Abstract:
A medical retrieval device used to remove objects such as urinary and biliary calculi from the body comprising a handle assembly with an independent rotational means, a sheath, and an object entrapping assembly. In preferred embodiments, the handle assembly comprises a longitudinally stationary base portion and a thumb slide actuation means. The longitudinally stationary portion comprises a handle base and a rotating means. In a preferred embodiment, a portion of the thumb slide actuation means is located between the distal and proximal ends of the handle base portion during the complete actuation cycle. Actuation of the thumb slide relative to the handle base causes the object entrapping assembly to be actuated between the open and closed positions. Rotation of the rotating means relative to the handle base causes precise rotation of the object entrapping assembly. The thumb slide actuation means and rotating means are separate and independent of each other, preventing inadvertent adjustment of the degree of actuation during rotation and preventing inadvertent adjustment of rotational position during actuation.

Description:
[0001]    This application claims priority to U.S. Provisional Application No. 60/303,114, entitled Medical Device Handle with Rotational Feature, with Mark R. Bilitz as the inventor, and filed on Jul. 5, 2001. This application is also related to design Pat. No. U.S. 457,955 S, issued May 28, 2002, invented by Mark Bilitz and to the utility patent application entitled, Medical Retrieval Device With Cable Protection Means, filed on Jul. 3, 2002, with inventors Stuart J. Lind and Mark R. Bilitz. The above applications are incorporated herein by reference. 
     
    
     
       BACKGROUND  
         [0002]    1. Field of Invention  
           [0003]    This invention relates to medical retrieval devices for removing objects from a body, particularly calculi from the urinary and biliary systems.  
           [0004]    2. Description of Prior Art  
           [0005]    Medical instruments are currently in use which reduce the invasiveness and potential trauma previously associated with various medical procedures. One such procedure is the removal of objects, such as kidney stones and gallstones, from the body. Various surgical devices are available which allow objects to be removed from the body without requiring major surgery. One type of surgical device is a mechanical retrieval device. Typically, such instruments consist of 2 or more flexible elements that are joined at their proximal ends and may or may not be joined at their distal ends. The flexible elements are formed in the shape of a basket, cage, grasper, or other entrapping configuration. This basket is attached to a drive wire that passes through the lumen of a small diameter (typically 2.3 mm (7.0 Fr) or less) flexible sheath, which is usually greater than 50 cm in length. The proximal ends of the sheath and drive wire are attached to a multi-part handle, normally constructed of thermoplastic materials, which can typically be operated by the user with a single hand. By manipulating the handle, the drive wire can be pulled back relative to the sheath, collapsing the basket as it retracts into the sheath. In this closed position, the sheath can be passed through the working channel of an endoscope to the proximity of the object to be removed within the patient&#39;s body. The basket is expanded to the open position by manipulating the handle, which remains outside the endoscope and the patient&#39;s body. The device is then manipulated using the handle until the object becomes enclosed within the basket. This manipulation may include advancing, withdrawing and/or rotating the basket in order to get the object to pass between the flexible elements that comprise the basket. When the object has been successfully engaged within the basket, the endoscope and the retrieval device containing the object are then simultaneously removed from the body.  
           [0006]    A number of designs for the handle of medical retrieval devices are in use. Typically, these handles consist of two main elements, a handle base and an actuation mechanism. The sheath is attached to one of these elements, and the drive wire is attached to the other. By moving the actuation mechanism relative to the handle base, the basket can be retracted into the sheath and extended from it. The handle design that appears to be preferred, based on actual current use and sales volumes, is of a thumb slide design. This design features a main handle base that remains stationary and a thumb slide actuator that slides along a portion of the handle body and has a thumb pad. This handle is held in one hand by wrapping the four fingers of the hand partially around the handle base. The thumb of the same hand is placed on the thumb pad. The device is actuated in one direction by moving the thumb pad away from the proximal end of the handle base, and in the other direction by moving the thumb pad toward the proximal end of the handle base. This type of handle can normally be held in such a way that the range of motion of the thumb required to fully actuate the device is located in a natural and comfortable area near the thumb&#39;s resting position. Since considerable skill and dexterity can be required of the user in order to retrieve an object, user comfort is of primary importance.  
           [0007]    There are many variations of the thumb slide handle in use. However, these and other prior art handle designs do not have a mechanism for rotating the basket to facilitate capturing the object. Rotation can only be accomplished by rotating the entire handle. This method has a number of disadvantages. By rotating the entire handle, the user must accordingly rotate their hand. Since the hand would initially be placed in a natural position, the position of the hand after rotation would not necessarily be comfortable for further manipulation of the handle. Again, user comfort is significant due to the considerable skill and dexterity needed to successfully complete a stone retrieval procedure. Additionally, since the entire handle must be rotated in order to rotate the basket, the sheath must rotate as well as the drive wire. This is a disadvantage because the friction between the sheath and the endoscope&#39;s working channel can prevent a smooth 1:1 torque ratio between the handle and the basket. This is particularly relevant when the endoscope is flexible and is in an articulated position. Lack of precise rotational control can increase the difficulty of engaging the object in the basket, thereby lengthening the procedure.  
           [0008]    Certain handle designs have been used which allow rotation of the basket without rotating the entire handle and thus the sheath as well. U.S. Pat. No. 4,046,150 (1977) to Schwartz et al. discloses a retrieval basket with such a handle. This handle has a first member that is attached to the sheath. A second member, which is attached to the drive wire, is located at the proximal end of the first member. The device is actuated by sliding the second member into and out of the first member, which is held stationary. The basket is rotated relative to the sheath by rotating the second member relative to the first member. However, this handle is not of the preferred thumb slide style, and requires the use of two hands to actuate. Also, the actuational and rotational controls are not independent of each other.  
           [0009]    U.S. Pat. No. 5,957,932 (1999) to Bates et al. discloses a retrieval basket with yet another type of handle. This handle is of a pistol grip style, with a control knob located at the proximal end of the handle. The sheath is attached to the main body of the handle, and the drive wire is attached to the control knob. The device is actuated by pulling the control knob out from the main body of the handle and pushing it in. The control knob can also be rotated to rotate the basket. When the trigger portion of the handle is squeezed, mechanical advantage is applied to the actuation of the device. This design has several disadvantages. It requires two hands for normal actuation. And since the control knob is used for both actuation and rotation of the basket, the actuation and rotation are not independent of each other. It also uses a larger number of parts than other handle designs and is therefore is more complex and more expensive to manufacture. The above patents to Schwartz and Bates are incorporated herein by reference.  
           [0010]    Another type of prior art handle, which is not referenced in any patents, is shown in FIGS. 7 and 8. A handle assembly  190  consists of a stationary portion or handle base  110  and a thumb slide  130  with a thumb pad  131 . Handle base  110  has a distal end  181 , a proximal end  182 , and a length  180 . Thumb slide  130  fits partially within handle base  110  and extends out from distal end  181 , with thumb pad  131  remaining beyond distal end  181 . A hollow tube or sheath  150  has a working length  186  and is attached to thumb slide  130 . A drive wire (not shown) passes through the lumen of sheath  150  attaches at the proximal end to handle base  110  and at the distal end to a basket  160 . To operate this device, handle base  110  is held in one hand with the four fingers of the hand. The thumb of the same hand is placed on thumb pad  131 . When the thumb is extended away from the hand, thumb slide  130  slides out from distal end  181  of handle base  110 . This results in the device being in the closed position, as shown in FIG. 7. When the thumb is pulled back toward the hand, thumb pad  131  slides toward distal end  181  of handle base  110 . This results in sheath  150  being pulled back to expose basket  160 . When thumb pad  131  is pulled back completely to handle base  110 , the device is in the open position, as shown in FIG. 8. To rotate basket  160 , handle base  110  is rotated relative to thumb slide  130 . This design has the disadvantage that the actuation mechanism and the rotation mechanism are not independent. Both actuation and rotation are achieved by movement of the thumb slide and the handle base relative to each other. This design also has the disadvantage that the thumb pad is located beyond the distal end of the stationary handle base. This is a disadvantage because manipulation of the thumb slide is done with the user&#39;s thumb extended away from the hand in a somewhat awkward position, which results in less than ideal tactile control over the actuation of the device.  
           [0011]    The prior art handle designs that do allow rotation of the basket without rotating the entire handle have the disadvantage that the rotation mechanism and actuation mechanism are not independent. As a result, while the basket is being rotated, it may be inadvertently and undesirably expanded or retracted, or while it is being expanded or retracted, it may be inadvertently and undesirably rotated. The retrieval of an object from within a patient&#39;s body using an endoscope and a retrieval device is a precise and delicate procedure that requires considerable user skill and dexterity. Since the user&#39;s control of the basket is limited by the handle of the device, it is desirable that the handle allows precise and independent control of both the actuation and rotation of the basket, and is comfortable to use.  
         SUMMARY OF THE INVENTION  
         [0012]    A medical retrieval device used for extracting objects such as urinary and biliary calculi from the body comprising a handle assembly with an independent rotational means, a sheath, and an object entrapping assembly. In preferred embodiments, the handle assembly comprises a longitudinally stationary base portion and a thumb slide actuation means. The longitudinally stationary portion comprises a handle base and a rotating means. In a preferred embodiment, a portion of the thumb slide actuation means is located between the distal and proximal ends of the handle base portion during the complete actuation cycle. Actuation of the thumb slide relative to the handle base causes the object entrapping assembly to be actuated between the open and closed positions. Rotation of the rotating means relative to the handle base causes precise rotation of the object entrapping assembly. The thumb slide actuation means and rotating means are separate and independent of each other, preventing inadvertent adjustment of the degree of actuation during rotation and preventing inadvertent adjustment of rotational position during actuation.  
           [0013]    An object and advantage of preferred embodiments of the invention is to provide a medical retrieval device with a mechanism for precisely rotating the basket that is independent of the actuation mechanism.  
           [0014]    An object and advantage of preferred embodiments of the invention is to provide a medical retrieval device with a mechanism for rotating the basket that cannot inadvertently cause adjustment to the degree of actuation during rotation.  
           [0015]    An object and advantage of preferred embodiments of the invention is to provide a medical retrieval device that permits rotation of the basket without requiring rotation of the entire handle assembly and/or the sheath.  
           [0016]    An object and advantage of preferred embodiments of the invention is to provide a novel handle for a medical retrieval device that is of a thumb slide actuated type that is comfortable for the user to hold and operate.  
           [0017]    An object and advantage of preferred embodiments is to provide a novel handle for a medical retrieval device that uses a minimal number of parts, reducing cost and simplifying assembly.  
           [0018]    Further objects and advantages of preferred embodiments of the medical retrieval device described herein are that such preferred embodiments are safe, reliable, and easy to use. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is an isometric view of the preferred embodiment of the present invention.  
         [0020]    [0020]FIG. 2 is an exploded isometric view of FIG. 1.  
         [0021]    [0021]FIG. 3 is a top view of FIG. 1 showing the basket in the retracted, closed, or collapsed position.  
         [0022]    [0022]FIG. 4 is a top view of FIG. 1 showing the basket in the extended, open, or expanded position.  
         [0023]    [0023]FIG. 5 is a bottom view of FIG. 1 showing the basket in the extended, open, or expanded position.  
         [0024]    [0024]FIG. 5A is a cross sectional view of FIG. 5 taken on line A-A.  
         [0025]    [0025]FIG. 5B is a cross sectional view of FIG. 5 taken on line B-B.  
         [0026]    [0026]FIG. 6 is a side view, partially in section along the longitudinal axis, of the handle assembly portion of the medical retrieval device in FIG. 1.  
         [0027]    [0027]FIG. 6A is an enlarged view of the proximal portion of the handle assembly in FIG. 6.  
         [0028]    [0028]FIG. 6B is an enlarged view of the mid portion of the handle assembly in FIG. 6.  
         [0029]    [0029]FIG. 6C is an enlarged view of the distal portion of the handle assembly in FIG. 6.  
         [0030]    [0030]FIG. 7 is side view of a prior art medical retrieval device showing the basket in a retracted position, the top view and bottom view being the same.  
         [0031]    [0031]FIG. 8 is a side view of the same prior art device in FIG. 7 but showing the basket in an extended position, the top view and bottom view being the same. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0032]    FIGS.  1  to  6 C show a preferred embodiment of the invention. A medical retrieval device has a handle assembly  90 , which has a longitudinal axis  11 . Handle assembly  90  is comprised of an elongate handle base  10 , a rotation means or spinner  20 , a sliding portion or thumb slide  30 , and a pin  40 , all of which are preferably constructed of thermoplastic materials. Handle base  10  has a proximal end  82 , a distal end  81 , and a length  80 , which is between 5 and 20 cm. Handle base  10  is essentially hollow along longitudinal axis  11 , with an internal bore and an opening  12  at distal end  81 . A longitudinal slot having a narrow portion  14   a  and a wide portion  14   b  is located on the top surface of handle base  10 . Wide portion  14   b  has a proximal end  15  and a distal end  16 . Narrow portion  14   a  extends from proximal end  82  of handle base  10  to wide portion  14   b . Distal end  16  of wide portion  14   b  is located proximal to distal end  81  of handle base  10 .  
         [0033]    Thumb slide  30  has a thumb pad  31  and a guide portion configured as a fin  33 , which has an upper portion  33   a  and a lower portion  33   b . The width of upper portion  33   a  of fin  33  is wider than the width of narrow portion of slot  14   a  and narrower than the width of wide portion of slot  14   b . The width of lower portion  33   b  of fin  33  is wider than the width of wide portion of slot  14   b . A through hole  32  passes through lower portion  33   b  of fin  33  longitudinally. Thumb slide  30  is located on handle base  10  with upper portion  33   a  of fin  33  located within wide portion of slot  14   b  and lower portion  33   b  of fin  33  located within the hollow portion of handle base  10  below wide portion  14   b . With thumb slide  30  engaged with wide portion of slot  14   b  in this manner, thumb slide  30  can be readily moved so that fin  33  is in any position within wide portion of slot  14   b  between proximal end  15  and distal end  16 , but cannot inadvertently be removed vertically or longitudinally from wide portion of slot  14   b  in handle base  10 . Handle base  10  also limits rotational movement of thumb slide  30 . The total length of longitudinal travel of thumb slide  30  relative to handle base  10  is preferably 5 cm or less. Thumb pad  31  is located between proximal end  82  and distal end  81  of handle base  10 . The actuation of thumb pad  31  overlaps the area between proximal end  82  and distal end  81  of handle base  10 . A tube or sheath  50  has a proximal end  51 , a distal end  52 , and may be constructed of polyimide, PTFE, or other flexible material or combination of materials, and has a lumen through its entire length. Sheath  50  has a working length  86  that is preferably between 65 and 125 cm, and the diameter of sheath  50  is preferably approximately 1 mm or less. Sheath  50  passes through opening  12 , which is substantially larger in diameter than sheath  50 . Proximal end  51  of sheath  50  passes into through hole  32  in thumb slide  30  and is secured to thumb slide  30  using adhesive or other means.  
         [0034]    Spinner  20  has a knob portion  24  and a cylindrical portion  23  that has a groove  22  extending around its circumference. Spinner  20  is located at proximal end  82  of handle base  10 , with cylindrical portion  23  located within the hollow space of handle base  10  and knob portion  24  of spinner  20  located at proximal end  82  of handle base  10 . A hole  21  is located in cylindrical portion  23  along longitudinal axis  11 , and extends part way through spinner  20 . Knob portion  24  of spinner  20  is axially positioned, and has a diameter  79  that is preferably 1.5 cm or less. Pin  40  has a head  41  and a tip  42 . Pin  40  fits snugly into a hole in handle base  10 , and tip  42  of pin  40  fits into groove  22 . The length of pin  40  is such that when pin  40  is fully seated in the hole with head  41  contacting handle base  10 , tip  42  extends into groove  22  in spinner  20 , but does not fit snugly in groove  22 . Thus spinner  20  is rotatably attached to handle base  10 . This configuration limits the longitudinal movement of spinner  20  relative to handle base  10 , but permits spinner  20  to rotate freely about longitudinal axis  11  relative to handle base  10 .  
         [0035]    A drive wire  70  has a proximal end  71  and a distal end  72 . An object entrapping assembly or basket  60  is connected to distal end  72 . Basket  60  consists of a number of outwardly disposed flexible elements that form a space for entrapping objects. Drive wire  70  may be constructed or formed of stainless steel, nickel titanium alloy, or another metal. Drive wire  70  slidably extends through the lumen of sheath  50 , with proximal end  71  of drive wire  70  extending past proximal end  51  of sheath  50 . Proximal end  71  of drive wire  70  fits into hole  21  in spinner  20  and is secured using adhesive or other means. Handle assembly  90  has a longitudinally stationary portion that comprises handle base  10 , spinner  20 , and pin  40 .  
         [0036]    To operate the device, the user wraps four fingers of one hand partially around handle base  10 , but not overlapping thumb pad  31 . The tip of the thumb of the same hand is placed on thumb pad  31 . Referring to FIGS. 1 and 4, basket  60  is in the open or expanded position. In this position, thumb pad  31  is located at proximal end  15  of wide portion of slot  14   b . To actuate the device to the closed or retracted position, the user extends the thumb outward from the hand while maintaining contact between the thumb and thumb pad  31  and keeping handle base  10  stationary in the hand. This action causes thumb slide  30  to slide within wide portion of slot  14   b  toward distal end  16  of wide portion of slot  14   b  (arrow  55   a ). This longitudinal movement of thumb slide  30  relative to handle base  10  propels sheath  50  over drive wire  70  (arrow  65   b ). This enables longitudinal movement of sheath  50  relative to basket  60 , forcing basket  60  to collapse and become enclosed within sheath  50 . When thumb slide  30  rests at distal end  16  of wide portion of slot  14   b , basket  60  is in the completely closed or retracted position within sheath  50 , as shown in FIG. 3. If, for example, the object the device is being used to retrieve is a ureteral calculus, the device is introduced in this retracted position through the working channel of an endoscope into the ureter until the retracted basket emerges from the tip of the endoscope in the proximity of the calculus. The user then pulls the thumb back toward the hand, sliding thumb pad  31  back toward proximal end  16  of wide portion of slot  14   b  (arrow  55   a ). This action pulls sheath  50  back relative to drive wire  70  and basket  60  (arrow  55   b ). Basket  60  is then exposed and resumes its expanded shape, as shown in FIGS. 1 and 4.  
         [0037]    Handle assembly  90  is then manipulated in order to entrap the object within basket  60 . Longitudinal manipulation of basket  60  relative to the object is accomplished by pushing or pulling handle assembly  90  along longitudinal axis  11 . Rotational positioning of basket  60  is accomplished by grasping knob  24  of spinner  20  with the thumb and forefinger of the user&#39;s second hand, and rotating spinner  20  about longitudinal axis  11  (arrow  65   a ), relative to handle base  10 , which is kept stationary with the first hand. This causes drive wire  70  to rotate within sheath  50 , and basket  60  to rotate relative to sheath  50  the same amount in the same direction (arrow  65   b ). Once the object has been engaged within basket  60 , the user then pushes thumb pad  31  forward part way toward distal end  16  of wide portion of slot  14   b  until basket  60  is partially closed in order to securely hold the object. The device and the endoscope are then simultaneously withdrawn from the patient, holding thumb pad  31  stationary relative to handle base  10  to keep the object secured within basket  60 .  
         [0038]    It can be seen from the above description that the medical retrieval device according to this invention has a mechanism for precisely rotating the basket that is independent of the extension and retraction actuation mechanism used to collapse and expand the basket. This permits rotation of the basket without requiring the user to rotate the entire handle assembly, allowing for improved user comfort. This also permits rotation of the basket without requiring the sheath to rotate within the working channel of the endoscope, thereby allowing more precise control of basket rotation. The handle base isolates the spinner from the thumb slide actuator. This prevents inadvertent longitudinal actuation of the basket during rotation and inadvertent rotation of the basket during longitudinal actuation. It can also be seen that the handle assembly is of a thumb slide actuated type that is comfortable for the user to hold and operate. It can further be seen that the handle uses a minimal number of parts, reducing cost and simplifying assembly. This gives the desirable result of a handle assembly of a preferred style that allows precise and separate control of the actuation and rotation of the basket, and is comfortable for the user to hold and operate.  
         [0039]    Another aspect of the invention is the method of manufacturing the medical retrieval device as described above. More specifically, the method involves steps of injection molding a handle with the above characteristics and assembling the device whereby the device has a rotational means that is independent of and isolated from the actuation means.  
         [0040]    Although the description above contains many specificities, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the spinner may be attached to the handle base by different means; a coaxial, dual sheath design may be used; additional and/or alternative materials and joining methods may be used; the handle assembly components may have other configurations or dimensions; other means may be used to control the distance of travel of the thumb slide; the thumb pad may only partially overlap the handle base at part of its travel; a portion of the thumb slide may extend distal to the handle base; the thumb slide and handle base may fit together by different means; the sheath and/or drive wire may be removable from the handle assembly; the basket may have other configurations; the basket may be replaced with another type of tool, such as a grasping assembly or biopsy device; the device may be used without an endoscope; objects other than those mentioned or in different locations in the body may be retrieved, etc.  
         [0041]    Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.