Abstract:
A surgical device comprises an external sheath having a proximal end and a distal end for insertion through an opening of a body and a plurality of tool components extending from the distal end of the external sheath. The tool components are independently deflectable with respect to each other and with respect to the external sheath and removable from the device without requiring withdrawal of the sheath through the opening of the body. The external sheath is flexible and deflectable intermediate the distal and proximal ends. This permits the device to be steered in a curvilinear manner towards a surgical target.

Description:
PRIORITY CLAIM 
       [0001]    The present application claims the benefit of copending U.S. Provisional Patent Application Ser. No. 61/261,310, filed Nov. 14, 2009; the present application also claims the benefit of copending U.S. Provisional Application Ser. No. 61/293,932, filed Jan. 11, 2010; the present application also claims the benefit of copending U.S. Provisional Application Ser. No. 61/315,018, filed Mar. 18, 2010; all of the foregoing applications are incorporated herein by reference in their entireties. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention is directed to a surgical device. The present invention is more particularly directed to a surgical device for use in robotic surgery, such as for example, in robotic neurosurgery. Still further, the device permits access to surgical sites that may be most desirably accessed over a curvilinear path. 
         [0003]    Surgery has typically involved obtaining access to a region that exposes many aspects of a lesion (e.g. tumor, aneurysm, etc.) allowing its treatment or complete dissection and removal. However, obtaining access to the lesion may also involve damage to areas of the brain or other tissues that are normal. In view of the foregoing, a movement has developed to perform what is called “Minimally Invasive Surgery.” Unfortunately, this, in many instances, is a misnomer since the surgery may or may not be “minimally invasive” both to the critical tissues under consideration, but also to collateral tissues at the site of entry or along the access path. A better term for this type of surgery is “Minimal Access Surgery.” Examples of such surgery include: Endoscopic Surgery, Endoscope Assisted Surgery, Endovascular Surgery, Stereotactic Radiosurgery, etc. 
         [0004]    It is often necessary to treat brain tumors and aneurysms in the base of the skull. These are very difficult to treat because accessing the skull base requires disruption of many important structures. It is desirable to minimize the size of any opening to be made through the skull and surrounding, healthy tissues so that pathology in the skull base is treated with the least amount of potential damage to surrounding tissues. Such a procedure could be thought of as “Minimally Disruptive Surgery.” Current endoscopic and endoscope-assisted operations performed on the head, skull base, chest, abdomen, and other areas are done with rigid and straight endoscopes and tools that can only work in a straight line. However, in complex areas such as the brain, the endoscope has to negotiate many obstacles en route (e.g. bone, brain, and blood vessels). This imposes significant restrictions on the surgery being performed and can lead to an increase in collateral tissue damage, due to enlarging the access path and/or damaging or sacrificing the control over the structures near the lesion. Additionally, there are certain types of surgery that are at present not possible given the limitations posed by existing technology. 
         [0005]    On the other hand, today&#39;s endovascular surgery is often performed over comparatively great distance, and by navigating through a variety of curved channels. Such surgery uses a system of coaxial tubes and actuation cables that work on the basis of forward and backward movement, and side-to-side movement. Such devices are used with real-time imaging that guides the operator to the target. A similar approach is used with flexible endoscopes that work inside the gastrointestinal tract. However, these methods are not applicable for microscale surgeries, as are performed for intricate neurosurgeries. 
         [0006]    In addition to the foregoing, it is sometimes desirable during surgical procedures to irrigate a surgical site, clean surgical tools, or repeatedly remove and re-introduce surgical tools. This presents a problem with currently known robotic surgical systems because removal of the entire system is generally required to change tools. 
         [0007]    The present invention overcomes these and other challenges. It provides a surgical device capable of steering surgical tools to surgical sites over curvilinear neurosurgery paths to avoid unnecessary damage to sensitive or critical collateral tissue. The device is capable of steering surgical tools around anatomical obstacles while affording the tools complete maneuverability at the surgical site and removal/replacement during neurosurgical procedures. 
       SUMMARY 
       [0008]    In one embodiment of the invention, a surgical device comprises an external sheath having a proximal end and a distal end for insertion through an opening of a body and a plurality of tool components extending from the distal end of the external sheath. The tool components are independently deflectable with respect to each other and with respect to the external sheath and removable from the device without requiring straightening or withdrawal of the sheath through the opening of the body. 
         [0009]    The device may further include a deflection control assembly that controls the deflection of the tool components from the proximal end of the external sheath. The deflection control assembly may comprise a deflectable tool support associated with and arranged to receive at least one of the tool components so that deflection of the deflectable tool support causes its associated tool component to be deflected. The deflectable tool support may comprise a coil spring. The deflection control assembly may comprise a plurality of pull cables that extend from the deflectable tool support to the proximal end of the external sheath. 
         [0010]    The device may further comprise a joy stick at the proximal end of the external sheath and coupled to the plurality of pull cables. 
         [0011]    The device may further comprise a support base that supports the deflectable tool support. The support base is movable beyond the distal end of the external sheath. The support base is biased to project outward from the external sheath when moved beyond the distal end of the external sheath. 
         [0012]    The device may further include a flexible guide tube associated with each of the deflectable tool supports that runs from the proximal end of the device to the distal end of the device. The guide tubes may be used to remove and reinsert tool components during a procedure without requiring the device to be straightened or removed from the patient. 
         [0013]    Each of the tool components may include an elongated flexible shaft that extends proximally from the distal end of the external sheath, through the external sheath and out the proximal end of the external sheath. Each tool component is thus removable from the device by removal of its elongated flexible shaft from the proximal end of the external sheath. 
         [0014]    Tool components may include mechanical instruments including, without limitation, graspers, shears, biopsy forceps, and clip appliers. Tool components may also include electrical instruments including, without limitation, electrocautery devices, lasers, and high-intensity focused ultrasound (HIFU) fibers. Tool components may also include other equipment or implantable devices including, without limitation, aneurysm clips, fibrin glue, radioactive seeds for tumors, chemotherapeutic wafers, gel injections, shunts, reservoirs for medication delivery, nano-particle conjugates, future downsized ultrasound tips, and/or other foreign bodies. 
         [0015]    The external sheath is flexible and deflectable intermediate the distal and proximal ends. This permits the device to be steered in a curvilinear manner towards a surgical target. 
         [0016]    The device may further comprise a flexible guidance tube arranged to receive a tool component and that allows for removal and reinsertion of the tool component without requiring the device to be straightened or removed from the body. The flexible guidance tube may be arranged to facilitate suction and irrigation of the surgical site, with or without removal of the tool component. The flexible guidance tube may be further arranged to facilitate the cleaning of the tool component without requiring removal of the tool component. 
         [0017]    The device may further comprise a plurality of sliding control rings at the proximal end of the external sheath that control the deflection of the flexible portion of the sheath. 
         [0018]    The device may further comprising a joystick at the proximal end of the sheath. Control of the deflectable degrees of freedom of the device may be divided between the sliding control rings and the joystick. 
         [0019]    According to another embodiment, a surgical device comprises an external sheath having a proximal end and a distal end for insertion through an opening of a body. The sheath is flexible and bendable intermediate the distal end and proximal end. The device further includes a plurality of tool components extending from the distal end of the external sheath. The tool components are independently deflectable with respect to each other and with respect to the external sheath. 
         [0020]    According to a still further embodiment, a surgical device comprises an external sheath having a proximal end and a distal end for insertion through an opening of a body. The sheath is flexible and bendable intermediate the distal end and the proximal end. The device further includes a plurality of tool components extending from the distal end of the external sheath. The tool components are independently deflectable with respect to each other and with respect to the external sheath. The tool components are also removable from the device without requiring straightening or withdrawal of the sheath through the opening of the body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further features and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify identical elements, and wherein: 
           [0022]      FIG. 1  is perspective view of a surgical device embodying the present invention; 
           [0023]      FIG. 2  is a perspective view, to an enlarged scale, of a deflection control assembly that may be employed to impart deflection control of a pair of surgical instruments according to one embodiment of the invention; 
           [0024]      FIG. 3  is a perspective view, to an enlarged scale, of the deflection control assembly of  FIG. 2  after receiving a pair of surgical instruments according to one embodiment of the invention; 
           [0025]      FIG. 4  is a perspective view, to an enlarged scale, of the deflection control assembly of  FIG. 2  controlling the positioning of the pair of surgical instruments according to one embodiment of the invention; 
           [0026]      FIG. 5  is a plane end view of the head assembly at the distal end of the device  FIG. 1 ; and 
           [0027]      FIG. 6  is a side view of the tool support bases illustrating a manner in which the support bases may be projected outward upon being moved distally to the sheath distal end. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]      FIG. 1  shows a surgical device  10  embodying the present invention. The device generally includes an external sheath  20 , a deflection control assembly  40 , and a controller  90 . The device  10  has a proximal end  12  and a distal end  14 . 
         [0029]    The sheath  20  has a substantially rigid portion  22  and a flexible portion  24 . The sheath has an internal channel  26  that permits surgical tool components and control cables to pass there through as described subsequently. The flexible portion  24  of the sheath  10  is bendable or steerable between the proximal end  12  and the distal end  14  as indicated by arrows  28  and  30  to render the distal end  14  of device  10  steerable. This allows the distal end  14  to be directed in a curvilinear manner once inserted through an opening of a body and advanced towards a surgical target. This is particularly advantageous for use in surgeries wherein advancement of the sheath around sensitive or vital tissue or anatomical structures is required. 
         [0030]    The controller  90  at the proximal end  12  of the device  10  is arranged to control the steering movement of the flexible portion  24  of the sheath  20 , the general placement of the tools  42  and  44  at the distal end  14 , and the movement of the tools  42  and  44 , once placed. With respect to the general placement of the tools, the end view of  FIG. 5  shows a head assembly at the distal end of the sheath  20 . 
         [0031]    The head assembly includes tool supports  48  and  50 . Each tool support includes a channel for receiving a tool. To that end, the tool support  48  includes tool channel  52  and tool support  50  includes tool channel  54 . Each tool support also includes a coiled spring. To that end, tool support  48  includes coiled spring  56  and tool support  50  includes coiled spring  58 . While cutting tool components are illustrated herein, it is to be understood that other tool components may be controlled as well including visualization tools, other surgical tools and suction/irrigation tools, for example. Each tool support also makes provision for at least three pull cables to deflect the coiled springs  56  and  58 . To this end, tool support  48  includes cable channels  60 ,  62 , and  64 , and tool support  50  includes cable channels  66 ,  68 , and  70 . 
         [0032]    The head assembly  46  also makes provision for visualization during a surgical procedure. To this end, the head assembly further includes channels  80  and  82 . One of channels  80  or  82  may accommodate a light source, such as a fiber optic cable, for example, while the other of the channels  80  or  82  may accommodate a camera. The light source and camera may also be incorporated into a single device occupying one of the channels  80  or  82 , and allowing the other of the channels  80  or  82  to be occupied by an alternate device such as a suction or irrigation tube or a cauterizing fiber. 
         [0033]      FIG. 2  shows the head assembly  46  in perspective and to an enlarged scale. Here it may be seen the coiled spring  56  terminates with a ring member  57  and coiled spring  58  terminates with a ring member  59 . The aforementioned pull cables are attached to the ring members  57  and  59 . For example, pull cables  51 ,  53 , and  55  are attached to ring  57  of coiled spring  56 . Similarly, pull cables  61 ,  63 , and  65  are attached to ring  59  of coiled spring  58 . The pull cables extend from their associated coiled springs, through the cable channels and proximally to the controller  90 . 
         [0034]    Referring again to  FIG. 1 , the controller  90  includes a controller base  92  that is fixed with respect to the rigid portion  22  of the sheath  20 . A controller adapter  94  is secured to the rigid portion  22  of the sheath  20 . It is also secured to the controller base by a pair of rails  96  and  98 . The controller base carries a pair of joy stick controls  100  and  102 . The joy stick controls control the pulling on the pull cables  51 ,  53 , and  55  and  61 ,  63 , and  65  associated with coiled springs  56  and  58 , respectively. As may be seen in  FIG. 1 , pull cables  51 ,  53 , and  55  associated with coiled spring  56  are couple to joy stick  102 . Similarly, pull cables  61 ,  63 , and  65  are coupled to joy stick  100 . Hence, joy stick  102  controls the deflection of coiled spring  56  and joy stick  100  controls the deflection of coiled spring  58 . 
         [0035]      FIG. 3  shows surgical tool components  44  and  42  being received by the coiled springs  56  and  58  respectively. The tool supports  48  and  50  are projecting outwardly to separate the tools  44  and  42 . As best seen in  FIG. 6 , the tool supports  48  and  50  are mounted for pivotal movement about a pivot axis  67 . The tool supports  48  and  50  are biased to project outwardly. The bias may be provided in the tool supports, for example, by the shape of the tool supports, as in a slight interference fit between the tool supports to cause their separation. 
         [0036]    As may be seen in  FIG. 3 , with coil spring  56  receiving tool  44 , any deflection in coil spring  56  by joy stick  102  ( FIG. 1 ) will impart a similar deflection in tool  44 . Similarly, with coil spring  58  receiving tool  42 , any deflection in coil spring  58  by joy stick  100  ( FIG. 1 ) will impart a similar deflection in tool  42 . In this manner, the general placement of tools  42  and  44  may be controlled. Hence, the tool supports and coiled springs form deflection control assemblies for deflecting their associated tools. 
         [0037]    As may also be seen in  FIG. 3 , each tool includes a flexible shaft. To this end, tool  44  includes flexible shaft  45  and tool  42  includes flexible shaft  43 . The shafts  43  and  45  extend through flexible guide tubes  73  and  75 , respectively. The guide tubes  73  and  75  extend from the rings  59  and  57 , respectively, proximally out the proximal end of the sheath  20  to finger loop interfaces  103  and  105 , respectively. Such interfaces are well known in the art. The control loops  107  and  109  are coupled to the flexible tool shafts  43  and  47 . The tools  42  and  44  are thus removable from the device by the pulling of the flexible tool shafts  43  and  45  out of the guide tubes  73  and thus out of the device. Hence, the tools  42  and  44  are removable from the device without the device having to be straightened or removed from the patient. This facilitates ready cleaning of the tools or replacement of the tools with similar or different tools. 
         [0038]    The guides tubes  73  and  75 , in addition to providing guidance of the tools  42  and  44  and the tool shafts  43  and  45  may also perform other functions. For example, one or both guide tubes may be used for irrigation and/or suction at the surgical site. The guide tubes may have a cross-sectional dimension greater than the cross-sectional dimension of the tools. Thus, when a tool is within a guide tube, a space running along the tube between the tube and the tool is provided. The guide tubes may thus be used for irrigation and/or suction with or without the tool components in place. With the tool components in place, irrigation can also be used to clean the tool tips without requiring their removal. 
         [0039]      FIG. 4  shows that once the tools  42  and  44  are separated, they may be manipulated, as by being brought together, by the deflection of the coil springs  56  and  58  facilitated by the operation of the joy sticks  100  and  102 . Once the tools  42  and  44  are at the surgical site through general placement of each tool  42  and  44 , the tools may be rotated or moved in and out by operation of its associated control ring  107  and  109 . 
         [0040]    The flexing of the flexible portion  24  of the sheath  20  may be controlled by sliding control rings  104  and  106 . The rings  104  and  106  are arranged to slide along rails  96  and  98  (a third rail is not visible in  FIG. 1 , as it is hidden by the flexible tool shafts). Each one of rings  104  and  106  is coupled to a control cable (not shown) that is connected to the inside wall of the flexible portion  24  of the sheath  20 . Pulling or pushing on one of the rings causes the flexible portion  24  of the sheath to deflect in one plane, while pulling or pushing on the other one of the rings causes the flexible portion  24  of the sheath  20  to deflect in a perpendicular plane. In this manner, the device may be steered along a curvilinear path to the surgical site. 
         [0041]    As may be seen from the foregoing, the present invention provides an improved surgical device that permits surgical instruments to reach remote portions of the body with reduced trauma. The device sheath may be steered to a surgical site around sensitive or critical tissue. The surgical tool components may be removed for replacement or cleaning without the device having to be straightened or removed from the body. Further, the tool deflection assemblies and methodology renders precise control of the surgical tool components in all required degrees and directions of movement. The present invention is thus well suited for use in many different applications, including robotic surgical systems. 
         [0042]    While a particular embodiment of the invention has been shown and described, changes and modifications may be made. It is therefore intended to cover in the appended claims all such changes and modifications which fall within the true spirit and scope of the invention.