Catheter tip assembled with a spring

Inventors

Richter, Jacob • CHAPPEL, Shlomit

Assignees

Medinol Ltd

Abstract

A catheter tip having a spring element that imparts longitudinal flexibility, pushability and radial rigidity to the catheter tip, thereby improving deliverability, is provided. The spring element also provides radial support to the distal edge of the catheter tip. The spring element may taper distally, but may have a substantially constant inner luminal diameter. The spring element may be partially covered or embedded, leaving its distal end exposed. The spring element may also include spaced coils in a proximal region. The apparatus may be used with any interventional catheter system, but is particularly suitable for use with balloon-expandable stent systems and balloon-angioplasty systems, where flexibility of the catheter tip and minimal flaring of the distal edge of the catheter tip is desirable.

Core Innovation

The invention provides an endovascular catheter tip in which the distal-most spring element supplies longitudinal flexibility, pushability, and radial rigidity. The flexible catheter tip is configured to reduce distal-edge catching/flaring and to reduce kinking or buckling when delivered through tortuous or stenotic vessels.

The spring element is implemented as a wire coil defining an inner lumen having an inner luminal diameter and an outer diameter. The coil includes pitch space between two or more coils in a first region and tightly packed coils in a second region, with the second region distal of the first region.

The spring element also has a decreasing cross-sectional diameter from a proximal end to a distal end, with the outer diameter tapering distally. The inner luminal diameter is constant or tapers at a lesser rate than the outer diameter of the spring element, and the distal end may be left exposed for bonding or embedded/partially covered by a jacket while maintaining a smooth distal end.

The disclosed construction is described as improving deliverability compared with conventional stiff plastic tips, including minimized distal edge protrusion and reduced kinking. The document further notes that radio-opacity may be improved and describes example smoothing or joining approaches for the distal region, including laser polishing/welding or an adhesive bond.

Claims Coverage

The document provides two independent claims. Across the independent claims, the inventive core is the distal flexible catheter tip that uses a wire-coil spring element with a spaced-coil proximal region transitioning to tightly packed distal coils, combined with a decreasing spring cross-sectional diameter toward the distal-most end and a constrained inner-lumen geometry relative to the outer diameter taper.

Together, the independent claims require a distal flexible catheter tip formed by a wire-coil spring with a proximal pitch-space region and a distal tightly packed region, a decreasing coil cross-sectional diameter toward the distal end, and an inner-lumen geometry that is constant or tapers at a lesser rate than the outer diameter.

Stated Advantages

Documented Applications