Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical energy applicator
Reexamination Certificate
1998-09-18
2001-03-06
Jastrzab, Jeffrey R. (Department: 3737)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical energy applicator
C600S374000, C600S146000, C604S095030, C606S041000
Reexamination Certificate
active
06198974
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to catheters having steerable tips and particularly to a catheter having a tip which is steerable in two directions.
BACKGROUND OF THE INVENTION
Steerable or deflectable tip cardiovascular catheters are useful in many applications, being a marked improvement over catheters with fixed tips. They are especially useful in the field of electrophysiology for performing radio frequency ablation of cardiac tissue to interrupt abnormal electrical pathways in the heart.
There are presently several useful designs of steerable tip catheters. One such steerable tip catheter is described in Reissue Pat. No. 34,502. The catheter has an elongated catheter body and tip portion which can be deflected into a semi-circle in one direction. In addition, the catheter body and tip portion can be rotated. Therefore by tip deflection, catheter rotation and catheter translation, i.e., lengthwise movement of the catheter, contact of the tip portion with most areas of a heart chamber may be made.
There are, however, structures and irregularity in the heart chambers which often make access to a particular location difficult. In some cases it is necessary to reach around obstacles to contact a desired site. Moreover, it may be necessary to use a longer or shorter deflectable tip portion to reach a particular site and maintain adequate stable contact.
One early multidirectional deflectable tip catheter had a catheter body and tip with
5
lumens, i.e., a central lumen and four outer lumens disposed symmetrically around the central lumen. This catheter had four puller wires which extended through the outer lumens. The distal ends of the puller wires were attached to a ring at the tip and the proximal ends were attached to a “joy stick”. The central lumen was open at its distal end and connected to a luer hub at its proximal end. This catheter had no reinforcement in its body or tip. It was not suitable for electrophysiology because it had effectively no torque transmission to the tip which made tip rotation difficult. Moreover, the catheter body was subject to the same deflection as the tip, but to a lesser degree.
A more recent steerable catheter has a steerable tip that is controlled by a bendable control handle. Multiple puller wires connect the steerable tip to this control handle which can be bent in any direction and can be thought of as a multiple ball joint with friction. The tip, once deflected, can be further deflected laterally by an internal stylette. The disadvantage of this catheter design is that the tip is very soft and has poor lateral stiffness due to the presence of the stylette which cannot transmit torque effectively. Because of this, an electrode at the tip of the catheter cannot be held firmly against the myocardial wall.
Another recent steerable tip catheter comprises a deflectable tip which can be deflected in one direction by a puller wire and further deflected laterally by an internal stylette. The stylette can also be moved axially within the catheter to change the shape of the tip curvature.
The disadvantage of this catheter design is that the lateral stiffness of the tip is dependent upon the stylette which cannot transmit torque effectively.
In a design wherein the tip is rotated by means of a stylette, it follows that the lateral stiffness of the tip must be less than that of the stylette alone. This is because some torque from the stylette is required to rotate the tip. Moreover, the stylet must be kept small to allow the catheter body and tip to bend and to be safe within the patient body and heart.
SUMMARY OF THE INVENTION
The present invention provides a cardiovascular catheter comprising a steerable catheter tip section, an elongated catheter body and a control handle. The catheter tip section comprises at least two generally diametrically opposed off-axis lumens, and preferably an axial lumen.
The catheter body comprises at least one lumen in communication with the off-axis lumens of the catheter tip section. Preferably, the catheter body comprises a single central lumen in communication with each of the off-axis lumens in the catheter tip section.
The catheter comprises two pairs of elongated puller wires which extend through the lumen(s) of the catheter body and into the off-axis lumens in the catheter tip section. One pair of puller wires extends into one off-axis lumen or lumen pair of the tip section and the other puller wire pair extends into the diametrically opposed off axis lumen or lumen pair in the tip section. The distal ends of the puller wires are anchored to the tip section. Each pair of puller wires comprises a long and a short puller wire, the short puller wire of the pair being anchored at a location within the tip section proximal to the anchor location of the long puller wire of the pair. A compression coil extends through the catheter body in surrounding relation to each puller wire for resisting compression forces on the catheter body when a puller wire is moved in a proximal direction relative to the catheter body. The proximal end of each compression coil is fixedly attached to the proximal end of the catheter body, and the distal end of the compression coil is fixedly attached to the distal end of the catheter body and/or at a selected location along the length of the catheter tip section. The site of attachment of the distal end of the compression coil and the anchor site of the puller wire associated with that compression coil in the tip section determine the length of the tip deflection curvature in the direction of that puller wire.
Longitudinal movement of the puller wires and hence deflection of the tip section is accomplished by means of the control handle. A preferred control handle comprises a handle body having four movable, preferably slidable, members. Each movable member is connected to a puller wire so that movement, preferably in a proximal direction, of a movable member from a first position towards a second position results in proximal movement of the puller wire associated with that member with respect to the catheter body and deflection of the tip section in the direction of the off-axis lumen containing that puller wire.
In a preferred embodiment, the long puller wire from each pair of puller wires is anchored at a first location adjacent to the distal end of the tip section, preferably anchored to a tip electrode. The short puller wire from each pair is anchored to the side wall of the tip section at a second location spaced-apart proximally from the distal end of the tip section, preferably at about the mid-point of the tip section. The distal ends of the compression coils surrounding the short puller wires are fixedly attached to either the distal end of the catheter body or the proximal end of the tip section. The distal ends of the compression coils surrounding the long puller wires are also fixedly attached to either the distal end of the catheter body or the proximal end of the tip section. Alternatively, the distal ends of the compression coils surrounding the long puller wires are attached to the tip section at a position adjacent the anchor sites of the short puller wire the tip section adjacent the second location.
Proximal movement of a short puller wire of the pair of puller wires results in a first curve in the direction of that short puller wire between the distal end of the compression coil surrounding that puller wire, e.g, the distal end of the catheter body and the location where the puller wire is anchored. Proximal movement of the long puller wire of the same pair will result in a continuation of that curve resulting in the deflection of the tip section into a generally planar. Alternatively, proximal movement of the long puller wire of the diametrically opposite pair of puller wires results in a second curve in a direction opposite the first curve from the distal end of the compression coil surrounding that puller wire, i.e., the second location, and the distal end of the catheter tip section. The result is a generally planar “S” shaped curve.
In another pref
Christie Parker & Hale LLP
Cordis Webster, Inc.
Jastrzab Jeffrey R.
LandOfFree
Bi-directional steerable catheter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bi-directional steerable catheter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bi-directional steerable catheter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2509807