Abstract:
An endoscopic instrument having a ball and socket connection for releasably attaching a front end assembly to an actuating handle assembly comprising of a base having a downwardly extending stationary handle and a pivoting handle. The socket comprising a plurality of resilient prongs to create a friction fit that can be disengaged by the surgeon retracting the pivoting thumb handle. The socket disposed in the base and linkage provided for actuating the instrument.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to surgical instruments, and more particularly to an endoscopic instrument having improved means for removably connecting the actuation rod. 
     2. Description of the Prior Art 
     Endoscopic medical procedures for surgery and diagnosis are widely practiced throughout the world today and their acceptance is growing rapidly due to the associated advantages relating to reduced trauma and hospitalization time. These procedures are generally referred to as &#34;minimally invasive surgery&#34;. Various types of endoscopic surgical instruments are known in the art. These instruments generally include a slender tube containing a push rod which is axially movable within the tube by means of a manual actuator. One or more end effector mechanisms are coupled to the distal ends of the tube and the push rod so that axial movement of the push rod is translated to rotational or pivotal movement of the end effector mechanisms. End effectors may take the form of scissors, grippers, cutting jaws, forceps, and the like. 
     Traditionally endoscopic instruments have been manufactured as reusable devices which can be cleaned and sterilized following a procedure, or as disposable devices which are discarded after a single surgical procedure. With disposable devices cleaning is not an issue since they are not reused or resterilized. One of the most common problem is that the end effectors often get dull from use and must be discarded. The end effectors of reusable instruments must always be cleaned and properly sterilized after each surgical procedure. Although techniques such as steam sterilization have been widely used, they are often inadequate to reach all of the blood and tissue residues that can enter an instrument during a surgical procedure. Endoscopic instruments are often constructed with an elongated tubular body housing and small precisioned mechanical parts. Microscopic pockets of blood and tissue, which can infiltrate the body of the endoscopic instrument, are often left on the instrument even after completion of accepted sterilization procedures. Frequently this is because the instrument cannot be adequately disassembled. This creates a concern of infectious disease and the potential of cross-contamination to patients and health care professionals alike. In order to insure complete sterization of a surgical instrument, the instrument must be capable of easy disassembling into its major components. This insures that all surfaces of the instrument are exposed to the particular sterilization medium and any concern that the instrument is not thoroughly sterilized is thereby eliminated. 
     The advantages of disposable, one time use of these instruments is often compromised by the high cost per instrument and the environmental problems associated with medical waste disposal. The benefits of endoscopic instruments, that are easy to use and which can be assembled and disassembled with a minimum of wasted time due to an economy of parts, have long been recognized. Especially important is an endoscopic instrument having end effector mechanisms which can be easily disconnected for discarding, because it is this part that most often becomes worn, dull and requires the greatest degree of cleaning care. 
     An example of a surgical instrument that depicts a removable front end is shown in U.S. Pat. No. 5,718,714 issued to Livneh on Feb. 17, 1998. Livneh teaches of a handle assembly having a releasable coupling member which releasably connects with the front end member. The front end member is capable of rotation and the rotation can also be inhibited by a locking member. This patent discloses the advantages from being able to use a variety working front end elements. The proximal end of the front end shaft is seated within a rigid slot. Entrance to the slot is by manually turning a cap assembly that opens up access to the slot therein. 
     U.S. Pat. No. 5,618,308 issued to Holmes et al., discloses a simple surgical instrument which seats the inner rod within the thumb loop housing by means of a rigid slot. Several steps are required to remove the connecting member from the housing. 
     U.S. Pat. No. 5,618,303 issued to Marlow et al., discloses a knurled knob for easy rotation of the actuator rod. He also teaches the removal of only the working part of the instrument, This is the part of the instrument that is most likely exposed to contamination and also the hardest to clean. The mechanism for connecting the working end to the shaft can often be almost as difficult to clean as the original working member. 
     U.S. Pat. Nos. 5,782,748 and 5,746,759 are presented as examples of the prior art seeking to disclose detachable shaft connections. 
     None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     Accordingly, the above problems and difficulties are obviated by the present invention which provides for an endoscopic instrument having a removable front end that utilizes a ball and socket connection to a handle housing. The socket connection is relatively flexible, being comprised of a plurality of resilient prongs. 
     More particularly, the endoscopic surgical instrument of the present invention is comprised of a handle assembly, an elongated endoscopic front end assembly extending from the handle assembly and an end effector mechanism being supported on a distal end of the front end assembly. The end effectors actuate between open and close positions by movement of a pivoting thumb handle which pivots in relation to a stationary finger handle. The end effectors may comprise a pair of jaw members wherein one or both jaw members open and close to perform various endoscopic surgical procedures. The mechanism includes, but is not limited to, scissor devices, dissecting devices, retractor devices, and like mechanisms. 
     The front end assembly is comprised of a tubular sheath element with a cointensive actuation element coaxially transposed within it, such that it interconnects the handle assembly to the end effectors. The handle assembly mainly comprises a base having the stationary finger handle and the pivotal thumb handle being pivotally connected to each other. 
     The present invention also includes the provision of a knurled knob on the sheath element for grasping the front end. The front end can be rotated to position the end effectors at various angles to the longitudinal axis during a surgical procedure. The handle assembly has a housing section defined in the base for encasing a socket bushing. The bushing having a socket capable of accepting a spherical end integral with the proximal end of the actuation element. An undercut groove in the sheath element cooperates with a threaded locking knob located in the finger handle to lock into position the front end assembly. The thumb handle controls the engagement of the front end, and makes the instrument suitable for use with disposable front ends. 
     The surgical instrument of the present invention provides numerous advantages. Because the front end is easily detachable, the handle assembly can be economically cleaned and therefore reusable. Dull and used effector ends can be discarded and replaced with fresh ones. The entire instrument need not be replaced. This provides significant cost savings over devices which must be completely replaced. The instrument is simple to manufacture, and may incorporate any one of a series of end effectors attached to the distal end of the rod for various surgical procedures. Also many moving parts normally associated with such a highly precisioned instrument are eliminated, thus reducing instances of mechanical failure requiring expensive repair or ultimate destruction of the instrument. 
     The present invention employs a spherical end at the proximal end of the actuation element to plug into a multiple prong flexible socket contained within the upper portion of the stationary handle. The front end is assembled into the handle by the user retracting the locking knob and retacting the thumb handle, then inserting the spherical end into the handle, then tightening the locking knob to secure the front end in place and then closing the thumb handle to engage the spherical end of the actuation element into the socket. The instrument is then ready for use. When desired the front end can be rotated by loosening the locking knob, rotating the front end to desired placement, and then tightening the locking knob. 
     A primary object of the present invention is to provide a surgical instrument, whereby the front end can be economically discarded upon the cutting members of the end effectors becoming worn or dull from use. 
     An important object of the present invention is to provide an endoscopic instrument that is inexpensive to manufacture. 
     Another object of the present invention is to provide a an endoscopic instrument that is easy to assemble and use. 
     Still another object of the present invention is to provide a means for connecting the actuation element to the handle, which then can be disengaged by the user merely maneuvering the thumb handle and locking knob. 
     An object of the present invention is to provide an instrument that will have a minimum number of parts requiring sterilization, especially in the handle assembly which is seldom meant to be disposable. 
     A further object of the invention is to provide an instrument with a front end that will not be inadvertently disengaged during a procedure. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing objects and other features of the invention will become readily apparent and may be understood by referring to the following detailed description of an illustrative preferred embodiment of the endoscopic surgical instrument having a novel ball and socket connection mechanism for connecting the front end of the instrument to the handle assembly. 
     FIG. 1 illustrates a side elevational view of the endoscopic instrument. 
     FIG. 2 is an exploded side elevational view of the endoscopic instrument. 
     FIG. 3 is a partial cross-section of the handle assembly with the front end assembly engaged therein. 
     FIG. 4 is a partial cross-section of the handle assembly with the front end assembly disengaged. 
     FIG. 5 is a top plan view of the base/handle section. 
     FIG. 6 is an exploded view of the spherical end and socket bushing. 
     FIG. 7 is an elevational view of the socket bushing. 
     FIG. 8 is a top view of the socket bushing of FIG. 7. 
     FIG. 9 is a front view of the socket bushing of FIG. 7. 
     FIG. 10 is a partial cross-section of the locking knob positioned within the undercut section of the sheath. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The endoscopic instrument described herein includes a handle assembly, a removable front end assembly which interconnects the handle assembly to operable end effector mechanisms. The front end assembly includes a tubular sheath element and connector element movable within the sheath. The distal end of the front end assembly may be operably connected to any number of end effectors for actuation of a surgical device. The proximal end of the front end assembly is removably and operably connected to the handle assembly for transmission to the end effector surgical device which is manually manipulated by the surgeon. The novel feature of the instrument is in the manner in which the front end is removably connected to the handle assembly. The benefits derived from the present invention would be equally applicable to laparoscopic instruments. 
     The description below refers to an endoscopic instrument in accordance with the invention. However, this description is not intended to limit the scope of the present invention, but merely to be illustrative and representative thereof. 
     Referring now to FIGS. 1 and 2, endoscopic instrument 20 includes a front end assembly 22 and a handle assembly 24 which is operably interconnectable with any linear actuated end effector mechanisms 26 that may be positioned on a distal end 32 of front end assembly 22. Front end assembly 22 includes a tubular sheath element 28 and a rod-shaped actuation element 30 cointensively and coaxially slidably disposed within the sheath 28. Distal end 32 of actuation element 30 is operably connected to end effector 26 for actuation of a surgical device. The proximal end 34 of actuation element 30 having a spherical end 36 for removably engaging with handle assembly 24. For this present invention disclosure the spherical end 36 will be shown as a ball, but it is to be appreciated that other shapes may work as well. A knurled grip 38 is integral with the front end assembly 22 near to the proximal end 34 to assist the surgeon in grasping the front end assembly 22 for purposes of engaging or disengaging it, or to rotate end effector mechanism 26 into a different angle of orientation. 
     Handle assembly 24 includes a base 45 having a downwardly depending stationary finger handle 42 serving as one section of the handle assembly 24, while the other section is represented by an articulating finger operable, movable thumb handle 44 pivotally mounted to base 45 by a pivot pin 58. The pivot pin 58, being of structure well known to the art, is therefore not detailed in the drawings. As shown in FIGS. 3-4, base 45 includes a housing section 46, having a hollow barrel-shaped bore 47 extending along a longitudinal axis within housing section 46, the bore 47 having a base opening 73 in communication with the environment. FIGS. 3-5 describe the relationship within the housing section 46 wherein a socket bushing 48 is disposed therein, having a flexible end 68 and a linkage end 70. FIGS. 6-9 depict the flexible end 68 having four finger-like resilient prongs 54 extending outwardly. The inner surfaces 51 of prongs 54 defining a passageway 53 extending to a socket opening 52 which is in communication with the bore 47. Further defined by the inner surface 51 of each prong 54 is a recess area 55. The recess areas 55 combiningly and cooperatively define a socket 50 having an inner diameter corresponding essentially to the outer diameter of the spherical end 36. The linkage end 70 of bushing 48 has a pair of generally parallel extending elongate leg sections 57. Leg sections 57 having interior surfaces 72 defining a linkage slot 56 therein. Leg sections 57 being spaced to accommodate a linkage arm 74, to be discussed further in disclosure. Circular apertures 59 are reamed through leg sections 57 in a perpendicular direction to the longitudinal axis of bushing 48. A connector rod 61 transposes through apertures 59 to rotatively contain linkage arm 74. Connector rod 61, being of such conventional design that is well known in the art, is therefore not detailed in drawings. 
     Thumb handle 44 and base 45 are pivotally connected to each other at their upper portions by a pivot pin 58. Finger handle 42 and thumb handle 44 have convenient grasping elements 60a and 60b of the closed loop design for placement of the fingers and thumb by the surgeon for scissors-like manipulation of the instrument 20. The aforementioned elongate linkage arm 74 interconnects thumb handle 44 to front end assembly 22. Linkage arm 74 having a first end disposed within linkage slot 56, a first linkage hole 76 defined in first end, which upon being aligned with circular apertures 59 of slot 56, engages rotatively with connector rod 61 of bushing 48. Linkage arm 74 further having a second end with a second hole 78 defined therein for rotatively connecting to thumb 44. The connecting method, being of conventional pin means well known to those skilled in the art, is not detailed in the drawings. Finger handle 42 includes a generally semi-circular cutout section 82 and thumb handle includes a generally triangular shaped cutout section, whereby the sections 82 and 86 cooperatively afford linkage arm 74 an area of slidingly movement therein. Extending along one of the elongated edges of linkage arm 74 is a generally straight abutment edge 80. A relatively flat surface is defined along the hypotenuse-like side 84 of thumb handle cutout section 86. Upon being retracted in relationship to finger handle 42, thumb handle 44 freely pivots about base 45 until hypotenuse-like side 84 is juxtaposed to abutment edge 80 of linkage arm 74, thereby disengaging bushing 48 from spherical end 36 of front end assembly 22. It is because of the resiliency of finger-like prongs 54, and because engagement occurs within base 45, that allows the disengagement by the surgeon merely retracting thumb handle 44. When engaged, all actuation of effector mechanism 26, is controlled by pivotal movement of thumb handle 44. 
     As shown above, front end assembly 22 is releasably attached to handle assembly 24 by a novel ball and socket arrangement. Spherical end 36 of actuation element 30 is inserted into handle assembly 24, whereby it passes through resilient elongated prongs 54 until it is fully seated within socket 50. To arrest any unwanted movement of front end assembly, either along the longitudinal axis or that of a rotational nature, a threaded locking knob 62 is disposed into a threaded opening 63 in the lower portion of base 45. FIG. 10 depicts locking knob 62 having an elongated threaded section with a contact surface 64 at one and a finger tip grip 66 on the other end. A concentric undercut section 40 is defined in an area of close proximity to proximal end 34 of tubular sheath element 28. The releasable locking-in of front end 22 to handle assembly 24 is accomplished by the user rotating the knob until contact surface 64 is tightenly seated in undercut section 40. To reorient the angle of the end effector mechanism, front end assembly 22 need not be disengaged, only locking knob 62 needs to be loosened. 
     Whereas many prior art designs utilize a spherical ball seated within a rigid clevis structure (which is generally located in the housing of the pivotal handle), the present invention utilizes a novel ball and socket arrangement, whereby the socket, bushing 48 of the present invention is located in the base portion 45 of the stationary finger handle 42 and the engagement and disengagement of the ball and socket is actuated by pivotable thumb handle 44. The unique finger like prongs 54 allow the user to easily insert spherical end 36 into socket 50. 
     The assembly of instrument 20 can be performed in the following manner; first holding handle assembly 24 by finger handle 42; then retracting thumb handle 44; then loosening locking knob 62 completely; then inserting spherical end 36 into base 45 of handle assembly 24; then closing and tightening locking knob 64 into undercut 40 of sheath 28 to secure front end assembly 22 in place; and, then closing thumb handle 44 to engage spherical end 36 into socket 50 of socket bushing 48. The instrument 20 is then ready for use. The end effector mechanism 26 may be rotated by loosening locking knob 62, then rotating front end 22 to desired placement of end effectors 26, and then retightening of locking knob 62. To remove front end 22, the thumb handle 44 is retracted, thereby disengaging spherical end 36 from socket 50, then locking knob 62 is loosened and front end 22 is removed. 
     This design provides a releasable connection that addresses the problems of ease of use, assembly and manufacture. 
     It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims. 
     LEGEND 
     20 Endoscopic Instrument 
     22 Front end Assembly 
     24 Handle Assembly 
     26 End Effector Mechanism 
     28 Tubular Sheath Element 
     30 Actuation Element 
     32 Distal end 
     34 Proximal end 
     36 Spherical End 
     38 Knurled grip 
     40 Concentric Undercut Section in Sheath 
     42 Stationary Finger Handle 
     44 Pivotable Thumb Handle 
     45 Base 
     46 Housing Section 
     47 Bore in housing section of Base 
     48 Socket Bushing 
     50 Socket 
     51 Inner surfaces of prongs 
     52 Socket Opening 
     53 Passageway defined by inner surface of prongs 
     54 Prongs 
     55 Recess area in each prong making up socket 
     56 Linkage slot in bushing 
     57 Extending leg sections (2) at actuation end of bushing 
     58 Pivot Pin 
     59 Circular apertures in leg sections of bushing 
     60a Grasping element in Finger Loop 
     60b Grasping element in Thumb Loop 
     61 Connector rod 
     62 Threaded Locking Knob 
     63 Threaded opening in base for threaded locking knob 
     64 Contact Surface of locking knob 
     66 Finger tip grip on locking knob 
     68 Flexible end of bushing 
     70 Actuation end of Bushing 
     72 Interior surface of legs sections 
     73 Base opening to bore 
     74 Linkage Arm 
     76 First linking hole 
     78 Second linking hole 
     80 Abutment edge of linkage arm 
     82 Semi-circular cutout section in finger handle 
     84 Hypothenuse side 
     86 Triangular cutout section in thumb handle