Abstract:
An elongate medical instrument has an operative tip that is translatable and rotatable. A Translation and rotation are effectuated by the same elongate shifter member. The shifter member rotates together with a tubular catheter member about a longitudinal axis of the instrument. The simultaneous rotation enables the user to rotate a rotation control member on a handle assembly so that the operative tip rotates through the same angle as the control member. Where an electrical current is conducted to the operative tip for cauterization purposes, a rotary joint is provided with conductive capability.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to medical instrumentation useful in endoscopic surgery, particularly flexible endoscopic surgery. This invention relates more specifically to an endoscopic instrument wherein orientation of an operative tip is important in carrying out a surgical procedure. 
         [0002]    Much effort has been directed to developing medical instruments useful in endoscopic surgical procedures, having rotational and translational positioning capability. In the known instruments, a catheter or sheath is stationary relative to a handle assembly while a wire extending longitudinally through the sheath is provided with a rotational capability to facilitate orientation of an operative tip at the distal end of the wire with respect to a target tissue mass. Such an instrument is disclosed in U.S. Pat. No. 6,352,539 to Avellanet entitled “Surgical Instrument with Rotatable Shaft” (2002). 
         [0003]    U.S. Pat. No. 5,084,054 to Bencini et al. entitled “Surgical Gripping Instrument” (1992) discloses an instrument where there is only relative axial motion between a sheath or catheter and a wire inserted therethrough, while U.S. Pat. No. 6,235,026 to Smith entitled “Polypectomy Snare Instrument” (2001) discloses a surgical instrument where a shaft or wire is axially and rotationally movable. Pursuant to the disclosure of the latter patent, the sheath does not rotate with the shaft or wire. Instead, the sheath remains stationary while the shaft or wire is rotated. 
         [0004]    U.S. Pat. No. 5,788,710 to Bates et al. entitled “Calculus Removal” (1998) teaches a wire or rod inserted through a sheath of catheter and fixed to an actuator knob protruding from the proximal end of the instrument handle assembly. The knob is alternately pushed and pulled to effectuate an axial motion of the wire or rod relative to a sheath or catheter and is turned to effectuate a rotation of the wire or rod relative to the sheath of catheter. 
         [0005]    U.S. Pat. No. 5,066,295 to Kozak et al. entitled “Rotatable Surgical Snare” (1991) is directed to a quick-release connector that couples a sheath and wire assembly to a handle assembly. The wire rotates relative to the sheath. 
         [0006]    U.S. Pat. No. 3,955,578 to Chamness et al. entitled “Rotatable Surgical Snare” (1976) represents an early example of snare instrument with rotational capability. The snare is rotatably and axially moved by a wire that rotates and translates relative to a sheath or catheter through which the wire extends. 
         [0007]    U.S. Pat. No. 6,602,262 to Griego et al. entitled “Medical Device Having Linear to Rotation Control” (2003) discloses an instrument where a rotational movement of a snare is accomplished by converting an axial or longitudinal motion of a shifter element into a rotary motion. U.S. Patent Publication No. 2003/0050638 by Yachia et al. entitled “Surgical Instrument and Method of Using Same” (2003) describes a surgical instrument having a rotating operative tip where the rotation is induced by a shaft traversing a positioning tube that essentially remains stationary relative to the patient during the rotary ablation. 
         [0008]    U.S. Patent Publication No. 2003/0009276 by Bilitz entitled “Medical Retrieval Device with Independent Rotational Means” (2003) discloses an instrument with an operative tip in the form of a basket and with 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 and also permits rotation of the basket without requiring the sheath to rotate within the working channel of the endoscope. 
         [0009]    U.S. Pat. No. 5,984,920 to Steinbach entitled “Rotatable Sphincterotome/Pailltome and Method of Use” (1999) discloses a variation of the common operative configuration. In this variation, the wire is connected to the distal end of the catheter and bends or curves the distal end portion thereof when the wire is pulled in the proximal direction. Rotating the wire turns the distal end of the catheter slightly to one side of the other. 
         [0010]    U.S. Pat. No. 6,827,718 to Hutchins et al entitled “Method and Apparatus for Positioning and Maintaining the Position of Endoscopic Instruments” (2004) similarly discloses a rotatable coupling attaching a handle to a catheter allowing the handle to rotate relative to the proximal end of the catheter while engaging and rotating a proximal end of a cutting wire whereby a distal portion of the catheter rotates as a result of the rotation of the handle. A cutting wire extending through the catheter is attached at a distal end to the distal end of the catheter so that turning of the wire relative to the catheter at the proximal end induces a turning of the catheter at the distal end. 
         [0011]    U.S. Pat. No. 5,094,247 to Hernandez et al. entitled “Biopsy Forceps with Handle Having a Flexible Coupling” (1992) relates to a medical instrument where a handle is pivotable with respect to a secondary handle called a hub. The pivoting enables the operator to orient the handle at an angle with respect to that portion of the instrument which is inserted into a patient. The coupling includes a universal joint having a pair of orthogonal pivot axes. 
       OBJECTS OF THE INVENTION 
       [0012]    It is an object of the present invention to provide a medical instrument wherein an operative tip at the distal end of the instrument can rotate relative to a handle assembly at a proximal end of the instrument. 
         [0013]    Another object of the present invention is to provide such a medical that may be inserted through a working channel of a flexible endoscope so that the operative tip is axially and rotationally shiftable relative to the handle assembly. 
         [0014]    A further object of the present invention is to provide such an instrument that is easy to use. 
         [0015]    A more particular object of the present invention, and one that differentiates it from the inventions mentioned above, is to provide such an instrument that is simpler and less expensively manufactured, despite the complex requirements of rotational, and axial movement of the end effector relative to the endoscope. 
         [0016]    A more particular object of the present invention is to provide such an instrument where the operative tip is a cauterization loop or snare, or a hot biopsy forceps so that electrical current may be conducted along a shifter wire to the loop or snare from the handle assembly. 
         [0017]    Yet another more particular object of the invention is to provide such an instrument where the operative tip performs an operation other than a cautery operation, such as in a grasper, capture net, or stapler device, etc. 
         [0018]    These and other objects of the invention will be apparent from the drawings and descriptions herein. Although every object of the invention is believed to be achieved by at least one embodiment of the invention, there is not necessarily any single embodiment that achieves all of the objects of the invention. 
       SUMMARY OF THE INVENTION 
       [0019]    The present invention is directed to a medical instrument wherein a wire passing longitudinally through a sheath or catheter is axially shiftable relative to the sheath or catheter but where the sheath or catheter rotates with the wire to effectuate a rotation of the operative tip of the instrument. Axially shifting of the wire is effectuated via a ball- and socket universal joint that permits rotation of the sheath and wire relative to a handle assembly, while accommodating axial motion of the wire relative to the sheath or catheter, as well as relative to the handle assembly. 
         [0020]    A medical instrument comprises, in accordance with the present invention, a handle assembly including a main body, an axial position control member translatable relative to the main body, and a rotation control member rotatable relative to the main body. An elongate tubular member is connected at a proximal end to the handle assembly and an elongate shifter member (a rod, cable or tubular member) longitudinally traverses the tubular member. An operative tip is connected to the shifter member at a distal end thereof. The tubular member is operatively connected to the rotation control member for rotating about a longitudinal axis in response to manipulation of the rotation control member. The shifter member is also operatively connected to the rotation control member for rotating together with the tubular member about the longitudinal axis in response to manipulation of the rotation control member. The shifter member is operatively connected to the axial position control member for shifting axially relative to the tubular member in response to manipulation of the axial position control member. Thus, the shifter member (e.g., a wire or flexible rod) is rotationally entrained to the tubular member (e.g., sheath or catheter), but is axially movable relative to the tubular member. The shifter member is rotationally fixed to the tubular member, at the proximal ends thereof, but axially or longitudinally movable relative to the tubular member. 
         [0021]    Preferably, the shifter cable is made of a 1:1 torquable stainless steel (i.e., a rotation induced at the proximal end of the cable resulting in a rotational movement through substantially the same angle at the distal end of the cable). If the shifter member is a flexible solid rod made of NiTi (Nitinol), than the shifter member may be coated with gold or another metal that conducts well, in order to provide for the transmission of a cauterizing current. Alternatively, if the shifter member is a braided cable, then it may be made entirely of stainless steel strands constructed in a particular manner (produced on the market, and sold freely), or be made of strands of Nitinol, or another metal with 1:1 rotatable properties, and have a stainless steel wire woven into it for carrying an electrical current. If the shifter member is a tube, a wire of stainless steel or other conductive material may pass through the tube for carrying the cauterizing current. In any case, electrically conductive coating, strand, thread or wire extends along the shifter member, or makes up the entire shifter member from a proximal end to a distal end thereof. The coating, strand, thread or wire is connected to the operative tip for conveying electrical current thereof. The coating, strand, thread or wire is operatively connected to an electrical coupling element (terminal, contact, etc.) on the handle assembly. 
         [0022]    Where the instrument is an endoscopic instrument, the tubular member and the shifter member are flexible and dimensioned to fit through a working channel of a flexible endoscope assembly. 
         [0023]    Pursuant to another feature of the present invention, the rotation control member is disposed at a distal end of the handle assembly. The rotation control member may take the form of a sleeve or cylinder that is disposed like a nose on the distal end of the handle assembly. 
         [0024]    Preferably, the tubular member is fixed at a proximal end to the sleeve, while the shifter member longitudinally traverses the sleeve. The shifter member and the sleeve are rotationally entrained, exemplarily by one or more longitudinal splines fixed to the shifter member and extending into keyways or slots in the sleeve, for instance, in a transverse end wall of the sleeve. 
         [0025]    Pursuant to another feature of the present invention, the shifter member is connected to the axial position control member via a wire or rod fixed to the axial position control member, the shifter member being rotatably connected to the wire or rod via a rotary joint disposed inside the sleeve. The rotary joint may be a universal joint such as a ball and socket joint. 
         [0026]    The shifter member is preferably connected to the axial position control member via a stiff rod capable of transmitting an axial compressive force without bending or kinking. This rod extends through the handle assembly and the rotary joint (in which case the rod may include two segments coupled to one another via the rotary joint). The rod is generally connected to the shifter member at a point proximate to the rotational control member. 
         [0027]    It is to be noted that the operative tip may take virtually any form useful in medical procedures, where it is beneficial to controllably rotate the operative tip to accurately reorient it. For example, the operative may be a cauterization snare or a mechanism with pivoting jaws, such as a grasper, a biopsy forceps, or a stapler. In instruments such as graspers, biopsy forceps or the stapler, it is important that the jaws rotate. The jaws are connected to a clevis, which is connected to an outer sheath of the instrument. So the outer sheath must be rotatable by means a proximal rotator that is part of the handle and located at the distal end of the handle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]      FIG. 1  is a schematic side elevational view of an endoscopic surgical instrument in accordance with the present invention. 
           [0029]      FIG. 2  is a longitudinal cross-sectional view, on a larger scale, of a distal end portion of a handle assembly illustrated in  FIG. 1 . 
           [0030]      FIG. 3  is partially a perspective view and partially a schematic longitudinal cross-sectional view through a distal end of a stapling device rotatable about a longitudinal axis, in accordance with the present invention. 
           [0031]      FIG. 4  is a transverse cross-sectional view taken along plane IV-IV in  FIG. 3 . 
           [0032]      FIG. 5  is a schematic perspective view of a handle or actuator that is a part of the stapling device of  FIGS. 3 and 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    As illustrated in  FIG. 1 , a medical instrument comprises a handle assembly  12  including a main body  14 , an axial position control member  16  translatable relative to the main body, and a rotation control member  18  rotatable relative to the main body  14 . An elongate tubular member  20  such as a sheath or catheter is connected at a proximal end to handle assembly  12 , and an elongate shifter member  23  in the form of a flexible rod, cable or wire longitudinally traverses the tubular member. An operative tip  24  such as a cauterization loop or snare is connected to shifter member  23  at a distal end thereof. Shifter member  23  is a torque-transmitting rod, wire or cable that is connected at its proximal end, inside sheath  20  near handle assembly  12 , to a solid metal rod  22  capable of transmitting compressive forces without kinking. 
         [0034]    As further embodiment illustrated in  FIG. 1 , sheath  20  is operatively connected to rotation control member  18  for rotating about a longitudinal axis  26  in response to manipulation (turning) of the rotation control member. Shifter member or wire  23  is also operatively connected via rod  22  to rotation control member  18  for rotating together with tubular member  20  about longitudinal axis  26  in response to a turning of the rotation control member. Shifter member or wire  23  is operatively connected via rod  22  to axial position control member  16  for shifting axially relative to sheath  20  in response to manipulation of the axial position control member. Thus, the shifter member  23  (e.g., a wire or flexible rod) is rotationally entrained to sheath  20  (e.g., sheath or catheter), but is axially movable relative to sheath  20 . Shifter member  23  is rotationally fixed to sheath  20 , at the proximal end thereof, for rotation about longitudinal axis  26  in response to a turning of rotation control member  18  as indicated by a double-headed arrow  25 . Shifter member  23  is axially or longitudinally movable relative to sheath  20  in response to an axial translation of axial position control member  16  as indicated by an arrow  27 . 
         [0035]    Preferably, shifter member  23  is made of specially braided stainless steel, torquable in a 1:1 ratio or close to it. If shifter member  23  is made of NiTi, and to the extent that electrical current is to be conducted along the shifter member from handle assembly  12  to operative tip  24 , a conductive wire, strand or thread (not separately illustrated) may extend along the nitinol wire  22  for conducting the electrical current. The electrically conductive strand, thread or wire extends along shifter member  23  from a proximal end to a distal end thereof and is connected to operative tip  24  for conveying electrical current thereto. The strand, thread or wire is operatively connected to an electrical coupling element  28  (terminal, contact, etc.) on handle assembly  12 . 
         [0036]    Where the instrument is an endoscopic instrument, sheath  20  and shifter member  23  are flexible and dimensioned to fit through a working channel of a flexible endoscope assembly. 
         [0037]    Rotation control member  18  is disposed at a distal end of handle assembly  12 . As depicted in  FIG. 2 , rotation control member  18  specifically takes the form of a sleeve or cylinder that is disposed like a nose on the distal end of handle assembly  12 . Sheath  20  is fixed at a proximal end to rotation control sleeve  18 , while shifter member  23  longitudinally traverses the sleeve. Shifter member  23  and sleeve  18  are rotationally entrained, exemplarily by one or more longitudinal splines (not shown) fixed to wire  22  and extending into keyways or slots (not shown) in the sleeve, for instance, in a transverse end wall  30  of the sleeve. 
         [0038]    As further depicted in  FIG. 2 , shifter member  23  is connected to axial position control member  18  via rod  22  and another wire or rod  32  fixed to the axial position control member. Rod  22  (and therefore shifter member  23 ) is rotatably connected to wire or rod  32  via a rotary joint  34  disposed inside the sleeve. Rotary joint  34  particularly takes the form of a universal joint including a ball member  36  and a socket member  38 . Rods  22  and  32  may be considered two segments of a rod (not separately designated) that incorporates universal joint  34 . 
         [0039]    As illustrated in  FIGS. 3 and 4 , an endoscopic stapling device  40  comprises a pair of stapler jaws  42  and  44  having a loaded pre-firing position in which a staple  46  is disposed in a partially closed configuration between jaws  42  and  44 . Jaws  42  and  44  are pivotably secured to a clevis  48  that is in turn fixed to the distal end of a flexible inner tubular sheath or catheter  49 . A sleeve  50  for closing jaws  42  and  44  as well as staple  46  is slidably disposed about clevis  48  for advancing over jaws  42  and  44  after the jaws and a staple have been forced over organic tissues at a stapling site inside a patient. Sleeve  50  is fixed at a proximal end to a distal end of a flexible outer tubular sheath or catheter  52 . A turning torque for changing the angle of staple jaws  42  and  44  about a longitudinal axis  54  is applied via inner tubular sheath  49  and outer tubular sheath  52 . An extractor cable or flexible rod  56  is connected at a distal end to an extractor cap  58  (see  FIG. 4 ). A U-shaped closure bracket or backbone  59  is provided for locking staple  46  in a closed configuration in the patient&#39;s tissues. Closure bracket or backbone  59  is advanced over the open staple substantially simultaneously with the closing of jaws  42  and  44 . 
         [0040]    As depicted in  FIG. 5 , a handle  60  of the stapling device of  FIGS. 3 and 4  is connected to the proximal end of extractor cable or rod  56 , as well as to inner tubular sheath  49  and outer tubular sheath  52 . A thumb wheel  62  is provided on handle  60  for turning inner tubular sheath  49  and outer tubular sheath  52 . It is not necessary to turn extractor cable  56  because it is a revolution body without radial referencing. A spring-loaded push button  64  provided at the rear or proximal end of handle  60  is used for ejecting and closing the staple  46 . 
         [0041]    Outer tubular sheath  52  together with sleeve  50  comprises a shifter member that moves axially or longitudinally in a proximal direction to release jaws  42  and  44  and in a distal direction to close the jaws. Outer tubular sheath  52  is operatively connected inside handle  60  to a lever  66  that is actuated to alternately retract and advance the sheath or catheter  52  to open and close jaws  42  and  44 . Sheath  52  is also operatively connected, together with inner tubular sheath  49 , to thumb wheel  62  for enabling an operator to control the orientation of an operative tip or end effectuator, i.e., jaws  42  and  44 . Extractor cable  56  is operatively connected to push button  64  for pushing closure bracket or backbone  59  about staple  46  to thereby close the staple and lock it in a closed configuration. 
         [0042]    Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.