Abstract:
Multifunction and radial deflection wires ( 66, 64 ) extend from a catheter shaft ( 8 ) and into a handle ( 4 ). The multifunction wire is pulled and pushed longitudinally and is rotated about its axis to change the stiffness of and to laterally deflect the tip portion ( 12 ). A curve size manipulator ( 32 ) on the handle body ( 24 ) moves the multifunction wire longitudinally but does not hinder its rotational movement. Rotation of a lateral deflection manipulator ( 38 ) on the handle causes the proximal end ( 70 ) of the multifunction wire to rotate about its own axis; the free longitudinal movement of the proximal end is unhindered. Any initial corkscrewing or other deflection of the tip portion can be removed at assembly by rotating the proximal end ( 68 ) of the radial deflection wire. The longitudinal movement of the manipulators can be limited by movable stops ( 120 ). The longitudinal positions of the abutment faces ( 126, 128 ) of the stops preferably change according to their longitudinal (distal or proximal) orientation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a divisional application of prior application Ser. No. 09/382,352 filed Aug. 25, 1999 which is a divisional of prior application Ser. No. 08/920,340, filed Aug. 27,1997 now U.S. Pat. No. 5,987,344 which is a continuation-in-part of prior application Ser. No. 08/694,363, filed Aug. 8,1996 now U.S. Pat. No. 5,826,576. 
     This application is related to U.S. Pat. No. 5,545,200, issued Aug. 13, 1996 entitled “Steerable Electro-physiology Catheter.” This application is a continuation-in-part of U.S. patent application Ser. No. 08/694,363, filed Aug. 8, 1996, entitled “Electrophysiology Catheter with Multi-Function Wire and Method for Making. ” The disclosure of each is incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Electrophysiology catheters are designed for use in mapping and/or ablation of the heart. Electrophysiology catheters typically include a number of band electrodes mounted to the tip portion of the catheter shaft and a tip electrode at the distal end of the catheter shaft. To properly manipulate the electrodes against the target sites within a heart, the tip portion must be flexible and capable of being manipulated into a variety of shapes. U.S. patent application Ser. No. 5,487,757, entitled “Multicurved Deflectable Catheter, ” the disclosure of which is incorporated by reference, discloses an electrophysiology catheter in which the tip portion can be deflected radially by pulling on a manipulator wire and also defected laterally by rotating a core wire which extends into the tip section. In addition to the manipulator and core wires, this patent discloses the use of an axially slidable stiffener wire, the distal end of which can be located at different positions along the tip portion to change the stiffness of the tip, and thus the general size of the curve in the tip. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to improvements for a catheter assembly of the type having a multifunction wire. The proximal end of the multifunction wire is both rotated about its longitudinal axis and slid longitudinally. This rotational and longitudinal movement occurs when the user operates lateral deflection and longitudinal position manipulators mounted to the handle body. 
     The catheter assembly also includes a catheter shaft extending from the distal end of a handle body with the proximal portion of a multifunction wire extending into the handle body. The multifunction wire is pulled and pushed longitudinally and is rotated about its axis to provide multiple functions for the catheter shaft. 
     The longitudinal position manipulator is preferably slidably mounted to the body of the handle for movement between first and second longitudinally spaced apart positions. The longitudinal position manipulator is connected to the multifunction wire through a rotary coupling so that movement of the longitudinal position manipulator causes longitudinal movement of the multifunction wire but does not hinder the free rotational movement of the proximal portion of the multifunction wire. 
     The lateral deflection manipulator is preferably rotatably mounted to the body of the handle. The proximal end of the multifunction wire preferably has an elongate drive adapter which passes through a hole in a first gear; the first gear is rotatably mounted to the handle body at a fixed position aligned with the lateral defection manipulator. The lateral deflection manipulator is rotatably coupled to the first gear, and thus to the drive adapter, typically by second and third gears. The drive adapter and first gear have interfering torquing surfaces so that rotation of the lateral deflection manipulator causes the drive adapter, and thus the proximal portion of the multifunction wire, to rotate about its own longitudinal axis while not hindering the free longitudinal movement of the drive adapter through the first gear. 
     In addition to the multifunction wire, a radial deflection wire, for example, can also be used with the invention. The proximal end of the radial deflection wire is preferably coupled to a radial deflection manipulator in a way which permits the rotary orientation of the proximal end of the radial deflection wire to be adjusted relative to the handle. This is typically done to remove, during assembly, undesirable twisting, corkscrewing, or other deflection of the tip portion of the catheter shaft. The longitudinal movement of the longitudinal position manipulator and the radial deflection manipulator can be limited by use of movable stops which can be mounted to the handle body at a range of longitudinal positions. The longitudinal stops can be configured so that the longitudinal positions of the abutment faces of the stops change according to the orientation of the stops. 
     The multifunction wire preferably extends into the flexible tip portion of the catheter shaft and is freely longitudinally slidable within the tip portion. Torquing force, which creates lateral deflection of the radially deflected tip portion, is preferably transmitted from the multifunction wire to the tip portion by providing both the distal end of the multifunction wire and the multifunction wire lumen within the tip portion with interfering torquing surfaces, such as created when the two have generally complementary oblong cross-sectional shapes. 
     Other features and advantages of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a simplified overall view of a catheter assembly made according to the invention; 
     FIG. 2 is an exploded isometric view of the handle of the catheter assembly of FIG. 1; 
     FIG. 3 is an enlarged external isometric view of the central portion of the upper body part of FIG. 2 from a reverse direction showing a spring finger and an over-rotation stop; 
     FIG. 4 is an enlarged exploded isometric view of a slider and the proximal end of the radial deflection wire before being secured to the adjustment adapter of FIG. 2; 
     FIG. 5 is a cross-sectional view of the catheter shaft of FIG. 1 taken along line  5 — 5  of FIG. 1; 
     FIG. 6 is a cross-sectional view of the tip portion of the catheter shaft of FIG. 1 taken along line  6 — 6  of FIG. 1; 
     FIG. 7 is an enlarged cross-sectional view taken along line  7 — 7  of FIG. 1; 
     FIG. 8 is an enlarged side view of a stop of FIG. 2; 
     FIG. 9 is an enlarged cross-sectional view taken along line  9 — 9  of FIG. 1; 
     FIG. 10 illustrates the tip portion of the catheter of FIG. 1 after radial deflection, as shown by the solid line arrow and the solid line radially-deflected tip portion, and after in-plane lateral deflection, as illustrated by the dashed line arrow and the dashed line radially- and laterally-deflected tip portion. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a catheter assembly  2  including a proximal end assembly or handle  4  from which a catheter  6  extends. Catheter  6  includes a catheter shaft  8  having a main, proximal portion  10  and a distal, tip portion  12  joined at a butt joint  14 . Tip portion  12  is preferably more flexible than main portion  10  and has a number of electrodes  16  along its length, and typically a tip electrode  18  at the distal end  20  of catheter shaft  8 . Catheter shaft  8  has a proximal end  22  mounted to and extending from handle  4 . 
     FIG. 2 illustrates handle  4  in more detail. Handle  4  includes a hollow body  24  comprising an upper body part  26  and lower body part  28 . Handle  4  includes a radial deflection manipulator  30  and a curve size manipulator  32  both slidably mounted to handle  4  for movement along the longitudinal length of the handle, that is parallel to arrows  34 ,  36  of FIG.  1 . Handle  4  also includes a rotatable lateral deflection manipulator  38  in the form of a split ring. Manipulator  38  includes a first split ring portion  40  and a second split ring portion  42 . First and second portions  40 ,  42  define an internal gear  43  for purposes to be discussed below. Second split ring portion  42  has a stop  44  centered along its distal end which engages an over-rotation stop  46  formed on upper body part  26 , see FIG.  3 . Rotation of manipulator  38  is limited to just under 360°, that is about 180° each way from the position of FIG. 2 (when assembled), by the engagement of stops  44 ,  46  at either end of the travel. 
     Upper body part  26  has a pair of annular barriers  48 ,  50  which keep lateral deflection manipulator  38  properly aligned on hollow body  24 . Annular barrier  50  has a neutral alignment projection  52  which aligns with a similar projection  54  on first split ring portion  40  when lateral deflection manipulator  38  is at its centered or neutral position. The user is provided additional tactile and audible indication of this centered or neutral alignment of manipulator  38  relative to body  24  by the engagement of a projection  56  formed on a spring finger  58 , the spring finger being a portion of upper body part  26  between annular barriers  48 ,  50 . Projection  56  engages a recess, not shown, formed on the inner surface of first split ring portion  40  at a location generally aligned with projection  54 . 
     Proximal end  22  of catheter shaft  8  extends into a strain relief  60  at the distal end  62  of body  24 . Catheter  3  includes a radial deflection wire  64  and multifunction wire  66  passing through catheter shaft  8 . The proximal ends  68 ,  70  of wires  64 ,  66  extend into hollow body  24 . FIG. 4 illustrates proximal end  68  of radial deflection wire  64  having a section of hypotube  72  secured to distal end  68 . The distal end  74  of hypotube  72  is flattened for keyed access into an oblong opening  76  formed in an adjustment adapter  78 . Adjustment adapter  78  has an enlarged, serrated end  80  and a smaller diameter cylindrical end  82  sized to fit within a T-slot  84  formed in a slider  86 . T-slot  84  is sized so that adjustment adapter  78  fits snugly within the T-slot through frictional engagement of the adjustment adapter in the T-slot. However, the exposed serrated end  80  of adjustment adapter  76  permits the rotary orientation of proximal end  68  of radial deflection wire  64  to be adjusted through the use of a small screwdriver or other tool which can be used to rotate adjustment adapter  78  within T-slot  84  overcoming the frictional resistance which normally prevents such rotation. This is useful because it permits, at assembly, any corkscrewing or other undesirable deflection of tip portion  12  to be removed or at least substantially reduced. 
     As shown in FIGS. 5 and 6, radial deflection wire  64 , which is preferably coated with a lubricious material such as PTFE, passes through a main lumen  88  formed in main portion  10  of catheter shaft  8  and then through a radial deflection lumen  90  formed in tip portion  12 . Radial deflection wire  64  is preferably secured to tip portion  12  at or near distal end  20  of catheter shaft  8 . As can be seen from these figures, multifunction wire  66 , thermocouple wires  92  and electrode wires  94  will also pass through main lumen  88 . Electrode wires  94  and thermocouple wires  92  pass through an electrode wire lumen  95  within tip portion  12  while the distal end  96  of multifunction wire  66  passes through a lateral deflection lumen  98 . Lateral deflection lumen  93  is sized with an enlarged central region to permit the proximal portion of multifunction wire  66  to pass through lumen  98 . Otherwise, lumen  98  has a flattened shape similar to the flattened shape of distal portion  96  so that the torque transmitting, interfering torquing surfaces  100 ,  102  of distal portion  96  and lateral deflection lumen  98  oppose. This arrangement permits distal end  96  of multifunction wire  98  to slide freely longitudinally within lateral deflection Lumen  98  but permits lateral deflection of tip portion  12  by the rotation or torquing of multifunction wire  96 . 
     The size of the curve of tic portion  12  can be adjusted by adjusting how far distal portion  96  extends into tip portion  12 . The farther distal portion  96  extends into tip portion  12 , the stiffer the tip portion becomes and the smaller the radius of curvature when radial deflection wire  64  is actuated. Typically radial deflection wire  64  is actuated by being pulled; in appropriate circumstances radial deflection wire  64  can be sufficiently stiff so that radial deflection can be achieved by either pulling or pushing on the radial deflection wire  64 . As is conventional, thermocouple wires  92  extend to tip electrode  18  to monitor the temperature at the tip electrode while electrode wires  94  extend to the various electrodes  16 ,  18 . 
     FIG. 7 illustrates slider  76  supported by lower body part  28 . Slider  78  has a central recess  104 , see FIG. 4, with an enlarged upper region sized to snap over and slide along a pair of guide rails  106 . A spring-loaded pin  108 , see FIG. 2, extends upwardly from a pin housing  110  of slider  76 , passes through a longitudinally extending slot  112  formed in upper body part  26  and engages a blind bore, not shown, formed within an interior surface of radial deflection manipulator  30 . In this way, longitudinal movement of radial deflection manipulator  30  causes like longitudinal movement of slider  76  and thus of the proximal end  68  of radial deflection wire  64 . 
     Radial deflection manipulator  30  can be secured at any desired position along slot  112 . To do so, manipulator  30  includes a serrated ring  114  rotatably mounted about a collet assembly  116 . Collet assembly  116  includes a pair of split rings  118 . One or both of serrated ring  114  and split rings  118  have cam surfaces so that rotation of serrated ring  114  about hollow body  24  causes split rings  118  to be biased against the outer surface of hollow body  24  thus securing manipulator  30  at the desired longitudinal location. 
     Longitudinal movement of slider  76  is limited by engagement of pin  108  at either end of slot  112 . If desired, this amount of longitudinal movement can be limited in both distal and proximal directions through the use of stops  120 . Stops  120 , see FIGS. 2 and 8, each have an abutment portion  122  and a pair of legs  124 . Each abutment portion  122  has first and second longitudinally-faces  126 ,  128 . Legs  124  are longitudinally offset from the longitudinal center of abutment portion  122 . Lower body part  28  has a series of spaced apart positions  130  along its length sized to accept legs  124 . Each position  130  is spaced apart by, or example, 2.29 mm (0.090 inch). However, the offset nature of legs  124  changes where faces  126 ,  128  are positioned even though legs  124  may be located at a particular position  130 . In the preferred embodiment the longitudinal position or faces  126 ,  128  vary by 1.14 mm (0.045 inch) depending upon which face  126 ,  128  faces in the distal direction. In this way the limit of travel of slider  76  can be adjusted in 1.14 mm increments as opposed to 2.28 mm increments resulting from the 2.28 mm spacing of positions  130  in the preferred embodiment. 
     FIGS. 2 and 9 illustrate proximal end  70  of multifunction wire  66  having a hypotube segment  132  secured to the proximal end. The hypotube segment  132  has a flattened end  134  which is affixed to an elongate drive adapter  136 . The main body  138  (see FIG. 2) of drive adapter  136  has a generally circular cross section but with upper and lower recesses  140  sized to freely slide through a similarly shaped opening  142  formed in a first drive gear  144 . As seen in FIG. 9, each gear  144 ,  146 ,  148  is identical in construction even though only the first drive gear  144  needs to have the specialized shaped opening  142 . Third drive gear  148  engages internal gear  43  and second drive gear  146 . Second drive gear  146  acts as an idler gear and transmits motion from third drive gear  148  to first drive gear  144 . Therefore, rotating lateral deflection manipulator  38  causes the gear train including internal gear  43  and gears  148 ,  146 ,  144  to rotate and thus drive drive adapter  136  about its longitudinal axis thus rotating multifunction wire  66  about its longitudinal axis. This rotation of multifunction wire  66  is relatively free except where flattened distal portion  96  of multifunction wire  66  engages tip portion  12  through interfering torquing surfaces  100 ,  102 . 
     The proximal end  150  of drive adapter  136  is rotatably coupled to a second slider  76   a  through a rotary coupling  152 . See FIGS. 2 and 4. Rotary coupling  152  is clipped to slider  76   a  by a pair of clip arms  154 . Through clip arms  154  and rotary coupling  152 , proximal end  150  of drive adapter  136 , and thus proximal end  70  of multifunction wire  66 , is free to rotate relative to slider  76   a  but is not free to move longitudinally relative to slider  76   a . The longitudinal position of slider  76   a  is determined by the position of a curve size manipulator  32 , which is substantially identical to radial deflection manipulator  30 . Curve size manipulator  32  is coupled to slider  76   a  by a pin  108   a  which passes through a slot  112   a  formed in upper body part  26 . Sliders  76  and  76   a  have specially adapted portions for accommodating connection to the radial deflection wire  64  and multifunction wire  66 . Similarly, a pair of stops  120  can be used proximal and distal of slider  76   a  to limit the longitudinal movement of the slider. 
     During assembly of catheter assembly  2  the limits of movement of sliders  76  and  76   a  are determined by the placement of stops  120 . Undesirable corkscrewing or other deflection of tip portion  12  can be removed, or substancially removed, by rotating adjustment adapter  78  housed within T-slot  84 . After these adjustments have been made, upper and lower body parts  26 ,  28  are secured to one another, typically by ultrasonic welding. During use tip portion  12  can be moved in the direction of arrow  156 , from the dashed line position of FIG. 10, aligned with longitudinal axis  158 , o the solid line position of FIG. 10 by the movement of radial deflection manipulator  30  in a proximal direction. The size or radius of the curved tip portion  12  of FIG. 10 can be changed by the longitudinal movement of curved size manipulator  32 . Radially deflected tip portion  12  can be deflected laterally, that is in the direction of arrow  160 , by the rotation of lateral deflection manipulator  38 . In the preferred embodiment, through the use of stops  44 ,  46 , lateral deflection manipulator  38  is limited to movement of about 180° in each direction from a neutral or start position. However, by virtue of the gear ratios, one revolution of manipulator  38  results in four revolutions of first gear  44 . 
     Modification and variation can be made to the disclosed embodiment without departing from the subject of the invention as defined in the following claims. For example, instead of gears, friction drive elements could be used. Also, by appropriately positioning first gear  144  adjacent to internal gear  43  of lateral deflection manipulator  38 , the need for second and third gears  146 ,  148  would be eliminated; while a single gear could be used to replace gears  146 ,  148 , doing so would result in a reversal of rotary motion between the lateral deflection manipulator  38  and multifunction wire  66 , which is generally not desirable. Other drive schemes could be used to rotate multifunction wire  66 ; for example, first drive gear  144  could be coupled to manipulator  38  by a drive chain. In some situations a small electric motor could be used to rotate the proximal end  70  of multifunction wire  66 . Also, adjustment adapter  78  could be configured differently; for example, instead of using serrations at end  80 , cylindrical end  82  could have a hexagonal extension to permit the rotary orientation of adapter  73  to be changed using a wrench or similar tool.