Abstract:
A trephine particularly adapted for use in surgical procedures has a universal handle having a tubular portion from which extend a plurality of circumferentially spaced fingers which removably support a tubular trephine blade. In use, the bore of the handle and blade provides a line of sight and illumination along the axis of the trephine to the inside cutting edge of the blade, while additional illumination is allowed to enter through spaces between the fingers. A trephine kit has a universal handle and a variety of different blades for use therewith.

Description:
BACKGROUND OF THE INVENTION 
     The present invention is directed to a trephine particularly adapted for use in surgical operations such as corneal transplant procedures. More particularly, the present invention relates to a trephine comprising a universal trephine handle adapted to securely and accurately hold different sizes of trephine blades and having a structure which facilitates illumination of the cutting edge and accurate positioning and manipulation thereof. 
     Trephines are used, for example, in ophthalmic surgery for corneal transplant operations and are employed in various sizes or blade diameters. In corneal transplant procedures the trephine must be precisely positioned and manipulated under a microscope by the surgeon. It is thus of great important that the cutting edge of the blade be well illuminated and that the surgeon have a clear line of sight. 
     Wherefore, it is an object of the present invention to provide a trephine having a clear line of sight along the axis thereof, so that the trephine can be accurately employed under a microscope by a surgeon without leaving the eyepiece of the microscope. Another object of the present invention is to provide a trephine which facilitates illumination of the inside cutting edge of the trephine blade to allow accurate positioning thereof. Yet another object of the present invention is to provide a trephine having a universal handle upon which different diameter trephine blades can be accurately mounted in alignment with respect to the handle. Still another object of the present invention is to provide a trephine which has minimal light reflection and is easily manipulated by the surgeon. These and other objects, features, and advantages will be apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a trephine of the present invention; 
     FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1; and 
     FIG. 3 is an exploded view illustrating the relationship of the separable members of the present invention. 
    
    
     DESCRIPTION OF THE INVENTION 
     Now referring to the figures, a trephine of the present invention is shown and generally indicated by the numeral 1. Broadly, trephine 1 comprises a universal handle 2 upon which is mounted trephine blade 4. As set forth in detail in the following disclosure, trephine blade 4 is selectively removably mounted on handle 2 and it is contemplated that trephine blades of different diameters will be provided for use with a universal handle. 
     Universal handle 2 has a generally cylindrical shape and comprises two separable members, body 6 and cylindrical barrel 8. Body 6 has a tubular cylinder 10 which has a smooth interior bore 12 at the forward portion thereof and a threaded interior bore 14 at the rearward portion thereof. As used herein &#34;forward&#34; refers to the left as viewed in the figures and &#34;rearward&#34; refers to the right as viewed in the figures. Press fit or otherwise fixedly attached to the forward end portion of cylinder 10 is ring 16 which has a knurled radially outer surface 18 to facilitate manipulation of ring 16, and hence, trephine 1. The forward end portion of cylinder 10 has a plurality of circumferentially spaced axially aligned slots 20 which are located in the radially outward surface portion of cylinder 10. Each slot 20 is sized to receive a rearward end portion 22 of a finger 24. As best shown in FIG. 2, each rearward end portion 22 of each finger 24 is clampingly retained in slot 20 by ring 16. Each finger 24 extends forwardly from cylinder 10 and has an intermediate portion 26 canted slightly from the longitudinal axis of trephine 1. Thus, the forward end portion 28 of each finger 24 is located radially inwardly with respect to the rearward end portion 22 with each forward end portion 28 and rearward end portion 22 extending generally parallel to the longitudinal axis of trephine 1. Each forward end portion 28 has a projection 30 which provides means for stopping rearward movement of blade 4. Fingers 24 are of relatively narrow width and are circumferentially spaced so as to provide open spaces 32 therebetween to allow entry of light to the hollow interior portion of trephine 1 and, hence, illuminate the inside cutting edge of blade 4. 
     Cylindrical barrel 8 has a smooth interior bore 34. 
     The radially outer surface of the longitudinally intermediate portion of barrel 8 carries threads 36 which are adapted to threadably engage threaded interior bore 14 of tubular cylinder 10. The unthreaded, forward portion 38 of barrel 8 is of reduced diameter to allow free extension through tubular cylinder 10 while the rearward end portion 40 is of enlarged diameter and has a knurled outer surface 42 to facilitate hand rotation thereof with respect to tubular cylinder 10. 
     Trephine blade 4 is also tubular in shape and has a cutting edge 44 and an interior bore 46. Bore 46 has an increased diameter portion 48 and a rearward facing shoulder 50 against which abutts the transverse, forward face of each forward end portion 28 of each finger 24. Shoulder 50 provides stop means limiting rearward movement of blade 4 functioning simultaneously with the stop means of projections 30. 
     A plurality of different trephine blades 4 of different diameters are contemplated for use with the universal handle in accordance with the present invention. For example, trephine blades having diameters of from 6.0 to 9.5 millimeters are suitable. It is contemplated that a kit of a plurality of different size blades and a universal handle will be provided thereby economically providing trephines of various sizes and also facilitating trephine use in the operating room by providing a compact kit of one handle and a plurality of blades which can easily be mounted thereon. Separate trephine blades are, of course, easily sterilized for surgical use. 
     Further understanding of the present invention will be obtained from the following description of the manipulation of trephine 1. To mount a desired trephine blade 4 onto universal handle 2, the blade 4 is placed coaxial with the forward end portions 28 of fingers 24 with barrel 8 in a rearward position. Fingers 24 are each spring loaded radially inwardly so as to be normally smaller than the inner diameter of the bore 48 of the smallest trephine blade 4. Then barrel 8 is rotated in threaded engagement with tubular cylinder 10 in a direction which urges cylinder 10 forwardly until the forward edge of unthreaded portion 38 comes into abutting relationship with the radially inner surfaces of intermediate portions 26 of each of fingers 24. After a close but slidable fit between fingers 24 and blade 4 is obtained, blade 4 is moved rearwardly to engage the stop means simultaneously provided by shoulder 50 and projections 30. Then, further rotation of barrel 8 causes the forward end portions 28 of fingers 24 to move radially outwardly to clampingly retain trephine blade 4 thereon. Blade size calibrations can be etched on either or both of fingers 24 as at 52 or barrel 8 as at 54 to indicate the proper location of barrel 8 with respect to cylinder 10 for each size trephine blade 4 to facilitate mounting of trephine blades on universal handle 2. 
     As will be appreciated by those skilled in the art, trephine 1 has a longitudinal bore providing a line of sight for a surgeon along the longitudinal axis thereof to the inside cutting edge of the trephine blade 4. Hence, in use, a surgeon does not have to remove his eye from the eyepiece of a microscope to position and use trephine 1, and microscope light passes through the longitudinal center of trephine 1 to provide illumination of the inside cutting edge of blade 4. In addition, trephine 1 has open spaces 32 which admit further light to the interior of trephine 1. Preferably the trephine of the present invention is made of stainless steel or other material suitable for use in a surgical environment and has a satin, non-glare finish for minimal light reflection. 
     It will also be appreciated that projections 30 and shoulder 50 on the interior bore of the trephine blade 4 provide secure and accurate positioning and alignment of trephine blade 4 on the forwad end portions 28 which provide means for supporting blade 4. Furthermore, the manipulation of trephine 1 is enhanced by knurled portions 18 and 42 to facilitated rotation of the parts of universal handle 2 to remove or mount a trephine blade or to hold, position and rotate trephine 1 in surgery. 
     Thus, the specific embodiment of the present invention described herein is well calculated to achieve the objects of the present invention. However, it is evident that those skilled in the art, once given the benefit of the foregoing disclosure may make modifications of the specific embodiment described herein without departing from the spirit of the present invention. Such modifications are intended to be within the scope of the present invention which is limited solely by the scope and spirit of the appended claims.