Patent Document

CROSS REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This is a continuation of U.S. patent application Ser. No. 13/923,590, filed on Jun. 21, 2013, issued as U.S. Pat. No. 8,672,959 on Mar. 18, 2014, which is a continuation of U.S. patent application Ser. No. 13/081,942, filed on Apr. 7, 2011, issued as U.S. Pat. No. 8,469,982 on Jun. 25, 2013, which is a continuation of U.S. patent application Ser. No. 11/234,714, filed on Sep. 23, 2005, issued as U.S. Pat. No. 8,002,782 on Aug. 23, 2011, which is a continuation of U.S. patent application Ser. No. 09/982,744, filed on Oct. 18, 2001, issued as U.S. Pat. No. 6,958,070 on Oct. 25, 2005, which is a continuation of U.S. patent application Ser. No. 09/644,991, filed on Aug. 24, 2000, now abandoned, which is a divisional of U.S. patent application Ser. No. 09/412,557 filed on Oct. 5, 1999, now abandoned, all of which are incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates, in general, to ultrasonic surgical clamping instruments and, more particularly, to a curved clamp arm tissue pad attachment for use with ultrasonic surgical instruments. 
       BACKGROUND OF THE INVENTION 
       [0003]    This application is related to the following copending patent applications: application Ser. No. 08/948,625 filed Oct. 10, 1997, issued as U.S. Pat. No. 6,068,647 on May 30, 2000; application Ser. No. 08/949,133 filed Oct. 10, 1997, issued as U.S. Pat. No. 5,947,984 on Sep. 7, 1999; application Ser. No. 09/106,686 filed Jun. 29, 1998, abandoned; application Ser. No. 09/337,077 filed Jun. 21, 1999, issued as U.S. Pat. No. 6,214,023 on Apr. 10, 2001; application Ser. No. 09/412,996 filed on Oct. 5, 1999, issued as U.S. Pat. No. 6,458,142 on Oct. 1, 2002; application Ser. No. 09/412,257 filed on Oct. 5, 1999, issued as U.S. Pat. No. 6,325,811; and application Ser. No. 09/413,225 filed on Oct. 5, 1999, abandoned, which are hereby incorporated herein by reference. 
         [0004]    Ultrasonic instruments, including both hollow core and solid core instruments, are used for the safe and effective treatment of many medical conditions. Ultrasonic instruments, and particularly solid core ultrasonic instruments, are advantageous because they may be used to cut and/or coagulate organic tissue using energy in the form of mechanical vibrations transmitted to a surgical end-effector at ultrasonic frequencies. Ultrasonic vibrations, when transmitted to organic tissue at suitable energy levels and using a suitable end-effector, may be used to cut, dissect, or cauterize tissue. Ultrasonic instruments utilizing solid core technology are particularly advantageous because of the amount of ultrasonic energy that may be transmitted from the ultrasonic transducer through the waveguide to the surgical end-effector. Such instruments are particularly suited for use in minimally invasive procedures, such as endoscopic or laparoscopic procedures, wherein the end-effector is passed through a trocar to reach the surgical site. 
         [0005]    Ultrasonic vibration is induced in the surgical end-effector by, for example, electrically exciting a transducer which may be constructed of one or more piezoelectric or magnetostrictive elements in the instrument hand piece. Vibrations generated by the transducer section are transmitted to the surgical end-effector via an ultrasonic waveguide extending from the transducer section to the surgical end-effector. 
         [0006]    Solid core ultrasonic surgical instruments may be divided into two types, single element end-effector devices and multiple-element end-effector. Single element end-effector devices include instruments such as scalpels, and ball coagulators, see, for example, U.S. Pat. No. 5,263,957. While such instruments as disclosed in U.S. Pat. No. 5,263,957 have been found eminently satisfactory, there are limitations with respect to their use, as well as the use of other ultrasonic surgical instruments. For example, single-element end-effector instruments have limited ability to apply blade-to-tissue pressure when the tissue is soft and loosely supported. Substantial pressure is necessary to effectively couple ultrasonic energy to the tissue. This inability to grasp the tissue results in a further inability to fully coapt tissue surfaces while applying ultrasonic energy, leading to less-than-desired hemostasis and tissue joining. 
         [0007]    The use of multiple-element end-effectors such as clamping coagulators include a mechanism to press tissue against an ultrasonic blade, that can overcome these deficiencies. A clamp mechanism disclosed as useful in an ultrasonic surgical device has been described in U.S. Pat. Nos. 3,636,943 and 3,862,630 to Balamuth. Generally, however, the Balamuth device, as disclosed in those patents, does not coagulate and cut sufficiently fast, and lacks versatility in that it cannot be used to cut/coagulate without the clamp because access to the blade is blocked by the clamp. 
         [0008]    Ultrasonic clamp coagulators such as, for example, those disclosed in U.S. Pat. Nos. 5,322,055 and 5,893,835 provide an improved ultrasonic surgical instrument for cutting/coagulating tissue, particularly loose and unsupported tissue, wherein the ultrasonic blade is employed in conjunction with a clamp for applying a compressive or biasing force to the tissue, whereby faster coagulation and cutting of the tissue, with less attenuation of blade motion, are achieved. However, clamp coagulating instruments such as described in U.S. Pat. Nos. 5,322,055 and 5,893,835 have been difficult to manufacture with curved end-effectors that can deliver sufficient energy to tissue, while maintaining the integrity of the ultrasonically active element. 
         [0009]    Improvements in technology of curved ultrasonic instruments such as described in U.S. patent application Ser. No. 09/106,686 previously incorporated herein by reference, have created needs for improvements in other aspects of curved clamp coagulators. For example, U.S. Pat. No. 5,873,873 describes an ultrasonic clamp coagulating instrument having an end-effector including a clamp arm comprising a tissue pad. In the configuration shown in U.S. Pat. No. 5,873,873 the clamp arm and tissue pad are straight. 
         [0010]    Attachment of the tissue pad to the clamp arm of an ultrasonic surgical instrument is important, in that failure of the attachment may cause the tissue pad to be lost during a surgical procedure, thereby complicating the surgery. Because of this, tissue pad attachments utilizing keyed slots on one element and an associated key on an attachable element have been developed, such as, for example, pads described in U.S. patent application Ser. No. 09/337,077 previously incorporated herein by reference. U.S. patent application Ser. No. 09/337,077 describes, in one embodiment, a tissue pad having a T-shaped flange insertable into a clamp arm having a T-shaped slot. 
         [0011]    Although attachments such as the T-shaped system described in U.S. Patent Application No. END-506 filed Jun. 21, 1999 are effective, difficulty arises when trying to bend or curve the end-effector. Slots such as disclosed above cannot be easily molded or otherwise manufactured with complex curves. Thus, it would be advantageous to provide a simple and cost effective way to attach tissue pads to clamp arms on curved ultrasonic clamp instruments. It would further be advantageous to provide ultrasonic clamp coagulating instruments with curved end-effectors that were simple to manufacture. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention meets the above stated needs for an improved curved end-effector. A curved clamp arm for use with an ultrasonic surgical instrument is described. The curved clamp arm includes a proximal end and a distal end, with a top surface extending from the proximal end to the distal end of the curved clamp arm. The top surface comprises at least one hole. The clamp arm includes a bottom surface opposite the top surface, with the bottom surface extending from the proximal end to the distal end of the clamp arm. The bottom surface includes at least one engaging surface, where the hole in the top surface extends from the top surface to the engaging surface of the clamp arm. One embodiment of the curved clamp arm includes a plurality of the holes in the top surface, and a plurality of the engaging surfaces in the bottom surface, where each hole in the top surface extends through the curved clamp arm, terminating at a corresponding engaging surface on the bottom surface. The plurality of holes may also be staggered laterally from the proximal end of the clamp arm to the distal end of the clamp arm. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which: 
           [0014]      FIG. 1  illustrates an ultrasonic surgical system including an elevational view of an ultrasonic generator, a sectioned plan view of an ultrasonic transducer, and a partially sectioned plan view of a clamp coagulator in accordance with the present invention; 
           [0015]      FIG. 2A  is an exploded perspective view of a portion of a clamp coagulator in accordance with the present invention; 
           [0016]      FIG. 2B  is an exploded perspective view of a portion of a clamp coagulator in accordance with the present invention; 
           [0017]      FIG. 3  is a partially sectioned plan view of a clamp coagulator in accordance with the present invention with the clamp arm assembly shown in an open position; 
           [0018]      FIG. 4  is a partially sectioned plan view of a clamp coagulator in accordance with the present invention with the clamp arm assembly shown in a closed position; 
           [0019]      FIG. 5  is a side view of a collar cap of the clamp coagulator; 
           [0020]      FIG. 6  is a front view of a collar cap of the clamp coagulator; 
           [0021]      FIG. 7  is a side view of a force limiting spring of the clamp coagulator; 
           [0022]      FIG. 8  is a front view of a force limiting spring of the clamp coagulator; 
           [0023]      FIG. 9  is a side view of a washer of the clamp coagulator; 
           [0024]      FIG. 10  is a front view of a washer of the clamp coagulator; 
           [0025]      FIG. 11  is a side view of a tubular collar of the clamp coagulator; 
           [0026]      FIG. 12  is a rear view of a tubular collar of the clamp coagulator; 
           [0027]      FIG. 13  is a front view of a tubular collar of the clamp coagulator; 
           [0028]      FIG. 14  is a side view of an inner knob of the clamp coagulator; 
           [0029]      FIG. 15  is a front view of an inner knob of the clamp coagulator; 
           [0030]      FIG. 16  is a bottom view of an inner knob of the clamp coagulator; 
           [0031]      FIG. 17  is a rear view of an outer knob of the clamp coagulator; 
           [0032]      FIG. 18  is a top view of an outer knob of the clamp coagulator; 
           [0033]      FIG. 19  is a top view of a yoke of the clamp coagulator; 
           [0034]      FIG. 20  is a side view of a yoke of the clamp coagulator; 
           [0035]      FIG. 21  is a front view of a yoke of the clamp coagulator; 
           [0036]      FIG. 22  is a perspective view of a yoke of the clamp coagulator; 
           [0037]      FIG. 23  is a perspective view of an end-effector of the clamp coagulator; 
           [0038]      FIG. 24  is a top perspective view of a clamp arm of the camp coagulator; 
           [0039]      FIG. 25  is a top view of an end-effector of the clamp coagulator; 
           [0040]      FIG. 26  is a side view of an end-effector of the clamp coagulator with the clamp arm open; 
           [0041]      FIG. 27  is a top view of a tissue pad of the clamp coagulator; 
           [0042]      FIG. 28  is a side view of a tissue pad of the clamp coagulator; 
           [0043]      FIG. 29  is a front view of a tissue pad of the clamp coagulator; 
           [0044]      FIG. 30  is a perspective view of a tissue pad of the clamp coagulator; 
           [0045]      FIG. 31  is a bottom perspective view of a clamp arm of the camp coagulator; 
           [0046]      FIG. 32  is a first cross-sectional view of the clamp arm illustrated in  FIG. 31 ; and 
           [0047]      FIG. 33  is a second cross-sectional view of the clamp arm illustrated in  FIG. 31 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0048]    The present invention will be described in combination with ultrasonic instruments as described herein. Such description is exemplary only, and is not intended to limit the scope and applications of the invention. For example, the invention is useful in combination with a multitude of ultrasonic instruments including those described in, for example, U.S. Pat. Nos. 5,938,633; 5,935,144; 5,944,737; 5,322,055, 5,630,420; and 5,449,370. 
         [0049]      FIG. 1  illustrates a plan view of an ultrasonic system  10  comprising an ultrasonic signal generator  15  with a sectioned plan view of a sandwich type ultrasonic transducer  82 , hand piece housing  20 , and clamp coagulator  120  in accordance with the present invention. Clamp coagulator  120  may be used for open or laparoscopic surgery. The ultrasonic transducer  82 , which is known as a “Langevin stack”, generally includes a transduction portion  90 , a first resonator or end-bell  92 , and a second resonator or fore-bell  94 , and ancillary components. The ultrasonic transducer  82  is preferably an integral number of one-half system wavelengths (nλ/2) in length as will be described in more detail later. An acoustic assembly  80  includes the ultrasonic transducer  82 , mount  36 , velocity transformer  64  and surface  95 . 
         [0050]    The distal end of end-bell  92  is connected to the proximal end of transduction portion  90 , and the proximal end of fore-bell  94  is connected to the distal end of transduction portion  90 . Fore-bell  94  and end-bell  92  have a length determined by a number of variables, including the thickness of the transduction portion  90 , the density and modulus of elasticity of the material used to manufacture end-bell  92  and fore-bell  94 , and the resonant frequency of the ultrasonic transducer  82 . The fore-bell  94  may be tapered inwardly from its proximal end to its distal end to amplify the ultrasonic vibration amplitude as velocity transformer  64 , or alternately may have no amplification. 
         [0051]    The piezoelectric elements  100  may be fabricated from any suitable material, such as, for example, lead zirconate-titanate, lead meta-niobate, lead titanate, or other piezoelectric crystal material. Each of the positive electrodes  96 , negative electrodes  98 , and piezoelectric elements  100  has a bore extending through the center. The positive and negative electrodes  96  and  98  are electrically coupled to wires  102  and  104 , respectively. Wires  102  and  104  are encased within cable  25  and electrically connectable to ultrasonic signal generator  15  of ultrasonic system  10 . 
         [0052]    Ultrasonic transducer  82  of the acoustic assembly  80  converts the electrical signal from ultrasonic signal generator  15  into mechanical energy that results in primarily longitudinal vibratory motion of the ultrasonic transducer  82  and an end-effector  180  at ultrasonic frequencies. When the acoustic assembly  80  is energized, a vibratory motion standing wave is generated through the acoustic assembly  80 . The amplitude of the vibratory motion at any point along the acoustic assembly  80  depends on the location along the acoustic assembly  80  at which the vibratory motion is measured. A minimum or zero crossing in the vibratory motion standing wave is generally referred to as a node (i.e., where motion is usually minimal), and an absolute value maximum or peak in the standing wave is generally referred to as an anti-node. The distance between an anti-node and its nearest node is one-quarter wavelength (λ/4). 
         [0053]    Wires  102  and  104  transmit the electrical signal from the ultrasonic signal generator  15  to positive electrodes  96  and negative electrodes  98 . A suitable generator is available as model number GEN01, from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. The piezoelectric elements  100  are energized by an electrical signal supplied from the ultrasonic signal generator  15  in response to a foot switch  118  to produce an acoustic standing wave in the acoustic assembly  80 . The electrical signal causes disturbances in the piezoelectric elements  100  in the form of repeated small displacements resulting in large compression forces within the material. The repeated small displacements cause the piezoelectric elements  100  to expand and contract in a continuous manner along the axis of the voltage gradient, producing longitudinal waves of ultrasonic energy. The ultrasonic energy is transmitted through the acoustic assembly  80  to the end-effector  180 . 
         [0054]    In order for the acoustic assembly  80  to deliver energy to end-effector  180 , all components of acoustic assembly  80  must be acoustically coupled to the ultrasonically active portions of clamp coagulator  120 . The distal end of the ultrasonic transducer  82  may be acoustically coupled at surface  95  to the proximal end of an ultrasonic waveguide  179  by a threaded connection such as stud  50 . 
         [0055]    The components of the acoustic assembly  80  are preferably acoustically tuned such that the length of any assembly is an integral number of one-half wavelengths (nλ/2), where the wavelength λ is the wavelength of a pre-selected or operating longitudinal vibration drive frequency fd of the acoustic assembly  80 , and where n is any positive integer. It is also contemplated that the acoustic assembly  80  may incorporate any suitable arrangement of acoustic elements. 
         [0056]    Referring now to  FIGS. 2A and 2B , an exploded perspective view of the clamp coagulator  120  of the surgical system  10  in accordance with the present invention is illustrated. The clamp coagulator  120  is preferably attached to and removed from the acoustic assembly  80  as a unit. The proximal end of the clamp coagulator  120  preferably acoustically couples to the distal surface  95  of the acoustic assembly  80  as shown in  FIG. 1 . It will be recognized that the clamp coagulator  120  may be coupled to the acoustic assembly  80  by any suitable means. 
         [0057]    The clamp coagulator  120  preferably includes an instrument housing  130 , and an elongated member  150 . The elongated member  150  can be selectively rotated with respect to the instrument housing  130  as further described below. The instrument housing  130  includes a pivoting handle portion  136 , and a fixed handle  132 A and  132 B coupled to a left shroud  134  and a right shroud  138  respectively. 
         [0058]    The right shroud  138  is adapted to snap fit on the left shroud  134 . The right shroud  138  is preferably coupled to the left shroud  134  by a plurality of inwardly facing prongs  70  formed on the right shroud  138 . The plurality of prongs  70  are arranged for engagement in corresponding holes or apertures  140 , which are formed in the left shroud  134 . When the left shroud  134  is attached to the right shroud  138 , a cavity is formed therebetween to accommodate various components, such as an inner or indexing mechanism  255  as further described below. 
         [0059]    The left shroud  134 , and the right shroud  138  of the clamp coagulator  120  are preferably fabricated from polycarbonate. It is contemplated that these components may be made from any suitable material without departing from the spirit and scope of the invention. 
         [0060]    Indexing mechanism  255  is disposed in the cavity of the instrument housing  130 . The indexing mechanism  255  is preferably coupled or attached on inner tube  170  to translate movement of the handle portion  136  to linear motion of the inner tube  170  to open and close the clamp arm assembly  300 . When the pivoting handle portion  136  is moved toward the fixed handle portion  130 , the indexing mechanism  255  slides the inner tube  170  rearwardly to pivot the clamp arm assembly  300  into a closed position. The movement of the pivoting handle portion  136  in the opposite direction slides the indexing mechanism  255  to displace the inner tube  170  in the opposite direction, i.e., forwardly, and hence pivot the clamp arm assembly  300  into its open position. 
         [0061]    The indexing mechanism  255  also provides a ratcheting mechanism to allow the elongated member  150  to rotate about its longitudinal axis relative to instrument housing  130 . The rotation of the elongated member  150  enables the clamp arm assembly  300  to be turned to a selected or desired angular position. The indexing mechanism  255  preferably includes a tubular collar  260  and yoke  280 . 
         [0062]    The tubular collar  260  of the indexing mechanism  255  is preferably snapped onto the proximal end of the inner tube  170  and keyed into opposing openings  168 . The tubular collar  260  is preferably fabricated from polyetherimide. It is contemplated that the tubular collar  260  may be constructed from any suitable material. 
         [0063]    Tubular collar  260  is shown in greater detail in  FIGS. 11 through 13 . The tubular collar  260  preferably includes an enlarged section  262 , and a bore  266  extending therethrough. The enlarged section  262  preferably includes a ring  272  formed around the periphery of the tubular collar  260  to form groove  268 . The groove  268  has a plurality of detents or teeth  269  for retaining the elongated member  150  in different rotational positions as the elongated member  150  is rotated about its longitudinal axis. Preferably, the groove  268  has twelve ratchet teeth to allow the elongated portion to be rotated in twelve equal angular increments of approximately 30 degrees. It is contemplated that the tubular collar  260  may have any number of teeth-like members. It will be recognized that the teeth-like members may be disposed on any suitable part of the tubular collar  260  without departing from the scope and spirit of the present invention. 
         [0064]    Referring back now to  FIGS. 2 through 4 , the pivoting handle portion  136  includes a thumb loop  142 , a first hole  124  and a second hole  126 . A pivot pin  153  is disposed through first hole  124  of handle portion  136  to pivot as shown by arrow  121  in  FIG. 3 . As thumb loop  142  of pivoting handle portion  136  is moved in the direction of arrow  121 , away from instrument housing  130 , a link  128  applies a forward force to yoke  280 , causing yoke  280  to move forward. Link  128  is connected to pivoting handle portion  136  by a pin  129 , and link  128  is connected to base  284  by a pin  127 . 
         [0065]    Referring back now to  FIG. 2 , yoke  280  generally includes a holding or supporting member  282  and a base  284 . The supporting member  282  is preferably semi-circular and has a pair of opposing pawls  286  that extend inwardly to engage with the teeth  269  of the tubular collar  260 . It is contemplated that the pawls  286  may be disposed on any suitable part of the yoke  280  for engagement with the teeth  269  of the tubular collar  260  without departing from the spirit and scope of the invention. It will also be recognized that the yoke  280  may have any number of ratchet arms. 
         [0066]    Yoke  280  is shown in greater detail in  FIGS. 19 through 22 . The pivoting handle portion  136  preferably is partially disposed in a slot  147  of the base  284  of the yoke  280 . The base  284  also includes a base opening  287 , an actuator travel stop  290 , and a base pin-hole  288 . The pivot pin  153  is disposed through the base opening  287 . Yoke  280  pawls  286  transfer opening force to inner tube  170  through tubular collar  260 , resulting in the opening of clamp arm assembly  300 . 
         [0067]    The yoke  280  of the clamp coagulator  120  is preferably fabricated from polycarbonate. The yoke  280  may also be made from a variety of materials including other plastics, such as ABS, NYLON, or polyetherimide. It is contemplated that the yoke  280  may be constructed from any suitable material without departing from the spirit and scope of the invention. 
         [0068]    As illustrated in  FIGS. 3 and 4 , yoke  280  also transfers a closing force to clamp arm assembly  300  as pivoting handle portion  136  is moved toward instrument housing  130 . Actuator travel stop  290  contacts pivot pin  153  at the bottom of the stroke of pivoting handle portion  136 , stopping any further movement, or overtravel, of pivoting handle portion  136 . Pawls  286  of yoke  280  transfer force to tubular collar  260  through a washer  151 , a force limiting spring  155 , and collar cap  152 . Collar cap  152  is rigidly attached to tubular collar  260  after washer  151  and force limiting spring  155  have been assembled onto tubular collar  260  proximal to enlarged section  262 . Collar cap  152  is illustrated in greater detail in  FIGS. 5 and 6 . Force limiting spring  155  is illustrated in greater detail in  FIGS. 7 and 8 , and washer  151  is illustrated in greater detail in  FIGS. 9 and 10 . Thickness of washer  151  may be adjusted during design or manufacturing of clamp coagulator  120  to alter the pre-load of force limiting spring  155 . Collar cap  152  is attached to tubular collar  260  by ultrasonic welding, but may alternately be press fit, snap fit or attached with an adhesive. 
         [0069]    Referring to  FIGS. 5 through 10 , tubular collar  260 , a washer  151 , force limiting spring  155 , and collar cap  152  provide a force limiting feature to clamp arm assembly  300 . As pivoting handle portion  136  is moved toward instrument housing  130 , clamp arm assembly  300  is rotated toward ultrasonic blade  88 . In order to provide both ultrasonic cutting, and hemostasis, it is desirable to limit the maximum force of clamp arm assembly  300  to 0.5 to 3.0 Lbs. 
         [0070]      FIGS. 5 and 6  illustrate collar cap  152  including a spring surface  158 .  FIGS. 7 and 8  illustrate force limiting spring  155  including a cap surface  156 , a washer surface  157 , and a plurality of spring elements  159 . Force limiting spring  155  is described in the art as a wave spring, due to the shape of spring elements  159 . It is advantageous to use a wave spring for force limiting spring  155  because it provides a high spring rate in a small physical size well suited to an ultrasonic surgical instrument application where a central area is open for ultrasonic waveguide  179 . Force limiting spring  155  is biased between spring surface  158  of collar cap  152  and spring face  165  of washer  151 . Washer  151  includes a pawl face  167  ( FIGS. 9 and 10 ) that contacts pawls  286  of yoke  280  after assembly of clamp coagulator  120  (see  FIGS. 2 through 4 ). 
         [0071]    Referring now to  FIG. 2  and  FIGS. 14 through 18 , a rotational knob  190  is mounted on the elongated member  150  to turn the elongated member  150  so that the tubular collar  260  rotates with respect to the yoke  280 . The rotational knob  190  may be fabricated from polycarbonate. The rotational knob  190  may also be made from a variety of materials including other plastics, such as a polyetherimide, nylon, or any other suitable material. 
         [0072]    The rotational knob  190  preferably has an enlarged section or outer knob  192 , an inner knob  194 , and an axial bore  196  extending therethrough Inner knob  194  includes keys  191  that attach cooperatively to keyways  189  of outer knob  192 . The outer knob  192  includes alternating longitudinal ridges  197  and grooves  198  that facilitate the orientation of the rotational knob  190  and the elongated member  150  by a surgeon. The axial bore  196  of the rotational knob  190  is configured to snugly fit over the proximal end of the elongated member  150 . 
         [0073]    The inner knob  194  extends through an opening  139  in the distal end of the instrument housing  130 . Inner knob  194  includes a channel  193  to rotatably attach inner knob  194  into opening  139 . The inner knob  194  of the rotational knob  190  has a pair of opposing holes  199 . The opposing holes  199  are aligned as part of a passageway  195  that extends through the elongated member  150 , as will be described later. 
         [0074]    A coupling member, such as, for example, pin  163 , may be positioned through opposing holes  199  of the passageway  195 . The pin  163  may be held in the passageway  195  of the elongated member  150  by any suitable means, such as, for example, trapped between ribs in housing  130 , or a silicone or cyanoacrylate adhesive. The pin  163  allows rotational torque to be applied to the elongated member  150  from the rotational knob  190  in order to rotate the elongated member  150 . 
         [0075]    When the rotational knob  190  is rotated, the teeth  269  of the tubular collar  260  engage and ride up slightly on the corresponding pawls  286  of the yoke  280 . As the pawls  286  ride up on the teeth  269 , the supporting member  282  of the yoke  280  deflects outwardly to allow pawls  286  to slip or pass over the teeth  269  of the tubular collar  260 . 
         [0076]    In one embodiment, the teeth  269  of the tubular collar  260  are configured as ramps or wedges, and the pawls  286  of the yoke  280  are configured as posts. The teeth  269  of the tubular collar  260  and the pawls  286  of the yoke  280  may be reversed so that the teeth  269  of the tubular collar  260  are posts, and the pawls  286  of the yoke  280  are ramps or wedges. It is contemplated that the teeth  269  may be integrally formed or coupled directly to the periphery of the elongated member  150 . It will also be recognized that the teeth  269  and the pawls  286  may be cooperating projections, wedges, cam surfaces, ratchet-like teeth, serrations, wedges, flanges, or the like which cooperate to allow the elongated member  150  to be indexed at selective angular positions, without departing from the spirit and scope of the invention. 
         [0077]    As illustrated in  FIG. 2 , the elongated member  150  of the clamp coagulator  120  extends from the instrument housing  130 . As shown in  FIGS. 2B through 4 , the elongated member  150  preferably includes an outer member or outer tube  160 , an inner member or inner tube  170 , and a transmission component or ultrasonic waveguide  179 . 
         [0078]    The outer tube  160  of the elongated member  150  preferably includes a hub  162 , a tubular member  164 , and a longitudinal opening or aperture  166  extending therethrough. The outer tube  160  preferably has a substantially circular cross-section and may be fabricated from stainless steel. It will be recognized that the outer tube  160  may be constructed from any suitable material and may have any suitable cross-sectional shape. 
         [0079]    The hub  162  of the outer tube  160  preferably has a larger diameter than the tubular member  164  does. The hub  162  has a pair of outer tube holes  161  to receive pin  163  to allow the hub  162  to be coupled to rotational knob  190 . As a result, the outer tube  160  will rotate when the rotational knob  190  is turned or rotated. 
         [0080]    The hub  162  of the outer tube  160  also includes wrench flats  169  on opposite sides of the hub  162 . The wrench flats  169  are preferably formed near the distal end of the hub  162 . The wrench flats  169  allow torque to be applied by a torque wrench to the hub  162  to tighten the ultrasonic waveguide  179  to the stud  50  of the acoustic assembly  80 . For example, U.S. Pat. Nos. 5,059,210 and 5,057,119, which are hereby incorporated herein by reference, disclose torque wrenches for attaching and detaching a transmission component to a mounting device of a hand piece assembly. 
         [0081]    Located at the distal end of the tubular member  164  of the outer tube  160  is an end-effector  180  for performing various tasks, such as, for example, grasping tissue, cutting tissue and the like. It is contemplated that the end-effector  180  may be formed in any suitable configuration. 
         [0082]    End-effector  180  and its components are shown in greater detail in  FIGS. 23 through 33 . The end-effector  180  generally includes a non-vibrating clamp arm assembly  300  to, for example, grip tissue or compress tissue against the ultrasonic blade  88 . The end-effector  180  is illustrated in  FIGS. 23 and 26  in a clamp open position, and clamp arm assembly  300  is preferably pivotally attached to the distal end of the outer tube  160 . Ultrasonic vibrations are transmitted along the ultrasonic waveguide  179  in a longitudinal direction to vibrate the ultrasonic blade  88 . 
         [0083]    Looking first to  FIGS. 23 through 26 , the clamp arm assembly  300  preferably includes a clamp arm  202 , a jaw aperture  204 , a first post  206 A and a second post  206 B, and a tissue pad  208 . The clamp arm  202  is pivotally mounted about pivot pins  207 A and  207 B to rotate in the direction of arrow  122  in  FIG. 3  when thumb loop  142  is moved in the direction indicated by arrow  121  in  FIG. 3 . By advancing the pivoting handle portion  136  toward the instrument housing  130 , the clamp arm  202  is pivoted about the pivot pin  207  into a closed position. Retracting the pivoting handle portion  136  away from the instrument housing  130  pivots the clamp arm  202  into an open position. 
         [0084]    The clamp arm  202  has tissue pad  208  attached thereto for squeezing tissue between the ultrasonic blade  88  and clamp arm assembly  300 . The tissue pad  208  is preferably formed of a polymeric or other compliant material and engages the ultrasonic blade  88  when the clamp arm  202  is in its closed position. Preferably, the tissue pad  208  is formed of a material having a low coefficient of friction but which has substantial rigidity to provide tissue-grasping capability, such as, for example, TEFLON, a trademark name of E.I. Du Pont de Nemours and Company for the polymer polytetraflouroethylene (PTFE). The tissue pad  208  may be mounted to the clamp arm  202  by an adhesive, or preferably by a mechanical fastening arrangement as will be described below. 
         [0085]    As illustrated in  FIGS. 23 ,  26  and  28 , serrations  210  are formed in the clamping surfaces of the tissue pad  208  and extend perpendicular to the axis of the ultrasonic blade  88  to allow tissue to be grasped, manipulated, coagulated and cut without slipping between the clamp arm  202  and the ultrasonic blade  88 . 
         [0086]    Tissue pad  208  is illustrated in greater detail in  FIGS. 27 through 29 . Tissue pad  208  includes a T-shaped protrusion  212 , a left protrusion surface  214 , a right protrusion surface  216 , a top surface  218 , and a bottom surface  219 . Bottom surface  219  includes the serrations  210  previously described. Tissue pad  208  also includes a beveled front end  209  to ease insertion during assembly as will be described below. 
         [0087]    Referring now to  FIG. 26 , the distal end of the tubular member  174  of the inner tube  170  preferably includes a finger or flange  171  that extends therefrom. The flange  171  has openings  173 A and  173 B (opening  173 B not shown) to receive the post  206  of the clamp arm  202 . When the inner tube  170  of the elongated member  150  is moved axially, the flange  171  moves forwardly or rearwardly while engaging the post  206  of the clamp arm assembly  300  to open and close the clamp arm  202 . 
         [0088]    Referring now to  FIGS. 24 ,  25 , and  31  through  33 , the clamp arm  202  of end-effector  180  is shown in greater detail. Clamp arm  202  includes an arm top  228  and an arm bottom  230 , as well as a straight portion  235  and a curved portion  236 . Straight portion  235  includes a straight T-slot  226 . Curved portion  236  includes a first top hole  231 , a second top hole  232 , a third top hole  233 , a fourth top hole  234 , a first bottom cut-out  241 , a second bottom cut-out  242 , a third bottom cut-out  243 , a forth bottom cut-out  244 , a first ledge or engaging surface  221 , a second engaging surface  222 , a third engaging surface  223 , a fourth engaging surface  224 , and a fifth engaging surface  225 . 
         [0089]    Top hole  231  extends from arm top  228  through clamp arm  202  to second engaging surface  222 . Top hole  232  extends from arm top  228  through clamp arm  202  to third engaging surface  223 . Top hole  233  extends from arm top  228  through clamp arm  202  to fourth engaging surface  224 . Top hole  234  extends from arm top  228  through clamp arm  202  to fifth engaging surface  225 . 
         [0090]    Holes  231  through  234  are staggered laterally from proximal top hole  232  to distal top hole  234 . Likewise, engaging surfaces  221  through  225  are staggered laterally from proximal engaging surface  221  to distal engaging surface  225 . Hole  231  is arranged to terminate at engaging surface  222 , hole  232  is arranged to terminate at engaging surface  223 , hole  233  is arranged to terminate at engaging surface  224 , and hole  234  is arranged to terminate at engaging surface  225 . The arrangement of holes  231  through  234  and engaging surfaces  221  through  225  enables clamp arm  202  to include both the straight portion  235  and the curved portion  236 , while being moldable from a process such as, for example, metal injection molding (MIM). Clamp arm  202  may be made out of stainless steel or other suitable metal utilizing the MIM process. 
         [0091]    The arrangement of holes  231  through  234  and engaging surfaces  221  through  225  also enables the insertion of tissue pad  208 , that may be manufactured straight, into a curved clamp arm  202 . Beveled front end  209  of tissue pad  208  (see  FIG. 28 ) facilitates insertion of tissue pad  208  T-shaped protrusion  212  into clamp arm  202  straight T-slot  226  and through curved portion  236 . 
         [0092]    Referring to  FIGS. 30 and 31 , tissue pad  208  T-shaped protrusion  212  is insertable into clamp arm  202  straight T-slot  226 . Clamp arm  202  is designed such that tissue pad  208  may be manufactured as a straight component by, for example, injection molding, machining, or extrusion. As clamp arm  202  is inserted into straight T-slot  226  and moved progressively through curved portion  236 , beveled front edge  209  facilitates bending of tissue pad  208  to conform to the curvature of clamp arm  202 . The arrangement of holes  231  through  234  and engaging surfaces  211  through  225  enables clamp arm  202  to bend and hold tissue pad  208 . 
         [0093]      FIGS. 32 and 33  illustrate how clamp arm  202  holds tissue pad  208  in place while maintaining a bend in tissue pad  208  that conforms to curved portion  236  of clamp arm  202 . As illustrated in  FIG. 32 , third engaging surface  223  contacts right protrusion surface  216  providing a contact edge  238 , while left protrusion surface  214  is unsupported at this position. At a distal location, illustrated in  FIG. 33 , fourth engaging surface  224  contacts left protrusion surface  214  providing a contact edge  239 , while right protrusion surface  216  is unsupported at this location. 
         [0094]    Referring back now to  FIG. 2  again, the inner tube  170  of the elongated member  150  fits snugly within the opening  166  of the outer tube  160 . The inner tube  170  preferably includes an inner hub  172 , a tubular member  174 , a circumferential groove  176 , a pair of opposing openings  178 , a pair of opposing openings  178 , and a longitudinal opening or aperture  175  extending therethrough. The inner tube  170  preferably has a substantially circular cross-section, and may be fabricated from stainless steel. It will be recognized that the inner tube  170  may be constructed from any suitable material and may be any suitable shape. 
         [0095]    The inner hub  172  of the inner tube  170  preferably has a larger diameter than the tubular member  174  does. The pair of opposing openings  178  of the inner hub  172  allow the inner hub  172  to receive the pin  163  to allow the inner tube  170  and the ultrasonic waveguide  179  to transfer torque for attaching ultrasonic waveguide  179  to stud  50  as previously described. An O-ring  220  is preferably disposed in the circumferential groove  176  of the inner hub  172 . 
         [0096]    The ultrasonic waveguide  179  of the elongated member  150  extends through aperture  175  of the inner tube  170 . The ultrasonic waveguide  179  is preferably substantially semi-flexible. It will be recognized that the ultrasonic waveguide  179  may be substantially rigid or may be a flexible wire. 
         [0097]    The ultrasonic waveguide  179  may, for example, have a length substantially equal to an integral number of one-half system wavelengths (nX/ 2 ). The ultrasonic waveguide  179  may be preferably fabricated from a solid core shaft constructed out of material which propagates ultrasonic energy efficiently, such as titanium alloy (i.e., Ti-6Al-4V) or an aluminum alloy. It is contemplated that the ultrasonic waveguide  179  may be fabricated from any other suitable material. The ultrasonic waveguide  179  may also amplify the mechanical vibrations transmitted to the ultrasonic blade  88  as is well known in the art. 
         [0098]    As illustrated in  FIG. 2 , the ultrasonic waveguide  179  may include one or more stabilizing silicone rings or damping sheaths  110  (one being shown) positioned at various locations around the periphery of the ultrasonic waveguide  179 . The damping sheaths  110  dampen undesirable vibration and isolate the ultrasonic energy from the inner tube  170  assuring the flow of ultrasonic energy in a longitudinal direction to the distal end of the ultrasonic blade  88  with maximum efficiency. The damping sheaths  110  may be secured to the ultrasonic waveguide  179  by an interference fit such as, for example, a damping sheath described in U.S. patent application Ser. No. 08/808,652 hereby incorporated herein by reference. 
         [0099]    Referring again to  FIG. 2 , the ultrasonic waveguide  179  generally has a first section  182 , a second section  184 , and a third section  186 . The first section  182  of the ultrasonic waveguide  179  extends distally from the proximal end of the ultrasonic waveguide  179 . The first section  182  has a substantially continuous cross-section dimension. 
         [0100]    The first section  182  preferably has at least one radial waveguide hole  188  extending therethrough. The waveguide hole  188  extends substantially perpendicular to the axis of the ultrasonic waveguide  179 . The waveguide hole  188  is preferably positioned at a node but may be positioned at any other suitable point along the ultrasonic waveguide  179 . It will be recognized that the waveguide hole  188  may have any suitable depth and may be any suitable shape. 
         [0101]    The waveguide hole  188  of the first section  182  is aligned with the opposing openings  178  of the hub  172  and outer tube holes  161  of hub  162  to receive the pin  163 . The pin  163  allows rotational torque to be applied to the ultrasonic waveguide  179  from the rotational knob  190  in order to rotate the elongated member  150 . Passageway  195  of elongated member  150  includes opposing openings  178 , outer tube holes  161 , waveguide hole  188 , and opposing holes  199 . 
         [0102]    The second section  184  of the ultrasonic waveguide  179  extends distally from the first section  182 . The second section  184  has a substantially continuous cross-section dimension. The diameter of the second section  184  is smaller than the diameter of the first section  182 . As ultrasonic energy passes from the first section  182  of the ultrasonic waveguide  179  into the second section  184 , the narrowing of the second section  184  will result in an increased amplitude of the ultrasonic energy passing therethrough. 
         [0103]    The third section  186  extends distally from the distal end of the second section  184 . The third section  186  has a substantially continuous cross-section dimension. The third section  186  may also include small diameter changes along its length. The third section preferably includes a seal  187  formed around the outer periphery of the third section  186 . As ultrasonic energy passes from the second section  184  of the ultrasonic waveguide  179  into the third section  186 , the narrowing of the third section  186  will result in an increased amplitude of the ultrasonic energy passing therethrough. 
         [0104]    The third section  186  may have a plurality of grooves or notches (not shown) formed in its outer circumference. The grooves may be located at nodes of the ultrasonic waveguide  179  or any other suitable point along the ultrasonic waveguide  179  to act as alignment indicators for the installation of a damping sheath  110  during manufacturing. 
         [0105]    Still referring to  FIG. 2 , damping sheath  110  of the surgical instrument  150  surrounds at least a portion of the ultrasonic waveguide  179 . The damping sheath  110  may be positioned around the ultrasonic waveguide  179  to dampen or limit transverse side-to-side vibration of the ultrasonic waveguide  179  during operation. The damping sheath  110  preferably surrounds part of the second section  184  of the ultrasonic waveguide  179 . It is contemplated that the damping sheath  110  may be positioned around any suitable portion of the ultrasonic waveguide  179 . The damping sheath  110  preferably extends over at least one antinode of transverse vibration, and more preferably, a plurality of antinodes of transverse vibration. The damping sheath  110  preferably has a substantially circular cross-section. It will be recognized that the damping sheath  110  may have any suitable shape to fit over the ultrasonic waveguide  179  and may be any suitable length. 
         [0106]    The damping sheath  110  is preferably in light contact with the ultrasonic waveguide  179  to absorb unwanted ultrasonic energy from the ultrasonic waveguide  179 . The damping sheath  110  reduces the amplitude of non-axial vibrations of the ultrasonic waveguide  179 , such as, unwanted transverse vibrations associated with the longitudinal frequency of 55,500 Hz as well as other higher and lower frequencies. 
         [0107]    The damping sheath  110  is constructed of a polymeric material, preferably with a low coefficient of friction to minimize dissipation of energy from the axial motion or longitudinal vibration of the ultrasonic waveguide  179 . The polymeric material is preferably floura-ethylene propene (FEP) which resists degradation when sterilized using gamma radiation. It will be recognized that the damping sheath  110  may be fabricated from any suitable material, such as, for example, PTFE. 
         [0108]    The damping sheath  110  preferably has an opening extending therethrough, and a longitudinal slit  111 . The slit  111  of the damping sheath  110  allows the damping sheath  110  to be assembled over the ultrasonic waveguide  179  from either end. It will be recognized that the damping sheath  110  may have any suitable configuration to allow the damping sheath  110  to fit over the ultrasonic waveguide  179 . For example, the damping sheath  110  may be formed as a coil or spiral or may have patterns of longitudinal and/or circumferential slits or slots. It is also contemplated that the damping sheath  110  may be fabricated without a slit  111  and the ultrasonic waveguide  179  may be fabricated from two or more parts to fit within the damping sheath  110 . 
         [0109]    It will be recognized that the ultrasonic waveguide  179  may have any suitable cross-sectional dimension. For example, the ultrasonic waveguide  179  may have a substantially uniform cross-section or the ultrasonic waveguide  179  may be tapered at various sections or may be tapered along its entire length. 
         [0110]    The ultrasonic waveguide  179  may also amplify the mechanical vibrations transmitted through the ultrasonic waveguide  179  to the ultrasonic blade  88  as is well known in the art. The ultrasonic waveguide  179  may further have features to control the gain of the longitudinal vibration along the ultrasonic waveguide  179  and features to tune the ultrasonic waveguide  179  to the resonant frequency of the system. 
         [0111]    The proximal end of the third section  186  of ultrasonic waveguide  179  may be coupled to the distal end of the second section  184  by an internal threaded connection, preferably near an antinode. It is contemplated that the third section  186  may be attached to the second section  184  by any suitable means, such as a welded joint or the like. Third section  186  includes ultrasonic blade  88 . Although the ultrasonic blade  88  may be detachable from the ultrasonic waveguide  179 , the ultrasonic blade  88  and ultrasonic waveguide  179  are preferably formed as a single unit. 
         [0112]    The ultrasonic blade  88  may have a length substantially equal to an integral multiple of one-half system wavelengths (nλ/2). The distal end of ultrasonic blade  88  may be disposed near an antinode in order to provide the maximum longitudinal excursion of the distal end. When the transducer assembly is energized, the distal end of the ultrasonic blade  88  is configured to move in the range of, for example, approximately 10 to 500 microns peak-to-peak, and preferably in the range of about 30 to 150 microns at a predetermined vibrational frequency. 
         [0113]    The ultrasonic blade  88  is preferably made from a solid core shaft constructed of material which propagates ultrasonic energy, such as a titanium alloy (i.e., Ti-6Al-4V) or an aluminum alloy. It will be recognized that the ultrasonic blade  88  may be fabricated from any other suitable material. It is also contemplated that the ultrasonic blade  88  may have a surface treatment to improve the delivery of energy and desired tissue effect. For example, the ultrasonic blade  88  may be micro-finished, coated, plated, etched, grit-blasted, roughened or scored to enhance coagulation and cutting of tissue and/or reduce adherence of tissue and blood to the end-effector. Additionally, the ultrasonic blade  88  may be sharpened or shaped to enhance its characteristics. For example, the ultrasonic blade  88  may be blade shaped, hook shaped, or ball shaped. 
         [0114]    Referring now to  FIGS. 1-4 , the procedure to attach and detach the clamp coagulator  120  from the acoustic assembly  80  will be described below. When the physician is ready to use the clamp coagulator  120 , the physician simply attaches the clamp coagulator  120  onto the acoustic assembly  80 . To attach the clamp coagulator  120  to acoustic assembly  80 , the distal end of stud  50  is threadedly connected to the proximal end of the transmission component or ultrasonic waveguide  179 . The clamp coagulator  120  is then manually rotated in a conventional screw-threading direction to interlock the threaded connection between the stud  50  and the ultrasonic waveguide  179 . 
         [0115]    Once the ultrasonic waveguide  179  is threaded onto the stud  50 , a tool, such as, for example, a torque wrench, may be placed over the elongated member  150  of the clamp coagulator  120  to tighten the ultrasonic waveguide  179  to the stud  50 . The tool may be configured to engage the wrench flats  169  of the hub  162  of the outer tube  160  in order to tighten the ultrasonic waveguide  179  onto the stud  50 . As a result, the rotation of the hub  162  will rotate the elongated member  150  until the ultrasonic waveguide  179  is tightened against the stud  50  at a desired and predetermined torque. It is contemplated that the torque wrench may alternately be manufactured as part of the clamp coagulator  120 , or as part of the hand piece housing  20 , such as the torque wrench described in U.S. Pat. No. 5,776,155 hereby incorporated herein by reference. 
         [0116]    Once the clamp coagulator  120  is attached to the acoustic assembly  80 , the surgeon can rotate the rotational knob  190  to adjust the elongated member  150  at a desired angular position. As the rotational knob  190  is rotated, the teeth  269  of the tubular collar  260  slip over the pawls  286  of the yoke  280  into the adjacent notch or valley. As a result, the surgeon can position the end-effector  180  at a desired orientation. Rotational knob  190  may incorporate an indicator to indicate the rotational relationship between instrument housing  130  and clamp arm  202 . As illustrated in  FIGS. 17 and 18 , one of the ridges  197  of rotational knob  190  may be used to indicate the rotational position of clamp arm  202  with respect to instrument housing  130  by utilizing, for example, an enlarged ridge  200 . It is also contemplated that alternate indications such as the use of coloring, symbols, textures, or the like may also be used on rotational knob  190  to indicate position similarly to the use of enlarged ridge  200 . 
         [0117]    To detach the clamp coagulator  120  from the stud  50  of the acoustic assembly  80 , the tool may be slipped over the elongated member  150  of the surgical tool  120  and rotated in the opposite direction, i.e., in a direction to unthread the ultrasonic waveguide  179  from the stud  50 . When the tool is rotated, the hub  162  of the outer tube  160  allows torque to be applied to the ultrasonic waveguide  179  through the pin  163  to allow a relatively high disengaging torque to be applied to rotate the ultrasonic waveguide  179  in the unthreading direction. As a result, the ultrasonic waveguide  179  loosens from the stud  50 . Once the ultrasonic waveguide  179  is removed from the stud  50 , the entire clamp coagulator  120  may be thrown away. 
         [0118]    While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.

Technology Category: a