Abstract:
An ablation therapy system is disclosed comprising an ablation catheter system for treating atrial fibrillation (AF). The ablation catheter system comprises a catheter body including a lumen for receiving a visualization catheter, an ablation element for ablating tissue in a patient&#39;s heart having abnormal electrical activity, a support assembly for supporting the ablation element, the support assembly being supported by the catheter assembly. The support assembly includes a lumen to receive the visualization catheter, wherein the support assembly is configured to rotate and/or pivot with respect to the catheter body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. provisional application Ser. No. 61/715,784, filed Oct. 18, 2012, which is incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an ablation catheter system and method for deploying the same. 
       BACKGROUND OF THE INVENTION 
       [0003]    Atrial fibrillation (“AF”) is a form of cardiac arrhythmia. “Atrial” refers to the top two chambers of the heart known as the atria, where irregularity in AF occurs. The atria are designed to send blood efficiently and rhythmically into the ventricles by way of regular electrical signals. From there, blood is pumped to the rest of the body. In AF, the electrical signals are rapid, irregular and disorganized, and the heart may not pump as efficiently. Individuals with AF have an increased risk of stroke. Stroke occurs if a piece of a blood clot in the atria leaves the heart and becomes lodged in an artery in the brain. 
         [0004]    Current AF treatment options are not perfect. A medical practitioner may use medication as a treatment option. Medication, however, only assists in the management of the symptoms. It is not a cure for AF. Medication can also present side effects that may be more dangerous than AF itself. Another treatment option is electrical cardioversion. In certain circumstances, electrical cardioversion may be used to restore normal heart rhythm with an electric shock, but this option often results in AF reoccurrence. 
         [0005]    When medication is not successful, the medical practitioner may treat AF with ablation catheter therapy. In this procedure, a catheter with an ablation element is introduced through a blood vessel and directed to the atria in the heart muscle. The medical practitioner will localize a specific area of cardiac tissue having aberrant electrically conductive pathways and emitting or conducting erratic electrical impulses. The medical practitioner will then deliver a burst of radio frequency (RF) energy to destroy the tissue that triggers abnormal electrical signals or to block abnormal electrical pathways. In AF, it has been shown that the source of the electrical abnormality is at the opening of each of the four pulmonary veins that come off the left atrium. The medical practitioner therefore targets these openings for ablation catheter therapy. 
         [0006]    While the ablation catheter therapy has become more widely adopted, it is not without its difficulties. In order to effectively treat AF with this procedure, accurate placement and line formation of the lesions (i.e., adjacent lesions without gaps) are critical. Specifically, the success of atrial fibrillation ablation is dependent upon the creation of lesions that adequately disrupt the tissue&#39;s electrical properties. Current techniques do not permit the medical practitioner (operator) to determine exactly where the lesions have been made and whether energy has been efficiently delivered. The medical practitioner relies primarily on changes in electrical signals, which are interpreted as signs of adequate ablation but frequently result in restoration of electrical function after the ablation, and induced edema thus restores. In sum, accurate placement and line formation of ablation lesions are tough to achieve because visualization is inadequate. Consequently, it is thus difficult to effectively treat cardiac arrhythmias such as AF with current ablation technologies and methods. Improved methods and systems are thus needed to determine where ablation lesions have been made and whether the lesions are likely to be long-standing. 
       SUMMARY OF THE INVENTION 
       [0007]    An ablation catheter system and method for deploying the same is disclosed. 
         [0008]    In accordance with an embodiment of the present invention, an ablation therapy system is disclosed including an ablation catheter system for treating atrial fibrillation (AF), the ablation catheter system comprising: a catheter body including a lumen for receiving a visualization catheter; an ablation element for ablating tissue in a patient&#39;s heart having abnormal electrical activity; a support assembly for supporting the ablation element, the support assembly being supported by the catheter assembly, the support assembly including a lumen to receive the visualization catheter, wherein the support assembly is configured to rotate and/or pivot with respect to the catheter body. 
         [0009]    In accordance with yet another embodiment of the present invention, an ablation therapy system is disclosed comprising: (a) an ablation catheter system for treating atrial fibrillation (AF), the ablation catheter system comprising: a catheter body having a lumen for receiving a visualization catheter; an ablation element for ablating tissue in a patient&#39;s heart having abnormal electrical activity; and a support assembly for supporting the ablation element, the support assembly being supported by the catheter assembly, the support assembly including a lumen to receive the visualization catheter, wherein the support assembly is configured to rotate and/or pivot with respect to the catheter body; and (b) a control unit for controlling the support assembly, thereby enabling a user to coordinate rotation and/or pivoting of the support assembly with respect to to the catheter body. 
         [0010]    In accordance with yet another embodiment of the present invention, an ablation catheter system is disclosed for treating atrial fibrillation (AF), the ablation catheter system comprising: a catheter body including a lumen for receiving a visualization catheter; an ablation element for ablating tissue in a patient&#39;s heart having an abnormal electrical activity; and a support assembly for supporting the ablation element, the support assembly being supported by the catheter body, the support assembly including a lumen to receive the visualization catheter, wherein the ablation element is configured to move along the support assembly. 
         [0011]    In accordance with yet another embodiment of the present invention, a method is disclosed of treating atrial fibrillation, the method comprising: providing an ablation therapy system including an ablation catheter system, the catheter system comprising a catheter body having a lumen for receiving a visualization catheter, an ablation element, a support assembly for supporting the ablation element, the support assembly supported by the catheter body for receiving the visualization catheter, the support assembly including a support arm; advancing the ablation catheter system into a heart of a patient; and maneuvering the ablation element to contact tissue of the heart by controlling the support assembly to cause it to pivot and/or rotate with respect to the catheter body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  depicts a perspective view of the ablation catheter system for treating AF in accordance with an embodiment of the present invention. 
           [0013]      FIG. 2  depicts a cross-sectional view of the ablation catheter system in  FIG. 1 . 
           [0014]      FIG. 3  depicts an enlarged cross-section view of the ablation catheter system within circle line  3 - 3  in  FIG. 2 . 
           [0015]      FIG. 4  depicts a cross-sectional view of an ablation catheter system along line  4 - 4  in  FIG. 3 . 
           [0016]      FIG. 5  depicts a cross-sectional view of an ablation catheter system along line  5 - 5  in  FIG. 2 . 
           [0017]      FIG. 6  depicts a side view of the ablation therapy system including the ablation catheter system of  FIG. 1  and the external operational components for operating the ablation catheter system. 
           [0018]      FIG. 7A  depicts the control unit in  FIG. 6  in accordance with an embodiment of the present invention. 
           [0019]      FIG. 7B  depicts the control unit in  FIG. 6  in accordance with another embodiment of the present invention. 
           [0020]      FIG. 8  depicts an enlarged cross-sectional view of the ablation element along line  8 - 8  in  FIG. 2 . 
           [0021]      FIG. 9  depicts an enlarged side view of the distal section of the ablation catheter system of  FIG. 1  in accordance with an alternative embodiment of the present invention. 
           [0022]      FIG. 10  depicts a cross-sectional view of an ablation catheter system along line  5 - 5  in  FIG. 2  in accordance with another embodiment of the present invention. 
           [0023]      FIGS. 11A-11E  depict selected application steps of a method of using the ablation therapy system in  FIG. 6 . 
           [0024]      FIG. 12  depicts an enlarged perspective view of ablation catheter system  20  in  FIG. 11C . 
           [0025]      FIG. 13  depicts high-level steps of the method for treating AF using the ablation therapy system in  FIG. 6  including the ablation catheter system and operational components. 
           [0026]      FIG. 14  depicts the steps of the method for treating AF using the ablation therapy system in  FIG. 6  including the ablation catheter system and operational components. 
           [0027]      FIGS. 15 and 16  depict an implementation for selected steps of the method depicted in  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Ablation therapy system  10  includes ablation catheter system  20 .  FIG. 1  depicts a perspective view of ablation catheter system  20  for treating AF in accordance with an embodiment of the present invention.  FIG. 2  depicts a cross-sectional view of ablation catheter system  20  in  FIG. 1 .  FIG. 3  depicts an enlarged cross-section view of ablation catheter system  20  within circle line  3 - 3  in  FIG. 2 . 
         [0029]    Ablation catheter system  20  includes catheter body  30 , catheter sheath  40 , support assembly  50 , central guidewire  70 , central guidewire sheath  80  and RF ablation element  90  and visualization catheter  100 . Support assembly  50  actually supports ablation element  90  as discussed in more detail below. 
         [0030]    Catheter body  30  has a central inner lumen for receiving visualization catheter  100 . Catheter body  30  is preferably constructed of plastic with and inner lumen diameter of just slightly larger than the diameter of visualization catheter  100  to enable it to pass through. In one embodiment, catheter body  30  has an outer diameter of 4 mm and visualization catheter  100  has an outer diameter of 2.6 mm while the central lumen of the catheter body  30  has a diameter of just slightly larger than 2.6 mm. However, those skilled in the art know than various dimensions of the catheter body  30  and visualization catheter  100  may be designed to achieve desired results. 
         [0031]    Support assembly  50  includes support arms  52 , rear ring  54  and front ring  56 . Rear ring  54  mates with (and supported by) catheter body  30  by way of mating ring  58 . Specifically, rear ring  54  has an annular recess to receive an annular projection of mating ring  58 . Rear ring  54  engages with mating ring  58  in a key configuration as clearly shown in  FIGS. 2 and 3  to enable rear ring  54  to rotate with respect to catheter body  30 . Rear and front rings  54  and  56  each have two opposing blind holes  60 ,  62  and  64 ,  66  respectfully, for receiving support arms  52 . Rear ring  54  includes a lumen that extends through the entire length of ring  54  for receiving visualization catheter  100 . 
         [0032]    Front ring  56  includes a recessed portion with a corresponding diameter as catheter end  190  discussed below of visualization catheter  100  for receiving the front end of visualization catheter  100 . As seen in  FIG. 2 , this recessed portion only extends through a portion of front ring  56 . Front ring  56  includes a lumen of smaller diameter that extends through the entire length of the front ring  56 . This lumen diameter is sized for receiving central guidewire  70 . Rear and front rings  54 ,  56  are preferably each about 5-6 mm in length with an outer diameter of approximately 4 mm. Rear ring  54  has an inner lumen diameter of approximately 2.6 mm for receiving visualization catheter  100 . Front ring  56  has a recess diameter of 2.6 mm. However, those skilled in the art know that various dimensions may be used to achieve desired results. 
         [0033]    In the embodiment shown, support arms  52  comprise two wires  52   a,    52   b  (also referred to as framework wires  52   a,    52   b ) as shown in  FIGS. 1-3  (for example). However, those skilled in the art know that support arms  52  may consist of any number of wires or any other structure to support ablation element  90  as described herein. Wires  52   a,    52   b  each have opposing ends that are press fit (proximally) within blind holes  60 ,  62  and (distally) within blind holes  64 , 66 , respectively for a secure mounting to rear and front rings  54 ,  56 . This is best shown in  FIG. 3  as described above,  FIG. 4  wherein a cross-sectional view of an ablation catheter system is depicted along line  4 - 4  in  FIG. 3  and  FIG. 5  wherein a cross-sectional view of an ablation catheter system depicted along line  5 - 5  in  FIG. 2 . Wires  52   a,    52   b  (of support arms  52 ) are resiliently biased and selectively moveable from a generally linear transport configuration (i.e., internally constrained by the interior walls of sheath  40 ) to a deployed configuration (i.e., unconstrained when sheath  40  is retracted). This is described in more detail below. 
         [0034]    Ablation catheter system  20  further includes a plurality of constraining rings  52   a   1 - 52   a   4  spaced along wire  52   a  for receiving different control lines as described in detail below. Rings  52   a   1 - 54   a   1  are preferably configured around wire  52   a  (concentrically or non-concentrically), but may also be connected to a side of wire  52   a  as known to those skilled in the art. In the embodiment shown, four rings are incorporated. Ring  52   a   1  is spaced along wire  52   a  in the left quadrant of wire  52   a  when it is in expanded form (near front ring  56 ). Rings  52   a   2 - 52   a   4  are spaced along wire  52   a  in the right quadrant of wire  52   a  when it is in its expanded form. In the embodiment shown, rings  52   a   1 - 52   a   4  are positioned to enable ablation element  90  to travel between ring  52   a   1  and ring  52   a   2 . This distance represents approximately 50% of the length of exposed wire  52   a  (majority of movement in the left  90  degree quadrant when wire  52   a  is expanded). However, those skilled in the art know that the number, size and position of the rings are chosen to ensure that (1) the control lines do not interfere with the balloon (described below), (2) the rings do not interfere with ablation element  90  when it travels along a portion of wire  52   a  to achieve proper ablation and (3) the rings do not interfere with ablation catheter system  20  when it is deployed from sheath  40 . Rings  52   a   1 - 52   a   4  are preferably formed as part of wire  52   a  or may be subsequently attached to it. 
         [0035]    Ablation element  90  comprises an electrode as known to those skilled in the art. Ablation element  90  has a design that allows delivery of energy to the tissue through its top surface. Ablation element  90  is also used to measure temperature, optionally measure electrical activity of the tissue location and measure pressure against the tissue as described below. As indicated above, support assembly  50  actually supports ablation element  90 . In this embodiment, ablation element  90  is mounted in a position to slide along wire  52   a  as shown. In detail, ablation element  90  includes a lumen located near the bottom thereof that extends through element  90  for receiving one of wires  52   a,    52   b  (support assembly  50 ) as shown. The lumen shape corresponds in shape to wire  52   a  as best shown in  FIG. 8 . Wires  52   a,    52   b  are preferably square in shape, but they may be any shape so long as they prevent ablation element  90  from rotating around or sliding off wire  52   a  when ablation element  90  is translated. That is, ablation element  90  is adapted to slide or travel along wire  52   a  (of support arms  52 ). When the wire is rotated, however, ablation element  90  also simultaneously moves with wire  52   a  but without rotating. This will ensure that the top face of ablation element  90  is always facing outwardly towards the tissue to be ablated. Ablation element  90  is thus capable of moving with wire  52   a  as well as slide along wire  52   a  as described in more detail below. 
         [0036]    Ablation catheter system  20  further includes spring  42 , tension line  44  and pull line  46 . Tension line  44  and pull line  46  are connected to opposing sides of ablation element  90 . Tension line  44  and pull line  46  each have an end that is secured or tied to ablation element  90  by way of link, hook, ring or other mechanism as known to those skilled in the art, on opposing sides of ablation element  90 . Alternatively, epoxy suitable for surgery may be used to secure tension line  44  and pull line  46  to ablation element  90  as known to those skilled in the art. Spring  42  has two ends, one of which is linked through a hole in wire  52   a  adjacent front ring  56  while the other end is attached to the end of tension line  44 . While tension line  44  is employed, the end of spring  42  may extend a sufficient length and material to act as the tension line itself, which is attached directly to ablation element  90 . Tension line  44  is threaded through constraining ring  52   a   1  along wire  52   a  to constrain or maintain the line position along wire  52   a.  Pull line  46  is threaded through constraining rings  52   a   2 - 52   a   4  so that pull line  46  substantially follows the shape of wire  52   a.  Pull line  46  leaves constraining ring  52   a   4  and extends through a lumen within visualization catheter  100  described below. In short, pull wire  46  is pulled to slide ablation element  90  along wire  52   a  while spring  42  maintains tension on tension line  44  (and hence ablation element  90 ) to enable accurate control of ablation element  90 . When wires  52   a,    52   b  are rotated, pull line  46  is adjusted to permit adequate movement of such wires. 
         [0037]    It is important that the lumen for receiving wire  52   a  is designed to be located near the bottom of ablation element  90  to allow maximum contact between a balloon (or other expandable structure as described below) and wire  52   a  (of support arms  52 ). Such a construction will provide for a better imaging from visualization equipment located within the balloon (as described in detail below). Ablation element  90  also includes a bore to allow the entry of RF irrigation tubing (as also discussed in detail below). Tiny holes are drilled into the sides of this ablation element  90  near the top surface to release cooling saline when energy is being delivered. Ablation element  90  is depicted as showing two exit ports per side, but those skilled in the art know that any number of ports may be used. Once saline enters ablation element  90 , saline exits the tiny exit ports by a channel that has been bored through the middle thereof that connects the exits ports with the saline entry lumen. Ablation element  90  further includes one or more pressure sensors  48  preferably located along the top surface of ablation element  90  as shown in  FIG. 8  for sensing the pressure of ablation element  90  against heart tissue. Sensors  48  are coupled to RF and thermocouple wires as discussed below. 
         [0038]    In the embodiment shown, wires  52   a,    52   b  are preferably made of Nitinol for their deformable but yet memory-retaining properties, but those skilled in the art know that other alloys (or other materials) are possible to achieve the same effect. Wires  52   a,    52   b  are heat treated to a curved height to match the standard size of a pulmonary vein ostium. The lengths of wires  52   a,    52   b  are designed to be slightly longer than the blind holes of rings  54 , 56  when the wires (or other type of support arms  52 ) are under minimal stress (when sheath  40  is retracted). The standard curve size is approximately 27 mm or less and the wire length is approximately 32 mm. However, those skilled in the art know that the length and curve size of wires  52   a,    52   b  may be varied to achieve desired results. While two wires ( 52   a,    52   b ) and one RF ablation element are shown and described herein, those skilled in the art know that any number of wires (or other support arms  52 ) and any number of ablation elements may be used to achieve desired results. These RF ablation elements may be configured as an array or other configuration. As indicated above, ablation element  90  is adapted to slide along arm  52   a  in the embodiment shown in the figures. However, those skilled in the art know that ablation element  90  may be designed to be fixed to wire  52   a  to achieve desired results (in an alternative embodiment). 
         [0039]    Central guidewire  70  extends completely through the ablation catheter system  20 . In the embodiment shown in  FIGS. 1-5 , central guidewire  70  is fixed to front ring  56  within a lumen  68 . Guidewire  70  also extends outside of front ring  56  to assist in the guidance of ablation catheter system  20 . By retracting guidewire  70  (pulling it more proximally) while holding catheter body  30 ), the radius of curvature of wires  52   a,    52   b  (support arms  52 ) increases. This causes such wires to further expand to reach a wall of the pulmonary vein, if necessary. Rotating guidewire  70  rotates front ring  56 , thereby simultaneously rotating wires  52   a,    52   b  (support arms  52 ), ablation element  90  and rear ring  54  to enable the medical practitioner to ablate tissue around the ostium of a pulmonary vein. 
         [0040]    In order to ablate a lesion line around the ostium, ablation catheter system  20  must operate over 360 degrees (in complete rotation or 180 degrees in opposite directions). In the embodiment shown, guidewire  70  may be rotated 180 degrees in both directions to achieve a complete 360 degree ablation line. (Sets of RF and thermocouple wires  130  and irrigation tubing  140  are coupled to ablation element  90  as described below.) In brief, thermocouple wires  130  and irrigation tubing  140  have sufficient slack to enable wires  52   a,    52   b  to move and rotate 180 degrees in either direction. When catheter sheath  40  is retracted back over wires  52   a,    52   b  (support arms  52 ), guidewire  70  and front ring  56  are in its most forward position with respect to the catheter body  30 . Guidewire  70  has a diameter that preferably measures 0.03 inches, but those skilled in the art know that this diameter may be varied to achieve a desired result. Guidewire  70  may be rotated, retracted and fixed in position using a control unit as described in more detail below. 
         [0041]    Ablation catheter system  20  further includes pivot mechanism  120 . Pivot mechanism  120  is configured to cause wires  52   a,    52   b  to pivot with respect to catheter body  30 . Pivot mechanism  120  includes O-ring  122  secured around sheath  80 , midway between the rear ring  54  and catheter end  190  and a flexible line. Pivot mechanism  120  offers the medical practitioner greater control over wires  52   a,    52   b  to position ablation element  90  at desired locations. Pivot mechanism  120  may be retracted and fixed in position using a control unit as described in more detail below. 
         [0042]    As indicated above, ablation element  90  may slide along wire  52   a,  expand outwardly, rotate and ultimately pivot. Because of this range of motion, lateral and vertical movement of ablation element  90  may be coordinated to create a more accurate ablation lesion line (including diagonally) in the heart tissue. 
         [0043]    Ablation catheter system  20  also includes RF and thermocouple wires  130  for delivering energy, measuring temperature at the RF ablation element  90 , measuring the pressure of the ablation element  90  against heart tissue and measuring electrical activity of the localized heart tissue. RF and thermocouple wires  130  are coupled to, i.e., extend within ablation element  90  as shown. RF and thermocouple wires  130  supply RF energy to the ablation element  90  for ablation. A wire line that splits off of wires  130  is coupled directly to pressure sensors  48  to achieve pressure sensing. Another wire line that splits off of wires  130  that is coupled to one or more sensors or other technology (part of RF ablation element  90 , but not shown) for sensing electrical activity and/or temperature of the heart tissue as known to those skilled in the art. In other embodiments, those skilled in the art know that additional sensors for sensing tissue conditions may be mounted on support arms  52 . Ablation catheter system  20  also includes RF saline irrigation tubing  120  for delivering cooling fluid to ablation element  90  via bores within ablation element  90  as described above. 
         [0044]    Ablation catheter system  20  further includes light source  150  and visualization source  160  to provide light and to enable a medical practitioner to visualize the region and target ablation sites. Light source  150  and visualization source  160  run through visualization catheter  100  and extend outwardly from it as described in more detail below. Light source  150  is preferably a fiber optic cable/wires as known by those skilled in the art to transmit light. When wishing to view the tissue wall, light is used to illuminate the distal end of light source  150 . Visualization source  160  is also preferably a fiber optic cable/wires, but the cable/wires incorporates a lens located distally at the end thereof. The distal ends of light source  150  and visualization source  160  are located within balloon  182  (expandable structure  180 ) as described in more detail below. While sources  150  and  160  are described as a fiber optic cable/wires, those skilled in the art know that other materials or mechanisms may be used to transmit light and visualize a target site. For example, visualization source  160  may also be a camera. In addition, in alternative embodiments, more than one light source  150  and/or visualization source  160  may be incorporated with an adequate number of lumens for such sources. For example, a CMOS sensor (complementary metal-oxide semiconductor sensor) that is coupled to a fiber optic cable may be employed as known to those skilled in the art. The CMOS sensor will act as a camera as known to those skilled in the art. In addition, an endoscope may be employed if required. The endoscope will extend through a lumen and sheath within visualization catheter  100  as discussed in more detail below. While visualization source  160  is employed within balloon  182  to visualize a desired region, those skilled in the art know that other visualization components may be used for visualizing a region, and such components may be mounted outside balloon  182  (alternative embodiments). For example, ablation catheter system  20  may include a CMOS sensor mounted to a side of RF ablation element  90  or a support arm  52 . The CMOS sensor acts as a camera as described above. Fiber optic cables will be used to couple the CMOS sensor to an external unit with display as known to those skilled in the art. 
         [0045]    As discussed briefly above, RF and thermocouple wires  130  are coupled to ablation element  90  and connected to an energy delivery unit that also measures and displays energy delivery, time, temperature, ablation sensor pressure and electrical activity of the heart tissue. RF and thermocouple wires  130  run through a lumen within visualization catheter  100 . Wires  130  exit distally out rear ring  54  and run along wire  52   a  until it reaches ablation element  90 . As indicated above, RF and thermocouple wires  130  have sufficient slack between exit point from visualization catheter  100  and ablation element  90 , to provide sufficient clearance necessary to enable ablation element  90  to rotate  180  degrees in each direction. Wires  130  are encompassed in a sheath and sized approximately 0.5 mm in diameter. However, those skilled in the art know that the diameter may be varied in size to achieve desired results. 
         [0046]    RF irrigation tubing  140  runs next to and in the same lumen as RF and thermocouple wires  130  within visualization catheter  100 . It follows the same course, exit and attachment as described for RF and thermocouple wires  130 . The purpose is to deliver cooling saline or other fluid to ablation element  90  when it is delivering energy to the tissue. RF irrigation tubing  140  is flexible and it is fluidly coupled to a tub irrigation unit as described in more detail below. In one embodiment, the outer diameter of RF irrigation tubing  140  is approximately 0.5 mm, but those skilled in the art know that other diameter measurements may be used to achieve the desired results. 
         [0047]    Visualization catheter  100  includes a plurality of lumens that extend from proximal end (near medical practitioner) to a distal end thereof adjacent rear ring  54 .  FIG. 4  illustrates these lumens in detail. In particular, visualization catheter  100  includes lumen  102  for receiving RF and thermocouple wires  130  and RF irrigation tubing  140 . Visualization  100  further includes lumens  104 ,  106  for receiving light source  150  and visualization source  160 , respectfully. In the embodiment shown in  FIGS. 1-4 , lumens  104 ,  106  each include a sheath. These sheaths extend distally from the end of visualization catheter  100  within balloon  182  (discussed below). Light source  150  and visualization source  160  each have a diameter that is appropriately sized to move freely within the sheaths inside lumens  104 ,  106 . The sheaths are employed to prevent fluid from escaping balloon  182  and returning down lumens  104  and  106  (leakage near the medical practitioner). The sheath will be made of an opaque material to enable light to illuminate a region and enable a medical practitioner to visualize a target tissue site using visualization source  160 . In an alternative embodiment, light source  150  and visualization source  160  may be fixed within lumens  104 ,  106  (without a sheath). This also ensures that fluid will not escape and return down lumens  104 ,  106 . In this respect, light source  130  and visualization source  160  extends sufficiently into expandable structure  180  to enable a medical practitioner to visualize virtually all targeted tissue sites. 
         [0048]    Visualization catheter  100  further includes lumen  108  that is large enough to receive central guidewire sheath  80  (and guidewire  70 ) while allowing fluid delivery around central guidewire sheath  80  to inflate an expandable structure  180  such as a balloon as described below. This is clearly shown in  FIG. 4 . Visualization catheter  100  may optionally include a lumen  110  (dotted lines in  FIG. 4 ) that extends the length of visualization catheter  100  to receive an endoscope (not shown). The endoscope may be employed to provide an additional source for accurate viewing. Lumen  110  may also incorporate an endoscope sheath that extends beyond the end of visualization catheter  100  into expandable structure  180  (described in more detail below). The sheath will also be composed of a material that is opaque (at the distal end thereof that extends beyond the distal end of the balloon catheter  90 ) to allow the endoscope to visualize the tissue wall. Lumen  110  is separate from the inside of the visualization catheter  100  so that it can be reused. Visualization catheter  100  further includes lumen  112  for receiving pull line  46 , which extends outwardly from catheter  100  for control by a control unit as discussed below. 
         [0049]    As indicated above, visualization catheter  100  further includes expandable structure  180  that is secured to the end visualization catheter  100 . The expandable structure  180  comprises a balloon  182  (as known to those skilled in the art) as shown in  FIGS. 1-3 . Balloon  182  is attached to the distal end of visualization catheter  100  and fixed within it or alternatively to the surface thereof. With either design, balloon  182  must be fixed to maintain a seal that will prevent any passage of saline or other fluid when balloon  182  is filled. At the distal end, balloon  182  is fixed to catheter end that serves as the distal end of visualization catheter  100 . Because a balloon is used for expansion and visualization, visualization catheter  100  is sometimes referred to as a balloon catheter. 
         [0050]    Balloon  182  is preferably made of an opaque material to allow a medical practitioner to see through it to visualize ablation element  90  and the tissue region intended to be ablated. The material of balloon  182  is flexible to accommodate some variation in pulmonary vein anatomy. The diameter of the visualization catheter  100  is approximately 2.6 mm but those skilled in the art know that any diameter will work that will achieve desired results. Catheter end  190  has a diameter that is sized to receive guidewire sheath  80  and guidewire  70 . Guidewire sheath  80  passes completely through the expandable structure  180  and through catheter end  170 , but it terminates therewith. This enables visualization catheter  100  to translate independently with respect to catheter body  30 . However, guidewire  70  is permitted to run completely through catheter body  30  and out front ring  56 . 
         [0051]    While the expandable structure  180  comprises a balloon  182  in the embodiment shown and described, those skilled in the art know that in alternative embodiments other expandable structures maybe be used to achieve desired results. For example, any clear deformable material such as silicon may be employed to expand and allow visualization. The silicon formed material will incorporate a CMOS sensor and desired fiber optic cables coupled to the sensor for visualization. The silicon may be deployed and maneuvered by axial pressure or by a sheath to contort and position the shape of the silicon as known to those skilled in the art. 
         [0052]    Catheter end  190  fits within the recessed portion of front ring  56  (corresponding diameter as catheter end  190 ) as indicated above. This recessed portion only extends through a portion of front ring  56 . Guidewire  70  is free to move independently with respect to the rest of catheter body  30  to control ablation element  90  by way of wires  52   a,    52   b.  Balloon  182  is filled with saline through lumen  108  of visualization  100 . 
         [0053]    Ablation catheter system  20  via guidewire  70  and sheath  40  is steerable to enable catheter body  30  to be advanced into all four pulmonary veins. When sheath  40  is retracted, catheter body  30  is advanced over wires  52   a,    52   b  will expand to their heat-treated position. 
         [0054]      FIG. 6  depicts a side view of ablation therapy system  10  including the ablation catheter system  20  of  FIG. 1  and the external operational components for operating the ablation catheter system  20 . Specifically, ablation therapy system  10  further includes a control unit  200 , inflation unit  230 , light generator and visualization unit  240 , tube irrigation unit  250 , RF transceiver  260 , display  270  coupled to RF transceiver  260 , intracardiac electrogram  280  and display  290  coupled to intracardiac electrogram  280 . 
         [0055]    These components are shown as lines that are connected to catheter body  30 . The lines represent tubes and cables known to those skilled in the art as discussed in more detail below. In one embodiment, many of the tubes and cables that extend from catheter body  30  may enter a coupling mechanism or handle (not shown) as known to those skilled in the art. The handle acts as a junction for such tubes and cables to enable a medical practitioner to quickly and easily connect the ablation catheter system  20  components. Alternatively, some or all of the tubes and cables may be coupled, without such a handle, separately to such operational components described above. 
         [0056]    Control unit  200  is coupled to guidewire  70 . The medical practitioner uses the control unit  200  to control the movement of guidewire  70 . Guidewire  70  can be rotated, advanced and/or retracted to thereby control support arms  52 . Control unit  200  may also be used to control visualization catheter  100  or it may be manipulated manually as known to those skilled in the art. 
         [0057]      FIG. 7A  depicts control  200  unit in  FIG. 6  in accordance with an embodiment of the present invention. In  FIG. 7A , control unit  200  includes handle  202  and it comprises a lever  204  positioned midway between the ends of handle  202  and wheel  206  located on an end of the handle  202 . Handle  202  has a lumen to receive guidewire  70 . Guidewire  70  is shown in dotted lines in  FIG. 7A . In order to set up control unit  200  with guidewire  70  for operation, the medical practitioner slides handle  202  over guidewire  70  and rotates (i.e., tightens) lever  204  to clamp against guidewire  70  as known to those skilled in the art. In an alternative construction, wheel  206  may be a separate component and threaded or snap fitted onto the handle  202 . Handle  202  also includes a lumen to receive flexible line  124  of pivot mechanism  120 . Flexible line  124  is also shown in dotted line in  FIG. 7A . Flexible line  124  is tied to a small grasping ball/knob as shown. Handle  202  may include a gear or pulley mechanism to assist in the operation of flexible line  124  as known those skilled in the art (e.g., secure and release line  124 ). Handle  202  also includes a lumen for receiving pull line  46 . Pull line  46  is also shown extending through tied to ball or knob. Handle  202  may also include a gear or pulley mechanism to assist with the operation of the pull line  46  as known to those skilled in the art to move ablation element  90  along arm  52   a.  Handle  202  may also be adapted to control visualization catheter  100  or it may be controlled manually as known to those skilled in the art. 
         [0058]    In operation, when wheel  206  rotates, handle  202  and hence guidewire  70  rotates. While holding catheter body  30 , the medical practitioner may push or pull wheel  206  to expand or contract wires  52   a,    52   b  (support arms  52 ). The medical practitioner may control flexible line  124  and/or pull line  46  through control unit  200  to cause support arms  52  to pivot and/or to make ablation element  90  slide along wire  52   a,  respectfully. Support arms  52  will return to an un-pivoted position when the practitioner releases flexible line  124 . Ablation element  90  will return to a resting position adjacent to front ring  56  when the practitioner releases pull line  46 . Control unit  200  shown in  FIG. 7A  is one embodiment for controlling guidewire  70 . 
         [0059]      FIG. 7B  depicts control unit  200  in  FIG. 6  in accordance with another embodiment of the present invention. In detail,  FIG. 7B  depicts a control unit that is computerized and motorized to control the operation of the components of ablation catheter system  20 . In  FIG. 7B , control unit  200  includes a plurality of gear mechanism  208 - 212  for operating, i.e., driving the components of ablation catheter system  20 , thereby moving ablation element  90  and visualization catheter  100  as known to those skilled in the art. Specifically, gear mechanism  208  is for wire  52   a  rotation and gear mechanism  210  is for wires  52   a,    52   b  expansion (by way of central guidewire  70 ). Gear mechanism  212  is for controlling the movement of ablation element  90  along wire  52   a  (via pull line  46 ). Gear mechanism  214  is for moving visualization catheter  100 . These gear mechanisms may be implemented using a ratchet system (similar to a wrench) and/or screw or other mechanism as known to those skilled in the art. For example, coordinated rotation and translation together, may be achieved by a screw turn or click to enable ablation element  90  to essentially move diagonally (to effect diagonal lesion formation). Gear mechanism  212  may also include an inflation unit (instead of inflation unit  230  as described above). 
         [0060]    Control unit  200  includes motors  216 ,  218 ,  220 ,  222  for controlling the operation of gear mechanisms  208 ,  210 ,  212 ,  214 , respectively. Control unit  200  further includes processor  223  for executing computer programs to control the operation of motors  216 - 222  (and hence ablation element  90 ) and memory  224  connected to processor  223  for storing computer program to be executed by processor  223  as known to those skilled in the art. Control unit  200  further includes hard drive  225  as a storage device for storing measured values etc. and video card  226  for connecting to display  228 . Control unit  200  will also include user interface  227  that may be manipulated by the medical practitioner to control the operation of control unit  200 . User interface  227  may be a joystick or other mechanism to effect instructions to the processor. While the components of control unit  200  are described herein, those skilled in the art know that other components may be included or excluded to achieve desired results. 
         [0061]    While two exemplary embodiments of control unit  200  have been described herein, those skilled in the art know that other control units or other mechanisms may be used to achieve desired results. 
         [0062]    Returning to  FIG. 6 , inflation unit  230  is connected to lumen  108  to provide fluid to visualization catheter  100 . Inflation unit  230  delivers fluid to lumen  108  through interface tubing (not shown) as known to those skilled in the art. Saline is preferably used to inflate the balloon  182 . Saline enables the medical practitioner to see through the balloon  182 . However, those skilled in the art know that fluids other than saline may be used to achieve desired results. 
         [0063]    Light generator and visualization unit  240  is coupled to light source  150  and visualization source  160  via an optical coupler interface  242  (shown in dotted line) to provide light to such light source  150  and camera and/or other technologies as known to those skilled in the art for visualizing a region using visualization source  160 . In addition, Light generator and visualization unit  240  will incorporate technology to take images and/or video as known by those skilled in the art. 
         [0064]    Ablation therapy system  10  may also include other components and/or technologies necessary for using an endoscope as known to those skilled in the art (and ablation catheter system  20  is designed with a lumen to receive an endoscope). 
         [0065]    Tube irrigation unit  250  is coupled to RF irrigation tubing  140  for providing saline or other fluids to cool ablation element  90  during ablation. Tube irrigation unit  250  may be a handheld pump, motorized pump or other mechanism that pumps fluid through irrigation tubing  120  as known to those skilled in the art. 
         [0066]    RF transceiver  260  as known to those skilled in the art is coupled to RF and thermocouple wires  130  for delivering an RF energy signal to ablation element  90  and to measuring temperature off of ablation element  90 . RF transceiver  260  may include an internal display for displaying RF settings, energy readings, sensor readings and other information or such information may be displayed on external display  270 . Display  270  is used to display signals representing electrical activity of the target tissue. 
         [0067]    Intracardiac electrogram  280  as known to those skilled in the art is coupled to RF and thermocouple wires  130  for measuring electrical activity of target tissue as known by those skilled in the art. Display  290  is coupled to intracardiac electrogram  260  and it is used in to display measured readings. 
         [0068]    While the components identified above are described for ablation therapy system  10 , those skilled in the art know that additional components or less components may be employed in accordance with other embodiments of the present invention. For example, display  290  may not be needed, if intracardiac electrogram  280  has a display. In alternative embodiments, ablation catheter system  20  may incorporate different components for achieving desired results. For example, ablation catheter system  20  may incorporate one or more wheels (or other rotation elements) coupled to RF ablation element  90  with motorized capability (components) as known to those skilled in the art to enable RF ablation element  90  to move along heart tissue. That is, the wheels will rotate and travel along the tissue, thereby pulling RF ablation element  90  along the tissue. The motorized components (e.g., spin motor) will be under the control of control unit  200 . 
         [0069]    Motion/operation. The following describes the motion/operation of ablation catheter system  20  shown in the figures. 
         [0070]    Rotation of RF ablation element  90  independent of balloon  182 . Central guidewire  70  is rotated at the proximal end of the catheter body  30  by control unit  200  180 degrees in each direction from its initial point for a full 360 degrees. If a medical practitioner rotates central guidewire  70 , front ring  56  rotates which results subsequently rotates front ring  54 , support arms  52  (wires  52   a,    52   b ) and ablation element  90 . 
         [0071]    Expanding support arms  52 . The medical practitioner advances catheter body  30  through catheter sheath  40 , until support arms  52  move past the distal end of catheter body  30 . This will cause support arms  52  to assume their curved position (e.g., heat treated position). If further expansion is necessary, catheter body  30  is held in a fixed position and central guidewire  70  is retracted using control unit  200 . This force pulls front ring  56  towards balloon  182 , and as catheter body  30  and rear ring  54  are fixed, it will increase the curvature of support arms  52  shifting RF ablation element  90  to a higher position. 
         [0072]    Expanding balloon  182 . Inflation unit  230  delivers saline through lumen  108  of visualization catheter  100  to fill balloon  182  with saline resulting in its expansion. 
         [0073]    Rotation of RF ablation element  90  in conjunction with balloon  182 . Central guidewire  70  is fixed to catheter body  30  externally via control unit  200  and rotated together proximally, resulting in rotation of both RF ablation element  90  (as previously described) and balloon  182  distally. 
         [0074]    Advancing and/or rotating balloon  182  independent of catheter body  30 , ablation element  90  and front ring  56 . While catheter body  30  and central guidewire  70  are fixed, the medical practitioner may advance or rotate visualization catheter  100  thus allowing balloon  182  to move independently of catheter body  30 , RF ablation element  90  and front ring  56 . 
         [0075]      FIG. 8  depicts an enlarged cross-sectional view of the ablation element along line  8 - 8  in  FIG. 2 . This is described above. 
         [0076]      FIG. 9  depicts an enlarged side view of the distal section of the ablation catheter system  20  of  FIG. 1  in accordance with an alternative embodiment of the present invention. In this embodiment, catheter ablation system  20  includes guidewire  70  as describe above. However, guidewire  70  is a separate component that is not initially fixed to catheter body  30 . Guidewire  70  is first advanced into the heart as known by those skilled in the art. Then, catheter body  30  incorporating visualization catheter  100  is advanced over guidewire  70 . In this respect, the guidewire  70  acts a true guide. However, guidewire  70  includes spring  75  that expands into a complementary sized recess within the lumen of front ring  56  when catheter body  30  is advanced into place. The ablation catheter system  20  then functions similarly as described above. 
         [0077]      FIG. 10  depicts a cross-sectional view of an ablation catheter system along line  5 - 5  in  FIG. 2  in accordance with another embodiment of the present invention. In this embodiment, lumen  108  of visualization catheter  100  encompasses, i.e., surrounds several lumens and components that appeared in other parts of visualization catheter  100  in the embodiment described above. In particular, lumen  108  encompasses light source  150  and visualization source  160  respectfully as describe above and guidewire sheath  80  and guidewire  70 . The remaining structure is similar to that shown in  FIG. 4 . 
         [0078]    Reference is now made to  FIGS. 11A-11E .  FIGS. 11A-11E  depict selected application steps of a method of using the ablation therapy system  10  in  FIG. 6 . In the beginning stages of the ablation procedure, ablation catheter system  20  is inserted in a blood vessel (not shown) that leads to left atrium  330  of heart  310  as known to those skilled in the art. The distal end of guidewire  70  (permanent part of ablation catheter system  20  in this embodiment) and composition of catheter sheath  40  act as a guide to enable ablation catheter  20  to advance through the blood vessel and heart. Ablation catheter system  20  is passed through an opening created in the septum  320  that separates the right and left atria into left atrium  330 . In  FIG. 11A , ablation catheter system  20  is advanced to a position within atrium  330  adjacent a pulmonary vein  340 . Ablation catheter system  20  is shown in an un-deployed configuration wherein sheath  40  covers wires  52   a,    52   b  (support arms  52 ) and they have not been retracted to expose wires  52   a,    52   b  (support arms  52 ). In  FIG. 11B , sheath  40  is shown in a retracted position wherein wires  52   a,    52   b  (support arms  52 ) of ablation catheter system  20  are expanded to their biased shape (e.g. pre-heat treated shape as shown). 
         [0079]      FIG. 11C  depicts ablation catheter system  20  in an advanced position wherein wires  52   a,    52   b  (support arms  52 ) encircle the opening or entry of the pulmonary vein  340  known as the ostium, and a first tissue site is ablated by RF energy (heating) of the contacted tissue. As depicted in  FIG. 11C , ablation element  90  is positioned against the target tissue along with the assistance of balloon  182  (of expandable structure  180 ). That is, balloon  182  is positioned and expanded against wires  52   a,    52   b  (support arms  52 ) to ensure that ablation element  90  is firmly against the tissue. This is shown detail in  FIG. 12 .  FIG. 12  depicts an enlarged perspective view of ablation catheter system  20  in  FIG. 11C . In  FIG. 11 , balloon catheter  100  is maneuvered to position the balloon  182  against wires  52   a,    52   b.  In this respect, balloon  182  is used to maintain ablation element  90  in place against the target tissue as well to sufficiently block blood to enable a medical practitioner to visualize the tissue surface. 
         [0080]      FIG. 11D  depicts ablation catheter system  20  in an advanced position wherein wires  52   a,    52   b  encircle the opening or entry of the pulmonary vein  340  known as the ostium, and second tissue site is ablated by RF energy delivered to ablation element  90 . As depicted in  FIG. 11D , ablation element  90  is positioned against a second target tissue site along with the assistance of balloon  182 . Wires  52   a,    52   b  (of support arms  52 ) are shown pivoted and expanded to ensure that ablation element  90  is positioned against the second tissue site. Ablation catheter system  20  is maneuvered and tissue is ablated at other tissue sites. The intended result is a substantially uniform continuous ablation line with adjacent lesions circumferentially around the pulmonary vein as visualized by an endoscope camera for example. 
         [0081]      FIG. 11E  depicts ablation catheter system  20  in a retracted position wherein wires  52   a,    52   b  are expanded in their natural (e.g., heated treated) position (as if they were first exposed when sheath  40  is removed). 
         [0082]    In the embodiments shown and described herein, balloon  82  aids in the position of support arms  52  and RF ablation element  90 . However, in alternative embodiments, support arms  52  may be used to deploy, shape, reposition and re-deform balloon  182  as known to those skilled in the art. 
         [0083]      FIG. 13  depicts high-level steps of the method for treating AF using the ablation therapy system  10  in  FIG. 6  including the ablation catheter system  20  and operational components. In such form, the method begins at step  400  wherein ablation catheter system  20  is advanced into the region of the pulmonary vein  340 . At step  410 , the support assembly  50  is controlled by control unit  200  to maneuver and position ablation element  90  in contact with the tissue at a desired site. Expandable structure  180  (balloon  182 ) is controlled to enable visualization of the target tissue and/or stabilize the ablation element  90  against target tissue at step  420 . Light source  150  and visualization source  160  are employed. The method proceeds to step  430  wherein the tissue is ablated. The method moves to step  430  wherein steps  410 - 430  are repeated. In this respect, the method produces a continuous ablation line of lesions without gaps. These are the high-level steps of the method for treating AF, but those skilled in the art know that some or other steps (possibly in different order) may be employed in accordance with the present invention. For example, the electrical activity or trigger of the target tissue may be measured, if needed, using ablation element  90 , RF and thermocouple wires  130  and intracardiac electrogram  260  as described above. 
         [0084]      FIG. 14  depicts the steps of the method for treating AF using the ablation therapy system in  FIG. 6  including the ablation catheter system and operational components. In particular, the method beings (again) with step  500  and  510  wherein ablation catheter system  20  is advanced into the left atrium of the heart and into the region of the ostium of the pulmonary vein. At step  520 , the catheter body  30  is advanced beyond catheter sheath  40  to expose wires  52   a,    52   b  and balloon  182 . The sheath is held while the catheter body  30  is advanced. Alternatively, sheath  40  may be pulled while catheter body  30  is held in place. Next, ablation element  90  is maneuvered and positioned against the tissue at the desired site at step  530 . This is accomplished when a medical practitioner uses control unit  200  to manipulate wires  52   a,    52   b.  At step  540 , the balloon  182  is positioned (including expansion) to enable visualization. Balloon  182  may also be used to stabilize ablation element  90  against atrial tissue. While steps  530  and  540  are shown and described in that order, those skilled in the art know that in practice, these steps may be repeatedly performed in that order or in reverse to ensure proper positioning of both the ablation element  90  and balloon  82 . Hence,  FIG. 14  is shown with a dotted arrow line from step  540  to  530 . However, the medical practitioner must take care to ensure that the pull line  46  extending from visualization catheter  100  does not incidentally pull ablation element  90  out of place when catheter  100  is moved. 
         [0085]    Next, light source  150  and visualization source  160  are activated for illuminating and visualizing a region at step  550 . The medical practitioner will activate RF transceiver and ablate the tissue with ablation element  90  at step  560 . The method moves to step  570 , wherein balloon  182  is deflated. At step  580 , steps  530 - 570  are repeated in attempt to create a substantially uniform continuous ablation line with adjacent lesions (without gaps) circumferentially around the pulmonary vein. The medical practitioner may optionally measure electrical activity of targeted tissue sites before or after ablation is performed as described above. 
         [0086]    Once completed, Catheter body  30  is retracted within catheter sheath  40  to cover wires  52   a,    52   b  and balloon  182  and ablation catheter system  20  is withdrawn at steps  590  and  600 , respectfully.  FIG. 13  illustrates the detailed steps of the method for treating AF using ablation therapy system  10 , but those skilled in the art know that less, more or different steps maybe be performed (or possibly in different order) in accordance with the present invention. 
         [0087]      FIGS. 15 and 16  depict an implementation for selected steps of the method depicted in  FIG. 14 . In particular, step  530  in  FIG. 14  is implemented by step  530 - 1  in  FIG. 15 . Specifically, the medical practitioner controls wires  52   a,    52   b  by using control unit  200  to place ablation element  90  in contact with the tissue. This is done by rotating guidewire  70  to rotate wires  52   a,    52   b,  to thereby align ablation element  90  with a tissue site at sub-step  530 - 1 A. Pull line  46  is likely adjusted to permit rotation of wires  52   a,    52   b.  At sub-step  530 - 1  B, pull line  46  is then used to translate ablation element  90  along wire  52   a.  At sub-step  530 - 1  C, guidewire  70  is pulled to further expand wires  52   a ,  52   b  or guidewire  70  is pushed forward to contract wires  52   a,    52   b  as needed to accurately contact the tissue. Optionally, flexible (pivot) line  124  is pulled to pivot wires  52   a,    52   b  to ensure an accurate contact between ablation element  90  and the tissue at sub-step  530 - 1  D. Because of the wide range of control, ablation element  90  is able to move diagonally to coordinate proper lesion line formation. 
         [0088]    Referring to  FIG. 16 , step  540  in  FIG. 13  is implemented by step  540 - 1  in  FIG. 15 . The medical practitioner controls balloon  182  to enable the physician to visualize the tissue site and/or stabilize the ablation element against the tissue. This is done by sub-steps  540 - 1 A and  540 - 1  B. In step  540 - 1 A, the medical practitioner advances or retracts visualization catheter  100  to move balloon  182  longitudinally forward and back. At sub-step  540 A- 2 , balloon  182  is inflated to enable visualization (e.g., block blood) and/or to stabilize wires  52   a,    52   b  against the tissue. (As indicated above, the sub-steps shown in  FIG. 15  may be alternated with sub- steps in  FIG. 16  in practice during the procedure.)  FIGS. 15 and 16  illustrate the detail implementation of selected steps of the method for treating AF but those skilled in the art know that less, more or different steps maybe be performed (or possibly in different order) in accordance with the present invention. 
         [0089]    It is to be understood that the disclosure teaches examples of the illustrative embodiments and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the claims below.