Patent Publication Number: US-8535272-B2

Title: Sealing member for a catheter

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. application Ser. No. 12/476,539, filed Jun. 2, 2009, now U.S. Pat. No. 8,167,845, which is hereby incorporated by reference in its entirety as though fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The field of the invention relates generally to catheters and, more specifically, to catheters having seals located in a distal portion thereof that prevent fluid passage during a surgical procedure. 
     2. Background Art 
     During surgical procedures that utilize a catheter, controlling fluid passage through the catheter is important. It is particularly important when the catheter includes inner channels that extend the length of the catheter and have physical elements passing therethrough. For example, as illustrated in  FIG. 1 , a known basket electrode mapping catheter  100  includes a first inner tube or rod member  102  that passes through a second outer tubular member  104 . As basket electrode  106  is extended and retracted, relative movement occurs between members  102  and  104 . To allow such relative movement, a space or gap  108  exists between members  102  and member  104 . It is through spaces, such as gap  108 , that blood and other bodily fluids can flow  110  unless they are impeded. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one aspect, a catheter is provided that includes a proximal end, a distal end, a tubular member, and an inner member extending through the tubular member. The inner member is movable axially relative to the tubular member. The catheter also includes a seal member including a first portion and a second portion. The seal member extends between the tubular member and the inner member. The first portion of the seal member remains stationary relative to the tubular member, and the second portion of the seal member remains stationary relative to the inner member during relative axial movement between the tubular member and the inner member. 
     In another aspect, a basket electrode mapping catheter is provided that includes a proximal end, a distal end, a tubular member, an inner member extending through the tubular member, and a basket electrode connected to a distal end of the inner member. The catheter also includes a seal member having a first portion and a second portion. The seal member first portion contacts the tubular member. The seal member second portion contacts the inner member. The seal member is configured to prevent fluid flow between the tubular member and the inner member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a prior art basket electrode mapping catheter showing potential fluid ingress into the catheter. 
         FIG. 2  is a schematic view of a basket electrode mapping catheter in accordance with one embodiment of the invention. 
         FIG. 3  is a schematic view of the basket electrode shown in  FIG. 2  including a collar. 
         FIG. 3A  is an enlarged view of the collar shown in  FIG. 3 . 
         FIG. 4  is a cut-away view of a seal used in the catheter shown in  FIG. 2  with the inner member in an extended position. 
         FIG. 5  is a cut-away view of the seal shown in  FIG. 4  with the inner member in a retracted position. 
         FIG. 6  is a cut-away view of an alternative seal used in the catheter shown in  FIG. 2 . 
         FIG. 7  is a cut-away view of a further alternative seal used in the catheter shown in  FIG. 2 . 
         FIG. 8  is a cut-away view of a rolling seal used in the catheter shown in  FIG. 2 . 
         FIG. 9  is a cut-away view of an accordion seal used in the catheter shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention set forth below in detail is a sealed catheter having a mapping electrode assembly that is utilized, for example, in an electrophysiology procedure. In one embodiment, the catheter includes an inner member such as an inner tubular member, or a rod that moves axially with respect to an outer tubular member. The catheter also includes a seal that includes a portion that remains stationary relative to the inner member during at least a portion of the movement of the inner member. In addition, the seal includes a portion that remains relatively stationary with the outer tubular member during at least a portion of the movement of the inner member. 
     The systems and methods set forth below are not limited to the specific embodiments described herein. In addition, components of each system and steps of each method can be practiced independently and separately from other components and method steps described herein. Each component and method step also can be used in combination with other catheters, electrodes, systems, and methods. 
     As used herein, “proximal” refers to the direction away from the body of a patient and towards a clinician. Furthermore, as used herein, “distal” refers to the direction toward the body of a patient and away from the clinician. 
       FIG. 2  is a schematic view of a basket electrode mapping catheter  150  in accordance with one embodiment of the present invention. While  FIG. 2  is shown with a basket electrode mapping catheter, other mapping catheters are within the scope of this invention, including circular mapping catheters lariat designs, splines, and the like. Catheter  150  includes a distal end  152  and a proximal end  154 . An outer tubular member  156  extends from distal end  152  to proximal end  154 . An inner member  158  extends through outer tubular member  156  and is at least partially extendable beyond a distal end  160  of outer tubular member  156 . A basket electrode assembly  162  is connected to a distal end  164  of inner member  158 . In one embodiment, inner member  158  is a rod. In another embodiment, inner member  158  is a tubular member. Basket electrode assembly  162  includes a plurality of arms  166 , each including at least one electrode (not shown in  FIG. 2 ). A set of leads (not shown) extend from the electrodes through outer tubular member  156 . The leads extend from catheter proximal end  154  in a cable  168  that is connected to an EKG recording system, such as EP-Workmate® EP Lab Recording System, or EnSite® System. 
     Catheter  150  also includes a handle  172  at proximal end  154 . Handle  172  is utilized to manipulate catheter distal end  152 , and more specifically, basket electrode assembly  162 , during operation of catheter  150 . 
       FIG. 3  is a schematic view of basket electrode assembly  162  extended from outer tubular member  156 . Assembly  162  includes a plurality of electrode arms  166 , each including a plurality of electrodes  180 . Inner member  158  forms a central shaft through basket electrode assembly  162 . Assembly  162  includes a cap  182  at a distal tip  184  of inner member  158 . Cap  182  is utilized to contain distal ends  186  of arms  166  and is fabricated from a soft polymer such as polyurethane or silicone. Assembly  162  also includes a middle tubular member  188  positioned between outer tubular member  156  and inner member  158 . A collar  190  is used to attach proximal ends  192  of arms  166  to middle tubular member  188 . As shown in  FIG. 3A , proximal ends  192  of arms  166  pass through collar  190  and are attached to middle tubular member  188  by collar  190 . A set of wires  194  extends proximally from collar  190  and, in one embodiment, is connected to EKG recording system  170  (shown in  FIG. 2 ). 
       FIG. 3  also illustrates a seal member  200  attached to inner member  158  and middle tubular member  188 . Seal member  200  is configured to prevent fluid flow between inner member  158  and middle tubular member  188 , while still enabling relative axial movement between inner member  158  and middle tubular member  188 . In one embodiment, basket assembly  162  is extended from outer tubular member  156  through distal movement of both inner member  158  and middle tubular member  188 . Once inner member  158  has been extended the proper amount, middle tubular member  188  is further extended to bend electrode arms  166  and force them away from inner member  158  and into contact with an interior surface of a heart. Since inner members are formed from resilient material, they are able to apply varying forces to the heart tissue depending on the amount of distance between cap  182  and collar  190 . Catheter  150  can allow for unimpeded blood flow through the heart during the procedure while placing electrodes  180  into contact with a heart chamber wall for in-contact mapping of the physiologic potentials of the heart. In the alternative, catheter  150  can further include a balloon (not shown) to exclude blood flow between arms  166 . 
       FIGS. 4 and 5  are cut-away views of distal end  152  of catheter  150  including a seal member  200 .  FIGS. 4 and 5  are directed to seal member  200  that extends between middle tubular member  188  and inner member  158 . As such, some of the details of catheter  150  shown in  FIG. 3  have been removed for clarity. It should be understood, however, that  FIGS. 4 and 5  illustrate a specific aspect of catheter  150  shown in  FIG. 3 . 
     Seal member  200  includes an inner surface  202  and an outer surface  204 . In addition, seal member  200  includes a first portion  206  and a second portion  208 . Outer surface  204  of seal member first portion  206  contacts and is attached to an inner surface  210  of middle tubular member  188 , and inner surface  202  of seal member second portion  208  contacts and is attached to an outer surface  212  of inner member  158 . In one embodiment, portions  206  and  208  are attached to members  188  and  158 , respectively, with an adhesive. Alternatively, portions  206  and  208  are attached to members  188  and  158 , respectively, with a mechanical fastener. Seal member  200  is placed between the two catheter portions that must be sealed, e.g., between middle tubular member  188  and inner tubular member  158 , or between middle tubular member  188  and outer tubular member  156 . 
     As shown in  FIGS. 4 and 5 , seal member  200  is a tubular member that surrounds inner member  158  and is at least partially contained within middle tubular member  188 . During extension of inner member  158 , second portion  208  of seal member  200  moves distally with respect to first portion  206 .  FIG. 4  illustrates inner member  158  in a fully extended configuration and  FIG. 5  illustrates inner member  158  in a fully retracted configuration and shows seal member  200  folded upon itself. Seal member  200  is configured to prevent fluid ingress through the space between middle tubular member  188  and inner member  158  while allowing inner member  158  to move a sufficient amount so that basket electrode  162  (shown in  FIGS. 2 and 3 ) can be fully deployed during a procedure and fully retracted when not is use, or vice versa. In one embodiment, seal member  200  is fabricated from at least one of polyurethane, silicone, and any other suitable biocompatible material that is flexible and fluid impermeable. 
       FIGS. 6 and 7  are cut-away views of distal end  152  of catheter  150  including an alternative seal member  220 .  FIGS. 6 and 7  are directed to seal member  220  that extends between middle tubular member  188  and inner member  158 . As such, some of the details of catheter  150  shown in  FIG. 3  have been removed for clarity. It should be understood, however, that  FIGS. 6 and 7  illustrate an alternative aspect of catheter  150  shown in  FIG. 3 . 
     Seal member  220  extends between middle tubular member  188  and inner member  158 . Seal member  220  includes a first surface  222  and a second surface  224 . In addition, seal member  220  includes a first portion  226  and a second portion  228 . First surface  222  of seal member first portion  226  contacts and is attached to an inner surface  230  of middle tubular member  188 . First surface  222  of seal member second portion  228  also contacts and is attached to an outer surface  232  of inner member  158 . In one embodiment, portions  226  and  228  are attached to members  188  and  158 , respectively, with an adhesive. Alternatively, portions  226  and  228  are attached to members  188  and  158 , respectively, with a mechanical fastener. 
     As shown in  FIGS. 6 and 7 , seal member  220  is a tubular member that surrounds inner member  158  and is at least partially contained within middle tubular member  188 . During extension of inner member  158 , second portion  228  of seal member  220  moves distally with respect to first portion  226 .  FIG. 6  illustrates inner member  158  in a fully extended configuration and  FIG. 7  illustrates inner member  158  in a fully retracted configuration and shows seal member  220  folded upon itself. Seal member  220  is configured to prevent fluid ingress through the space between middle tubular member  188  and inner member  158  while allowing inner member  158  to move a sufficient amount so that basket electrode  162  (shown in  FIGS. 2 and 3 ) can be fully deployed during a procedure and fully retracted when not is use. In one embodiment, seal member  220  is fabricated from at least one of polyurethane, silicone, and any other suitable biocompatible material that is flexible and fluid impermeable. 
       FIG. 8  is a cut-away view of distal end  152  of catheter  150  including an alternative seal member  240 . As shown in  FIG. 8 , seal member  240  extends between middle tubular member  188  and inner member  158 . As such, some of the details of catheter  150  shown in  FIG. 3  have been removed for clarity. It should be understood, however, that  FIG. 8  illustrates a specific alternative aspect of catheter  150  shown in  FIG. 3 . 
     Seal member  240  is a rolling seal that extends between middle tubular member  188  and inner member  158 . Seal member  240  includes an inner surface  242  and an outer surface  244 . In addition, seal member  200  includes a first portion  246  and a second portion  248 . Outer surface  244  of seal member  240  contacts an inner surface  250  of middle tubular member  188  and an outer surface  252  of inner member  158 . In one embodiment, outer surface  244  of seal member  240  is not attached to either middle tubular member  188  or inner member  158 , but rather is held stationary with regard to inner surface  250  and outer surface  252  with friction between surfaces  244 ,  250 , and  252 . 
     As shown in  FIG. 8 , seal member  240  is a ring member that surrounds inner member  158  and is at least partially contained within middle tubular member  188 . Seal member  240  is thus able to move with a rolling motion during relative movement between middle tubular member  188  and inner member  158 . Seal member  240  is configured to prevent fluid ingress through the space between middle tubular member  188  and inner member  158  while allowing inner member  158  to move a sufficient amount so that basket electrode  162  can be fully deployed during a procedure and fully retracted when not is use. 
     Seal member  240  includes an inner chamber  254  that contains a fluid. In one embodiment, the fluid is at least one of a gas, such as CO 2 , and a liquid such as silicone gel, water, saline solution, and other biocompatible materials. In one embodiment, seal member  240  is fabricated from at least one of polyurethane, silicone, and any other suitable biocompatible material that is flexible and fluid impermeable. 
       FIG. 9  is a cut-away view of distal end  152  of catheter  150  including a further alternative seal member  260 .  FIG. 9  is directed to seal member  260  that extends between middle tubular member  188  and inner member  158 . As such, some of the details of catheter  150  shown in  FIG. 3  have been removed for clarity. It should be understood, however, that  FIG. 9  illustrates a specific alternative aspect of catheter  150  shown in  FIG. 3 . 
     Seal member  260  extends between middle tubular member  188  and inner member  158 . Seal member  260  includes an inner surface  262  and an outer surface  264 . In addition, seal member  260  includes a first portion  266  and a second portion  268 . Outer surface  264  of seal member first portion  266  contacts and is attached to an inner surface  270  of middle tubular member  188 , and inner surface  262  of seal member second portion  268  contacts and is attached to an outer surface  272  of inner member  158 . In one embodiment, portions  266  and  268  are attached to members  188  and  158 , respectively, with an adhesive. Alternatively, portions  266  and  268  are attached to members  188  and  158 , respectively, with a mechanical fastener. 
     As shown in  FIG. 9 , seal member  260  is a tubular member that surrounds inner member  158  and is at least partially contained within middle tubular member  188 . During extension of inner member  158 , second portion  268  of seal member  260  moves distally with respect to first portion  266 .  FIG. 9  illustrates inner member  158  in a fully retracted configuration and shows seal member  260  folded upon itself. Seal member  260  is configured to prevent fluid ingress through the space between middle tubular member  188  and inner member  158  while allowing inner member  158  to move a sufficient amount so that basket electrode assembly  162  (shown in  FIGS. 2 and 3 ) can be fully deployed during a procedure and fully retracted when not is use. In one embodiment, seal member  260  is fabricated from at least one of polyurethane, silicone, and any other suitable biocompatible material that is flexible and fluid impermeable. 
     Catheter  150  is utilized by inserting distal end  152  into a patient&#39;s vascular system and maneuvering distal end to an appropriate location within a patient&#39;s heart. Once distal end  152  is properly positioned, handle  172  is manipulated so that basket electrode assembly  162  is extended beyond outer tubular member distal end  160 . Basket electrode assembly  162  is moved distally beyond outer tubular member  156  by distal movement of middle tubular member  188  and inner member  158 . Once basket electrode assembly  162  is extended beyond outer tubular member  156 , the movement of inner member  158  is stopped while middle tubular member  188  is further extended distally, thus bending electrode arms  166  radially outwardly. Basket electrode assembly  162  is then maneuvered to properly position electrodes  180  and energy is applied to electrodes  180  so that an electric field is created in the heart. Readings are taken and information is processed so that, for example, a proper reading of the heart is obtained. Basket electrode assembly  162  is retracted into outer tubular member  156  and catheter  150  is then removed from the patient&#39;s vascular system. 
     Exemplary embodiments of catheters, electrode assemblies, and methods of assembly are described in detail above. The catheter, electrode assemblies, and methods are not limited to the specific embodiments described herein, but rather, components of the catheter and electrode assembly and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. It is noted that the exemplary embodiments can be implemented and utilized in connection with many other ablation applications. 
     Although specific features of various embodiments of the invention are shown in some figures and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a figure may be referenced and/or claimed in combination with any feature of any other figure. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. For example, although a three member catheter with a distal seal located between two of the members is described above, it should be understood that any number of tubes can be utilized in the catheter as long as a seal is positioned between, and contacts, two longitudinally extending members.