Abstract:
Methods and devices for visualizing and accessing a region inside a body are described. One embodiment of a device includes a working catheter which slides along an open track in a visualization catheter. The visualization catheter is inserted into the body to locate a region of the body with the aid of the visualization element. The working catheter then slides along the track to reach the region, and a working element is inserted through the working catheter to access the region, again with the aid of the visualization element. The methods and devices may also be used to access a variety of internal cavities, soft tissues and organs, and the mediastinal space.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/159,295, filed Jun. 13, 2011, which is a continuation-in-part of U.S. patent application Ser. No. 12/902,131, filed Oct. 11, 2010. The applications listed above are hereby incorporated by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    The pericardium is a tough, fibrous sac which surrounds and protects the heart. The pericardial space is formed between the two layers of the pericardium, the parietal pericardium and the serous pericardium. The serous pericardium has two layers, the first a fibrous layer and the second the epicardium which is closest to the heart. Pericardial fluid within the pericardial space serves to lubricate the motion of the heart. 
         [0003]    The pericardial space may be accessed to treat the heart for any one of a number of conditions. For example, the pericardial space may be accessed to perform epicardial ablations for the treatment of arrhythmias such as atrial fibrillation. The pericardial space may also be accessed to deliver drugs and stem cells for the treatment of heart attacks. 
         [0004]    The pericardial space may be accessed using minimally invasive techniques. One common technique involves guiding a needle to the pericardium, and then advancing the needle through the pericardium, all under fluoroscopy. However, because of anatomical variations and previous procedures, it may take up to an hour to navigate less than 10 cm through the body to locate a suitable area on the pericardium to create an access site. Navigating through the body with a sharp needle creates the risk of causing damage to structures such as the liver. During pericardial access, the risk posed by a sharp needle may cause damage to the underlying structures such as the coronary arteries and myocardium. 
         [0005]    The mediastinal space is the region between the two pleural sacs, with the sternum in front and the vertebral column behind. The mediastinal space can be an especially difficult area to access, especially in the area posterior of the heart, superior to the diaphragm, and inferior to the clavicle. 
         [0006]    What is needed are methods and devices which will reduce the amount of time needed to locate the pericardium and other regions inside the body, and reduce the risk of unintended puncture or damage to other structures during the location process. 
         [0007]    What is also needed are methods and devices which will facilitate the creation of an access site through the pericardium and other regions inside the body, while reducing the risk of damage or irritation to underlying structures. 
         [0008]    What is also needed are methods and devices which will facilitate access to the mediastinal space and other regions inside the body. 
       SUMMARY 
       [0009]    In one embodiment, an access device comprises a visualization catheter, a visualization element coupled to a distal end of the visualization catheter, and an open track formed along a length of the visualization catheter. The access device also comprises a working catheter configured to slide along the track until a distal end of the working catheter is in a vicinity of the visualization element, and a working lumen extending through the working catheter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIGS. 1A-1D  shows one embodiment of an access device  100 . 
           [0011]      FIGS. 2A-2F  show one method of using access device  100 . 
           [0012]      FIGS. 3A-3D  show another embodiment of an access device  200 . 
           [0013]      FIGS. 4A-4G  show one method of using access device  200 . 
           [0014]      FIGS. 5A-5D  show yet another embodiment of an access device  300 . 
           [0015]      FIGS. 6A-6G  and  7 A- 7 D show one method of using access device  300 . 
           [0016]      FIGS. 8A-8C  show other embodiments of a distal portion of access device  300 . 
           [0017]      FIGS. 9A-9D  show still another embodiment of an access device  400 . 
           [0018]      FIGS. 10A-10C  show another embodiment of an access device  500 . 
           [0019]      FIGS. 10D-10E  show alternative embodiments of access device  500 . 
           [0020]      FIGS. 11A-11H  show one method of using access device  500 . 
           [0021]      FIGS. 12A-12C  show another embodiment of an access device  600 . 
           [0022]      FIGS. 12D-12E  show alternative embodiments of access device  600 . 
           [0023]      FIGS. 13A-13H  show one method of using access device  600 . 
           [0024]      FIGS. 14A-14B  show one embodiment of an imaging package  700 . 
           [0025]      FIGS. 15A-15F  show one method of assembling imaging package  700 . 
       
    
    
     DETAILED DESCRIPTION 
       [0026]      FIGS. 1A-1B  show side views of one embodiment of an access device  100 .  FIG. 1C  shows an end view of access device  100 .  FIG. 1D  shows a cross-sectional end view of access device  100 . 
         [0027]    Access device  100  includes a handle  110 , a visualization catheter  130  with a visualization element  140 , and an access element  150 . 
         [0028]    Handle  110  includes a catheter lumen  114  and an access lumen  115 . Handle  110  may be constructed as two halves or as a clamshell. 
         [0029]    Visualization catheter  130  is at least partially positioned within catheter lumen  114 , and can slide and rotate within catheter lumen  114 . Visualization catheter  130  includes a proximal portion  131  and a distal portion  133 . Visualization catheter  130  may be a hollow tube made of a ductile material such as stainless steel or any other suitable material. Visualization catheter  130  includes a lumen  161 . Proximal portion  131  may be configured to facilitate rotation of visualization catheter  130  within catheter lumen  114 . Proximal portion  131  may be configured with an S-shaped bend to facilitate manipulation of visualization catheter  130 . Proximal portion  131  may include a coupling  134  for attachment of a power source and a video monitor. Distal portion  133  includes a visualization element  140  and one or more lights  141 . 
         [0030]    Visualization element  140  and lights  141  may be coupled to the tip or end of distal portion  133 . Alternatively, visualization element  140  and lights  141  may be coupled to the side or any other suitable location of distal portion  133 . Visualization element  140  and lights  141  are coupled to visualization wires  165  and light wires  166  which pass through lumen  161  to coupling  134 . Visualization element  140  and lights  141  are covered by a lens  142 . Lens  142  may have a hydrophobic coating or other coating to reduce adhesion of natural and synthetic materials that would obscure the image. As shown in  FIG. 1B , distal portion  133  may have a curved configuration, and may be bent or otherwise configured by the user and hold its shape. 
         [0031]    Access element  150  is at least partially positioned within access lumen  115 , and can slide and rotate within access lumen  115 . Access element  150  may be used for injection of a liquid, passing of a guidewire  105 , application of a vacuum, or any other suitable purpose. Access element  150  includes a proximal portion  151  and a distal portion  153 . Proximal portion  151  may include a coupling  154 . Distal portion  253  has a tip  255  that may be a blunt tip trocar, a blunt tip obturator, a sharp edge trocar, a sharp edge needle (e.g., Tuohy, epidural, biopsy), a guidewire tip, or any other suitable instrument. Access element  150  may be configured to work with an RF, microwave, cryoablation, high intensity focused ultrasound (HIFU), laser, or any other suitable energy source. Distal portion  153  may have depth markings. Distal portion  153  may be connected to an ohmmeter to measure impedance as the needle penetrates the pericardial membrane into the pericardial space. The impedance measurement may be used to provide an indication as to whether the pericardial membrane has been penetrated. As shown in  FIG. 1B , distal portion  153  may have a curved configuration, and may be bent or otherwise configured by the user and hold its shape. 
         [0032]      FIGS. 2A-2F  show one method of using access device  100 . 
         [0033]      FIG. 2A  shows a percutaneous puncture being made for a subxiphoid approach. Alternatively, an intercostal, apical, subclavian, suprasternal, or any other suitable approach may be used. 
         [0034]      FIG. 2B  shows visualization catheter  130  and access element  150  inserted through the puncture and positioned at or near the surface of the pericardium P. Visualization element  140  is used to guide visualization catheter  130  and access element  150  along the posterior aspect of the sternum S to the surface of the pericardium P. Visualization catheter  130  may be rotated and moved in and out. 
         [0035]      FIG. 2C  shows access element  150  advanced through pericardium P to create an access site. For an access element  150  having a sharp tip  155 , visualization element  140  may be used to visualize access element  150  as it is advanced through pericardium P. For an access element  150  used with RF energy, visualization element  140  may be used to visualize access element  150  as RF energy is passed through access element  150  to penetrate pericardium P. Access element  150  may be rotated so that a desired surface is visible to visualization element  140 . Saline, contrast, medications, and/or other fluids may be introduced through access element  150  into the pericardial space. 
         [0036]      FIG. 2D  shows guidewire  105  passed through access element  150  and positioned in the pericardial space. 
         [0037]      FIG. 2E  shows visualization catheter  130  and access element  150  withdrawn, leaving guidewire  105  in place. 
         [0038]      FIG. 2F  shows a sheath  180  advanced over guidewire  105  through the puncture and the access site and into the pericardial space. Other devices or guidewires may be advanced through sheath  180  to access the pericardial space. Saline, contrast, medications, and/or other fluids may be introduced through sheath  180  into the pericardial space. 
         [0039]      FIGS. 3A-3B  show side views of another embodiment of an access device  200 .  FIG. 3C  shows an end view of access device  200 .  FIG. 3D  shows a cross-sectional end view of access device  200 . 
         [0040]    Access device  200  includes a housing  210 , a visualization element  240 , and an access element  250 . 
         [0041]    Housing  210  includes a handle  211 , a central portion  212 , and a deflectable portion  213 . Housing  210  also includes an access lumen  215  and a visualization lumen  261 . Handle  211  includes a steering control  216 , a tension lock  217 , a visualization control  218 , and a light control  219 . Handle  211  may also include a coupling  234  for attachment of a power source and a video monitor. Central portion  212  is coupled to handle  211 , and is configured to be inserted into a puncture and navigate inside the body. Central portion  212  may be soft and flexible, or more rigid depending on the application and user preferences. Central portion  212  and/or deflectable portion  213  may have a cross-section that has a keyhole shape or any other suitable shape. 
         [0042]    Deflectable portion  213  is coupled to central portion  212  and is also configured to be inserted into a puncture and navigate inside the body. Deflectable portion  213  may be deflected in one or more axes, as shown for example in  FIG. 3B . Deflectable portion  213  may be controlled with pullwires  267  coupled to steering control  216 . Deflectable portion  213  may be locked in a desired configuration using tension lock  217 . Deflectable portion  213  includes a visualization element  240  and one or more lights  241 . 
         [0043]    Visualization element  240  and lights  241  may be coupled to a distal end  233  of deflectable portion  213 . Alternatively, visualization element  240  and lights  241  may be coupled to the side or any other suitable location of deflectable portion  213 . Visualization element  240  and lights  241  are coupled to visualization wires  265  and light wires  266  which pass through visualization lumen  261  to coupling  234 . Visualization element  240  and lights  241  are covered by a lens  242 . Lens  142  may have a hydrophobic coating or other coating to reduce adhesion of natural and synthetic materials that would obscure the image. Visualization element  240  may be turned on or off, or capture turned on or off using visualization control  218 . Lights  241  may be turned on or off, or their intensity adjusted using light control  219 . 
         [0044]    Access element  250  is at least partially positioned within access lumen  215 , and can slide and rotate within access lumen  215 . Access element  250  may be used for injection of a liquid, passing of a guidewire  205 , application of a vacuum, or any other suitable purpose. Access element  250  includes a proximal portion  251  and a distal portion  253 . Proximal portion  251  may include a coupling  254 . Distal portion  253  has a tip  255  that may be a blunt tip trocar, a blunt tip obturator, a sharp edge trocar, a sharp edge needle (e.g., Tuohy, epidural, biopsy), a guidewire tip, or any other suitable instrument. Access element  250  may be configured to work with an RF, microwave, cryoablation, high intensity focused ultrasound (HIFU), laser, or any other suitable energy source. Distal portion  253  may have depth markings. Distal portion  253  may be connected to an ohmmeter to measure impedance as the needle penetrates the pericardial membrane into the pericardial space. The impedance measurement may be used to provide an indication as to whether the pericardial membrane has been penetrated. Access element  250  may be moved and rotated by manipulating proximal portion  251 . 
         [0045]      FIGS. 4A-4G  show one method of using access device  200 . 
         [0046]      FIG. 4A  shows a percutaneous puncture being made for a subxiphoid approach. Alternatively, an intercostal, apical, subclavian, suprasternal, or any other suitable approach may be used. 
         [0047]      FIG. 4B  shows a dilator  203  inserted through the puncture. Dilator  203  is used to dilate the puncture and then withdrawn. 
         [0048]      FIG. 4C  shows central portion  212  and deflectable portion  213  inserted through the puncture and positioned at or near the surface of the pericardium P. Visualization element  240  is used to guide central portion  212  and deflectable portion  213  along the posterior aspect of the sternum S to the surface of the pericardium P. Deflectable portion  213  may be manipulated using steering control  216 . Access element  250  is retracted within distal end  233  of deflectable portion  213 . 
         [0049]      FIG. 4D  shows access element  250  extended from distal end  233  of deflectable portion  213 , and advanced through the pericardium P to create an access site. For an access element  250  having a sharp tip  255 , visualization element  240  is used to visualize access element  250  as it is advanced through pericardium P. For an access element  250  used with RF energy, visualization element  240  is used to visualize access element  250  as RF energy is passed through access element  250  to penetrate pericardium P. Access element  250  may be rotated so that a desired surface is visible to visualization element  240 . Saline, contrast, medications, and/or other fluids may be introduced through access element  250  into the pericardial space. 
         [0050]      FIG. 4E  shows guidewire  205  passed through access element  250  and positioned in the pericardial space. 
         [0051]      FIG. 4F  shows access element  250  retracted back into distal end  233  of deflectable portion  213 , and central portion  212  and deflectable portion  213  withdrawn, leaving guidewire  205  in place. 
         [0052]      FIG. 4G  shows a sheath  280  advanced over guidewire  205  through the puncture and the access site and into the pericardial space. Other devices or guidewires may be advanced through sheath  280  to access the pericardial space. Saline, contrast, medications, and/or other fluids may be introduced through sheath  280  into the pericardial space. 
         [0053]      FIGS. 5A-5B  show side views of yet another embodiment of an access device  300 .  FIG. 5C  shows an end view of access device  300 .  FIG. 5D  shows a cross-sectional end view of access device  300 . 
         [0054]    Access device  300  includes a housing  310 , a visualization element  340 , and an access element  350 . Access device  300  may also include a sheath  380 . 
         [0055]    Housing  310  includes a handle  311 , a central portion  312 , and a distal portion  313 A. Housing  310  also includes an access lumen  315  and a visualization lumen  361 . Handle  311  includes a visualization control  318  and a light control  319 . Handle  311  may also include a coupling  334  for attachment of a power source and a video monitor. Central portion  312  is coupled to handle  311 , and is configured to be inserted into a puncture and navigate inside the body. Central portion  312  may be substantially rigid. 
         [0056]    Distal portion  313 A is coupled to central portion  312  and is also configured to be inserted into a puncture and navigate inside the body. Distal portion  313 A may also be substantially rigid. Distal portion  313 A may have a curved configuration, and may be bent or otherwise configured by the user and hold its shape. Distal portion  313 A may include tubing made of a ductile material such as stainless steel or any other suitable material. Distal portion  313 A includes a visualization element  340  and one or more lights  341 . 
         [0057]    Visualization element  340  and lights  341  may be coupled to a distal end  333  of distal portion  313 A. Alternatively, visualization element  340  and lights  341  may be coupled to the side or any other suitable location of distal portion  313 A. Visualization element  340  and lights  341  are coupled to visualization wires  365  and light wires  366  which pass through visualization lumen  361  to coupling  334 . Visualization element  340 , lights  341 , and access lumen  315  are covered by a lens  342 . Lens  342  includes an opening  343  which is continuous with access lumen  315 . Lens  342  may also include a nozzle or other opening configured to clean lens  342 . Lens  342  may have a hydrophobic coating or other coating to reduce adhesion of natural and synthetic materials that would obscure the image. Visualization element  340  may be turned on or off, or capture pictures or video using visualization control  318 . Lights  341  may be turned on or off, or their intensity adjusted using light control  319 . 
         [0058]    Access element  350  is at least partially positioned within access lumen  315 , and can slide and rotate within access lumen  315 . Access element  350  may be used for injection of a liquid, passing of a guidewire  305 , application of a vacuum, or any other suitable purpose. Access element  350  includes a proximal portion  351 , a central portion  352 , and a distal portion  353 . Proximal portion  351  may include a coupling  354 . Distal portion  353  has a tip  355  that may be a blunt tip trocar, a blunt tip obturator, a sharp edge trocar, a sharp edge needle (e.g., Tuohy, epidural, biopsy), a guidewire tip, or any other suitable instrument. Access element  350  may be configured to work with an RF, microwave, cryoablation, high intensity focused ultrasound (HIFU), laser, or any other suitable energy source. Distal portion  353  may have depth markings. Distal portion  353  may be connected to an ohmmeter to measure impedance as the needle penetrates the pericardial membrane into the pericardial space. The impedance measurement may be used to provide an indication as to whether the pericardial membrane has been penetrated. Access element  350  may be moved and rotated by manipulating proximal portion  351 . 
         [0059]    Central portion  352  is flexible, and capable of translating motions from proximal portion  351  to distal portion  353 . Flexible central portion  352  allows access element  350  to move with distal portion  313 A of housing  310 . Central portion  352  may be constructed of a flexible braided material, a ductile metal, or any other suitable material. Proximal portion  351  may be substantially rigid. Distal portion  353  may be substantially rigid to facilitate penetration of tissue. Proximal portion  351 , central portion  352 , and distal portion  353  may be coupled with any suitable coupling device or method. 
         [0060]    Sheath  380  includes a proximal portion  381 , a central portion  382 , and a distal portion  383 . Proximal portion  381  may be grasped, and may include a coupling for attachment to an RF or other suitable energy source. Distal portion  383  may be made of a soft, flexible material and may stretch to fit snugly around housing  310 . Central portion  382  may include electrodes  385  for coagulation and other purposes. Central portion  382  may have electrodes  385  that are configured circumferentially. Alternatively, electrodes  385  may be configured in a spiral, double helix, opposing helix, or any other suitable configuration. Electrodes  385  may be embedded in central portion  382  or otherwise coupled to central portion  382  in any suitable manner. 
         [0061]    Sheath  380  may have a distal portion  383  that is tapered, with smaller end that tapers up in size towards central portion  382 . The smaller end facilitates insertion of distal portion  383  into a puncture. The taper allows distal portion  383  to dilate the puncture as it is advanced. Electrodes  385  are configured to control bleeding proximate to the sheath at the site of the puncture, pericardium, or other structures. 
         [0062]      FIGS. 6A-6G  show one method of using access device  300 . 
         [0063]      FIG. 6A  shows a percutaneous puncture being made for a subxiphoid approach. Alternatively, an intercostal, apical, subclavian, suprasternal, or any other suitable approach may be used. 
         [0064]      FIG. 6B  shows a dilator  303  inserted through the puncture. Dilator  303  is used to dilate the puncture and then withdrawn. 
         [0065]      FIG. 6C  shows central portion  312  and distal portion  313 A inserted through the puncture and positioned at or near the surface of the pericardium P. Visualization element  340  is used to guide central portion  312  and distal portion  313 A along the posterior aspect of the sternum S to the surface of the pericardium P. Access element  350  is retracted within distal end  333  of distal portion  313 A. 
         [0066]      FIG. 6D  shows access element  350  extended from distal end  333  of distal portion  313 A, and advanced through the pericardium P to create an access site. For an access element  350  having a needle tip  355 , visualization element  340  is used to visualize access element  350  as it is advanced through pericardium P. For an access element  350  used with RF energy, visualization element  340  is used to visualize access element  350  as RF energy is passed through access element  350  to penetrate pericardium P. Access element  350  may be rotated so that a desired surface is visible to visualization element  340 . Saline, contrast, medications, and/or other fluids may be introduced through access element  350  into the pericardial space. 
         [0067]      FIG. 6E  shows guidewire  305  advanced through access element  350  and positioned in the pericardial space. 
         [0068]      FIG. 6F  shows access element  350  retracted back into distal end  333  of distal portion  313 A, and central portion  312  and distal portion  313 A withdrawn, leaving guidewire  305  in place. 
         [0069]      FIG. 6G  shows sheath  380  advanced over guidewire  305  through the puncture and the access site and into the pericardial space. Electrodes  385  may be used for coagulation. Other devices or guidewires may be advanced through sheath  380  to access the pericardial space. Saline, contrast, medications, and/or other fluids may be introduced through sheath  380  into the pericardial space. 
         [0070]      FIGS. 7A-7D  show enlarged cross-sectional side views of distal portion  313 A.  FIG. 7A  shows distal portion  313 A with tip  355  of access element  350  retracted inside distal end  333 .  FIG. 7B  shows distal portion  313 A with tip  355  of access element  350  extended from distal end  333 .  FIG. 7C  shows guidewire  305  advanced through access element  350 .  FIG. 7D  shows tip of  355  of access element  350  pulled back inside distal end  333 . Guidewire  305  remains in place. 
         [0071]      FIGS. 8A-8C  show other embodiments of distal end  333  of distal portion  313 A.  FIG. 8A  shows another embodiment of distal end  333  with lens  342  having a tapered profile. The tapered profile of distal end  333  may facilitate its advancement into the pericardial space.  FIG. 8B  shows yet another embodiment of distal end  333  having an asymmetrical tapered profile. Visualization element  340  and lights  341  may be mounted on the underside of the taper facing access element  350 . The tapered profile of distal end  333  may facilitate its advancement into the pericardial space.  FIG. 8C  shows still another embodiment of distal end  333  with a visualization element  340  mounted on guidewire  305  and positioned within access element  350 . Visualization element  340  is capable of being moved independently of access element  350 . 
         [0072]      FIGS. 9A-9B  show side views of still another embodiment of access device  400 .  FIG. 9C  shows an end view of access device  400 .  FIG. 9D  shows a cross-sectional end view of access device  400 . 
         [0073]    Access device  400  includes a housing  310 , a visualization element  340 , and an access element  350 . Access device  400  may also include a sheath  380 . 
         [0074]    Housing  310  includes a handle  311 , a central portion  312 , and a deflectable portion  313 B. Housing  310  also includes an access lumen  315  and a visualization lumen  361 . Handle  311  includes a steering control  316 , a tension lock  317 , a visualization control  318 , and a light control  319 . Handle  211  may also include a coupling  334  for attachment of a power source and a video monitor. Central portion  312  is coupled to handle  311 , and is configured to be inserted into a puncture and navigate inside the body. Central portion  312  may be soft and flexible, or more rigid depending on the application and user preferences. 
         [0075]    Deflectable portion  313 B is coupled to central portion  312  and is also configured to be inserted into a puncture and navigate inside the body. Deflectable portion  313 B may be deflected in one or more axes, as shown for example in  FIG. 5B . Deflectable portion  313 B may be controlled with pullwires  367  coupled to steering control  316 . Deflectable portion  313 B may be locked in a desired configuration using tension lock  317 . Deflectable portion  313 B includes a visualization element  340  and one or more lights  341 . 
         [0076]    Access device  400  is similar to access device  300 , but instead of a distal portion  313 A that may be bent or otherwise configured by the user before being introduced into the body, access device  400  includes a deflectable portion  313 B that is controlled by pullwires  367  coupled to steering control  316  and tension lock  317 . The remainder of access device  400  is similar to access device  300 . Access device  400  may be used in a manner similar to access device  300 . 
         [0077]    Access device  400  may have a central portion  312  that is lengthened. Access device  400  with a lengthened central portion  312  may be used to visualize and treat structures in the mediastinal space outside of the pericardium. Access device  400  with a lengthened central portion  312  may used to first create an entry site through the pericardium and introduce guidewire  305  into the pericardial space. Deflectable portion  313 B may then be advanced over guidewire  305  through the entry site and into the pericardial space. Deflectable portion  313 B may then be steered and navigated within the pericardial space to find a desired exit site. Deflectable portion  313 B may then be used to create an exit site through the pericardium and access structures in the mediastinal space outside of the pericardium. Structures located posterior of the heart, superior to the diaphragm, and inferior to the clavicle such as the esophagus, trachea, primary bronchi, posterior pleural cavities, thoracic vertebrae and other structures may thus be accessed for delivery of therapeutics, biopsy, fixation, ablation, survey, and other purposes. 
         [0078]      FIGS. 10A-10B  show side and exploded views of one embodiment of an access device  500 .  FIG. 10C  shows a cross-sectional view of access device  500 .  FIGS. 10D-10E  show cross-sectional views of alternative embodiments of access device  500 . 
         [0079]    Access device  500  includes a visualization catheter  530  with a track  535 , a working catheter  520 , and a visualization element  540 . 
         [0080]    Visualization catheter  530  is configured to be inserted through a percutaneous puncture and navigate inside a body. Visualization catheter  530  may be rigid or flexible. Visualization catheter  530  may be straight or curved, or may be bent or otherwise configured by a user and hold its shape. Visualization catheter  530  includes a track  535  formed along its length. Track  535  is open to an exterior of visualization catheter  530 . 
         [0081]    Working catheter  520  is configured to slide along track  535 . Working catheter  520  includes a working lumen  524  which allows a working element  550  to insert through. Working catheter  520  may be made of plastic, fabric, or any other suitable material. 
         [0082]    As shown in  FIG. 10C , working catheter  520  may have a cross section that is substantially circular, and track  535  may have a cross section that is substantially semicircular and receives working catheter  520 . Alternatively, as shown in  FIGS. 10D-10E , working catheter  520  may include a runner  525  that is configured to slide at least partially within track  535 . Runner  525  may extend along the length of working catheter  520 , or only along a portion of working catheter  520 , such as at a distal end  523  of working catheter  520 . Runner  525  and track  535  may be any suitable shape.  FIG. 10D  shows a working catheter  520  with a runner  525  that is substantially circular, and a track  535  that is also substantially circular.  FIG. 10E  shows a working catheter  520  with a runner  525  that is T-shaped, and a track  535  that is also T-shaped. 
         [0083]    Track  535  may have a stop at a distal end  533  of visualization catheter  530  which prevents distal end  523  of working catheter  520  from traveling beyond distal end  533  of visualization catheter  530 . 
         [0084]    Visualization element  540  and one or more illumination elements  541  may be coupled to a distal end  533  of visualization catheter  530 . Alternatively, visualization element  540  and illumination elements  541  may be coupled to the side or any other suitable location of visualization catheter  530 , or mounted at a suitable angle to improve visualization. Visualization element  540  may include an imaging element with a pinhole aperture and/or one or more lenses. Visualization element  540  and illumination elements  541  may be covered by a cover  542 . Cover  542  may include a nozzle or other opening configured to clean cover  542 . Cover  542  may have a hydrophilic coating, a hydrophobic coating, or other coating to reduce adhesion of natural and synthetic materials that would obscure the image. Visualization element  540  may have a focal length selected for use with a typical working distance of working element  550 , or be focused on an interior surface of cover  542 . 
         [0085]    A working element  550  may be inserted through working lumen  524  of working catheter  520 , and can slide and rotate within working lumen  24 . Working element  550  may be used for injection of a liquid, passing of a guidewire  505 , application of a vacuum, or any other suitable purpose. Working element  550  includes a proximal portion  551 , a central portion  552 , and a distal portion  553 . Proximal portion  551  may include a coupling  554 . Distal portion  553  has a tip  555  that may be a blunt tip trocar, a blunt tip obturator, a sharp edge trocar, a sharp edge needle (e.g., Tuohy, epidural, biopsy), a guidewire tip, or any other suitable instrument. Working element  550  may be configured to work with an RF, microwave, cryoablation, high intensity focused ultrasound (HIFU), laser, or any other suitable energy source. Distal portion  553  may have depth markings. Distal portion  553  may be connected to an ohmmeter to measure impedance as the needle penetrates the pericardial membrane into the pericardial space. The impedance measurement may be used to provide an indication as to whether the pericardial membrane has been penetrated. Working element  550  may be moved and rotated by manipulating proximal portion  551 . 
         [0086]    Visualization catheter  530  may include at its proximal end  531  a handle  510 . Handle  510  may include an opening  515  configured to receive working catheter  520 . Opening  515  aligns working catheter  520  with track  535 . Opening  515  may have a shape similar to a cross section of working catheter  520 . If working catheter  520  includes a runner  525 , opening  515  and may help “thread” runner  525  into track  535 . 
         [0087]    Working catheter  520  may be configured to fit loosely around working element  550 , or to reduce the amount of friction or drag on working element  550 . Working catheter  520  allows working element  550  to move freely within working lumen  524  and enhance the “feel” and control of position at a proximal portion  551  of working element  550  of what is being accessed at a distal portion  553  of working element  550 . Working catheter  520  may have a length substantially similar to that of visualization catheter  530 . 
         [0088]      FIGS. 11A-11H  show one method of using access device  500 . 
         [0089]      FIG. 11A  shows a percutaneous puncture being made for a subxiphoid approach. Alternatively, an intercostal, apical, subclavian, suprasternal, or any other suitable approach may be used. 
         [0090]      FIG. 11B  shows a dilator  503  inserted through the puncture. Dilator  503  is used to dilate the puncture and then withdrawn. 
         [0091]      FIG. 11C  shows visualization catheter  530  inserted through the puncture and its distal end  533  positioned at or near the surface of the pericardium P. Visualization element  540  is used to guide visualization catheter  530  along the posterior aspect of the sternum S to the surface of the pericardium P. 
         [0092]      FIG. 11D  shows working catheter  520  inserted through opening  515  in handle  510  and along track  535  through the puncture, until distal end  523  of working catheter  520  is in the vicinity of visualization element  540 . 
         [0093]      FIG. 11E  shows a working element  550  passed through working lumen  524  of working catheter  520 , and advanced through the pericardium P to create an access site. For a working element  550  having a needle tip  555 , visualization element  540  is used to visualize working element  550  as it is advanced through pericardium P. For a working element  550  used with RF energy, visualization element  540  is used to visualize working element  550  as RF energy is passed through working element  550  to penetrate pericardium P. Working element  550  may be rotated so that a desired surface is visible to visualization element  540 . Saline, contrast, medications, and/or other fluids may be introduced through working element  550  into the pericardial space. 
         [0094]      FIG. 11F  shows guidewire  505  advanced through working element  550  and positioned in the pericardial space. 
         [0095]      FIG. 11G  shows visualization catheter  530 , working catheter  520 , and working element  550  withdrawn, leaving guidewire  505  in place. 
         [0096]      FIG. 11H  shows a sheath  580  advanced over guidewire  505  through the puncture and the access site and into the pericardial space. Other devices or guidewires may be advanced through sheath  580  to access the pericardial space. Saline, contrast, medications, and/or other fluids may be introduced through sheath  580  into the pericardial space. 
         [0097]      FIGS. 12A-12B  show side views of another embodiment of an access device  600 .  FIG. 12C  shows an cross-sectional view of access device  600  at a break  620 .  FIGS. 12D-12E  show alternative embodiments of access device  600 . 
         [0098]    Access device  600  includes a catheter  610  having a proximal segment  611  and a distal segment  613  coupled by a joint  612 , and a visualization element  640 . 
         [0099]    Catheter  610  includes a proximal segment  611  and a distal segment  613 . A visualization lumen  661  extends continuously through proximal segment  611  and distal segment  613 . A distal working lumen  615  extends through distal segment  613 . Catheter  610  may include a coupling  634  for attachment of a power source, video monitor, and/or controls. 
         [0100]    Proximal segment  611  and distal segment  613  are coupled by a joint  612 . Joint  612  may be opened to provide access to distal working lumen  615  without breaking visualization lumen  661 . Joint  612  may be a cut or notch  612 A passing across distal working lumen  615  which does not impinge on visualization lumen  661 . Catheter  610  may be made of a material that is sufficiently flexible to allow catheter  610  to flex or bend at joint  612  and provide access to distal working lumen  615 . Catheter  610  may be able to bend as much as is necessary to allow access to distal working lumen  615 . Alternatively, joint  612  may be a hole or aperture formed in a side of catheter  610  which may be bent to provide access to distal working lumen  615 . A removable sleeve  617  may be used over joint  612  to prevent joint  612  from bending until needed. Alternatively, pullwires may be used to lock joint  612  in open and closed positions. Catheter  610  may include other lumens  662  such as irrigation and vacuum lumens which, like visualization lumen  661 , are not broken by joint  612 . 
         [0101]    Alternatively, joint  612  may be a hinge  612 B as shown in  FIG. 12D  which may be rotated to be opened, or a swivel  612 C as shown in  FIG. 12E  which may be rotated to open joint  612  and provide access to distal working lumen  615 . Catheter  610  with a hinge  612 B or a swivel  612 C may be made of a flexible or a rigid material. 
         [0102]    Distal segment  613  is configured to be inserted through a percutaneous puncture and navigate inside the body. Distal segment  613  may have a curved configuration, and may be bent or otherwise configured by the user and hold its shape. 
         [0103]    Visualization element  640  and one or more illumination elements  641  may be coupled to a distal end  633  of distal segment  613 . Alternatively, visualization element  640  and illumination elements  641  may be coupled to the side or any other suitable location of distal segment  613 , or mounted at a suitable angle to improve visualization. Visualization element  640  may include an imaging element with a pinhole aperture and/or one or more lenses. Visualization element  640 , illumination elements  641 , and distal working lumen  615  may be covered by a cover  642 . Cover  642  may include a channel  643  which is continuous with distal working lumen  615 . Alternatively, cover  642  may cover only visualization element  640  and illumination elements  641 , and not distal working lumen  615 . Cover  642  may include a nozzle or other opening configured to clean cover  642 . Cover  642  may have a hydrophilic coating, a hydrophobic coating, or other coating to reduce adhesion of natural and synthetic materials that would obscure the image. Visualization element  640  may have a focal length selected for use with a typical working distance of working element  650 , or be focused on an interior surface of cover  642 . 
         [0104]    A working element  650  may be inserted through distal working lumen  615 , and can slide and rotate within distal working lumen  615 . Working element  650  may be used for injection of a liquid, passing of a guidewire  605 , application of a vacuum, or any other suitable purpose. Working element  650  includes a proximal portion  651 , a central portion  652 , and a distal portion  653 . Proximal portion  651  may include a coupling  654 . Distal portion  653  has a tip  655  that may be a blunt tip trocar, a blunt tip obturator, a sharp edge trocar, a sharp edge needle (e.g., Tuohy, epidural, biopsy), a guidewire tip, or any other suitable instrument. Working element  650  may be configured to work with an RF, microwave, cryoablation, high intensity focused ultrasound (HIFU), laser, or any other suitable energy source. Distal portion  653  may have depth markings. Distal portion  653  may be connected to an ohmmeter to measure impedance as the needle penetrates the pericardial membrane into the pericardial space. The impedance measurement may be used to provide an indication as to whether the pericardial membrane has been penetrated. Working element  650  may be moved and rotated by manipulating proximal portion  651 . 
         [0105]    Joint  612  reduces the length of distal working lumen  615 . This enhances the “feel” and control of position at a proximal portion  651  of working element  650  of what is being accessed at a distal portion  653  of working element  650 . Also, a shorter distal working lumen  615  may allow a greater range of off-the-shelf needles to be used as working element  650 . A first user may manipulate working element  650 , while a second user may operate catheter  610  and visualization element  640  and other functions such as vacuum and irrigation. 
         [0106]    Alternatively, proximal segment  611  may include a proximal working lumen which aligns with distal working lumen  615  when joint  612  is closed, and catheter  610  may be used with a full-length working lumen. 
         [0107]      FIGS. 13A-13H  show one method of using access device  600 . 
         [0108]      FIG. 13A  shows a percutaneous puncture being made for a subxiphoid approach. Alternatively, an intercostal, apical, subclavian, suprasternal, or any other suitable approach may be used. 
         [0109]      FIG. 13B  shows a dilator  603  inserted through the puncture. Dilator  303  is used to dilate the puncture and then withdrawn. 
         [0110]      FIG. 13C  shows catheter  610  inserted through the puncture and distal end  633  of distal segment  613  positioned at or near the surface of the pericardium P. Visualization element  640  is used to guide distal segment  613  along the posterior aspect of the sternum S to the surface of the pericardium P. 
         [0111]      FIG. 13D  shows joint  612  opened to expose distal working lumen  615 . 
         [0112]      FIG. 13E  shows a working element  650  passed through distal working lumen  615 , and advanced through the pericardium P to create an access site. For a working element  650  having a needle tip  655 , visualization element  640  is used to visualize working element  650  as it is advanced through pericardium P. For a working element  650  used with RF energy, visualization element  640  is used to visualize working element  650  as RF energy is passed through working element  650  to penetrate pericardium P. Working element  650  may be rotated so that a desired surface is visible to visualization element  640 . Saline, contrast, medications, and/or other fluids may be introduced through working element  650  into the pericardial space. 
         [0113]      FIG. 13F  shows guidewire  605  advanced through working element  650  and positioned in the pericardial space. 
         [0114]      FIG. 13G  shows catheter  610  and working element  650  withdrawn, leaving guidewire  605  in place. 
         [0115]      FIG. 13H  shows a sheath  680  advanced over guidewire  605  through the puncture and the access site and into the pericardial space. Other devices or guidewires may be advanced through sheath  680  to access the pericardial space. Saline, contrast, medications, and/or other fluids may be introduced through sheath  680  into the pericardial space. 
         [0116]      FIGS. 14A-14B  show one embodiment of an imaging package  700 . Imaging package  700  includes a imaging element  710 , an alignment block  720 , wires  730 , and an adhesive  740 . 
         [0117]    Imaging element  710  includes an imaging chip  712  and an optical element  714 . Imaging chip  712  may be a CCD, CMOS, or any other suitable imaging device. Imaging chip  712  may be coupled to a printed circuit board having on its back surface solder pads  713 . Optical element  714  may be an infrared filter. Optical element  714  may also be a cover, a pinhole aperture, and/or one or more lenses. 
         [0118]    Alignment block  720  includes a plurality of holes  722  which are aligned with the solder pads  713  of imaging chip  712 . Alignment block  720  serves to facilitate the coupling of wires  730  to solder pads  713 . 
         [0119]      FIGS. 15A-15F  show one method of assembling imaging package  700 .  FIG. 15A  shows wires  730  passed through holes  722  of alignment block  720  so that wires  730  protrude from the other side of alignment block  720 .  FIG. 15B  shows an adhesive such as epoxy applied to the protruding wires  730 . Adhesive may also be applied to the insertion side.  FIG. 15C  shows the epoxy and protruding wires  730  machined or sanded down to a substantially smooth or even surface. Wires  730  protrude slightly from alignment block  720 .  FIG. 15D  shows a conductive material such as a soft solder applied to the back side of imaging element  710 .  FIG. 15E  shows imaging element  710  with the soft solder being brought into contact with the machined or sanded down surface of alignment block  720  and into contact with wires  730 .  FIG. 15F  shows an adhesive such as epoxy applied in between imaging element  710  and alignment block  720  to secure imaging element  710  to alignment block  720 . 
         [0120]    Visualization element  140 ,  240 ,  340 ,  540 , or  640  may include a CCD, CMOS, or any other suitable imaging device, such as those available Omnivision Technologies, Inc., Santa Clara, Calif. Alternatively, visualization element  140 ,  240 ,  340 ,  540 , or  640  may include a fiber optic device. Visualization element  140 ,  240 ,  340 ,  540 , or  640  may also be an IntroSpicio 120 CMOS camera, available from Medigus Ltd., Omer, Israel. 
         [0121]    Although the above embodiments and methods describe using the access device to visualize and access the pericardial space, this device may be used to visualize and access any space, tissue, or organ in the body. Examples include the heart, peritoneum, diaphragm, mediastinal structures, thoracic, liver, kidney, thoracic, and abdominal regions. 
         [0122]    While the foregoing has been with reference to particular embodiments of the invention, it will be appreciated by those skilled in the art that changes in these embodiments may be made without departing from the principles and spirit of the invention. 
         [0123]    All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.