Abstract:
Tools for accessing tissue are described for use with a locatable guide of a navigation system. In preferred embodiments, said tools are attachable to a distal tip of a locatable guide, such that the location of the tool, preferably in six degrees of freedom, is known while the tool is being used.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 61/139,501 filed Dec. 19, 2008 entitled Biopsy Tools, which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Identifying and treating lung tissue abnormalities presents challenges that are somewhat unique to the lungs. If a tissue lesion or tumor is to be identified and excised surgically, the chest wall must be opened to provide access to the lungs. Opening the chest wall is a common procedure but one that presents risks of infection and lengthy recovery time, nonetheless. If a tissue lesion or tumor is to be identified endoscopically, the complicated bronchial maze must be navigated. 
         [0003]    Technology has been developed that allows a physician to track, in real-time, the position of a probe (hereinafter “locatable guide” or “LG”) traveling through the airways. This technology incorporates a plurality of coils at the end of an LG and a magnetic field generator outside of the patient. The patient is placed in the magnetic field created by the generator. As the LG is navigated through the airways, electrical current is induced in the coils and sent via conductors to a computer. The computer can calculate the position and orientation of the probe based on the relative strengths of the current being induced. This technology is shown and described in greater detail in U.S. Pat. Nos. 7,233,820 8,228,543, 8,188,355, 8,380,732, 8,593,884, 8,711,429, 8,558,333, 8,887,238, 8,615,155, 6,574,498, 8,947,768, 6,996,430, 6,702,780, and 8,833,814; and U.S. Patent Publications 20050171508, 20030074011, 20020193086, each of which is incorporated by reference herein in its entirety and also PCT application WO 03/086498 titled “Endoscope Structure and Techniques for Navigation in Branched Structure” to Gilboa, fully incorporated herein by reference. 
         [0004]    One type of tool used with the above-described system is a biopsy tool. Biopsy tools are designed to remove and retrieve small tissue samples from a suspected lesion for analysis and identification in a laboratory. Several factors are considered when taking biopsies of tissue such as biopsy location, biopsy size, and the number of samples needed from a suspected lesion. 
         [0005]    The above system and apparatus are aimed at the first consideration, target location, and provide a system that enables a physician to navigate standard bronchoscope tools, such as biopsy tools, to a target located in the lung. In its basic operation, the target is first identified in the CT data, and then the locatable guide is navigated to the target. The locatable guide is then removed from a sheath surrounding the LG and the sheath is then used as an extended working channel (“EWC”) through which a biopsy tool may be passed to the target location. 
         [0006]    Once the LG is removed, however, the locating system is no longer useful in identifying the location of the tip of the EWC. Hence, with regard to the biopsy tool, the physician is effectively “operating in the blind.” Additionally, quite often it is desired to take multiple samples from various locations within a lesion so as to ensure a representative sampling of tissue. 
         [0007]    It would be therefore advantageous to develop biopsy tools that have improved capabilities that address these identified needs. Namely, it would be advantageous to develop a biopsy, or tissue treatment tool that retrieves biopsy samples from or otherwise treats tissue in a variety of locations within a lesion simultaneously. It would also be advantageous to develop a biopsy tool that retrieves an adequate tissue sampling without requiring the removal of the LG from the EWC. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention represents a step forward in endoscopic biopsy and treatment procedures by providing tools designed for use with a three-dimensional locating system. The tools of the present invention are constructed to obviate the need for multiple navigation steps when taking one or more samples from a biopsy site, or performing one or more treatment procedures. 
         [0009]    One aspect of the present invention provides a tool that attaches to the end of an LG. Such a device provides many advantages. First, a small, attachable tool presents a cost savings when compared to a more traditional tool long enough to be routed through a catheter. Typically, LGs and biopsy tools are single-use disposable devices. Reducing the material and complexity of a disposable is always preferred in order to reduce costs. Second, because the attachable tool is attached to the LG, the LG maintains its functionality and, therefore, can be used to monitor the location of the tool throughout a procedure. Moreover, the beatable tool may be used to take samples from or treat tissue in multiple locations in a lesion without refracting the tool and repositioning the EWC. Also, because the tool is not removed from the lungs between samples, a single tool may be used. Third, input from the LG may be used to map and display the places in the lesion where samples have bean taken. 
         [0010]    Another aspect of the present invention provides a biopsy tool that includes multiple extensions that radiate from its distal tip when deployed. These extensions are designed to take individual samples from multiple locations in a target site simultaneously. This device may be used in the EWC after the LG is removed, as the multiple extensions effectively biopsy an entire lesion simultaneously, thereby reducing the need for location and tracking during the biopsy. Alternatively, this “flowering” biopsy tool may be incorporated into an LG, such that the LG does not need to be removed from the EWC prior to deployment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]      FIG. 1  is a perspective view of an embodiment of a device of the present invention; 
           [0012]      FIG. 2  is a perspective view of another embodiment of a device of the present invention; 
           [0013]      FIG. 3  is a perspective view of an embodiment of a device of the present invention; 
           [0014]      FIG. 4  is a perspective view of an embodiment of a device of the present invention; and, 
           [0015]      FIG. 5  is a perspective view of an embodiment of a device of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    Referring now to  FIG. 1 , there is shown an embodiment of a device  10  of the present invention. The device  10  generally comprises a delivery catheter or EWC  12 , an LG  14 , and an attachable tool  18 . The tool  16  is shown as a brush, but may be take any form of any device. In this sense,  FIG. 1  is showing the general concept of an attachable tool  16 , as well as providing a specific embodiment of a tool, in this case, a biopsy brush. Addressing the specific embodiment of a brush, the bristles of brush  18  may be configured with barbs or other tissue snagging devices if it is desired to increase the amount of tissue retrieved by the device  10 . 
         [0017]    Referring to the general embodiment of a generic tool, tool  16  has a proximal attachment portion  17  that is attachable to, or configured to mate with, the distal end  15  of the LG  14  by an end user, such as a physician or physician&#39;s assistant. In preferred embodiments, the attachment portion  17  includes a proximal skirt  18  that is sized to fit over the distal end  15  of the LG  14 . If it is desired to create a permanent attachment between the tool  16  and the LG  14 , an appropriate adhesive may be used to affix the tool  16  to the LG  14 . Alternatively, the distal end  15  of the LG may be configured to removably mate with the tool  16 . For example, distal end  15  may include a snap connector, a threaded connector, a luer lock, etc. Similarly, the skirt  18  may be configured appropriately to accept whatever configuration is formed on the distal tip  15  of the LG  14 . As shown, the distal tip  15  serves as a male component while the skirt  18  serves as a female component. One skilled in the art will understand that the distal tip  15  of the LG  14  may be configured as a female component for accepting a corresponding male component of the biopsy tool  16 . 
         [0018]    In a preferred embodiment, the LG  14  is a standard LG and the tool  16  is available in a variety of forms. Hence, a physician is able to attach any of several tools  16  to the distal end  15  of a standard LG  14  using either a permanent or removable adhesive. Each of the various embodiments of tools described herein generally include a tool portion and an attachment portion. In the example shown in  FIG. 1 , the tool  16  has an attachment portion  17 , described above as a proximal skirt  18 , and a tool portion  19 , in this case a biopsy brush. 
         [0019]    Another preferred embodiment of a device  20  is shown in  FIG. 2 . Like the device  10  of  FIG. 1 , the device  20  is deliverable through a catheter or EWC  12 . The device  20  further includes a biopsy tool  24  that radiates out of a sheath  22  when the tool  24  is advanced through the sheath  22 . This biopsy tool  24  allows several samples to be taken simultaneously, covering a relatively large area. The biopsy tool  24  includes a plurality of tines  28 , each of which is shown in the figure as being equipped with a barb for catching tissue. 
         [0020]    It is envisioned that the sheath  22  may comprise an LG that has been modified to include a lumen for accommodating the biopsy tool  24 . The device  20  is designed such that, after the tissue samples are taken, the biopsy tool is partially retracted into the sheath  22  until the tines  24  are brought together. The tines  24  and the sheath  22  may then be retracted into the EWC  12 . Leaving the tines  24  partially extended prevents the loss of the tissue samples taken. 
         [0021]      FIGS. 3-5  show various embodiments of tools according to the present invention. It is understood that all of these tools are attachable to the distal end of an LG in any of the various manners described above. 
         [0022]    Referring first to  FIG. 3 , there is shown a biopsy needle  30  according to the present invention. Biopsy needle  30  includes a scalloping blade  32  on a side surface of the needle  30 . The scalloping blade allows a relatively, large sample of tissue to be excised without the need for a jaw mechanism. The needle  30  also includes a hollow interior cavity  34  for receiving the tissue sample. In operation, the needle  30  is advanced into the target tissue and rotated. During rotation, the scallop blade  32  cuts a tissue sample and directs the sample into the cavity  34 . Upon retraction, any remaining connection to the tissue is severed by a distal edge of the blade  32 . Advantageously, little damage is done to any tissue that may lie between the targeted area, and the body lumen through which the LG was navigated to the site. Similarly, none of this tissue is sampled, as may be the case when using a brush device. Because the needle is rigid, the needle itself may easily be displayed using the navigation system, as the spatial relationship between the needle and the LG sensor is fixed. 
         [0023]      FIG. 4  shows a seed implantation fool  40 , including a seed  42  and a detachable coupling  44 . The detachable coupling allows the marker seed  42  to be detached from the distal end of the LG once the marker seed  42  is inserted into a target location. The detachable coupling may be electrolytic, dissolvable, meltable, threaded, shaped-memory metal, stress-induced martensite, or any other known detachment mechanism used in percutaneously-delivered devices. The seed  42  may be a marker seed or a therapeutic seed. Many seeds acceptable for this purpose are shown and described in U.S. Publication 2009/0240140 entitled “Target Identification Tool for intra-Body Localization” the entirety of which is incorporated by reference herein. Non-limiting examples include seeds adapted for use in marking locations, locatable visually or using ultrasound, Geiger meters, radio receivers, fluoroscopes, etc; or therapeutic seeds designed to administer drugs, chemotherapy, radiation therapy, cryo-therapy, ablation energy, or the like. 
         [0024]      FIG. 5  shows a biopsy needle  50  according to the present invention. Biopsy needle  50  includes a scalloping blade  52  on a side surface of the needle  50 , oriented so the blade faces a proximal direction. The scalloping blade allows a relatively large sample of tissue to be excised without the need for a jaw mechanism. The needle  50  also includes a hollow interior cavity  54  for receiving the tissue sample. In operation, the needle  50  is advanced into the target tissue and retracted. During retraction, the scallop blade  52  cuts a tissue sample and directs the sample info the cavity  54 . An air escape port  56  near a distal end of the needle  50  allows air or fluid to escape from the cavity  54 , to more easily allow tissue to fill the cavity. Because the needle is rigid, the needle itself may easily be displayed using the navigation system, as the spatial relationship between the needle and the LG sensor is fixed.  FIG. 5  is oriented to show the attachment portion  58 . It is understood that the attachment portion  58  of  FIG. 5  is representative of an attachment portion usable with any of the embodiments described herein. The attachment portion  58  includes a skirt  60  defining a female receptacle  62 . The skirt  60 , in this embodiment is shown with an interior surface containing threads  64 . As state above, the threads may be replaced with any appropriate fastening device, including, but not limited to, luer lock, snap fit, friction fit, etc., and may be supplemented with an adhesive. It is also envisioned that the device  50  of the present invention may be designed to take tissue samples at the distal end of the device. As shown, the device includes a distal tip shaped like a scoop. An opening (not shown) to the cavity  54  could be provided. In this case, the scallop blade  52  would be omitted and the air escape port  56  would be located in a proximal location. 
         [0025]    Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.