Abstract:
A highly secure instrument adapter includes a handle with an internal locking and release mechanism which does not use a pushing release and which requires little physical effort to lock and release, yet provides a stable and secure connection between an instrument and the handle. The locking mechanism is comprised an ergometric handle having an open handle cavity, a receiver having an internal threaded tubular body and a plurality of locking apertures, and a rotating collar having a limited range of rotation, a plurality of fingers that project outward from the flattened surface on a spacer structure, and a plurality of circular apertures placed alternately between said fingers.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 61/659,889 filed on Jun. 14, 2012. 
     FIELD OF INVENTION 
     The present invention relates to the field of instrument adapters for attaching medical instruments to handles, and more specifically to a highly secure instrument adapter mechanism which allows a surgeon to quickly change an instrument shaft to alter the function of the instrument during a surgical procedure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of an exemplary secured instrument adapter mechanism. 
         FIGS. 2   a  and  2   b  illustrate an exemplary receiver for a secured instrument adapter mechanism. 
         FIGS. 3   a ,  3   b  and  3   c  illustrate an exemplary sixty degree rotating collar for a secured instrument adapter mechanism. 
         FIGS. 3   d  and  3   e  illustrate critical angles and measurements of the fingers. 
         FIG. 4  illustrates an exemplary finger for a rotatable sixty degree rotating collar. 
         FIGS. 5   a  and  5   b  illustrate perspective and side views, respectively, of an exemplary thrust washer. 
         FIG. 6  illustrates an exemplary secured instrument adapter mechanism. 
         FIG. 7  illustrates an exemplary secured instrument adapter mechanism with an instrument shaft inserted in the adapter. 
         FIG. 8   a  illustrates an exemplary secured instrument adapter mechanism in its unlocked position. 
         FIG. 8   b  illustrates an exemplary secured instrument adapter mechanism in its semi-engaged position. 
         FIG. 8   c  illustrates an exemplary secured instrument adapter mechanism in its locked position. 
         FIG. 9  illustrates an exemplary rotatable sixty degree rotating collar with a slot and pin control. 
     
    
    
     BACKGROUND 
     Medical instrument handles utilize adapters to securely connect a variety of different instruments during surgical procedures. Most handles use adapters with locking and release mechanisms having intricate designs and multiple moving components. To prevent the locking and release mechanisms from damage and from exposure to bodily fluids and other debris, locking and release mechanisms are made interior to the handle. 
     Most internal release mechanisms use an external collar which is pushed inward towards the handle to release the shaft of an instrument. One limitation of these internal release mechanisms, however, is the stability of the external collar. When an external collar is bumped at a certain position with enough force, instruments are inadvertently released from the handle. A positive locking device would not cause an instrument to accidently release from the handle because of bumping or other vibrations. 
     Internal adapters known in the art also contain many components and moving parts which need to be manufactured separately and assembled. Additional parts mean additional manufacturing time and cost, as well as additional opportunities for parts to break and wear. 
     It is desirable to develop an internal release mechanism that does not use a pushing release. 
     It is desirable to develop an internal release mechanism that requires little physical effort to lock and release, yet provides a stable and secure connection between an instrument and the handle. 
     It is desirable to develop an internal release mechanism that uses positive, impact-proof locking. 
     TERMS OF ART 
     As used herein, the term “assembly” means a plurality of mechanical parts which may or may not operate interdependently to perform a mechanical function. 
     As used herein, the term “chamfer” refers to a beveled, angled or tapered edge which engages the edge of a second component to create a secured junction. 
     As used herein, the term “finger” means a flexible or non-rigid protruding structure. 
     As used herein, the term “inner contoured surface” refers to the inner surface of a finger which contains at least two distinctive sections having differing radii or angles. 
     As used herein, the term “interior receiver channel diameter” refers to the aperture in a sixty degree rotating collar which engages a receiver. 
     As used herein, the term “lead-in surface portion” refers to an initial portion of an inner contoured surface placed at an angle greater than that of a ramp surface portion. 
     As used herein, the term “locking engagement” refers to the portion of an inner contoured surface which is adapted to engage a ball bearing. 
     As used herein, the term “ramp surface portion” refers to a transitional portion of an inner contoured surface placed at an angle less than that of a lead-in surface portion. 
     SUMMARY OF THE INVENTION 
     The present invention is a highly secure instrument adapter with a rotating release rather than a pushing release. The device employs ball bearings and a small number of interlocking parts to achieve stability and positive, impact proof locking. 
     DETAILED DESCRIPTION OF INVENTION 
     For the purpose of promoting an understanding of the present invention, references are made in the text to exemplary embodiments of a secured instrument adapter mechanism, only some of which are described herein. It should be understood that no limitations on the scope of the invention are intended by describing these exemplary embodiments. One of ordinary skill in the art will readily appreciate that alternate but functionally equivalent structures and materials may be used. The inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art. Specific elements disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention. 
     It should be understood that the drawings are not necessarily to scale; instead, emphasis has been placed upon illustrating the principles of the invention. In addition, in the embodiments depicted herein, like reference numerals in the various drawings refer to identical or near identical structural elements. 
     Moreover, the terms “substantially” or “approximately” as used herein may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. 
       FIG. 1  is an exploded view of an exemplary embodiment of a highly secure instrument adapter  100 . As illustrated, highly secure instrument adapter  100  includes receiver  10 , rotating collar  30 , thrust washer  50 , interconnect tube  60 , handle core  65  that ends in cap  66 , locking ball bearing  70 , stabilizing ball bearings  92  and compression spring  94 . Handle  80  secures receiver  10 , rotating collar  30 , thrust washer  50 , interconnect tube  60 , handle core  65  with cap  66 , ball bearing  70 , stabilizing ball bearings  92  and compression spring  94 . In the exemplary embodiment shown, handle  80 , with handle cavity  82 , is illustrated as a simple handle designed to be easily grasped by one hand. However, in further exemplary embodiments, handle  80  may be any handle known in the art, including, but not limited to, torque-limiting handles. 
       FIGS. 2   a  and  2   b  illustrate an exemplary receiver  10  in more detail. In the exemplary embodiment shown, receiver  10  is an internal threaded tubular body  11  with flat outside end surface  12  at the front of receiver  10  and centralized shaft cavity  15  creating a tubular passage completely through receiver  10 . Receiver  10  is adapted to receive the shaft of a medical instrument so that the medical instrument shaft may slide within centralized shaft cavity  15 . 
     Receiver  10  also includes four locking apertures  18   a  ( 18   b ,  18   c  and  18   d  not shown) approximately half way up internal threaded tubular body  11  from flat outside end surface  12 . Locking apertures  18   a  ( 18   b ,  18   c  and  18   d  not shown) are configured to engage locking ball bearing  70  (not shown). In the exemplary embodiment shown, receiver  10  includes four equidistant and symmetrically arranged locking apertures  18   a  ( 18   b ,  18   c  and  18   d  not shown). However, in further exemplary embodiments, receiver may contain more or fewer locking apertures. In still further exemplary embodiments, locking apertures may not be equidistant from each other or may not be symmetrically arranged around internal threaded tubular body  11 . In yet further exemplary embodiments, locking apertures  18   a  ( 18   b ,  18   c  and  18   d  not shown) may be at a different distance along internal threaded tubular body  11 . 
     In the embodiment shown, receiver  10  also includes an additional stabilizing aperture (not shown) in the top end of internal threaded tubular body  11  near flat outside end surface  12  that is designed to house at least one stabilizing ball bearing  92  and compression spring  94 . 
       FIGS. 3   a ,  3   b  and  3   c  illustrate an exemplary rotating collar  30 .  FIG. 3   a  is a perspective view of rotating collar  30 , illustrating radial frictional contours  32  around the perimeter of rotating collar  30 . Rotating collar  30  includes at least one stabilizing ball bearing groove  31  that partially spans the inner surface of rotating collar  30 . Receiver channel  34  runs the length of rotating collar  30  and has an internal diameter just larger than the external diameter of receiver  10  (not shown). In the exemplary embodiment shown, rotatable rotating collar  30  has an overall diameter just larger than the diameter for the front portion of handle  80  (not shown) near handle cavity  82  (not shown), so that handle  80  (not shown) is in contact with handle-contacting surface  38 . 
     It is critical that one or more stabilizing design components and structures be utilized to ensure that instrument shaft  90  is stabilized and resistant to axial, transverse and angular movement during a surgical procedure. 
     In the exemplary embodiment shown, a stabilizing ball bearing assembly is utilized as the stabilizing component. In this exemplary embodiment, stabilizing ball bearings  92  and compression spring  94  exert a force to instrument shaft  90  when instrument shaft  90  is inserted into shaft cavity  15  and rotating collar  30  is rotated. When rotated collar  30  is rotated, a transverse force is applied to instrument shaft  90  by compressing compression spring  94  which engages a stabilizing ball bearing  92  against instrument shaft  90 . Rotating collar  30  includes at least one stabilizing contoured ball bearing groove  31  that partially spans the inner surface of rotating collar  30 . Stabilizing contoured ball bearing groove  31  is contoured so that it has a graduated variance in depth. Maximum force is applied to instrument shaft  90  when stabilizing ball bearing  92  is in contact with the shallowest portion of stabilizing contoured ball bearing groove  31 . 
     In various embodiments, alternative stabilizing components such as springs, cams, contoured member, interlocking members, threaded components, protruberances and friction or pressure inducing members may be utilized to prevent movement of instrument shaft  90  during a surgical procedure. These alternatives may or may not be functionally equivalent to stabilizing ball bearing and spring assembly 
     Also illustrated in  FIG. 3   a , on the inner surface of rotating collar  30 , around receiver channel  34 , rotating collar  30  includes an inward projection  36 , which is designed to be in physical contact with the inner walls of handle cavity  82  (not shown) and terminates in flattened surface  37 . In the exemplary embodiment shown, inward projection  36  creates receiver channel  34  having an interior diameter of 0.540 inches. 
     As illustrated in  FIGS. 3   a ,  3   b  and  3   c , rotating collar  30  also includes a plurality of fingers  40   a ,  40   b ,  40   c , and  40   d  which project outward from flattened surface  37 . In the exemplary embodiment shown, fingers  40   a ,  40   b ,  40   c  and  40   d  project 0.290 inches from flattened surface  37  and are 0.125 inches long. The length of fingers  40   a ,  40   b ,  40   c  and  40   d  however, may vary, as it is the radial measurement of contoured inner surface  47  portions which determine the exact length of fingers  40   a ,  40   b ,  40   c  and  40   d.    
     As illustrated, spacer structure  39 , a thinned down, flexible piece of material, holds fingers  40   a ,  40   b ,  40   c  and  40   d  a distance away from flattened surface  37 . In the exemplary embodiment shown, spacer structure  39  is approximately 0.019 inches thick. 
     Alternating between fingers  40   a  and  40   b ,  40   b  and  40   c , and  40   c  and  40   d  are circular apertures  44   a ,  44   b  and  44   c , respectively. As illustrated in  FIG. 3   b , apertures  44   a  and  44   c  are identical and smaller than aperture  44   b.    
     Looking specifically at fingers  40   a ,  40   b ,  40   c  and  40   d , in the exemplary embodiments shown, each finger  40   a ,  40   b ,  40   c  and  40   d  has outer surface  45 , which is curved at a consistent radius, and smooth inner surface  46 , which is also curved at a consistent radius. 
     Approximately halfway along fingers  40   a ,  40   b ,  40   c  and  40   d , however, smooth inner surface  46  transitions to inner contoured surface  47 , which creates a tapered portion of fingers  40   a ,  40   b ,  40   c  and  40   d  with narrow end  48  gradually transitioning to wider end  49 . As illustrated most visibly in  FIG. 3   b , contoured inner surface  47  of fingers  40   a ,  40   b ,  40   c  and  40   d  is not a consistent radius. 
     In the exemplary embodiments shown, contoured inner surface  47  consists of three distinct portions, each having a distinct critical angle or radius. First is lead-in surface portion  47   a , near narrow end  48 , which transitions to ramp surface portion  47   b . Rample angle surface portion  47   b  is flatter. Finally, locking engagement  47   c , near wider end  49 , is contoured to the radius of locking ball bearing  70  (not shown). 
     In further exemplary embodiments, rotating collar  30  may contain more or fewer fingers, and fingers may be differently spaced around flattened surface  37 . In still further exemplary embodiments, fingers may be different dimesions, and the radii of contoured inner surfaces may differ to correspond to variations in receiver  10  (not shown) diameter or receiver channel  34  diameter. 
     However, it is desirable to have as few parts and components as possible for manufacturing, while still maintaining the desired locking and securing properties. Four fingers strikes an appropriate balance between complexity in manufacturing and functionality. 
       FIGS. 3   d  and  3   e  illustrate the critical angles and measurements of fingers  40 . Lead-in surface portion  47   a  is placed at an angle of approximately 109.114 degrees as measured from the centerline A of receiver channel  34 . This angle is illustrated as θ A  in  FIG. 3   d . Ramp surface portion  47   b  is placed at an angle of 86.502 degrees as measured from the centerline A of receiver channel  34 . This angle is illustrated as θ B  in  FIG. 3   d.    
     Locking engagement  47   c  has a radius of 0.070, which is also the radius of locking ball bearing  70  (not shown). In order to securely and stably engage, locking engagement  47   c  and locking ball bearing  70  (not shown) must have corresponding radii. 
     In further exemplary embodiments, the exact angles of lead-in surface portion  47   a  and ramp surface portion  47   b , as well as the radius of locking engagement  47   c , may vary slightly. For example, the angle of ramp surface portion  47   b  is 86.052 degrees, but may vary by plus or minus 20 degrees. This allows for gradual engement of a instrument shaft and an increase in pressure on the specific finger  40  which is touching a locking ball bearing  70  (not shown). The angle of lead-in surface portion  47   a  may similarly vary by plus or minus 20 degrees. However, the exact radial measurement for locking engagement  47   c  may vary within an amount determined by the diameter and shape of locking ball bearing  70  (not shown), as the two radii must properly correspond to provide secure and stable engagement. 
     As illustrated in  FIG. 3   e , there is a distance of approximately 42.642 degrees, illustrated as θ C , between each finger  40   a ,  40   b ,  40   c  and  40   d , with each finger  40   a ,  40   b ,  40   c  and  40   d  being approximately 47.358 degrees in ramp and engagement length. Further, finger  40   a  is shifted approximately 10.679 degrees from center, such that 36.679 degrees (θ D ) of finger  40   a  occurs counterclockwise from 0 degrees. As illustrated in  FIG. 3   b , each subsequent finger  40   b ,  40   c ,  40   d  is shifted approximately 10.670 degrees from 90 degrees, 180 degrees, and 270 degrees, respectively, to be equally spaced along flattened surface  37 . 
     In still further exemplary embodiments, fingers  40   a ,  40   b ,  40   c  and  40   d  may be separated by between 20 and 70 radial degrees, depending on the number and size of fingers required or desired. For example, some exemplary embodiments may use between 2 and 8 fingers; the more fingers, the closer together fingers will be. 
       FIG. 4  illustrates an exemplary finger  40  in further detail. Finger  40  has outer surface  45  and smooth inner surface  46 , each having a consistent radius corresponding to the inner and outer radii of outward projection  36  (not shown). Contoured inner surface  47  creates a tapered finger with a narrow end  48  and wider end  49  with its inconsistent radius. As illustrated, contoured inner surface  47  is divided into three sections, each having a different radius. Lead-in surface portion  47   a  has a larger radius, resulting in a steep ramp, while ramp surface portion  47   b  has a smaller radius, resulting in a flatter portion. Locking engagement  47   c  has a radius corresponding to that of locking ball bearing  70  (not shown). 
       FIGS. 5   a  and  5   b  illustrate perspective and side views, respectively, of an exemplary thrust washer  50 . 
       FIG. 6  illustrates an exemplary highly secure instrument adapter  100  fully assembled without an instrument shaft. Receiver  10  is in receiver channel  34  (not shown) of rotating collar  30 , with internal threaded tubular body  11  adapted to engage threads on the exterior of interconnect tube  60 . Fingers  40  correspond to apertures  18  of receiver  10 , and thrust washer  50  is secured against the inner surfaces of fingers  40 . Both ends of interconnect tube  60  contain exterior threads, with the anterior end of interconnect tube  60  attaching to internal threaded tubular body  11 , and the posterior end of interconnect tube  60  attaching to handle core  65  (not shown) inside handle cavity  82  (not shown). Handle core  65  slides into handle cavity  82  from the posterior end of handle  80  (not shown) and is secured to handle  80  by its connection to interconnect tube  60  within handle cavity  82 . The posterior end of handle core  65  widens to form a cap  66  (not shown) that fits against the posterior end of handle  80  and covers the posterior end of handle cavity  82 . 
     Also illustrated in  FIG. 6  are the internal contours of shaft cavity  15 . Just inward from apertures  18  in the exemplary embodiment shown, centralizing chamfers  25  are triple square. However, in further exemplary embodiments, centralizing chamfers  25  may be any configuration, such as double square or hexagonal, to correspond to a particular instrument shaft. Interconnect tube  60  fits within end cavity  28  (not shown) of receiver  10 . 
       FIG. 7  illustrates an exemplary highly secure instrument adapter  100  with instrument shaft  90  inserted and secured in shaft cavity  15 . As illustrated, instrument shaft  90  contains groove  93  which runs the circumference of instrument shaft  90  and engages stabilizing ball bearing  92 . 
       FIGS. 8   a ,  8   b  and  8   c  illustrate an exemplary adapter&#39;s  100  securing mechanism. 
       FIG. 8   a  shows highly secure instrument adapter  100  at rest. Locking ball bearing  70  is in one of apertures  44 , which are halfway between fingers  40 . Locking ball bearing  70  is freely rotatable in aperture  44 . As rotating collar  30  is rotated relative to instrument shaft  90  in a clockwise direction locking ball bearing  70  begins to be tightened between finger  40  and instrument shaft  90 . 
     Because finger  40  is flexibly connected to rotating collar  30  at spacer structure  39  (not shown), finger  40  begins to flex outward from instrument shaft  90  as locking ball bearing  70  moves from lead-in surface portion  47   a  through ramp surface portion  47   b , as illustrated in  FIG. 8   a . As rotating collar  30  is rotated, the amount of force required to rotate rotating collar  30  increases. 
     Once locking ball bearing  70  reaches locking engagement  47   c , the final change of radius along contoured inner surface  47 , locking ball bearing  70  locks into locking aperture  18  between instrument shaft  90  and finger  40 , as illustrated in  FIG. 8   c.    
     In the exemplary embodiments shown, instrument shaft  90  has groove  93  (not shown) around its circumference and aligned with locking ball bearing  70  when inserted into highly secure instrument adapter  100 . When in the locked position, as illustrated in  FIG. 8   c , locking ball bearing  70  pushes inward on instrument shaft  90 , and is locked in groove  93  (not shown), thereby preventing instrument shaft  90  from being pulled outward from handle  80  (not shown). 
     To release instrument shaft  90 , rotatable rotating collar  30  is forcibly rotated counterclockwise relative to instrument shaft  90 , returning securing mechanism to its resting, or unlocked, position as illustrated in  FIG. 8   a . The flexibility provided by spacer structure  39  (not shown), which flexibly connects fingers  40  to rotating collar  30 , allows a user to force locking ball bearing  70  out of locking engagement  47   c  to release instrument shaft  90 . 
     The flexibility of spacer structure  39 , and the rotating design of highly secure instrument adapter  100 , also makes the locking functions impact-proof. For example, bumping instrument shaft  90  in any direction will not shake or move locking ball bearing  70  from the locked position, but may cause locking ball bearing  70  to flex finger  40  relative to instrument shaft  90 , while locking ball bearing  70  remains in its locked position (engaging locking engagement  47   c ). 
     As illustrated in the exemplary embodiments shown in  FIGS. 8   a ,  8   b  and  8   c , it takes very little rotating to go from unlocked ( FIG. 8   a ) to locked ( FIG. 8   c ). The high radius of lead-in surface portion  47   a  of finger  40  causes locking ball bearing  70  to travel a greater distance over a smaller amount of rotation. Specifically, in the exemplary embodiment described, it is approximately 60 degrees from unlocked to locked position. In other words, it is 60 degrees from the center of locking ball bearing  70  at its resting position to the center of locking engagement  47   c . However, in further exemplary embodiments, highly secure instrument adapter  100  may be designed with approximately 50-70 degrees of rotation required between the unlocked and locked positions. 
     The exemplary embodiment described in  FIGS. 8   a ,  8   b  and  8   c  uses a single locking ball bearing  70 . However, in further exemplary embodiments, four locking ball bearings  70  may be used to provide additional locking and securing stability for instrument shaft  90 . 
     In the exemplary embodiments described, locking ball bearing  70  moves quickly over lead-in surface portion  47   a , and then moves gradually over ramp surface portion  47   b  to locking engagement  47   c . Both fast and gradual motion is needed because, if all fingers  40  only provided gradual motion, fingers  40  would need to be longer and there would not be space for four, or even two or more, fingers  40 . 
     With too gradual of motion, it would also require over 60 degrees of rotation to get ball bearing  70  to engage locking engagement  47   c . It is desirable to have as little rotation required as possible. 
       FIG. 9  is an exemplary embodiment of rotating collar  30  with slot and pin control.