Abstract:
An endoscope for eye surgery incorporates a handle having a camera and an electric motor driven lens assembly for enabling a user to focus the camera during surgery without manually adjusting the focus. The endoscope includes a probe attached by a rotatable bayonet type connector with a simple pivoting lever to release the probe from the handle. The motor drive system incorporates spring biasing to compensate for overruns of a drive nut on a lead screw when the user attempts to exceed the focal range of the lens assembly.

Description:
This application claims the benefit of U.S. Patent Application Serial No. 60/266,354, filed on Feb. 2, 2001 which is specifically incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to an endoscopic system and method of use and, more particularly, an endoscopic system and method useful in eye surgery for illuminating, viewing, lasing and washing an area of an eye of a patient to be operated upon. 
     DESCRIPTION OF THE BACKGROUND ART 
     The use of endoscopes and other surgical devices of known designs and configurations is known in the prior art. 
     By way of example, the prior art includes U.S. Pat. No. 5,093,719 to Prescott entitled Endoscopic Gradient Index Optical Systems. This patent discloses gradient index endoscopic or borescopic systems in forms ranging from basic to more complex depending on the optical task. The basic form comprises a gradient index objective of less than a quarter period in length followed by a gradient index relay whose length is at least one-quarter period longer than the distance of the first image of the object into the relay. The numerical aperture of the objective is preferably larger than that of the relay to provide a wide angle endoscope with an entrance aperture tunnel preceding the objective. In one embodiment with a line-of-view prism, the entrance tunnel is placed in the most restricted aperture within the prism thus minimizing or eliminating vignetting of the field of view. A second embodiment of this subsystem is an endomicroscope wherein the entrance pupil moves and changes size as the ocular focus of the system is changed. The endoscope retains the maximum possible Lagrangian of the system as limited by the numerical aperture and diameter of the relay for all foci. The prior art also includes U.S. Pat. No. 5,095,887 to Leon entitled Microscope-Endoscope Assembly Especially Usable in Surgery. This patent relates to an optical assembly comprising a microscope including a binocular with a pair of oculars, an optical body and an objective lens and an optical path; and an endoscope provided with an extension, an outlet ocular, and an optical path. A commutating modulus is disposed between the binocular and the optical body of the microscope and the outlet ocular of the endoscope so as to enable an observer whose eyes are located at each ocular of the microscope to observe selectively either (a) the optical path of the microscope or (b) the optical, or electronic, path of the endoscope or (c) both optical paths simultaneously to scan an object to be investigated. 
     In this respect, the endoscope system of the present invention departs substantially from the conventional concepts and designs of the prior art, and in so doing provides a method and apparatus with selectively uncouplable and couplable components primarily developed for the purpose of illuminating and/or viewing and/or lasing and/or washing an area of a patient, such as en eye, to be operated upon. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a new and improved endoscope system and method of use for illuminating, viewing, lasing, and washing an eye area of a patient being operated upon comprising, in combination a distally positioned needle component in a generally cylindrical configuration. The needle portion has a distal face and a centrally located tubular needle with a major bore extending distally therefrom and a generally planar proximal face. The major bore has four minor bores axially aligned within the major bore. The proximal face has a plurality of proximally extending tubes including an enlarged viewing tube with an observation bore axially aligned with the major bore of the needle and with two supplemental tubes extending proximally from the proximal face. Each supplemental tube has a bore and an additional tube extending laterally from the needle component. The additional tube is couplable proximal to a source of washing fluid. The first minor bore is in axial alignment with the observation bore with a first lens within the first minor bore and observation bore with the first lens adapted to transmit optical images from the distal end of the needle to the proximal end of the observation tube. The second minor bore and a supplemental tube are coupled through a first angled transistion bore and contain first optical strands for effecting illumination at the distal end of the needle. The third minor bore and the other supplemental tube are coupled through a second angled transistion bore and contain a second optical strand for lasing or fluid infusing. A proximally positioned handle component has a proximal end and an essentially flat distal end with a plurality of axially aligned bores therethrough. It includes a central bore in axial alignment with the observation bore of the needle portion for the receipt of the main tube terminating at the proximal end with internal threaded recess for the removable receipt of a viewing instrument. A second lens is located within the central bore in optical communication with the first lens of the needle component and illumination fibers within one of the supplemental bores in optical alignment with the illumination fibers of the needle component. A lasing fiber or infusion tube is located in the other of the supplemental bores in optical alignment with the lasing fiber of the needle component. The bores at the distal end of the handle component are sized for the receipt of the observation tube and supplemental tubes of the needle component. A bayonet type connector enables rapid separation of the needle component to the handle component. A pivotable locking level prevents separation of the components during use. The handle includes an electric motor-driven focusing assembly to enable the user to rapidly change focus while using the device. Also included is the method of using an endoscope system which includes the step of providing the components as described above including the further step of uncoupling and coupling the needle and handle components as may be required for a particular application. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     It is therefore an object of the present invention to provide a new and improved endoscope system and method which has all the advantages of the prior art surgical devices of known designs and configurations but with added capabilities. 
     It is another object of the present invention to selectively uncouple and couple components of an endoscope system to meet the requirements of a particular application. 
     It is a further object of the present invention to provide a new and improved endoscope system which is of a durable and reliable construction. 
     Still yet another object of the present invention is to tailor miniaturized surgical systems for illuminating and/or viewing and/or lasing and/or cleaning as needed for a required observation or treatment. 
     Still another object of the present invention is to illuminate, view, lase and wash an area of a patient to be operated upon. 
     These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated the preferred embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: 
     FIG. 1 is an exploded perspective illustration of the preferred embodiment of the endoscope system constructed in accordance with the principles of the present invention; 
     FIG. 2 is a cross-sectional view of the device shown in FIG. 1 taken axially along the length thereof along line  2 — 2  with the needle component and handle component being coupled for operation and use; 
     FIGS. 3 and 4 are cross sectional views taken along lines  3 — 3  and  4 — 4  respectively of FIG. 1, FIG. 3 being greatly enlarged; 
     FIGS. 5 and 6 are end elevational views taken along lines  5 — 5  and  6 — 6  respectively of FIG. 1; 
     FIG. 7 is an exploded perspective view similar to FIG. 1 but taken from the opposite side thereof; 
     FIG. 8 is a cross-sectional view of an endoscope in accordance with one embodiment of the present invention; 
     FIG. 9 is an enlarged view of the handle assembly of FIG. 8; 
     FIG. 10 is an enlarged view of the probe end of the endoscope of FIG. 8; and 
     FIGS. 11 a  and  11   b  are end views of the handle of FIG. 9 showing the handle to probe coupling system. 
    
    
     Similar reference characters refer to similar parts throughout the several views of the drawings. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference now to the drawings, and in particular to FIGS. 1 through 7, thereof, an example of one existing form of endoscope system is shown. The endoscope  10  includes a distally positioned needle component  14  as one of its two primary components. See FIGS. 1,  2  and  7 . At least a portion of the needle component is preferably formed in a generally cylindrical configuration. The needle component has a distal face  16  and a centrally located tubular needle  18  extending distally from the center of the distal face. The needle has a major bore  20  extending axially and centrally located within the entire length of the needle. The needle component is formed with a generally planar proximal face  22 . As can best be seen with reference to FIG. 3, the major bore of the needle has four minor bores  24 ,  26 ,  28 ,  30  axially oriented within the major bore for purposes as will be later described. The proximal face  22  of the needle component has a plurality of proximally extending tubes. Such tubes include an enlarged viewing tube  32  with an observation bore  34  axially aligned with, and an extension of, the centrally oriented first minor bore  24  of the needle. The proximally extending tubes also include, in the preferred embodiment, two supplemental tubes  36 ,  38  extending proximally from the proximal face. Each supplemental tube has a bore  40 ,  42 . Further, an additional tube  42  extends laterally and proximally from the needle component. The additional tube is couplable proximally to a source of washing fluid, not shown. 
     The first minor bore  24  of the needle is in axial alignment with the observation bore  34  of the viewing tube. A first lens  48  is located within the first minor bore and the observation bore  34 . The first lens  48  is the first optical component and is adapted to transmit optical images from the distal end of the needle to the proximal end of the viewing tube. 
     As can be best seen in FIG. 2, the second minor bore  26  and the first supplemental tube  36  are optically coupled through a first angled transition bore  50  and contain a second optical element, strands  52  for effecting illumination of the area to be viewed adjacent to the distal end of the needle. The optical strands are located within the major bore of the needle in regions other the locations of the other optical elements. Such regions are considered the second minor bore. The third minor bore  28  and the second supplemental tube  38  are coupled through a second angled transistor bore  54 . Note again FIG.  2 . Such bores and tube contain a third optical element, an optical strand  56 . Such optical strand functions for lasing at the area being viewed. 
     The fourth minor bore  30  is directly coupled to a source of pressurized fluid through the additional tube  44 . Such bore and tube are in operative communication, one with the other, and are normally empty except when a fluid from the pressurized source, not shown, is employed to inject a washing or irrigation fluid against the area of the patient being viewed and/or operated upon. 
     A proximally positioned handle component  58  constitutes the second major component of the endoscope system. Such handle component has an essentially flat distal end  60 . It also has a proximal end  62 . The proximal end includes a plurality of axially parallel bores  64 ,  66 ,  68  therethrough. Such bores include an enlarged central bore  64  in axial alignment with the viewing tube  52  of the needle portion for the receipt of the viewing tube. Bores  66  and  68  at their distal ends are sized and positioned for the receipt of the supplemental tubes  36 ,  38  of the needle component. Compare FIGS. 1,  6  and  7 . The handle component terminates at its proximal end with a centrally located, internal threaded recess  70  for the removable receipt of a viewing instrument, not shown. Additionally, two supplemental tubes  72 ,  74  extend through the handle component from the distal end to and beyond the proximal end. Such tubes terminate proximally with threaded ends  76 ,  78 . 
     A second lens  80  is located within the central bore adjacent to the proximal end of the handle component in optical communication with the first lens  48  located adjacent to the distal end of the needle component. Such lenses function together to transmit images from the distal end of the needle to the proximal end of the handle component and rearwardly thereof to the viewing instrument. In addition, illumination strands  82  are located within the first supplemental tube  72  in operative alignment with the strands  52  of the second minor bore of the needle. A lasing strand  84  is located in the second of the supplemental tube  74  in axial alignment with the lasing strand  56  of the third minor bore of the needle. 
     The threaded ends  76 ,  78  of the supplemental tubes  72 ,  74  are adapted to be coupled to a source of illumination and to a laser source, respectively, when the needle component and handle component are coupled together for operation and use. Neither the source of illumination nor the laser source nor the above-referred to source of pressurized fluid are shown since such are essentially conventional in their constructions. Typical conventional constructions are described and referred to in the aforementioned U.S. Pat. No. 5,03,719 to Prescott. 
     The bores  64 ,  66 ,  68  at the distal end of the handle component are sized for the separable receipt of the viewing tube  52  and supplemental tubes  30 ,  32  of the needle component. This arrangement allows for the use of various needle components having various optical elements with various handle components having corresponding optical elements. For example, one needle component may be used with a variety of handle components. Conversely, one handle component may be used with a variety of needle components. In addition, the separability of the needle and handle components allows for different first and second lenses to be utilized one with another for tailoring a lens system for a particular application. 
     A threaded radial bore  86  is located in the handle component. An associated set screw  88  is threadedly received within the radial bore. The radially end of the set screw is located to be positioned within an annular recess  90  formed in the exterior surface of the viewing tube during operation and use of the system. These features are best seen in FIGS. 2 and 4. This allows for the selective separation of the major components as well as for the secure coupling between the needle component and the handle component as may be needed for a particular application. 
     A collar  92  is also located at the distal end of the handle component. The collar extends distally from the distal end of the handle component, circumferentially around the entire handle component for 360 degrees. The collar functions to receive and properly position the proximal end of the needle component to the distal end of the handle component during operation and use of the system. A collar extending around less than 360 degrees has also been found to function properly. 
     While the endoscope shown in FIGS. 1-7 is a substantial improvement over other endoscopes, it has been found that additional improvements are needed to simplify exchanging probes to handles during operations on patients when the fragile GRIN lens is often broken and also to enable better focusing of the viewing camera during such operations. FIGS. 8-11 illustrate such an improved endoscope. 
     The present invention is an improved form of the endoscope described above. Turning now to FIG. 8, is shown a cross-sectional view of an endoscope incorporating the teachings of the present invention. The endoscope comprises a handle portion  100  and a detachable probe portion  102 . A needle  104  containing the optical and other components described above with regard to FIGS. 1-7 extends from the end of the endoscope. FIG. 9 is an enlarged view of the handle portion  100 . Within the handle portion  100  there is a camera  106  having a front imaging lens  108 . Immediately forward of the camera lens  108  is a spring loaded lens assembly  110  including a lens barrel  112  and lens  114 . The lens assembly  110  is positioned within a fitted cylindrical cavity  116  and is biased towards the forward end of the cavity  116  by spring  118 . At the top of the cavity  116  is a slot  120  for receiving a pin  122  downward into engagement in a circumferential groove  115  in the lens barrel  112 . The slot and pin are so designed that the lens barrel can move longitudinally within the cavity  116  to achieve focusing of the camera on the viewing optics. The pin  122  is fastened to a follower nut  124  which rides on a lead screw  126 . The lead screw  126  is driven by a coupler  128 , which coupler is attached to a small gear motor  130 . An opposite end of the lead screw is supported in a fixed brass bearing member  131 . The end of the coupler  128  attached to the lead screw includes a bore in which a spring  132  is seated. An end of the lead screw  126  extends into the bore and is biased outwardly by the spring  132 . The coupler includes a slot which engages a flange on the lead screw and allows the motor  130  to drive the lead screw through the coupler and cause the follower nut  124  to move longitudinally within the handle  100 . The movement of the follower nut  124  correspondingly moves the lens assembly  110  allowing the user to focus an image appearing at the window end  134  of the handle onto the lens  108  of the camera  106 . 
     One of the advantages of the present design is that the drive mechanism for the lens assembly  110  is capable of being over driven in either direction without becoming inoperative. The threaded portion of the lead screw  126  is less than the length of the follower nut  124  and may be, for example, about ⅛ inch in length. The threaded portion of the nut  124  is also short but selected to be at least as long as is needed to achieve focus for all uses of the endoscope. If the nut  124  is overdriven, the follower nut  124  can actually separate from the threaded portion of the lead screw  126 , such as by the drive motor  130  being energized to rotate in one direction for an extended time. If the nut  124  is driven towards and into engagement with bearing member  131 , lead screw  126  will be driven in an opposite direction such that coupler  128  further depresses spring  132 . Spring  132  maintains a force on lead screw  126  so that the threads of the screw and those of nut  124  are urged towards one another. Consequently, when the motor  130  reverses direction, the threads engage and allow the nut to move on the lead screw. If the lead screw is driven in the reverse direction for an extended time, nut  124  will drive off the opposite end of the threaded portion of the lead screw  126 . In that event, the spring  118  exerts a force through pin  122  via lens assembly  110  to urge nut  124  in an opposite direction so as to engage the threads of the nut and lead screw when the motor drive reverses. 
     In the embodiment of FIG. 8, the primary functions of imaging and lighting from the end of the endoscope are handled through the length of the handle  100  so that there are no protruding tubes or wires to interfere with the use of the endoscope. However, there is one additional probe input that protrudes through the probe end  102 . Referring to FIG. 10, the end of the handle  100  is shown in engagement with the probe  102  with the handle rotated so as to illustrate positioning of one external guide rod  140  for passage of air or fluid for use in eye surgery. One of the advantages of the present invention is that the probe end  102  separates from the handle  100  by merely depressing a locking lever  142 . When the lever  142  is depressed, the probe assembly can be rotated and separated from the handle assembly. The arrangement of the contacts within the probe assembly are such that positive locking is established between the probe assembly and handle. Referring to FIGS. 11 a  and  11   b , there are shown end views of the handle with the mating elements of the probe in an insert position and in a locked position illustrating how the probe rotates using a bayonet type of connection to quickly attach or remove a particular probe and yet assure positive alignment between the probe and handle. The handle  100  has three cantilevered and tilted flanges  150   a ,  150   b  and  150   c  which extend radially inward. Probe portion  102  incorporates three mating flanges  152   a ,  152   b  and  152   c . When probe portion  102  is pressed into engagement with handle  100 , the flanges  152  fit into spaces intermediate flanges  150 . Rotation of probe portion  102  allows flanges  152  to rotate under flanges  150 . Since flanges  150  are tilted or angled circumferentially, such rotation tightens the engagement between probe portion and handle and pulls the two sections together. The locking lever  142  establishes the final engagement position by slipping into a slot  154  in probe portion  102 . A cam surface  156  on probe portion  102  is used to raise the lever  142  as the probe portion is rotated. The slot  154  is located at the end of the cam surface  156 . The locking lever  142  fits into the slot  154  in the probe when the probe is properly positioned with regard to the handle so as to accurately place the probe onto the handle. While the locking lever is illustrated as having a substantially rectangular cross section, it will be appreciated that the end which engages into the probe to assure proper positioning with respect to the handle could in fact be tapered to assure exact placement of the angular orientation of the probe  102  with respect to the handle  100 . 
     The present invention also includes the method of use of an endoscope system. Such method includes the steps of providing the components as described above as well as the steps of illuminating and/or viewing and/or lasing and/or washing with such components and the further step of uncoupling and coupling the needle component and handle component and interchanging such components for a particular application.