary of the present invention, a portable endoscope assembly has a hand held housing assembly, with an elongated probe attached to the housing assembly. The probe includes a tubular steel cannula which is mounted on the housing assembly. A handle portion of the housing assembly extends at an angle from the axis of the probe. The probe has a plurality of passages therethrough, leading to a plurality of openings in its distal end, to facilitate illumination, viewing, irrigation, aspiration, and treatment of the affected area. A video camera assembly is attached to the handle assembly, at an angle to the axis of the probe. A surgical implement can be inserted through a sealed opening in the proximal end of the housing assembly and on through one of the passages in the probe, so as to be extended through one of the openings in the distal end of the probe. The surgical implement can also be retracted within the opening at the distal end of the probe. In accordance with the preferred embodiment of the present invention, a cylindrically-shaped GRIN rod is mounted near the end of the probe. Light which is reflected by the interior structure of the joint enters the distal base of the cylindrically-shaped GRIN rod and is focussed by the GRIN rod onto the GRIN rod's proximal base.
To transfer the image back through the probe, the proximal base of the GRIN rod is attached to the distal end of a fiber optic image guide. This image guide extends through the probe. If it is desired to view at an off-axis angle, rather than along the axis of the probe, the image guide can be bent near its distal portion to form an angle of about twenty-five (25) degrees between the distal portion of the image guide and the axis of the probe. In a probe designed for off-axis viewing, therefore, the axis of the GRIN rod is not parallel to the axis of the probe. Accordingly, when the scope assembly is turned to rotate the image guide about its axis, the distal base of the GRIN rod is moved through a donut-shaped swath which enables the GRIN rod to scan a relatively large area of the internal structure of the joint. The arrangement of these components for off-axis viewing is fully disclosed in U.S. Pat. No. 5,188,093, which is incorporated herein for reference.
Whether the probe is designed for on-axis or off-axis viewing, the image guide is optically joined to focussing optics which are mounted in the camera assembly. The focussing optics are optically joined with a camera head which is mounted in the camera assembly and which is electrically connected to a camera control unit external to the endoscope. The camera control unit can control a CRT or other visual display device to display the image of the internal structure of the joint.
Also, to illuminate the interior structure of the joint, a plurality of optical illumination fibers are mounted within the probe next to the image guide. These illumination fibers extend through the scope assembly and are joined with an optical cable that is mounted inside the camera assembly. The other end of the optical cable can be irradiated with light from a quartz halogen lamp or other suitable light source which can be located either in the scope assembly, in the camera assembly, or externally to the camera assembly. Thus, light from the lamp can be transmitted through the optical cable and illumination fibers to illuminate the internal structure of the joint. Fluid for irrigation of the treatment area can also be supplied through another one of the passages in the probe, and fluid can be aspirated from the treatment area through still another one of the passages.
A surgical implement, which can have a variety of operative elements on its distal end, as desired, is inserted through the housing assembly, extending through yet another passage in the probe. The contours of the operative element on the implement can be straight, curved, pointed or blunt, as required for the surgery to be performed. The surgical implement can be withdrawn and replaced with another implement having another operative element on its distal end, with relative ease. The operative element of the surgical implement can be selectively extended from the opening at the distal end of the implement passageway, or retracted into the opening, as desired. Therefore, illuminating light is shed by a light source, received by the proximal end of the illuminating optical fibers, and transmitted by those optical fibers to the open distal end of the probe. At the distal end of the probe, which has been inserted into the patient, at the treatment area, the illuminating light exits the probe. Portions of this light are reflected by the internal structure of the treatment area, and the reflected light is received by the distal end of the GRIN rod. The GRIN rod focusses the reflected light onto its proximal end as the image of the internal structure of the treatment area.
This image is then transmitted by the optical fiber image.guide to focussing optics where the image is focussed for viewing either through an eyepiece or on a video display tube. While viewing the image of the internal structure of the treatment area, the physician can examine the area, determine the proper treatment, and insert the appropriate surgical implement through the scope assembly to perform any required surgery. The surgical implement can also be partially withdrawn as desired, to facilitate further manipulation of the instrument without causing unwanted trauma to surrounding tissue. If necessary, the surgical implement can be completely withdrawn from the scope assembly and replaced with another implement. If required during diagnosis or treatment, irrigation fluid can be introduced into the treatment area through the probe, and fluid or other material can be aspirated from the treatment area through the probe.
The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of the endoscope of the present invention in its intended environment;
Fig. 2 is a perspective view of a preferred embodiment of the endoscope of the present invention, showing the major components;
Fig. 3 is a section view of the endoscope shown in Fig. 2;
Fig. 4 is a perspective view of the distal end of the probe of the endoscope shown in Fig. 2, with the surgical implement extended;
Figs. 5 through 7 are perspective views of the distal end of the probe of the endoscope shown in Fig. 2, showing examples of different types of surgical implements which can be used.
DESCRIPTION OF PREFERRED EMBODIMENTS As seen in Fig. 1, the endoscope 10 includes a probe 12, which is attached to housing assembly 14 to which is also attached a handle 16. The physician inserts the probe 12 into an incision 20 in the knee 18 of a patient. The endoscope 10 can be used to examine and treat various body parts, and it can have various configurations of these basic components according to the application. It is shown here for treatment of a knee, simply by way of example. Instead of being inserted directly into an incision 20, as is known in the art, it is also known in the art that it can be inserted through a cannula (not shown) which has been inserted into the incision 20.
Figure 1 also shows that camera assembly 60 on endoscope 10 is electrically connected via cable 62 to a camera control unit 66. Camera control unit 66 can in turn be electrically connected to a video display 64, as shown in Figure 1, for displaying a video image of the internal structure of knee 18. Cable 62 can also include an optical fiber from a light source located external to camera 60, possibly incorporated in a housing with camera control unit 66. Irrigation fluid can be provided to endoscope 10 through irrigation tubing 68 from fluid source 72, such as a pump. Fluid and other material can be aspirated via endoscope 10 through aspiration tubing 70 by vacuum source 74. As seen in Fig. 2, on a larger scale, endoscope 10 has an elongated, slender, hollow tubular probe 12, which has a distal end 22 and a proximal end 24. Proximal end 24 of probe 12 is fixedly attached to distal end 26 of housing assembly 14. Handle 16 is attached at an angle to housing assembly 14 , or handle 16 can be an integral part of housing assembly 14. Camera assembly 60 is attached to handle 16 by means of collar 17. Housing assembly 14 and handle 16 serve to transfer illumination light from camera assembly 60 to components in probe 12, and to transfer an optical image of the treatment area from probe 12 to camera assembly 60 for display. Proximal end 15 of housing assembly 14 also serves as an access point for insertable surgical implement 50, which passes through housing assembly 14 and extends from distal end 22 of probe 12, as will be described later. During use, the physician handles the instrument by handle 16, distal end 22 of probe 12 is inserted into the treatment area of the patient, and the image of the treatment area can be observed through an eyepiece or a video display connected to handle 16. If surgery is required, the appropriate surgical implement 50 can be inserted and moved forward to extend operative element 52 of surgical implement 50 from the distal end 22 of probe 12.
Fig. 3 shows a section view of endoscope 10. Probe 12 is a tubular needle which has a plurality of longitudinal internal passageways, and which has corresponding openings at its distal end 22. Illumination optical fibers 30 pass through housing assembly 14, including handle 16, and run the full length of probe 12, generally parallel to the longitudinal axis of probe 12. The number, size, and arrangement of illumination fibers 30 can vary from one to any number, as long as they transmit sufficient light to their distal ends to illuminate the area to be examined and treated. Illumination fibers 30 can be arranged in a number of different ways within probe 12. Figure 4 shows one such arrangement. The method of permanently mounting illumination fibers 30 inside probe 12 is known in the art and does not constitute part of the present invention. Similarly, illumination fibers 30 are connected as is known in the art to a light source via handle 16. Also shown in Fig. 4 is the distal end of GRIN rod 32, which is permanently installed in probe 12. Again, GRIN rod 32, or some other light gathering lens structure could be in a variety of sizes, shapes and configurations without departing from the present invention, as long as it gathers sufficient light and focusses the image sharply enough to provide a clear image for viewing by the physician. As is known in the art, the proximal end of GRIN rod 32 is attached to the distal end of an image guide in the form of an optical fiber 37, which then extends the full length of probe 12. Optical fiber 37 passes through housing assembly 14, as shown in Figure 3, and is exposed at its proximal end for the transmission of an image to the video camera assembly 60.
Again in Fig. 4, exposed at distal end 22 of probe 12 are fluid passageways 46 and 47, which run the length of probe 12. Passageway 46 can be provided for the introduction of irrigation fluid into the treatment area to remove blood or tissue from the area being viewed. Passageway 47 can be provided for the aspiration of tissue or fluid from the treatment area. These passageways in probe 12 can be connected to irrigation duct 48 and aspiration duct 49, respectively, for the transport of fluid through housing assembly 14, by means that are well known in the art.
According to the present invention, also shown in Figure 4 is a surgical implement 50 mounted in implement passageway 45 so as to have its operative element 52 extendable beyond, or retractable within, the distal end 22 of probe 12. Operative element 52 is shown as a cutting contour on implement 50, but it could also be a chisel, a solid probe, a biopsy needle, or some other element. Surgical implement 50 extends generally parallel with the longitudinal axis of probe 12. The particular surgical implement 50 shown in Fig. 4 is a relatively flat blade with a blunt tip 40 on its distal end. It also has a blunt edge 36 on one side and a sharp cutting edge 38 on the opposite side oriented substantially radially within probe 12.
Surgical implement 50 can be extended from passageway 45 a sufficient distance to expose cutting edge 38, or it can be retracted within passageway 45 to completely enclose cutting edge 38. Implement 50 is shown oriented radially, but it could be oriented in some other fashion, depending upon the type of surgical implement being used. The extended position of surgical implement 50, shown in Fig. 4, is used for implementation of the tool, and the retracted position (not shown) , is used whenever the tool is not in use.
Figure 3 shows one way in which surgical implement 50 can be extended and retracted. In summary, implement 50 should be capable of extension to completely expose its useful contours, it should be capable of complete retraction to prevent its contours from contacting any surrounding tissue, and it should remain in the desired position. Housing assembly 14 has within its proximal end 15 a seal block 19 formed of a slightly deformable but dimensionally stable plastic material, such as an acetal homopoly er. Shaft 55 of implement 50 fits tightly in the central bore through seal block 19. The proximal end of seal block 19 can have a tapered entrance port to assist in aligning implement 50 upon insertion of implement 50 into the central bore through seal block 19. A cavity can be formed within seal block 19 to hold elastomeric o-ring 21, which seals against shaft 55 of implement 50.
O-ring grooves 56, 58 are formed around the surface of shaft 55, to selectively align with o-ring 21. Grooves 56, 58 are axially spaced along shaft 55 at the appropriate locations to hold implement 50 in the desired extended or
• retracted position, respectively, by alignment with o-ring
21. Extension and retraction of implement 50 is accomplished by pushing or pulling on implement handle 54, attached to the proximal end of shaft 55.
As seen in Figs. 5 through 7, the endoscope of the present invention can incorporate a variety of surgical implements, examples of which are shown and designated 50'.
OPERATION The endoscope 10 of the present invention is inserted into incision 20 in the knee 18 of the patient, either directly or through a separate cannula. During insertion of the probe 12, surgical implement 50 is preferably retracted within probe 12. When the distal end 22 of the probe 12 is in the proximity of the area to be examined and treated, the physician can view the area to examine the pertinent tissue and formulate a treatment. If surgery is indicated, the physician can push forwardly on implement handle 54 until o-ring 21 seats in proximal groove 56, to extend operative element 52 on the distal end of implement
50 from probe 12. Then, scope handle 16 and implement handle 54 can be manipulated to simultaneously maneuver the field of view and surgical implement 50 to cut, probe, or move tissue as required. Since surgical implement 50 will always be positioned in or near the illuminated field of view, the physician can view the surgery in progress with a minimum of awkwardness, and without having to simultaneously maneuver a multiplicity of instruments.
If a different surgical implement is required, the installed implement can be completely withdrawn from the endoscope by pulling on handle 54, and replaced with the desired instrument. When surgery is complete, or when maneuvering of the field of view is desired, surgical implement 50 can be retracted within probe 12 by pulling on handle 54 until o-ring 21 seats in distal groove 58.
While the particular endoscope with an insertable implement as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.