Abstract:
Surgical instruments are disclosed in which an elongated shaft is used in conjunction with a separate, remotely actuable tool head for performing a procedure on a target tissue. The shaft has a tool engagement member carried at its distal end that is remotely actuable through the shaft to engage and release the tool head.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. Nonprovisional patent application Ser. No. 12/061,319, filed Apr. 2, 2008 now abandoned, which claimed priority to Provisional Patent Application Ser. No. 60/909,666, filed Apr. 2, 2007, the disclosures of earn of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present application is related to surgical instruments and, more specifically but not exclusively, to robotic surgery instruments and methods for their use. Specifically, the present application relates to the provision of a plurality of specially configured tool heads for use with a control arm, which may be a robotic arm of a robotic surgical instrument, having an elongated shaft and preferably an articulatable “wrist” or articulation joint located at its distal or working end. 
     The tool heads disclosed and described herein are particularly, but not exclusively, suited for use in cardiac ablation procedures for the treatment of atrial fibrillation using electro-surgical RF energy, or some other energy, as shown and described for example in U.S. Pat. No. 6,546,935, which is incorporated herein by reference. 
     During the performance of cardiac ablation procedures, various instruments may be used to create transmural lines of ablation in tissue, such as an ablation clamp having opposed jaw members having opposed electrodes thereon, an ablation “pen” and a surgical dissector. Such instruments are shown generally in U.S. Pat. No. 7,113,831 and U.S. Published Application 2006/0084974 (showing an ablation clamp with opposed jaw members), U.S. Published Applications 2006/0161147 and 2006/0161149 (both showing an ablation pen), and U.S. Published Application 2005/0203561 (showing a lighted dissector), all of which are incorporated herein by reference. In another procedure, a clip may be applied externally to the left atrial appendage (LAA) to reduce the risks of clot generation associated with the LAA. Such a clip and clip applicator are shown in U.S. application Ser. No. 12/033,935, filed Feb. 20, 2008, which is also incorporated herein by reference. Each of the aforementioned devices or tools is typically carried on its own dedicated hand piece and a shaft, with the operating head at the distal end thereof. 
     SUMMARY 
     By way of the present application, tools for performing cardiac ablation and other procedures are provided as discrete interchangeable independent devices or tool heads that are intended to be used with a control arm, such as a robotic arm or a durable, e.g., reusable, arm. The tool heads are provided with a tether connected directly thereto to provide for actuation of the tool head. (As used herein, “actuation” or “actuable” are broadly understood to mean energizing or controlling the tool head mechanically, hydraulically, pneumatically, thermally, or activating a light/laser/light pipe/fiber optic, or providing a vacuum/suctionor fluid delivery and the like, as well as combinations thereof.) Specifically, each of the tool heads may include at least one gripping or clamping surface designed to be carried by the jaws of a forceps or grasper mounted to the distal end of the shaft of the control arm. The tool head may be removably mounted to the control arm in any of a variety of ways described below, or by other mounting arrangements. 
     The actuation and/or energizing means for generating movement is preferably connected to the tool head separate from the control arm in a manner that permits remote actuation/energization of the tool head, (i.e. external to the body) independent of the control arm after the tool heads have been introduced, for example, by minimally invasive means, to a surgical site interior of the body. 
     Because the tool head is completely independent from the control arms, the tool head may be passed from one control arm to another control arm, or exchanged between control arms, and the various tools may be selectively grasped by the control arm to permit instrument exchanges during procedures. The tool heads may be introduced either through the same access port as the control arm or through a separate access port, into the surgical site. Thus, in a procedure, all of the tool heads needed for the procedure may be separately introduced into proximity of the surgical site, such as into a cavity at the start of the procedure and be readily available for use in connection with one or more control arms. 
     In one embodiment, the tool heads are provided with an extending or fin-like surface for gripping by jaws of a control arm. Preferably, the fins are made of a material having some compressibility, which allows the jaws of control arm forceps to better grip and hold the tool head. 
     Additionally, or alternatively, the fin and the forceps may be formed with complementarily-shaped interfitting surfaces that mate when the tool is gripped by the forceps. Such surfaces may be shaped to provide selected alignment of the tool with respect to the forceps. In one embodiment, for example, the jaws of the forceps of the control arm have an open or relieved interior or apertures or fenestrations and the gripping surfaces of the tool heads may be formed with one or more complementarily-shaped protrusion that is received within the fenestration interior of the jaws. 
     In a further alternative, these surfaces may be reversed, and the gripping or clamping surface may comprise a pocket or aperture that receives the closed jaws or projecting surfaces thereof and may be grasped by moving the jaws toward their open position. 
     As another option, the tool heads may be formed with two or more gripping surfaces, which permits a tool head to be simultaneously held by two or more control arms so that the tool head can be passed from a first control arm to a second control arm, and allows for both control arms to work in unison. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a control arm having an articulatable wrist and a grasper at its distal end. 
         FIG. 2  is a perspective view of the distal end of the control arm of  FIG. 1  and a tool head in the form of an ablation clamp in accordance with the present disclosure. 
         FIG. 3  is a perspective view similar to  FIG. 3  in which the tool head is held by the control arm. 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a perspective view of the distal end of the control arm of  FIG. 1  and a tool head in the form of a blunt dissector in accordance with the present disclosure. 
         FIG. 6  is a perspective view similar to  FIG. 5  in which the tool head is held by the control arm. 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 6 . 
         FIG. 8  is a perspective view of the distal end of the control arm of  FIG. 1  and a tool head in the form of a clip applicator in accordance with the present disclosure. 
         FIG. 9  is a perspective view similar to  FIG. 8  in which the tool head is held by the robotic arm. 
         FIG. 10  is a cross-sectional view taken along line  10 - 10  of  FIG. 9 . 
         FIG. 11  is a perspective view of the distal end of the control arm of  FIG. 1  and a tool head in the form of an ablation pen in accordance with the present disclosure. 
         FIG. 12  is a perspective view similar to  FIG. 11  in which the tool head is held by the control arm. 
         FIG. 13  is a cross-sectional view taken along line  13 - 13  of  FIG. 12 . 
         FIG. 14  is a perspective view similar to  FIG. 11  except that it has an alternative clamping surface. 
         FIG. 15  is a perspective view similar to  FIG. 14  in which the tool head is held by the control arm. 
         FIG. 16  is a cross-sectional view taken along line  16 - 16  of  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , there is seen one form of a control arm with which the surgical instruments disclosed herein are adapted to be used. The illustrated control arm is a robotic arm  10  comprising a component of a telesurgical system (not shown), such as the daVinci Surgical System, available from Intuitive Surgical, Inc. of Mountain View, Calif., shown in U.S. Pat. No. 6,770,081, which is incorporated herein by reference. Alternatively, the control arm is not necessarily a robotic arm or associated with a robotic surgical system, although that is one system in which this subject matter has particular application. For example, the control arm may simply be a standard surgical grasping tool such as those available from Fehling Surgical Instrument, Inc., of Acworth, Ga., or graspers of the type disclosed in U.S. Pat. No. 5,728,121, which is incorporated herein by reference. 
     The illustrated robotic arm  10  includes an elongated shaft  12  and a wrist-like articulation mechanism  14  at its distal end. A housing  16  at the proximal end of the assembly  10  couples the assembly to the telesurgical system. The housing  16  contains the mechanism for controlling (e.g., rotating) the shaft  12 , articulating the wrist  14 , and actuating a forceps  18  mounted to the wrist mechanism  14  carried on the distal end of the shaft  12 . The illustrated forceps  18  is known as a cardiere forceps in which the jaws  20  are fenestrated, or otherwise have an opening or relief in their gripping surface. Preferably, and as shown, the gripping surfaces of the jaws are serrated. 
     With reference to  FIGS. 2-4 , there is seen a tool head  22  comprising an clamp having opposed jaws  24 ,  26  for use with the robotic arm assembly  10  shown in  FIG. 1 . The illustrated clamping jaws  24 ,  26  may preferably be as shown and described in U.S. Pat. No. 7,113,831 and U.S. Published Application 2006/0084974. Each jaw  24 ,  26  includes an elongated electrode (not shown) that is adapted to receive bipolar RF energy for creating transmural ablation lines in tissue held between the jaws  24 ,  26 . Jaw  24  may be stationary, while jaw  26  may be moveable toward and away from jaw  26 , with the mating surfaces of the jaws  24 ,  26  remaining substantially parallel. The electrical and mechanical connections  28  for activating the electrodes carried on the jaws and for opening and closing the jaws are connected to the tool head  22  separate and independent from the control arm, such as shaft  12  of the robotic tool  10 . 
     Because the activation sources for the tool head are separate from the control arm, the tool head may be exchanged between different control arms, the tool head may be released from the control arm and a different tool head attached, and multiple tool heads may be preselected and placed in or near the surgical site for user convenience. This feature has particular benefit in a minimally invasive surgery in that, for example, the tool heads expected to be needed for a selected surgery may be inserted in to the body cavity, creating what may be referred to as a tool kit or tool chest within the body cavity, and the surgeon or robotic instrument may use a single control arm for grasping and using each tool head, as needed, without the need for repeatedly removing the control to exchange or replace tools as needed. Further, the tool heads may be for one-time use only and disposable, with the control arm, and any associated articulation control mechanism, being reusable, if so desired. 
     To facilitate the grasping of the individual tool head  22  by the grasper  18 , the tool head  22  may be provided, in one embodiment, with a clamping surface  30 . Specifically, the illustrated clamp carries a generally flat or fin-like protrusion on the side of the tool opposite the jaw members  24 ,  26 , although other configurations for the clamping surface or other arrangements other than a clamping surface are also contemplated. In order to enhance the grip of the jaws on the clamping surface, the fin  30  has opposed protrusions  32  sized and shaped to fit into the fenestrations  20   a  on the jaws  20  of the forceps  18 . As shown, the protrusions  32  are formed on both surfaces of the clamping surface, although a protrusion could be formed on only one of the clamping surfaces. Also, if the fenestration  20   a  and protrusion  32  are complementarily shaped, such as one concave and the other convex, and non-circular, gripping of the tool head  22  in a particular orientation to the jaws  20  is facilitated. 
     As noted above, it is contemplated that other tools or tool heads useful in performing cardiac ablation or other intended procedures could similarly be provided with a clamping or gripping surface or other grasping arrangement. Turning to  FIGS. 5-7 , a tool head  34  in the form of a blunt dissector is shown in combination with the working end of a control arm such as a robotic shaft. The illustrated dissector  34  may preferably be as shown and described in U.S. Published Application 2005/0203561. The dissector comprises an arcuate section  36  with a smooth outer surface and a generally circular cross-sectional shape. However, the geometry may vary depending on the targeted anatomy. The arcuate section  36  has a blunt and rounded distal end  38 . As illustrated, the distal end of the dissector  35  includes a light source  40  that emits visible energy. The light source  40  is powered by a battery carried in housing  42  that is connected to the dissector  35  by an insulated conductor/tether  44  such that the battery remains external to the body during a procedure. The battery housing  42  includes a switch  46  for activating the light source  40 . To facilitate the grasping of the dissector  34  by the jaws  20  of the forceps  18 , the dissector  35  includes a clamping surface  48  at its proximal end having at least one and preferably opposed posts  50  adapted to be received in the fenestrations  20   a  of the opposed jaws  20 . 
       FIGS. 8-10  show the working end of the robotic shaft in combination with tool head  52  comprising a clip applicator for applying an occlusion clamp or clip to the tissue to be closed, which may include the left atrial appendage, or other vessel or tissue. The clip applicator and clip may be as shown and described in pending U.S. patent application Ser. No. 12/033,935, filed Feb. 20, 2008. The tool head comprises a frame  54  with an open interior with a fabric covered clip  56  preloaded therein. The clip  56  comprises two legs  58 ,  60  that are spread apart a distance sufficient to allow it to be placed over target tissue, e.g., the left appendage of the heart. To this end control sutures, wires or strings  62  are attached to leg  60  of the clip such that retraction of the sutures  62  spreads the legs  58 ,  60 . The proximal end of the sutures  62  remain external to the body for remote actuation. For cooperation with a control arm, the clip applicator  52  includes a clamping surface  64  with elongated protrusions  66  similar to that shown in conjunction with the ablation clamp  22  described above. In addition, the clip applicator  52  is provided with a second clamping surface  68  similar to clamping surface  64  and having elongated protrusions  70 . The second clamping surface permits the tool head  52  to be grasped simultaneously by two robotic arm assemblies  10 , thus permitting the tool head to be passed from one robotic arm to a second robotic arm. This feature is not limited to a clip applicator, and as such, each of the tool heads described herein may also include a second clamping surface. 
       FIGS. 11-13  show an ablation pen  72  in combination with the distal end of the control arm of a robotic surgical instrument. The ablation pen  72  may preferably be as shown and described in U.S. Published Applications 2006/0161147 and 2006/0161149. The ablation pen  72  includes a head  74  carrying two electrodes (not shown) capable of being energized with bi-polar RF energy. An insulated electrical conductor  76  is provided (as a tether) for transmitting energy to the electrodes. 
     Similar to the examples described above, the pen  72  is provided with a clamping surface  78  adapted to be held between the jaws  20  of the forceps  18 . As seen in  FIG. 11 , the clamping surface  78  does not include the complementarily-shaped protrusions associated with the clamping surfaces of the previously disclosed embodiments. Instead, the clamping surface  78  is made from or provided with a covering of a compressible material that is more readily deformable under the closing force achieved by the jaws  20 , thus permitting the jaws  20  to more firmly grip the clamping surface  78 . This is shown in  FIG. 13 , where it can be seen that the clamping surface  78  has been deformed such that a portion  80  thereof resides in the fenestrations of the jaws  20 . As can be appreciated, the clamping surface of the tool head may be both deformable and have complementarily-shaped protrusions to enhance gripping by a forceps. Other friction-enhancing materials or surfaces may be used to enhance grasping by the control arm. 
     While each of the tool heads described thus far has had a clamping surface adapted to be held between the closed jaws of a forceps, other configurations for securing the tool head are contemplated. For example, and with reference to  FIGS. 14-16 , the tool head  72  (shown for illustrative purposes in the form of an ablation pen as in  FIGS. 11-13 ) is provided by a receptacle  84 , which may also be referred to as a clamping surface, that is adapted to be held by the spread-apart or open jaws of the forceps. Specifically, the clamping surface  84  is in the form of a pocket or sleeve with an open interior sized to receive the closed jaws  20  of the forceps  8 . The pocket or sleeve  84  has opposed side walls  86  that are engaged by the outer surface of the jaws  20  (best seen in  FIG. 16 ). Of course, as described in connection with the outer embodiments, the interior of the sleeve may be provided with protrusions sized to be received in the fenestrations of the jaws and/or a deformable or enhanced friction surface. 
     While the surgical instruments have been described in terms of those particularly appropriate for cardiac applications, this is not by way of limitation, but for illustration. Indeed, any surgical instruments adapted for use with robotic devices may advantageously include the clamping surface described above.